ML13316A578
| ML13316A578 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/17/1984 |
| From: | Paulson W Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML13316A575 | List: |
| References | |
| TAC-52165, NUDOCS 8402220495 | |
| Download: ML13316A578 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 72 TO PROVISIONAL OPERATING LICENSE NO. DPR-13 SOUTHERN CALIFORNIA EDISON COMPANY SAN ONOFRE NUCLEAR GENERATING STATION, UNIT NO. 1 DOCKET NO. 50-206
1.0 INTRODUCTION
By letter dated August 10, 1983, Southern California Edison Company (the licensee) proposed changes to the TechnicalSpecifications for San Onofre Nuclear Generating Station, Unit No. 1. These changes
.would (1) increase the safety injection trip setpoint for "Pressurizer Pressure-Low" in Table 3.5.5-2 from > 1685 psig to > 1735 psig, and (2) modify the descriptive material in Section 5 of the Technical Specifications with updated information reoarding (a) the addition of the Sphere Enclosure Building around the containment, (b) pressure temperature capability of the containment following postulated rupture of the primary or secondary cooling system, and (c) the range of the neutron monitoring instrumentation.
A Notice of Consideration of Issuance of Amendment and Proposed No Significant Hazards Consideration Determination and Opportunity for Hearing related to the requested action was published in the Federal Register on October 26, 1983 (48 FR 49596). A request for hearing and public comments were not received.
2.0 DISCUSSION AND EVALUATION 2.1 Proposed Increase in the Safety Injection Trip Setpoint for "Pressurizer Pressure-Low" Table 3.5.5-2, "Containment Isolation Instrumentation Trip Set Points" specifies that the safety injection trip for "Pressurizer Pressure Low" should be set > 1685 psig.
The licensee's submittal states that this setpoint does not take into account instrumentation error.
The reactor manufacturer's recommendation is to include an allowance for 3% instrumentation error; therefore, the setpoint should be >
1735 psig. This increased setpoint is more conservative because a trip will occur sooner.---In.the case of a loss of coolant accident 8402220495 840217 PDR ADOCK 05000206 P
-2 for example, as the primary system pressure decreases the trip at 1735 psig will occur sooner than it would if the setpoint were 1685 psig. Based on its review, the NRC staff concludes that this increased setpoint is acceptable.
2.2 Update Descriptive Material in Section 5 of the Technical Specifications Section 5 of the Technical Specifications contains descriptive material regarding San Onofre Unit No. 1. The licensee has proposed changes to update this descriptive material.
These proposed changes do not impact the limiting conditions for operation nor the surveillance requirements of the technical specifications. The descriptive changes reflect the addition of a sphere enclosure building around the containment and a slight modification in the description of the minimum distance to the exclusion boundary (283.5 meters from the outer edge of the containment sphere versus 283 meters in the present Technical Specification); updated values of the pressure and temperature capability of the containment based on recent analyses and the current setpoint for containment isolation upon high pressure in the containment; and a revision to the description of the neutron monitor instrumentation to indicate a range from fully shutdown to 200% of full power (versus 100% of full power in the current tech nical specifications).
Durina the review of the proposed changes to Section 5, the NRC staff suggested two modifications. These were (1) a slight change to the wording in Section 5.2 (page 62) to indicate that the containment is "capable of withstanding" a maximum internal pressure of 53.3 psig, a temperature of 391.5oF, and an..., and (2) retaining the current wording of the "Basis" section on page 63. In this latter case, the capability of the containment to withstand the 53.3 psig and 391.5 0F pressure and temperature conditions simultaneously with an earthquake having a maximum ground acceleration of 0.67g is still under review in the Systematic Evaluation Program. Accordingly, the staff finds that it is premature to incorporate this revised description in the Technical Specifications at this time. Both of these changes were discussed with the licensee and we mutually agreed to them. Neither of these chanaes to Section 5.2 affect the safety of the plant because they are merely descriptive in nature.
Based on its review, the NRC staff finds these descriptive changes acceptable.
0 ENVIRONMENTAL CONSIDERATION The staff has determined that the amendment does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact. Having made this determination, the staff has further concluded that the amendment involves
-3 an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR §51.5(d)(4), that an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
The staff 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; and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
5.0 ACKNOWLEDGEMENT W. Paulson prepared this evaluation.
Dated: February 17, 1984