ML20114B636
| ML20114B636 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 08/25/1992 |
| From: | Frieling G WISCONSIN ELECTRIC POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20114B639 | List: |
| References | |
| CON-NRC-92-098, CON-NRC-92-98 VPNPD-92-292, NUDOCS 9208310020 | |
| Download: ML20114B636 (3) | |
Text
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Wisconsin Electnc PG vER COMPANY a w Mogavo ca m W%ee M woi
("W22i N VPNPD-92-292 NRC-92-098 August 25, 1992 U.
S.
NUCLEAR REGULATORY COMMISSION Document Control Desk Mail Station P1-137 Washington, D.
C.
20555 Gentlemen:
DOCKETS 50-266 AND 50_-301 REVISION TO TECHNICAL SPECIFICATION CHANGE REOUEST 132 LIMITING CONDITIONS FOR OPEPATION POWrR DISTRIBUTION ON SAFEGUARDS BUSES POIN'. BEACH NUCLEAR PLANT, UNITS 1 AND 2 On Sep ember 22, 1989, Wisconsin Electric (Licensee) requested amendmeits t? Fac iity Operating Licenses DPR-24 and DPR-27 for
~
Point beach Nut laar Plant, Units 1 and 2, respectively, to incorporate chang.s to Technical Specification Section 15.3.7,
" Auxiliary Electrical Systems."
The requested changes establish Limiting Conditions for Operation (LCO's) for safeguards auses in the Point Beach Nuclear Plant electrical distribution system.
The changes proposed in our September 22, 1989, request will add new LCO's limiting the amount of time that 480 volt safeguards buses B03 and B04 or 4160 volt safeguards buses A05 and A06 could be tied together via a common tie-breaker.
If the time allswed by the LCO cannot be met, any operating unit would be required to be pieced in hot shutdown within six hours and cold shutdown within the following thirty hours.
It was also our intent to allow the use of a safeguards bus tie-breaker only when the associated unit is in a cold shatdown or refueling shutdown condition.
This letter summarizes proposed revisions to our originally requested changes to clarify the on-site electrical distribution j
system configuration including the 4160 and 480 volt safeguards buses during power and shutdown operations.
We have also provided DO a discussion in the basas delineating the purpose and application LO for the proposed specifications.
Technical Specification pages with our revised proposed changes are attached.
f Our proposed changes will revise Specifications A.1 and A.2 in Section 15.3.7 related to the 4160 volt buses to separate the operability requirements for 4160 volt buses A03 and A04, which are f
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NRC Document Control Desk August 25, 1992 page 2 j
not safety-related, and the A05 and A06 buses, which are safety-i related.
An independent lineup of safeguards buses A05, A06, B03 and B04 will be required for startup and operation under normal and abnormal circumstances.
This revision will require, during unit 4
startup and power operation, that the safeguards bus tie-breakers i
in both units be removed from service.
The tie-breakers for the l
A05 and A06 buses will be required to be removed from the breaker cubicles.
The tie-breakers for the B03 and PO4 buses will be reg': ' red tn be open with control power removed.
Removing the A05 a
and A06 tie-breakers from the breaker cubicles and removing the j
control power from the B03 and B04 tie-breakers will be done to i
resolve previously identified single failure concerns.
These i
concerns include failure of the tie-breaker to trip following a loss of power prior to the buses' oading on a diesel generator.
These proposed technical specification requirements are currently j
administratively implemented by Point Beach Huclear Plat.t i
procedures, i
In order t facilitate switching and safeguarls bus as well as service transformer inspection and maintenance, cur proposed changes will revise Specification B.1 to c)1ow one pair of buses, A05 and A06 or B03 and B-04, for a unit in cold or refueling shutdown to be tied together for up to eight hours.
This constitutes a temporary relaxation of the single failure criteria.
l Some inspection and maintenance activities will likely take longer than eight hours.
Therefore, our proposed revision will permit one pair of buses, A05 and A06 or B03 and B04, for a defueled unit to be tied together through their common tie-breaker in excess of i
eight hours.
In the defueled condition the eight-hour period will only be allowed to be exceeded if an evaluation is performed to i
show that the loads that remain, or can be energized by the buses,-
will net cause a potential overload of the associated diesel generator and the applicable Limiting Conditions for Operation of the equipment removed from service are entered for the operating unit.
i This change request will also add the requirement that spent fuel pool cooling can be maintained by a single train of the cooling system when a unit is fully defueled and a tie-breaker is in use.
With a full core off load, the heat load ca the spent fuel cooling system is the highest.
By ensuring that one train of spent fuel i
pool cooling is adequate, the effects of a loss of a spent fuel pump caused by single failure of a tie-breaker and loss of a bus are minimized.
An alternate means for providing makeup to the spent fuel pool on a loss of spent fuel pool cooling is discussed in the PBNP Final Safety Analysis Report Section 9.3,
" Auxiliary Coolant System."
Lastly, a proposed addition has been made to the diesel generator i
LCO in Specification B.1.
This addition establishes the requirement that a diesel generator is not to be removed from j
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NRC Document Control Desk August 25, 1992 Page 3 service during the time that a safeguards bus tie-breaker is in use.
This will ensure that the redundancy of-safeguard bus power supplies is maintained to the largest extent pra:ticable with the electrical distribution system for safeguards equipment in this configuration.
We have reviewed these revised changes against our evaluation and no significant hazards determination contained in sur September 22, 1989, submittal.
The changes proposed in our September 22, 1989, request, as revis.d by this letter, constitute additional restrictions and limitations on the operation of Point Beach Nuclear Plant not previously contained in the Technical Specifications.
The revised changes summarized in this letter maintain the intent of our original submittal.
The evaluation of acceptability and determination of no significant hazards contained in our September 22, 1989, submittal continue to apply to this ravision to our original submittal.
We have discussed these revisions with Mr. Robert Samworth, NRR Project Manager for Point Beach Nuclear Plant, and Dr. Saba Saba of your staff.
If you have any additional questions or require additional information, plesse contact us.
Sincerely
/'
/
ZP O
j G.
D.
Frieling, Manager Nuclear Engineering Attachments Suoscribee md sworn to before ne this 2d day of /ht n f
- 1992, s
va
/
MC Notary Public, State of Wisconsir.
My Commission expires 6-2 2 - 9 '/.
Copies to NRC Regional Administrator, Region III NRC Resident Inspector L.
L.
Smith, PSCW