Plymouth's Pilgrim nuclear plant prepares to restart after leak

www.patriotledger.com
23 February 2011

The Pilgrim nuclear power plant in Plymouth was expected to be back in business Wednesday afternoon following a three day shutdown to repair a leak in a cooling system. Operators started a controlled shutdown of the 685 MW plant early Sunday and notified the Nuclear Regulatory Commission.

Plant spokesman David Tarantino said this morning that workers were putting the plant back on line. The plant was shut down after monitors detected a leak in a tube that carries salt water and is used in a cooling system. The plant is next to the ocean and uses sea water to cool the steaming hot fresh water that turns the plant's electricity generating turbines.

Duxbury anti nuclear activist Mary Lampert wasn't worried about the repair. Lampert said David Lochbaum, a nuclear engineer and Union of Concerned Scientists specialist, said the leak was "no big deal". The state's only nuclear plant was operating at 100% capacity when the shutdown occurred. It had been on line for 634 consecutive days "a record for us", Tarantino said when the shutdown was ordered Sunday.

Entergy Corp., which operates the facility, said in a report that "this event had no impact on the health and/or safety of the public". The report said that a section of a reactor building was "declared inoperable" Feb. 18 and could not be repaired within 72 hours, prompting the shutdown at 12:01 a.m. Sunday.

Last week, The Patriot Ledger reported that the level of groundwater contamination from a radioactive isotope in a well at the plant had plunged in recent weeks, but the plant's operators didn't seem to be much closer to determining the source of the problem. Despite the sharp decline, representatives for the Plymouth plant and the Nuclear Regulatory Commission said it's far too early to know if the groundwater concern has gone away.

Last summer, tritium levels in a monitoring well at the Plymouth plant exceeded 25,000 picocuries per liter, adding to concerns about a potential leak at the plant.

The tritium levels in the monitoring well exceeded the federal maximum for drinking water of 20,000 picocuries per liter only on one other occasion, in September. The tritium levels in that well have fluctuated wildly, however, since that time and have generally been significantly above levels that could be caused by typical atmospheric conditions.

In recent weeks, the levels have fallen, according to the Nuclear Regulatory Commission. The tritium levels in the well fell from 7,000 picocuries per liter in mid January to roughly 1,000 picocuries per liter by the end of the month. The levels in the second half of January were the lowest recorded since the well was first used last spring. Also last week, a major manufacturer in the nuclear industry reported a potential "substantial safety hazard" with control rods at the Pilgrim nuclear power plant and more than two dozen other reactors around the country.

The NRC reported at that time that GE Hitachi Nuclear Energy had discovered extensive cracking and "material distortion", and likely would recommend that the boiling water reactors using its Marathon control rod blades replace them more frequently than they had been told to previously.