ML18054A937

Requests Exemption from 10CFR50,App J,Paragraph III.D.2(b)(ii) for Reduced Pressure Testing of Containment Air Locks.Justification for Exemption Encl

ML18054A937
Person / Time
Site:	Palisades
Issue date:	08/25/1989
From:	Berry K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
TAC-74369, NUDOCS 8908300002
Download: ML18054A937 (10)

Text

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consumers

• Power Kenneth W Berry Director PllWERINli Nuclear Licensing llllUllliAN'S PIUlliRESS General Offices: 1945 West Parnall Road, Jackson, Ml 49201 * (517) 788-1636 August 25, 1989 Nuclear Regulatory *commission Document Control Desk Washington; DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -

EXEMPTION REQUEST FROM 10CFR50 APPENDIX J PARAGRAPH III.D.2(Q)(ii)

FOR REDUCED-PRESSURE TESTING OF CONTAINMENT AIR LOCK (TAC NO. 74369)

By letter dated June 1, 1989, the NRC issued Amendment 126 to the Palisades operating license. This amendment incorporated a reduced-pressure local leak rate test of the containment air lock door seals into the Technical Specifications for periods when containment integrity is required. The NRC Safety Evaluation for this amendment identified an issue dealing with the requirements of 10CFR50, Appendix J Paragraph III.D.2(b)(ii) which remained to be resolved. Specifically, this paragraph requires a full air lock pressure.test at the end of periods when containment integrity is not required.

To resolve this issue, Consumers Power Company requests an exemption, pursuant to l0CFR50.12, from the requirement of 10CFR50, Appendix J, Paragraph III .D. 2 (b) (ii) wh;Lqh- -requires- the containment,.air -locks- to ..be tested .at not less than the calculated design basis accident peak containment*internal pressure_(Pa) at the end of periods when containment integrity is not required. In lieu of the full air lock pressure test at Pa, a reduced-pressure t'est_ at not less tha,n 10 psig would be performed, as is_ done for periods when containment integrity is required. Justification for the exemption is enclosed as Attachment 1.

Kenneth W Berry Director, Nuclear Licensing CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades Attachments.

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• ATTACHMENT 1 Consumers Power Company Palisades Plant Docket 50-255 EXEMPTION REQUEST FOR REDUCED-PRESSURE TESTING OF CONTAINMENT AIR LOCK AT THE END OF PERIODS WH~N CONTAINMENT INTEGRITY IS NOT REQUIRED August 25. ;* 1989 2 Pages OC0889-0176-NL04

• EXEMPTION REQUEST FOR REDUCED-PRESSURE TESTING OF CONTAINMENT AIR LOCK AT THE END OF PERIODS WHEN CONTAINMENT INTEGRITY IS NOT REQUIRED Paragraph III.D.2(b)(ii) of Appendix J to lOCFRSO requires that "air locks opened during periods when containment integrity is not required by the Plant Technical Specifications shall be tested at the end of such periods at not less than. Pa." Paragraph III.D.2(b)(iii) of Appendix J to 10CFR50 requires that "air locks opened during periods when containment integrity is required by the Plant Technical Specifications shall be tested within three days after

• being opened. * ** (F)or air lock doors having testable seals, testing the seals fulfills the three-day test requirement. In the event that the testing cannot be at Pa, the test pressure shall be as stated in.the technical specification."

Palisades Plant requests an exemption from lOCFRSO*, Appendix J, Paragraph III.D.2(b)(ii) *that would ~llow a reduced-pressure between the seals test to be performed in lieu of a full air lock pressure test, at the calculated design basis accident peak containment internal pressure (Pa), at the end of periods when containment integrity is not required *by technical specification, provided.no mainte~ance 'or modification that could affect sealing capability

• has been performed on an air lock.* If maintenance or modification that affects sealing capability is performed during the period,* full air lock pressure testing is conducted at the end of the period.

Attachment 2 is a letter dated August 29, 1984 to the NRC. from Consumers Power Company which provides a conservative interpretation of 10CFR50 Appendix J for containnient air lock testing under which Palisades has been conducting air lock testing. The NRC Safety Evaluation for Amendment 126 to the Palisa_des Operating License, dated June 1, 1989, acknowledged .this practice and requested Consumers Power -Company to submit an exemption *request*-

At Palisades, special circumstances_exist in that application of.the regulation in the particular circumst~nce-s is not necessary. to achieve the underlying purpose of the rule.. Testing the air lock per the attached letter

• will achieve the µnderling. purpose of Appendix J. That is, the. integrity of :

the air locks will be proven by the same methods that the integrity of the air lock is proven while the plant requires containment integrity. This method allows reduced-pressure testing provided a test of the entire air lock assembly is performed at least once every six months at Pa.

Since the integrity of the air lock is proven by a redu~ed-pres~ure between_

the seals test during periods when containment integrity is required, there is no technical reason why the integrity of the air lock*cannot be proven by the same methods during periods when containment integrity is not required. This is deemed an appropriate -level of testing since the probability of damaging the air lock such that a full pressure test would detect leakage, is the approximately the same whether the plant is in cold shutdown or power operation.

OC0889-0176-NL04

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-In addition, strict c-ompliance with the regulation results in undue hardship and other costs that are significantly in excess of those contemplated when the regulation was adopted. The test at Pa requires approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to conduct (includes setup, pressurization, decay.and dismantling of test equipment) whereas reduced-pressure testing may be performed in approximately two to four hours. The additional time to perform the test at Pa is deemed to be an undue hardship and increased cost, given the fact that reduced-pressure testing verifies the capability of the seals.

OC0889-0176-NL04

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ATTACHMENT 2 Consumers Power Company Palisades Plant Docket 50-255 10CFR50 APPENDIX J INTERPRETATION LETTER DATED AUGUST 29, 1984 August 25, 1989 5 Pages L

OC0889-0176-NL04

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consumers

~ Power company*

Generel Offices: 1946 West Parnell Aoad, Jackson, Ml 49201 * (5171 788-0550 August 29, 1984 Director, Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT 10CFR50 APPENDIX J INTERPRETATION CONTAINMENT AIR LOCK TESTING This interpretation of lOCFRSO Appendix J, III, D, 2. (b) (i), (ii) *and (iii) is.*

provided in response to concerns raised by the Palisades Plant staff regarding testing of the entire personnel airlock at internal pressures of not less than the peak calculated acciqent pressure (Pa). The Pa test requires approximate-ly 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to conduct (includes set-up, pressurization, decay and dismantling of test equipment) whereas a between-the-seals test may be performed in approximately 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

In the past, the*Palisades Plant staff has conservatively interpreted the requirements of paragraph III, D, 2.(b)(ii) that a test of the entire air lock assembly before returning to power operations following a cold shutdown is required.*Since the Palisades Plant Technical Specifications do not require containment integrity to be-maintained during cold shutdown, this same require-

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• ments implies that* a Pa* test must be performed any time a forced outage places the plant in a cold shutdown mode regardless of the fact ~hat - 1) containment integrity was indeed maintained throughout the duration of the outage; and, 2) a_Pa_test of .the air lock assembly is performed~very six months.

Appendix J, III, D, 2.(b)(iii) permits a between-the-seals test for air locks having te"&table seals. This test, in accordance with III, D, 2.(b)(iii) is performed a~'..the..Falisades Plant during periods of power operation (or any period where containment integrity is required) following an entry into the containment. NRC staff guidelines (reference the attachment to this letter which was supplied by letter to the Big Rock Po.int. Docket No 5.0-155, dated August 4, 1980) provide further guidance for an "intermediate test11 of the door seals whenever containment integrity is required. Consumers Power Company, having reviewed the attached Staff position interprets the inter-mediate test as also applicable during periods where containment integrity is

~ot required provided the following requirements have been satisfied:

OC0884-0015-NL02

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Dire~tor, NRR 2 Palisades Plant .

CONTAINMENT AIR LOCK TESTING August. 29, 1984

1. A test of the entire air lock assembly is performed once every six months at Pa.

2. A*reduced-pressure test is performed within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of every first-of-a series of openings during the interim, between the six month tests.

3. Containment integrity has been maintained since the last Pa test.

We believe this interpretation is consistent with NRC staff. positions and objectives of the air lock-testing requirements. Discussions with the Resident Inspector - Region III and a representative of your staff regarding this information occurred onAugust 27 thru 29, 1984. The Palisades Plant Review Committee has also reviewed this interpretation and has found it does not constitute on*unreviewed safety question. Procedures have been revised

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accordingly.

Thomas C Bordine (Signed)

Thomas C Bordine Staff Licensing Engineer CC Administrator, Region III, Ul USNRC NRC Resident Inspector - Palisades Ln Attachment OC0884-0015-NL02

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ATTACHMENT 0 Consumers Power Company Ln Palisades Plant - Docket 50-255 lOCFRSO APPENDIX J INTERPRETATION

.CONTAINMENT AIR LOCK TESTING

- 2 Pages OC0884-0015B-NL02

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• APPENDIX A CONTAINMENT AIRLOCKS

• Appendix J to lOCFllSO require* that reactor containment airlock.a be leak-tested at the peak calculat*d accidesit pressure (Pa) at aix-month intervala.

Further, ahould the airlock.a be opened during such interval*, the airlock* vili be leak-teated after each opening. Appendix J call* out these apecific require-meDt* for airlocks becauae they present potentially large leakage path* which are subject to human error to ** larger degree than othe~ potentiai leakage paths.

The *taff'a.interpretatioll of the objective* of the airlock-leak-testing requirement* are:

1. That the six-month test will provide an 1ntegrated leakage rate for the entire airlock aa*embly including electrical and mechani-cal penetrationa, the airlocks cyl1nder; hinge aasembliea, welded tn connection*, and o~her potential leakage patha.

2. That the "after-each-open1ng" test would provide a means of ensur-ing that the door *e.al* bad not been dam.aged or aeated improperly dur1ng airlock uae.

For thoae operat1ng facilitie* t~t ver*1 deaigned and constructed prior to the issuance of Appendix J, con*ideration baa been given to the alternatives to r...... the specific testing requirementm which will me£t the provisions of Appendix J.

tn Listed below are a number of guidelines which may be uaeful vhen cons.idering or Lil revising current airlock~leak*testillg*progr~.

I"'> 1.

• Ai:*siz-mc>nth interval* _the_ 91ltire_a~rlock assembly *hall- be leak-

.- testecf at _the. 'puk __ pru.Ure, Pa.. U the test presaur* vill lift.

the inner airlock door off it* seat, a *trongback or ~ther aecbani-cal device should be uaed ao that aeaningful test results can be obtailled at Pa.

2. Should the airlock be opened during the interval between.the *iz-month teat*., the airlock door **al* ab&ll be teated within 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />s- of every first of a *eriea of openings. Thia relaxation in the "aft"er-each-opening"*teat requirement of Appendiz J recognizes that a aignif icant amount of time i* required to conduct these intermediate teat* in relation to the frequency of.use of-the air-lock. These test* would be conducted vheilever containment integ-rity i* required.

3. For thoae plant* which require the uae of a 9trongback or clamps to leak-teat the door aeal* at a preasure, Pa, a lover pressure (e.g., aanufacturer'* recommended pressure, which would not require the uae of auch clamping device*) ahould be uaed to con-duct the intermediate teata. The reaulta *of leakage teat* at the

• reduced pressure must be conaervatively extrapolated to the

• leakage at the accident pressure, Pa, to determine accept-ability. (The extrapolation to be utilized must be submittect to the Hlt.C.)

In lieu of the intermediate testa, an acceptable alternative vuuld be the uae of a continuous monitoring syatem to achieve the objective of the "after-each-opening" test requirement. As in the case of the reduced-pre1aure inter-mediate test, it must be demonstrated that the continuoua monitoring aystem is

.uff iciently aensitive to detect unacceptable leakage rate* and that the accept-able leakage-rate limits will be baaed upon a conservative extrapolation to the limiting leakage rate experienced under accident condition* (e.g., at a presaure of Pa).

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