Palo Verde-3 still in Column 4, but other units show improvement

Palo Verde-3 remained the only reactor in Column 4 of NRC's action matrix, requiring the highest level of agency oversight short of a plant shutdown, in fourth-quarter 2007.

However, the number of units in Columns 2 and 3 -- which require increasing levels of NRC inspection activity -- decreased from the prior quarter. The number of units in Column 2 -- the regulatory response column -- dropped to eight in the fourth quarter, from 14 in third-quarter 2007. The number of reactors in Column 3 -- the degraded cornerstone column -- dropped to eight, from nine the previous quarter.

Column 4 -- the multiple/repetitive degraded cornerstone column -- indicates degraded performance in one of seven safety cornerstones and is only one step above Column 5, which finds plant performance unacceptable and would require shutdown.

Also, the number of units with identified cross-cutting issues increased, from 18 at mid-2007 to 28 by year-end. NRC evaluates whether a substantive cross-cutting issue exists at each operating reactor twice a year -- at mid-cycle and year-end.

While Palo Verde-1 and -2 stayed in Column 3, NRC said in an annual assessment letter sent earlier this month to Arizona Public Service Co. that there would continue to be increased inspections and attention to the actions plans at all three units because the root causes of the problems were site-wide.

There were six other units in Column 3: Farley-1 and -2 and Kewaunee, all of which had been in that category in third-quarter 2007, were joined by Browns Ferry-1 (which restarted last May after a 22-year shutdown) and had previously been in Column 1; Fort Calhoun, which had been in Column 2; and Salem-1, which had been in Column 1.

Both Brunswick units showed improved performance in the fourth quarter; unit 1 moved to Column 2 from Column 3 in the prior quarter, and unit 2 moved to Column 1 from Column 2 in the third quarter.

Byron-2, Cooper, Hatch-2, Nine Mile Point-1, Perry, and Vogtle-1 and -2 remained in Column 2.

However, Clinton, Duane Arnold, Oconee-1 and -2, and Vermont Yankee improved, moving from Column 2 in the third quarter to Column 1 at the end of 2007.

Cook-1 and -2, which had been in Column 3 in the third quarter, moved to Column 1 in the fourth quarter.

Oconee-3 improved performance and moved from Column 3 to Column 1.

NRC's reactor oversight process collects information from inspections and performance indicators and uses that information to determine the agency's inspection effort at nuclear plants. Under the agency's action matrix, NRC provides a baseline level of inspection effort for plants listed in Column 1. NRC increases the level of oversight as plants move from Column 2 to Column 4.

Under NRC's system of color-coding inspection findings and performance indicators, green indicates very low risk significance. White, yellow, or red inspection findings or performance indicators signify increasing degrees of safety significance.

Created: March 24, 2008

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