NRC looks for trends at Vermont Yankee following latest problem with cooling tower

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(Host) The Nuclear Regulatory Commission wants to know if repairs made last year contributed to the latest problem with Vermont Yankee’s cooling towers.

The NRC sent a team of inspectors to investigate a cooling water leak that’s caused the plant to cut power by 75% at a time of high demand.

VPR’s John Dillon has more.

(Dillon) The towers are used to cool the plant’s water before it’s returned to the Connecticut River.

Last summer, one of the tower’s collapsed, sending water cascading out of the three-story structure.

Now the NRC wants to know why the cooling system again sprang a leak after extensive repairs were made. Neil Sheehan is a commission spokesman

(Sheehan) We are always looking for trends. And certainly they had the partial collapse in August 2007. Now they’ve had the leakage occur even though there was a considerable amount of time and work invested in trying to address the problem last year.

(Dillon) Last year’s tower collapse was caused by rotting wooden beams. Sheehan’s said this year’s cause seems to be different.

(Sheehan) Entergy is telling us it’s a different degradation mechanism this time around. They had a wood rot situation that occurred last year that impacted that one cooling tower cell. This time around it may have been related to changes they made in the wake of that problem.

(Dillon) Yankee spokesman Rob Williams said replacement parts that connect vertical and horizontal beams failed in both cooling towers.

The failure caused a water pipe to leak at a slip joint, spilling about 60 gallons a minute. Williams said the company last year apparently installed parts that were too weak to bear the load.

(Williams) Well, they clearly were not strong enough. This connection was between the recently replaced columns and the supports that actually hold the pipe… Those connections should have been stronger, and so that’s the design change we put into place.

(Dillon) The NRC has also sent its director of operations to Vermont Yankee to consult with inspectors and report back to the commission. Sheehan said the decision to dispatch the top officials is a sign of how seriously the commission views the situation.

Yankee spokesman Williams said the company realizes it has damaged its reputation.

(Williams) Certainly, it doesn’t reflect well. But we are doing the conservative thing. We have reduced plant power, taken both towers out of services, and doing a careful, methodical approach to making these corrections.

(Dillon) Last year, the NRC criticized Yankee for failing to conduct a hands-on inspection of the cooling tower components.

For VPR News, I’m John Dillon in Montpelier.



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