Why borated water for PWR and not necessary for BWR

Started by hazmatguy, Apr 11, 2011, 10:46

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Cycoticpenguin

Gotta say it. PWR's just sound like a massive pain in the arse for everyone. Im glad Im now boiling the water in my core ;)

Fermi2

On the other hand:

PWRS Don't

1: Have to get to 100% then lower power to establish a 100% power rod line

2: Have to move control rods one step every week.

3: Have to downpower every quarter for rod swaps and scram time testing.

4: Scram time testing post outage takes about 3 minutes for a PWR.

5: Have to tag out about a million valves during an outage to change out control rods.

6: Don't have about 47876897 Rod Interlocks during a refueling.

7: Don't have to worry about how nasty the core reacts at the end of a long cycle to a transient.

8: Thermal limits are tons easier and don't move around based on core life.

9: PWRs can actually release decay heat OUTSIDE containment post trip with an MSIV closure.

10: Have a trillion different primary containment valve groups with a zillion different isolation signals.

11: Have a different logic system for each ECCS System to screw you over during an outage. Cold Shutdown, just inhibit the SSPS system.

12: Cold Shutdown TS requirements for ECCS.

13: And for an SRO, You're only in one EOP at once and the EOP network tells which one it is.

Cherenkov

Quote from: Broadzilla on Apr 13, 2011, 06:39
On the other hand:

PWRS Don't

1: Have to get to 100% then lower power to establish a 100% power rod line

2: Have to move control rods one step every week.

3: Have to downpower every quarter for rod swaps and scram time testing.

4: Scram time testing post outage takes about 3 minutes for a PWR.

5: Have to tag out about a million valves during an outage to change out control rods.

6: Don't have about 47876897 Rod Interlocks during a refueling.

7: Don't have to worry about how nasty the core reacts at the end of a long cycle to a transient.

8: Thermal limits are tons easier and don't move around based on core life.

9: PWRs can actually release decay heat OUTSIDE containment post trip with an MSIV closure.

10: Have a trillion different primary containment valve groups with a zillion different isolation signals.

11: Have a different logic system for each ECCS System to screw you over during an outage. Cold Shutdown, just inhibit the SSPS system.

12: Cold Shutdown TS requirements for ECCS.

13: And for an SRO, You're only in one EOP at once and the EOP network tells which one it is.

You can say that again!

-C

Cycoticpenguin

Quote from: Broadzilla on Apr 13, 2011, 06:39
On the other hand:

PWRS Don't

1: Have to get to 100% then lower power to establish a 100% power rod line

2: Have to move control rods one step every week.

3: Have to downpower every quarter for rod swaps and scram time testing.

4: Scram time testing post outage takes about 3 minutes for a PWR.

5: Have to tag out about a million valves during an outage to change out control rods.

6: Don't have about 47876897 Rod Interlocks during a refueling.

7: Don't have to worry about how nasty the core reacts at the end of a long cycle to a transient.

8: Thermal limits are tons easier and don't move around based on core life.

9: PWRs can actually release decay heat OUTSIDE containment post trip with an MSIV closure.

10: Have a trillion different primary containment valve groups with a zillion different isolation signals.

11: Have a different logic system for each ECCS System to screw you over during an outage. Cold Shutdown, just inhibit the SSPS system.

12: Cold Shutdown TS requirements for ECCS.

13: And for an SRO, You're only in one EOP at once and the EOP network tells which one it is.


Luckily for me, none of that is applicable to me for a couple years ;)

Smooth Operator


RDTroja

Quote from: Broadzilla on Apr 13, 2011, 06:39
On the other hand:

PWRS Don't

1: Have to get to 100% then lower power to establish a 100% power rod line

2: Have to move control rods one step every week.

3: Have to downpower every quarter for rod swaps and scram time testing.

4: Scram time testing post outage takes about 3 minutes for a PWR.

5: Have to tag out about a million valves during an outage to change out control rods.

6: Don't have about 47876897 Rod Interlocks during a refueling.

7: Don't have to worry about how nasty the core reacts at the end of a long cycle to a transient.

8: Thermal limits are tons easier and don't move around based on core life.

9: PWRs can actually release decay heat OUTSIDE containment post trip with an MSIV closure.

10: Have a trillion different primary containment valve groups with a zillion different isolation signals.

11: Have a different logic system for each ECCS System to screw you over during an outage. Cold Shutdown, just inhibit the SSPS system.

12: Cold Shutdown TS requirements for ECCS.

13: And for an SRO, You're only in one EOP at once and the EOP network tells which one it is.

The Turbine is not a High Rad Area at power, nobody gets an RCS shower when you change control rod drives, dose rates are lower pretty much everywhere, containments are easier to get around in than drywells (well, most of them,) no Torus or Suppression Pool...

They both have their good and bad points, but I can't remember many of the BWR good points right now.
"I won't eat anything that has intelligent life, but I'd gladly eat a network executive or a politician."

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Cycoticpenguin

Quote from: Sun Dog on Apr 13, 2011, 08:40
Flag me for piling on if you want, but....

I believe that if you asked seasoned traveling RP techs (25+ years of commercial experience) to list the 10 nastiest commercial plants they have been to, the list would be heavily weighted with boilers.  I am guessing 8 of the 10.  Keep in mind that boilers make up only 33.7% (35/104) of the commercial reactors in the US.  So, I'd say that from an RP perspective, boilers generally suck.

Of course, I may be wrong.

haha I spent 3 hours waiting after my first plant tour due to being "gassed up" :D

Quite the change from the PWR world ;)

Fermi2

I was remarking on operational aspects though I will say in the 9 10 outages I did at Fermi they had a lower overall dose than my first few outages at SQN. Though SQN finally got serious about dose tracking and figuring out where dose went and we tend to meet our dose goals nearly all the time.

Keep in mind most personnel at a BWR do not go into the high rad areas at power anymore than they do at a PWR so for an operator dose at power and during most outage areas is about the same. The nig difference during an outage Operators enter containment at a BWR 4 when at power they wouldn't, and for the most part in the areas that are easily reached in a BWR containment there are no low dose waiting areas.

Fermi2

Quote from: Charlie Murphy on Apr 13, 2011, 08:52
haha I spent 3 hours waiting after my first plant tour due to being "gassed up" :D

Quite the change from the PWR world ;)

You weren't at a big league PWR were you?

Already Gone

Quote from: RDTroja on Apr 13, 2011, 08:16
The Turbine is not a High Rad Area at power, nobody gets an RCS shower when you change control rod drives, dose rates are lower pretty much everywhere, containments are easier to get around in than drywells (well, most of them,) no Torus or Suppression Pool...

They both have their good and bad points, but I can't remember many of the BWR good points right now.

Change control rod drives in a PWR?  Doesn't happen often, does it?  I can't remember seeing it done once.  Has it been done?
And turbines being a High Rad area at power?  Hell, I've seen BWR turbines that were High Rad Areas when shut down.

But, there is no S/G eddy current testing, tube plugging, tube sleeving, sludge-lancing, chemical cleaning, or total replacement (although you have to replace steam dryers in a BWR sometimes) involving a hole in the containment.  No reactor head replacement, no need for a fuel transfer tube or upender, no seal table, no flood-drain-flood-drain pulling and setting the internals twice every refuel...

Actually, I think the topic was Boron.  So, I'll steer back that way.
Borax is cheap and plentiful.
When dissolved in water, it makes Boric Acid, which is a weak acid that is easily controlled.
When it absorbs a neutron, it breeds Lithium ions, which forms LiOH and balances the coolant pH without frequent additions. (usually you only add Lithium at startup, which is highly toxic and very expensive)
It makes it really easy to find small leaks from the coolant or cvcs or spent fuel systems.  (Just look for the white fluffy spots)
You can run it through an evaporator and recycle it.
It isn't toxic, flammable, or subject to breakdown.
It freakin' works!
"To be content with little is hard; to be content with much, impossible." - Marie von Ebner-Eschenbach

Cycoticpenguin

Quote from: Already Gone on Apr 13, 2011, 09:00
Change control rod drives in a PWR?  Doesn't happen often, does it?  I can't remember seeing it done once.  Has it been done?
And turbines being a High Rad area at power?  Hell, I've seen BWR turbines that were High Rad Areas when shut down.

But, there is no S/G eddy current testing, tube plugging, tube sleeving, sludge-lancing, chemical cleaning, or total replacement (although you have to replace steam dryers in a BWR sometimes) involving a hole in the containment.  No reactor head replacement, no need for a fuel transfer tube or upender, no seal table, no flood-drain-flood-drain pulling and setting the internals twice every refuel...

Actually, I think the topic was Boron.  So, I'll steer back that way.
Borax is cheap and plentiful.
When dissolved in water, it makes Boric Acid, which is a weak acid that is easily controlled.
When it absorbs a neutron, it breeds Lithium ions, which forms LiOH and balances the coolant pH without frequent additions. (usually you only add Lithium at startup, which is highly toxic and very expensive)
It makes it really easy to find small leaks from the coolant or cvcs or spent fuel systems.  (Just look for the white fluffy spots)
You can run it through an evaporator and recycle it.
It isn't toxic, flammable, or subject to breakdown.
It freakin' works!

Tell that to davis-besse ;)

Cherenkov

Again, Besse was a personnel and integrity failure.

-C

Cycoticpenguin

Quote from: Cherenkov on Apr 14, 2011, 08:34
Again, Besse was a personnel and integrity failure.

-C


Absolutley, but I was implying its not this miracle innoquous substance :)

Cherenkov

Quote from: Charlie Murphy on Apr 14, 2011, 09:28

Absolutley, but I was implying its not this miracle innoquous substance :)

It is pretty magical.

-C