IR 05000289/1999007
| ML20212J010 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 09/27/1999 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20212J006 | List: |
| References | |
| 50-289-99-07, NUDOCS 9910040227 | |
| Download: ML20212J010 (14) | |
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U.S. NUCLEAR REGULATORY COMMISSION REGION 1
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Docket No.
50-289 License No.
DPR-50 Report No.
99-07 l
l Licensee:
GPU Nuclear,Inc. (GPUN)
Facility:
Three Mile Island Station, Unit i Location:
P. O. Box 480 Middletown, PA 17057 Dates:
July 18,1999 through August 28,1999 Inspectors:
Wayne L. Schmidt, Senior Resident inspector Oraig W. Smith, Resident inspector Lois M. James, Reactor Engineer, DRS
Approved by:
Peter W. Eselgroth, Chief Projects Branch No. 7 Division of Reactor Projects
1 9910040227 990927
PDR ADOCK 05000289 e
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EXECUTIVE SUMMARY Three Mile Island Nuclear Power Station Report No. 50-289/99-07 This integrated inspection included aspects of licensee operations, maintenance, engineering, and plant support. The report covers a six week period of resident inspection supplemented by a regional engineering programs inspection.
GPU Nuclear (GPUN) operated Three Mile Island Unit 1 (TMI) safely at 100 percent power throughout the inspection period.
Operations A control room operator appropriately responded to an indication of an overheated and smoking safety-related relay in the engineered safeguards actuation system (ESAS). The operability evaluation for the degraded relay was delayed because operators did not enter it into the corrective action program in a timely manner. Additionally, the operability evaluation was based solely on previous experience with less severe relay degradation and did not consider further l
testing as a means to verify operability of the degraded relay. GPUN subsequently replaced the l
relay and verified operability of the new relay through post-maintenance testing. (Section O2.1)
l Maintenance
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Surveillance testing of the A decay heat removal pump identified vibration levels in the American Society of Mechanical Engineers Code alert range during the last two surveillance runs l
conducted on July 1 and August 10. Prior to the August 10 surveillance, GPUN changed the
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surveillance procedure to a displacement based acceptance criteria for pump vibrations to more accurately reflect actual pump operating conditions. Initially, inservice Testing Engineering provided inadequate information to the Plant Review Group to support the proposed change to the surveillance procedure acceptance criteria. GPUN attributed the increased pump vibrations to flow induced virbrations and not to degraded pump performance. (Section M1.1)
GPUN continued to pursue a resolution of the ESAS relay failures. GPUN's root cause of the failures was thorough, and the assigned corrective actions were appropriate for resolving the apparent cause of the relay failures. (Section M2.1)
GPUN conducted the installation of temporary equipment in preparation for the refueling outage generally well. GPUN management took immediate corrective actions and emphasized to the work groups involved the importance of following the proceduralized scaffold erection and temporary electrical cable installation policies following identification of two minor isolated issues. (Section M8.1)
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Engineering
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System Engineering performed well in the analysis of decay heat removal pump vibration issues and in the testing and analysis of the control room emergency ventilation system. (Section E1)
The procedures supporting the 10 CFR 50.59 and Updated Final Safety Analysis Report updating processes were acceptable, providing comprehensive guidance and detailed responsibilities for implementing the requirements of 10 CFR 50.59 and 10 CFR 50.71(e).
(Section E3.1)
GPUN has implemented an acceptable 10 CFR 50.59 program that produced adequate applicability determinations and safety evaluations, met regulations and applicable plant procedures, and provided sufficient details and references to support the conclusions drawn.
(Section E3.2)
Plant Su' nort o
A fire door to the C make-up pump cubicle was found open and unattended. The C make-up pump was out of service at the time of the discovery. There was minimal threat from a fire that initiated either inside or outside the make-up pump cubicles r,3 reading to safety-related equipment.' (Section F8.1)
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TABLE OF CONTENTS
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. EXECUTIVE SUMMARY..................................................... ii TABLE OF CONTE NTS........................................................ iv 1. Operation s.............................................................. 1 01-Conduct of Operations........................................... 1 O2
' Operational Status of Facilities and Equipment....................... 1 O2.1 Degraded Engineered Safeguards Actuation System Relay......
I I. M a i ntenance.......................................................... 2 M1' - Conduct of Maintenance........................................ 2 M1.1 A Decay Heat Removal Pump Surveillance Testing.............. 2 M2 Maintenance and Material Condition of Facilities and Equipment..........
M2.1 (Update) Inspection Followup ltem 98-08-02 - Failure of ESAS Relays to Properly Reenergize...................................... 3 M8 Miscellaneous Maintenance issues.................................. 4 M8.1 Pre-outage Review of Staged Equipment....................... 4 Ill. Engineering........................................................... 5 E1 General Engineering........................................... 5
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E3 Engineering Procedures and Documentation......................... 6 E3.1 10 CFR 50.59 Safety Evaluation Program...................... 6
l E3.2 Implementation of 10 CFR 50.59 Program................... 6
i IV. Pla nt Su pport........................................................... 7 l
F8 Miscellaneous Fire Protection issues............................. 7 F8.1 Fire Door Found Open..................................... 7 V. - M anagement Meetings.....................................
.............. 8 X1 Exit Meeting Summary........................................... 8 INSPECTION PROCEDURES USED.......................................... 9 ITEMS OPENED, CLOSED AND DISCUSSED..................................... 9 i
LIST OF ACRONYMS USED.................................................. 10 iv i,
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Report Details
Summary of Plant Status GPU Nuclear Inc. (GPUN) operated Three Mile Island Unit 1 (TMI) at 100 percent power throughout the inspection period.
1. Operations
Conduct of Operations (71707)
The shift operating crews performed routine activities well and responded properly to annunciated alarms.
Operational Status of Facilities and Equipment (71707)
O2.1 Dearaded Enaineered Safeauards Actuation System Relav a.
Insoection Scope The inspector observed GPUN's response to a degraded Engineered Safeguards Actuation System (ESAS) relay coil. On July 23, following testing of the C channel of the reactor protection system (RPS), a control room operator (CRO) found an ESAS relay coil overheated and smoking. The ESAS uses this and similar relays to actuate safety-related components in response to indications of plant parameters reaching safety system actuation setpoints. Routine RPS and ESAS surveillance testing exercises these relays from the normally energized to the de-energized position to verify their safety-related function.' GPUN experienced oroblems over the past year during testing when the relays failed to retum to the fully energized position after being de-energized. In this condition, the relay coil draws an excessive electrical current and overheating can result.
- Other ESAS relay failures were discussed in two previous inspection reports (IR 50-289/98-08 and 99-03).
b.
Observations and Findinas The CRO took appropriate action to correct the overheated relay by pushing the relay into the fully energized position, correcting the overheated condition. The operability i
review for this degraded relay was delayed because the operating crew did not enter the condition intu lhe corrective action process (CAP) at the time of discovery. A CAP (T1999-0588) was generated the following morning by the system engineer when he was made aware of the relay failure. As a result, an operability evaluation was not conducted until approximately seven hours after the condition was first identified. GPUN determined that the relay remained operable without investigating for any possible relay damage as a result of the severe overheating and smoking. The operability evaluation relied on GPUN's past experience, with less severely degraded humming relays, that the relays had always been able to perform their design functions. No testing was conducted to verify the continued operability of the overheated and smoking relay.
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GPUN replaced the relay later that same day and verified the operability of the new relay through appropriate post-maintenance testing.
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Although the relay was ultimately replaced and tested, GPUN's initial response was not timely and did not thoroughly evaluate the degraded relay for continued operability. This example of a weakness in GPUN's implementation of its corrective action process was a minor issue not subject to the formal enforcement process.
c.
Conclusion A CRO appropriately responded to an indication of an overheated and smoking safety-related relay in the ESAS. The operability evaluation for this degraded relay was delayed because operators did not enter it into the CAP in a timely manner. Additionally, the operability evaluation was based solely on previous experience with less severe relay degradation and did not consider further testing as a means to verify operability of the degraded relay. GPUN subsequently replaced the relay and verified operability of the new relay through post-maintenance testing.
11. Maintenance M1 Conduct of Maintenance (61726)
M1.1 A Decav Heat Removal Pumo Surveillance Testina a.
Inspection Scooe The inspector reviewed GPUN's efforts to address high vibrations on the A decay heat removal pump (DH-P-1 A) and observed routine surveillance testing of DH-P-1 A on August 10. The testing was being performed at twice the normal frequency (i.e. every six weeks instead of every twelve weeks) because pump vibrations had increased to the American Society of Mechanical Engineers (ASME) Code alert range during the previous performance of the surveillance conducted on July 1.
b.
Observations and Findinas inservice Testing Engineering did not provide adequate, detailed information to support
the change in the DH-P-1 A surveillance acceptance criteria for vibrations during a Plant Review Group (PRG) meeting on August 6. The PRG requested that Engineering complete a more detailed evaluation and re-present it. On August 9, the PRG met again, and based on the revised engineering evaluation, approved the change in the surveillance acceptance criteria for vibrations from a velocity based criteria to a displacement based criteria. The inspectors found the approved procedure change, and the supporting engineering evaluation, acceptable. The change was made based on an engineering evaluation that the displacement based criteria was a more appropriate indicator of pump degradation for the frequency at which the increased vibrations were occurring. The ASME Code allowed use of either the velocity based or displacement acceptance criteria for evaluating vibration data for the decay heat removal pumps. The change to a displacement based acceptance criteria provided a greater margin to the ASME Code vibration required action range. The ASME Code requires that if the
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vibration levels exceeded the required action range, the pump is to be declared inoperable.
The inspector observed the surveillance testing of DH-P-1A conducted on August 10.
The vibration readings decreased from the previous test; however, the pump vibrations remained in the ASME Code alert range requiring an increased test frequency. The recorded vibrations did not exceed either the displacement or velocity based required action ranges.
Engineering evaluated the condition of DH-P-1 A and determined the increased vibrations were the result of flow induced vibrations and not of pump degradation. This determination was based in part on the analysis of the other parameters measured during the surveillance testing (i.e. differential pressure and flow rate) which showed no degradation in pump performance. The engineering evaluation of the pump vibrations and proposed system modifications are discussed in more detail in Section E1.
c.
Conclusions Surveillance testing of DH-P-1 A identified vibration levels in the ASME Code alert range l
during the last two surveillance runs conducted on July 1 and August 10. Prior to the August 10 surveillance, GPUN changed the surveillance procedure to a displacement based acceptance criteria for pump vibrations to more accurately reflect actual pump operating conditions. Initially, Inservice Testing Engineering provided inadequate
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information to the PRG to support the proposed change to the surveillance procedure
- acceptance criteria. GPUN attributed the increased pump vibrations to flow induced vibrations and not to degraded pump performance.
l M2 Maintenance and Material Condition of Facilities and Equipment (92902)
M2.1 (Uodate) Insoection Followuo item 98-08-02 - Failure of ESAS Relavs to Properly
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Reenergize a.
Insoection Scope The inspectors continued to follow GPUN's actions taken to address ESAS relay failures
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as documented in this inspection followup item (IFI). GPUN issued voluntary Licensee Event Report (LER)99-007 to document the relay failures and planned corrective actions. Revision 1 to this LER, issued on August 20, provided preliminary information regarding the root cause and long-term corrective actions, i
b.
Observations and Findinas GPUN determined that inadequate preventive maintenance was the cause of the relay failures. Specifically, over time gradual wear of moving parts and loosening of relay mounting screws went uncorrected and resulted in a frictional build-up. The condition allowed the moving components to occasionally bind while repositioning to the energized state after being de-energized. Additionally, GPUN identified thct the relays with the
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largest number of contacts had the highest failure rate due to the increased force needed to move the larger number of contacts.
GPUN estab!ished several long-term corrective actions to address this condition.
Approximately 64 relays will be replaced in the upcoming refueling outage, including all of the relays with the largest number of contacts. All of the relays will be inspected for loose mounting screws, and a preventive maintenance task will be established to periodically inspect the relays for loose components. The ESAS system will remain in the Maintenance Rule category (a)(1), requiring increased monitoring until the corrective actions have been shown to prevent recurrence of the relay failures.
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Conclusion GPUN continued to pursue a resolution of the ESAS relay failures. GPUN's root cause j
of the failures was thorough, and the assigned corrective actions were appropriate for
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resolving the identified cause of the relay failuros.
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M8 Miscellaneous Maintenance issues (62707)
M8.1 Pre-outaae Rcview of Staaed Eauipment a.
Inspection Scope The inspectors conducted normal plant tours as the refueling outage approached, looking for adequate installation of pre-staged equipment including scaffolding and temporary electrical power supplies, to ensure that the operability of equipment necessary to support continued plant operation was not effected.
b.
Observations and Findinas Generally, the inspectors found good installation of temporary equipment to support the i
upcoming outage. There was a significant amount of scaffolding erection in progress throughout the plant in preparation for the upcoming refueling outage. There were two weaknesses noted:
On August 20, the inspector identified a scaffold above the B motor driven
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emergency feed' water pump (EF-P-28) that was not seismically supported.
GPUN procedure 1440-Y-3, Scaffold Construction / Inspection and Use of Extension Ladders, required scaffolds that are located near safety systems to be seismically secured. The scaffold in question had been inspected and approved by the construction supervisor and operations prior to the inspector's discovery.
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GPUN immediately corrected the scaffold and entered the deficiency into the l
CAP (CAP T1999-0651). Other scaffolds were inspected and no other deficiencies were identified.
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On August 24, the inspector identified an energized temporary electrical power
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supply box with temporary electrical feed wires attached to a safety-related cable tray in the intermediate building. GPUN took appropriate actions, as documented
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in CAP T1999-0663, to remove the temporary cables and to brief the work crew to ensure that temporary electrical equipment is not supported by safety-related cable trays.
These two failures to follow the procedure for scaffolding installation were isolated instances and are considered minor issues, not subject to formal enforcement action.
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Concbsions GPUN conducted the installation of temporary equipment in preparation for the refueling outage generally well. GPUN management took immediate corrective actions and emphasized to the work groups involved the importance of following the proceduralized scaffold erection and temporary electrical cable installation policies following identification of two minor isolated issues.
Ill. Enaineerina E1 General Engineering (37551)
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Inspection Scope The inspectors reviewed several system engineering activities.
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Observations and Findinos System engineers performed well in support of plant operation.
System performance team review of the decay heat removal pumps provided
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good insight into possible enhancements to improve availability and operation.
Specifically detailed analysis of pump vibration data indicated the need to structurally stiffen the outboard pump bearing support structure. Based on the data and analysis GPUN determined to proceed with a modification on this
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bearing support to be installed during planned system outages over the next operating cycle, i
Testing on the control room emergency ventilation system demonstrated the I
ability of the system to meet its design basis of maintaining positive pressure in the control room with any single damper failure. This testing was a commitment
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from LER 99-03. GPUN also committed to update this LER to provide any additional corrective actions planned.
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Conclusions System Engineering performed well in the analysis of decay heat removal pump vibration issues and in the testing and analysis of the control room emergency ventilation system.
E3 Engineering Procedures and Documentation (37001)
E3.1 10 CFR 50.59 Safety Evaluation Proaram a.
Insoection Scope The inspectors reviewed selected procedures and interviewed licensee representatives to verify that: (1) procedural guidance had been established for implementing the requirements of 10 CFR 50.59 for proposed changes, tests, and experiments (CTEs),
including safety evaluations (SEs); and (2) procedural guidance had been established for updating the Updated Final Safety Analysis Report (UFSAR), as required by 10 CFR l
50.71(e).
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Observations and Findinas l
l The inspector reviewed administrative, modification, and licensing procedures that
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provided guidance and responsibilities related to 10 CFR 50.59 and 10 CFR 50.71(e)
requirements. The inspector determined that program procedure,1000-ADM-1291.01,
" Safety Review Process," was acceptable and current with regards to regulatory guidance. The procedure adequately delineated responsibilities for the various individuals who prepare, process and approve SEs. The inspector verified that the procedures for completing permanent modifications, temporary plant modifications, and procedures changes made reference to the 10 CFR 50.59 program. The inspectors
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further verified that procedure 1000-ADM-7320.01, UFSAR Document Change Control, I
provided adequate guidelines and references for updating the UFSAR.
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Conclusions The procedures supporting the 10 CFR 50.59 and UFSAR updating processes were acceptable, providing adequate guidance and detailed responsibilities for implementing the requirements of 10 CFR 50.59 and 10 CFR 50.71(e).
E3.2 Imolementation of 10 CFR 50.59 Procram a.
Insoection Scope
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l The inspector examined the quality of SEs for 10 CFR 50.59 changes to determine if SEs for permanent plant modifications, temporary plant alterations, and procedure changes addressed all safety issues pertinent to the associated CTEs.
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Obsentations and Findinas 50.59 Safety Evaluations - The inspector reviewed nine SEs and found the SEs to be in accordance with the requirements of 10 CFR 50.59 and applicable GPUN procedures and were performed by trained, qualified personnel. The SEs were found to be of sufficient detail and contain sufficient references to allow a knowledgeable person to reach similar conclusions. No undocumented, unreviewed safety question was identified.
50.59 Applicability Determinations - The inspector reviewed 12 CTEs for which 50.59 SEs were not performed and verified that the applicability determinations were made in accordance with the SE procedures and controls. The applicability determinations were of sufficient detail to support the no SE conclusion and the inspectors did not identify specific instances where SEs should have been completed.
UFSAR Updates and CTEs Report - The inspector reviewed the 1997 biennial report of changes made under 10 CFR 50.59 and selected UFSAR updates to verify that the changes and the associated 50.59 SEs were accurately described. The inspectors did not identify instances where a 10 CFR 50.59 SE was completed and not listed in the biennial report. The UFSAR had been appropriately updated pursuant to the requirements of 10 CFR 50.71(e).
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Conclusions The licensee implemented an acceptable 10 CFR 50.59 program that produced adequate applicability determinations and safety evaluations, met regulations and applicable plant procedures, and provided sufficient details and references to support the conclusions drawn.
IV. Plant SuDDort
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F8 Miscellaneous Fire Protection issues (71750)
F8.1 Fire Door Found Open During a routine plant tour on July 21, the inspector found the fire door to the C make-up pump (MU-P-1C) cubicle open and unattended. The door had been propped open to i
support decontamination efforts in the cubicle. Sometime during the decontamination efforts, a team of maintenance technicians entered the cubicle and the decontamination team left. The decontamination team did not close the door as they left, nor did they turn over to the maintenance technicians the fact that the door was required to be closed.
The maintenance technicians were the last work group to exit the cubicle and did not close the door upon exiting. This was similar to a condition on the A make-up pump
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l (MU-P-1 A) cubicle identified by the inspector in the previous inspection period. GPUN entered the issue into the CAP (CAP T1999-0586).
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The inspector found this to be a minor issue, and not subject to formal enforcement action. At the time the fire doors were found open, the make-up pumps were out of service for planned maintenance. There was no safety-related equipment located directly outside the make-up pump cubicles. Therefore, there was minimal threat from a fire that initiated either iriside or outside the make-up pump cubicles spreading to safety-
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related equipment.
V. Manaaement Meetinas X1 Exit Meeting Summary The inspector presented the engineering inspection results to members of GPUN management at an exit meeting on August 27. Following completion of the inspection period, the resident inspectors conducted an exit meeting with GPUN managers on September 8. GPUN staff comments conceming the issues in this report were documented in the applicable report sections. No proprietary information was included.
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9 INSPECTION PROCEDURES USED
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IP37001 10 CFR 50.59 Safety Evaluation Program i
IP37551 General Engineering l-IP61726 Surveillance Observation
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IP62707 Maintenance Observation IP71707 Plant Operations IP71750 Plant Support Activities-lP92902 Maintenance - Followup ITEMS OPENED, CLOSED AND DISCUSSED l
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Ooened:
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Closed:
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Discussed:
i 98-08-02 IFl Failure of Engineered Safety Actuation System Relays to Properly Reenergize (Section M2.1)
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LIST OF ACRONYMS USED ASME American Society of Mechanical Engineers CAP Corrective Action Process CFR Code of Federal Regulations CRO Control Room Operator
.CTEs Changes, Tests, and Experiments ESAS Engineered Safeguards Actuation System GPUN GPU Nuclear, Inc.
IFl Inspection Followup Item IR inspection Report LER Licensee Event Report
- NRC Nuclear Regulatory Commission PDR Public Document Room PRG Plant Review Group RPS Reactor Protection System SEs Safety Evaluations TMI Three Mile Island-Unit 1 UFSAR Updated Final Safety Analysis Report i
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