US nuclear power generators fail during tests

In a failure that paralleled those at Fukushima in Japan, generators in US nuclear power stations failed during tests at the Seabrook Station in New Hampshire and 32 other US plants in the past eight years, according to a report by US Representative Edward J Markey's office.

Markey's report related to backup generators that failed, making them inoperable for at least a day, and noted that  there had been at least 69 reports of problems with emergency diesel generators during tests conducted at 33 nuclear plants.

It was found that a total of 48 reactors had been affected, with failures at 19 that lasted over two weeks and six that lasted longer than a month, according to the report.

According to Neil Sheehan, a spokesman for the Nuclear Regulatory Commission (NRC), the agency took the maintenance and testing of emergency diesel generators very seriously, as their lack of availability raised plant safety risk.

He added that the NRC had taken enforcement action against many plants for problems involving the generators. He said the agency also tracked issues associated with them through its Performance Indicators and inspections.

At Seabrook, Griffith stressed that there were three separate power lines that supply the plant and multiple levels of redundancy in case of power loss.