ML20129F682
| ML20129F682 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 07/01/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20129F647 | List: |
| References | |
| NUDOCS 8507170429 | |
| Download: ML20129F682 (5) | |
Text
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION O
WASHINCTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. ' 88 TO PROVISIONAL OPERATING LICENSE NO. DPR-16 f:Pil NUCLEAR CORPORATION AND JERSEY CENTRAL POWER & LIGHT COMPANY OYSTER CPEEK NUCLEAR GENEPATING STATION DOCKET NO. 50-219
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1.0 INTRODUCTION
Ry letter dated June 28, 1985, GPU Nuclear (the licensee \\ recuested an emergency amendrent to Provisional Operating License No. DPR-16 for the Oyster Creek Nuclear Generating Station (OCNGS). This amendment would authorize charges to Tables 3.13-1 and 4.13-1, Accident Monitoring Instrunentation, of the Appendix A Technical Specifications (TS) related to the backup relief valve resition indicator for each relief valve.
The changes will allow thermocouples (TE 65A and TE FFPI on the relief valve's corren discharge header to be whstituted for an inoperable thermoccuple (TE210-43V, W or X, and TE210-43Y or Z) irrediately downstrean of the relief valves which have uo-to-now been the on'y backup relief valve position i
indicators. The primary relief valve position indicator is an acoustic monitor.
At 3:00 p.m., Monday, Jure 74, 1985, a backup relief valve position indicator (TE210-43W) was declared ireperable due to low and erratic operation. This placed the 'acility in a TS limitin l
operetion (TS 3.13.A.2) which reouires GPU Nuclear (g condition forthe licensee) to return this thermocouple to operable status within 7 days or place the reactor in cold shutdown within the followino 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Because the thermocouple is located at the dischargo line of the relief valve inside conteinment, repair of the thermocouple would recuire a plant shutdown to enter the containment and repair the thermoenuple. The plant is at 100% power.
To avoid the transient condition of a shutdown and a subsequent restart, the licensee proposed an alternate means to maintain backup relief valve l
position indication using an existing thermoccup'c in each of the two common discharge headers from the five relief valves. TS 3.13.C will require the licensee to repair the inoperable thernoccuple " prior to startup following the next cold shutdown." The licensee's next scheduled cold shutdor-is October 1985.
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2.0' PACKGROUND INFORMATION By our letter dated September 13, 1979, > a h.cd requirements established as a result of our review of the Three Mile Island (Unit ?) accident to all operating r.uclear power plants. Certain of these requirements, designated Lessons Learned Category "A", included Section 2.1.3.a of
'NUREG-0578 riated July 1979, Direct Indication of Valve Position, s
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Our evaluation of the licensee's compliance with these Category "A" iters was attached to our letter to the licensee dated March 79, 1981, as part of Arendrent 54 which incorporated Tables 3.13-1 and 4.13-1 into the TS.
Subseouent to these actions, the licensee has experienced a 'tilure of a cor:ponent of the relief valve position indication system that, under present requirenents, will require the plant to shutdown for cre,tcirrent entry and repair of the component. The licensee has detemined that sufficient diverse instrumentation remains operable so as to nake this shutdown for repair unnecessary at this time.
3.0 EVALUATION
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Our requirenents for installation of a reliable position indicating system-for relief valves were based on the need to provide the operator 5-with a diagnostic aid to reduce the ambiguity between indications that might indicate either an open relief valve or a small line break.
Such a system did not need to be safety grade provided that backup nethnds of detemining valve position are available.
The licensee has proposed changes to TS Tables 3.13-1 and 4.13-1 to add requirements on existing thermocouples not previously referred to in these tables. These additional thermocouples are located downstream of the i
failed thermoenuple, in the relief valve discharge headers.
The purpose of this change recuest is to allow the thermocouples in the discharge headers to be utilized as backup indications of a stuck open relief valve. Although these tharrocouples do not provide a direct indication of a specific relief valve's position, when utilized with other existing instrumentation, they will provide positive confirmation of a l
specific relief valve's position status.
As the use o' these thermocouples provides an indirect indication of relief valve position, and thus does not exactly meet the criteria of NUREG 0578 for direct position indication, consideratice was not previously given to giving credit for their usage.
However, the licensee's recent analysis presented in its June 28, 1985, submittel indicates that they con be used to verify relief valve position, in a manner equivalent to that provided by the individual relief valve discharce line thermocouples. The relief valve position indicator backup thermocouple read out outside the control roon; the thermocouples on the corron discharge header read out in the control room.
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The licensee's amendment request describes the results of their analysis.
In their evaluation they note that, because the header thermocouples have not been previously used as substitutes for the relief valve backup indicator l
l thernoccuple, channel calibrations have not been performed on them. Because l
containment entry is required to do such a calibration, the licensee has proposed increasing the channel check frequency instead. Calibration of a thermocouple is meaningless because the gain is fixed. Thus calibration is only a check against an independent standard at several poirts instead of against similer devices at a single point. Consequently calibration of the "new" thermocouple is not required until the next plant cold shutdown.
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. In addition to consideration of the licensee presentation on this issue, the staff is in the process of publishing our Safety Evrluatiori (SE) en Reactor Vessel Water Level Instrumentation for this plant.
The sta'f has corcluded in that review that the density compensated fuel zone instruncrtetion providas ir:provements that reduce the level indication errors caused by high drywell tenperatures. There is also the instrumentation to indicate rising torus pool water temperature due to discharges from the relief valves.
Therefore, this instrumentation can be relied on te give an indication of loss of coolant through an open relief valve.
As a result of having determined the adecuacy of existing instrumentation for reactor vessel water level, containment temperature, and primary (acoustic) relief valve detectors; and having reviewed the licensee's eveluation of the proposed changes, the staff concluded that the propose 1 constitutes a change in location of a simple sensor and a relaxation of calibration requirements for the relocated sensor until the next plant cold s"
shutdown. Since analysis has shown that the proposed substituted thermocouples can be used to verify relief valve position in a manner eouivalent to that provided by the individual relief valve discharge line thermocouples, the staff concludes that the licensee's proposed cFenge is acceptable.
3.1 Findings of Emeroency Warranting An Amendnert Vithout Notice Without this amendment, the licensee will be required to shut down the plant on t'onday, July 1,1985. At 3:00 p.m., Monday, June 24, 1985, a backup relief I
valve position indicator (thermocouple TE210-43W) for one of the five relie#
l valves was declared inoperable due to a low and erratic indication. The staff had discussions with plant personnel on the inoperable thermocouple on June 25, 1985. The inoperable thermocouple is located at the discharge line of the relief valve inside containment and the receir of the thermocouple would require a plant shutdown to enter the drywell. The licensee contacted the staff on June 26, 1985, to discuss the licensee's proposal to amend the TS to provide for an ecreptable backup to tha inoperable thermocouple until the next cold shutdown when TS 3.13.C will require the licensee to repair the inoperable themocouole before restart from the cold shutdown. The licensee I
requested the proposed license amendment in its letter of June 28,108F.
The licensee stated in its letter dated June 28, 1985, that there had been no prior indication that the thermocouple's performance was questionable until its behavior was observed on Ponday, June 24, 1985. The tiRC Resident Inspector at Oyster Creek agreed with the licensee's characterization of the thermocouple's cuestionable performance.
The staff has reviewed the energency circumstances associated with the licensee's request and determined that, in accordance with 10 CFR 50.91(a)(5), a valid emergency situation exists. The staff believes that the licensee made a timely application and did not fail to seek this amendment earlier in order to create the emergency and take advantage of the energency provisions.
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, 3.2 Final No Sionificant Hazards Consideration Determination.
The relief valve position indication incorporated in the TS in Amendment 54 dated March 29, 1081, was to address TMI-2 Lessons Learned Category "A" requirement 2.1.3.a in NUREG-0578 dated July 1979. The staff's evaluation in its SE for Amendment 54 stated that its requirements for installation of a reliable position indicating systen for relief valves were based on the need to provide the operator with a diagnostic aid to reduce the ambiguity between indications that might indicate either an open relief valve or a
.small line break.
In its letter dated June 28, 1085, the licensee has stated that the existing thermocouple in each of the two comon discharge headers downstream of the relief velves has sufficient sensitivity to be a substitute for the inoperable backup relie# valve indicator thermocouple 4
.immediately downstream of its relief valve. The backup thermocouple is closer to the relief valve than the thermercuple in the common discharge header and would be more sensitive; however, the licensee states that header themoccuples should provide an indication of less than 0.1% of rated relief valve stean flev. The relief valve position indicator backup themocouples read out outside the control room; the themocouples on the comon discharge header read out in the control room.
In short, the common discharge beader themoccuples should provide backup relief valve position indication essentially equivalent to that provided by the now inoperable backup thermocouple which the common discharge header themocouple would replace.
(In addition to this header thermocouple, there is torus pool water temperature indication--the relief valves discharge to the torus pcol--and reactor water level indication in the control room. A significant loss of coolant through an open relief valve would be indiceted by rising torus pool water temperature and falling reactor water level until alarm setpoints were reached.) Therefore, authorizing the use of the comon discharge header themocouples as a substitute for an inoperable backup relief valve position indicator themocouple (1) does not involve a significant increase in the probability or consequences of a oraviously evaluated accident, (2) does not create the possibility of a new or different kind of accident from any accident previously evalurted and (3) does not involve a significant reduction in a margin of safety. Based on this, the staff concludes that the requested action does not irvelve a significant hazards consideration.
3.3 State Consultation In accordance with the Commission's regulations, consultation was held with the State of New Jersey, Bureau n' P.adiation Protection, by telephone on June 76 and July 1, 1985. The State of New Jersey expressed no concern over the licensee's proposed anendment.
No other comments were solicited or received. A notice of the proposed amendment was not published in the Federal Register due to the lack of sufficient time for public comment prior to the Monday, July 1, 1985, date when the amendment had to be authorized to prevent the plant from shutting down, l
4.0 ENVIRONMENTAL CONSIDERATION
i This anendrent involves a change in the installation or use of facility components located within the restricted area as defined in 10 CFP Part 20 and charces to the surveillance requirements. The staff has determined that the amendnent involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has made a final-finding that this amendnent involves no significant hazards consideratien. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFP 51.22(c)(9).
Pursuant to 10 CFP. 51.??(b) no environmental impact statement or environmental assessnent need be prepared in connection with the issuance '
of this amendnert.
5.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that:
(1) the amendment does not (a) significently increase the probability or consequences of an accident previously evaluated, (b) create the possibility of a new or different kind of accident from any previously evaluated or (c) significantly reduce e safety margin and, therefore, the amendment does not involve significant hazards considerations, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in conpliarce with the Comnission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
6.0 ACKNOWLEDGEMENT This Safety Evaluation has been prepared by R. Scholl and J. Donohew.
Dated: July 1, 1985
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