ML16138A710
| ML16138A710 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 11/13/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML16138A711 | List: |
| References | |
| NUDOCS 9011190046 | |
| Download: ML16138A710 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 185TO FACILITY OPERATING LICENSE DPR-38 AMENDMENT NO. 185TO FACILITY OPERATING LICENSE DPR-47 AMENDMENT NO.182 TO FACILITY OPERATING LICENSE DPR-55 DUKE POWER COMPANY OCONEE NUCLEAR STATION, UNITS 1, 2 AND 3 DOCKET NOS. 50-269, 50-270 AND 50-287
1.0 INTRODUCTION
By letter dated May 31, 1988, as revised and supplemented April 26, June 5 and August 1, 1990, Duke Power Company (the licensee) proposed amendments to the Technical Specifications (TSs) for the Oconee Nuclear Station, Units 1, 2 and 3. The proposed amendments would revise the TSs concerning allowable limits on primary-to-secondary leakage.
2.0 EVALUATION Specification 3.1.6.4 of the current Oconee TSs requires that if the leakage through the Oconee Unit I steam generator tubes equals or exceeds 0.3 gallons per minute (gpm), a reactor shutdown shall be initiated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and the reactor shall be in cold shutdown within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Specification
.3.1.6.4 further requires that if leakage at Unit 1 is less than 0.3 gpm, an assessment shall be made whether operations may be continued safely or the plant should be shut down. In either case, the Specification requires the NRC to be notified in accordance with 10 CFR 50.73. Specification 3.1.6.4 for Oconee Unit 1 dates back to the 1970's when Unit 1 was experiencing frequent leakage problems.
Under the current Oconee TSs, Specification 3.1.6.4 is not applicable to Oconee Units 2 and 3. Apart from Specification 3.1.6.1 which limits total reactor coolant leakage to 10 gpm, Oconee Units 2 and 3 do not have specific limits on allowable primary-to-secondary leakage in the Oconee TSs.
The licensee is proposing a change to Specification 3.1.6.4 to make it applicable to Oconee Units 1, 2 and 3, rather than to just Unit 1. Under the proposed change, leakage through the tubes of any one steam generator would be limited to 0.35 gpm in lieu of the present limit of 0.3 gpm for total leakage from both steam generators for Oconee Unit 1.
90/ 11190046 901113 PDR ADOCK 05000269 In*
PDIC
-2 The proposed 0.35 gpm limit is consistent with the NRC staff's recommendation in NRC Generic Letter 85-02 that all PWRs adopt leakage limits which are at least as restrictive as the Standard Technical Specification limits. The proposed limit is essentially identical with the 500 gallon-per-day (gpd) limit in the Standard Technical Specifications for Babcock & Wilcox (B&W) plants (NUREG-0103). The proposed limit is intended to provide assurance tPat steam generator tube integrity is maintained for the full spectrum of normal and postulated accident conditions (NUREG-0844). This limit also serves to provide added assurance that the dosage contribution for tube leakage will be limited to a small fraction of 10 CFR Part 100 limits for design basis accidents (e.g., main steam line break and steam generator tube rupture). This limit is within the 1.0 gpm total tube leakage (from both steam generators) assumed in the Oconee Final Safety Analysis Report (FSAR) Chapter 15, safety analyses.
The licensee also proposes to delete the sentence of Specification 3.1.6.4 which requires performance of an assessment for continued operation if leakage is less than the limit. This requirement is not included in either the Standard Technical Specifications or other plant TSs. Furthermore, the consequence of leaks less than 0.35 gpm are bounded by the results of the FSAR Chapter 15 safety analyses. In addition, the licensee notes that plant operating procedures require a reduction of power for steam generator tube leaks exceeding 0.2 gpm to reduce the leakage and its potential impact. The licensee states that these procedures are based on operating considerations, including practical limits to minimize secondary side contamination, and serve to restrict operation when significant primary-to-secondary leakage exists.
The licensee is proposing to delete the last sentence of Specification 3.1.6.4 which requires NRC notification pursuant to 10 CFR 50.73. However, notification of the NRC pursuant to 10 CFR 50.73 would remain a requirement in Specification 6.6.2.1 in the event that the leakage limits of Specification 3.1.6.4 are exceeded.
Since the deleted sentence is redundant, this change is acceptable.
Finally, this licensee is proposing an administrative change to correct outdated NRC organizational addresses in TS 4.17.6.a. No changes in requirements result from this change, and this is acceptable.
The proposed amendments to the Oconee TSs incorporate limits on allowable primary-to-secondary leakage which are consistent with limits in the Standard Technical Specifications for B&W plants. As reported in NUREG-0844, the NRC staff considers these limits to be an effective instrument for ensuring steam generator tube integrity for the full range of normal, transient, and postulated accidents and for ensuring this leakage is within values assumed in the FSAR safety analyses. The NRC staff, therefore, finds the proposed amendments acceptable.
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3.0 ENVIRONMENTAL CONSIDERATION
These amendments involve changes in requirements with respect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20. The amendments also relate to changes in recordkeeping, reporting, or administrative procedures or requirements. We have ddtermined that the amendments involve 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 these amendments involve no significant hazards consideration, and there has been no public comment on such finding. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9) and (10).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of these amendments.
4.0 CONCLUSION
The Commission's proposed determination that the amendments involve no significant hazards consideration was published in the Federal Register (55 FR 36340) on September 5, 1990. The Commission consulted with the State of South Carolina. No public comments were received, and the State of South Carolina did not have any comments.
We have 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, and (2) such activities will be conducted in compliance with the Commission's regulations, and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
E. Murphy, EMCB Dated:
November 13, 1990