NRC NEWS

U.S. NUCLEAR REGULATORY COMMISSION

OFFICE OF PUBLIC AFFAIRS, REGION I

475 Allendale Road

King of Prussia, PA 19406

No. I-00-79 November 20, 2000

CONTACT: Diane Screnci (610)337-5330/ e-mail: dps@nrc.gov

Neil A. Sheehan (610)337-5331/e-mail: nas@nrc.gov

NRC CITES CONSOLIDATED EDISON FOR VIOLATION AT INDIAN POINT 2

The Nuclear Regulatory Commission staff has cited Consolidated Edison Company of New

York for a violation of NRC requirements for steam generator tube inspections at its Indian Point 2

nuclear power plant in Buchanan, N.Y. The plant experienced a steam generator tube failure in

February 2000. While there were no public health and safety consequences from the February 2000

steam generator tube failure, which brought this violation to light, the NRC has determined that the

conditions associated with the violation were of high safety significance.

In its report issued in late August, an NRC inspection team preliminarily concluded that the

overall direction and execution of Consolidated Edison's 1997 steam generator inspections at Indian

Point 2 were deficient in several respects. Those deficiencies resulted in the company's failure to

adequately account for conditions which adversely affected the detectability of, and created increased

susceptibility to, steam generator tube flaws. The team concluded these failures resulted in tubes with

flaws being left in service following the 1997 inspection, until one of these tubes failed in February.

While the event did not adversely impact public health and safety, leaving the degraded tube in service

following the 1997 steam generator inspections resulted in a significant reduction in safety margin

during the plant’s operating cycle, based on the increased probability of a steam generator tube rupture.

The August NRC inspection report preliminarily characterized the findings as "red" and offered

the company an opportunity to attend a regulatory conference with the NRC staff. During a September

26 regulatory conference, Con Ed staff discussed an analysis of the probability of tube rupture, its

assessment of the significance of the issue and measures to prevent a recurrence. Based on the NRC’s

evaluation of this information, the NRC has lowered its calculation of the risk estimate in this case.

However, the NRC’s revised risk estimate remained above the threshold for classifying this finding as

“red,” an issue of high safety significance.

Under the NRC's revised reactor oversight process, the agency assesses inspection findings and

characterizes their risk significance by color, specifically green, white, yellow or red. A green finding

results in normal NRC oversight, while white, yellow or red assessments are considered progressively

more serious and receive commensurately greater oversight.
Although Con Ed’s risk analysis characterized this issue as a “yellow” finding, in a letter to

Con Ed, NRC Region I Administrator, Hubert J. Miller, said, “The NRC recognizes that there is a wide

band of uncertainty involved in such risk calculations and additional extensive review could possibly

remove some of those uncertainties. Our risk estimate, which classifies the finding as red, does

include a sensitivity analysis that for certain assumptions shows a range of results at the yellow/red

threshold.” As noted in an October 10th letter to the company, Indian Point 2 has been found to have

multiple degraded cornerstones. In response to the deficiencies at Indian Point 2, the staff is following

guidance in the NRC Action Matrix, which includes oversight of Con Ed’s performance improvement

plan and conduct of a significant team inspection.

Con Ed has 10 days to appeal the staff’s determination and must respond to the notice of

violation within 30 days.

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