TXX-4618, Forwards Justification for Request for Exemption from 10CFR50,App J Requirements Re Containment Airlock Leakage Testing,Per NRC Withdrawal of Acceptance of Request to Relax Testing in Sser 12 (NUREG-0797).Fee Paid

Forwards Justification for Request for Exemption from 10CFR50,App J Requirements Re Containment Airlock Leakage Testing,Per NRC Withdrawal of Acceptance of Request to Relax Testing in Sser 12 (NUREG-0797).Fee Paid

ML20137M074
Person / Time
Site:	Comanche Peak
Issue date:	01/20/1986
From:	Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	Noonan V NRC - COMANCHE PEAK PROJECT (TECHNICAL REVIEW TEAM)
References
TXX-4618, NUDOCS 8601280179
Download: ML20137M074 (4)

Text

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Log # TXX-4618 TEXAS UTILITIES GENERATING COMPANYFile # 10010

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- Director of Nuclear Reactor Regulation Attention: Mr. Vince S. Noonan, Director Comanche Peak Project Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C. 20555

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION DOCKET NOS. 50-445 AND 50-446 REQUEST FOR EXEMPTION TO 10CFR50 APPENDIX J

Dear Mr. Noonan:

In Supplement 12 to NUREG-0797, the CPSES Safety Evaluation Report, the NRC Staff withdrew its acceptance of the CPSES request to relax the containment airlock leakage testing (10 CFR 50 Appendix J, Section III.D.2(b)(fi))

because the regulatory procedures mandated for the issuance of an exemption to the regulations (10 CFR 50.12) had not been fulfilled.

Based on guidance provided by the Staff and pursuant to 10 CFR 50.12(a),

attached is the CPSES justification for this exemption request.

Enclosed, in accordance with the requirements of 10CFR170.12(c), is a check in the amount of $150.00.

Should you have any questions in this matter, please contact this office.

Very truly yours, W. G. Counsil BSD/grr Attachment Enclosure pb,/V KIMW A UlVEN10N UV TEXAN ffTILITERN REECTNIC COMPANY 8601280179 860120 PDR ADOCK 05000445 E PDR

RE0 VEST FOR EXEMPTION TO 10CFR50 APPENDIX J Applicant requests a permanent exemption from the provisions of 10 CFR Part 50 Appendix J Paragraph III.D.2(b)(ii).

The requested exemption is authorized by 10CFR50.12, and there are no laws or regulations which would prevent the granting of the exemption.

The exemption will not present an undue risk to the public health and safety, is consistent with the common defense and security, and is in the public interest.

PUBLIC HEALTH AND SAFETY JUSTIFICATION Paragraph III.D.2(b) of Appendix J to 10 CFR 50 details three explicit air lock testing requirements which are further required to be included in the Technical Specifications. With one exception, Technical Specification 4.6.1.3 items a., b.1 and b.2 correspond to and comply with those Appendix J requirements.

Technical Specification 4.6.1.3.b.1 requires that containment air locks be demonstrated operable during periods when containment integrity is required by conducting a leak test at least every 6 months. The test requires pressurizing the interior of the air lock to Pa (the calculated peak containment internal pressure under design basis accident conditions, 48.1 psig for CPSES) and verifying that the leakage rate is within its limit. This is in compliance with Appendix J requirement III.D.2(b)(i).

Appendix-J paragraph III.D.2(b)(iii) requires that air locks be tested within 3 days after being opened (or at least once every 3 days for openings more frequent than every 3 days). For plants with testable seals, this requirement may be satisfied by testing the air lock seals at no less than Pa . Technical Specification 4.6.1.3.a corresponds to and complies with this portion of Appendix J.

The portion of Appendix J from which Ne seek an exemption is paragraph III.D.2(b)(ii). That provision requires that " air locks opened during periods when containment integrity is not required by the plant's Technical Specification shall be tested at the end of such periods at not less than Pa ." In lieu of this requirement, TUGCo requests that the Staff approve the existing Technical Specification 4.6.1.3.b.2 which requires that an overall air lock leakage test be conducted at Pa prior to establishing containment integrity if maintenance has been perfortred on the air lock that could affect the air lock sealing capability.

There are two air lock designs at CPSES. The personnel airlock is a 10 f t, diameter electro-hydraulically operated double door assembly. The emergency airlock is a 5 ft. 9 in.. diameter manually operated double door assembly. The existing emergency airlock' doors are so designed that full pressure test at Pa of an entire air lock can only be performed after strong backs (structural bracing) have been installed on the inner (containment) door. This is due to the fact that the pressure exerted on the inner door during the test-is in a direction opposite to that of force experienced during a postulated accident and the locking mechanisms

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are not designed to eithstand such reverse forces associated eith a

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pressure of Pa . Performing the test, with attendant' installation and removal of strong backs, is a cumbersome process requiring approximately.

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, during which access through the air lock is prohibited. The CPSES containments are designed.to permit frequent access in order to perform required surveillance and maintenance activities.

During periods when containment integrity is required, the periodic 6-month and 3-day test requirements of Appendix J are sufficient to assure that the air locks will satisfy the leak rate requirements. These same tests provide assurance that the air locks will meet the leak rate requirements following containment opening when containment integrity is.

not required, provided no maintenance has been performed which could affect air lock sealing capability. ,

Furthermore, this exemption is consistent with current regulatory practice and policy and is included as a part of the Standard Technical Specifications.

An exemption from paragraph III.D.2(b)(ii) of Appendix J, 10CFR50 is requested since this present Technical Specification provides equivalent protection to the requirement itself and does not endanger life or property.

PUBLIC INTEREST If strict compliance with the subject provision of Appendix J were

mandated, either a cumbersome and unwarranted test must be performed or a major design change would be required to permit the inner door of the emergency and personnel air locks to be tested in a less cumbersome manner. The remaining Appendix J test requirements for containment air lock testing in conjuction with the current Technical Specification post-maintenance test requirement achieve substantial compliance with the intent of the Appendix J requirements, th'us providing reasonable assurance that leak rate requirements will be satisfied.

An air lock design change could cause a significant delay in commercia'l operation of CPSES. The current design of the air lock employs industry accepted design standards; therefore design changes to achieve literal compliance with Appendix J would involve a lengthy prototype design and qualification process. Any changes to the current schedule which would delay the commercial operation of CPSES would cause the cost to increase at'the rate of more than $20 million per month (per unit). Under standard ratemaking practices, these costs would eventually have to be borne by ratepayers of the TUGCo companies.

In addition, if full compliance with the Appendix J testing requirement is undertaken using the current design, then periodically over the remaining life of the plant, a cumbersome and lengthy test must be

undertaken on one or both containment air locks. The additional plant shutdown time required to conduct these tests, over the life of the 1

plant, is substantial (since Appendix J requires the test be performed at the end of each period during which the air lock has been opened and the 2-

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plant must remain shutdown while performing this test). These tests could extend the duration of the outages by half a day or more several times a year. This would have significant financial impact on.the TUGCo companies and ultimately on the ratepayers as described above.

Either. implementation of a full compliance test requirement which results in increased outage time over the life of the plant, or implementation of '

a major design change which results in a delay in commercial operation, have a substantial financial impact on the.TUGCo companies and its customers and is not warranted inasmuch as, shown.above, the public j health and safety are adequately protected. i POIENTIAL ENVIRONMENTAL IMPACT The only incremental environmental impact which could be associated with this exemption request is related to a potential increased probability of containment leakage during an accident. Other areas of environmental

, impact (such as radiological and non-radiological effluents and other j non-radiological consequences or impacts) are not affected by the j requested exemption, t

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8ecause of existing Technical Specification surveillance requirements, the requested exemption involves a de facto requirement for an air lock i'

seal test in lieu of the Appendix J Paragraph III.D.2(b)(ii) test.

Paragraph II.D.2(b)(iii) already allows an air lock seal test in lieu of a similar required air lock test at a pressure of not less than Pa, thus i

recognizing the implicit equivalence of these tests under similar circumstances. Thus, it can be concluded that there ,'s reasonable assurance that no undue air lock leakage will be causeit by the exemption i and that there will be no significant increase in the probability or extent of air lock leakage (i.e., in excess of the design value for' post '

accident containment leakage). Therefore, there is no significant increase in the probability of higher' post accident doses relatedEto the

e:4emption and therefore no significant increase in environmental impact

! beyond that experienced without the exemption.

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