ML20141G651
| ML20141G651 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 05/19/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20141G624 | List: |
| References | |
| NUDOCS 9705220442 | |
| Download: ML20141G651 (4) | |
Text
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- y %" UNITED STATES . I s NUCLEAR REGULATORY COMMISSION i M WASHINGTON, D.C. 30006 0001 i S j g%++ l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION I I
RELATED TO AMENDMENT NO. 158 TO FACILITY OPERATING LICENSE NO. DPR-3E !
MAINE YANKEE ATOMIC POWER COMPANY
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MAINE YANKEE ATOMIC POWER STATION DOCKET NO. 50-309 1.0- INTRODUCTION .j r , i
! By application dated September 13, 1996,'as supplemented by letter dated .i 1 ; January 15, 1997, Maine Yankee Atomic Power Company (the licensee) submitted a ;
- request for. changes to the Maine. Yankee Atomic. Power Station-(MYAPS) Technical 'i Specifications (TSs). The proposed changes would permit implementation of 10 !
CFR Part 50_ Appendix J, Option B. The licensee has proposed changes to the j
.TSs which include a reference-to Regulatory Guide 1.163, " Performance-Based j Containment Leak Test Program," dated September 1995, which specifies a method ;
acceptable to the NRC for complying with Option B. J
- The January 15, 1997, supplemental letter relocated the phrase "as modified by J approved exemptions" to follow " Appendix J, Option B" in TS 4.4.I.1, 4.4.11.1, t
- 4.4.11.2 and 4.4.II.3. - This supplemental letter provided clarifying information and did not change the staff's original no significant hazards i consideration determination published in the Federal Reaister on November 6,
, 1996 (61 FR 57487). >
2.0 BACKGROUND
Compliance with Appendix J provides assurance that the primary containment, j
! including those systems and components which penetrate the primary 4 L containment, do not exceed the allowable leakage rate specified in the TSs and ;
Bases. The allowable leakage rate is determined so that the leakage rate assumed in the safety analyses is not exceeded. . ,
l On February 4,1992, the NRC published a notice in the Egd.en1 Reaister (57 FR !
4166) discussing a planned initiative to begin eliminating requirements _
marginal to' safety.which impose a significant regulatory burden. Appendix J, 4
, " Primary Containment Leakage Testing for Water-Cooled Power Reactors," of ;
10 CFR'Part 50 was considered for this initiative and the NRC staff undertook n a study of possible changes to this regulation. The study examined the previous performance history of domestic containments and examined the effect ;
on risk of a revision to the requirements of Appendix J. The results of this t study.are reported in NUREG-1493, " Performance-Based Leak-Test Program."
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) Based on the results of this study, the NRC staff developed a performance-based approach to containment leakage rate testing. On September 12, 1995, ,
! the NRC approved issuance of this revision to 10 CFR Part 50, Apper. dix J, '
which was subsequently published in the Federal Reaister on September 26,
- - 1995, and became effective on October 26, 1995. The revision added Option B,
" Performance-Based Requirements," to Appendix J to allow licensees to voluntarily replace the prescriptive testing requirements of Appendix J with l testing requirements based on both overall and individual component leakage i rate performance. '
- Performance-Based Containment Leak-Test Program," dated September 1995, was developed as a method acceptable to the NRC staff for implementing l
- Option B. This regulatory guide states that the Nuclear Energy Institute 1
- (NEI) guidance document NEI 94-01, Revision 0, " Industry Guideline for '
Implementing Performance-Based Option of 10 CFR Part 50, Appendix J," provides l l
methods acceptable to the NRC staff for complying with Option B with four l exceptions which are described therein. i Option B requires that the RG, or other implementation document used by a i
licensee to develop a performance-based leakage testing program, must be
- included,. by general reference, in the plant TSs. The licensee has referenced i RG 1.163, dated September 1995, in the proposed MYAPS TSs.
RG 1.163, dated September 1995, specifies an extension in Type A test i frequency to at least one test in 10 years based upon two consecutive i successful tests. Type B tests may be extended up to a maximum interval of 10
! years based upon completion of two consecutive successful tests and Type C i tests may be extended up to 5 years based on two consecutive successful tests.
, By letter dated October 20, 1995, NEI proposed TSs to implernent Option B. )
After some discussion, the NRC staff and NEI agreed on final TSs which were l transmitted to NEI in a letter dated November 2, 1995. These TSs are to serve i as a model for licensees to develop plant-specific TSs in preparing amendment i requests to implement Option B.
i In order for a licensee to determine the performance of each component,
, factors that are indicative of or affect performance, such as an administrative leakage limit, must be established. The administrative limit I is selected to be indicative of the potential onset of component degradation.
Although_these limits are subject to NRC inspection to assure that they are selected in a reasonable manner, they are not TS requirements. Failure to meet an administrative limit requires the licensee to return to the minimum i value of the test interval. l l
Option B requires that the licensee maintain records to show that the criteria l for Type A, B and C tests have been met. In addition, the licensee must l maintain comparisons of the performance of the overall containment system and j
. the individual components to show that the test intervals are adequate. These ;
' records are subject to NRC inspection, j i
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_3-3.0 EVALUATION The. licensee's September 13, 1996, letter proposed TS changes to permit the 7 use of Option B of the revised 10 CFR Part 50, Appendix J. Option B permits a licensee to choose Type A; or Type B and C; or Type A, B, and C; testing to be done on a performance basis. The licensee has elected to perform Type A, B, and C testing on a performance basis. The TS changes refer to Regulatory Guide 1.163, " Performance-Based Containment Leak Test Program," dated September 1995, which specifies methods acceptable to the NRC for complying with Option B. This requires changes to existing TS 4.4.I ana 4.4.11 and the corresponding Basis.
The proposed changes will revise the Maine Yankee containment testing TSs to implement 10 CFR 50, Appendix J, Option B, for Type A integrated containment leak rate tests as well as Types B and C containment leakage rate tests. The definitions leakage rateforatP,)(containment P ,L (measured reduced test leakage pressure),
during L,(maximura preoperat ional testallowable at selected reduced p,ress,u,re P,), L,, (measured leakage during preoperational testing at accident pressure P ) were deleted from the TSs since Option B no longer allows the use of reduc,ed pressure tests and these definitions are no longer required. Also, the definitions for P and L, were revised to be ,
consistent with the definitions in Option B. ,The test pressure value was 1 conservatively assumed to be equal to the containment design pressure of 55 !
psig to bound the containment peak accident pressure (P,) while re-analysis of i the peak containment pressure is ongoing. Accordingly, the allowable leak '
rate for the air lock test in TS 4.4.II.3 and the definition of L in the basis section which are dependent on the value of P, were simpliffed as a 1 function of L,. ;
As noted above, the calculated design basis peak containment accident pressure is 50 psig. Maine Yankee is currently performing a reanalysis of containment performance following a postulated design basis loss-of-coolant accident. i Pending the results of this reanalysis, the licensee has conservatively i assumed that the peak accident pressure might approach the design pressure of !
the containment, which is 55 psig, and will be using this value in any " full- !
pressure" test until the reanalysis determines the actual calculated peak 4 containment pressure. The 1988 Integrated Leak Rate Test (ILRT) was a " Full-Pressure Test" conducted at 50 psig, which is the peak accident pressure in the current TSs and the TSs in effect in 1988. A partial pressure test was !
conducted in 1992, as permitted by 10 CFR 50, Appendix J at that time. Option
- B permits the test interval for the ILRT to be extended to 10 years following two consecutive successful tests. However, at least one of these tests must be at full pressure. The licensee's 1988 and 1992 tests satisfy this requirement. In their letter of January 15, 1997, the licensee requested NRC ,
concurrence in their position that the 1988 ILRT was a full-pressure test. !
This was the " full-pressure" in the TS at the time the test was conducted and is still the " full pressure" until this amendment is issued and the TSs are revised to increase the " full pressure" to 55 psig. Therefore, the staff agrees with the licensee's position.
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_4 These TS changes replace specific surveillance requirements related to containment leakage rate testing and the corresponding acceptance criteria and test methods with a requirement to perform the required testing as required by 10 CFR Part S0, Appendix J, Option B, as modified by approved exemptions, and in accordance with the guidelines contained in Regulatory Guide 1.163, dated September 1995. The licensee chose not to include its performance-based testing program in the TS as an administrative program, as was proposed in the November 2, 1995, letter to NEI discussed above. The November 2, 1995, letter provided guidance to licensees but is not an NRC requirement. The staff has reviewed the licensee's proposed TS changes and finds them consistent with the requirements of 10 CFR Part 50, Appendix J, Option B, in that the changes include general reference in the TS to the regulatory guide used by the licensee to develop the performance-based leakage-testing program for Maine Yankee. The staff therefore concludes that the licensee's request to implement 10 CFR Part 50, Appendix J, Option B, is acceptable.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Maine State official was notified of the proposed issuance of the amendment. The State official provided comments in a letter dated April 15, 1997. The staff responded to
- the State comments in a letter dated May 19, 1997.
5.0 ENVIRONMENTAt CONSIDERATION The amendment changes a requirement with respect to installation or u:;e of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazaros consideration, and there hts been no public comment on such finding .
(61 FR 57487). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment n'eed be prepared in connection with the issuance of the amendment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the propcsed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: R. Lobel R. Clark Date: May 19, 1997 .
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