New inspection report 2016004
This is a representative report indicating problems throughout the Industry with safety relief valves and PORV valves. Poor maintenance on the PORV valve gave us TMI. These problems go across the plant employees, manufacturers and vendors since 2006. The new valves were way less reliable than the old ones.
How we get to Pilgrim today is through the replacement of their two stage safety relieve valves. The reliability of the old valves were horrible. They put in refurbished three stage SRVs through the nuclear junks yards in 2011. The new SRVs began leaking emediately upon startup. They had horrendous leaking problems with the new valves effecting capacity factor. In 2013, I made a complaint to the NRC saying the valves have a common mode issues and they are extremely unreliable. The NRC blew me off. In the 2015 Blizzard hard plant trip and LOOP, two valves failed to operate when needed. We got here because I professionally so embarrassed the NRC.
1) The commonality between Millstone(PWR)and(Pilgrim) is upon startup with new valves, they emediately began leaking. It takes them many failures and many years to confront the defective new valves.
2) Generally the SRVs and PORVs are indicator components. It indicates the bureaucracies are dysfunctional.
3) With new valves and leaking, the NRC should have emediately ordered the plant to shutdown and fix them. On the second leak, we will shut you down for a year. That's being tough!!!
That is how you make everyone else behave in the industry.
· Annual Sample: Unit 2 ‘B’ Power Operated Relief Valve (PORV) Leakagea. Inspection ScopeThe inspectors performed an in-depth review of Dominion’s identification and correctionof conditions adverse to quality associated with repetitive leakage of Unit 2 PORVs sincemodification and installation in 2006 during 2R17.The inspectors assessed Dominion’s problem identification threshold, causal analyses,extent of condition reviews, compensatory actions, and the prioritization and timelinessof Dominion’s corrective actions to determine whether Dominion was appropriatelyidentifying, characterizing, and correcting problems associated with this issue andwhether the planned or completed corrective actions were appropriate. The inspectorscompared the actions taken to the requirements of Dominion’s CAP and 10 CFR 50,Appendix B and assessed the effectiveness of the implemented corrective actions.b. Findings and ObservationsNo findings were identified.In 2006, Dominion chose to upgrade the Unit 2 Pressurizer PORV and OperatorAssemblies to mitigate damage associated with repetitive installation and removal tosupport off-site surveillance testing of the original plant equipment. The new PORVswere designed to require less maintenance and to be tested in place. During each fuelcycle since installation, either one or both of the new PORVs have leaked by their closedvalve seats. This condition has resulted in Dominion isolating PORVs during each of thelast four fuel cycles. On November 17, 2016, Dominion isolated the ‘A’ PORV due toleakage as captured in CR1054065.The PORVs provide overpressure protection for the reactor coolant system (RCS) byrelieving pressure to the quench tank thereby protecting the RCS against brittle failure.Additionally, the PORVs are sized to ensure that departure from nucleate boilingspecified acceptable fuel design limits are not exceeded during analyzed events. Therated capacity per valve is one half the capacity that prevents lifting the RCS safetyvalves during normal plant operations and transients including a loss of load from fullpower. Furthermore, this capacity is sufficient to prevent lifting the safety valves in theevent of a continuous control rod withdrawal from low power, in conjunction with apressurizer pressure trip of the reactor. Blocking or isolating a PORV will prevent thevalve from automatically opening on demand.To correct PORV leakage Dominion has performed three recent ACEs with limitedsuccess. ACE 18846, from 2012, concluded that the incorrect subcomponents,mismatched valve seats and discs, were used when maintenance technicians swappedout a damaged seat during installation. Dominion also identified lost bench and post-maintenance testing opportunities in addition to training and procedural enhancements.In 2015, ACE 19950 found that Dominion failed to provide the vendor adequate testing28requirements in the purchase order for the PORVs. Dominion further identified that thewelded in configuration of the current PORV design does not allow for testing prior torestoring the system. ACE 1028983, in 2016, observed that Dominion failed to takeproper action upon identification of PORV leakage due to procedural weaknesses.The Dominion CAP procedure, PI-AA-200, provides instructions to station managementto ensure selection of the most appropriate causal analysis tools during CR screening.Consistent with previous screening, CR1054065 was screened as Significance Level 2,Potentially Significant Condition. These conditions are identified as precursors tosignificant events. PI-AA-200, Attachment 6, “CAQ Screening Matrix,” recommendsconsideration of a root cause evaluation (RCE) for potentially significant repetitiveconditions. The inspectors observed that Dominion initially elected to perform anotherACE for isolation of the ‘A’ PORV captured in CR1054065. However, consistent with ahealthy corrective action program, station staff assigned analysis of the issue identifiedthat the three recent ACEs had not successfully prevented PORV leakage andrequested elevation to a RCE to ensure the appropriate rigor. Dominion has scheduledcompletion of the associated RCE (CA3048134) for February 12, 2017.