A multi-disciplinary US Nuclear Regulatory Commission (NRC) team has begun a 'top-to-bottom' review at Entergy's Pilgrim nuclear power plant. The review will take a total of three weeks and is the third and largest NRC inspection conducted as part of the regulator's heightened scrutiny of the Massachusetts plant.
|Pilgrim (Image: Entergy)
The team of 20 inspectors will evaluate the state of equipment reliability, human performance, plant procedures and the steps taken by Entergy to address underlying issues that have affected the plant's safety performance. The team will also look at the plant's safety culture, which encompasses the freedom of employees to openly raise safety concerns.
The first part of the latest inspection began yesterday. Inspectors will remain on site for two weeks, returning in January for the final week. Team members will also be able to gather follow-up information whilst away from the plant. Their findings will be documented in a report to be released within 45 days after the inspection is finished. The NRC will also then issue a confirmatory action letter to Entergy, setting out the commitments and actions it must take in order to return to normal levels of oversight. This will only occur once the NRC is satisfied, through further inspections, that the requirements of the confirmatory action letter have been met.
Pilgrim, a single-unit 680 MWe boiling water reactor, entered service in 1972 and is currently licensed to operate until 2032. It has been receiving heightened regulatory oversight since September 2015, when the NRC changed its position on its Action Matrix, which uses inspection findings and performance indicators to guide the level of scrutiny at each plant.
The NRC assesses plant performance using colour-coded inspection findings and indicators ranging from green (very low safety or security significance) through white and yellow to red for issues of the highest significance. Pilgrim was moved to Column 4 on the matrix - under the category of "multiple/repetitive degraded" performance - after several findings of "white" performance indicators.
All but three of the USA's currently operating nuclear fleet of 100 units are currently in Column 1 and 2 of the matrix, with the majority fully meeting all safety and security performance objectives and requiring only baseline regulatory oversight. Ten units are in Column 2, with a small number of items of "low safety significance" to be resolved. Those plants receive extra regulatory inspections and follow-up of the corrective actions taken to address those issues.
No units currently appear in the NRC's third category of "degraded" performance, but three - Arkansas Nuclear One units 1 and 2 and Pilgrim plant - appear in Column 4, requiring increased regulatory oversight. No units currently appear in the in the NRC's fifth category of "unacceptable" performance.
Two NRC team inspections have already been completed at Pilgrim as part of the enhanced oversight program. The first, completed in January, examined aspects of the plant's corrective action, while the second, completed in April, focused on the effectiveness of that program. Both inspections identified one "green" (very low safety significance) finding each. Green inspection findings, the NRC says, indicate a deficiency in licensee performance that has very low risk significance and therefore has little or no impact on safety, meaning that the plant can continue to operate.
Entergy announced earlier this year that Pilgrim will be refuelled for the final time in 2017 and will cease operations on 31 May 2019.
Researched and written
by World Nuclear News