ML20125C616
| ML20125C616 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 05/23/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20125C594 | List: |
| References | |
| NUDOCS 8506120097 | |
| Download: ML20125C616 (3) | |
Text
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 82 TO FACILITY LICENSE NO. DPR-71 AND AMENDMENT NO 109 TO FACILITY LICENSE NO DPR-62 CAROLINA POWER A LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 DOCKET NOS. 50-325 AND 50-324 1.0 Introduction By letter dated July 29, 1982, as supplemented August 30,1984 and January 18, 1985, theCarolinaPower&LightCompany(CP&L/thelicensee) submitted proposed changes to the Technical Specifications (TS) appended to Facility Operating License Nos. DPR-71 and DPR-62 for the Brunswick Steam Electric Plant, Units 1 and 2.
The amendments would modify the Technical Specifications to correctly identify certain relays associated with the plant emergency power supplies and provide correct setpoint values for actuating these relays.
2.0 Discussion Following investigation of a reactor scram, the licensee determined Degraded Voltage Surveillance Tests on Unit I were not being performed.
The licensee's review of a previous modification revealed that incorrect relays were referenced in the plant modification and therefore, the incorrect setpoint values were incorporated in the Technical Specifications. Table 3.3.3-2, Item 5.a. describes Balance-of-Plant (BOP)
Busses IC, 10, 2C and 20 for Device 27.
The correct relay should have been Emergency Busses E-1. E-2, E-3 and E-4, Device 27/59E. The proposed changes to the Technical Specifications would correct this error and provide correct setpoint values for actuating the relays.
3.0 Evaluation We have reviewed the licensee's Technical Specification change request for the Brunswick Steam Electric Plant (BSEP), Units 1 and 2.
This revision reflects changes in Tables 3.3.3-1/2 and 4.3.3-1 of the TS.
This change is specifically related to loss of power (loss of voltage / degraded voltage relays)setpoints.
The subject TS change was warranted to correct the discrepancies they discovered in the existing TS following an investigation of the June 28, 1982 reactor scram on BSEP Unit 1.
The licensee found incorrect relays were referenced in the TS which resulted in incorrect setpoint values for the relays. The licensee stated that the present TS refers incorrectly to k $N4 P
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.. the loss of voltage relays (Device 27) on B0P Busses IC, 1D, 2C and 2D instcad of relays (27/59E) on Emergency Busses El, E2, E3 and E4 The correct trip setting for the emergency bus relays (General Electric relay type IAV53K) is 3430 172 volts on a 4.16 kV basis with a trip time of 1.575 seconds at 0 volts.
It is designed to trip the relay below the trip setpoint.
By letter dated August 30, 1984, a revised voltage drop study was submitted.
In this analysis the licensee calculated the minimum bus voltage with the offsite grid at the minimum expected voltage while postulating the maximum plant load. We have reviewed the results of the voltage drop analysis. The results indicate that the distribution system remains above the aforementioned relay setpoint for the minimum grid voltage and the maximum plant load condition.
Further, it demonstrates that the safety related loads will accelerate to full speed in less than the time delay specified in the TS.
Thus, we find that the voltage profile for the BSEP Units 1 and 2 distribution systems will remain above the relay trip curve for the minimum grid voltage.
As for the proposed deletion of daily channel checks (surveillance requirements) for the degraded relays (device 27/DV), the licensee's response dated January 18, 1985 explained that the once per shift channel check performed on these relays consists of a check for relay targets which indicate if the relay is tripped or not and verification that the installed voltmeters on the 4.16 kV bus read greater than 3800 volts. This voltage information is also available (redundant) in the control room. The licensee contends that checking for the relay target position does not provide indication of relay operability.
Furthermore, the relays are arranged in a two-out-of-three logic for reliable actuation to avoid spurious trips.
Based on the above reasons, the licensee concludes that the once per shift (daily) channel check should be deleted. Based on our review and in view of the fact that the licensee has capability to monitor the bus voltages and retains monthly functional testing and channel calibration of the voltage relays every refueling, we concur with the licensee on deletion of daily channel checks for those voltage relays.
Based on the above review, the proposed changes to the Technical Specifications are acceptable.
4.0 Environmental Considerations The amendments involve a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The 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 Comission has previously issued a proposed finding that the amendments involve no significant hazards consideration and there has been no public coment on L
3-such finding. Accordingly, the amendments meet the eli for categorical e.sclusion set forth in 10 CFR 51.22(c)(gibility criteria 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 Conclusions 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 be conducted in compliance with the Commission's regulations and 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:
P. Kang Dated: May 23, 1985 a
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