A single steam generator tube failure at Indian Point 2, which allowed reactor cooling water to escape and cause an alert at the plant, could have been prevented if owner Consolidated Edison had corrected “the deficiencies in its tube integrity programme” according to a Nuclear Regulatory Commission task group report. The task group was examining the shutdown of the plant in February 2000.
Using the Commission’s new colour-coded system of grading the safety significance of inspection findings, the NRC staff gave the event a “red” code finding, which means that the unit will receive the highest level of regulatory oversight. Con Ed had urged the NRC staff to issue no higher than a “yellow” finding.
(Under the NRC’s revised reactor oversight process, the agency assesses inspection findings and characterises their risk significance using a color code - 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.) The conclusion is contained in a 144-page “lessons learned” report on the event, issued 21 November, that the NRC staff said has broad implications for the US nuclear industry.
While the February 2000 alert resulted in no adverse impacts on public health and safety, the NRC staff said that by leaving the degraded tube in service following the 1997 steam generator inspections, Con Ed allowed the plant’s safety margin to degrade significantly during its operating cycle, increasing the probability of a steam generator tube rupture.
The NRC staff also cited ConEd for a violation of NRC requirements for steam generator tube inspections.
In November, Con Edison closed a deal with Entergy in which it sold the New Orleans-based company Indian Point 2, and the mothballed Indian Point 1, for $602 million.