ML20248A978
| ML20248A978 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/27/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20248A969 | List: |
| References | |
| NUDOCS 9806010123 | |
| Download: ML20248A978 (3) | |
Text
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p UNITED STATES NUCLEAR REGULATORY COMMISSION U
'E WASHINGTON, D.C. 30666 4 001
/
- SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION i
RELATEDTO AMENDMENT NOS.214 AND 91 TO FACILITY OPERATING I
LICENSE NOS. DPR-66 AND NPF-73 l
DUQUESNE LIGHT COMPANY OHIO EDISON COMPANY PENNSYLVANIA POWER COMPANY IFE CLEVELAND ELECTRIC ILLUMINATING COMPANY THE TOLEDO EDISON COMPANY BEAVER 1' ALLEY POWER STATION. UNIT NOS.1 AND 2 1
DOCKET NOS. 50-334 AND 50-412
1.0 INTRODUCTION
By letter dated March 17,1998, as supplemented May 14,1998, the Duquesne Light Company (the licensee) submitted a request for changes to the Beaver Valley Power Station, Unit Nos.1 and 2 (BVPS-1 and BVPS-2) Technical Specifications (TSs). The requested changes would revise Action 34 of TS Table 3.3-3, " Engineered Safety Feature Actuation System Instrumentation.' Action 34 is applicable to Functional Units 6.b.," Grid Degraded Voltage (4.16 kV Bus)," and 6.c., " Grid Degraded Voltage (480 v Bus)." The proposed revision to Action 34 would rsquire that with one degraded grid voltage monitoring channelinoperable, the inoperable channel be placed in the tripped condition within one hour; otherwise, the applicable action statement (s) for the associated emergency diesel generator (EDG) made inoperable by the degraded voltage start instrumentation be immediately entered. The proposed revision Action 34 would also require that with two degraded grid voltage monitoring channels inoperable, within one hour at least one of the channels be restored to operable status and the other channel be placed in the tripped condition; otherwise, the associated EDG would be declared inoperable and its applicable action statement (s) entered. Corresponding changes would also be madr. in the bases for TS 3/4.3.2 and BVPS-2 TS Index page x. The May 14,1998, letter provided minor editorial changes to the TS pages that did not change the initial proposed no significant hazards consideration determination or expand the amendment request beyond the scope of the April 22, 1998, FederalRegister notice.
2.0 EVALUATION l
The 4160-volt emergency Nses (and their associated emergency loads) are each protected from 1
degraded voltage conditions by two undervoltage relays per bus, items 6.b. and 6.c. of TS Table 3.3-3 require that the minimum channels operable is two per bus. The undervoltage relays are connected in series to provide a 2-out-of-2 logic. The undervoltage relays actuate to disconnect the emergency buses from their normal supply if the bus voltage decreases below 9806010123 980527 PDR ADOCK 05000334 P
2-90% of the nominal bus voltage. The 2-out-of-2 logic is provided to preclude inadvertent disconnection of the buses from their normal supply. The undervoltage relays are also provided with time delays to prevent unnecessary actuations in the event of short duration voltage.
transients.- Upon actuation of these undervoltage relays, loads are shed from the emergency bus and the associated EDG is started. When the EDG achieves rated voltage and frequency, the EDG output breaker closes and the emergency loads are loaded on it by the load sequencer.
The EDG then provides electrical power to the emergency loads.
The 480-volt emergency b :ses are provided with degraded voltage protection logic similar to that provided for the 4160-volt emergency buses.
Action 34 of TS Table 3.3-3 is provided to specify the actions to be taken in the event one of these undervoltage relays is inoperable. Currently, Action 34 (which was revised by License Amendment Nos.181 (BVPS-1) and 61 (BVPS-2) issued on August 8,1994) states that with the number of OPERABLE channels one less than the total number of channels (2 per bus),
STARTUP and/or POWER OPERATION may proceed provided the following conditions are satisfied: a. The inoperable channel is placed in the tripped condition within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and b. The Minimum Channels OPERABLE requirement is met; however, the inoperable channel may be bypassed for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for surveillance testing of other channels per TS 4.3.2.1.1. However, the current version of Action 34 !s inappropriate for items 6.b. and 6.c. of TS Table 3.3-3 since as noted above, there are only two channels per bus and therefore with one inoperable channel, the Minimum Channels OPERABLE requirement of two channels cannot be met. Therefore, the licensee proposed to modify Action 34 to read as follows:
{
a.
With the number of OPERABLE channels one less than the Minimum Number of 1
Channels, place the inoperable channel in the tripped condition within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, ctherwise, immediately enter the applicable ACTION statement (s) for the associated 3
Emergency Diesel Generator made inoperable by the degraded voltage start instrumentation.
I b.
With the number of OPERABLE channels two less than the Minimum Number of Channels, restore at least one of the two channels to OPERABLE status and place the other in the tripped condition within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; otherwise, immediately enter the applicable ACTION statement (s) for the associated Emergency Diesel Generator made inoperable by the degraded voltage start instrumentation.
The proposed revision to part a. of Action 34 requires that with one channelinoperable, the 1
inoperable channel be placed in the tripped condition within one hour. Placing the one inoperable channel in the tripped condition completes one half of the 2-out-of-2 logic and the trip function could then be completed if the remaining operable channel detected a degraded grid voltage condition. Since part of the function of the degraded grid voltage instrumentation and logic is to automatically initiate separation of the offsite power sources from the emergency buses (which results in an automatic restart of the associated EDG) it is necessary to consider J
the associated EDG inoperable if this automatic separation feature cannot perform its intended j
function. Therefore, it is also necessary to enter the applicable action statements (s) for the associated EDG if the inoperable channel is not placed in the tripped condition.
O d The proposed revision tc part b. of Action 34 requires that with two channels inoperable, at least one channel be restored to operable status and the other channel be placed in the tripped condition within one hour. This is necessary to prevent a loss of function. Upen restoring one channel to operable status and placing the second channel in the tripped condition, the situation reverts to that described in part a. of Action 34. Otherwise it is again appropriate to enter the applicable action statemant(s) for the associated EDG.
The proposed revisions to Action 34 are consistent with current NRC staff guidance for actions to be taken for inoperable grid voltage monitoring channels in similar 2-out-of-2 logic arrangements as reflected in the NRC's improved Standard Technical Specifications for Westinghouse Plants (NUREG-1431, Revision 1). Therefore, the proposed revisions to Action 34 are acceptable.
The proposed revision to the bases for TS 3/4.3.2 provides additional clarification on the connection between the failure of the degraded grid voltage protection system and the resultant inoperability of the affected EDG. Therefore, the NRC staff offers no objection to the proposed bases change.
The proposed revision to the BVPS-2 TS Index page x is editorialin nature only and is therefore acceptable.
3.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Pennsylvania State official was notified of the proposed issuance of the amendments. The State official had no comments.
4.0 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. 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 maybe 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 (63 FR 19969). 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 heath and safety of the public.
Principal Contributor: D. Brinkman Date: May 27, 1998