ML17221A522

Proposed Tech Specs Re Surveillance Requirements for MSIVs & Main Feedwater Isolation Valves

ML17221A522
Person / Time
Site:	Saint Lucie
Issue date:	11/16/1987
From:	FLORIDA POWER & LIGHT CO.
To:
Shared Package
ML17221A521	List: ML17221A520 ML17221A522
References
NUDOCS 8711230373
Download: ML17221A522 (13)

Text

ATTACHMENT I Marked-up Technical Specification Pages 3/4 7-9 3/4 7-IO 87i 1230373 87iiih

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PLANT SYSTEMS MAIN STEAM LINE ISOLATION VALVES LIMITING CONDITION FOR OPERATION

3. 7. l. 5 Each main steam line isolation valve shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3 and 4.

ACTION:

MODE 1 With one main steam line isolation valve inoperable but open, POWER OPERATION may continue provided the inoperable valve is restored to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />; otherwise, be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

MODES 2, 3 - With one main steam line isolation valve inoperable, and 4 . subseqent operation in MODES 2, 3 or 4 may proceed provided

a. The isolation valve is maintained closed.

b. The provisions of Specification 3. 0. 4 are not applicable.

Otherwise, be in at breast HOT STANDBY within the next 6 hours and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

SURVEILLANCE RE UIREMENTS by~

4.7. 1.5 Each main steam line isolation valve shall be demonstrated OPERABLE ye,'P~, Jul( elcsunecs'8'ss n.yn'.cecssIs cslen kcskd p<<ns css+ T'ss 0pcgmA <

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LUCIE - UNIT 2 3/4 7-9

.r PLANT SYSTEMS MAIN FEEDWATER LINE ISOLATION VALVES LIMITING CONDITION FOR OPERATION 3.7.1.6 Each main.feedwater line isolation valve shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTION:

MODE 1 With one main feedwater line isolation valve inoperable but open, POWER OPERATION may continue provided the inoperable valve is restored to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />; otherwise, be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

MODES 2, 3 - With one main feedwater line isolation valve inoperable, and 4 subseqent operation in MODE 2, 3, or 4 may proceed provided:

."a. The isolation valve is maintained closed.

b. The'provisions of Specification 3. 0. 4 are not applicable.

Otherwise, be in at least HOT STANDBY within the next 6 hours and in COLD SHUTDOWN w'ithin the following 24 hours.

SURVEILLANCE RE UIREMENTS by~

4.7.1.6 Each main feedwater line isolation valve shall be demonstrated OPERABLE ST. LUCIE " UNIT 2 3/4 7-10 Amendment No. B

ATTACHf'1EHT 2 EVALUATION DESCRIPTION OF CHANGE l pl A change is proposed to revise Technical Specifications 4.7.1.5 and 4.7.1.6 on the 'surveillance requirements for the main steam isolation valves (MSIVs) and main feedwater isolation valves (MFIVs), respectively. The proposed amendment consists of three parts: (1) revising the MSIV closure time from 5.6 seconds to 6.75 seconds', (2) rewording, the surveillance frequency phrases for the MSIVs to use standard Technical Specification terminology and to eliminate duplication, and (3) similarly rewording the surveillance frequency phrases for the MFIVs. The proposed change of the MSIV closure time is needed to resolve a discrepancy between Surveillance Requirement 4.7.1.5.b and Table 3.3-5 parts 3.f and 6.b of the Technical Specifications based on the input values used in the "stretch" power safety analysis. The latter two proposed changes are needed to eliminate duplication between the Technical Specifications and the Inservice Testing (IST) Program and to adapt a standard terminology for the affected valves'urveillance frequencies. The proposed change to the MSIV closure time given in Surveillance Requirement 4.7.1.5 was discussed in Florida Power & Light Company (FPL) letter L-87-227 dated June 9, 1987 from C 0 Woody to the NRC. The changes relating to the surveillance frequency terminology are included as administrative changes.

DISCUSSION The safety evaluation discussion is broken down into two parts: (1) addressing the proposed change to the MSIV closure time and (2) addressing the wording on both the MSIV and MFIV surveillance frequencies. Each of these is discussed below.

The MSIV closure time requirement given in Technical Specification 4.7.1.5.b currently reflects the valve stroke time only, 5.6 seconds. The MSIV response times given in Table 3.3-5 parts 3.f and 6.b reflect the total of instrument response time, 1.15 seconds, plus the valve stroke time of 5.6 seconds. The proposed amendment would revise Technical Specification 4.7.1.5 to show the MSIV closure time as a total of the instrument response time plus the valve stroke time of 6.75 seconds.

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EVALUATION DISCUSSION (continued)

By letter L-84-148 dated June 4, 1984, FPL submitted a revised safety analysis to justify "stretch" power operation (operation at 2700 MWt rather than 2560 MWt). In the main steam line break (MSLB) analysis, it was necessary to assure that the MSIVs close within a certain time limit once the MSIV closure initiating condition is reached (high containment pressure or low steam generator pressure). This serves to minimize the positive reactivity effects of the Reactor Coolant System Cooldown associated'with the blowdown and to limit the pressure rise within the containment in the event the steam line rupture occurs within the containment.

The "stretch" power MSLB accident analysis assumed a time limit for MSIV closure of 6.75 seconds which includes both instrument response time and valve stroke time. As long as full valve closure of the MSIVs is accomplished within 6.75 seconds, regardless of the instrument response time and valve stroke time individually, the "stretch" power accident analysis is upheld.

This logic is applied when the ability of the MSIVs to isolate in 6.75 seconds is verified in accordance with Surveillance Requirement 4.3.2.3. Therefore, the proposed change will make Surveillance Requirement 4.7.1.5 consistent with Surveillance Requirement 4.3.2.3. Inherent'with this change is the elimination of the requirement for stroke time only testing. This is acceptable since the "stretch" power accident analysis only assumes a total time to full closure of 6.75 seconds. The stroke time would be indirectly verified with the proposed change. This testing provides adequate assurance that the assumptions in the MSLB accident analysis would be maintained.

The proposed change also revises the wording used in Specifications 4.7.1.5 and 4.7.1.6 to eliminate duplication. The type of test (full-stroke and part-stroke) and the frequencies and conditions currently delineated in Surveillance Requirement 4.7.1.5 and 4.7.1.6 conform with the testing requirements of Surveillance Requirement 4.0.5. By referencing Surveillance Requirement 4.0.5 in the MSIV and MFIV surveillance requirements sections, the inservice testing required by the ASME Boiler and Pressure Vessel Code Article IWV-3410 and applicable. addenda is adequately defined within the Technical Specifications. Plant test procedures address the exact plant conditions (reactor power and average coolant temperature) required during testing to assure the test adequately reflects as-designed conditions without significantly impacting plant operations. This proposed change does not result in a reduction nor an increase in the surveillance testing of the MSIVs or the MFIVs and therefore may be considered simply as an administrative change.

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ATTACHt1ENT 3 DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATIONS The standards used to arrive at a determination that a request for amendment involves no significant hazards considerations are included in the Commission's regulation, 10 CFR 50.92, which states that no significant hazards considerations are involved if the operation of the facility in accordance with the proposed, amendment would not (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety. Each standard is discussed as follows:

(1) Operation of the facility in accordance with the proposed amendment would not involve a significant increase in the probability or consequences of an accident previously evaluated.

Since the St Lucie Unit 2 "stretch" power accident analysis assumed a 6.75 second MSIV closure time and since the MSIV closure time does not affect the probability of an accident previously evaluated, the proposed closure time revision would not increase the probability or consequences of an accident previously evaluated. The surveillance test types and frequencies which are required only to limit the consequences of an accident, are essentially only reworded, therefore the probability or consequences of an accident previously evaluated is not affected.

(2) Operation of the facility in accordance with the proposed amendment would not create the possibility of a new or different kind of accident from any accident previously evaluated.

With respect to the MSIV cl'osure time limit, the creation of the possibility of a new or different kind of accident from any accident previously evaluated was considered as part of the "stretch" power safety analysis. The requirements on surveillance test types and frequencies remain unchanged based on the proposed editorial changes. The mode of operation of the MSIVs or MFIVs is not affected.

(3) Operation of the facility in accordance with the proposed amendment would not involve a significant reduction in a margin of safety.

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DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATIONS (continued)

The "stretch" power safety analysis assumes the MSIV closure in 6.75 seconds; therefore this proposed change does not alter the margin of safety with respect to limiting containment peak pressures or positive reactivity effects due to reactor coolant system cooldown during a postulated main steam line break accident. The requirements associated with the ASME Boiler and Pressure Vessel Code Article IWV-3410 and applicable addenda are maintained with the proposed wording revisions to Specifications 4.7.1.5 and 4.7.1.6, therefore the margin of safety is not changed.

Based on the above, the proposed amendment does not (1) involve a significant increase in the probability or consequences of an accident previously evaluated, (2) create the probability of a new or different kind of accident from any accident previously evaluated, or (3) involve a significant reduction in a margin of safety. Therefore the proposed license amendment does not involve any significant hazards considerations.

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