ML20099G334
| ML20099G334 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 07/31/1992 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20099G332 | List: |
| References | |
| NUDOCS 9208140223 | |
| Download: ML20099G334 (3) | |
Text
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UNITED STATES
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SAffTY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGUL61LQH RELATED TO AMQ RMENT NO. 85 TO FACILITY OPERATING LICENSE NO. NPF-43 DETROIT EDIS0N COMPANY FERMI-2 DOCKET NO. 50-341
1.0 INTRODUCTION
By letter dated January 30, 1992, the Detroit Edison Company (Deco or the licensee) requested amendment to the Technical Specifications (TS) appended to Facility Operating License No. NPF-43 for Fermi-2.
The proposed amendment would remove two valves from TS Table 3.4.3.2-1 ana 3.4.3.2-2 because these valves are no longer reactor coolant system pressure boundary isolation valves.
2.0 EVALVATION The elimination of two valves from the above TS tables will have the effect of elimit.ating the surveillance requirements for these valves. The two valves in question, the reactor pressure vessel (RPV) head spray inboard isolation valve (Ell-F022) and the RPV head spray outboard isolation valve (Ell-F023).
The RPV head spray line has previously been permanently disconnected (flanged) from the reactor vessel and, therefore, these valves no lu.ger perform a reactor coolant system pressure boundary isolation function. Thus, it is
. appropriate to eliminate these valves from TS Table 3.4.3.2-1, " Reactor Coolant System Pressure Isolation Valves" and Table 3.4.3.2-2, " Reactor Coolant System Interface Valves Leakage Pressure Monitors."
The RPV head spray feature was an operating mode for the Residual Heat Removal (RHR) System associated with the RHR shutdown cooling mode. When RHR is o'erating in the shutdown cooling mode, reactor coolant is returned to the RPV a
tirough a recirculation system loop, or wi~ N head spray installed, part of the flow could be diverted to a spray nozzle in the RPV h~ '
The intent of the head spray feature was to maintain saturated conditiori.
a the RPV head volume by condensing' steam being generated by the hot RPV walls and internals and to decrease thermal stratification in the RPV coolant auring shutdown coolant.
However, operating experience has showr that RPV differential temperature limits can be met as long as the TS al' 9able cool down rate for the reactor coolant is not exceeded while in shutdown cooling, Consequently, head spray was not needed nor was it used.
The RHR head spray mode performed ne safety-related functions.
The 2fety analysis did not take credit for this mode of RHR in mitigating the consequences of an accident or malfunction and it was not required for the 9208140223 920731
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- safe shutdown of the plant.
Because head spray was not required for its intended function nor any safety functions, a design change was made to
- disconnect the head spray line from the RPV head spray nozzle to reduce the
- thermal duty on the RPV.
Additionally, the licensee has stated that approving the proposed changes will reduce radiation exposure to personnel who previously preformed surveillances of these valves.
The two isolation valves, Ell-F022 and Ell-F023, rem ~ain insta' led and continue to perform a primary containment isolation function. The valves are listed in TS Table 3.6.3-1, " Primary Containment Isolation Valves," and are subject to the-associated surveillance requirements. However, *.he valves no longer perform a RCS pressure isolation function.
- The staff has reviewed the licensee's basis for removal of the RPV head spray line from the RPV head spray nozzle.
The RPV head spray performed no safety-related functions and because credit was not taken in the safety analysis for
- mitigation of the consequences of any accident; additionally, removal of this line eliminated a potential leakage pathway from the reactor coolant system.
Lastly, approval of the proposed TS will reduce radiation exposure to plant personnel currently required to perform surveillance of these valves.
Based on the above, the staff finds the licensee's proposed changes to be acceptable.
3.0. 11 ATE CONSULTATION In accordance with the Commission's regulations, the Michigan State official was notified of the proposed issuance of the amendment.
The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
- Th'e amendment changes a requirement with respect to the installation or use of
. a facility component located within the restricted area as defined in 10 CFR Part 20 and changes in. surveillance requirements. The staff has determined that the amendment involves no significant increase in the amnunts, and no significant change in the types, of any effluents which may be released offsite, and that there is no significant-increase in individual or cumulative occupational radiation 3xposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding (57 FR 22261). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth-in 10 CFR Section SI.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 the amendment.
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5.0 CONCLUSION
l 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 pro >osed manner, (2) such activities will be conducted in compliance wit) the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
T. Colburn Date: July 31, 1992 p.
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