ML17156A173
| ML17156A173 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 04/23/1985 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML17156A172 | List: |
| References | |
| NUDOCS 8504300049 | |
| Download: ML17156A173 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION AMENDMENT NO.
TO NPF-14 SUSQUEHANNA STEAM ELECTRIC STATION, UNIT 1 DOCKET NO. 50-387 Introduction The licensee proposed changes to the Technical Specifications of the operating license for Susquehanna Steam Electric Station, Unit 1 to lower the setpoint for main steam isolation valve (MSIV) closure from low water level 2 (Level 2) to low water level 1 (Level 1).
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 Study 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, HSIV closure will occur on the loss of power signal regardless of water level.
For loss-of-coolant accident where offsite power is available, lowering the setpoint will delay closing of the HSIVs.
This will result in a more rapid depressurization which leads to earlier injection into the vessel by the low pressure Emergency Core Cooling (ECC) systems.
The proposed modification will eliminate HSIV 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 analyzed transients and accidents are not adversely impacted by the change.
For the above reasons, the proposed technical specification change is acceptable.
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 SS04300049 86O4gp PDR ADOGK 05000387 PD~R
may be released offsiteand that there is no significant increase in indivi dual or cumulative occupational radiation exposure.
The Commission has previously issued a proposed finding that this amendment involves no signi ficant 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 assessment'need be prepared in conne'ction with the issuance of this amendment Conclusion 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 this amendment will not be inimical to the common defense and security or to the health and safety of the public Dated:
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