05000247/FIN-2016002-01
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Finding | |
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| Title | CVCS Goal Monitoring Under the Maintenance Rule |
| Description | The maintenance rule requires that licensees shall monitor the performance or condition of structures, systems, or components, against licensee-established goals, in a manner sufficient to provide reasonable assurance that these structures, systems, and components are capable of fulfilling their intended functions. These goals shall be established commensurate with safety and, where practical, take into account industrywide operating experience. When the performance or condition of a structure, system, or component does not meet established goals, appropriate corrective action shall be taken. EN-DC-206, Maintenance Rule (a)(1) Process, provides the requirements and processes for managing SSCs for which (a)(2) monitoring has not demonstrated effective maintenance. EN-DC-206 specifies that (a)(1) action plans should not be closed until effectiveness of all corrective actions has been demonstrated by meeting performance goals through the monitoring period (or by other means specified in the action plan). Since 2013, there have been several repeat functional failures of equipment in the CVCS resulting in a failure to meet the performance criterion for reliability. These failures included: A failure of the 23 charging pump on August 6, 2013, after the internal oil pump discharge tubing broke causing the pump to trip on low oil pressure and a loss of charging. The 21 charging pump had tripped for the same reason in 2010. A failure of the 22 charging pump on January 14, 2014, due to cracked internal check valves caused by an inadequate fill-and-vent that left air in the pump following maintenance. The 21 charging pump had failed due to the same cause in 2013. A failure of the Unit 2 valve FCV-110A, boric acid flow control valve, to fully open on January 5, 2015. The valve had insufficient insulation; and as a result, boron crystalized above the valve plug and blocked its movement. The Unit 3 FCV-110A had failed in the same way in 2011, with earlier failures of other valves for the same cause going back to 1997. In each case, the CVCS for Unit 2 was already (a)(1), so Entergy either updated the existing (a)(1) action plan or created another one to operate in parallel with the existing one. Upon reviewing the associated (a)(1) action plans, the inspectors noted that in each example Entergys goals may not have been in accordance with EN-DC-206(a)(1) Process. It specifies that monitoring intervals should be at least six months for normally operating SSCs, at least three surveillances for SSCs monitored by surveillance and long enough to detect recurrence of the applicable failure mechanism. It also states that performance goals that provide reasonable assurance that the SSC is capable of performing its intended functions should be monitored throughout the time the SSC is classified (a)(1). EN-DC-206 defines an SSC as any discreet component grouping that has caused a monitoring failure, including any applicable extent of condition. In the examples provided, NRC inspectors challenged whether Entergy either chose a shorter monitoring interval or a goal that did not include the applicable extent of condition. Specifically: The (a)(1) action plan for the broken oil tubing had a goal of no noticeable decrease in 23 charging pumps running oil pressure for the next three quarterly surveillances. The chosen monitoring interval met the procedural expectation, but Entergy limited the monitoring to the 23 charging pump without written justification, when the 21 charging pump had failed previously for the same reason and the other pumps were susceptible to the same failure mechanism. During the monitoring interval, the 21 charging pump experienced low oil pressure. When Entergy performed repairs on the 21 charging pump for an unrelated issue, they discovered that the oil tubing had failed in the same way the 23 charging pump oil tubing had failed, although it had not yet caused a pump trip. The (a)(1) action plan for the cracked check valves had a goal of no check valve failure for six months for the next charging pump that underwent maintenance. This happened to be the 22 charging pump. Entergy chose a six-month monitoring interval, even though only one of the three charging pumps is in service at any given time, and the 22 charging pump only ran for four out of the six months it was monitored. Additionally, the action plan did not justify why a single successful filland-vent demonstrated adequate corrective actions. On November 19, 2014, during the six month monitoring interval, the 21 charging pump underwent maintenance requiring a fill-and-vent, and experienced check valve failure two weeks later on December 4. Entergy documented this as a maintenance rule functional failure, and discussed the possibility that it could be due to an inadequate fill-and-vent, but did not change the (a)(1) action plan. The (a)(1) action plan for FCV-110A specified a monitoring interval of six months to include the winter because the previous valve failures had all occurred during the winter months. However, the actual monitoring interval documented in the corrective action was from April to October 2015, and therefore did not cover the winter months as intended. In January 2016, Entergy performed maintenance on valve CH-297 on Unit 3, which is a heat-traced boric acid valve, and did not properly restore the insulation. The valve function was not impacted because it does not often contain high concentrations of boric acid. The (a)(1) action plans described above were all reviewed and approved by the maintenance rule expert panel. Further information regarding the performance of these SSCs is required to determine whether these issues of concern represent performance deficiencies and whether they are more than minor. (URI 05000247/2016002-01, CVCS Goal Monitoring Under the Maintenance Rule) |
| Site: | Indian Point  |
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| Report | IR 05000247/2016002 Section 1R12 |
| Date counted | Jun 30, 2016 (2016Q2) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.12 |
| Inspectors (proximate) | B Haagensen E Dipaolo F Arner G Newman J Amberosini J Furia S Elkhiamy S Richb Haagenseng Dentel G Newman J Furia J Poehler K Mangan N Floyd S Galbreath S Richb Haagenseng Dentel G Newman J Furia K Mangan N Floyd S Galbreath S Rich J Poehler |
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Finding - Indian Point - IR 05000247/2016002 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Indian Point) @ 2016Q2
Self-Identified List (Indian Point)
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