blackstart capability

[SloGlo]

this reeds like nukes are a valuable blackstart commoity


https://www.publicpower.org/periodical/article/study-ferc-and-nerc-finds-sufficient-blackstart-capacity

[GLW]

you may be confusing blackstarts with baseloads,...
SMR stations could be blackstarts,...
but those are not real,...
hydro is,...
now, SMRs on a current PWR/BWR nuke site?!?!?!?! maybe,...
BUT!!!, that all requires ENERGY POLICY which we we do not have on a coast to coast consistent plan,...
we have a mish mosh of moderately regulated to loosely regulated ISOs, and other initialisms where basically the market promotes a paradigm of,...
"build cheap, big output natural gas plants and burn through the natural gas commodity of this nation until it's gone lettin tomorrow figure out what to do when tomorrow comes",.....
okay, I'm done,...for now,...

[TVA]

Blackstart means available within 15 minutes without any support resources. A Combustion Turbine Generator, A large diesel ( usually locomotive type) a hydro unit.
You use a blackstart to provide electricity to a small portion of the grid in order to supply a larger unit ie a coal or natural gas plant sufficient power to to start up and restore more of the grid then work your way out.
Example at Fermi we had 4 Peakers which were Combustion Turbine Generators. #1 was the Blackstart Peaker. It was dedicated to the plant under blackstart. We would start it and use it to restore busses inside the plant. We also used it to feed power to the other Peakers auxiliary units. Then we would start an additional Peaker and use it to power the grid to the Monroe Power Plant. Monroe would start one unit then use it to expand restoration on the grid and restore a Bell River Unit and start another unit at Monroe. Then on and on.
Iirc Davis Besse used a locomotive diesel. Fermi was unique in having that specific capability onsite. Many have to rely on other resources but every utility nuclear or not has the capability

[thenuttyneutron]

Iirc Davis Besse used a locomotive diesel. Fermi was unique in having that specific capability onsite. Many have to rely on other resources but every utility nuclear or not has the capability

DB has three EMDs with a capacity of about 2.5 MW a piece.  The third EMD is their SBO.  Ignoring license requirements, there was no way that it could start up without at least one offsite power source.  DB needs to have a boiler to startup which is powered off of non-essential power and diesel oil.  The time required to restart the secondary plant would also be an issue.  The house loads alone are about 40 MWe and you could maybe cut that down by a few MW by starting up on 3 RCP and 2-3 Circ water pumps.

I could see SMRs as being blackstart capable considering the fact that Nuscale will not be required to have Class 1E electrical systems.  Assuming it has a full load reject capable secondary plant, you could keep the reactors critical and be ready to start pulling steam when the load dispatcher asks for power.

[TVA]

Blackstart isnt required to restart the plant. It’s there to stabilize the plant in event of loss of all power

[mjd]

DB has three EMDs with a capacity of about 2.5 MW a piece.  The third EMD is their SBO.  Ignoring license requirements, there was no way that it could start up without at least one offsite power source.  DB needs to have a boiler to startup which is powered off of non-essential power and diesel oil.  The time required to restart the secondary plant would also be an issue.  The house loads alone are about 40 MWe and you could maybe cut that down by a few MW by starting up on 3 RCP and 2-3 Circ water pumps.

I could see SMRs as being blackstart capable considering the fact that Nuscale will not be required to have Class 1E electrical systems.  Assuming it has a full load reject capable secondary plant, you could keep the reactors critical and be ready to start pulling steam when the load dispatcher asks for power.

Mostly true about all US PWRs. None can start up w/o off-site power and get their own T-G online to supply the grid. As you stated they need RCPs (to clear RPS Power/Flow trips and keep RCS T above min T for critical) and Circ Pumps for condenser vacuum to run the T-G. These loads come off the high V bus in the plant (13.8 or 6.9 KV) and no onsite DGs have the poop to start and run these loads, even if back-feeding the HV bus is possible.

NuScale can probably 'black start' the reactor (no RCPs, and designed to do a cold criticality and critical heat up which US PWRs can't do). NuScale has an Aux Blr and DGs on site... if that supports drawing a condenser vacuum NuScale may have complete 'blackstart' capability.

But the whole 'Black start' issue is a lot more complicated than this thread will allow for a decent discussion. The real issue, as I see it, is why do the US Plants continue to "hang on" at full power during external conditions where expected grid disturbances are likely to cause a trip on Load Rejection or LOOP? These plants are "afraid" to do a rapid down power and separate from the grid and just supply their own house power until grid conditions are stable. There is no machine more stable than a nuke running unhooked from off-site power (Don't believe it? Ask the US Navy). The loss of nukes during hurricane Sandy was down right stupid and avoidable with coordinated advance planning. And none was more stupid than the loss of Ginna, when they chose to stay at 100% as the Sandy remnant passed directly over the plant and caused a LOOP.

"One-of-these-days"... people will find out. An event that causes a long-term grid blackout and infrastructure loss will occur (stopping fuel delivery), and the only power plants with enough fuel on-site to boot the system up will be the nukes, and nobody will have a "crank" to start them. Loss prevention should be the plan... not black start.

The utility 'hang-on-at-all-costs' mentality has caused other problems.... the second time DC Cook lost both Units (and destroyed their Intake Structure Trash Removal System) because they tried to hang on with a forebay plugged with debris was stupid and avoidable with an advance plan.

[TVA]

Actually I have never worked at a plant that had a hang on at all costs mentality. I have been licensed on 3 plants and am certified on a 4th. Havent seen it once.

[TVA]

It isnt complicated.
Grid goes away
Diesels dont work
Need to remove decay heat
Blackstart something to restore power to allow removal of decay heat
Supply power to a coal or gas turbine unit or use hydro
Use that unit to buildout to restore power to the grid
Its the same thought process everywhere

[GLW]

now, SMRs on a current PWR/BWR nuke site?!?!?!?! maybe,...

The house loads alone are about 40 MWe and you could maybe cut that down by a few MW by starting up on 3 RCP and 2-3 Circ water pumps.

I could see SMRs as being blackstart capable considering the fact that Nuscale will not be required to have Class 1E electrical systems.  Assuming it has a full load reject capable secondary plant, you could keep the reactors critical and be ready to start pulling steam when the load dispatcher asks for power.

my presumption was that a SMR (maybe two) sited ON an operating and current PWR/BWR multi-unit site could provide the blackstart capability for the PWR/BWR units on that currently operating site making the full site "independent",....


as it is, there is some notion of extending operating licenses out to eighty years,...


so, with an enforced policy fomenting grid stability/redundancy above economics and markets then the above might be worthwhile,...


then again maybe not,...


first, policy would have to include re-regulating the grid, from A to Z,...

[TVA]

Somewhere over the rainbow!

I can have a gas turbine ready to accept load in less than 10 minutes. No expensive licensing and it can be lifted and set in place with a helicopter. Why would I choose any other option?

[hamsamich]

I haven't seen it either, but if Davis Besse would continually shove their reactor head issues under the bed, I'm thinking it's possible a nuke would tolerate smaller issues and try to fix them online without shutting down.  That being said I was never in the control room.  Traveling screen issues comes to mind for some reason as a stand out.  I think "hang on at  some costs" would be a better term.  Operating with any issue no matter how small will incur some minuscule amount of risk.

[TVA]

I have yet to see or hear of any reactor trying to hang on during a grid risk scenario. It simply doesnt happen.
The DB head event was not considered an overt risk type of scenario when it was happening. In retrospect sure it was. Had ANYONE ever went to DB management and said we have strong evidence there is a hole in the vessel head they would have shutdown. Anyone thinking otherwise has never operated or been in the position to make risk informed decisions.
Travelling screens is a different and more complex issue.

[hamsamich]

Yeah I was just talking about a "hang on at all costs" mentality in general.  Not strictly grid issues.

[hamsamich]

https://www.ocregister.com/2018/05/04/california-to-become-first-u-s-state-mandating-solar-on-new-homes/

maybe we should just cover all nuclear power plants with solar panels.  that will solve everything.  at least according to CA.

[GLW]

well, this thread has the potential to be one of those "Best Thread Ever!" candidates that pop up 'round these parts about every 3 years or so,.......


if the RP types would just stop typing that is,....


the operators truly have contributed the best threads ever out here in the News and Discussions forum,...

[TVA]

It’s accidental! One of the operators said it’s complex. Station Blackout isnt complex at all.

[mjd]

Yeah I was just talking about a "hang on at all costs" mentality in general.  Not strictly grid issues.

I probably wasn't specific enough when I said 'hang on at all costs mentality', because I WAS ONLY referring to during extreme weather events (specifically the last 10 year history), and other external events. I concur that is not the day-to-day attitude about resolving what might be considered gray areas in technical issues.

The Annual Unplanned Reactor Trip count is remarkably low, but of those the trip count due to severe weather induced grid problems is a significant contributor (might be the single highest contributor). Since this trip count is thought to be, by INPO, an appropriate indicator for overall plant performance evaluation, it seems appropriate this issue needs a big-picture re-look to reduce that specific trip cause.

It is related by nature to the "black start" issue and discussion, about wide area black outs especially considering potential wide area infrastructure loss. Nukes have the highest on site fuel 'storage' supply; they can last the longest without fuel delivery. But nukes can't "black start", they need off-site power to start. So saving the nukes during wide spread extreme weather, to provide the "crank" to reboot the grid seems like the best overall integrated plan. To accomplish that nuke organizations have to change their current (old) thinking about what to do with the plant during the APPROACH of these extreme weather events. That was my point, the fact they haven't means they aren't looking at the data.... or are stuck in old mentality thinking.   

[TVA]

IF you lose the grid the plant will trip. It’s a non starter

[mjd]

IF you lose the grid the plant will trip. It’s a non starter

WRONG! I'm preaching (when severe weather is forecast and imminent) reduce power to about 10%, disconnect the main generator from the grid, and run isolated supplying your own house load until the extreme weather has passed and grid is stable again. So the plant doesn't trip... but you already knew that! So what's the point of your post? This isn't rocket science... it's the config every plant is in when starting up, before the main gen is synch'd to the grid.... so all Ops is already familiar with operating in that config and it is covered by procedures already. (NOTE: this post is for everybody else).

[TVA]

Uh you are telling a former NERC Coodinator and the guy who helped redesign the SQN Offsite power supply that he is wrong on a grid issue. I know for a fact DB coolant pumps are not diesel backed and neither is her condensate fw system.
Stop babbling

[Bonds 25]

Is the electricity to run the RCPs and feed water pumps supplied by offsite power or diesels at 10% reactor power?

[tr]

Interestingly, Perry supposedly was designed to blackstart.  There are non-safety load centers off the DGs to power things like the CRD pumps, instrumentation, etc.  Thought was you could go critical, do a natural circulation heatup while feeding with RCIC, blow heat somewhere (suppression pool or steam condensing?), get up to rated, get a turbine feed pump online, roll and sync the turbine.  Once enough power was being made, start the RCPs.  Can't remember how things like condensate and circ water were.handled (if they even were).  Obviously not within the license, but interesting concept by GE.

[mjd]

Is the electricity to run the RCPs and feed water pumps supplied by offsite power or diesels at 10% reactor power?

They would be supplied (all house power can be ) by the Station Auxiliary Transformer to the house HV bus (not the EDG bus). The Aux Transformer is powered directly by the Main Generator, upstream of the generator output breakers to the grid. So you can sit powering ALL your normal house load directly from the main generator, via the Aux Transformer, with reactor power between 10-15%. Your generator output breakers to the grid are open. Thus no grid disturbance will cause a trip, because you aren't hooked to the grid. That feature (Aux Transformer off the generator) is a typical design feature. For a lot of plants it is the normal full power electrical line-up, but done at ~10% with the generator breakers to the grid open.

[Bonds 25]

That was my point. So TVA is in essence, wrong?

[hamsamich]

wait wait wait yall....TVA knows everything about every nuclear plant ever made.  Aren't they all the same?  Nobody's expertise matters but his.  Thought everybody knew that already.  Gosh!