Dresden: More White Safety Relief Valve Problems?

This was a prolong event with uncontrollable quality in the safety relief valves (electromatic relief valve). I don't think the white finding is significant enough to create a organizational behavior change across Pilgrim, Dresden or Oyster Creek. 

September 16, 2015
EA-15-115

SUBJECT: FINAL SIGNIFICANCE DETERMINATION OF WHITE FINDING AND NOTICE OFVIOLATION; NRC INSPECTION REPORT NO. 05000237/2015010; DRESDEN NUCLEAR POWER STATION

This letter provides you the final significance determination of the preliminary White finding discussed in our previous communication dated July 1, 2015, which included U.S. Nuclear Regulatory Commission (NRC) Inspection Report No. 05000237/2015002; 05000249/2015002; 07200037/2015001. This report is available in the NRC’s Agencywide Documents Access and Management System (ADAMS) at Accession Number ML15219A500. The finding involved the failure of the Unit 2 “C” electromatic relief valve (ERV) to perform its intended safety function. 

Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion III, Design Control, requires, in part, that measures be established for the selection and review for suitability of application of materials, parts, equipment, and processes that are essential to the safety-related functions of the structures, systems, and components. Technical Specification 3.4.3, Safety and Relief Valves, Limiting Condition for Operation requires, in part, that in Modes 1, 2, and 3, the relief function of five relief valves shall be OPERABLE. Required Action A states that if one relief valve is inoperable, then restore the valve to operable status within 14 days. Required Action B states, in part, that if the Required Action and associated Completion Time are not met, then (1) be in Mode 3 within 12 hours and (2) be in Mode 4 within 36 hours.

Technical Specification 3.5.1, ECCS Operating, Limiting Condition for Operation requires, in part, that in Modes 1, 2, and 3, with pressure above 150 pounds per square inch gauge (psig), the Automatic Depressurization System (ADS) function of five relief valves shall be OPERABLE. Required Action H, states that, if one ADS valve is inoperable, then restore the valve to operable status within 14 days. Required Action I states, in part, that if the Required Action H and associated Completion Time are not met, then (1) be in Mode 3 within 12 hours, and (2) reduce reactor steam dome pressure to less than 150 psig within 36 hours.

Contrary to the above, from December 1, 2009, to February 7, 2015, the licensee failed to establish measures for the review of suitability of application for the ADS electromatic relief valve (ERV) actuators, which are essential to perform the safety-related reactor vessel depressurization and overpressure protection functions. This resulted in a failure of the 2C ERV, and an indeterminate period of inoperability and unavailability greater than allowed by Technical Specifications 3.4.3 and 3.5.1 during operating cycle D2C24. The 2C ERV inoperability during the operating cycle was identified after the failure of the valve during its first operational test in mid-cycle outage D2F56. Additionally, because the licensee was not aware of the valve’s inoperability between 2013 and 2015 during operating cycle D2C24, the required actions in Actions 3.4.3 A and B, and 3.5.1 H and were not followed.