Wednesday, July 18, 2012

"Unusual Event" at Limerick Nuclear Power Plant in Pennsylvania, US, Unit 1 Reactor Manually Scrammed

The Limerick Generating Station is operated by Exelon.

From Excelon's press release on 7/18/2012, announcing that the Unit 1 has been taken offline:

Limerick Operators Take Unit 1 Offline

Operators at Limerick Generating Station took Unit 1 offline this morning following an electrical disturbance on the non-nuclear side of the plant.

POTTSTOWN – Operators at Limerick Generating Station took Unit 1 offline this morning following an electrical disturbance on the non-nuclear side of the plant.

Unit 1 will remain offline until repairs, inspections and testing can be completed. Limerick Unit 2 continues to operate at full power.

As a result of the electrical disturbance, an Unusual Event was declared at 8:39 a.m. and terminated at 9:46 a.m. in keeping with NRC procedures. An Unusual Event is the lowest of four Nuclear Regulatory Commission emergency classifications.

Exelon Generation notified all appropriate federal, state and local government officials of the event. There is no threat to the health and safety of the public associated with this event.

Limerick Generating Station is located approximately 21 miles northwest of Philadelphia. With both units at full power, the site can produce enough carbon-free electricity for 2 million homes

An excellent example of not saying anything like "where exactly" and "what exactly".

According to reports, a transformer blew up in the turbine building. Here's from The Times Herald (7/18/2012):

‘Unusual event’ reported at Limerick power plant

(Updated at 10:55 a.m.) LIMERICK — The Nuclear Regulating Commission said it is closely monitoring events at the Limerick Generating Station after a manual scram around 8:15 a.m. shut down the reactor at the nuclear power plant.

According to NRC spokesman Neil Sheehan, an electrical fault was reported in a transformer in a turbine building that spurred the scram and that the transformer is not a main transformer.

The event was listed as an “unusual event” around 8:39 a.m., the lowest of the event ratings, Sheehan said. No one was injured in the incident and no outside help was requested, Sheehan said.

Sheehan said the transformers have been known to fail from time to time and that the reactor was safely shut down.

Sheehan said there are no complications at the power plant at this time and there is no danger to the public from the incident.


LIMERICK — An “unusual event” was reported Wednesday morning in Unit 1 of the Limerick Nuclear Generating Station.

According to Frank Custer, communications director with Montgomery County, the county received an email from Exelon, parent company of the nuclear power plant, stating that an explosion had occurred causing the “unusual event,” in Unit 1 but the event did not pose any threat to the public.

Custer said the notice reported the “unusual event” had been terminated.
A call placed to the Limerick Generating Station’s media relations spokesperson was not picked up or returned as of 11 a.m. Wednesday.


Atomfritz said...

If this streak of nuclear incidents continues, there are good chances USA will host next spectacular high INES event. Again a new event happened:

(Localized excessively high neutron fluxes can easily lead to local overheating, partial meltdowns and increasing demand for compton cameras)

Anonymous said...

The term "unusual event" has negative connotations in my book which is already heightened ever further because I live within the ten mile radius. (I was against nuclear power when Limerick was being built back in the 80's.)

Anonymous said...

It is possible that other nations possess a Stuxnet also. Who would say that this is not the case?

Anonymous said...

21 miles northwest of Philadelphia.

I would prefer looking at a skyline of wind turbines than knowing that this untamable monster was being held at bay by a corporation whose primary mission is making a profit for its owners, under the ineffective oversight of a captive regulator.

There is no future in nuclear power. Shut down this plant.

kintaman said...

Everyone get your "smiles" ready!

Anonymous said...

"transformers have been known to fail from time to time"???
When did a transformer failed last in your home? Are home appliances build better than npps?
They make it look like a minor thing but they had to take the reactor offline; how minor can that be?
Why isn't the design of these transformers improved and the faulty ones replaced *before* they explode?
What if a transformer failed and the plane you are flying on had to turn off one engine? Would you think this is a minor event?


Anonymous said...

Play this when you need to know there are a few elected officials who still do not have their face firmly stuck to the corporate nuclear arse.
Go Dennis

If you are interested, this is where you can read the daily reports with the added bonus of how medical applications can go awry.

wouldn't that be a pretty picture
turning the compton camera on,to borrow a phrase, The United States of Cancer

wren said...

Obama has been deep in Exelon's pocket since his state senate days. If it is serious, don't expect the truth about it.

wren said...

Hey! Limerick is built on a fault (or three), and they all know it.

Anonymous said...

You can use this interactive map from the Union of Concerned Scientists to track the relative safety record of your local NPP (if you live in the US). According to them Limerick #1 main safety issues are:

1) Elevated spent fuel pools

2) Ground water contamination

3) Earthquake Risk

they also have a few embarrassing stories

John said...

Yes, I will nitpick. Nuclear power is not carbon free. It takes a lot of carbon to mine, transport, and refine uranium, and to build the plants, and to deal with unusual events. If these are taken into consideration than there is a great deal of carbon needed to produce nuclear energy. I hope this BLOG will stop repeating the pro-nuclear propaganda or at least every time the pro-nuke side says its carbon free that we should say why it is not. We need to fight the propaganda. Not report the propaganda.

Anonymous said...


Anonymous said...

No danger to shareholders.

Anonymous said...

Unusual story: bestseller-list US author is willing, available immediately to teach in radiation-affected areas of Japan. Please forward this story and link as widely as possible. Thanks.

Anonymous said...


Limerick is not on/near an active fault line such as California or Japan. I would place my bets on the US collapsing before a major earthquake striking.

Anonymous said...

Same story, same fault at sizewell in UK !

Anonymous said...

@anon 7:50

"Limerick is not on/near an active fault line such as California or Japan. I would place my bets on the US collapsing before a major earthquake striking."

Neither was North Anna NPP before suddenly it was. How many buried pipes were ruptured under that plant that we don't know about?

The distant North Anna quake even shook Limerick to a halt.

A Nuclear Regulatory Commission study released less than a year ago ranked Exelon Nuclear's Limerick Generating Station as being the nation's nuclear plant with the third-highest risk of being damanged by an earthquake.

The study came about as a result of the U.S. Geologic Survey's 2008 updating of earthquake risks around the country using more sophisticated measurements and modeling than were used in the 1996 and 2002 versions.

As a result of the new data, the NRC has increased the risk of an earthquake damaging both reactors at Limerick by 141 percent, making it the third most at risk, after the Pilgrim Nuclear Plant in Plymouth, Mass., and the Indian Point Atomic Generating Station in Buchanan, N.Y.

Anonymous said...

VEPCO lied and withheld documents during their license applications for North Anna 1 and 2 in 1973. They were perfectly aware of the fault after a construction excavation wall for #1 collapsed in 1970.
They paid a $32,000 fine and...built the plants.

Anonymous said...

@ 7:03

I believe you it is just standard operating procedure for the industry (oops, we broke a rule? Sorry here’s some money, money fixes everything). Nuclear power was the first test of “Too Big To Fail” the plants are so incredibly expensive to build that the ratepayers are held hostage to their operation. Shoreham NPP in Long Island is a perfect example. LILCO knew from the beginning they couldn’t meet the NRC’s fairly lax evacuation requirement on a heavily populated island the size of Long Island. Instead of rethinking a NPP they went on with construction hoping the public would accept the plant in lieu of a threatened rate increase. In the end due to public opposition the NRC refused to grant Shoreham a full operating license. It was determined they couldn’t remotely meet the evacuation requirements. As punishment the local ratepayers were stuck with the 6 billion in wasted construction and decommissioning cost on a NPP that never generated a penny in profit. The Long Island Power Authority bought responsibility for the useless plant from LILCO for one dollar.

(Strangely enough LILCO paid Philadelphia Electric Company $50 million to take its fuel to the Limerick Nuclear Power Plant. ) I wonder if all the nuclear industry pays the nuclear industry to take unused fuel off their hands?

Actually I was trying to make the point that everything is "safe" until suddenly it isn't. Until TMI happened the US nuclear industry claimed it was impossible. Until Chernobyl happened the USSR claimed an accident of that magnitude was impossible. Until Fukushima happened the Japanese nuclear industry said it was impossible because their plants were designed to withstand anything nature could throw at them. After the fact suddenly the earthquake/tsunami was “outside of design parameters” which is just a fancy way of saying the experts are either incompetent or they lied. Never mind there was ample historic evidence of quakes and tsunami equaling the one generated in the great Tohoku quake. Notice no one has been called to task over the huge blunder of underestimating the possibility of damage in Fukushima. Was this the same genius that OK’ed other questionable NPP sites across Japan? In a sane world this person(s) would be up on criminal charges and thoroughly discredited. Instead this person(s) is probably leading a very comfortable life consulting for the industry and telling us everything is OK.

wren said...

Rahm Emanuel, David Axelrod and Obama all have extremely deep ties to Exelon.

They take hits on this from both the left and right, and yet the MSM never covers it.


Chicago mayor, former Congressman and Obama Chief of Staff Rahm Emanuel was a "key player" representing Unicom Corp., the parent of Commonwealth Edison, in forging its merger with Peco Energy Co. to create utility giant Exelon Corp. in 1999 when Goldman Sachs was also advising Unicom.[13][10] Additionally, "Obama's top political strategist, David Axelrod, was a consultant for Exelon."[10]

Exelon's Political Action Committee (PAC) is EXELONPAC.[14] The company is positioned to profit from "expensive carbon" and has been lobbying for cap and trade of carbon dioxide emissions.[15] "Exelon CEO John Rowe is a vociferous and longtime advocate of climate change legislation. In 2009, Forbes reported that if the Waxman-Markey climate legislation -- supported by Obama -- became law, 'the present value of Exelon's earnings stream would increase by $14 a share, or 28%.'"[10] Executives at the company have close ties to the Obama administration as advisors and fundraisers.[15] "Frank Clark, CEO of Exelon's Chicago-based subsidiary ComEd, was an Obama advisor and fundraiser, and Exelon director John Rogers has also raised funds for Obama."[10]

Anonymous said...

@Anonymous July 19, 2012 1:26 PM

I'm not worred about underground pipes being ruptured because above ground pipes can also rupture. I'm 41 and have lived in the area my whole life and I only experienced my first earthquake when we had the one last year that hit the east coast from the fracking operations down south. When the earthquake hit I thought a dump truck was driving by the building I work in until I did some googling and they reported a minor quake. Ask any old timer when is the last time they experienced an earthquake and you will get a perplexed reaction.

Anonymous said...


I don't think you're going to find ANY US president on either side of the fence that is actually against nuclear power or their money. Part of the vetting process is to make sure they are compliant to the whims of big business. A true anti-nuclear candidate would never make it on the ticket of either party. Democrats as a whole aren't really any more anti-nuclear than the Republicans. The Democrats didn't use their past majority in congress to change anything. The Democrat-led Senate Committee on Environment and Public Works did nothing to block NRC Chairman Gregory Jaczko’s resignation. Jaczko who was appointed by Obama was a thorn in the nuclear industry's side. He blocked Yucca mountain, called for a 50 mi exclusion zone in Japan (while the US still clings to a 10 mile circle). For these infractions against the industry Jaczko was railroaded for "abusing his staff" and lying to Congress about it. The nuclear industry has been caught in so many lies to Congress they had to open a huge library to store them all. The only punishment they get is huge subsidies, interest free loans and lax regulation. The Waxman-Markey climate legislation you mention includes subsidies for "clean" nuclear power. According to an EPA study passage of the legislation would result in twice as many NPP's being built than without passage.

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