ML20097F221
| ML20097F221 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 02/05/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20097F208 | List: |
| References | |
| NUDOCS 9602150340 | |
| Download: ML20097F221 (4) | |
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'4 UNITED STATES g
j NUCLEAR REGULATORY COMMISSION o
WASHINGTON, D.C. 2000H001
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION j
RELATED TO AMENDMENT NO. 217 TO FACILITY OPERATING LICENSE NO. DPR-77 AND AMENDMENT NO. 207 TO FACILITY OPERATING LICENSE NO. DPR-79 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT. UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328
1.0 INTRODUCTION
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 or. October 26, 1995.
The NRC added Option B " Performance-Based Requirements" to allow licensees to voluntarily replace the prescriptive testing requirements of 10 CFR 50 Appendix J with testing requirements based on both overall performance and the performance of individual components.
By letter dated December 8,1995, Tennessee Valley Authority, the licensee for Sequoyah Nuclear Plant Units 1 and 2, applied for amendments to Facility Licenses DPR-77 and DPR-78. 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 technical specifications. The program references Regulatory Guide 1.163, September 1995, " Performance-Based Containment Leak Test Program," which specifies a method acceptable to the NRC for complying with Option B.
2.0 BACKGROUND
Compliance with 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 the technical specifications and bases. The allowable leakage rate is determined so that the 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.
10 CFR 50 Appendix J, " Primary Containment Leakage Testing for Water-Cooled Power Reactors" was considered for this initiative and the staff undertook a study of possible changes to this regulation. The study examined the previous ENCLOSURE 3 9602150340 960205 PDR ADOCK 05000327 P
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. 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 ap) roved issuance of this revision to 10 CFR Part 50, Appendix J, which was suasequently 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.
Regulatory Guide 1.163, September 1995, " Performance-Based Containment Leak Test Program," 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.
Option B requires that the regulatory guide or other implementation document used by a licensee to develop a performance-based leakage testing program must be included, by general reference, in the plant technical specifications in preparing amendment requests to implement Option B.
The licensee has referenced Regulatory Guide 1.163 in the Sequoyah technical specifications.
Regulatory Guide 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 extended up to a maximum of 10 years based upon completion of two consecutive successful tests and Type C tests may be extended up to 5 years based on two consecutive successful tests.
By letter dated October 20, 1995, NEI proposed technical specifications to implement Option B.
After some discussion, the staff and NEI agreed on a set of model technical specifications which were transmitted to NEI in a letter dated November 2, 1995. These technical specifications are to serve as a model for licensees to develop plant-specific technical specifications in preparing amendment requests to implement Option B.
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 is selected to be indicative of the potentid 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 technical specifications requirements.
Failure to meet an administrative limit requires the licensee to return to the minimum value of the test interval.
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. 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.
3.0 EVALUATION The licensee's December 8,1995, letter to the NRC proposes to establish a "Containmer: Lakage Rate Testing Program" and proposes to add this program to the techniul specifications. The program references Regulatory Guide 1.163, September 1995, " Performance-Based Containment Leak Test Program," which specifies methods acceptable to t > NP' for complying with Option B.
This requires a change to existing teumical specifications 4.6.1.1.c, 3.6.1.2, 4.6.1.2.a, 3.6.1.3, 4.6.1.3, 4.6.1.6, 3.6.1.9, and 3.6.3 and the addition of the program to Section 6.8.4 to add the " Containment Leakage Rate Testing Program" as item h.
Corresponding bases were also modified.
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 technical specifications changes proposed by the licensee are in compliance with the requirements of Option B and consistent with the guidance of Regulatory Guide 1.163 and the generic technical specifications of the November 2,1995 letter and are, therefore, acceptable.
In addition to changes related to the adoption of Option B to Appendix J, the licensee also proposes to add a note to Technical Specification 3.6.1.3 which states:
An inoperable air lock door does not invalidate the previous successful performance of the overall air lock leakage test.
This note is included in the Improved Standard Technical Specifications, NUREG-1431. Since either air lock door is capable of providing a fission product barrier in the event of a design basis accident, there are situations in which one inoperable door does not result in the air lock being inoperable.
The licensee provides two examples:
(1) failure of an interlock mechanism and (2) seal leakage from a single door as instances which would not affect the integrity of the second air lock door or invalidate the previous overall air lock leakage test results.
Since the change is consistent with the Improved Standard Technical Specifications and maintains the plant within its design basis, the staff finds this change acceptable.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Tennessee State official was notified of the proposed issuance of the amendment. The State official had no comments.
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5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. 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 hazards consideration, and there has been no public comment on such finding (61 FR 182). 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 need be prepared in connection with the issuance of the amendment.
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6.0 CONCLUSION
l 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 amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: Richard M. Lobel Dated: February 5,1996
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