ML20237B040
| ML20237B040 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 12/08/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20237B030 | List: |
| References | |
| TAC-66377, NUDOCS 8712150425 | |
| Download: ML20237B040 (4) | |
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.105 TO FACILITY CPERATING LICENSE NO. NPF-3 TOLEDO EDISON COMPANY AND THE CLEVELAND ELECTRIC ILLUMINATING COMPANY DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 I
DOCKET NO. 50-346
1.0 INTRODUCTION
By letter dated October 9, 1987, Toledo Edison Company (TED or the licensee) requested a change to Facility Operating License No. NPF-3, Appendix A Technical Specifications (TSs), for the Davis-Besse Nuclear Power Station, Unit No. 1.
The changes proposed would permit extension of certain surveillance requirements, one of which would otherwise be required to be performed as early as December 10, 1987. Specifically, the extension would extend the surveillance due dates for Emergency Diesel-Generators 1-1 and 1-2 (EDG 1-1 and EDG 1-2) from January 3, 1988 and December 10,_1987 to March 31, 1988 and March 20, 1988, respectively.
The surveillance extended by the proposed amendment are (1) subjecting the EDG to an inspection in accordance with the manufacturer's recommendations and (2) simulating a loss of offsite power in conjunction with a safety injection actuation signal as required by Surveillance Requirement 4.8.1.1.2.d.1 and 4.8.1.1.2.d.3.(c).
In addition to the extensions discussed above, the licensee proposed a change in Specification 4.8.1.1.2.d.3 to correctly refer to the safety features actuation system (SFAS) test signal vice the safety injection actuation test l
signal.
DISCUSSION Surveillance Requirement 4.8.1.1.2.d.1 requires subjecting each (EDG) diesel to an inspection which is in accordance with procedures prepared in conjunction l
with the manufacturer's recommendations for this class of standby service.
Surveillance Requirement 4.8.1.1.2.d.3.(c) requires simulating a loss of offsite power in conjunction with a safety injection actuation test signal (safety features actuation system test signal), and verifying that all EDG. trips, I
i except overspeed and generator differential, are bypassed automatically upon loss of voltage on the essential bus and/or an SFAS test signal.
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1 The surveillance discussed above must be performed at least once each eighteen months.
Specification 4.0.2 requires the performance of each Surveillance Requirement within the specified time interval, however, any one interval is allowed to be as much as 1.25 times the specified surveillance interval, and the combined interval for any three consecutive surveillance is allowed to be as much as 3.25 times the surveillance interval.
Surveillance Requirements 4.8.1.1.2.d.1 and 4.8.1.1.2.d.3 must be performed no later than January 3,1988 and December 10, 1987 for EDG 1-1 and EDG 1-2 respectively, to comply with Specification 4.0.2.
To perform the scope of work necessary to satisfy Surveillance Requirement 4.8.1.1.2.d.1, TED has estimated that the diesel would be inoperable for a period of approximately two weeks. This exceeds the 72-hour action statement of Specification 3.8.1.1 for one inoperable diesel while the plant is in Modes I through 4, and, therefore, the plant would have to be shut down.
TED has stated that the tests necessary to satisfy Surveillance Requirement 4.8.1.1.2.d.3 are normally performed in conjunction with the EDG inspection discussed above or with the integrated SFAS test done during a refueling outage.
The licensee further stated that it is not desirable to conduct this test while the plant is operating at power, and that conducting this test in Modes 5 or 6 provides a higher level of confidence of circuit operability because the bypassed trips can be verified during a condition where the EDG is the sole source of power to the essential 4160 V bus during the integrated SFAS test.
2.0 EVALUATION The 18-month test interval for the EDGs was selected to be consistent with the maximum anticipated interval between refueling outages and is based on engineering judgment to achieve the dual goals of the need to conduct periodic surveillance tests but not interfere substantially with unit availability.
The tolerances on the individual and consecutive intervals are intended to ensure that the reliability associated with the surveillance activity is not likely to be significantly degraded beyond that obtained from the nominal specified interval.
In its application, TED asserts that a review, performed by the EDG vendor, of the diesel operating history and projected operation until the proposed inspections in March 1988 (if the extension is granted) has allowed the vendor to state that the EDG inspection required by Specification 4.8.1.1.2.d.1 can be extended to 26 months from 18 months on a one-time basis, provided that specific components be inspected on each EDG.
These inspections are based on the vendor's field service experience.
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. l TED asserts that the results from the EDG surveillance and trend analysis programs show that the individual performance of the Davis-Besse EDGs exceeds the performance standard proposed in NRC Generic Letter 84-15 (July 2, 1984),
and that the combined performance surpasses the industry average.
Only two failures to start in the last 100 starts have occurred on EDG 1-1 and no failures have occurred on EDG 1-2.
TED also asserts that there have been no significant operational problems with the essential or nonessential trip functions.
TED is requesting an extension to the current due dates for the surveillance discussed above of 88 days for EDG 1-1 and 101 days for EDG 1-2.
This extension would permit the unit to continue operation at power until the scheduled refueling outage in mid-February 1988.
However, TED has committed to performing the required surveillance if an unscheduled outage requires the plant to enter Modes 5 or 6 prior to the refueling outage for a period of time longer than 2 weeks.
As compensatory measures, TED also has committed to (1) perform the vendor-identified inspections on specific EDG components prior to the current due date for Surveillance Requirement 4.8.1.1.2.d.1, and (2) continue to perform a monthly test per Surveillance Requirement 4.8.1.1.2.d.4 even though such a test is required by Technical Specifications only every 18 months.
The extensions of no more that 88 and 101 days will not increase significantly the probability of undetected degradation of the EDGs based on previous operating history.
TED has indicated that the previous 18-month inspection indicated no unusual wear of components recommended by the EDG vendor for inspection.
TED has also proposed correction of a typographical error in Surveillance Requirement 4.8.1.1.2.d.3 by replacing reference to "... safety injection actuation test signal..." with "... safety features actuation system (SFAS) test signal...".
This change would merely correctly identify the test signal and has no effect upon the safe operation of the facility.
3.0 FINDINGS Based upon the details discussed above and the compensatory measures committed to by TED, the NRC staff has concluded that the proposed extensions of no more than 88 and 101 days are acceptable.
The staff also concludes that the correction of the typographical error is acceptable.
4.0 ENVIRONMENTAL CONSIDERATION
This amendment involves changes to a surveillance requirement.
We have 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 meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement nor environmental assessment need be prepared in connection with the issuance of this amendment.
- 5. 0 CONCLUSION l
l We have 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 the security nor to the health and safety of the public.
Prinicipal Contributor:
A. De Agazio Dated: December 8, 1987 i
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