U-600296, Requests Exemption from 10CFR50,App J Leak Testing Requirements for MSIVs & Containment Air Lock.Justification for Exemption & marked-up Proof & Review Tech Specs Encl

Requests Exemption from 10CFR50,App J Leak Testing Requirements for MSIVs & Containment Air Lock.Justification for Exemption & marked-up Proof & Review Tech Specs Encl

ML20138B101
Person / Time
Site:	Clinton
Issue date:	12/09/1985
From:	Hall D ILLINOIS POWER CO.
To:	Butler W Office of Nuclear Reactor Regulation
References
U-600296, NUDOCS 8512120208
Download: ML20138B101 (9)

Text

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. U- 600296 L30-85(12-09)-L 1A.120 ILLINDIS POWER COMPANY IP CLINTON POWER STATION. P.O. BOX 678. CLINTON, ILLINOIS 61727 December 9, 1985 Docket No. 50-461 Director of Nuclear Reactor Regulation Attention: Mr. W. R. Butler, Chief Licensing Branch No. 2 Division of Licensing U.S. Nuclear Regulatory Commission

Washington, D.C. 20555

Subject:

Clinton Power Station Request for Exemption from 10CFR50, Appendix J Leak Testing Requirements

Dear Mr. Butler:

In accordance with 10CFR50.12 of the Commission's i regulations, Illinois Power Company (IP) hereby requests that the

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'NRC grant specific exemptions to the leak test requirements of Appendix J to 10CFR50 for the licensed operating lifetime of the

Clinton Power Station. This relates to the following two specific elements of the Clinton Power Station (CPS) containment leak rate testing program

1. Main Steam Isolation Valves (MSIVs) 10CFR50, Appendix J, aaragraph III.C.3 requires that the measured MSIV leakage be included in the combined leak rate for the local leak rate tests. As discussed in Supplement #2 to the CPS Safety Evaluation Report

, (SSER f2), NUREG-0853, Section 6.2.6, IP has provided t

information describing the method proposed for use at CPS which includes leak testing the MSIVs at the peak calculated containment aressure for the design-basis accident but excludes tie measured leakage from the combined local leak rate. SSER #2, page 6-7, indicates i

i the Staff's acceptance of the CPS arogram. CPS

Technical Specification 3/4.6.1.2 3as been written to this position.

4 fa f2.

Containment Air Lock

! -5 E 10CFR50, Appendix J, paragraph III.D.2(b)(ii) requires

! $2 T! that " Air locks open during periods when containment i gi!!5 3 integrity is not required by the plant's Technical 2

!; s!; Specifications shall be tested at the end of such

~' periods at not less than Pa." In lieu of this Ihr 3 d'E~OE8 8E requirement, IP proposes an alternative test which is l 9 consistent with the assumptions and provisions of the l 0 i Standard Technical Specifications (NUREG-0123) and i

current regulatory practice and policy.

8512120200 851209 L 'f"f i

• I L -- -_ _ ___ _

U-600296 L30 85(12-09)-L 1A.120 Implementation of the III.D.2(b) (ii) requirement would impose significant hardship on CPS when the r.irlock has been used only for passage and when no maintenance has been performed that could affect the sealing capability.

Attached hereto is a more detailed discussion of each of these specific exemption requests along with the appropriate justifications for each. An affidavit in support of these requests is also attached.

Please contact F. A. Spangenberg of my staff if there are any questions regarding this request.

Sincerely yours, D. P. Hall Vice President TLR/kaf Attachment cc: B. L. Siegel, NRC Clinton Licensing Project Manager NRC Resident Office Regional Administrator, Region III, USNRC Illinois Department of Nuclear Safety

1 U-600296 L3 0 - 85(12-09 )-L 1A.120 AFFIDAVIT ILLINOIS POWER COMPANY  :

ss.

COUNTY OF DEWITT  :

D. P. Hall being first duly sworn, deposes and says:

That he is Vice President of Illinois Power Company, the Applicant herein: that he has reviewed the foregoing request, pursuant to Section 50.12 of the United States Nuclear Regulatory Commission's regulations, for certain specific exemptions to the requirements of Appendix J to 10CFR Part 50 together with the Justification For The Requested Exemptions and knows the contents thereof and that the statements and matters set forth therein are true and correct to the best of his knowledge, information and belief.

D. P. Hall - Vice President Subscribed and sworn to before me this day 9) of 1985.~

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O rO l \'

'llotary Public

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U-600296 L3 0 - 85 ( 12-09 )-L 1A.120 JUSTIFICATION FOR THE REQUESTED EXEMPTIONS TO 10CFR50 APPENDIX J NRC regulations provide for specific exemptions in 10CFR50.12(a). The Commission has provided additional guidance regarding ghis regulation in an order in the Shoreham 2 proceeding , as modified by Commission action on July 25, 1984 In accordance with 10CFR50.12(a) and the Commission's guidance regarding the issuance of exemptions, the Staff may grant exemptions under the following circumstances: (1) the activities to be conducted are authorized by law, (2) operation with the exemption does not endanger life or property because such would not involve undue risk to the health and safety of the public, (3) the common defense and security are not endangered, and (4) the exemption is in the public interest because, on balance, there is good cause for granting it and the public health and safety are adequately protected.

I. The Recuested Exemptions and the Activities Which Would Be Allowec, Thereunder Are Authorized by Law If the criteria established in 10CFR50.12(a) are satisfied, as they are in this case, and if no other prohibition of law exists to preclude the activities which would be authorized by the requested exemption, and there is no such prohibition, then the Commisgion is authorized by law to grant this exemption request II. The Requested Exemptions Will Not Endanger Life or Property A. Containment Air Lock Testing 10CFR50, Appendix J, Paragraph III.D.2(b) details three explicit air lock testing requirements. Proaosed CPS Technical Specification 4.6.1.3 items a and 3 correspond to, and comply with, those Appendix J requirements with one exception.

Appendix J Paragraph III.D.2(b)(ii) requires that " Air locks opened during aeriods when containment integrity is not required by the plant's Technical Specifications shall be tested at the end of such periods at not less than Pa." Whenever the plant is in OPERATIONAL CONDITIONS 4 or 5, PRIMARY CONYAINMENT INTEGRITY is not required. Therefore, if an air lock is opened during either of these conditions, paragraph III.D.2(b) (ii) requires that an overall air lock leakage test at not less than Pa be conducted prior to entry into OPERATIONAL CONDITION 3.

U- 600296 L30 - 85 (12-09 )-L 1A.120 This requirement is excessively restrictive since it requires a termination of containment entries while preparing to leave OPERATIONAL CONDITION 4 until the air lock that was opened and operated in OPERATIONAL CONDITION 4 or 5 is tested pursuant to paragraph III.D.2(b) (ii). PRIMARY CONTAINMENT entries during OPERATIONAL CONDITION 4 are important to ensure that surveillance requirements and minor maintenance activities are completed. The requirements of paragraph III.D.2(b) (ii) would apply even if the six month testing requirement of paragraph III.D.2(b) (i) had been satisfied. Subsequent containment entries while in OPERATIONAL CONDITION 4 would require retesting of the air lock utilized. Access to containment during periods when PRIMARY CONTAINMENT INTEGRITY is required by plant Technical Specifications is governed by paragraph III.D 2(b) (iii).

The existing air lock doors are so designed that a full pressure test at Pa of an entire air lock can only be i

aerformed after strongbacks (structural bracing) have seen installed on the inner door. This is because 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 are not designed to withstand such reverse forces.

Installing strongbacks, performing the test, and removing the strongbacks, is a cumbersome process requiring at least 12-14 hours during which access through the air lock is prohibited.

The periodic 6-month test requirement of paragraph III.D.2(b)(1) of Appendix J and the 3-day test requirement of paragraph III.D.2(b)(iii) of Appendix J provide assurance that the air lock will not leak excessively if no maintenance which could affect the ability of the airlock to seal has been performed on the air lock and if the air lock is properly engaged and sealed. An exemption from paragraph III.D.2(b)(ii) of Appendix J is requested since the proposed CPS Technical Specifications (attached) are substantially as safe as the requirement itself and do not endanger life or property. This exemption is included as a part of the NRC Standard Technical Specifications (NUREG-0123) and is consistent with current regulatory practice and policy.

Because of Technical Specification surveillance requirements, the requested exemption involves a de facto requirement for an air lock seal test in lieu of the III.D.2(b)(ii) test. Appendix J Paragraph III.D.2(b)(iii) already allows an air lock seal test in lieu of a similar required air lock test at a pressure

'U400296 L3 0- 85 ( 12-09 )-L 1A.120 of not less than Pa. Thus the functional equivalence of these tests under similar circumstances has been recognized. IP proposes an alternative test to be conducted during those periods when PRIMARY CONTAINMENT INTEGRITY is not required by the Plant Technical Specifications and prior to entering OPERATIONAL CONDITION 3. The alternative test consists of testing the seals of the inner and outer doors by pressurizing the area between the seals to Pa (9.0 psig) and verifying an acceptable leakage rate of 5 scfh. If, however, maintenance has been performed on the air lock since the last successful test performed pursuant to paragraph III.D.2(b) (i), an overall air lock test will be performed.

As a result, it can be concluded that there is reasonable assurance against undue air lock leakage provided under the exemption and no material increase in the probability or extent of air lock leakage is to be expected. Therefore, there is no significant increase in the probability of higher post-accident offsite or onsite doses related to the exemption and no significant increase in environmental impact beyond that experienced without an exemption.

B. Main Steam Isolation Valves (MSIVs) 10CFR50, Appendix J, Paragraph III.C.3 requires that the measured MSIV leak rates be included in the summation of the local leak rate test results. An exemption is requested to exclude the measured leakage from the combined local leak rate test results.

The MSIV Leakage Control System is designed to control and minimize the release of fission products that could leak through the closed MSIVs after a Loss of Coolant Accident (LOCA) by maintaining a negative pressure between the MSIVs. The effluent will be discharged into a volume where it will be processed by the standby gas treatment system before being released to the environs. A radiological analysis including this potential source of containment atmosphere leakage (28 scfh per steamline) was performed and the results documented in the CPS FSAR Chapter 15. The MSIVs will be periodically leak rate tested to verify that the leakage assumed in the radiological analysis is not exceeded per CPS Technical Specification 3.6.1.2.c.

Supplement #2 to the NRC CPS Safety Evaluation Report (SSER f2), Section 6.2.6 addresses the proposed MSIV leak test program. As noted on SSER 12 page 6-7, the proposed program is acceptable to the Staff. Also, SSER #2, Section 6.7 concludes that the design of the MSIV Leakage Control System at CPS is acceptable.

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U400296 L30 - 85 ( 12-09 )-L 1A.120 An exemption from paragraph III.C.3 of Appendix J is requested since the proposed Technical Specification is substantially as safe as the requirement itself and does not endanger life or property. This exemption is included as part of the NRC Standard Technical Specifications (NUREG-0123) and is consistent with current regulatory practice and policy. Therefore, literal compliance with Appendix J for this item is unwarranted.

The proposed CPS Technical Specification requirements (attached) provide reasonable assurance against undue MSIV leakage and no material increase in the probability or extent of MSIV leakage is to be expected. Therefore, there is no significant increase in the probability of higher post-accident offsite or onsite doses related to the exemption and no significant increase in environmental impact beyond that experienced with no exemption.

III. The Requested Exemptions Will Not Endanger the Common Defense and Security These requests will have no impact on the common defense and security.

IV. The Requested Exemptions are in the Public Interest If literal compliance with the applicable provisions of Appendix J discussed in Section II above were mandated, either cumbersome, unwarranted or more time conse-ing methods would have to be used or major design c' 'ges would be required. If design changes were und _taken, a considerable delay in the fuel load of CPS auld be occasioned at this stage. Any delay in the fuel load of CPS would, in turn, cause the cost of the unit to increase. Literal compliance with these Appendix J requirements would not result in any measurable difference in protection to the public health and safety relative to the protection afforded if the exemptions are granted. On balance, granting these exemptions is in the public interest.

Notes 1 Order, Long Island Lighting Company (Shoreham Nuclear Power Station, Unit 1), CLI-84-8, May 6, 1984.

2 Staff Requirements Memorandum MB40725A, July 25, 1984.

3 See: U.S. vs. Allegheny-Ludlum Steel Corp., 406 U.S. 1 742, 733-(1972)

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,j CONTAINMENT SYSTE.uS CONTAINMENT LEAUGE LIMITING CONDITIGN FOR OP.ERATION r

3. 6.1. 2 Containment leakage rates shall be limitac to: -

a. An overall integratad leakage rate of less than or equal to:- -- - ".

1. La, 0.55 percent by weight of the containment air per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at Pa, 9.0 psig.

b. A combined leakage rate of less than or equal to 0.60 La, for all penetra-tions4and all valves sucject to Type a and C tests when pressurized to Pa, 9.0 psig. A exe,pt 4,. main steant :sola Hcn ved ve.[

c. 4 Less than or equal to 28 scf per hour for any one main steam line through the isolation valves when tested at Pa, 9.0 psig.

d. A combined leakage rate of less than or equal to 0.08 La, for all penetra-tions shown in Table 3.6.4-1 of Specification 3.6.4 as seconcary contain-ment bypass Itakage paths when pressurized to Pa 9.0 psig.

e. A combined leakage rate of less than or equal to 1 gpm times the total number of ECCS and RCIC containment isolation valves in hydrostatically

. tested lines which penetrate the primary containment, when tested at

. 1.10 Pa, 9.9 psig.

• y APPLICABILITY: OPERATIONAL CONDITICNS 1, 2**and 3.

ACTION:

With:

a. The measured overall integrated containment leakage rate exceeding 0.75 La, or

b. The measured combined leakage rate for all penetrations and all valves subject to Type 8 and C tests execeding 0.60 La, or

c. The measured leakage rate exceeding 28 scf per hour for all four main steam lines through the isolation valves, or

d. The combined leakage rate for all penetrations shown in Table 3.5.4-1 as secondary containment bypass leakage paths exceeding 0.08 La; or

e. The measured combined leakage rate for all ECCS and RCIC containment isolation valves in hydrostatically tested lines which penetrate the pri-sery containment exceeding 1, g;m times the total numoer of suca valves,

n. IEnemph io Appedix J d toCFR 50 .

1. "See Special rest Exceotion 3.10.1. '

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) CCNTAINMENT SYSTEMS .

SURVEILLANCE REOUIREMENTS

4. 6.1. 3 Each containment air lock shall be demonstrated OPERABLE:

a. Within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> following each closing, except when the air lock is being M' 88gg used for multiole entries, then at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />,'iby verifying - -

j leakage ratehless than or equal to 5 scf per hour when tne gap . -

p V y seatbetween the door seals is pressurized to Pa, 9.0 psig.

an fo N b. W By c:nducting an overall air lock leakage test at Pa, 9.0 psig, and verifying that the overall air lock leakage rate is within its limit:

1. At least once per 6 months # ,

2. Prior to establishing PRIMARY CONTAINMENT INTEGRITY when maintenance

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has been performed on the air lock that could affect the air lock sealing capability.

c. At least once per 6 months by verifying that only one door in each air lock can be opened at a time.

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1. The provisions of Specification 4.0.2 are not applicable.

• EF A w p fi on fo Appaidw . J'o f 10 CFR. 5 0 .

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