ML20211J689
| ML20211J689 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 10/27/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20211J681 | List: |
| References | |
| NUDOCS 8611110223 | |
| Download: ML20211J689 (4) | |
Text
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EETYEVALUATIONBYTHEOFFICEOFNUCLEARREACTORREGULATION SUPPORTING AMENDMENT N0. 110 TO PROVISIONAL OPERATING LICENSE NO. DPR-16 GPU NUCLEAR CORPORATION AND JERSEY CENTRAL POWER & LIGHT COMPANY OYSTER CREEK NUCLEAR GENERATING STATION DOCKET NO. 50-219 1.0. INTRODUCTION By letter dated September 5,1986, GPU Nuclear (the licensee) requested an amendment to Provisional Operating License No. DPR-16 for the Oyster Creek NuclearGeneratingStation(0ysterCreek). This amendment would authorize a revision to the footnote, marked with an asterisk "*", to Table 3.1.1, Protective Instrumentation Requirements, of the Appendix A Technical Specifications (TS). The licensee may, with this change, have one channel of a protective instrument function made~ inoperable for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, to conduct tests and calibrations of the protective instrumentation channels, as required by the TS, without tripping the channel's trip system.
2.0 DISCUSSION AND EVALUATION This amendment proposes to revise the period of time when a protective instrumentation channel listed in Table 3.1.1 of the TS may be made inoperable without tripping its associated trip system.
In the existing t
TS, these channels may be taken out of service to perform tests and calibrations for up to I hour per month without tripping the associated trip system. The proposed amendment would change that to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> but only for eac, required TS surveillance.
The frequency of TS-required surveillances is listed in Table 4.1.1 of the TS. The proposed amendment should be more restrictive than the existing TS for 22 out of the 27 separate parameter (e.g., drywell pressure, reactor water level low function, APRM level) channels listed in Table 4.1.1.
Each parameter channel is actually four separate and independent channels measuring the same parameter.
For these 5 channels, the instrumentation is only taken out of service for a small fraction (about 1/10) of an hour and, therefore, this amendment would not lengthen the time these channels could be out of service in a month without the associated channel trip system being tripped (Ref. 3).
These channels have built-in calibration equipment (3 channels) or the 8611110223 861027 PDR ADOCK 05000219 P
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l time needed to perform the necessary work is shorter than an hour per month (2 channels). These are the Average Power Range Monitor (APRM) level, scram trips, and rod blocks and the high radiation in the main streamline reactor building, and air ejector offgas (Ref.3).
The licensee states that it expects that the time needed for the analog trip system channels for reactor water low level and low-low level in the reactor protection system to be taken out of service for TS required tests and calibration and then returned to service is greater than an hour. Therefore, with the existing TS, every time each of these analog channel is taken out of service for TS-required tests and calibration, the channel may have to have its associated trip system be placed in the tripped condition while the channel is t
still.under surveillance. These analog channels result from a modification in the present outage to the reactor water level instrumentation system which replaced digital sensing devices with an analog trip system. Therefore, this situation did not exist before. This replacement is discussed in the staff's letter to the licensee dated August 22, 1981, on Amendment No. 95 and Static Ring switches.
The ch u nel performs its function by causing its associated trip system to trip in response to a safety setpoint being exceeded as, for example, high drywell pressure. A channel is tripped because it is inoperable, that is, not capable of actuating its associated trip system or because it is out-of-service too long and again is not capable of actuating its associated trip system. A
-channel is not tripped when it is taken out of service for tests or calibrations because putting it in the tripped condition increases the changes of spurious or inadvertent trips or scrams and thus unnecessary challenges to safety systems.
In addition, for channels which are operable prior to being taken out of service for tests or calibrations, there is no reason to believe the other channels are inoperable. Placing a channel in the tripped condition when it is inoperable also increases the chance of spurious or inadvertent trips or scrams but the fact the channel was inoperable may mean the other channels are more likely to be inoperable.
In addition, placing a reactor water level low-low function channel in the tripped condition causes all four core spray pumps to unnecessarily start up.
This channel is one of the analog channels discussed above. The proposed amendment would prevent. starting up these pumps during required TS surveillance.
on these channels.
Surveillance testing is necessary to provide a high degree of reliability for the automatic actuation circuits of the protective instrumentation. To test the actuation circuit completely, it must be made inoperable but it does not have to have its associated trip system tripped. Tripping the channel rather than just making it inoperable during the required surveillance testing increases
st the likelihood of spurious scrams or unnecessary challenges to safety systems. The licensee has stated that, given the tested reliability of the operational instrumentation, an increase in out of service time from I hour to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> will have a negligible effect on the channel failure rate. The staff agrees.
Conservatively, the typical increase for a channel could be from I hour per month to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per month which is an increase of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> per year or 0.137% per year. The worst increase is for one channel and-is an increase of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> per 3 days or 122 hours0.00141 days <br />0.0339 hours <br />2.017196e-4 weeks <br />4.6421e-5 months <br /> per. ;/ var. This is an increase of 1.39% per year. These are worse case estimates because the actual time the channel may be out-of-service for TS tests and calibrations should be less than the 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The worse case is not realistic because, as described above, the 5 channels where the proposed amendment could.be considered less restrictive, the amendment in fact does not lengthen the out-of-service time for TS surveillance for these channels.
The Standard Technical Specifications for General Electric Boiling Water Reactors (BWR-STS), NUREG-0213, Revision 3, specifies a 2-hour limit for TS required surveillance. This is in footnote (a) to Table 3.3.1-1, Reactor Protection System Instrumentation, on page 3/4 3-5 of the BWR-STS. This table is applicable to Oyster Creek. Therefore, the licensee's proposed amendment is in agreement with the BWR-STS.
The staff has reviewed and evaluated the licensee's proposed amendment dated September 5, 1986. Based on the above, the staff concludes that the proposed change to Table 3.1.1 is acceptable.
The licensee also proposed a change to the Bases for TS Section 3.1.
This change has the' Bases state the same as the proposed footnote "*" to TS Table 3.1.1.
The change removes the basis for the existing requirement of one hour per month from the Bases for Section 3.1.. Therefore, this change is acceptable to the staff.
3.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change to a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and a change to the surveillance requirements. The staff has determined that the amendment 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 previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, this amendment 1
meets the eligibility criteria for categorical exclusion set forth in 10CFR51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement nor environmental assessment n'eed be prepared in connection with
- the issuance of this amendment.
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4.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security nor to the health and safety of the public.
5.0 REFERENCES
1.
Letter from P. B. Fiedler (GPUN) to J. A. Zwolinski (NRC), TSCR 153, dated September 5, 1986.
2.
Standard Technical Specifications for General Electric Boiling Water Reactors (BWR/5), NUREG-0123, Revision 3, dated Fall 1980 3.
Phone conference between J. Donohew (NRC) and J. Rogers (GPllN) on October 6, 1986.
Principal Contributor:
J. Donohew Dated: October 27, 1986
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