Nuclear Plant Taken Down In Anticipation of Snowstorm

mdsolar writes Pilgrim Power Plant in Plymouth was taken offline in anticipation of the weekend snowstorm. According to a statement from Entergy, the owner of Pilgrim, the plant was taken off line in preparation of "a potential loss of offsite power or the grid's inability to accept the power Pilgrim generates." This is the second time this season the plant has been shut down due to storm conditions. On January 27 the facility was taken offline after the two main power transmission lines were knocked out by blizzard conditions. Although the transmission lines were restored within a few days, the plant remained offline until February 7 at which time it was reconnected to the grid.

Comments

A precaution when done ahead of time.

[Anonymous Coward]

An emergency measure when done after the fact.

Re:A precaution when done ahead of time.

[Mr D from 63]

The plant will be shut down in anticipation that the transmission grid will suffer problems and not be able to take the power. It has nothing to do with the plant itself or inability to run through the storm. Plants all over the northeast have kept the lights on for millions throughout that rash of harsh winter weather we have been having. Pilgrim is a reliable station still going strong after many years.

Snow covered solar panels won't be very useful, that is for certain. Windmills are shut down in blizzard conditions. Thankfully other sources are available.

Re:A precaution when done ahead of time.

[Rei]

"Potential loss of offsite power" was listed as one of the two reasons for taking it down; the inability of the grid to accept power is only one. I would presume based on this that offsite power is part of their scenario for dealing with emergencies wherein the plant can no longer supply power for cooling its reactor, and hence the risk of loss of offsite power means an unacceptable meltdown risk should a disaster occur at the plant in the coming days.

Re:A precaution when done ahead of time.

[Mr D from 63]

True.

Loss of offsite power is an analyzed condition and the plant's license requires it to shut down when offsite power is lost. The safety analysis shows that the plant is in a higher risk level as it becomes reliant on its emergency diesels should another severe accident occur at that time. (Even though in those situations, the plant is designed to still be able to cope with all design basis accidents)

There is no license requirement to shut down in anticipation of a loss of offsite power, and the plant is designed to handle it safely.

Plants keep running through major storms all the time. This is particular to the local grid.

Re:A precaution when done ahead of time.

[TubeSteak]

Pilgrim is a reliable station still going strong after many years.

Lol @ reliable. Pilgrim has been on the NRC's worst-ten shit list for a few years now.

The same day the storm hit, the NRC sent Pilgrim a letter.
http://pbadupws.nrc.gov/docs/ML1502/ML15026A069.pdf

Overall, the NRC has determined that your act ions have not provided the assurance level to fully meet all of the inspection objectives and have correspondingly determined that Pilgrim will remain in the Degraded Cornerstone of the Action Matrix by the assignment of two parallel White PI inspection findings. [Green, White, Yellow, Red, in increasing order of severity] [...] . Additionally, for one of the
root cause evaluations, inspectors determined that Entergy failed to investigate a deficient condition in accordance with corrective action program (CAP) requirements to ensure they fully understood all of the causes of one of the [four unplanned] scram events [that happened in 2013].

Reliable != multiple unplanned SCRAMs per year.

Anyways, on January 27, while the reactor was SCRAMing, these three things happened:

The High Pressure Coolant Injection System had to be secured due to failure of the gland seal motor.
The station diesel air compressor failed to start.
One of the four safety relief valves could not be operated manually from the control room.

Those safety relief valves are the ones that get used to vent pressure after the coolant injection system fails.

Pilgrim has problems. On top of all those problems, locals are spitting mad because the disaster plans fail to include scenarios like "giant blizzard shuts down all the roads and nobody can evacuate."

Re:A precaution when done ahead of time.

[AmiMoJo]

Actually the earthquake damaged part of the emergency cooling system and thus prevented effective cooling that would have averted a meltdown. This did not become apparent until months after the disaster when it was possible to examine the pipes and valves that make up the system. They were pumping water in with fire engines, but it was being syphoned off by a broken valve and never made it to the reactor. Even if the valve had been okay, pipes further down were leaking anyway.

Search YouTube for NHK documentaries on the subject. NHK is like the Japanese version of the BBC, pretty reliable and they have done a lot of work examining what went wrong at Fukushima. Their documentaries are available in English.

mdsolar strikes again

[peon_a-z,A-Z,0-9$_ !]

He probably wouldn't post something about a 'renewable' going offline, based on his posting history.

Re:mdsolar strikes again

[Mr D from 63]

Nothing that mdsolar wrote was untrue, and it didn't even sound judgemental.

To be fair, the title was changed by samzenpus. mdsolar's submittal title said something like "unreliable nuclear plant shut down....". An attempt to mislead on the reason for the shutdown.

Re:mdsolar strikes again

[Tailhook]

You are attempting to discredit this story by maligning the submitter.

The story is FUD. That's mdsolar's MO; post transparently stupid, fear mongering stories about nuclear power. He deserves to be maligned; he's earned it.

Re:The U.S.A. is now a third world country

[Anonymous Coward]

If such a thing happened in Canada you can be sure we wouldn't take over a week to repair the government-owned power lines.

https://en.wikipedia.org/wiki/...

Right...

Re:Devil's advocate of the Devil's advocate?

[peon_a-z,A-Z,0-9$_ !]

However, in this case, the customers don't lose power because the generation isn't there. Customers would lose power because the grid fails. Entergy has power from other sources or purchasing agreements to make up for this temporarily.

Similarly, it is unsafe (and illegal, technically) to run your nuclear powerplant with no access to the grid. If you have a coal plant that gets disconnected from the grid, you'd shut it down too with no way to generate revenue from burning additional fuel.

Devil's advocate to your misguided devil's advocate...The problem is the electrical grid not the source.

MDSolar must be disappointed...

[dfenstrate]

...that it didn't melt down. We get it, MD, you don't like nuclear power.

Re:strange circumstance.

[peon_a-z,A-Z,0-9$_ !]

Nuclear plants of the design mentioned in the article must legally have offsite power to continue operation. As soon as offsite power is lost, the plant is required to shutdown. An emergency shutdown is more paperwork than a planned shutdown such as this.

The reason for this is that in an accident scenario, you would like to rely on offsite power to run your emergency coolant pumps for this particular design.

Newer reactor designs don't have this issue, but this is a pretty economic decision considering an emergency shutdown if/when the offsite power does eventually trip. The grid seems pretty unreliable based on past experience, as the article even notes.

Re:Nuclear plants don't like sudden shutdowns

[AK Marc]

Since you bought up Fukushima, I've long wondered how a modern first world nation-state could not manage to get generators on-site before the batteries went flat. I've read that the utility tried but could not get them there in time due to traffic jam and destroyed infrastructure on the ground. Did nobody think of picking up the phone and calling someone at the military to dispatch some bloody helicopters? I can't fathom that you need so much power to run cooling pumps as to render the required generators too heavy to fly in.

I didn't want to say, because it sounds like the "depend on the US" cliche, but I could have driven to work, chained up a generator (not sure what they needed, but I had a 40kVA that I could have sent), and driven it to a C130 (nearby military base) and gotten it on the ground in Japan well under the 12 hours battery they had (presuming the US military would give civilian aid). Then arrange some helicopter transport to the site.

My understanding is that Tepco lied to everyone. They lied about it being under control, and whether it would be "saved" and what they needed and such. An international call for generators, and I'm sure there are hundreds (or thousands) that could have come from South Korea in time, even if they couldn't find a single one in Japan. And there would have been many options to getting it there. Tanks don't mind mud so much, and you can hook a civilian trailer to one. So tow the damn thing. On the road, where you can, on the shoulder where you can, over fields and through houses where you have to. It's a fucking nuclear meltdown.

But Tepco said "it's under control". "There was an incident, but it's currently contained". At least that's how I understand it from the information I saw released. Everyone with a "C" in their job title should be in jail, or working from the reactor floor.