ML20113C454
| ML20113C454 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 06/27/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20113C450 | List: |
| References | |
| NUDOCS 9607010244 | |
| Download: ML20113C454 (4) | |
Text
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i UNITED STATES y
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NUCLEAR REGULATORY COMMISSION 5
'f WASHINGTON, D.C. 30e06 0001
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IAEETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGUt.ATION RELATED TO AMENDMENT NOS. 183 AND 164 TO FACILITY OPERATING LICENSE NOS. DPR-70 AND DPR-75 PUBLIC SERVICE ELECTRIC & GAS COMPANY PHILADELPHIA ELECTRIC COMPANY DELMARVA POWER AND LIGHT COMPANY ATLANTIC CITY ELECTRIC COMPANY SALEM NUCLEAR GENERATING STATION. UNIT NOS. 1 AND 2 DOCKET NOS. 50-272 AND 50-311
1.0 INTRODUCTION
By letter dated February 6,1996, Public Service Electric & Gas Company (PSE&G) requested that Facility Operating Licenses DPR-70 and DPR-75 be 4
l, amended to modify the Technical Specifications (TS) for Salem Nuclear Generating Station (SNGS), Units 1 and 2.
The proposed change will lower the 125V battery charger surveillance amperage from 200 amps to 170 amps while battery chargers are being replaced during the current shutdown of both units.
In response to a request for additional information during subsequent telephone conversations, PSE&G submitted battery charger sizing and de component voltage drop calculations to NRC.
2.0 EVALUATION PSE&G is upgrading plant equipment in SNGS, Units 1 and 2.
As part of this upgrade,125V battery chargers will be replaced during the current shutdown of both units. As a result of the unavailability of spare parts for the existing battery chargers, new chargers have been ordered as replacements.
These new chargers are similar to the 125V battery chargers at the Hope Creek station and will improve spare parts availability for all three units in the future.
'i The new chargers have a different power factor than the existing units and, as a result, require higher in existing battery chargers. put current for the same output current than the Input current to the battery chargers is calculated to exceed the ampacity of the existing ac cables if the charger output current is maintained at a level of at least 200 amps as required in the existing TS. To avoid the replacement of the existing cables (to support a 200-amp TS surveillance requirement) PSE&G proposes to lower the output current requirement to at least 170 amps.
4 9607010244 960627 PDR ADOCK 05000272 f-PDR e
3.0 EVALUATION PSE&G proposes to revise TS surveillance requirement 4.8.2.3.2.e, which-states:
"At least once per 18 months by verifying that:
- 1. The battery charger will supply at least 200 amperes at 125 volts for at least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />."
"At least 2DQ amperes" will be changed to "At least 129 amperes."
PSE&G performed and submitted calculations to support battery charger loading that includes a worst-case loading of 161 amps.
In the worst-case battery charger loading condition, the charger will restore the battery from the design minimum charge to the fully charged state while supplying normal steady-state loads as specified in Institute of Electrical :.nd Electronics Engineers (IEEE) Standard 308-1971, " Criteria for Class IE Electric Systems for Nuclear Power Generating Stations." This worst-case loading of 161 amps is less than the minimum 170 amperes PSE&G proposes for the TS. At the proposed TS value, replacement of battery charger supply cabling would not be needed because the existing cable will have enough ampacity rating to carry the ac input current.
PSE&G also submitted calculations that substantiate the capability of the charger to restore the battery from the design minimum charge to the fully charged state while supplying normal steady-state loads following LOOP /LOCA and station blackout events. However, the charging time to restore the battery from design minimum charge to a fully charged state will increase from 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> to 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
Based on additional information submitted in response to the phone calls (available in the Public Document Room (PDR) under Accession Number 9605280229), the following concerns were resolved:
1.
In response to the question as to what was the worst-case loading of the battery charger in the previous revision of the calculation, PSE&G stated that the previous charger calculation was based on actual loading data on the charger collected by field measurement during a 2-month period when units were at 100 percent power. Out of 20 measurements performed during this period, the worst case loading was seen in the Channel-A battery charger and the measured reading was 101 amps.
2.
IEEE Standard 946-1992 provides two equations to use for charger sizing.
One equation deals with the continuous load and ampere requirements to charge the battery, and the second equation deals with the contribution of continuous and non-continuous loads. The charger rating will be the larger of two equation values.
In response to the question as to why PSE&G did not use the second method, PSE&G stated that the noncontinuous loads were not considered because they are not connected directly to the de bus.
For example, communication system power supplies and fire protection systems are connected to inverters for which ac power is the primary source.
- 3.
In response to the question as to how the recharging time of the battery, which will increase from 20 to 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />, will meet the Westinghouse Standard TS requirement of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, PSE&G stated that it is not committed to the "24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />" in the TS but follows IEEE Standard 308-1971, which did not specifically mention any hours other than the " time stated in design basis." After further investigation, the staff found no basis for the specific "24-hour" requirement.
Also as a result of the phone calls, a note was added to the conclusion of the battery charger sizing calculation that states the battery charger sizing and voltage drop considerations must be evaluated before any new load is added to the 125V de system.
(The procedure page with this added note was provided to the NRC by telefax to Len Olshan dated May 29, 1996, and is available in the PDR under Accession Number 9606040033.)
The proposed amendment will change the required amperage for battery charger TS surveillance 4.8.2.3.2.e from "at least 200 amperes" to "at least 170 amperes." PSE&G is replacing Salem, Units 1 and 2 battery chargers with a similar type of battery charger that it has used in the Hope Creek Station.
Consequently, spare parts availability will be improved for all three units.
Input current to the new battery chargers is calculated to exceed the ampacity rating of the existing input ac cables if the charger output current is maintained at a level of at least 200 amps as required in the existing TS.
PSE&G is proposing to reduce the output current to at least 170 amps.
PSE&G's calculation shows a worst-case battery charger loading condition of 161 amps in which the charger restores the battery from the design minimum charge to the fully charged state while supplying normal steady-state loads. This worst-case loading condition is covered by the proposed TS level of at least 170 amps. The charger output current of 170 amps will extend the recharging time of the battery from 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> to 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />, which is acceptable since the licensee is not committed to any specific time limit by the TS. The proposed amendment will not significantly increase the probability or consequences of an accident previously evaluated. The staff finds the change acceptable.
4.0 STATE CONSVLTATION In accordance with the Commission's regulations, the New Jersey State official was notified of the proposed issuance of the amendments. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements. The NRC staff has determined that the amendments involve 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 Commission has previously issued a
[
> proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (61 FR 7556). Accordingly, the amendments meet 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 the amendments.
5.0 CONCLUSION
The Commission 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 proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
S. K. Mitra Date:
June 27. 1996 l