ML20195J473
| ML20195J473 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 11/19/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20195J471 | List: |
| References | |
| NUDOCS 9811240303 | |
| Download: ML20195J473 (1) | |
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- tj was a valid demand and a failure of the EDG to respond to that demand since 1990. A revie.y j
of these failure reports indicated that the problems were resolved satisfactorily and did not recur, and that maintenance was completed on line as necessary. The licensee reviewed the surveillance, and maintenance history for the' EDGs and determined that there were no effects on safety and no time-dependent failures which would be affected by extending the frequency of the survelilances. The staff finds the proposed change acceptable.
l 3.6 Batterv Canacity I
Proposed Changes: TS 4.8.3.1c, Electrical Power Systems - D.C. Sources, Batteries. This change revises the requirement for visual inspection, connection verification, resistance i
readings, and battery charger capacity testing from at least once per 18 months to at least once per REFUELING INTERVAL.
j TS 4.8.3.1d, Electrical Power Systems - D.C. Sources, Batteries. This change revises the requirement for' verifying the ability of the battery to supply the actual and/or simulated emergency loads for the design duty cycle when subjected to a battery service test from at least l
once per 18 months during shutdown to at least once per REFUELING INTERVAL dudng j
shutdown.
a TS 4.8.3.1f, Electrical Power Systems - D.C. Sources, Batteries. This change revises the
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requirement to perform the discharge tests of any battery that shows signs of degradation or has reached 85 percent of the service life expected for the application from at least once per 18 months during shutdown to at least once per REFUELING INTERVAL during shutdown.
j TS Bases 3/4.8.1,3/4.8.2,3/4.8.3, Electrical Power Systems - A.C. Sources, D.C. Sources, and i
Onsite Power Distribution. This change revises the Bases to add the exception to the 18-month l
battery service test recommendation provided by Regulatory Guide (RG) 1.129.
Justification for the Changes: The vital D.C. power sources and associated distribution systems help ensure that sufficient instrumentation and control capability is available for monitoring and maintaining the plant status when A.C. power is lost. Each DCPP unit has thres 60 cell,125V vital batteries and five full capacity battery chargers. The three 125V vital busses has a dedicated battery and charger, supplied from its associated 480V vital bus, with the capability of being supplied by an altemate charger supplied from another 480V vital bus. The battery chargers supply the total load requirements of the D.C. system as well as maintaining a constant floating charge on the batteries. The recommendations of RG 1.129 states,"The battery service test should be performed during refueling operations or at some other outage, with intervals between tests not to exceed 18 months." DCPP is also committed to the 1980 version of IEEE-450, which does not make any recommendation for service test frequency, but j
does state that performance test should be performed at five year intervals until the battery is at 85 percent of its service life or shows signs of degradation. IEEE-450-1980, also states that quarterly visual inspections should be augmented with yearly detailed visual inspections. Many battery tests may be performed during power operations, however testing the battery capacity requires discharging the battery. Therefore, performance and capacity surveillances are
. performed with the plant shutdown. The batteries and chargers are tested on a refueling j
9911240303 981119 PDR ADOCK 05000275 P
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