May 2014: Finding a chunk of PCP impeller lodged in the core barrel inspection report.
Issues of concern:
1) You see with the PCP seal and the CCW seal the pattern of not following procedures and bum procedures.This place and the NRC reeks with the smell of procedure problems.
2)
With the safety injection tank, this is on the NRC with letting them get away with leaks from 2010. Hasn't anyone learned the lessen with the safety injection/refueling water tank. Basically making assumption on incomplete information...this is a pattern with thee guys.
3) I have issues the of the timelessness of the of the PCP seal failure.
***Green. A finding of very low safety significance and an associated NCV of Technical Specification (TS) 5.4.1(a) was self-revealed when the ‘C’ primary coolant pump (PCP) seal degraded as a result of an inadequate maintenance procedure. Specifically, maintenance procedure PCS–M–54, “N–9000 Primary Coolant Pump Shaft Seal Assembly,” did not identify critical steps in the assembly of the PCP seal and, as a result, the work activity was not adequately controlled. This issue was entered into the licensee’s Corrective Action Program (CAP) as CR–PLP–2014–03495, Planned Outage Required Due to Two Stages of the Primary Coolant Pump P-50C Seal Not Performing as Expected, dated June 21, 2014.
***Green. A finding of very low safety significance and an associated NCV of TS 5.4.1(a) was self-revealed on January 6, 2015, after the licensee identified smoke coming from the ‘C’ component cooling water (CCW) pump (P–52C) as a result of incorrect assembly of the inboard pump bearing in December 2014, due to an inadequate maintenance procedure. This issue was entered into the licensee’s CAP as CR–PLP–2015–00063, Workers Reported Smoke Coming from Shaft of P–52C, dated January 6, 2015. Inoperability of Safety Injection Tank Due to Long-Term Leakage
Introduction: A finding of very low safety significance (Green) and an associated NCV of 10 CFR Part 50, Appendix B, Criterion XVI, “Corrective Action,” was identified by the inspectors when licensee personnel failed to ensure that leakage out of the ‘B’ SIT, a condition adverse to quality, was corrected in a timely manner. Specifically, although minor water leakage out of the ‘B’ SIT had been occurring since at least 2010, the licensee failed to adequately address the leakage despite several plant outages that provided an opportunity to perform maintenance.
***Green. A finding of very low safety significance and an associated NCV of 10 CFR 50, Appendix B, Criterion XVI, “Corrective Action,” was identified by the inspectors when licensee personnel failed to assure that leakage out of the ‘B’ safety injection tank (SIT), a condition adverse to quality, was corrected in a timely manner. Specifically, although minor water leakage out of the ‘B’ SIT had been occurring since at least 2010, the licensee had not corrected the leakage despite several plant outages that provided an opportunity to address the issue. This issue was entered into the licensee’s CAP as CR–PLP–2014–04861, B SIT Declared Inoperable Due to Reaching Technical Specification Low Level Setpoint, dated October 7, 2014
***Green. A finding of very low safety significance and an associated NCV of 10 CFR 50, Appendix B, Criterion III, “Design Control,” was identified by the inspectors when the licensee credited fire doors for High Energy Line Break (HELB) protection without a supporting test or evaluation. Specifically, Procedure 4.02 credited fire doors with protection of safety-related equipment against a HELB when the primary HELB barrier was disabled without a test or evaluation to demonstrate the doors could withstand the HELB environment. This issue was entered into the licensee’s CAP as CR–PLP–2015–00371, NRC Concerns with Calculation EA–PSA–CCW–HELB–02–17, dated January 22, 2015.
Severity Level IV. A Severity Level IV NCV of 10 CFR 50.59(d)(1), “Changes, Tests, and Experiments,” and an associated finding of very low safety significance was identified by the inspectors when licensee personnel failed to maintain a written safety evaluation that provided a basis that the use of temporary alligator clip jumpers to maintain emergency diesel generator (EDG) operability during certain maintenance activities did not require a license amendment. Specifically, the licensee did not address the adverse effects of the use of alligator jumpers on the design and qualification of the diesel generator (DG) circuit breaker used per Engineering Change 50310 and changes to procedure SPS–E–1, “2400 Volt and 4160 Volt Allis Chalmers and Siemens Vacuum Circuit Breaker Auxiliary Switch Adjustments,” Revision 34. This issue was entered into the licensee’s CAP as CR–PLP–2014–04859, NRC Identified 50.59 Issue, dated October 7, 2014.
***Severity Level IV. A Severity Level IV NCV of 10 CFR 50.59(d)(1), “Changes, Tests,
and Experiments,” and an associated finding of very low safety significance was
identified by the inspectors when licensee personnel failed to maintain a written safety
evaluation that provided a basis that the use of temporary alligator clip jumpers to
maintain emergency diesel generator (EDG) operability during certain maintenance
activities did not require a license amendment. Specifically, the licensee did not address
the adverse effects of the use of alligator jumpers on the design and qualification of the
diesel generator (DG) circuit breaker used per Engineering Change 50310 and changes
to procedure SPS–E–1, “2400 Volt and 4160 Volt Allis Chalmers and Siemens Vacuum
Circuit Breaker Auxiliary Switch Adjustments,”
This should have been 50.59 and indicates 50.59 violations are more widespread than known. It is a failure of the NRC enforce regulations (50.59s).
Revision 34. This issue was entered into
the licensee’s CAP as CR–PLP–2014–04859, NRC Identified 50.59 Issue, dated
October 7, 2014.
More primary coolant problems...so now for the first time the NRC admits there is a pattern with numerous PCP issues?
Selected Issue Follow-up Inspection: Primary Coolant Pumps
a. Inspection Scope
The inspectors have documented several issues related to PCPs at Palisades over the past several years. The inspectors documented completion of an Operability Determination inspection sample that reviewed increased vibrations on the ‘C’ PCP in IR 05000255/2011005. A Green finding and associated NCV was documented in Section 1R15.b of IR 05000255/2012003 for the operation of PCPs outside their design operating criteria. Another Operability Determination inspection sample was documented in IR 05000255/2013002, which reviewed an oversized PCP impeller. The inspectors documented completion of a post-maintenance testing inspection sample following replacement of the ‘C’ PCP impeller in Section 1R19 of IR 05000255/2014002. Section 1R20 of that same IR documented a comprehensive review of the history of PCP issues at Palisades and the review of a piece of PCP impeller that was unable to be removed from the reactor vessel. The inspectors documented completion of another Operability Determination inspection sample that reviewed degradation of the ‘C’ PCP seal in IR 05000255/2014003. Section 1R20 of that same IR documented that the licensee performed a maintenance outage to replace the degraded ‘C’ PCP seal and Section 4OA2.4 documented a review of the licensee’s planned actions to address the NCV documented in 2012.
During this inspection period, the inspectors continued their collective and ongoing review of the numerous PCP issues at Palisades. Of particular focus was a review of the licensee’s root cause evaluation for degradation of the ‘C’ PCP seal that was initially installed during refueling outage 1R23 in spring 2014 and replaced during a summer 2014 maintenance outage. The inspectors also remained aware of the licensee’s plans and progress in resolving the NCV issued in 2012, and planned to continue to assess the timeliness of corrective action implementation.
This review constituted one in-depth problem identification and resolution sample as defined in IP 71152–05.
b. Findings
Inadequate Procedure Leads to Primary Coolant Pump Seal Degradation
Introduction: A finding of very low safety significance (Green) and an associated NCV of TS 5.4.1(a) was self-revealed when the ‘C’ PCP seal degraded as a result of an inadequate maintenance procedure. Specifically, maintenance procedure PCS–M–54, “N–9000 Primary Coolant Pump Shaft Seal Assembly,” did not identify critical steps in the assembly of the PCP seal and, as a result, the work activity was not adequately controlled.
Description: During RFO 1R23, from January through March 2014, the ‘C’ PCP seal was replaced as a planned maintenance activity. Prior to the RFO, the vendor provided training to plant maintenance personnel on seal disassembly, assembly, and installation. The seal package was assembled by site personnel using procedure PCS-M-54, “N–9000 Primary Coolant Pump Shaft Seal Assembly,” Revision 6, on the spent fuel pool floor with oversight from the vendor. This activity also included pre-installation testing and cleaning. The seal was then lifted into containment and installed in the pump.
On March 16, 2014, a few days after plant startup from RFO 1R23, the licensee identified that the ‘C’ PCP seal package breakdown pressures for the middle and lower stages were not trending as expected. An operational decision-making instruction (ODMI) was written to provide guidance to the operators on steps to take if the pressures increased, the pressure breakdowns between the seals decreased, or the controlled bleed-off flow increased. On May 13, 2014, following safety injection system surveillance testing, the control room received an alarm for ‘C’ PCP seal abnormal pressure and entered the abnormal operating procedure (AOP). This also exceeded trigger points in the ODMI. The middle seal stage was declared failed and an engineering evaluation was performed to determine the condition of the remaining seals and if the pump could continue to operate safely. The pump was deemed safe for continued operation and the ODMI trigger point criteria were revised based on the most recent data.
Based on continued slow but steady seal degradation, the
The transient of shutdowns cause damage to safety equipment.
licensee decided to shut down the plant on June 21, 2014, to replace the seal. The transient of shutting down the unit caused the lower stage of the seal to fail, as well as the previously declared failed middle stage. The upper and vapor stages of the seal remained fully functional. After the seal package was replaced, the unit was re-started from the maintenance outage on June 26, 2014. The licensee entered this issue into the CAP as CR–PLP–2014–03495, PCP P–50C Seal Cartridge Exceeded ODMI Minimum Pressure Drop for Two Stages,
on June 24, 2014.
A root cause evaluation was conducted to determine the cause of the seal stage failures. The removed seal was sent to the vendor for analysis after it was removed. The vendor was able to rule out many potential causes including the seal being dropped, inappropriately pressurizing the seal, increased or abnormal pump
My theory was the big impeller blade missing could damage pump bearings the bearing due to excess vibration. The C pump is the same pump with impeller missing and the seal damaged.
vibrations, and foreign material intrusion. Interviews with maintenance personnel were also conducted. The direct cause was determined to be the stationary faces for the middle and lower stages of the seal not being sufficiently seated to allow the o-ring to seal and thus allowing leakage through the stages past the o-rings. No definitive root cause was determined. However, a probable root cause of not classifying the seal assembly as a critical maintenance activity, which would have provided additional training, oversight, and critical step identification, was identified. There was also a misunderstanding of the pre-installation testing; the licensee believed this testing would identify any assembly issues, when in fact it would only detect gross leakage or major assembly errors.
Analysis: The inspectors determined that not maintaining an adequate procedure to assemble and install the ‘C’ PCP seal was an issue of concern and evaluated the issue in accordance with IMC 0612, Appendix B. The issue of concern was not associated with any willful or traditional enforcement aspects. The inspectors determined that the issue of concern was within the licensee’s ability to foresee and correct and represented the failure to meet a standard in that the licensee did not maintain appropriate maintenance procedures as recommended in Regulatory Guide 1.33, Revision 2, Section 9.a, which the licensee was committed to in TS 5.4.1(a). Therefore the issue of concern represented a performance deficiency.
The inspectors determined that the performance deficiency was more than minor because it was associated with the Equipment Performance attribute of the Initiating Events cornerstone and adversely affected the cornerstone objective of limiting the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations.
The inspectors evaluated the issue in accordance with IMC 0609, Attachment 4. The questions in Table 3 were answered "No" and the inspectors continued the significance evaluation in accordance with IMC 0609, Appendix A. The inspectors reviewed the Initiating Events questions in Exhibit 1 and answered "Yes" to the Loss of Cooling Accident (LOCA) Initiators screening question, “After a reasonable assessment of degradation, could the finding result in exceeding the reactor coolant system leak rate for a small LOCA,” because the first two seal stages ultimately failed and if the 3rd stage had failed, a PCP seal LOCA may have occurred resulting in a small break LOCA. Therefore, a detailed risk evaluation was performed by a Region III SRA.
The change in risk for this performance deficiency was best characterized by the risk associated with the manual reactor shutdown that occurred. The SRAs performed the analysis using the Palisades SPAR Model Version 8.20, SAPHIRE Version 8.1.2.0. A “Transient” initiating event analysis was run using the SPAR model. The result was an estimated conditional core damage probability (CCDP) of 4.17E–07. The CCDP result included risk due to Anticipated Transient Without Scram (ATWS) scenarios. The SRAs reviewed the results that did not contain reactor protection system failures, and obtained a revised CCDP for non-ATWS transients of 1.81E–08. Given this result, the SRAs concluded that the change in risk for the performance deficiency was less than 1E–07/year (i.e., ΔCDF < 1E–07/year). The dominant sequence involved a transient with failure of safety valves to reclose after opening, failure of shutdown cooling, and
failure of high pressure recirculation.
Based on the detailed risk evaluation, the inspectors determined that the finding was of
very low safety significance (Green).
This finding had a cross-cutting aspect in the Work Management component of the Human Performance cross-cutting area. Specifically, the licensee did not effectively screen the PCP seal assembly through the work management process to identify that it should have been classified as a critical maintenance activity. In addition, insufficient emphasis was placed on in-field vendor oversight during work execution. (H.5) Enforcement: Technical Specification 5.4.1(a), states, in part, that written procedures shall be established, implemented, and maintained as recommended in Regulatory Guide 1.33, Revision 2, dated February 1978. Section 9.a, “Procedures for Performing Maintenance,” states in part, “Maintenance that can affect the performance of safety related equipment should be properly preplanned and performed in accordance with written procedures, documented instructions, or drawings appropriate to the circumstances.” Procedure PCS–M–54, “N 9000 Primary Coolant Pump Shaft Seal Assembly,” Revision 6, contained instructions for assembly of safety-related PCP seals.
Contrary to the above, during RFO 1R23, maintenance personnel completed assembly of the ‘C’ PCP seal using procedure PCS–M–54, which did not include critical steps to validate that the seal was assembled correctly prior to operation. As a result, the ‘C’ PCP seal stages degraded during plant operation such that a subsequent plant outage was necessary to replace the seal. Because this issue was of very low safety significance and because it was entered into the CAP as CR–PLP–2014–03495, this violation is being treated as an NCV consistent with Section 2.3.2 of the NRC Enforcement Policy. (NCV 05000255/2015001–07, Inadequate Procedure Leads to Primary Coolant Pump Seal Degradation)
