IR 05000219/1986035
| ML20215C267 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 11/24/1986 |
| From: | Anderson C, Chung J, Joe Golla NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20215C254 | List: |
| References | |
| 50-219-86-35, NUDOCS 8612150083 | |
| Download: ML20215C267 (12) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION I
Report No. 86-35 Docket No.
50-219 License No. OPR-16 Priority Category C
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Licensee: General Public Utilities Nuclear Corporation Post Office Box 338 Forked River, New Jersey 08731 Facility Name: Oyster Creek Nuclear Generating Station Inspection At:
Forked River, New Jersey Inspection Conducted: October 26-29, 1986 Inspectors:
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/ /- /9 - 84, ph A/ Golla, eact'dr Engineer date
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W. C un, 1d eactor Engineer date Approved by:
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// 2 f G Clifffd J. Anderson, Chief date Plant Systems Section, EB Inspection Summary:
Inspection conducted October 26-29, 1986 (Inspection Report No. 50-219/86-35)
Areas Inspected: Routine unannounced inspection of test witnessing and preliminary results evaluation of containment integrated leak rate test (CILRT) and final results evaluation of local leak rate test (LLRT).
Results: No violations or deviations were identified.
8612150083 861205 PDR ADOCK 0500
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DETAILS 1.
Persons Contacted Licensee G. Busch, Licensing Engineer M. Dunsmuir, QA Monitor W. Emrich, Senior Engineer
- P. Fiedler, Vice President & Director, Oyster Creek
- V. Foglia, P.M. Manager
- J. Maloney, Manager Plant Material
- J. Molnar, Core Engineering Manager D. Notigan, Core Engineer
- E. Scheyder, MCF United States Nuclear Regulatory Commission
- W. Bateman, Senior Resident Inspector
- J. Wechselberger, Resident Inspector
- Denotes those present at exit meeting, held on October 29, 1986.
2.
Licensee Actions on Previous Inspection Findings (Closed) Unresolved Item (50-219/84-26-01):
CIRLT computer program inappro-priately assigns volume fractions after RTDs are taken out of service. The licensee has performed a revised engineering calculation 86-0357 for the primary containment net free air space as a function of reactor water level.
Contained within is a revised RTD and Dewcell Volume Fraction Reassignment Algorithm correcting the problem. The inspectors reviewed the corrective action and found it to be acceptable.
3.
Containment Integrated Leak Rate Testing 3.1 General During the period October 25 through October 29, 1986, a periodic CILRT was performed at Oyster Creek Nuclear Generating Station, as required l
The test was conducted with the Cor tainment Isolation Valves (CIV's) and Containment Pressure Boundaries CPB's) in i
an "As-Left" condition. The "As-Found" test was previously caclared a failure by the licensee due to excessive local leakage.
The test was performed in accordance with station procedure 666.5.007
" Primary Containment Integrated Leak Rate Test," Revision D.
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The inspectors reviewed the test procedure and witnessed preparations and various portions of the "As-Left" CILRT.
The purpose of this inspection was to ascertain that the CILRT was conducted in compliance with the requirements and commitments refer-enced in the following sections, and that the test results met the acceptance criteria specified in the station procedures and Appendix J, 10 CFR 50. The procedures were reviewed for their technical adequacy to perform the intenced activities.
3.2 References Oyster Creek Nuclear Generating Station Technical Specifications
Section 4.5.
10 CFR; Part 50, Appendix J, Primary Reactor Containment Leakage
Testing for Water Cooled Power Reactors.
Final Safety Analysis Report (FSAR).
- ANSI /ANS 56.8-1981, Containment Systems Leakage Testing Require-
ments.
USNRC I&E Information Notice No. 85-71; Containment Integrated
Leak Rate Tests.
3.3 Documents Reviewed 666.5.007, Primary Containment Integrated Leak Rate Test,
Revision D.
665.5.020, Integrated Local Leak Rate Summary, Revision No.1.
- 125, Conduct of Plant Engineering, Revision 3 (Drywell Volume
Fraction Calculation).
Calibration Data for CILRT Instrumentation by Volumetrics.
- GPU Nuclear Maintenance and Construction Short Form (Work
Request).
Quality Assurance Monitoring Report 8610508.
- 3.4 Administrative Control of CILRT and Procedure Review The inspectors reviewed procedural sign-offs, the CILRT log, and the main control room and radwaste control room daily logs to verify that:
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Test directors were designated and their responsibilities were
clearly defined.
The procedures were adequately detailed to assure satisfactory
performance.
Test prerequisites were met.
- All systems required to maintain the plant in a safe condition
were operable and in their normal mode.
All required plant parameters were being recorded on at least
i an hourly basis.
3.5 Test Witnessing The inspectors witnessed portions of the following test activities:
(1) Pretest " Leak Chasing" by Licensee (2) Containment Atmospheric Stabilization (3) 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> CILRT Data Acquisition (4) 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Instrument Verification.
These activities were witnessed to verify that the CILRT was conduc-ted in accordance with the test procedure and within the regulatory requirements of 10 CFR 50, Appendix J.
Additionally, several para-meters were monitored by the inspectors during the course of the CILRT and are listed as follows: reactor vessel water level, CRD flow, drywell equipment drain tank pump discharge flow and drywell floor drain sump pump discharge flow.
The objective was to monitor the inventory of water in the reactor coolant system for prompt identification of leaks and to chase leak sources. A decrease in reactor vessel water level was observed between 7:50 p.m. on October 27, 1986 and 8:35 a.m. on October 28, 1986.
The test direc-tor stated that this change was due to plant operations and was not attributable toward a leak.
The summarized data on Table 1 indicates no meaningful changes.
3.6 Containment Inspection and Test Boundary Verification The inspectors conducted several tours independently and with licensee personnel before and during the CILRT. The containment was inspected for the existence of artificial boundaries and boundaries showing evidence of leakage.
Various valves and fittings were found to be leaking.
However, the licensee inspection team identified and secured the leakage sources before the commencement of the test in accordance with the station procedure.
No unacceptable conditions were identified.
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3.7 Test Instrumentation The inspectors reviewed the calibration records of the CILRT instru-mentation to ascertain that the instruments had been calibrated with-in the 6 month period prior to the test, as per the industry standard ANSI /ANS-56.8-1981.
The calibrations were traceable to the National Bureau of Standards. The inspectors also verified that the instru-ment system satisfied the specifications given in the instrument selection guide of ANSI /ANS-56.8-1981. The inspectors observed the operation of the automatic data collection system during the conduct of the test.
No unacceptable conditions were identified.
3.8 Failure of "As-Found" CILRT The "As-Found" integrity of the containment did not meet the acceptance criteria for total leakage. This is due to excessive leakage from CIV's.
The "As-Found" portion of the test was therefore declared a failure by the licensee. The local leak rate testing performed prior to the October,1986 CILRT identified (19) CIV's with leak rates in excess of the acceptance criteria of 12.08 SCFH at 20 psig. Of these (19) CIV's (15) were reported to have "offscale" leakage. The "As-Found" integrated leak rate is therefore unquantifiable.
In addition, the (19) failed CIV's involved containment isolation boundaries with in-series CIV's which both failed the acceptance criteria.
Of these (5) boundaries (4)
had in-series CIV's which both failed "offscale". This issue will be addressed by GPU as the subject of an LER, pursuant to 10 CFR 50.73,
" Licensee Event Report System". The inspectors had no further questions.
3.9 Chronology of Events for "As-Left" CILRT October 25, 1986 2:30 p.m.
Final reviews of precedure, volumetrics equipment and PCILRT software.
F.ID No. 2 inoperable.
4:50 p.m.
Operators briefed by test director on PCILRT activities and test procedure 666.5.007.
5:30 p.m.
Began containment pressurization.
5:52 p.m.
Dewcell No. 3 reading low. Monitoring for possible deletion.
5:56 p.m.
Entered new volume fraction for RTD's due to the inoperability of RTD No..
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October 26, 1986 1:30 a.m.
Declared Dewcell No. 3 inoperable and reweighted remaining Dewcells in the zone.
4:30 a.m.
Reached test pressure of approximately 22 psig.
4:45 a.m.
Isolated and removed pressure source from drywell.
5:00 a.m.
Advanced to " Stabilization Mode" in CILRT computer.
9:25 a.m.
Temperature stabilization requirements satisfied (Section 6.2 of 666.5.007).
10:20 a.m.
Type "A" test officially declared in progress by test director.
10:45 a.m.
Type "A" test failing. Began looking for leaks. The following leaks were discovered and repaired:
(1) Containment Spray System; V-21-17, V-21-15, V-21-5, all packing leaks.
Isolated DP transmit-ter on containment spray HX northside.
(2) Purge system; V-23-14 flange.
(3) V-38-1047 instrument valve fitting by rack RK03.
(4) Volumetrics cabinet air fitting.
5:53 p.m.
Of ficial restart of type "A" test.
8:40 p.m.
Leak rate is failing PCILRT.
9:38 p.m.
Leak rate is 0.7418*;/ day, still failing but beginning to trend down after tightening gland stem nuts on V-21-11 valve.
10:30 p.m.
I&C technician discovered excessive leakage on V-23-256. This is the supply line positioner valve for V-23-13 (N2 purge line). Test director instructed technicians to close this sensing valve and replace copper tubing going into the positioner.
10:45 p.m.
V-21-13, V-21-17 packing leaks, tightened packing.
Retightened flange on V-23-14.
Seated relief valves 21-21 and 21-22 for northside cont. spray H.
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October 27, 1986 1:00 a.m.
Assembled crews for leak chasing. All crews were dispatched and instructed to check pressure fittings, valve packings, stems, sensing lines, etc... with leak-tek or streamers to detect possible leakage.
Operations began flooding the drywell head seal cavity to check for leakage around the head.
3:00 a.m.
Results from leak rate crews:
V-28-18 packing leak (on top of torus)
Containment spray and core spray rooms - no leaks Trunnion room - no leaks Containment spray HX - no leaks Drywell head - no leaks T.I.P. room - no leaks 3:30 a.m.
Sent mechanics down on top of torus to tighten pack-ing on V-28-18.
4:30 a.m.
Found some leaks on compression copper tubing fitting for V-23-25 and V-23-259 on 23' El near scram dump volume.
Requested OPS maintenance to repair them.
Found packing leaks on 0 analyzer valves on 23' El
near drywell side entrance. All the valves with yellow handles are leaking.
Requested OPS maintenance to tighten packing on these valves.
7:30 a.m.
I&C technician found small packing leak on NSO4A MSIV.
7:50 a.m.
Have crews out leak chasing.
Presently not in offi-cial Type "A" test status.
2:35 p.m.
Tightened packing on purge valve V-28-18.
7:15 p.m.
Declared start of Type "A" test to have officially started at 5:32 p.m.
October 28, 1986 5:35 p.m.
Type "A" test completed, results satisfactory.
October 29, 1986 12:30 a.m.
Induced superimposed leak (2 SCFM) for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
Begin verification tes.
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4:30 a.m.
Verification test complete, results are satisfactory.
1:30 p.m.
Begin depressurizing containment.
3.10 Temperature Stabilization The containment atmosphere must meet the following criteria per station procedure 666.5.007:
"The primary containment will have reached temperature stabilization when the test pressure is reached and the latest rate of change of the weighted average contained air temperature averaged over the last hour does not deviate by more than 0.5 F per bour from the average rate of change of the weighted average contained air temperature averaged over the last four hours."
The inspectors independently calculated the stabilization criteria from the test data. The result is as follows:
(1) Average rate of change of the weighted average contained air temperature averaged over the last four hours = 0.345 F/HR.
(2) Latest rate of change of the weighted average contained air temperature averaged over the last hour = 0.153 F/HR.
(3) The deviation between the two averages is (0.345 - 0.153) F/HR
= 0.192 *F/HR.
This meets the criteria for temperature stabilization.
3.11 CILRT Results The CILRT leak rate was computed by the licensee using the mass point method (MPM) which was endorsed in ANSI /ANS-56.8-1981.
The accept-ance criteria for the test is as follows:
(1) Ltm < 0.75 L at 95% upper confident limit (UCL) for a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> g
reduced pressure test.
(2) The calculated leakage rate for the last 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test be less than 0.75 L.
(The 95% UCL may be disregarded for t
the final 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> criteria.)
Criteria No. 2 was imposed by the licensee this outage, to gain further confidence in the test results using the MPM.
The licensee stated that the addition of criteria No. 2 will show a change in the leak rate trend toward the end of the tes _
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Licensee results are as follows:
24 Hr. Test Last 8 Hrs.
Measured
.4209 Wt.%/ Day
.4773 Wt.%/ Day 95% UCL
.4282 Wt.%/ Day
Acceptable
.5921 Wt.%/ Day
.5921 Wt.%/ Day The results indicate a successful "As-Left" CILRT under MPM analysis as shown in figure 1.
The inspectors informed the licensee that the MPM of analysis is not presently endorsed in 10 CFR 50, Appendix J.
This item will remain as unresolved pending further clarification of the MPM (50-219/
86-35-01). The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test was followed by a successful (4) hour instrument verification test.
4.
Personnel Training and Qualifications The Qualification and training of selected test personnel were discussed with a licensee representative.
In addition the inspector evaluated the performance of test engineers during the test witnessing and reviewed their training and qualifications records.
The inspectors determined that the test engineers qualifications met the requirements specified in ANSI N 18.1-1971 " Selection and training of nuclear power plant personnel".
They were knowledgeable of their respon-sibilities and technical aspects of leak testing.
No unacceptable conditions were identified.
5.
QA/QC Coverage The inspectors discussed their coverage of the CILRT with a QA/QC repre-sentative and reviewed information concerning the QA/QC organization.
It was determined from the discussion that QA " monitors" observe surveillance testing and QC " monitors" observe maintenance and repair work.
The inspectors also reviewed selected QA/QC administrative and tracking and recording documentation.
Included in these were several " Quality Assurance Monitoring Reports" specific to CILRT. The reports were compre-hensive and orderly. The system for documenting findings and observations is well established. A QA " monitor" was present at the CILRT Data Center during the instrumentation verification test.
No unacceptable conditions were identifie,
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6.
Recurrent CILRT "As-Found" Failures The Oyster Creek containment has a history of repeated CILRT "As-Found" failures. The failures, due to recurrently excessive local leakage through CIV's have been incurred at Oyster Creek since the first periodic CILRT.
The situation has been repeated as follows: Upon completion of an operating cycle the containment "As-Found" leakage has been quantified and shown to be in excess of the acceptable "As-Found" limit; that is 1.0 L,.
Upon mainten-ance, acceptable "As-Left" leakage criteria for the containment has been met and restart of the plant for the next cycle may proceed.
Next outage CILRT
"As-Found" results however, indicate that containment isolation boundaries have again deteriorated. Therefore, the plant has been operated within bounds of the regulatory requirements ("As-Left" criteria is met at time of testing) but containment integrity has fallen below acceptable limits during plant operation.
This issue was discussed with the licensee at the October 29, 1986 exit meet-ing.
It was agreed that the failure of CIV's under local leak rate testing criteria has been the reason for the receated CILRT "As-Found" failures. The inspectors stated that although acceptable "As-Left" containment leak tight-ness has been restored during the fall 1986 outage; based on the licensee's history of CILRT failures there is little assurance that containment isolation boundaries will remain intact during the next operating cycle. The licensee then committed to initiate an intensive preventive maintenance (PM) program for CIVs.
The licensee further stated that a study would be done, based on the results of past LLRT's, to determine if a pattern of recurrent local
" leakers" exists.
The new PM program would be designed to improve overall containment integrity utilizing a systematic approach to CIV preventive maintenance. The new PM program will be implemented with the intention of increasing isolation boundary tightness sufficiently to maintain containment integrity through the next operating cycle.
7.
Exit Meeting Licensee management was informed of the purpose and scope of the inspection at the entrance interview. The findings of the inspection were periodically discussed and were summarized at the exit meeting on October 29, 1986.
Attendees at tne exit meeting are listed in Section 1 of this report. No written material was provided to the licensee by the inspector,..
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TABLE 1
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DW EQUIP. DRAIN DW FLOOR DRAIN SUMP-TANK PUMP DISCH.
PUMP DISCH. FLOW FLOW READING READINC INDICATES CILRT REACTOR VESSEL TOTAL CRD INDICATES IDENTIFIED UN sDENT;f LED -
DATE ar TIME PARAMETER LEVEL FIN.)
FLOW (GPM)
LEAKALE LEAKAGE 10-21-86/8:25 AM 166.7
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10-27-86/7:30 PM
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95767 265455 10-27-86/7:50 PM 167.6 31 ~
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10-28-86/8:15 AM 95772 2654>5 10-28-86/8:35 AM 162.8
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10-28-86/12:00 PM 95774'
265455
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10-28-86/3:35 PM 163.5
10-28-56/4:00 PM 95776s 265455
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10-28-86/8:00 PM 95778 265455
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