ML20205Q608
| ML20205Q608 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 03/31/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20205Q605 | List: |
| References | |
| TAC-61607, TAC-64095, NUDOCS 8704030580 | |
| Download: ML20205Q608 (3) | |
Text
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'o UNITED STATES E'
NUC, LEAR REGULATORY COMM!SSION e
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.,E WASHINGTON, D. C. 20! 25
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING Af'ENDMENT NO.
31 TO FACILITY OPERATING LICENSE NO NPF-29 MISSISSIPPI POWER & LIGHT COMPANY SYSTEM FHERGY RESOURCES. INC.
SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION GRAND GULF NUCLEAR STATION UNIT 1 DOCKET NO. 50-416
1.0 INTRODUCTION
By letter dated May 28, 1986 as amended November 11, 1986 and February 13, 1987, Mississippi Power & Light Company, (the licensee)* requested an amendment to Facility Operating License No. NPF-29 for the Grand Gulf Nuclear Station, Unit 1.
The proposed amendment would: (1) change the wording to indicate only one drywell airlock; (2) rearrange Action Statement "a" to clarify that all actions in the statement are parts of the same action; (3) change the drywell overall airlock leakage test frequency from the present, once per six months, to each cold shutdown if notperformedwithintheprevioussixmonths;(4)changethesurveillance requirement regarding the verification that only one door in the airlock can be opened at a time from once per six months to once per 18 months; and (5) change the drywell air lock inflatable seal pressure instrumen-tation channel functional test from once per 31 days to once per 18 months.
2.0 EVALUATION l
1 Proposed change (1) involves the clarification of the wording in the l
Limiting Conditions for Operation, Surveillance Requirements and Bases of l
TS 3/4.6.2 "Drywell Integrity". Since the drywell contains only one l
personnel airlock, the present TS wording, which indicates more than one
(
airlock, does not accurately describe the as-built equipment. The proposed change is, therefore, acceptable.
Proposed change (2) (combination of parts 1, 2, and 3 of TS 3.6.2.3 Action Statement a. into one statement) is proposed to eliminate the possibility of misinterpreting the current TSs as three independent actions, whereas, they are intended to be three parts of the same action statement. The j
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- 0n December 20, 1986, the Commission issued License Amendment No. 27 which authorized the transfer of control and performance of licensed activities from Mississippi Power & Light Company to System Energy Resources, Inc.
(SERI). "The licensee" refers to Mississippi Power & Light Company before December 20, 1986 and to SERI on or after December 20, 1986.
8704030500 e7o333 DR ADOCK 05000416 PDR
2-chance would make the Grand Gulf TSs consistent with the TSs of other BWR plants. Proposed change (2) does not modify the actual action requirements and, therefore, is acceptable.
Proposed change (3) (decreasing the frequency of airlock leakage tests required by TS 4.6.2.3.b.1) would allow airlock leakage tests to be performed each cold shutdown, if not performed within the previous six monti.s. As presently written, this test may be required when the plant is at power and, consequently, woulo require work in a high radiation area.
This test is needed to ensure that the maximum leakaae which could bypass the suppression peol during an accident would not result in the containment exceedino the design pressure of 15.0 psig. The drywell airlock is one of the potentie.1 bypass leakage paths. The six-month surveillance requirement has been traditinr. ally associated with primary containment to which Appendix J applies. The drywell of Mark III plants is net primary contairment. There are other independent means for assuring airlock operability. Surveillance Requirement 4.6.2.3.d requires the airlock door inflatable seal system to be operable. Surveillance Requirement 4.6.2.3.c assures that only one door in the airlock can be opened at a time. Only one closed door in the airlock is required to maintain the integrity of the drywell. Surveillance Requirement 4.6.2.3.a assures door stels are secured after each opening. Furthermore, by allowing the airlock leakage test during cold shutdown, personnel exposures in a hioh radiation area are minimized. This proposed change would also make the Grand Gulf TSs consistent with the TSs of other BWR-6 plants. For the reasons cited above, the proposed char.ge is acceptable.
1 Proposed change (4) would extend the surveillance interval in Surveillance Requirement 4.6.2.3.c from six months to 18 months. This surveillance requirement deals with the verification that only one door in the drywell airlock can be opened at a time so that integrity of the drywell is assured while the plant is in operation. During operation above 5% power, drywell entry is not allowed by an administrative procedure. This makes the frequency of personnel entry into the drywell extremely small when at pcwer. Every 18 months, the licensee will assure that the airlock doors are properly operating as required by the proposed TS change. Therefore, the requested change is acceptable. Other BWR-6 plants have a similar requirement.
Proposed change (5) would increase the surveillance interval in Surveil-lance Requirement 4.6.2.3.d.1.(a) from the current 31 days to 18 months for the inflatable seal pressure instrumentation channel functional test.
Inflatable seals are on each airlock door to ensure a leak tightness of the doors. The purpose of the inflatable seal pressure instrumentation is to provide a signal to local indicating lights and also provide a permissive for the hydraulic door operating system. These lights provide personnel entering one door of the airlock with an indication that the other door is properly sealed. A mechanical interlock exists which prevents the opening of both doors simultaneously. The drywell airlock
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- inflatable seal pressure instrumentation activates no control room status lights or alarms and, thus, serves no function in warning of drywell integrity violation in the control room. There are other means to verify seal integrity and mechanical interlock. TS 4.6.2.3.d verifies seal air flask pressure once per seven days, and provides for a seal leakage test once per 18 months. Airlock door Surveillance Requirement 4.6.2.3.c ensures that only one door in the airlock can be opened at a time. During plant operation above 5% power, drywell entry is not allowed by procedure and therefore the infle. table seal pressure instrumentation is not needed
- for a personnel entry. This proposed change has also been implemented at other operating SWR-6's with similar instrumentation arrangements. For the reasons cited above, the requested change is acceptatie.
3.0 ENVIROFEENTAL CONSIDEPATION This arendment 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 changes to the surveillance requirements. The staff has determined that the amendment involves no significant increase in the amounts, and no significant charge 1.n the types, j
of any effluents that may be released offsite and that there is no signiff-l cant increase in individual or cumulative occupational radiation exposure.
l The Core.tssion has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public coment on such finding. Accordingly, this amendment meets the eligibility criteria for cateoorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to10CFR51.22(b),noenvironmentalimpactstctementorenvironmental assessment need be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
The Commission made a proposed determination that the amendment involves no significant hazards consideration which was published in the Federal Recister (52 FR 5861) on February 26, 1987, and consulted with the state of Mississippi. No public comments were received, and the state of Mississippi did not have any comments.
i The staff has concluded, based on the considerations discussed above, that: (1) there it 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 reoulations 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.
Principal Contributor:
Sang Bo Xiu, Plant Systems Branch, DBL Dated:
March 31,1987
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