ML20247Q584
| ML20247Q584 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 05/30/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20247Q578 | List: |
| References | |
| GL-84-15, NUDOCS 8906060472 | |
| Download: ML20247Q584 (5) | |
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l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 77 TO FACILITY OPERATING LICENSE NO. NPF-12 SOUTH CAROLINA ELECTRIC & GAS COMPANY SOUTH CAROLINA PUBLIC SERVICE AUTHORITY VIRGIL C. SUMMER NUCLEAR STATION. UNIT h0. 1 DOCKET NO. 50-395
1.0 INTRODUCTION
'By letter dated June 10, 1985 South Carolina Electric & Gas Company (SCE&G) requested changes to the Technical Specifications. (TS) for the' diesel generators (Section 3/4.8.1, AC Sources) at the Virgil C. Summer Nuclear Station, Unit No. 1.
Based on staff comments and requests for additional infomation, SCE8G revised their original submittal in letters dated December 6,1985 May'16, 1988, July 14, 1988, July 28, 1988 and November 18, 1988 and April 5, 1989.
In Amendment No. 50 to Facility Operating License NPF-12, the staff approved those portions of the technical specification changes that related to the reduction of the number of diesel generator cold fast starts as called for in Generic Letter 84-15, " Proposed Staff Acticns to Improve and Maintain Diesel Generator Reliability." The staff also approved administrative changes to regroup the surveillance requirements to clarify the requirements and increase their useability.
The staff stated in its Amendment No. 50 Safety Evaluation (SE) that the remaining portion of the TS changes were still under review and would be addressed at a later date. The following evaluation addresses those remaining portions of the TS changes.
2.0 EVALUATION
(a) The proposed changes regroup the Action statements in Section 3.8.1.1 to clarify the requirements and increase their usability.
The staff has reviewed these administrative changes to the TS and finds them acceptable.
(b) Action statement 3.S.I.1.a.2 deletes the requirement to demonstrate the diesel generators operable for loss of an offsite circuit provided they a
have been successfully tested within the past 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The staff find this change reduces unnecessary testing and, thereby, the associated detrimental i
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effects of frequent starts and is, therefore, acceptable.
also in accordance with previously approved TS on North Anna.This change is (c)
Action statements 3.8.1.1.a.2, b.2, c.2, and d.1 expand the length of time allowed to demonstrate a diesel generator operable from I hour in all cases, to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> for the loss of two power sources (offsite or onsite) and 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for the loss of one power source.
The require-ment to retest at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is also eliminated.
The staff finds these changes provide sufficient time to perform an orderly start test on the DGs, reduce unnecessary testing and thereby the associated detrimental effects of frequent starts and are therefore acceptable.
These changes are also in accordance with the guidance in Generic Letter 84-15 and with previously approved TS on North Anna.
(d)
Action statements 3.8.1.1.a.b.2 and c.2 eliminate the need to demonstrate the operability of a diesel generator when its redundant counterpart is inoperable due to preplanned testing or maintenance. The staff finds that this change reduces unnecessary testing and thereby the associated detrimen-tal effects of frequent starts and is, therefore, acceptable.
This change is also in accordance with previously approved TS on North Anna.
(e)
A footnote has been added to Action statements 3.8.1.1.b.2 and c.2 that requires that surveillance testing on a redundant diesel generator be completed regardless of when the inoperable diesel generator is restored to operability. The staff finds that this change ensures that both diesel generators are tested for common-mode failures which may have caused the initial inoperability of the first diesel generator. This change is acceptable and in accordance with previously approved TS on North Anna.
(f) In Surveillance Requirements 4.8.1.1.2.a.4 and 4.3.1.1.2.d.2, the diesel generator loading requirements have been specified as an indicated loading band which extends up to the continuous rating of the diesel generator (e.g., "an indicated 4150-4250 kw" for the continuous rating of 4250kW The diesel generator loading requirements in these surveillance were ).
originally specified as " greater than or equal to 4250 kW."
A new footnote has also been added to the loading band specified in these Surveillance Requirements which reads:
"This band is meant as guidance to avoid routine overloading of the engine. Loads in excess of this band shall
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not invalidate the test." The staff has found that the open-ended i
language " greater than or equal to" that exists in the present technical l
specification has the potential for routine overloading of the diesel generators.
The open-ended load requirement creates a situation wherein operators will tend to operate the diesel generators at a load for which the meter ir,dicates a value greater than the specified value in order to atoid an enforcement action for an invalid test if the meter indication j
should slip below the specified value.
Because routine overloading of the diesel generators should be avoided, and because the loading band i
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, utilized is sufficiently narrow to ensure the machines are nominally loaded to their continuous rating, the staff finds these changes acceptable.
The staff has also approved this type of change on North Anna and on near-terin operating license reviews.
(g) In Surveillance Requirement 4.8.1.1.2.e.2, the value of the load that must be rejected by the diesel generator has been changed from 830kW to 729kW.
The purpose of this surveillance is to demonstrate.that the diesel gener-ator can reject a load equal to'the value of:the largest single emergency load while maintaining voltage and frequency within the specified band.
As listed in the Virgil C. Summer Nuclear Station Final: Safety Analysis.
Report Table 8.3-3 (Channel A), the largest load is 729kW and is associ-ated with the charging pump.
Therefore, the staff considers this change acceptable.
(h) In Surveillance Requirement 4.8.1.1.2.e.7, the various requirements'of the surveillance have been separated into individual steps to improve clarity and useability.
.This administrative change is acceptable.
In addition, the loading of the diesel generator to its continuous rating which is presently required to be " greater than or equal to 4250kW" is now speci-fied to be a loading band of "4150.-4250kW**". Also, the loading of the diesel generator to its overload rating which is presently required to be
" greater than or equal to 4676kW" is now specified as "an indicated target value of 4676kW (between 4600-4700kW**)". The footnote associated with these loading bands is the same as that previously described in item (f) above.
The' staff finds the use of loading bands in this surveillance requirement is acceptable for the reasons discussed in item (f). In addition to the above changes -revised Surveillance Requirement 4.8.1.1.2.e.7 adds a provision to load the diesel generator to its continuous rating until engine temperature equilibrium has been established prior to loading it to its overload rating.
This change is in accord with the provisions of NRC Regulatory Guide 1.9 and is therefore acceptable.
(1) In the first footnote to Table 4.8-1 of the existing Summer TS, the discussion on the 14 consecutive reliability tests states that, " Ten of these tests shall be in accordance with Surveillance Requirement 4.8.1.1.2.a.3...." SCE&G has taken the present start and load surveil-lance (4.8.1.1.2.a.3) and separated it into a separate start surveillance (4.8.1.1.2.a.3)andseparateloadsurveillance(4.8.1.1.2.a.4). The subject footnote was revised to read " Ten of these tests shall be in accord-ance with Surveillance Requirements 4.8.1.1.2.a.3 and 4.8.1.1.2.a.4....",
The staff finds this change to the footnote acceptable, j)
In the A.C. SOURCES, SHUTDOWN section of the proposed TS, a footnote, has been added to Limfting condition for Operation (LCO), 3.8.1.2.b.
The footnote reads, "ESF Load Sequencer may be deenergized in Mode 5 and 6."
The LCO that the footnote applies to requires that one diesel cenerator be operable in mcdes E ard 6.
The addition of the footnote allows the load i
sequencer associated with tn~ at diesel generator to be inoperable in modes 5 and 6.
In their original submittals SCE&G stated that, because the signals
that automatically start the diesel generator are not required to be operable in modes 5 and 6, to be consistent, this footnote is necessary to provide clarification for the determination of the diesel generator's operability in modes 5 and 6.
The staff however was concerned that deenergization of the load sequencer without deactivation of the corresponding loss of power relays could result in abnormal response of the diesel generator to certain loss of power events. For instance, it appeared from review of the load sequencer and diesel generator breaker legic diagrams in the Summer SAR, that a trip of the offsite power breaker with the load sequencer deenergized and loss of power relays operable would result in the diesel generator picking up the previously energized loads as a block rather than sequentially.
In order to prevent this kind of occurrence, the original proposal for the footnote should have read something to the effect that, "ESF Load Sequencer may be d6 energized in Modes 5 and 6 provided the loss of voltage and degraded vcitage relays are disabled". The staff discussed this concern with SCE&G and in an April 5, 1989 submittal, SCE&G proposed the above mentioned footnote to TS 3.8.1.2.b.
The staff has reviewed the proposed' change and finds it acceptable.
(k) Existing surveillance requirement 4.8.1.2 stipulates that the A.C. elec-trical power sources required in the shutdown mode "be demonstrated operable by the performance of each of the Surveillance Requirements of 4.8.1.1.1, 4.8.1.1.2 (except for requirement 4.8.1.1.2.a.4) and 4.8.1.1.3."
The licensee had proposed, prior to their April 5,1989 submittal, that the surveillance requirement be changed to nad "...be demonstrated OPERABLE by the performance or verification of each...(with the exception of 4.8.1.1.2.a.4) and...." The staff reviewed the proposed change and determined that the addition of the terminology "or verification" did not alter the meaning or intent of of the present surveillance require-ment nor did it enhance the surveillance requirement in any manner. The surveillance requirements associated with this proposed change, (4.8.1.1.1, 4.8.i.1.2, and 4.8.1.1.3) contain numerous instances where the action to be teken begins with the term " verifying". Modifying the existing surveil-lanw requirement to add "or verification" seemed unnecessary. Therefore, the :icensee modified the propcsed surveillance requirements 4.8.1.2 to delete the terminology "or verification".
SUMMARY
The i,taff has reviewed the portions of the SCE&G requested changes to the diesel generator technical specifications at Summer not previously reviewed under Amendment No. 50 to facility Operating License NPF-12, and finds them acceptable.
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3.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes 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 off site, and that there is no significant increase in individual or cumulative occupational radiation exposure.
issued a proposed finding that this amendment involves no significantThe hazards consideration, and there has been no public coment on such finding.
Accordingly, this amendment meets the eligibility) criteria for exclusion set forth in 10 CFR Section 51.22(c)(9.
Pursuant to 10 CFR 51.22(b) need be prepa, red in connection with the issuance of this amend
4.0 CONCLUSION
The Comission has issued a " Notice of Consideration of Issuance of Amendment to facility Operating License and Proposed No Significant Hazards Consideration Determination and Opportunity for Hearing" which was published in the FEDERAL REGISTER on July 17 1985 (50 FR 29016),
June 4, 1986 (51 FR 20373), August 1989 (54 FR 18055) and consulted with the State of South Caro No public comments or requests for hearing were received, and the State of South Carolina did not have comments.
The staff has concluded, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the that:
public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comission'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.
Principal Contributors:
J. Lazevnick J. Hayes Dated: 'May 30, 1989 I
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AMENDMENT NO,I 77 TO FACILITY OPERATING LICENSE NO.' NPF SUMMER. UNIT NO.:1' DetGEPfle j
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G. Lainas E.- Adensam P.' Anderson J. Hayes.
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W. Jones (P-130A)
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J. Lazevnick (8020 ACRS(10)
GPA/PA ARM /LFMB cc:. Licensee / Applicant Service List
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