ML20116M800
| ML20116M800 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 08/13/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20116M793 | List: |
| References | |
| NUDOCS 9608210084 | |
| Download: ML20116M800 (4) | |
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UNITED STATES 2
E NUCLEAR REGULATORY COMMISSION f
WASHINGTON, D.C. 20666-0001
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 84 AND 71 TO FACILITY OPERATING LICENSE N05. NPF-76 AND NPF-80 HOUSTON LIGHTING & POWER COMPANY CITY PUBLIC SERVICE BOARD OF SAN ANTONIO CENTRAL POWER AND LIGHT COMPANY CITY OF AUSTIN. TEXAS DOCKET NOS. 50-498 AND 50-499 SOUTH TEXAS PROJECT. UNITS 1 AND 2
1.0 INTRODUCTION
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By application dated May 1,1996, Houston Lighting & Power Company, et al.,
(the licensee) requested changes to the Technical Specifications (TSs)
(Appendix A to Facility Operating License Nos. NPF-76 and NPF-80) for the South Texas Project, Units 1 and 2 (STP). The proposed changes to the TSs would implement 10 CFR Part 50, Appendix J, Option B, by referring to Regulatory Guide (RG) 1.163, " Performance-Based Containment Leak-Test Program."
2.0 BACKGROUND
On September 12, 1995, the U.S. Nuclear Regulatory Commission (NRC) approved issuance of a revision to 10 CFR Part 50, Appendix J, " Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors" which was subsequently published in the Federal Reaister on September 26, 1995, and became effective on October 26, 1995.
The NRC added Option B " Performance-Based Requirements
- to allow licensees to voluntarily replace the prescriptive testing requirements of 10 CFR Part 50, Appendix J, with testing requirements based on both overall leakage rate performance and the performance of individual components.
By application dated May 1, 1996, the licensee requested changes to the TSs for STP. The proposed changes would permit implementation of 10 CFR Part 50, Appendix J, Option B.
The licensee has established a " Containment Leakage Rate Testing Program" and proposed adding this program to the TSs.
The program references RG 1.163, " Performance-Based Containment Leak-Test Program," dated September 1995, which specifies a method acceptable to the NRC for complying with Option B.
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3.0 DISCUSSION Compliance with 10 CFR Part 50, Appendix J, provides assurance that the primary containment, including those systems and components which penetrate the primary containment, do not exceed the allowable leakage rate specified in j
the TSs and Bases. The allowable leakage rate is determined so that the 1
leakage assumed in the safety analyses is not exceeded.
On February 4,1992, the NRC published a notice in the Federal Reaister (57 FR 4166) discussing a planned initiative to begin eliminating requirements marginal to safety which impose a significant regulatory burden. Appendix J of 10 CFR Part 50 was considered for this initiative and the staff undertook 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 study are reported in NUREG-1493, " Performance-Based Leak-Test Program."
Based on the results of this study, the 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, Appendix 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 testing requirements based on both overall and individual component leakage rate performance.
RG 1.163, was developed as a method acceptable to the NRC staff for implementing Option B.
This regulatory guide states that the Nuclear Energy Institute (NEI) guidance document NEI 94-01, " Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J," provides methods acceptable to the NRC staff for complying with Option B with four exceptions which are described therein.
i Option B requires that the RG or other implementation document used by a j
licensee to develop a performance-based leakage rate testing progr w must be included, by general reference, in the plant TSs. The licensee has referenced RG 1.163 in the proposed TSs.
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RG 1.163 specifies an extension in Type A test frequency to at least one test in 10 years based upon two consecutive successful tests. Type B tests may be i
extended up to a maximum interval of 10 years based upon completion of two consecutive successful tests and Type C tests may be extended up to 5 years l
based on two consecutive successful tests.
By letter dated October 20, 1995, NEI proposed TSs to implement Option B.
j After some discussion, the staff and NEI agreed on final TSs which were i
enclosed to a letter from C. Grimes (NRC) to D. Modeen (NEI) dated November 2, i
1995. These TSs are to serve as a model for licensees to develop plant j
specific TSs in preparing amendment requests to implement Option B.
J
F 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 is selected to be indicative of the potential onset of component degradation. Although these j
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 value of the test interval.
Option B requires that the licensee maintain records to show that the criteria for Type A, B, and C tests have been met.
In addition, the licensee must maintain comparisons of the performance of the overall containment system and the individual components to show that the test intervals are adequate. These records are subject to NRC inspection.
4.0 EVALUATION The licensee's May 1, 1996, letter to the NRC proposes to establish a
" Containment Leakage Rate Testing Program" and proposes to add this program to the TSs. The program references RG 1.163, which specifies a method acceptable to the NRC for complying with Option B.
This requires a change to existing TSs 4.6.1.1, 3.6.1.2, 4.6.1.2, 3.6.1.3, 4.6.1.3, and the addition of the
" Containment Leakage Rate Testing Program" to Section 6.8.3.j.
Corresponding Bases were also modified as necessary.
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 perfom Type A, B, and C testing on a performance basis.
The proposed TS changes discussed above are in compliance with the requirements of Option B and consistent with the guidance of RG 1.163, and the generic TSs of the November 2,1995, letter and are, therefore, acceptable to the staff.
The licensee's May 1,1996, submittal also proposed revising TSs 4.6.1.7.2 and 4.6.1.7.3 dealing with the frequency of leakage rate testing the normal containment purge valves and the supplementary containment purge valves.
These valves use resilient seals. The licensee proposed to extend the present test intervals of 3 months for the supplementary purge valves and 6 months for the normal purge valves following the guidance of RG 1.163.
RG 1.163 recommends testing of containment purge and vent valves at intervals not exceeding 30 months. However, the current test intervals are not based on Appendix J considerations and'the licensee's proposal is therefore outside the scope of the proposed change to Option B.
The current test intervals are based on the findings of Generic Issue B-20, " Containment Leakage Due to Seal Degradation," that valves with resilient seals should be tested more frequently than required by Appendix J.
The background for this conclusion is discussed in IE Circular 77-11, " Leakage of Containment Isolation Valves With Resilient Seats," issued on September 6, 1977.
. After some discussions with the staff, the licensee chose not to pursue this issue further.
Since additional information would be required to continue this part of the review (for TSs 4.6.1.7.2 and 4.6.1.7.3), the staff denies this part of the proposed change.
5.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Texas State official was notified of the proposed issuance of the amendments. The State official had no comments.
6.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements.
The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released
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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 amendments involve no significant hazards consideration, and there has been no public comment on such finding (61 FR 28616). 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 j
need be prepared in connection with the issuance of the amendments.
7.0 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 proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
R. Lobel Date: August 13, 1996 i
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