ML17056B046
| ML17056B046 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 10/11/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17056B045 | List: |
| References | |
| NUDOCS 9010240082 | |
| Download: ML17056B046 (4) | |
Text
><~lt ~t'Cut Wp0 ca e
Cj cv g'
O 0+
+g**+
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 e
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 22 TO FACILITY OPERATING LICENSE NO. NPF-69 NIAGARA MOHAWK POWER CORPORATION NINE MILE POINT NUCLEAR POWER STATION UNIT NO.
2 DOCKET NO. 50-410
1.0 INTRODUCTION
By letter dated July 19, 1990, Niagara Mohawk Power Corporation, the licensee for Nine Mile Point Nuclear Station, Unit 2, proposed changes to the plant Technical Specification (TS) Table 3.6.3-1, "Primary Containment Isolation Valves."
The proposed change to the table would allow hydrostatic leak rate testing for the emergency core cooling system (ECCS) and reactor core isolation cooling (RCIC) system isolation valves in lines that terminate below the suppression pool.
- 2. 0 EVALUATION Niagara Mohawk requested a change to the test method for the isolation valves associated with the following systems:
~Sstem Residual Heat Removal Pump Suction High Pressure Core Injection System Low Pressure Core Injection System Reactor Core Isolation Cooling System Valve Ne.
MOVI A, B, C, MOV 118 MOV 112 MOV 136 These valves are presently Type C tested using air, and Niagara Mohawk has proposed to revise TS Table 3.6.3-1 to permit hydrostatic leak testing of the above listed ECCS and RCIC System suppression pool isolation valves in lieu of the air test, on the basis that these lines terminate below the minimum torus water level and total valve leakage will be limited to 1 gpm times the total number of the above containment isolation valves.
The Acceptance Criteria of NUREG-0800, Standard Review Plan, Section 6.2.6, "Containment Leakage Testing," states that "Hydrostatic testing of containment isolation valves is permissible if the line is not a potential containment atmosphere leak path, and may be found acceptable if it can be demonstrated 90l0240082 90l0ll PDR ADOCK 050004l0 pcc
in accordance with the requirements of Section III.C of Appendix J, that a
liquid inventory is available to maintain a water seal (while assuming the single failure of any active component) during the post accident period.
Limits for liquid leakage should be assigned to these valves based on analysis and included in the plant Technical Specifications."
The ECCS and RCIC suction lines terminate below the calculated minimum post accident suppression pool water level.
Therefore, suppression pool water effectively seals the above containment isolation valves from the primary containment atmosphere thereby preventing gaseous releases to the primary containment during post-accident periods.
Niagara Mohawk has committed to hydrostatically leak test these valves to at least 1.10 Pa (43.73 psig).
The combined leakage value will be limited to less than or equal to 1 gpm times the total number of such containment isolation valves (as specified in the Technical Specifications).
Leakage results from the hydr ostatically tested valves will be excluded from the combined Types 8 and C leak rate calculations as allowed by Appendix J and the Technical Specifications.
The proposed test pressure and the specification of leakage limit for the above containment isolation valves complies with 10-CFR Part 50, Appendix J, Item III.C.3(a) and (b).
The staff has reviewed the proposed changes to the Technical Specifications and finds these changes to be acceptable.
- 3. 0 ENVIRONMENTAL CONSIDERATION This amendment involves a change in a requirement with respect to the installation or use of the facility components located within the restricted areas as defined in 10 CFR Part 20.
The staff has determined that this 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 Comission has previously issued a proposed finding that this amendment involves no significant'azards 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 connection with the issuance of this amendment.
- 4. 0 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:
October 11, 1990 PRINCIPAL CONTRIBUTOR:
aro
~ - v-c~