ML20128N161
| ML20128N161 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 02/16/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20128N166 | List: |
| References | |
| NUDOCS 9302230103 | |
| Download: ML20128N161 (6) | |
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UNITED 5TATES NUCLEAR REGULATORY COMMISSION p,
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR prl.lATION RELATED TO THE RE0L'E.ST FROM EXEMPTION FOR ASME SECTION XI INTERVAi_ DATES INSERVICE TESTING PROGRAMS FOR PUMPS AND VALVES VIRGINIA ELECTRIC AND l'0WER COMPAN]
SURRY POWER STATION UNIT 1 & 2 DOCKET NUMBERS 50-280 AND 50-281 1.0 Introduction The Code of Federal Regulations, 10 CFR 50.55a, requires that inservice testing (IST) of certain ASME Code Class 1, 2, and 3 pumps and valves be performed in accordance with Sectic.1 XI of the ASME Boiler and Pressure Vessel Code and applicable addenda.
The Code of Federal Regulations,10 CFR 50.12 states that:
The Commission may, upon application by any interested person or upon its own initiative, grant exemptions from the requirements of the regulations of this part, which (1) Are authorized by law, will not present an undue risk to the public health and safety, and are consistent with the common defense and security.
(2) Meet the requirement that special circumstances are present.
Special circumstances are present whenever-(ii)
Application of the regulatior, in the particular circumstances would not serve the underlying pt. pose of the rule or is not necessary to achieve the underlying purpose of the rule.
This Safety Evaluation (SE) concerns an exemntion request and supporting information that was submitted by Virginia Electric and Power Company (the licensee) in a letter dated November 10, 1992, for the Surry Unit 1 IST Program second interval end date (or third interval start date). The licensee states that the Surry 1 second 10-year test interval ends on Octcber 14, 1993 based on extended outages at Surry Units 1 and 2.
However, the NRC staff considers the end date to be December 22, 1992, the original second 10-year
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interval lend date, based on the commercial operation date of December 22, 1972.
The Surry Unit I second~ interval IST Program-was developed to be consistent-with the ASME Boiler and Pressure Vessel. Code Section XI, 1980~
Edition, Winter 1980 Addenda.
The NRC staff's findings with respect to granting or not granting the exemption are contained in this SE.
2.0 Exemption Reauest The licensee has requested an exemption from the requirement of.50.55a (f)(4)(ii) [formerly (g)(4)(ii)] which requires that:
Inservice tests to verify operational readiness of pumps and valv.es,.
whose function is required for safety, conducted during successive'120<
month intervals must comply with the requirements of the-latest edition '
of the Code incorporated by reference in parag6ph (b) of this section-12 months prior to the start of the 120-month interval, subject _ to the limitations and modifications listed in paragraph (b) of this section.
That is, the licensee _ requests to extend the the_second ten-year test interval from October 14, 1,93, to May 10, 1994. Consequently, the licensee will not' be using the more recent version of the Code during this period'of time.
2.1 Licensee's Basis for the Exemotion Reouest The. licensee states:
Due to ext nded maintenance outages, both Surry Units 1(and 2-have extended their inservice testing intervals in accordance with the-provisions of the' Code.
However, the interval! start dates are different by seven months.
Pursuant to 10 CFR 50.12,cwe are requesting an exemption from the requirements of 110 CFR 50.55a-(g)(4)(ii) to postpone-the Unit I third interval _ inservice. testing start date until_May 10, 1994, to coincide with the Unit 2 third interval-start--date, Specifically,10 CFR 50.12 (a)(2)(ii) states in;part, that the.NRC.will.
consider granting an exemption whenever application of the. regulation isi 4
not necessary to achieve tha Jnderlying purpose'of the rule. _ Th( Curry Unit I second interval inservice testing program will continue to oe _
implemented in accordance with the existing approved program antil the-start of the third interval. Therefore, the operational readiness ~of-~
the pumps and valves, whose function'is required.for safety, will' continue to be assured until-the third interval commences on MayL10,.-
1994. Continued: implementation of th: existing second: interval program meets the underlying purpose 'of the regulation. ~
The following admin.istrative: benefits result from th.e Unit _1 third interval start date being postponed to coincide with-the corresponding Unit 2 third interval start date. The Inservice Testing Programs for-Unit I and ? would be on and remain on_the same interval and-require compliance with the same edition of-the Code and addenda. Therefore.
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the testing requiremer,ts would be consistent..This will simplify our-program preparation l review and preparation-for the third interval,:as well as the associated program review by:the NRC.
likewise,= any relief _.
requests submitted during the third interval-would be similarly simplified.. A common start date.will also reduce the program administration burden by permitting only a single submittal tolbe made for both' units.
2.2 Proposed Alternative The licensee stated that:
The Surry Unit 1 second interval inservice testing program will continue-N to be implemented in accordance with the existing approved program until I
the start-of the third-interval..
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2.3 Evalo q
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The licensee icates that both units will be subject to the same.IST:
requirements s regards Code edition and schedule.for future periodic upates' and will, thus, be on concurrent inservice testing intervals.
The licensee ^
proposes to use the extended interval,!rather than the commercial' operat.iun' date, of Unit 2 for l establishing the 120-month interval-for both' units beginning May 1994. 'The. staff has htermined that for facilities which include two similar units, it is advantageous to implement.an_IST program
-consistent between units by using the.same Code edition:for-developing the,
program and for scheduling ten-year updates.
Section 50.55a(4)(f)(iv) allows-the use of later editions of the Code provided the NRC hcs indicated approval
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in s 50.55a (b); and,.therefore, allows the licensee to update programs during-the 120-month intervals without revising the' interval dates.. The IST interval' need not be consistent with the -inservice inspection-interval and this approval does not address-' inservice inspection.
Section XI of the-ASME Boiler and-Pressure Vessel Code-section IWA 2420tstates that "[tlhe inspection intervals shall comply with the following, except as modifico by IWA-2400(c):
1st Inspection Interval - 10 years following initial. start of power unit commercial operation 2nd Inspection Interval - 10 years following the 1st inspection 1 interval 3rd Inspection Interval - 10 yea'rs following the 2nd inspection-interval 4th Inspection Interval - 10 years following the 3rd inspection interval" Surry Unit I commenced commercial operation on December-22, 1972.
Surry Unit.2 commenced commercial operation on May 1,1973.
IWA--2400(c) states that "[ejach inspection interval may.be decreased or--
extended (but not cumulatively) by as much as one year.. For power units that are out of service continuously for 6 months or more, the inspection: interval
- during which the outage occurred may be extended for a period equivalent to the outage."
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4 According to the licensee, "Due to extended maintenance outages, both Surry Units-1 and 2 have extended their inservice testing intervals in accordance
-with the provisions of the Code."
That is, the IST interval for Surry' Unit 1 has been extended from December 22, 1992, to October 14, 1993, in accordance with the provisions of IWA 2400(c). The licensee now proposes to further extend the 2nd-inspection interval end date-to May 10; 1994. The licensee is' seeking an exemption from 10 CFR 50.55a (f)(4)(11) because this extension is-not in accordance with the provisions of the_ Code.
10 CFR 50.55a (f)(4){ii) states:
Inservice tests to verify operational readiness of pumps and valves, whose function is required _for safety, conducted during. successive.120 -
month intervals must comply with the requirements of the latest edition of the Code incorporated by reference in. paragraph (b) of this. section 12 months prior to the start of the 120-month interval,. subject to the limitations and modifications listed in paragraph (b) of this section.
There is no explicit provision in the regulation for extending the 120-month-interval as is provided in IWA-2400(c) for power. units that.are out-of service continuously for 6 months or more.
However, paragraph (b): of 5 50.55a of the regulation has endorsed, by reference, editions of Section XI of the ASME_ Code that provide for extending the interval by as much.as one year.
To extend:an interval beyond the 120 months, and beyond the 12 months allowed by ASME-Section XI, an exemption is necessary for compliance. The staff views-the-allowance for an extension provided in the Code as a means-for licensees to complete inspections during refueling outages which may be-scheduled bcyond-the 120-month interval _ date. ~ While this allowance is more directly related to inservice inspections (ISI) than IST, it is acceptable, _though not imperative, to maintain the ISI and IST intervals coincident. Additionally, specific inspections may be extended under_the Code provision without revising the interval dates.
Nevertheless, str<ct adnerence to the 120-month interval is:not necessary to, achieve the underlying purpose of the rule.
That is, the ope' rational readiness of the pumps -and valves, whose function _is required for. safety, will' be adequately assured using the existing Code requirements entil the third interval commences on the later date, that is, May 10, 1994. Continued implementation of the existing second interval program meets the1nnderlying purpose of the regulction and therefore, "special circumstances" exist as -
defined in 10 CFR 50.12.
Additionally, the requirements of_the 1980 Edition, Winter 1980 Addenda.(the' licensee's current edition of Section XI forL IST), in comparsion to the requirements of the 1986 Edition -(the edition which the licensee would have-u:,ed based on the commercial operation date of Surry Unit 1) or the 1989 Edition (the edition the-licensee would-usc based on the extended date' of._
October 1993), are_not significantly different. -The IST requirements for..
safety and relief valves, including an expansion of the scope of valves to be tested, changed.in the 1986 Edition of Section XI. However, the testing frequency for safety andl relief valves is based on a five-year schedule forf
- Class 1 valves and a ten-year ' schedule for Class 2.and 3 valves.
Therefore,'
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evtending the date for updating to a later edition of the Code does not significantly impact implementation of the overall testing program. The remainder of the components will continue to be tested to requirements that have not changed or have been deleted by the later editions of the Code.
Recognizing that there will be administrative advantages and consequent resource savings for both the licensee and the NRC, by having the same IST program for both Surry Units 1 and 2 (i.t., by having concurrent IST.
intervals), the NRC is inclined to grant a one-time exemption from the requirement that the IST program be updated within 120-months.
Extending the IST program intarval for Surry Unit 1 from December 22, 1992, to May 10, 1994 (i.e., 17 months), on a one-time basis, to be concurrent with the Surry Unit i interval, is authorized by law, will not present an undue risk to the public health and safety, and is consistent with the common defense and security.
2.4 Conclusion The licensee is wereby granted a one-time exemption from the requirement of 50.55a(f)(4)(ii) [formerly (g)(4)(ii)] to update the IST program for Surry Unit I by the end of the current 120-month intet val (i.e., December 22, 1992).
The requireo IST program update shall occur on or'before May 10, 1994.
The 3rd interval IST program for Surry Unit I shall comply with the requirements of the latest edition of the Code incorporated by reference in paragraph (b) of 50.55a 12 months prior to the start of the 3rd inspection interval (i.e.,
referenced in 50.55a as of May 10, 1993), subject to the limitations and modifications listed in paragraph.(b) of 50.55a.
The end of the 3rd (and subsequent) inspection interval for Surry Unit I shall be adjusted consistent with the granting of this exemption request (a.g., May 10, 2004).
Principal Contributor:
David C. Fischer Date: February 16, 1993
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Memorandum Dated February 16, 1993 Distribution Docket File.
NRC & Local PDRs PDil-2 RF S. Varga G. l.alnas H. Berkow E. Tana B. Buckley D. Fischer 0GC ACRS (10)
M. Sinkule, Ril
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