ML17146A324
| ML17146A324 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 04/01/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17146A323 | List: |
| References | |
| NUDOCS 8604090027 | |
| Download: ML17146A324 (3) | |
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.
25 TO FACILITY OPERATING LICENSE NO.
NPF-22 PENNSYLVANIA POWER 5 LIGHT COMPANY SUSQUEHANNA STEAN ELECTRIC STATION UNIT 2
1.0 INTRODUCTION
DOCKFT NO. 50-388 The licensee proposed changes to the Technical Specifications of the oper-ating license for Susquehanna Steam Electric Station, Unit 2 to lower the setpoint for main steam isolation valve (NSIV) closure from low water level 2 (Level 2) to low water level 1 (Level 1).
2.0 EVALUATION The purpose of lowering the setpoint for MSIV closure is to reduce the number of challenges to the safety-relief valves (SRVs).
This modification is consistent with staff recommendations for resolving Action Plan Item II.K..3.16 "Reduction of Challenges and Failures of Relief Valves-Feasibility Studv and System Modifications."
The licensee reviewed the FSAR transient and accident analyses to assess the impact of the setpoint change on the events.
Thermal safety limits for those transients involving MSIV closure on low water level are not affected because the limiting thermal conditions are reached and reduced well before water level falls to Level 2.
For loss-of-coolant accidents involving loss of offsite power, NSIV closure will occur on the loss of power signal regardless of water level.
For a loss-of-coolant accident where offsite power is available, lowering the setpoint will delay closing of the NSIVs.
This will result in a more rapid depres-surization which leads to earlier iniection into the vessel by the low pressure Fmergency Core Cooling (ECC) systems.
The proposed modification will eliminate MSIV closures for many transient events where water level falls below Level 2 but is recovered prior to reaching Level 1.
This will reduce challenges to the safety-relief valves.
As discussed above, previously anal,yzed transients and accidents are not adversel.y impacted by the change.
For the above reasons, the proposed technical specification change is acceptable.
- 3. 0 ENVIRONMENTAL CONSIDERATION This amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The 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 SSOOO9OOn 860eoa PDR ADOCN, 05000388 P
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individual or cumulative occupational radiation exposure.
The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding.
Accordingly, this 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 assess-ment need be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
The Commission made a proposed determination that the amendment involves no significant hazards consideration which was published in the Federal Reqister (51 FR 6829) on February 26,
- 1986, and consulted with the Sta~te o
No public comments were received, and the State of Pennsylvania did not have any comments.
Me 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 this amendment will not be inimical to the 'common de<ense and security or to the health and safety of the public.
Principal Contributors:
George
- Thomas, Reactor Systems
- Branch, DBL Mari-Josette Campagnone, Proiect Directorate No. 3, DBL
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