ML20151Y148

Exemption Granting Licensee 880219 Proposed Partial Exemption from 10CFR50,App J,Paragraph III.A.3 to Allow Use of Mass Point Method for Leak Rate Calculations W/Condition of 24 H Min Test Duration Until App Modified

ML20151Y148
Person / Time
Site:	Oyster Creek
Issue date:	04/18/1988
From:	Varga S Office of Nuclear Reactor Regulation
To:
References
NUDOCS 8805040362
Download: ML20151Y148 (5)

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%)'f' 7590-01 UNITED STATES OF AMERICA NUCLEAR RECULATORY COMMISSION In the Matter of q GPU NUCLEAR CORPORATION AND 1 Docket No. 50-219 JERSEY CENTRAL POWER AND LIGHT COMPANY l (OysterCreekNuclearGenerating i Station)

EXEMPTION I.

The CPU Nuclear Corporation and Jersey Central Power A Light Company (the licensee) are the holders of Provisional Operating License No. DPR-16, which authorizes operation of the Oyster Creek Nuclear Generating Station, (the facility) at steady state reactor core power levels not in excess of 1930 megawatts thennal. The license provides, among other things, that Oyster Creek Nuclear Generating Station is subject to all rules, regulations, and

, Orders of the Commission now or hereafter in effect.

The plant is boiling water reactor (BWR) located at the licensee's site in Ocean County, New Jersey.

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The Code of Federal Regulations, 10 CFR 50.54(o), specifies that primary reactor containments for water-cooled power reactors shall comply with Appendix J, "Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors." Paragraph III.A.3 of Appendix J incorporates by reference

the American National Standard ANSI N45.4-1972, "Leakage Wate Testing of (

Containment Structures for Nuclear Peactors." This standard requires *. hat 1

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containment leakage calculations for Containment Integrated Leakage Rate Tests l (CILRTs) be performed using either the point-to-point method or total time -

method.

A more recent standard, ANSI /ANS 56.8-1981, "Containment System Leakage Testing Requiremer ts," which was intended to replace ANSI N45.4-1972, specifies the use of the ness point niethod to the exclusion of the two older nethods.

A proposed revision to Appendix J, which has been published for public concent (53 FR 5985, February P.9.1988) would parmit the use of the mass point niethod provided it is used with a test duration of at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Pending approval of the revision to Appendix J, ifcensees who wish to use the mass point technique must submit an application for partial exemption from the requirement that Appendix J test calculations for CILRTs will conform with ANSI N45.4-1972.

III.

By letter dated February 19, 1988, the licensee requested a partial exen:ption from 10 CFR Part 50, Appendix J. Paragraph III.A.3, which requires that all CILRTs be performed in accordance with ANSI N45.4-1972, "Leakage Rate Testing of Containment Structures for Nuclear Reactors." ANSI N45.4-1972 requires that leakage calculations be performed using either the total time method or the point-to-point method. The licensee has stated in support of the application for exemption from Appendix J that the mass point niethod is a more accurate nrethod of calculating containn:ent leakage.

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2 It has been recognized by the professional constnity that the mass point methcd is superior to the two other methods, point-to-point and total tine, which are referenced in ANSI N45.4-1972 and endorsed by the present regulations.

The mass point nethod calculates the air mass at each point in tin;e, and plots it against time. A linear regression line is plotted through the mass-time points using a least square fit. The slope of this line is the leakage rate.

In addition to the nethod of calculation, consideration of the length of the test should also be included in the overall program. In accordance with Section 7.6 of ANSI N45.4-1972, a test duration less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is only allowed if approved by the NRC, and the only currently approved methodology for such a test is contained in Bechtel Topical Report BN-TOP-1, Revision 1, "Testing Criteria for Integrated Leakage Rate Testing of Primary Containnent Structures for Nuclear Power Plants," dated November 1, 1972. This approach only allows use of the total tin:e method. Therefore, the staff will condition the exenption to require a minin:um test duration of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> when the mass point nethod is used.

The licensee's letter also submitted infomation to identify the special circumstances for granting this exenption for Oyster Creek Nuclear Generating Station pursuant to 10 CFR 50.12. The purpose of Appendix J to 10 CFR Part 50 is to assure that containment leak-tight integrity can be verified periodically throughout the service lifetin.e so as to maintain containntent leakage rate within the limit specified in the plant technical specifications. The underlying purpose of the rule specifying particular nethods for calculating leakage rates l

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is to assure that accurate and conservative methods are used to assess the 1

results of containnent leakage rate tests. As set forth above, the mass point 1

n.ethod has been a widely used method providing accurate results and the staff has determined that this nethod of calculating leakage rate satisfies the purpose of the rule.

Based on the above discussion, the licensee's proposed partial exemption from paragraph III.A.3 of Appendix J, to allow use of the mass point method as requested in the submittal dated February 10, 1988, is acceptable with the condition of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> minimum test duration, until such provision of .\ppendix J is modified. The exemption applies only to the method of calculating leakage rate by use of the nass point method and not to any other aspects of the tests.

IV.

Accordingly, the Concission has determined that, pursuant to 10 CFR Part 50.1?, this exemption is authorized by law, will not present an undue risk to the public health and safety, and is consistent with the comon defense and j security. The Comission has further detemined that special circumstances, as set forth in 10 CFR 50.12(a)(?)(ii), are present justifying the exemption, nan,ely that the application of the regulation in the particular circumstances l is not necessary to achieve the underlying purpose of the rule. Accordingly, l the Comission hereby grants an exemption as described in Section III above from Paragraph III.A.3 of Appendix J to the extent that the mass point niethod i

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may be used for containment leakage rate calculations, provided it is used with a minimum test duration of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The exemption is granted until such provision of Appendix J is modified. The exemption applies only to the method of calculating leakage rate by use of the mass point n.ethod and not any other aspects of the tests.

Pursuant to 10 CFR 51.32, the Commission has determined that the granting of this exemption will have no significant inipact on the environment (53 FR.12617 April 15, 1988).  ;

l This exemption is effective upon issuance. l l

F0f THE NUCLfAR GULATORY COPFISSION p [ r A t d d.)\ l

- ven . rga, Dire r Division of Reactor P oj cts-I/II -

Office of Nuclear Reac r Regulation j l

Dated at Rockville, Maryland this April 18,1988

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