ML20206R807
| ML20206R807 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 01/13/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20206R804 | List: |
| References | |
| NUDOCS 9901200264 | |
| Download: ML20206R807 (3) | |
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UNITED STATES g
j NUCLEAR REGULATORY COMMISSION
- %..... /g WASHINGTON, D.C. 30806 00tH SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.198 TO FACILITY OPERATING LICENSE NO. NPF-6 ENTERGY OPERATIONS. INC.
ARKANSAS NUCLEAR ONE. UNIT NO. 2 DOCKET NO. 50-368
1.0 INTRODUCTION
By letter dated June 29,1998 (2CAN069807), Entergy Operations, Inc. (the licensee) submitted a request for changes to the Arkansas Nuclear One, Unit No. 2 (ANO-2) Technical Specifications (TSs). The requested changes would revise TS surveillance requirements SR 4.8.2.3.b2, SR 4.8.2.3.c.4 and the Bases for TS 3.8.2.3 Action "b" to allow the modification of ANO-2120 volt vital alternating current (ac) electrical distribution system by installing new inverters during the coming refueling outage (2R13).
2.0 EVALUATION J
2.1 TS Surveillance Reauirement 4.8.2.3.b.2 - Batterv Terminal Corrosion The existing ANO-2 TS battery inspection SR 4.8.2.3.b.2 provides the necessary surveillance to detect conditions that can cause power losses due to corrosion at the terminals or connectors.
The proposed change will revise SR 4.8.2.3.b.2 to read as follows: "There is no visible corrosion at battery terminals and connectors, or the connection resistance of these items is 4
s150 X 10 ohm." This SR has been modified to allow the determination of the resistance readings on the associated battery connections in addition to the corrosion inspection contained in the original surveillance requirement. This is consistent with similar requirements of NUREG-1432," Standard Technical Specifications for Combustion Engineering Plants." The 4
terminal resistance value of 5150 X10 ohm is based on the values of the present limits in SR 4.8.2.3.c.3. The resistance measurements provide an indication of physical damage or abnormal deterioration of the terminal or connectors that could potentially degrade the performance of the battery. This change is an enhancement to the current TS. This change does not reduce the margin of safety specified in the TSs and does not represent a condition adverse to the health and safety of the public.
2.2 TS Surveillance Heauirement 4.8.2.3.c.4 - Batterv Charaer Canacity The present ANO-2 inverters are powered from their 480 volt normal ac source and automatically shift to direct current (de) power on a loss of the normal ac source. The 125 voit 9901200264 990113 PDR ADOCK 05000368 P
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2-vital de system loads are normally supplied by its associated battery charger, an additional
" swing" battery charger can be placed in service on either of the vital de buses to replace its associated normal battery charger. The licensee is planning to install new inverters which will not contain a rectifier circuit and will be, therefore, normally powered from the 125 volt vital de 1
system. The inverter replacement modification will increase the de system loads which would exceed the capacity of the existing 200 ampere " swing" battery charger. As a result, SR 4.8.2.3.c.4 will be revised to require an increase in the minimum battery charger capacity from
' 200 to 300 amperes.
After the modification, the dc system will consist of one battery charger in service connected to its associated battery for each train and a second charger for each train as a standby. This standby charger on each train will be placed in service manually.
The existing chargers will be replaced with chargers of 400 ampere design capacity. The sizing of the new battery chargers will satisfy the R.G.1.32 requirement as each charger will be able to fumish the energy for the largest combined demands of the loads while restoring the battery capacity from minimal charged state to the fully charged state.
The proposed periodic testing requirement of SR 4.8.2.3.c.4 of 2300 ampere limits ensure that I
the chargers will perform their function. The additional 100 amperes will allow a faster battery recharge time and will allow available capacity for potentialload growth of the de system. This design change will adequately compensate for the inverter replacement and is acceptable. This change does not reduce the margin of safety specified in the TSs and does not represent a condition adverse to the health and safety of the public.
2.3 Bases for TS 3.8.2.3. Action b - Batterv Surveillance Reautrements TS 3.8.2.3 Action "b" provides the required action to be taken in the event that one of the full capacity chargers is inoperable. This action requires the performance of SR 4.8.2.3.a.1 (verify the parameters in Table 4.8-2, BATTERY SURVEILLANCE REQUIREMENTS) within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter. If any Category A limit in Table 4.8-2 is not met while a charger is inoperable, the associated battery bank shall be declared inoperable and ACTION "a" entered. The category A limits in Table 4.8-2 specify the normallimits for electrolyte level, float voltage and specific gravity for each designated pilot ceII. When TS 3.8.2.3 ACTION "b"is entered without the associated battery bank being on float (i.e. charger not connected to the bus), pilot cell float voltage is determined by measuring pilot cell voltags. The term " full capacity charger" as used in TS 3.8.2.3 is defined as a charger that is capable of supplying an l
output of 2 300 amperes." Also Action "b" states that if any category A limits in Table 4.8-2 is not met while the charger is inoperable, the associated battery is inoperable.
Table 4.8-2 (BATTERY SURVEILLANCE REQUIREMENTS) is used to verify the operability of the battery when the battery is on float. The bases for TS 3.8.2.3 Action "b" adds clarification
' when the battery is not on float (charger not connected to the de bus). The staff finds this change acceptable.
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3.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Arkansas State official was notified of the proposed issuance of the amendment. The State official had no comments.
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4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes 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 changes surveillance requirements. The NRC staff has determined that the amendment involves 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 amendment involves no significant hazards consideration, and there has been no public comment on such finding (63 FR 56244). Accordingly, the amendment meets 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 amendment.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, thet: (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 amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: Saba N. Saba Date: January 13, 1999 y
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