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News and Discussions => Nuke News => Topic started by: ddm502001 on Aug 30, 2006, 04:22

Title: Best New Reactor Design
Post by: ddm502001 on Aug 30, 2006, 04:22
All readers, you need to see the abhorant piece of work; the EPR from Areva.  Go to AREVA EPR and view thru the files to the vid and photo sections.  Reminders of 'the day' are ever present and if they do start building these in the US we could see a repeat of SATSOP and Midland to name a couple.

This plant design is not GEN III, it is the same old tired seventies nuke we all are used to as a PWR, someone needs to take some initiatve and stop them.  Less pumps? Less Valves? how with four safety trains and four safety diesels as well as two non safety. The faster build for ESBWR and the AP 600-1000 units will revive our industry, this "Robust" megalithic monument to our Navy leadership could end up as our industry's demise.

Olkiluoto 3 is being built in Finland and is a EPR, it started in 04/2004, they are just now pouring the can walls.  Six+, maybe 7-8 years construct time given the inevitable problems and less than 4 years for either the ESBWR or the APs', the proof is in the product or for us the production(of MW).

old coot
Title: Best New Reactor Design
Post by: Rennhack on Aug 31, 2006, 07:48
No agenda there, eh?
Title: Best New Reactor Design
Post by: ddm502001 on Aug 31, 2006, 08:51
Not an agenda, just common sense.  The longer the build time the more apt to be addressed by public opinion as 'bad', also the longer build gives an open to cost overruns by changing economic conditions, remember the Reagan years of 20% interest rates?

If we can build a good partnership with the public AND decrease CO2 deposition in our atmosphere in a 'reasonable' time frame we could see a resurgence in our industry to rival the sixties.

Bigger, more armored, more delivered MW, for what tradeoffs, too long to build, monstrous for day to day surveilances, potential for a 'negative' public opinion built on the fact this new design is more aircraft attack resistant. I mean, come on, if a aircraft attack is that imminent on Nuclear sites then just don't build them, and this is an opinion of my neighbors and friends.  Oh and 1600mw dump on a trip could be too much strain on grid lines.  To me, the plant is like asking congress to allocate money to build nuke powered 'Montana' class battleships as they are bigger, more armored, and more 'impressive' than the Burke class destroyers we currently have built.

Getting AP 600-1000s' or ABWR's or ESBWR's built in 3-4 years is the answer.  Prove to our public that we can build in a reasonable time frame and build 'Safe' plants as determined by NRC guidelines, but NOT get stupid and go for broke on more monuments to the futility of mans' ego and paranoia.

old coot
Title: Best New Reactor Design
Post by: ChiefRocscooter on Aug 31, 2006, 09:07
Ok since you mentioned it
                                       1980    1985   1990   1995   2000   2001    2002
Federal funds, effective rate 13.35% 8.10% 8.10% 5.83% 6.24% 3.88% 1.67%
Prime rate charged by banks 15.26    9.93   10.01   8.83   9.23    6.91    4.67

Not show was that it went from 7% to almost 17% under Carter!! for 1976 to 1980
So It was Carters intrest rate problem that we are talking about (boy he did good thing for nuke power did'nt he!) And as a side not you will she that thru the 90's Clinton managed to hold the line on rates (well they did go up a bit while Ronnie managed to cut them in half in his eight years!)

Ok we now resume our more informed regular brodcast! :P
Title: Best New Reactor Design
Post by: ddm502001 on Aug 31, 2006, 09:48
And the rest of my retort gets no attention?

old coot
Title: Best New Reactor Design
Post by: ChiefRocscooter on Aug 31, 2006, 10:20
Well you started on a false premise so I had to correct that :)

As for the rest I would not be so bold as to think I know enough about the "Big" picture in civ world to make rational statements about what you are suggesting  I will leave that to those more knowledgable of current plants and design/construction practices.
Title: Best New Reactor Design
Post by: Roll Tide on Aug 31, 2006, 10:48
And the rest of my retort gets no attention?

old coot

I can give you a hearty AMEN on most of what you wrote. AP1000 should IMHO be the new standard. An ABWR is still a BWR; when you explain the difference to the public, no community that I know would prefer a BWR in their backyard.

More trains is ridiculous. That means the amount of surveillance for 1 new unit as currently employed by a current 2 unit site.
Title: Best New Reactor Design
Post by: Rennhack on Aug 31, 2006, 10:59
1000 MWe vs 1400 MWe

Simple math.
Title: Best New Reactor Design
Post by: Roll Tide on Aug 31, 2006, 12:28
1000 MWe vs 1400 MWe

Simple math.

1400 MWe from an undesirable neighbor vs. 1000 MWe from a more desirable neighbor. FP&L even has switchyards andpower plants disguised as subdivisions and condos. When the simple math isn't politically expedient, it won't work.
Title: Best New Reactor Design
Post by: ddm502001 on Aug 31, 2006, 03:01
Based on discussion from Westinghouse and inplant engineering, AP or ESBWR either could be completed in three+ years from actual start.  No need to do the EPR for six to seven. as two AP's could be concurrently built making 2000mw as opposed to 1400 same time frame.

As to the four safety trains, the NRC hasn't completely bought off on allowing one or possibly two out of service for extended durations as taken by some managers.  That would mean keeping them all operable ALL of mode 1 time.  (Region 4 rep input)This would make the EPR an undesireable mess if not job security for some.

Sorry for the exaggerated interest level, but in the 80's I was paying almost 17% on a home loan, and Reagan took quite a few shots for his stay in the white house during my plants coming of age.

As to the civ world, well I came to nuke power from the civ world late in life and have no Navy time.  My contacts in the 'real' world or civvy area are plentiful as well as opinionated so I take their input accordingly.

old coot
Title: Best New Reactor Design
Post by: M1Ark on Aug 31, 2006, 08:06
I can give you a hearty AMEN on most of what you wrote. AP1000 should IMHO be the new standard. An ABWR is still a BWR; when you explain the difference to the public, no community that I know would prefer a BWR in their backyard.

More trains is ridiculous. That means the amount of surveillance for 1 new unit as currently employed by a current 2 unit site.

The community you know would pick a BWR when you tell them it's inherently safer and present them with inteligent point counter-point from someone who knows both designs. 

Make sure you phrase your rebutal with known facts.
Title: Best New Reactor Design
Post by: Fermi2 on Aug 31, 2006, 08:13
I'm curious as to why they wouldn't want a BWR in their back yard?

Mike
Title: Re: Best New Reactor Design
Post by: M1Ark on Sep 01, 2006, 10:16
Fermi has 4 trains and is a single unit 1200 MWe plant.  That means 4 LPSI, 4 CS, 4 4160v safety busses and 4 EDG's.  They operate under the division concept with 2 trains per division. When I read the EPR safety system design it reminded me of how Fermi is designed.  Also,  you cannot take any of the components out of service for an extended lenght of time.  You need all trains and all safety systems operable to meet the LCO in Mode 1 operation.  I believe other plants employ this same concept of 4 trains.  I originally thought this was due to the size of the core.  I'm not sure if that's true (<1000 MWe = 2 trains with a swing train.  >1000MWe = 4 trains).  Anybody know of other plants having 4 trains that is currently in operation?
Title: Re: Best New Reactor Design
Post by: Nuclear NASCAR on Sep 01, 2006, 12:22
If I'm not mistaken, doesn't South Texas or Comanche Peak have 3 safety trains? 
Title: Re: Best New Reactor Design
Post by: Roll Tide on Sep 01, 2006, 01:18
I'm curious as to why they wouldn't want a BWR in their back yard?

Mike

ALARA
Compare release rates to the public and dose to workers.
Title: Re: Best New Reactor Design
Post by: Roll Tide on Sep 01, 2006, 01:32
The community you know would pick a BWR when you tell them it's inherently safer and present them with inteligent point counter-point from someone who knows both designs. 

Make sure you phrase your rebutal with known facts.

I have seen no indications that ABWR is inherently safer than AP1000. Show me.

Until then, I will consider it a choice of dollars over dose (more MW but more Rem). I am glad I won't have to sit in a meeting at Northeast Community College (Rainsville, AL) or Scottsboro (AL) High School auditorium and defend an ABWR choice for Bellefonte.
Title: Re: Best New Reactor Design
Post by: Fermi2 on Sep 01, 2006, 02:54
ALARA
Compare release rates to the public and dose to workers.

If you're talking Gaseous release the release rate at most BWRs is roughly the same as at a PWR. Liquid releases are not even close as most BWRs never have to release liquid to the environment.

As for dose, hmmmm, I can tell you this, the BWR I came from had far lower doses than the PWR at which I currently work, and we never came near the total dose that I've seen in two outages here. I get more dose in an Aux Building tour than I'd get in a week of reactor building tours at my old BWR.

If you pop a fuel rod at a BWR its not all that major and doesn't effect outage dose rates like in a PWR.

The ABWR has no piping below core level, and as for Emergency Operation I'd take a BWR over a PWR under most circumstances. Having about an adundance of ways to determine reactor water level over the core is a darn nice thing!!.


I'm of the same opinion as M1Ark, if you haven't operated or been trained on both types you cannot make a reasonable comparison.

Operationally I like Westinghouse 4 Loop PWRs as they are simple and easy to understand. I believe if you look into the historical top performers in the world they tend to be large Westinghouse Reactors.


Mike
Title: Re: Best New Reactor Design
Post by: Fermi2 on Sep 01, 2006, 04:18
Technically if you read a BWR 4 UFSAR and the DBDs there aren't 4 trains of LP ECCS. There are two trains which operate under different regimes for 4 total subsystems. The UFSAR only takes credit for each subsystem under certain circumstances but it in fact calls one divsion of RHR and one of Core Spray a single train. In fact, under the BWR Analysis for Fermi there's only really a 1.5 trains as the LOCA Analysis credits the need for 3 of the 4 RHR Pumps.

The biggest weakness of a BWR 4 and below is the HP ECCS. Given there's only one real train of injection I always thought having a system that would automatically blow down the reactor by creating a bigger leak was hokey at best.

Mike
Title: Re: Best New Reactor Design
Post by: M1Ark on Sep 02, 2006, 07:04
Mike,

I fully understand what you are saying.  The term train isn't really discussed under Fermi UFSAR.  Neither is the term division in my current plants UFSAR.  I'm just saying the structure of Fermi's ECCS would be considered as having 4 trains by operators and engineers at my current plant.  Fermi has as many EDG's and ECCS pumps as my two unit plant producing 1800 MWe.  Also,  each of Fermi's pumps are at least twice as big. (~10,000 gpm total ECCS flow per rx vs. ~ 80,000 gpm total ECCS flow)

Areva's EPR ECCS reminds me of Fermi's ECCS.

M1Ark
Title: Re: Best New Reactor Design
Post by: M1Ark on Sep 02, 2006, 07:14
I have seen no indications that ABWR is inherently safer than AP1000. Show me.

Until then, I will consider it a choice of dollars over dose (more MW but more Rem). I am glad I won't have to sit in a meeting at Northeast Community College (Rainsville, AL) or Scottsboro (AL) High School auditorium and defend an ABWR choice for Bellefonte.

Current BWR's are designed for 10 minutes of no operator action  and the new BWR's are designed for 3 hours of no operator action during a DBA accident.

Roll Tide,

I could go on and on with specific details but until you get a BWR license it would be pointless.  Forgive my lack of patience... I have a small pet peeve about people speaking about subjects they know little about.

Both reactor designs are safe.  I take professional exception to your comment of your community not wanting a BWR in their backyard.

FPL will probably build a couple of the French Areva EPR's in South Florida.  I wished it was an AP1000 or the ABWR/ESBWR.  Either of the American designs would be better IMHO. 
Title: Re: Best New Reactor Design
Post by: Fermi2 on Sep 02, 2006, 12:08
Your point well taken M1Ark. I remember the first time I used the word Division here and I got that blank look, then the laughter when I was told I'm in the real reactor world now LOL. (Imagine the hilarity when I instructed an operator to trip and isolate recirc pumps on a seal failure!) One thing that really baffles me is with SO much ECCS Flow available in a BWR why taking out an LP ECCS Pump was so limiting, YET when HPCI was Inoperable I could take credit for RCIC for a period of time, even though it was 10% the flow of HPCI. Another thing I find strange is in a Westinghouse PWR part of ECCS System Operability is based on being able to line up Sump Recirc to the High Pressure Pump, yet none of it occurs automatically (with the exception of the suction line up to RHR).

My opinion is building an EPR is a mistake. Granted it has 4 trains but why choose what in my mind is a status quo design when you can get an ESBWR or AP1000 or even an ABWR all of which are really at least .5 generations ahead of the EPR.

The first 10 minutes of a Reactor Trip in a PWR are FAR more hectic than in a BWR. There's really one immediate action in a BWR which is to verify the trip. Then usually no one talks for at least a minute while the plant is assessed and the SRO gets out the EOP. No safety systems start, nothing really repositions except a the Control Rods and the feed system lining up for post trip feed.

I'd have no problem with either type of reactor being built anywhere near my house.

Mike
Title: Re: Best New Reactor Design
Post by: Kernwerker on Dec 05, 2006, 05:01
[ no community that I know would prefer a BWR in their backyard.

[/quote]

I am surprsed that the public in the States actually "do" know the difference between a PWR and BWR. Here in Germany its a different story, nuke is nuke so its bad that simple.
Title: Re: Best New Reactor Design
Post by: Kernwerker on Dec 05, 2006, 05:10
if you look into the historical top performers in the world they tend to be large Westinghouse Reactors.


Mike

[/quote]

Woaa is this some kind of PR Website for US nukes? Well the top 10 nuclear reactors in performance with one or two exceptions (I think it was Dresden) are all from Germany.
All of the 1400 MWe 4 loop PWR's that where built in Germany are under the top 10 in the World in performance
Title: Re: Best New Reactor Design
Post by: Marlin on Dec 05, 2006, 06:25
I am surprsed that the public in the States actually "do" know the difference between a PWR and BWR. Here in Germany its a different story, nuke is nuke so its bad that simple.

They don't typically know the difference. Normally they are happy that thier tax base is high, or are NIMBY (not in my back yard).
Title: Re: Best New Reactor Design
Post by: Marlin on Dec 05, 2006, 06:26
Woaa is this some kind of PR Website for US nukes? Well the top 10 nuclear reactors in performance with one or two exceptions (I think it was Dresden) are all from Germany.
All of the 1400 MWe 4 loop PWR's that where built in Germany are under the top 10 in the World in performance

Karma point your way for civic pride.
 :)
Title: Re: Best New Reactor Design
Post by: Roll Tide on Dec 05, 2006, 07:33
Roll Tide,

I could go on and on with specific details but until you get a BWR license it would be pointless.  Forgive my lack of patience... I have a small pet peeve about people speaking about subjects they know little about.

Both reactor designs are safe.  I take professional exception to your comment of your community not wanting a BWR in their backyard.

As a previously PWR licensed RO, my understanding of a BWR is greater than that of the general public. I also have worked at a BWR, but not in OPS. When I was a contract HP tech, I experienced a vast difference in dose received by the workers at BWRs vs. PWRs. PWR off-gas releases should have more impact than BWR liquid releases, though both have been evaluated as acceptable levels.

As a former Navy Nuke, I realize that I am prejudiced against intentionally boiling in the core. Based on much of the PR from the Navy's days of building a nuke fleet, there is a similar consensus among relatively informed members of my community.

You are free to take professional exception to my preference for an AP1000 over an ABWR in my community, but the community already has their own desires. Before you ignore this group as an ignorant bunch of farmers, realize that many retired there after construction halted on Bellefonte. Few are operators, but many participated in construction of TVAN and other nuclear plants. Some came out of retirement to work the Browns Ferry Unit 1 Restart, along with the children and grandchildren of that generation of nukeworkers.

You don't have to be patient with me. But with the general public it would be useful. And these threads can be researched by members of communities considering new nuclear plants. A proponent of the ABWR should provide a defense of that design that could be followed by the general public, or at least by a Nukeworker.
Title: Re: Best New Reactor Design
Post by: BuddyThePug on Dec 05, 2006, 12:52
If you're talking Gaseous release the release rate at most BWRs is roughly the same as at a PWR. Liquid releases are not even close as most BWRs never have to release liquid to the environment.

As for dose, hmmmm, I can tell you this, the BWR I came from had far lower doses than the PWR at which I currently work, and we never came near the total dose that I've seen in two outages here. I get more dose in an Aux Building tour than I'd get in a week of reactor building tours at my old BWR.

If you pop a fuel rod at a BWR its not all that major and doesn't effect outage dose rates like in a PWR.


I also got a lot less dose from being up-close and personal on the BWR turbine, than I did in the world of tiny boric acid leaks bringing CRUD to ya in the PWR world.

Once H2 injection went in, there were some streamers and higher dose rates in a few select portions of the BWR piping.

My major concern with BWR over PWR comes from the scenario where a BWR has been running a 24 month cycle MOX fuel, you're at EOL, and a 100% load reject occurs. Seems that with voids gone, the SDM is really low. Yes,a  PWR under similar scenario with a MS line break could get there as well, but load rejects are a lot more common.

Another minor feature about PWRs is that with the Rx vessel slightly below ground level, is the ability to gravity feed additional borated water sources.

Overall, having worked a bit in both types, I wouldnt have a problem living at 5281 ft from vessel center on either design. Remember, TMI and Davis-Besse are both PWRs. It depends more on diligence of Maint. and Ops. , we have good plant designs and containments.

On a side note, nuclear side VPs like to push for large units (1300MW if we can get it , yessiree) for perceived economies of scale (fewer bodies/MW). Which is fine, but it means that 1. You are the MSSC in your reserve sharing group, and someone is burning a lot of coal to provide spinning reserve, and 2. An extended outage at a 1300MW is much pricier than buying replacement power for a 600MW unit. If memory serves me right, most of the 6 to 9 month outages from hell have been at large PWRs, yes?

Title: Re: Best New Reactor Design
Post by: M1Ark on Dec 05, 2006, 05:26
As a previously PWR licensed RO, my understanding of a BWR is greater than that of the general public. I also have worked at a BWR, but not in OPS. When I was a contract HP tech, I experienced a vast difference in dose received by the workers at BWRs vs. PWRs. PWR off-gas releases should have more impact than BWR liquid releases, though both have been evaluated as acceptable levels.

As a former Navy Nuke, I realize that I am prejudiced against intentionally boiling in the core. Based on much of the PR from the Navy's days of building a nuke fleet, there is a similar consensus among relatively informed members of my community.

You are free to take professional exception to my preference for an AP1000 over an ABWR in my community, but the community already has their own desires. Before you ignore this group as an ignorant bunch of farmers, realize that many retired there after construction halted on Bellefonte. Few are operators, but many participated in construction of TVAN and other nuclear plants. Some came out of retirement to work the Browns Ferry Unit 1 Restart, along with the children and grandchildren of that generation of nukeworkers.

You don't have to be patient with me. But with the general public it would be useful. And these threads can be researched by members of communities considering new nuclear plants. A proponent of the ABWR should provide a defense of that design that could be followed by the general public, or at least by a Nukeworker.

I am also a former navy nuke and former BWR SRO and curently a PWR SRO working with RO's like yourself and if you knew twice as much as them on BWR operations you'd still know next to nothing.

I accept that your biased towards PWR.  I'm telling you both designs are good.
Title: Re: Best New Reactor Design
Post by: M1Ark on Dec 05, 2006, 05:49

My major concern with BWR over PWR comes from the scenario where a BWR has been running a 24 month cycle MOX fuel, you're at EOL, and a 100% load reject occurs. Seems that with voids gone, the SDM is really low. Yes,a  PWR under similar scenario with a MS line break could get there as well, but load rejects are a lot more common.

Most PWR people equate voids with boron concentration where boron concentration gets really low at EOC.  Voids never really go away.  BWR's have twice the number of control rods as a PWR and SDM is never an issue as it pertains to your scenario.  BWR Rx Power goes down on a MS Line break (it shuts itself down).  BWR Rx Power goes down when it losses vessel inventory such as a LOCA (it shuts itself down).

Another minor feature about PWRs is that with the Rx vessel slightly below ground level, is the ability to gravity feed additional borated water sources.

BWR's do not use boron.  SDM acomplished by rods.

Overall, having worked a bit in both types, I wouldnt have a problem living at 5281 ft from vessel center on either design. Remember, TMI and Davis-Besse are both PWRs. It depends more on diligence of Maint. and Ops. , we have good plant designs and containments.

Absolutely agree.

On a side note, nuclear side VPs like to push for large units (1300MW if we can get it , yessiree) for perceived economies of scale (fewer bodies/MW). Which is fine, but it means that 1. You are the MSSC in your reserve sharing group, and someone is burning a lot of coal to provide spinning reserve, and 2. An extended outage at a 1300MW is much pricier than buying replacement power for a 600MW unit. If memory serves me right, most of the 6 to 9 month outages from hell have been at large PWRs, yes?

Right again.  ESBWR designs only advantage is it's 1500 mw vs. 1000 mw for the AP1000

Which one flies better?  A helicopter or an airplane?  Depends on the application and what you are trying to accomplish.  This is similar to the BWR vs. PWR argument.  Both Rx designs are brilliant.  Really knowing both designs at a level higher than what's listed on Wikipedia allows one to appreciate the finer points of both designs.

Title: Re: Best New Reactor Design
Post by: BuddyThePug on Dec 05, 2006, 05:59
If you are going to quote, please dont MISquote. OF course an MS line break lowers BWR power due to voids, that why I used it as a PWR example. No one said BWRs use boron, was used as a PWR example. NO one cited Wikipedia. -5 for some lack of reading comprehension there shipmate.
Title: Re: Best New Reactor Design
Post by: Charles U Farley on Dec 06, 2006, 01:07
All right, Susies, this is almost like a Navy 8G versus 6G "You guys do what with your reactor?!?!" argument---I was hoping to never have one or hear one again.   ;)
Title: Re: Best New Reactor Design
Post by: Roll Tide on Dec 06, 2006, 10:36
I am also a former navy nuke and former BWR SRO and curently a PWR SRO working with RO's like yourself and if you knew twice as much as them on BWR operations you'd still know next to nothing.


Your Honor,
I motion that you strike the last from the record as non-responsive.


OK, lacking Judge Wapner's input, let's try again. You consider the BWR at least as good overall as the PWR. But you either can't explain it to a Nukeworker (typical or otherwise) or just consider it beneath you. Put a little effort into it, because I am sure I am not the only one who really would like to hear this.
Title: Re: Best New Reactor Design
Post by: Roll Tide on Dec 06, 2006, 11:18
As for dose, hmmmm, I can tell you this, the BWR I came from had far lower doses than the PWR at which I currently work, and we never came near the total dose that I've seen in two outages here. I get more dose in an Aux Building tour than I'd get in a week of reactor building tours at my old BWR.

You must have used a lot of cameras on the BWR, and gone a lot of out of the way places on the PWR to get those results.

According to INPO, there are very few US BWRs with lower dose than any US PWRs (would be 0, but SGRP and head inspections takes a toll). The "one year dose normalized for a full cycle" data looks like this:

Best 10%                           PWR 39Rem               BWR 90Rem
Best Quartile                      PWR 44Rem                BWR 108Rem
Median                              PWR 60Rem                BWR 133Rem
 

Glad you didn't pick it up, but somebody did!                         
Title: Re: Best New Reactor Design
Post by: M1Ark on Dec 06, 2006, 06:11
If you are going to quote, please dont MISquote. OF course an MS line break lowers BWR power due to voids, that why I used it as a PWR example. No one said BWRs use boron, was used as a PWR example. NO one cited Wikipedia. -5 for some lack of reading comprehension there shipmate.

Sorry Buddy,


I tried to answer you and Rolltide at the same time. I didn't mean to upset you.  It's hard to get ones point across correctly in an email or forum.  I agreed with most of what you said.

The Wikipedia comment was for Rolltide along with the inherently conservative design of the BWR over the PWR on an ESDE and LOCA.

The only thing you said that was not true was that SDM was an issue for a BWR at EOC.

Rolltide,

License class is 18 months long and I will not argue the specifics with you.  If you really must know talk to Broadzilla.  He will tell you the merits of each design in excrutiating detail.  I am an amateur compared to him.  You are correct in that dose to employees is much lower on a PWR.  But please don't equate this to dose to the public.  Broadzilla is correct in that my previous BWR had lower dose than my current PWR. Some BWR's built their secondary like a PWR and some built their secondary like an Egyptian Pyramid.  4 to 8 foot thick concrete floors, walls and ceilings.

When you weigh all of the facts both designs are good and safe and the economy of scale will prevail as to which designs will be built.

P.S.  Thanks for the Karma, Rolltide.
Title: Re: Best New Reactor Design
Post by: tr on Dec 16, 2006, 03:27
Just to clarify, the AP1000 is actually an 1150 MWe plant (http://www.westinghousenuclear.com/AP1000/index.shtm).   

Regarding which plant is safer, the PWR core damage frequencies are as follows per MIT (http://web.mit.edu/erc/docs/scourse/28.FridayPM.Buongiorno.pdf):

EPR:   4x10(-7)
AP1000:  5.09x10(-7)

The BWR core damage frequencies are as follows per a magazine article (http://ecow.engr.wisc.edu/cgi-bin/getbig/ne/550/witt/literature/esbwr_mps_2005.pdf):

ABWR:  2x10(-7)
ESBWR: 2x10(-7)

As a former BWR SRO/STA, and a current PWR safety analyst, I'll take the BWR with its 2000+ gpm of ECCS flow directly to the core at operating pressure over a PWR with its 0 (for CE plant) to 1000? (W plant) of ECCS flow to the loops (with the associated business of how much actually gets to the core).  You can actually keep a BWR cool with the entire bottom head of the vessel gone, if it weren't for the fact that the assemblies would fall out!

There's also something about a BWR where once you put the rods in, the thing stays shutdown.  No worries about having to borate to get down to cold shutdown.
Title: Re: Best New Reactor Design
Post by: M1Ark on Dec 16, 2006, 05:05
Well stated tr.  You must have been at a small bwr.  The BWR I was at could inject 6000 gpm of ECCS flow at rated pressure and ~ 80,000 gpm at lower pressures using all available sources.  The point about not having boric acid to maintain SDM is also a big factor. My current CE plant CDF is ~3x10-5.
Title: Re: Best New Reactor Design
Post by: Fermi2 on Dec 16, 2006, 10:04
An RHR Pump at my old plant is bigger than the entire ECCS at a Westinghouse 4 Loop PWR. Of course the design analysis says you need that kind of flow the reactor and core is physically a LOT bigger. But so far as water sources there's a lot more available ones because most plants can inject their BOP water into the core.

As for Mixed Fuel EOL I don't understand the concern. Without being able to make the required Shutdown Margin and Rod SCRAM time post accident you couldn't operate the plant anyway. The concern isn't so much being able to hold the reactor SD, in a BWR they'll always be able to do that, the concern is being able to control the transient via a SCRAM before MCPR reaches certain limits. it's a rather moot point anyway as a BWR 4 operating in the MELL or MEOD region breeds quite a bit of Plutonium and and in fact roughly 60 to 70% of the fissions at EOL are Plutonium based anyway. One time Fermi didn't load enough fuel to make it to the end of a cycle without an early coast down so they intentionally operated high in the MELL/MEOD region very early in core life and performed Control Rod Pattern Adjustments with the intent of breeding even more Plutonium. That was a couple cycles before M1Ark got there and IIRC it didn't matter as that was the cycle we broke something which caused a SD of sufficient length that we'd have enough Uranium.

Again I like both Machines. A Westinghouse 4 Loop PWR is a wonderful reactor with a lot of design margin, but one thing I noticed, it seems there is always a crunch on making and finding sufficient borated Water to supply everything we use it for during an outage, in fact it seems the Operator who can figure out the where's and whens is somewhat a wizard. We didn't have that problem in a BWR. You made a water plan before the outage and so long as you stuck with it you'd be ok. Then again the plants on the great Lakes weren't allowed to discharge so we had to be good with the water plan.

PWR have a higher CDF mostly due to the fact they have to rely on more active components to align to the Containment Sump and they're subject to seal failures.

One thing I really liked about a BWR is the multiple water level indications you had for actual reactor water level without having to derive anything. Also given the design analysis supports having 1/3 of the length of the fuel assembly uncovered without causing significant core damage is a BIG Plus.

On the other hand, too many times the BWR 4 EOPs require prioritization especially due to containment issues. It can be hectic. I'll show you a difference, in the WEstinghouse PWR World if you get an ATWS the Analysis shows you have 10 minutes to shut down the reactor, if not you risk breaking the vessel. In the BWR world in some cases you have less than 2 minutes to complete a LOT of EOP Actions (ATWS with a closure of MSIVs or ATWS due to Turbine Trip W/O Bypass. Many of these actions are geared towards protecting the containment and get VERY VERY hectic. It's a reason ATWS Instrumentation and systems are in BWR TEch Specs and IIRC are the most limiting Instrumentation Specs (2 hours allowed out of service and 1 hour testing IIRC)

Personally I like both types of plants but if you are gonna compare the two in any reasonable fashion the only way to do so is to be licensed as either an RO or SRO on both types. opinions are all great an OK and of course welcome, but to state anything in absolute without having operated either type probably isn't the best way to keep an open mind.

Mike
Title: Re: Best New Reactor Design
Post by: retired nuke on Dec 16, 2006, 12:56
Hmmm Broadzilla - you may be right about expressing opinions only if you are licensed in both. Your explanation was so far over my head that I didn't even feel the breeze as it went by.
Being a humble RP tech, I prefer plants that run continuously between outages, require minimal major online maintenance, and keep the utility's pocket full enough that my paycheck is always on time. About any approved design will accomplish that if properly run and maintained.

Thanks to all of you operator types for the opinions and explanations - I am slowly learning more about our industry future from this forum - much more than I am learning at my plant....
Title: Re: Best New Reactor Design
Post by: tr on Dec 16, 2006, 02:33
M1Ark,

Actually, I was at the second largest US BWR (Perry).  Due to the BWR6 HPCS pump being motor driven, it gave less flow at rated pressure than the older HPCI systems did (qualification - it's been over 10 years since I was there, the memory cells for the actual numbers may have died!). 
Title: Re: Best New Reactor Design
Post by: M1Ark on Dec 16, 2006, 07:05
Broadzilla,

Excellent writeup.  I understood it 100%.  I felt that as I was reading your comments it would go over even an licensed PWR guys head.  This is predominantly the reason that I refused to get into the real specifics with Roll Tide on the pros and cons of both designs.  The bottom line is that an approved design is sufficient and I would buy a house adjacent to either a PWR or a BWR.
Title: Re: Best New Reactor Design
Post by: Roll Tide on Dec 17, 2006, 06:27
Excellent examination of current BWR vs. 4-loop W PWR.

Now if we could get some information that would cut through the fog in that manner comparing AP-1000 vs. ABWR vs. EPR I would really be stoked. After all, I won't leave this site for another site designed by someone wearing bell bottoms...
Title: Re: Best New Reactor Design
Post by: M1Ark on Dec 17, 2006, 07:15
Excellent examination of current BWR vs. 4-loop W PWR.

Now if we could get some information that would cut through the fog in that manner comparing AP-1000 vs. ABWR vs. EPR I would really be stoked. After all, I won't leave this site for another site designed by someone wearing bell bottoms...

LOL.  I wish I could offer insight on the three competing design.  I do not have credible knowledge on those designs besides what I've gathered from google.com as compared to knowledge I have of current designs.  Any design engineers on nukeworker.com care to weigh in?
Title: Re: Best New Reactor Design
Post by: wlrun3@aol.com on Dec 17, 2006, 09:30
   "Initially it was believed, due to the possibility of clad burnout, that water could not be permitted to boil in a reactor vessel...the boiling water reactor designs provide a system that produces reactivity changes varying inversely as a function of steam void content in the core. This provides the inherent safety feature of these systems. That is, a transient power increase will produce more steam voids, reducing reactivity, which reduces power and thus limits the excursion."     Light Water Reactor Systems Training Material, Bartlett Nuclear Inc.

   From a licensed reactor operator's perspective, is there an inherently superior light water design.
Title: Re: Best New Reactor Design
Post by: Fermi2 on Dec 18, 2006, 05:41
   "Initially it was believed, due to the possibility of clad burnout, that water could not be permitted to boil in a reactor vessel...the boiling water reactor designs provide a system that produces reactivity changes varying inversely as a function of steam void content in the core. This provides the inherent safety feature of these systems. That is, a transient power increase will produce more steam voids, reducing reactivity, which reduces power and thus limits the excursion."     Light Water Reactor Systems Training Material, Bartlett Nuclear Inc.

   From a licensed reactor operator's perspective, is there an inherently superior light water design.


No not really.


Mike
Title: Re: Best New Reactor Design
Post by: thenuttyneutron on Dec 19, 2006, 12:06
I have only worked at a PWR and only know "theory" for how a BWR works.  In layman terms this means I know nothing about the BWR  ;)  I hope that we choose 2-3 designs and focus on making them standard.  I don't want to see a repeat of the last build out.  We can't afford to have "new" designs on every plant and basically run an experiment every time a new plant is built.  Deregulation will be more punitive than the regulated industry of the past.

Is it possible that we can get both a PWR and BWR design standardized and build lots of them?
Title: Re: Best New Reactor Design
Post by: alphadude on Dec 19, 2006, 09:36
you must remember the original ideas behind the current reactor designs- boilers were base load systems to be situated near large cities and be kept on line. PWRs were the hot rods (B&W expecially) that were load followers- quick to change power levels.  The integrator controls systems were originally designed to be operated by  a dispatcher from some office located elsewhere.
Title: Re: Best New Reactor Design
Post by: wlrun3@aol.com on Dec 19, 2006, 12:27
you must remember the original ideas behind the current reactor designs- boilers were base load systems to be situated near large cities and be kept on line. PWRs were the hot rods (B&W expecially) that were load followers- quick to change power levels.

    does this dynamic aspect of pwr design intention favor its selection in the current new reactor design/construction environment...
Title: Re: Best New Reactor Design
Post by: Fermi2 on Dec 19, 2006, 02:38
you must remember the original ideas behind the current reactor designs- boilers were base load systems to be situated near large cities and be kept on line. PWRs were the hot rods (B&W expecially) that were load followers- quick to change power levels.  The integrator controls systems were originally designed to be operated by  a dispatcher from some office located elsewhere.


HUH? Its much easier to follow load in a BWR than a PWR, in fact if you read the Grid Analysis of some of the utilities that invested big into BWRs they chose the design for that very reason. You can load follow a BWR down to about 55% power using nothing but flow control. Its not that easy with any PWR and never really was.

Mike
Title: Re: Best New Reactor Design
Post by: alphadude on Dec 19, 2006, 03:22
How many subs have boilers-duh- The boilers and the PWRS completed the demand cycle of the then unstable grid. You may be too young to remember but back in the 60s and 70s the grid was not stable nor did it exist- as today.

So dont confuse what happens now with the original sales pitch we got from vendors in the 70s. Boilers were the "tea kettle" of power plants -set them up around cities and run them cheap and use them for base load- Cities had a stable system of power-not usually connected to a national grid (it didnt exist)

PWR (B&W) mainly were load followers and provided high efficiency, fast response, more power per smaller site etc-(sales pitch)For example, the B&W design was extremely responsive (called the corvette of power plants by salesmen) but the grid and other situations negated the very efficient design of B&W. Superheat and economizer regions- no other like it. The ICS was set up to load following.  The dispatcher would take control of the ICS not the senior reactor operator. So the dispatcher would change reactor power levels.

The Westinghouse design was put on the market to provide a base load unit to compete with the boiler base load market. 

PWR- its all about load following and eff.
Title: Re: Best New Reactor Design
Post by: thenuttyneutron on Dec 19, 2006, 04:26
In theory I know PWR is about 1% more efficient than a BWR.  Is this true in practice?  I paid to have things taught to me that turned out to be untrue.  I was always taught in school that superheated steam was not possible with nuclear reactors.  It was not until I got in the industry that I learned the way things really work.  While OTSG are not common, they do give a nice 50 degree F or more superheat.

I like the idea of the ICS, you have to watch the power though and adjust the ULD a few times a shift.  It can be simple things like a temperature change outside that causes it.  I have heard other plants are not as easy to move around.

I don't like the fact that 3 major events in the industry occured at B&W reactors.  I want reactors so safe that the human factor is engineered out of the reactor safety.
Title: Re: Best New Reactor Design
Post by: Fermi2 on Dec 19, 2006, 05:28
I actually read the FSAR for Fermi and a bunch of other plants. Utilities that bought them did so with the intent of load following. I licensed at a BWR and I'm currently licensing at a PWR, I KNOW which is the better load follower and I'll stack a BWR 4 against any reactor in the world when it comes to following load.

As for efficency, I think it's a wash. B=W plants paid for the 1% with a MUCH smaller PZR and SG Water Volume so they don't respond well to transients. I think overall there's no real difference in the efficency between types except as designated by local preference. By that I mean Sequoyah is a VERY efficient plant. It reovers about every bit of waste heat that it can and it has 7 stages of feedwater heating, something that is very rare.

Mike
Title: Re: Best New Reactor Design
Post by: wlrun3@aol.com on Dec 19, 2006, 08:01
   do frequent power level changes significantly impact maintenance costs...which design is superior in this respect...
Title: Re: Best New Reactor Design
Post by: Fermi2 on Dec 19, 2006, 10:46
Frequent power level changes impact Operating Costs not so much maintenance costs, a BIG reason all reactors are base load machines is the higher their capacity factor the less overall cost. From a maintenance perspective online maintenance on the Secondary/BOP side is easier in a PWR  simply because the equipment is accessible we do stuff at a PWR at power that we couldn't do at a BWR simply due to dose.

During an outage it's a wash. What surprised me is the Dose at a PWR. Coming from a very low dose BWR I've found PWR doserates to be incredible

Mike
Title: Re: Best New Reactor Design
Post by: M1Ark on Dec 19, 2006, 11:29
you must remember the original ideas behind the current reactor designs- boilers were base load systems to be situated near large cities and be kept on line. PWRs were the hot rods (B&W expecially) that were load followers- quick to change power levels.  The integrator controls systems were originally designed to be operated by  a dispatcher from some office located elsewhere.

If you "knew" how fast a BWR can change power you wouldn't call a B&W or any PWR for that matter a hot-rod.
Title: Re: Best New Reactor Design
Post by: Roll Tide on Dec 20, 2006, 09:22
I don't like the fact that 3 major events in the industry occured at B&W reactors.  I want reactors so safe that the human factor is engineered out of the reactor safety.

Human factors cannot be engineered out of reactor safety. Human incompetence is one of the difficulties that must be overcome. Look closer at the TMI event, and you will see humans making the situation worse. Look closer at Davis-Besse, and you have humans making poor decisions (utility and NRC).

People make mistakes. The solution must prevent those mistakes from causing a tragedy.
Title: Re: Best New Reactor Design
Post by: alphadude on Dec 20, 2006, 10:28
-Dont get yer panties in a wad-im not calling anything anything- I just happen to be old enough to remember the sales pitch that was given to us while in ops in the early 70's . Personnally all the present plants operating are primative as hell- designed in the 50's and 60's, worked like a rented mule-and required hundreds more people than originally designed for. I remember when we pulled the drinking water fountains out of some containments because the newly created NRC didnt like that idea, and when we hired more than the 80 people projected to operate the plant- Not to mention Dixie Lee Ray! 

So I was just commenting- I never discussed the one situation where the president of the utility stood in front of the room and said " In about 20 years we will take this small device about the size of a coffee cup and put it in a unit in our back yard and get all the power we need from it."  We shook our heads and said, " Wow I cant wait until 1992!"

As as Roll Tide said in brief- "if designed by humans-humans can break it!"  The commercial factors will always come into play when purchasing an engineered item. Which are
1. Cost benefits analysis
2. Competition in the free market
3. We only know what we know-
4. Humans build it-humans can break it.


Title: Re: Best New Reactor Design
Post by: rlbinc on Dec 20, 2006, 03:43
I have worked at both BWRs and PWRs. In my 30+ years of experience, I have come to believe that BWRs are safer than PWRs for the following reasons:

1. No reliance on Boric Acid concentration to maintain Shutdown Margin. PWRs require varying Boron concentrations in the RCS to maintain SDM. Unfortunately, item 2 below poses a considerable threat.
2. PWRs have Steam Generators. A leak can allow radionuclides access to the steam system - which really doesn't bother me. The same tube leak allows unborated water access to the reactor with flaw #1 - which really does bother me.

Just the humble opinion of an old and condescending operator.
 
Title: Re: Best New Reactor Design
Post by: wlrun3@aol.com on Dec 20, 2006, 04:33
   so in the case of a tube rupture it is possible for the pressure in the secondary side to exceed that in the primary and allow secondary water into the primary system?
Title: Re: Best New Reactor Design
Post by: wlrun3@aol.com on Dec 20, 2006, 05:10
   having personally been involved in the reintroduction of the hot midloop evolution...does this present a concern, to the those involved in this thread, in same manner that a concern for non borated water introduction into the primary was recently voiced?
Title: Re: Best New Reactor Design
Post by: thenuttyneutron on Dec 20, 2006, 05:11
Human factors cannot be engineered out of reactor safety. Human incompetence is one of the difficulties that must be overcome. Look closer at the TMI event, and you will see humans making the situation worse. Look closer at Davis-Besse, and you have humans making poor decisions (utility and NRC).

People make mistakes. The solution must prevent those mistakes from causing a tragedy.

I disagree with not being able to engineer humans out of reactor safety.  The Generation 4 reactors very safe.  In the worst case accident conditions, the fuel will never melt.  The melt temperature of the ceramic fuel is higher than the highest temperature achievable.  Even with no control rods used, the negative temperature reactivity coefficient will shut the reactor down.  The temperature will stay high enough to prevent a restart but cool enough to avoid fuel damage.
Title: Re: Best New Reactor Design
Post by: Roll Tide on Dec 20, 2006, 05:45
I am glad the Gen IV reactors will be safer.

Perhaps you are not familiar with the term, "Sailor-proof". One of my first instructors in the Navy used to say, "There's nothing Sailor-proof except a cement park bench." Then one day as he was walking through the base, he saw a maintenance crew lifting a replacement cement park bench into place. Reason? Some Sailor broke it!
 8) 8)

Passive safety systems are great. How long until someone gets a "bright idea" that defeats those systems? Training and operations must never make the assumption that humans have been engineered out of safety. Operators will still be the first line of defense.
Title: Re: Best New Reactor Design
Post by: ChiefRocscooter on Dec 20, 2006, 06:10
I am glad the Gen IV reactors will be safer.

Perhaps you are not familiar with the term, "Sailor-proof". One of my first instructors in the Navy used to say, "There's nothing Sailor-proof except a cement park bench." Then one day as he was walking through the base, he saw a maintenance crew lifting a replacement cement park bench into place. Reason? Some Sailor broke it!
 8) 8)

Passive safety systems are great. How long until someone gets a "bright idea" that defeats those systems? Training and operations must never make the assumption that humans have been engineered out of safety. Operators will still be the first line of defense.

AAH yes, quite the delimia.  I think I will have to go with Tide on this one! (and that is always hard for a FL boy who tends to pefer Gator to Elephant, but that is another topic ;))  Nutty I think you are misunderestimating the lengths to which some operators will go to prove thier stupidity!  What may seem absolutly like a stupid idea can appear to some "cool way to maje it better" to a operator of questionable intellegence.
Perhaps it would be better if we could build a common sense detector and install it at entrance to plant we might be able to engineering out the worst human elements but I fear even then a few will slip through on the "OOPS factor"
Rob
Title: Re: Best New Reactor Design
Post by: Charles U Farley on Dec 20, 2006, 06:43
Interesting.  Adm. Donald just stopped by work a little while ago.  Altough I declined the invitation to attend the all hands Admiral call, I am told one of his concerns was the sense of complacency operators get with respect to the rising capabilities of technology.  I mean, c'mon, why worry when you are always a scram or F.I. away from safety, right?
Title: Re: Best New Reactor Design
Post by: thenuttyneutron on Dec 20, 2006, 07:17
Operators are rude/crude and socially unacceptable.  I know all too well what operators can/will do because you tell them "you can't".  That operator will go to great effort to prove you wrong.  One of the hardest things for me to do was to kill the engineer in me and learn to be an operator.  I have seen many weird/crazy things as an operator.  I have never seen sabotage or malicious compliance that could endanger plant equipment, compliance of standing orders that results in an inconvenience for a SRO is all fair game ;)  Some of the experiments run for the development of the Gen 4 reactors show good results.  I don't know if it took into account intentional sabotage.  I was taught many things in school that turned out to be untrue because ot "special cases".

I want reactors so safe that the worst case accident/ best attempt at sabotage only results in a minor problem that won't result in core damage.
Title: Re: Best New Reactor Design
Post by: Fermi2 on Dec 20, 2006, 08:16
Interesting.  Adm. Donald just stopped by work a little while ago.  Altough I declined the invitation to attend the all hands Admiral call, I am told one of his concerns was the sense of complacency operators get with respect to the rising capabilities of technology.  I mean, c'mon, why worry when you are always a scram or F.I. away from safety, right?


TMI happened AFTER the plant was Shutdown, Chernobyl, during the shutdown, Winksdale AFTER the SD.

Mike
Title: Re: Best New Reactor Design
Post by: Charles U Farley on Dec 20, 2006, 09:43

TMI happened AFTEr the plant was Shutdown, Chernobyl, during the shutdown, Wincsdale AFTER the SD.

Mike

Oh, we're both on the same page.  But, I look around at work an start to wonder :-\
Title: Re: Best New Reactor Design
Post by: Roll Tide on Dec 21, 2006, 08:16

I want reactors so safe that the worst case accident/ best attempt at sabotage only results in a minor problem that won't result in core damage.

Many of the best laid plans of yesterday have become the obstacles we work around today. PWR example: loops tap off only slightly below the head, and RHR (cooldown) taps off the RCS loops. These taps are below the S/G's. The industry result: we drop level to mid-loop (only half-full in the RCS) in order to install the head after refueling. To minimize the air in the U-tubes, we then place the RCS under 24" Hg vacuum prior to filling. What is the highest risk / lowest safety margin in the cycle? Vacuum fill. Certainly not sabotage, but an example where a "good design idea" is also a challenge to get around.

Complacency is the enemy.
Title: Re: Best New Reactor Design
Post by: rlbinc on Dec 29, 2006, 02:36
   so in the case of a tube rupture it is possible for the pressure in the secondary side to exceed that in the primary and allow secondary water into the primary system?

Yes, it's mentioned in the TS Bases for Boric Acid concentration in the RWST used during Safety Injection. Safety Injection Systems can fail - the RCS will depressurize through the leak. When the SG PORV finally closes, equalization will commence, then dilution can start.

Boilers are better because they shutdown on rods. Just my opinion. 
Title: Re: Best New Reactor Design
Post by: wlrun3@aol.com on Dec 29, 2006, 03:53
Yes, it's mentioned in the TS Bases for Boric Acid concentration in the RWST used during Safety Injection. Safety Injection Systems can fail - the RCS will depressurize through the leak. When the SG PORV finally closes, equalization will commence, then dilution can start.

Boilers are better because they shutdown on rods. Just my opinion. 

   ...could you keep the secondary pressure well below that of the primary by venting the secondary...

 
Title: Re: Best New Reactor Design
Post by: Fermi2 on Dec 29, 2006, 09:01
   ...could you keep the secondary pressure well below that of the primary by venting the secondary...

 


No that's not what the WOG Say. You Cool down the intact SG until the Primary and Secondary Pressures in the ruptured SG are roughly equal. Then you fill the ruptured SG  a certain level and let it bleed to the Primary.

Dilution does occur. At this point of the game you're not taking suction from the RWST. You basically fill the VCT to a certain concentration then try to use it to maintain primary boron concentration.

Mike

Title: Re: Best New Reactor Design
Post by: wlrun3@aol.com on Dec 30, 2006, 11:31
   "Shippingport and the 1953 National Security Council decision that brought it about were the first major steps towards nuclear power in the United States. But it is worth remembering that Shippingport was not the result of a stupendous technical breakthrough nor of a willingness on private industry’s part to take a risk, but a national security decision to reassert American atomic superiority during the Cold War. In their hurry to get a reactor, any reactor, pumping out electricity, the government's atomic bureaucrats seized upon the handiest reactor design available, Rickover's light water reactor. Their choice gave the light water model a head start and momentum that others were never able to match and led the industry to base its commercial future on a reactor design that some experts have subsequently suggested was economically and technically inferior."   Nuclear Inc., Mark Hertsgaard
Title: Re: Best New Reactor Design
Post by: rlbinc on Dec 30, 2006, 05:04
I was a big fan of the Shippingport Light Water Breeder Core. They used Thorium and U-233 and used neutron flux to create U-234 and U-235. The reactor operated throughout the demonstration period with a 1.01 conversion ratio. That means they created 1% more new fuel than they burned. This reactor did not need refueling. That's the type of nuclear power Admiral Rickover envisioned for the commercial industry. Not once through to the spent fuel pool.

This reactor required all of the separated U-233 in the known civilized world at the time, which made its core prohibitively expensive. Th-232 goes to U-233, so it would have been less expensive and less of a burden in following cores.

Had Admiral Rickover gained control of the civilian nuclear industry, as he requested following TMI, we would have seen this core again.


 
Title: Re: Best New Reactor Design
Post by: wlrun3@aol.com on Dec 30, 2006, 07:07
   " In the fall of 1951 Rickover faced an AEC bureaucracy that was unenthusiastic about his new idea to develop nuclear reactors for aircraft carriers...It had not taken Rickover long to choose the design for his carrier reactor: the light water design had been his favorite since the nuclear submarine project, and by applying it to the carrier, he could save both time and money. In another carry-over from the submarine work, Rickover selected Westinghouse as his main contractor...It  was precisely the light water design's power applications that led the AEC to decide simply to arrange to reorient Rickover's carrier project to produce a commercial rather than a naval reactor."    Nuclear Inc., Mark Hertsgaard

   
Title: Re: Best New Reactor Design
Post by: thenuttyneutron on Dec 31, 2006, 01:03
I was a big fan of the Shippingport Light Water Breeder Core. They used Thorium and U-233 and used neutron flux to create U-234 and U-235. The reactor operated throughout the demonstration period with a 1.01 conversion ratio. That means they created 1% more new fuel than they burned. This reactor did not need refueling. That's the type of nuclear power Admiral Rickover envisioned for the commercial industry. Not once through to the spent fuel pool.

This reactor required all of the separated U-233 in the known civilized world at the time, which made its core prohibitively expensive. Th-232 goes to U-233, so it would have been less expensive and less of a burden in following cores.

Had Admiral Rickover gained control of the civilian nuclear industry, as he requested following TMI, we would have seen this core again.


 

I agree all the way that a Th232/U235/U233 fuel cycle would be great for the United States of America .  We must also undo what Carter did in regards to fuel reprocessing.  If we breed U233 fuel from Th232 using thermal breeders, we will extend our fuel supplies by leaps and bounds.  I also support the fast breeder reactors using U238 to make Pu239.  With the right engineering we can make these newly created fuels very difficult to use for purposes other than power production.  India has large supplies of Th232 and would make a great supplier of this fertile substance.
Title: Re: Best New Reactor Design
Post by: wlrun3@aol.com on Feb 28, 2007, 08:58

   ...in response to a question from a member of the public...

   ...what is the single most attractive feature of a bwr compared to a pwr...

Title: Re: Best New Reactor Design
Post by: Fermi2 on Feb 28, 2007, 12:55
Easier to Maneuver, also post Shutdown, Shutdown margin is never a problem.

Mike
Title: Re: Best New Reactor Design
Post by: wlrun3@aol.com on Feb 28, 2007, 04:30
Easier to Maneuver, also post Shutdown, Shutdown margin is never a problem.

Mike

   ...in response to the mentioned member of the public, would "easier to operate" be equivalent to "easier to maneuver"...




   
Title: Re: Best New Reactor Design
Post by: Fermi2 on Feb 28, 2007, 04:43
No
Title: Re: Best New Reactor Design
Post by: M1Ark on Feb 28, 2007, 11:23
GE made the BWR easier to maneuver by making it an extremely complex machine.  They can shed 30% Reactor Power in seconds.  Translation= things happen really fast which does not = easier.   
Title: Re: Best New Reactor Design
Post by: Fermi2 on Mar 01, 2007, 02:13
I'm not sure about CE Reactors but a Westinghouse 4 Loop Reactor can shed about 30% load extremely fast during a runback, BUT so much active stuff happens you really have to be on your toes, Rods insert, Steam Dumps Open, Spray Valves open, the turbine sheds load and in many cases you end up Emergency Borating. The two Runbacks I had at Fermi and the time the HTR Drain Pump tripped the plant ran back, stabilized and that was that.

On the OTHER hand, The ECCS was complicated as heck and was required in about every mode. One thing I like about PWR Tech Specs, once the plant is cold about all your major Tech Specs are non applicable.

Mike
Title: Re: Best New Reactor Design
Post by: Roll Tide on Mar 01, 2007, 06:56
The ECCS was complicated as heck and was required in about every mode. One thing I like about PWR Tech Specs, once the plant is cold about all your major Tech Specs are non applicable.

That is because Boiling is good. And you can't trust gravity. (And M1 didn't think I could figure out BWRs!)  ::)
Title: Re: Best New Reactor Design
Post by: M1Ark on Mar 01, 2007, 09:17
That is because Boiling is good. And you can't trust gravity. (And M1 didn't think I could figure out BWRs!)  ::)

LOL...  Roll Tide you could absolutely figure out BWR's. I just wasn't good enough to really explain it to you.
Title: Re: Best New Reactor Design
Post by: Fermi2 on Mar 02, 2007, 02:50
Boiling in some places in a PWR is a good thing, so long as it's on the correct side of the tubes!

Gravity might work in a PWR but at a BWR I never had to wok about rods moving on instrument failures, unless of course I had enough to cause a Reactor Trip (or SCRAM as they used on the other side of the force).

Also, BORON is a GOOD thing!! Well sort of!

One thing that was a real eye opener to me is having to know when the last time you placed a Charging pump in service was, or what the plant conditions were the last time you took a demin out of service as if you just swap equipment around without thinking these things through you might find you've changed power and caused a Reactivity Event.

I happen to like the change to learn a different technology and I like both Reactor Types. They each have their idiosnycrasies , good points and bad points. I know on both Reactors I've worked at I've said I wonder WHY the HECK they did it THAT way but that's the fun part.


Mike
Title: Re: Best New Reactor Design
Post by: rlbinc on Apr 18, 2007, 01:50


Also, BORON is a GOOD thing!! Well sort of!

One more "hole in the head ala Davis Besse" and we'll be posting on "exNukeworker.com"
Title: Re: Best New Reactor Design
Post by: LaFeet on Apr 20, 2007, 01:34
I can recall one design where we could say that there is no decay heat after 10 days of shutdown.... that made all the number crunchers go bezerk.

It seems the simplest designs are the safest.  Fewer bends, single or double pass, isolation valves and some sort of reliable emergency cooling.  I dont know.... aren't we just boiling water???   And why all the tritium scare...heck... it's just tritium.  Think I'll have another beer. ???
Title: Re: Best New Reactor Design
Post by: Marlin on Apr 20, 2007, 03:50
The Pebble Bed reactor made a big splash for a while and South Africa at one time intended to build one. Lately there has not been much noise about it, has it gone by the wayside?
Title: Re: Best New Reactor Design
Post by: rlbinc on Apr 20, 2007, 09:15
I heard that the PBMR needs magnetic bearings which have not been completely developed. The turbine runs at a few thousand degrees, so oil bearings won't work.

I think graphite can be trusted in a Helium environment. I like the continuous fuel feed and reload. I like the efficiency numbers.
I also think the small scale (110 Mwe)  is more suited to sparsely loaded African continent than here in the US. www.pbmr.co.za (http://www.pbmr.co.za)
Title: Re: Best New Reactor Design
Post by: deaztrailnutz on May 05, 2007, 04:31
The Pebble Bed reactor made a big splash for a while and South Africa at one time intended to build one. Lately there has not been much noise about it, has it gone by the wayside?
Does anyone know anything about the new General Atomics designs?  I know the last plant GA built in Colorado was a bust, but on paper their new designs look good http://gt-mhr.ga.com/.   


ALSO

I have a question for M1RK, Broadzilla and the other BWR gurus; what were the major design differences between the Allis-Chalmers & GE BWR?  Did the Allis-Chalmers design use a drywell & torus for primary containment too?
Title: Re: Best New Reactor Design
Post by: Fermi2 on May 05, 2007, 05:15
Allis And Chambers used a dedicated steam drum. All the first generation BWRs used Smaller versions of PWR Containments. When GE started to build them bigger they had to go to the Pressure Suppression type containment otherwise the containment would have had to be 8 times larger than a similar PWR Containment. Given a PWR containment is about 2.5 to 3.0 Million Cubic feet...

The PWR world went with the large freestanding containments AND the infamous Ice Condenser. I'm STILL shaking my head on how they came up with that solution. I work at an Ice Condenser Plant.

Mike
Title: Re: Best New Reactor Design
Post by: Mike McFarlin on May 05, 2007, 05:55
Mitsubishi new design is noteworthy. Comanche Peak is buying? 2 of them.
Title: Re: Best New Reactor Design
Post by: Fermi2 on May 05, 2007, 05:58
Mitsubishi new design is noteworthy. Comanche Peak is buying? 2 of them.

Maybe, the NRC hasn't certified the design yet and say it won't be for quite some time.

Mike
Title: Re: Best New Reactor Design
Post by: deaztrailnutz on May 05, 2007, 07:39
Allis And Chambers used a dedicated steam drum. All the first generation BWRs used Smaller versions of PWR Containments. When GE started to build them bigger they had to go to the Pressure Suppression type containment otherwise the containment would have had to be 8 times larger than a similar PWR Containment. Given a PWR containment is about 2.5 to 3.0 Million Cubic feet...

The PWR world went with the large freestanding containments AND the infamous Ice Condenser. I'm STILL shaking my head on how they came up with that solution. I work at an Ice Condenser Plant.

Mike
How does an ice condenser work?  I hear alot of bruh-ha-ha over them
Title: Re: Best New Reactor Design
Post by: Marlin on May 06, 2007, 12:04
Containments have to contain a projected pressure surge from steam release in an accident this can be done through the volume of the containment. The volume can be reduced by operating in a subatmospheric pressure or by using a heat sink to condense the steam. The ice condensor is essentially a compartment isolated from the rest of the volume of the containment that is inside the pressure vessel with blowout panels to allow stem to enter the chamber full of crushed ice during an accident.
Title: Re: Best New Reactor Design
Post by: Fermi2 on May 06, 2007, 07:59
If y'all want a slightly more detailed version I'd be happy to provide it without a huge amount of Technospeak. The one thing Marlin said, about it being crushed ice is true and makes sense but when I first saw it I was amazed. I initially thought Ice Condensers were huge blocks of ice.

Mike
Title: Re: Best New Reactor Design
Post by: deaztrailnutz on May 06, 2007, 10:52
How much ice is required for plants like McGuire or Cook?  How is the ice maintained & stored?
Title: Re: Best New Reactor Design
Post by: Limited Quanity on May 07, 2007, 06:09
If y'all want a slightly more detailed version I'd be happy to provide it without a huge amount of Technospeak. The one thing Marlin said, about it being crushed ice is true and makes sense but when I first saw it I was amazed. I initially thought Ice Condensers were huge blocks of ice.

Mike

Hey ain't nothing like walking into a 15 deg F freezer, spending 15 min. (shiver)  :D walking on top of >2.4 million lbs of ice for a survey, checking doors, or AHU's, and then walking back into the real world at 90+ deg.  Takes a few minutes for your safety glasses to unfog, huh!  Gotta be careful!
Title: Re: Best New Reactor Design
Post by: Roll Tide on May 07, 2007, 07:05
How does an ice condenser work?  I hear alot of bruh-ha-ha over them

Wouldn't this be "off-topic" for "Best New Reactor Designs"? Not to be a stickler here, but ice condensers have less future than Edsels...
Title: Re: Best New Reactor Design
Post by: Fermi2 on May 07, 2007, 07:59
Wouldn't this be "off-topic" for "Best New Reactor Designs"? Not to be a stickler here, but ice condensers have less future than Edsels...


TECHNICALLY Ice Condensers have a brighter future at least near term than any new type of containment. I dare say the next nuke licensed in this country will be an Ice Condenser Plant. Just a hunch though.

Mike
Title: Re: Best New Reactor Design
Post by: RDTroja on May 07, 2007, 08:48
The PWR world went with the large freestanding containments AND the infamous Ice Condenser. I'm STILL shaking my head on how they came up with that solution.

According to the tales of yore (many moons ago...) the ice condenser plant was developed to reduce containment volume to enable the construction of Atlantic 1 & 2 which were designed to float... yes, I said float. They were envisioned to be able to respond to power shoratges up and down the Atlantic coast and 'plug in' to any city that needed the power. Gotta love the ideas that people came up with.
Title: Re: Best New Reactor Design
Post by: Roll Tide on May 07, 2007, 09:29
yes, I said float. They were envisioned to be able to respond to power shoratges up and down the Atlantic coast and 'plug in' to any city that needed the power. Gotta love the ideas that people came up with.

Guess that explains the current emphasis on "fitness for duty". Definitely a smokey haze in that room...  ;D
Title: Re: Best New Reactor Design
Post by: Limited Quanity on May 07, 2007, 08:05

TECHNICALLY Ice Condensers have a brighter future at least near term than any new type of containment. I dare say the next nuke licensed in this country will be an Ice Condenser Plant. Just a hunch though.

Mike

I say we're just waiting on the new checkbook to come in starting this next fiscal year.  Just told the $20 mil. is just about gone.  Most walkdown personnel and support groups will be gone at the end of the month.  Then we sit and wait....
Title: Re: Best New Reactor Design
Post by: Nuclear NASCAR on May 07, 2007, 10:04

TECHNICALLY Ice Condensers have a brighter future at least near term than any new type of containment. I dare say the next nuke licensed in this country will be an Ice Condenser Plant. Just a hunch though.

Mike

So Watts Bar is an ice condenser plant, huh?
Title: Re: Best New Reactor Design
Post by: Fermi2 on May 07, 2007, 10:30
So are Sequoyah, McGuire and Catawba.

Mike
Title: Re: Best New Reactor Design
Post by: Limited Quanity on May 07, 2007, 11:07
So are Sequoyah, McGuire and Catawba.

Mike

So is DC Cook.
Title: Re: Best New Reactor Design
Post by: Fermi2 on May 07, 2007, 11:10
Yeah DC Cook was almost the death of Ice Plants everywhere!

Mike
Title: Re: Best New Reactor Design
Post by: Roll Tide on May 09, 2007, 08:33
So Watts Bar is an ice condenser plant, huh?

My bet is that WBN2 is the last of the breed. Talk about penny-wise and pound foolish. Tons of money for ice for the life of the plant versus constructing a larger containment initially.
Title: Re: Best New Reactor Design
Post by: OldHP on May 11, 2007, 12:44
The ICC was conceived of for Atlantic 1 & 2 which were floaters - but not mobile, i.e., plug into any city (that was another concept - similar to MH1A, but using the ICC).  Atlantic 1 & 2 were to be off-shore, adjacient to and accessed through the Salem Hope Creek complex, because there simply wasn't enough space to build another two units at the site. Those units went away along with Hope Creek 2.
The sales pitch concept was that after 10 yrs of operation you added water to replace the ice weight lost through sublimation.  At 20 years you refilled!
Concept Circle-Bar - Proven Wrong - as anyone familiar with the IC plants knows!  But Circle-Bar had enough marketing skill to convince land based Utilities that they would work for low profile containments that would be acceptable to the public.
If TVA decides to go forward with WB-2, then Mike is right an ICC will be the next plant to come on line.  But, as for the next generation of plants, the AP-1000 would be a safe bet since it is the only one approved right now.

Title: Re: Best New Reactor Design
Post by: RDTroja on May 14, 2007, 08:31
As I heard the story 100 years ago, Atlantic 1 & 2 found a home at Salem after someone ran out of good drugs long enough to figure out that the concept of moving them was absurd. Then they became 'fixed'. Artificial Island was originally designed for 12 nuclear plants and when I was first there they were still talking like they were all going to be built.
Title: Re: Best New Reactor Design
Post by: OldHP on May 17, 2007, 12:47
Correct - Except that 1 & 2 actually went the route of CPs. 3 -12 never got past the drawing board, along with Atlantic 13 - 24 and STP 3 - 8.
Title: Re: Best New Reactor Design
Post by: Smooth Operator on Apr 13, 2011, 02:14
In reference to ice condensers...

So how do you keep these large chunks of ice from melting? I am imagining some pretty robust refrigeration machines. Also, when is the ice changed out? Is this a refueling outage project or is there some sort of engineered system to allow change at power or reduced power?

Title: Re: Best New Reactor Design
Post by: Fermi2 on Apr 13, 2011, 04:11
The reactor and SG and Pzr are either inside a wall called the Polar Crane wall or are inside enclosures.

The Ice Condenser is insulated from the heat sources. It has Doors that open into the Lower Containment where the RCS and Piping is. The ice itself is in 1944 12 foot tall baskets. The baskets are lattice in construction. These baskets are stacked 4 high in a 300 degree arc inside containment. The ice itself is like a snow cone. The ice is made by Ice machines outside containment. Essentially borated water is sprayed onto a barrel and the ice is knocked off the barrel and blown via elephant trunk into the baskets. There's well over 2.5 million pounds of ice in the ice condenser. The Ice Basket area is called Lower Ice
Above the Ice Baskets are the Intermediate Doors, then a plenum then the upper doors. This area is called Upper Ice. In this area are a lot of Airhandling Units. These units have ductwork going to the bottom of lower ice. There is a Glycol System outside containment consisting of Pumps and chillers. These lower glycol temperature to about 5F, then pump the glycol to the Air handlers to keep the Ice Condenser below 27F. The optimum level is 18-20F to minimize sublimation. The Air Handlers and Chillers and pumps are Non Safety Related. Post accident the pipes penetrating containment isolate. We also keep the ice borated to 2500-2700 PPM and at a PH of about 9 to 9.5. The  borated ice is to ensure Ice melt cannot dilute water coming in via the ECCS. The PH is to scrub Iodine. Ice Plants have an Upper and Lower containment that are sealed from each other.

Below the stacks of ice baskets are flow distributors that turn the steam from a LOCA up into the Ice Condenser.
1: Loca Happens
2: Lower Ice Doors Open
3: Steam is turned upwards into the ice baskets.
4: Steam flows through Ice Baskets, blows open the Intermediate Doors (Which are directly above the baskets)
5: Upper Doors blow open whatever is left blows into upper containment. Condensed water is directed back to lower containment via pipes.
6: Ice is designed to last about 60 minutes.
7: 10 Minutes after the accident starts Containment Air Return Fans start to blow any air and non condensables back into lower containment.

In answer to your other questions:

1: No if possible we never let the Ice Condenser above 27F even in outages. (about 29 is the max I've seen during an outage)
2: During outages they weigh a sample of Ice Baskets to ensure they are within Tech Spec Values, we also take core samples and boron samples.
3: The only work online inside containment is on the Air Handling Units and inspections to ensure the doors are not iced shut.

There is also a glycol system to cool the floor of the ice condenser down so the floor doesn't buckle. DC Cooks floor buckled because they didn't pay good attention to this system.

During outages, at least at SQN the Ice Condenser is a clean area in spots. Also it's weird seeing guys going into containment in coats for Ice Condenser entries.
Title: Re: Best New Reactor Design
Post by: Smooth Operator on Apr 13, 2011, 04:30
Thanks for that knowledge.

Follow up: Is all the Ice Machine system considered Tech-Spec like an ECCS train/component? You mentioned tech spec related samples, but I was wondering if everything associated with the Ice Condenser is tech spec?

If it is, I am wondering why was the Ice Condenser design chosen over just building a bigger/thicker containment?


Edit: I re-read BZ post and see the chillers, glycol pumps and air handlers are not safety related. Does that mean they are not tech spec. If they are not safety-related, then what operation limits exist if you lose your snow cone machine?



Title: Re: Best New Reactor Design
Post by: Fermi2 on Apr 13, 2011, 04:44
The Doors, Ice, Ice Baskets, and Ice Temperature Measuring system are TS. The Glycol, AHU, Chillers, and Pumps are not.
The containment isolation valves for the glycol piping are TS.
The hatches between upper and lower containment are TS.
Containment Air Return Fans are TS
The drain between Upper Containment and lower is TS .
Upper and lower containment have different Max Temperatures and oddly a lower temperature limit too.


Simple: An effort to build a smaller containment vessel that can withstand a lower pressure. Ice Containment Design limit is 12 # ie save money
Title: Re: Best New Reactor Design
Post by: Smooth Operator on Apr 13, 2011, 04:47
I am wondering if over a 30 year license, the cost to maintain the ice condenser will be greater than the build cost of a bigger containment and its maintenence?
Title: Re: Best New Reactor Design
Post by: Fermi2 on Apr 13, 2011, 04:48
No idea! I guess someone figured it is though in truth Ice Condensers are a Pain in the butt!
Title: Re: Best New Reactor Design
Post by: RDTroja on Apr 13, 2011, 04:56
No idea! I guess someone figured it is though in truth Ice Condensers are a Pain in the butt!

I found the pain in my head, which I kept hitting on too-low hanging objects, and my back which I hurt trying st squeeze around in all the too-cramped spaces.

The whole thing was a pain in the ice.
Title: Re: Best New Reactor Design
Post by: Fermi2 on Apr 13, 2011, 05:02
I found the pain in my head, which I kept hitting on too-low hanging objects, and my back which I hurt trying st squeeze around in all the too-cramped spaces.

The whole thing was a pain in the ice.


LOL.

When you're the guy who has to evaluate the Condition reports for "We dropped this into lower ice and can't find it" or this ice basket is stuck so we're justifying weighing another, OR his ice basket is too light but the average weight of the others is higher than needed plus we believe it won't create an unanalyzed flow channel due to early melt.... well you'll know why I hate the dang thing.

Plus lets face it, usually the chillers and pumps aren't in the greatest shape and are most likely to fail in the hottest week of summer.

Cool concept though.
Title: Re: Best New Reactor Design
Post by: OldHP on Apr 13, 2011, 09:11
When you're the guy who has to evaluate the Condition reports for "We dropped this into lower ice and can't find it" or this ice basket is stuck so we're justifying weighing another, OR his ice basket is too light but the average weight of the others is higher than needed plus we believe it won't create an unanalyzed flow channel due to early melt.... well you'll know why I hate the dang thing.
Plus lets face it, usually the chillers and pumps aren't in the greatest shape and are most likely to fail in the hottest week of summer.
Cool concept though.

BTDT

The sales pitch sales pitch concept was that after 10 yrs of operation you added water to replace the ice weight lost through sublimation.  At 20 years you refilled!
Concept Circle-Bar - Proven Wrong - as anyone familiar with the IC plants knows!  But Circle-Bar had enough marketing skill to convince land based Utilities that they would work for low profile containments that would be acceptable to the public.

Every outage means IC work.

I found the pain in my head, which I kept hitting on too-low hanging objects, and my back which I hurt trying st squeeze around in all the too-cramped spaces.

The whole thing was a pain in the ice.

Pre TMI mods you could walk  like a normal person , unfortunately the folks they hired (at least for MNS & CNS had no concept of accessability.  Just over support!
Title: Re: Best New Reactor Design
Post by: GLW on Oct 09, 2012, 03:00
The Pebble Bed reactor made a big splash for a while and South Africa at one time intended to build one. Lately there has not been much noise about it, has it gone by the wayside?

Scheduled for 2013,....

New date: 2015,.....

http://nextbigfuture.com/2011/03/china-210-mwe-pebble-bed-reactor-starts.html
Title: Re: Best New Reactor Design
Post by: alasfreedom on Jan 27, 2013, 10:12
Hello All!

My first time posting.  Need help from some experts - Working on a class presentation for a Rad Protection class.  I have had the (dis)pleasure of working as an Ice Tech. @ CNS.  Want to use it as a topic for my presentation...but, don't know a lot about the technical working.  Who wants to volunteer to be a subject matter expert or point me in the direction of one said person?

Much appreciation.


Title: Re: Best New Reactor Design
Post by: HydroDave63 on Jan 27, 2013, 10:41
Hello All!

My first time posting.  Need help from some experts - Working on a class presentation for a Rad Protection class.  I have had the (dis)pleasure of working as an Ice Tech. @ CNS.  Want to use it as a topic for my presentation...but, don't know a lot about the technical working.  Who wants to volunteer to be a subject matter expert or point me in the direction of one said person?

Much appreciation.

So....

1. You don't appreciate the opportunity to work inside a nuclear power plant.

2. You didn't learn much while you were there

3. You want us to do your homework for ya.

Did I miss anything?  :P
Title: Re: Best New Reactor Design
Post by: alasfreedom on Jan 27, 2013, 10:48
Wow, Rude.

1. No, I appreciated working in a nuc power plant (am a Nuc Med tech...and going on 40...., worked upper & lower ICE just shy of three weeks back on a severely broken ankle, which contain(-s, -ed) 2 plates & 12 screws.  Not once complained about how bad my ankle hurt in steel toes in the cold conditions).

2.  Learned a lot while I was there, but was too busy working in arctic cold temps with a wet butt, hair, and fogged-up safety glasses to take notes on my wet-boronated-water-mixed-with-a-little-glycol-notebook.

3.  Not interested in a hand-out.  A hand-up or a hand would be nice.

And, YES, you missed something.  A lesson for you.  Don't make assumptions (with or without the addition of a smiley face- seems a little passive aggressive.)
Title: Re: Best New Reactor Design
Post by: GLW on Jan 28, 2013, 10:01
Wow, Rude.

Strong comeback, you'll be fine here,...

Except:


....Not once complained about how bad my ankle hurt in steel toes in the cold conditions).....


You've complained now,...

To the entire world wide web,... [coffee]
Title: Re: Best New Reactor Design
Post by: GLW on Jan 31, 2013, 09:59


I appreciate the atta' boy. 

Your welcome,...
Title: Re: Best New Reactor Design
Post by: Rennhack on Feb 08, 2013, 03:22
1. You don't appreciate the opportunity to work inside a nuclear power plant.
Wow, Rude.

Apparently Dave has never been an 'Ice Monkey', or he would have understood the Dis-Pleasure.
Title: Re: Best New Reactor Design
Post by: HydroDave63 on Feb 08, 2013, 09:41
Apparently Dave has never been an 'Ice Monkey', or he would have understood the Dis-Pleasure.

Nope.... but I did stay at a Holiday Inn Express once!  :P


(http://www.orlandosavings.com/images/holiday-express-logo.jpg)
Title: Re: Best New Reactor Design
Post by: stenlund on Feb 16, 2021, 05:57
BWR/5 pump trip from about 95% power/87% core flow. That would be the core flow at the end of the transient? Will an automatic SRI follow?