Xcel Energy found in 1996 that a battery charger at the Prairie Island nuclear plant in Red Wing was faulty but didn’t replace it until this year.
Glen Stubbe, Star Tribune
Xcel slapped over faulty equipment at Prairie Island
- Article by: DAVID SHAFFER
- Star Tribune
- August 17, 2011 - 9:06 PM
Federal regulators said Wednesday that Xcel Energy Inc. violated safety regulations for years by keeping a faulty charger for backup batteries at the Prairie Island nuclear power plant.
The Nuclear Regulatory Commission confirmed its June preliminary finding that the issue had "low to moderate safety significance," which triggers enhanced inspections at the plant. Xcel had argued the so-called "white" finding was excessive.
The NRC rates safety issues with a color-coded system that classifies findings as green, white, yellow or red, in increasing order of significance. Green is "very low" safety significance; yellow is substantial.
It is the fifth time the plant in Red Wing, Minn., has been issued such a "white" finding. It has not had more severe violations.
Xcel conceded that the problem, first identified in 1996 during a simulation test, was not dealt with properly. The faulty charger on Unit 1 was replaced in May, after Xcel self-reported the issue and NRC inspectors took a closer look. Another charger on Unit 2 will be replaced at the next refueling, Xcel said.
"We are committed to operating our nuclear plants safely, and we take this matter very seriously," Mark Schimmel, Prairie Island site vice president, said in a statement. "These findings and the process that led to them highlight the stringent regulatory oversight of the nuclear industry in the United States."
The charger would lock up and stop recharging one of four battery packs when the plant's outside power source was cut off and the plant switched to diesel generators. Instead of fixing or replacing the charger, the utility for years turned off the charger during simulation tests. If the charger tripped off when needed, Xcel workers were to manually reset it.
"Even though this issue did not have an impact on routine plant operation or members of the public, the NRC requires safety-related equipment to be operable in accordance with the conditions of the plant's operating license," NRC regional administrator Mark Satorius said in a statement. "Contrary to these requirements, battery chargers at Prairie Island Unit 1 were susceptible to failure under certain conditions."
Xcel said it is reviewing the NRC's action and has until Sept. 16 to decide whether to contest the white finding.
David Shaffer • 612-673-7090
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