Open House on Limerick Nuke Performance Set

Exelon Nuclear's Limerick Generating Station

If you have ever wondered how safe the Limerick Nuclear Generating Station is, Wednesday, April 18 is the time to find out.

That is the date that the U.S. Nuclear Regulatory Commission will conduct its annual "open house" to discuss the plant's performance over the prior year.

The meeting will take place at the Limerick Township Building, 646 West Ridge Pike, from 6 to 8 p.m. and is open to the public.

NRC staff members, including the on-site inspectors, will be on hand to discuss the plant's safety record over the year.

NRC oversight will be increased in 2012 as the result of a finding of "low to moderate safety significance," regarding the operation of Limerick's Unit 2 generator.

The finding was the result of "inadequate procedures" related to the operation of two main feedwater system valves, which would have been inoperable in the case of an accident  as a result of the problem.

As The Mercury reported in December, for a month last spring, two safety systems needed in case of a nuclear accident at Exelon Nuclear's Limerick Generating station were not working properly due to an error by plant personnel.

Exelon operates two boiling water reactors at the Limerick plant.

One, designed to get enough water to one of the nuclear reactors at the Limerick Generating Station during an accident; and another, designed to isolate radiation in the plant's containment building during an accident, would both have failed if called upon to perform during a nuclear accident, the NRC found.

An NRC team inspection is planned for the week of June 11 "to review the company's root cause and contributing cause evaluation for the problems; its assessment of potential similar issues; and its corrective actions to prevent a recurrence," according to an NRC release.

"Our expectation is that Exelon will thoroughly address the issues that contributed to the 'white' inspection finding finalized for Limerick late last year," NRC Region 1 Administrator Bill Dean said in the release.

"Ensuring that occurs will be a focus for the NRC in 2012," he said.

In 2011, "our inspectors spent time checking on whether there were any immediate safety concerns at U.S. nuclear power plants following the March events at the Fukushima Daiichi facility in Japan," Dean said. "Those reviews indicated the plants remained safe for continued operation."

Below is a timeline I put together that allows you to follow along with the developments after the earthquake and how they affected Limerick.

Earthquakes and Nuclear Plants on Dipity.

(If the timeline doesn't appear or work right, don't blame me. Every since I started paying for the Dipity service, it was gone straight down hill. If all else fails, in theory, you should be able to see the timeline by clicking on this link.)

The hydrogen explosion at Fukushima.

But one of the more significant outcomes of the NRC's review of the Fukushima disaster is an order for Limerick to install an upgraded venting system designed to correct the problem at the Japanese plant that allowed hydrogen to build up and cause an explosion that blew apart Japan’s Fukushima Dai-ichi nuclear reactor buildings last March, spreading radiation in a 40-mile radius and forcing the evacuation of 90,000 homes. .

As The Mercury reported here last month, Exelon Nuclear has until the end of 2016 to install a new ventilation system.

You can read the annual assessment for the Limerick plant for yourself on the NRC web site or by clicking here.