ML20059J774
| ML20059J774 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 09/12/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20059J764 | List: |
| References | |
| NUDOCS 9009200169 | |
| Download: ML20059J774 (3) | |
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATTON RELATED TO AMEN 0 MENT NO. 45 TO FACILITY OPERATING LICEN5E,No. DPR-21 NORT,JjEAST ffdCLEA9_ ENERGY COMPANY MILLS 10NF taCLEAR POWER STATI0A. UNIT NO. 1 DOCKET WO.,50-245 l
INTRODUCTION By letter dated June 18, 1990, Northeast Nuclear Energy Company (the licensee) submitted a request to change the Millstone Nuclear Power Station, Unit No. 1,
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Technical Specifications (TS).- The request would add operability and
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surveillance requirements for the 14A to 140 tie breaker to TS Section 3/4.5.C.
This TS change was requested in conjunction with plant modifications made as the result of a gas turbine generator (GTG) load study performed by-the licensee.
BACKGROUND The licensee has been working on a TL improvement program.
A review of the TS survalliance requirements for the GTG wac initiated to determine the basis for the statements "equilibeium Londit kaso and " full load" 11 the TS.
The licensee determined that the curret.1 surveillance test, viich required the GTG to be tested at loads above 6 M, was le.s then the statei loads of 9.9 MWe for the GTG in the Updated Final Safety Analysis Report (Ul'SAR).
In addition, on May 11, 1990, the licensee determined that the calculatt d load requirements L
for the GTG was 11.463 MWe rather than the 9.9 MWe stated in the UFSAR.
The licensee's load calculations were verified by General Electric.
This finding was documented by the NRC in Inspection Report 50'245/90-0!,, dated May 11, 1990, and by the licensee in LER 90-007, dated June 11, 1900.
The Feedwater Coolant Injection System (FWCI), which is powered by.the GTG in the event of a loss of Normal Power, requires 6 to 7 We to provide a flow of 8000 gpm.
Because FWCI is a single trtin system and because of sin (le-failure criteria, no credit is taken for the FWCI in the UFSAR accident analyses.
In order tt maintain' operability of the GTG, the licensee declared the FWCI inopertole, thus lowering the required ioads on the GTG to within the capacity of the GTG.
The TS Limiting Condition for Operation (LCO) for an inoperable FWCI is seven days.
On May 18, 1990, the licensee requested a Temporary Waiver of Compliance (TWC) to permit reactor operat,on for up to an additional three days with the FWCI inoperable to allow sufficient time to thoroughly evaluate and implement asdifications to the FWCI and GTG.
In a teleconference on May 18, 1990, the h0 bob f
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J 2-NRC granted the TWC and requested the licensee to commit to several actions 1
concerning surveillance testing of the proposed modifications and to provide a TS amendment for the requested surveillance testing.
A written confirmation of the TWC was issued by the NRC on May 21, 1990. On May 21, 1990, the I
licensee satisfactorily completed testing of the modifications to the GTG and j
j FWCI systems and exited from the TS LCO. -In a letter dated May 21, 1990, the licensee committed to the requests made in the May 18th teleconference and in a letter dated June 18, 1990, requested a TS change to. formalize the new operability and surveillance testing requirements.
r In its June 18th letter, the licensee stated that the setpoint for switching l
the Feedwater Control System from level control, the normal configuration, to i
flow control with one feedwater pump running was decreased from 9600 gpm to approximately 4000 gpm (minimum).
The licensee also stated that a modification was made to trip the feedwater (FW) pump on GTG high exhaust temperature, to prevent the GTG from tripping in the event of a FW line break I
upstrcam of the flow measuring device.'
In addition, the licensee made changes to enhance the load and performance characteristics of the GTG.
Procedure i
changes made necessary by the modifications were completed by the licensee on i
May 25, 1990.
The reduction in the FW single pump flow control,setpoint was made to assure that the maximum load in the GTG will not be exceeded.
This setpoint change will reduce the maximum GTG loading to below its load capacity and will Gill assure adequate FWCI flow in accordance with plant accident analyses.
The GTG high-exhaust temperature trip was added to trip the 14A to 14G bus tie breaker and, thus, remove the FW pump load.from the GTG.
This logic change assures that the GTG will not overload in a FW pump runout condition and preserves the i
GTG as an emergency power source for other ECCS system loads.
The licensee performed other modifications to the GTG to enhance its load capacity.. The l
actual amount of capacity increase is still being evaluated, y
l These modifications were discussed with the staff during' teleconferences i
leading up to the May 18, 1990, TWC ana in a May 25, 1990, Enforcement.
Conference.
The modifications were performed by the licensee under the provisions of 10 CFR 50.59, which permits licensees to make changes to a plant without prior Commission approval unless those changesLinvolve a change to the TS or involves :n unrev'ewed safety question.
This TS change -is being proposed by the licensee as an additional limitation not currently Incorporated in the TS and was proposed at the request of the NRC staff at the time the TWC was granted.
EVALUATION The staff has reviewed the proposed TS changes involving additional requirements for the FWCI and concludes that they are appropriate to assure the operability of FWCI and the GTG in-the event of an accident. The staff finds the proposed changes, additional limitations not presently in the TS,.to e
i be acceptable.
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j ENVIRONMENTAL CONSIDERATION i
This amendment changes a. requirement with respect to the installation or ust l
of a facility component located within the restricted area as defined in 10 i
l CFR Part 20 and changes surveillance requirement We have determined that l
the amendment involves no significant increase in the amounts, and no
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l significant change in the types, of any effluents that may be released offsit,$,
and that there is no significant increase in individual or cumulative.
i j-occupational radiation exposure.
The staff has previously published a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding.
Accordingly, the amendment l
meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section 51.22(c)(9).
Pursuant to 10 CFR Section 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection,
with the issuance of the amendment.
CONCLUSION t
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 7
be conducted in compliance with the Commission's regulations, and (0)'the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
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Dated:
September 12, 1990 Principal Contributor:
M. Boyle l
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