ML20196A687

Application for Amends to Licenses DPR-77 & DPR-79, Consisting of Tech Spec Change 88-32,requesting Exemption from 10CFR50,App J to Allow Use of Mass Point Method for Calculating Containment Leakage Rates.Fee Paid

ML20196A687
Person / Time
Site:	Sequoyah
Issue date:	12/02/1988
From:	Michael Ray TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20196A692	List: ML20196A687 ML20196A703
References
TAC-R00503, TAC-R00504, TAC-R503, TAC-R504, NUDOCS 8812060072
Download: ML20196A687 (6)

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Oe ao . p TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 374ol SN 157B Lookout Place DEC 021988 TVA-SQN-TS-88-32 10 CFR 50.90 10 CFR 50.12 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk h1ashington, D.C. 20555 centlemen:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT (SQN) - TECHNICAL SPECIFICATION (TS) CHANGE 88-32 AND ASSOCIATED EXEMPTION REQUEST TO 10 CFR 50, APPENDIX J Pursuant. to 10 CFR 50.12, TVA requests an exemption from 10 CFR 50, Appendix J, paragraph III.A.3, which requires that type A (containment integrated leak rate) tests be performed in accordance with American National Standards Institute (ANSI) N45.4-1972, "Leakaso Rate Testing of Containment Structures for Nuclear Reactors." Since the issuance of ANSI N45.4-1972, a more accurate method of determining containnent leakago rates--the mass point method--was developed as described in ANSI 56.8-1987, "Containment System Leakage Tosting Requirements." TVA is reqJesting an exemption to allow use of the mass point method for calculating con'.;ainment leakage rates.

Enclosure 1 provides the justification and conclusion that the exemption from the requirements of Appendix J, paragraph III.A.3, is justified pursuant to 10 CFR 50.12(a)(1) and 10 CFR 50.12(a)(2)(Li) in that it la authorized by law; will not present undue risk to pubile health and safety; and is consistent with the common defense and security. In addLtion, application of the regulation in this particular circumstanco would not serve the underlying purpose of the rule and is not necessary to athleve the undorlying purposo of the rule. The mass point method will satisfy ihe accuracy requirements of 10 CFR 50, Appendix J, paragraph III.A.3, for typo A tests. Enclosure 1 also contains an environmental assessment, which conct', dos that there would be no significant environmental lepact associated with the proposed exemption.

Enclosure 2 contains a change to the SQN TSo, which is regulrod in order to reflect the subject exemption request. Enclosure 3 contains the justification for the change, and enclosure 4 contains the determination of no significant hazards consideration pursuant to 10 CFR 50.92.

It is requestod that the proposed exemption request and proposed TS change be acted upon by February 1,1989, so that the n4xt type A test for unit 2 (scheduled for March 1939) can utilize the mass point method.

Enclosed is a check for the $150 amendment app 1Leation feo required by 10 CFR 170.12.

i 8812060072 881202 PDR P

ADOCK 05000327 A

Q\ \ h k.h h PDC ' h An Equal Opportunity Employer \ 5\j *h

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. 2-U.S. Nuclear Regulatory Comission C 02 5 [

Please direct questions concerning this issue to D. V. Goodin at t (615, 843-7734.

Very truly yours.

TENNESSEE VALLEY AUTHORITY .

v p !\ ,

M. J., ay, Manager ,.

Site f.icensing Staff .

Sworn d before me this a day o subscrf'.p/6 of / / 1988 Add /)sst / 0]j D

, Ilotary Public

• My comi ion Expires. I, M Enclosures cc: S*ee page 3 i

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. U.S. Nuclear Regulatory Commission gg

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cc (Rnclosures):

Ms. S. C. Black, Assistant Director for Projects TVA Projects Division U.S. Nuclear Regulatory Commission one White Filnt, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. F. R. McCoy, Assistant Director for Inspection Programs TVA Projects Division U.S. Nuclear Regulatory Commission Region II 101 1.arietta Street, NW, Sulle 2900 Atlanta, Georgia 30323 Mr. Michael H. Mobley, DLeector (w/o enclosures)

DLvision of Radiological Health T.E.R.R.A. Building 150 9th Avenue, N Washville, Tennessee 37203 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy. Tennessee 37379 American Nuclear Insurers Attention: Librarlan The Exchange, Suite 245 270 Farmington Avenuo Farmington, Connectlcut 06032

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ENCLOSURE 1 JUSTIFICATION FOR EXEMPTION FROM 10 CFR 50, APPENDIX J. PARAGRAPH III.A.3 SQN UNITS 1 AND 2

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EXEMPTION REQUEST AND ENVIRONMENTAL ASSESSMENT

Background

10 CFR 50, Appendix J, was issued in 1973 to establish requirements for primary reactor containment leakage testing. Appendix J incorporated, by reference, ANSI N45.4-1972, "Leakage Rate Testing of Containment Structures for Nuclear Reactors." This standard requires that containment leakage calculations be performed using the point-to-point method or total-time method. A new statistical technique known as the mass point method was incorporated into r newer ANSI 6candard (reference: ANSI /ANS 56.S-1987, "Containment Syst9m Leakage Testing Requirements"). The newer ,

standard has been accepted by NRC staff as an improved alternative method

• i of calculating containment leakage rates. NRC published for public comment a proposed rule, which provided a limited revision to Appendix J

. requirements that allows utilities to use the mass point method under current regulations. this limited revision was published in the l February 29, 1995 t'ederal Register Volume 53, No. 39. TVA supported the proposed rule and provided comments by letter dated April 4, 1988.

Justification TVA considers this exemption to be justified based on 10 CFR 50.12(a)(2)(ii): 1.e., application of the regulatic, in the l particular circumstances is not necessary to achieve the underlying purpose of the rule, which is to provide an accurate and conservative test of containment integrity. This request is consistent with the proposed rule as published in the February 1988 Federal Register, which revised 10 CFR 50, Appendix J, to allow the use of the mass point method for calculating the type A leakage rate. It is important to note that TVA is not considering a test duration of less than the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> stipulated in the proposed rule. IVA previously commented on the proposed rule in an April 4, 1988 letter that supported using a test duration of less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. TVA does not propose to change the 24-hour test duration for employing the mass point method with this change.

TVA has conducted containment leak rate tests at SQN since 1979 and has used the mass point method as well as the required total-time method and point-to-point method. The test data clearly indicate that accurate results can be obtained using the mass point method. Consequently, TVA believes that this exemption request will not result in undue risk to the health or safety of the public. In addition, the proposed exemption does l not change existing plant safety limits, safety settings, systems, or (

operation, nor does it impact the design basis of the containment  !

structure or modify its response during a design basis accident (DBA).

l In addition to the above justification. TVA is providing the following environmental assessment and finding of no significant impact.

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Environmental Assessment

1. Identification of the proposed action: TVA is requesting an exemption to 10 CFR 50, Appendix J, section III.A.3, which requires type A (containment integrated leak rate) tests to be performed in accordance with ANSI N45.4-1972. Since the issuance of ANSI N45.4-1972, a more accurate method of determining containment leakage rates--the mass point method--was developed as described in ANSI 56.8-1987. TVA is proposing an exemption to 10 CFR 50, Appendix J, to allow use of the mass point method for calculating containment leakage rates.

2. The need for the proposed action: The proposed exemption is needed to permit the use of an improved, more accurate method for calculating containment leakage. Specific wording of Appendix J, section III.A.3, which references the older ANSI standard, would preclude use of the newer, improved mass point method. The mass point method is considered to be a superior method for calculating containment leakage rates and thereby a better method of verifying that leakage from containment is maintained within allowable limits. By employing a more reliable calculation technique, the assessment of containment integrity through integrated leak rate testing is enhanced.

3. Environmental impact of the proposed action The proposed exemption would have no environmental impact because the change does not involve a modification to the plant safety limits or modify the design basis of the containment structure. Because the mass point method raises the reliability for assessing containment integrity, the degree of confidence in containment integrity is enhanced.

4. Alternative to the proposed action: The aernative to the proposed exemption request would be to comply with the current standard and evaluate containment test results vaing the total-time method and the (

j point-to-point method. These methods are considered to be acceptable  ;

by NRC staffi however, the original intent of Appendix J to use t state-of-the-art leak test methodology would be unnecessaril) I restricted.  !

5. Alternative use of resources: The proposed exemption does not involve the use of additional resources considered previously in connection with the "Final Environmental Statement Related to the Operation of l Sequoyah Nuclear Plant Units 1 and 2." dated July 1974 I

6. Finding of no significant impact: TVA finds no basis for preparing an j environmental impact statement for the proposed exemption request.  ;

Based on the above entironmental assessment, we conclude that the i exemption will not hav3 an effect on the quality of the human r environment. (

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