ML20073M408

Exemption from Conducting Third Type a Test in 10 Yr Svc Period During Unit Shutdown for 10 Yr ISI

ML20073M408
Person / Time
Site:	San Onofre
Issue date:	05/07/1991
From:	Boger B Office of Nuclear Reactor Regulation
To:	SAN DIEGO GAS & ELECTRIC CO., SOUTHERN CALIFORNIA EDISON CO.
Shared Package
ML20073M412	List: ML20073M408
References
NUDOCS 9105150113
Download: ML20073M408 (5)

Text

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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of SOUTHERN CALIFORNIA EDISON COMPANY, SAN DIEGO GAS & ELECTRIC COMPANY, Docket Nos. 50-361 THE CITY OF ANAHEIM, CALIFORNIA, AND and 50-362 THE CITY OF RIVERSIDE, CALIFORNIA (San Onofre Nuclear Generaung Station, Unit Nos. 2 and 3)

EXEMPTION 1.

The Southern California Edison Company, San Diego Gas & Electric Company, The City of Anaheim, California, and The City of Riverside, California (the licensee) hold Facility Operating License Nos. NPF-10.and NPF-15, which authorize operation of the San Onofre Nuclear Generating Station, Unit Nos. 2 and3(thefacilities). The licenses provide, among other things, that the facilities are subject to all rules, regulations and orders of the Nuclear Regulatory Commission (the Commission) now or hereafter in effect. These facilities are pressurized water reactors located in San Df sgo County, i

California.

II.

GeneralDesigi. Criterion.(GDC)52ofAppendix-Ato10CFRPart50 requires that each reactor containment be designed so that periodic integrated :

leakage rate testing can be conducted to assure containment isolation integrity. Sectio:1 III.D.1(a) of Appendix _4 to 10 CFR Part 50 requires that.

the third Type A test in a 10-year service period shall be conducted when the unit is shut down for the 10-year unit inservice inspection (ISI).

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The Type A tests are conducted to measure the primary reactor containment integrated leakage rate.

They are also known as the containment integrated leak rate tests (ILRT). These tests are required by Appendix J to assure that l

the containment leakage following a large break loss-of-coolant accident is less than the maximum allowable leak rate assumed in the accident analysis.

In addition to the Type A tests, Appendix J requires Type B and Type C tests of leakage through containment penetrations and containment isolation valves to also assure containment integrity during an accident.

This requested exemption does not affect the requirements on (1) the Type B and Type C tests in Appendix J

J or (2) the maximum allowed containment leakage rate in Appendix J and the San Onofre Unit Nos. 2 and 3 Technical Specifications.

The containment is required to be operable when the unit is at reactor system conditions above cold shutdown and refueling.

The containment is not required for cold shutdown or refueling.

By letter dated April 8, 1991, the licensee requested an exemption from the Type A testing requirements in Section III.D.1(a) of Appendix J.

This is an exemption from conducting the third Type A test in a 10-year service period l

during the unit shutdown for the 10-year inservice inspection (ISI).

For example, the third Type A test for the first 10-year service-period for San Onofre 2 is scheduled for the San Onfore Unit 2 Cycle 6 refueling outage in August 1991. The licensee contends that, because the 10-year ISI has been extended beyond 1991, (Cycle 7 refueling outage) the inspection is not recessary for the Unit 2 Cycle 6 refueling outage and, therefore, must be 4

unceupled from the third Type A test in each 10-year service period which is required by Appendix J.

(A similar situation exists for Unit 3). To perform a fourth Type A test during the sate shutdown as the 10-year plant ISI

i (Cycle 7 refueling outage) would only sati:.fy the Technical Specification requirement to perform a Type A test c.uring the same shutdown for the 10-year plant ISI. Additionally, performing a fourth containment ILRT, for the sole purpose of being done during the same outage as the 10-year ISI, v)uld not necessarily enhance the purpose, or provide further assurance of containment

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integrity above that which has already been demonstrated.

1 The 10-year ISI is not related to the integrity of the containment pressure boundary. The purpose of the Appendix J test program is to ensure that leakage through the primary reactor containment does not exceed allowable leakage rate values. The purpose of the ISI program is to ensure that structural integrity of Class 1, 2, and 3 components is maintained in accordance with ASME Code requirements. Therefore, the proposed separation has no safety consequences because the requirements on containment integrity in Appendix J and the San Onofre Unit Nos. 2 and 3 Technical Specifications, and on structural integrity of Class 1, 2, and 3 components in the ASME Code 4

are not being changed by the proposed exemption.

i The staff has considered the Appendix J exemption request for uncoupling the third Type A test of each 10-year service period from the 10-year unit ISI and concludes it is justified on the grounds that the third Type A test within i

each 10-year service period and the 10-year ISI may be scheduled separately, and the safe operation of San Onofre Unit Nos. 2 and 3 does not require that the two tests be conducted in the same outage. The licensee is still required to conduct the 10-year ISI in accordance with Section XI of the ASME Code.

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i Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12, i

the exemptions are (1) authorized by law, (2) sill not present an undue risk to j

public health and safety, and are (3) consistent with the comon defense and i

se curity. The Commission further determines that spccial circumstances, as i

l provided in 10 CFR 50.12(a)(2)(ii), are present' justifying the exemption --

i namely, that application of the regulation in these particular circumstances is not necessary to achieve the underlying purpose of the rule in that the San Onofre Unit Nos. 2 and 3 containment will continue to provide a reliable and i-acceptable means of containment isolation integrity within the leakage-require-ments of Appendix J; and the San Onofre Unit Nos. 2 and 3 Technical Specifica-tions and the 10-year ISI will still be conducted in accordance with the ASME i

j Code.

j When Appendix J was adopted, the end of the 10-year service period and the 10-year inservice inspection outage were contemplated to be concurrent l

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milestones; however, these milestones are unrelated within the meaning of i

containment integrity because the-10-year ISI is not conducted to assure i

containment integrity. The Type A, B, and C tests of Appendix J: assure containment integrity. The rule did not anticipate' extended outages that-i would extend the.10-year ISI in accordance with the ASME Code. Performing the 10-year ISI early and concurrent with the third Type A test in a 10-year I

s'ervice, period _is not necessary to assure containment-isolation integrity and:

i would impose a hardship on the license'e with little or notincrease in the i

level of quality or safety at dan Onofre Unit Nos. 2 and--3. =

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Accordingly, pursuant to 10 CFR 50.12(a)(2)(ii), the Commission bereby i

grants an exemption from the requirements of Section III.D.I(o) of Appendix J 5

to 10 CFR Part 50 to the licensee for operation of the San Onfore Nuclear Generating Station Unit iios. 2 and 3, as described aoove.

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Pursuant to 10 CFR 51.32, the Commission has determined that the issuance 2

of this exemption will have no significant impact on the environment. This I

was noticed in the Federal Register (56 FR 20629, May 6,1991).

5 This exemption is effective upon issuance.

FOR THE NUCLEAR REGULATORY COMMISSION Original Signed By i

Bruce A. Boger, Director Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation Dated at Rockville, Maryland this 7thday of May 1991 L

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