ML20044D064
| ML20044D064 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 03/26/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20044D055 | List: |
| References | |
| NUDOCS 9305170185 | |
| Download: ML20044D064 (4) | |
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UNITED STATES jk_yl'ij NUCLEAR REGULATORY COMMISS!ON l
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gv SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 137 AND 141 TO f
FACILITY OPERATING LICENSE NOS. DPR-24 AND DPR-27 i
WISCONSIN ELECTRIC POWER COMPANY POINT BEACH NUCLEAR PLANT. UNIT NOS. 1 AND 2 f
DOCKET NOS. 50-266 AND 50-301
1.0 INTRODUCTION
l A request for a temporary NRR Waiver of Compliance from the conditions in Technical Specification Table 15.3.5-3, " Emergency Cooling," Item 4.a.
" Degraded Voltage (4.16 kV)," was granted to Wisconsin Electric Power Company l
on January 14, 1993.
It allowed the continued operation of the Point Beach Nuclear Plant, Units 1 and 2 with non-conservative degraded voltage relay setp9ts fer a number of the safety buses. The staff granted the Temporary Waiver of Compliance based on conservative licensee compensatory actions and an understanding that it would not be in the interest of public health and safety to start and operate both emargency diesel generators continuously as the Technical Specifications would require. The NRC confirmed the granting of a temporary waiver of compliance in a letter to WEPCo dated January 14, 1993.
This waiver was also based, in part, on the licensee's expressed intent to submit an application for an amendment to the degraded voltage setpoint i
specification.
t By letter dated January 19, 1993 Wisconsin Electric Power Company requested a i
revision to the Technical Specifications on an exigent basis to change the degraded voltage relay setpoints and the corresponding action statement.
l Title 10 of the Code of Federal Regulations, Part 50.91, stipulates in section (a)(6) that, where the Commission finds that exigent circumstances exist in that a licensee and the Commission must act quickly and that time does not permit the Commission to publish a Federal Reoister notice allowing 30 days i
for public comment, and it also determines that the amendment involves no i
significant hazards considerations, it will, among others, either issue a Federal Reoister notice providing an opportunity for hearing and allowing at 1
least two weeks for prior public comment or use the local media to provide reasonable notice to the public in the area surrounding a licensee's facility.
l The 5.taff concluded, however, that a 30-day Federal Reaister notice period was appropriate to allow sufficient opportunity for prior public comment on the proposed permanent Technical Specification change request sir.ce the licensee i
was granted relief from Technical Specification 15.3.5-3, Item 4.a in the letter dated Jcnuary 14, 1993, granting the Temporary Waiver of Compliance removing the actual exigent nature of the situation. Therefore, the staff denied the licensee's request for handling the license amendment in an exigent manner.
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. Specifically, the proposed amendment would revise Technical Specification l
Table 15.3.5-1, " Engineered Safety Features Initiation Instrument Setting Limits," Item 9, " Degraded Voltage (4.16 KV)."
Item 9 now requires the degraded voltage relay setpoints to be set at greater than or equal to 3875 volts plus or minus 2%. The proposed amendment would change this setpoint to 3959 volts plus or minus 1/2%.
The proposed amendment would also revise Technical Specification Table 15.3.5-3, " Emergency Cooling," Item 4.a. " Degraded Voltage (4.16KV)," and Item 4.b, " Loss of Voltage (4.16 KV)."
Item 4.a specifies the number of instrument channels which must be operable for degraded voltage protection for each 4.16 KV safeguards bus and the degree of redundancy which must exist.
Item 4.b imposes similar requirements for the loss-of-voltage protection channels.
If these conditions cannot be met, the current specifications permit continued operation for up to 7 days provided both emergency diesel generators are otherwise operable and the associated diesel generator is operating and providing power to the affected bus.
If the condition is corrected within 7 days, then the affected unit is required to be placed in hot shutdown. The proposed amendment would change the action statement to both items to read:
" Declare the associated emergency diesel generator inoperable for the affected bus. The applicable Limiting Condition for Operation (LCO) shall be entered.
Separate !C0s may be entered for the Degraded Voltage and Loss of Voltage functions."
In addition, the amendment would add the bus designations in Technical Specification Tables 15.3.5-1, and 15.3.5-3.
2.0 EVALUATION Eased en the analysis performed by ABB Impe11 Calculation 0970-150-007, Revision 0, Wisconsin Electric Power Company has determined that the existing settings for the degraded voltage relays installed on the 4160 V safety-related buses may be too low to provide adequate protection for all safety-related equipment. An undervoltage relay setting of greatu than or equal to 3959 V +/- 0.5 % is necessary to protect equipment while still providing an adequate level of equipment reliability. The new, higher setpoint for the degraded voltage relays will allow the removal of offsite power and allow the transfer of the affected safety-related buses to the emergency diesel generators at an appropriate voltage level to protect safety equipment. This value for the degraded voltage relay setting is based on the worst case assumptions for the safety grade bus loading and system configuration and assures the protection of safeguard equipment from degraded voltage conditions.
The licensee states that the field measurements and verification will be performed during 1993 to verify and refine the existing calculation inputs assumptions, and results. These meamrements will include quantifying actual relay, calibration, and potential transformer tolerances. Because of the equipment involved, portions of this verification effort will be required to be performed during the 1993 maintenance and refueling outages for both units and is expected to be completed by the end of the Unit 2 refueling outage in
November 1993.
Following completion of this verification effort, additional acticn, if needed, will be taken to insure this relay setting continues to provide the appropriate level of equipment protection as well as the reliability of offsite power to the safety grade buses.
The licensee further states that its planned actions and schedule will be provided to the NRC at that time. The staff has evaluated the licensee's submittal and has determined that the licensee has provided justification for the change in the degraded voltage relay setpoints in Technical Specification Table 15.3.5-1 and, therefore, this change is acceptable.
The licensee has also proposed a change to the actions required if the conditions specified in Technical Specification Table 15.3.5-3, Items 4.a and 4.b, are not met. Technical Specification Table 15.3.5-3, Item 4.a. specifies that two of the three existing channels of degraded voltage protection for each 4.16 kV safeguard bus be operable and a minimum degree of redundancy of one channel per bus be maintained.
If these conditions cannot be met, the specification permits continued operation for up to 7 days provided both emergency diesel generators are otherwise operable and the associated diesel generator is operating and providing power to the affected bus.
If the condition is not corrected within 7 days, then the affected unit is required to be placed in hot shutdown. The same actions are required if the conditions of Item 4.b, " Loss of Voltage (4.16 kV)," are not met.
The licensee has determined that operation for an extended period of time with all four of the safety-related 4160 V buses supplied from the emergency diesel generators was not consistent with maintaining the minimum level of plant safety.
With the proposed change, the associated emergency diesel generator is administrative 1y declared inop rable for the affected bus only. The LCO is entered with respect to the affected unit only. This is appropriate since the emergency diesel generators are shared between the two units.
Inoperable degraded voltage or loss of voltage protection on a bus in one unit does not prevent the emergency diesel generator from performing its intended function with respect to a loss of voltage or degraded voltage condition on the unaffected unit's bus or from responding properly to an actuation of the unaffected protective function on the affected bus. The LCOs for inoperable degraded voltage and inoperable loss of voltage-channels may be entered separately.
It is unlikely that both protective functions would be inoperable concurrently.
The licensee states that channel check, calibration, and test frequencies specified in Table 15.4.1-1," Minimum frequencies for Checks, Calibrations and Test of Instrument Channels," ensure that an inoperable channel is promptly i
detected and returned to service. This LCO, the required actions, and the i
supporting surveillance are consistent with the }! STS and are, therefore, acceptable.
In addition, the licensee has made editorial changes to Technical Specification Table 15.3.5-1, Items 9 and 10, and Technical Specification Table 15.3.5-3, Items 4.a, b, and c.
These changes add the bus designations i
for the 4.16 kV and 480 Y buses, as appropriate, to the bus. The staff finds this proposed change to be acceptable.
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3.0 STATE CONSULTATION
t In accordance with the Commission's regulations, the Wisconsin State official l
was notified of the proposed issuance of the amendments. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
These amendments involve a change in the installation or use of a facility I
component located within the restricted area as defined in 10 CFR Part 20 or change an inspection or surveillance requirement. 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 i
occupational radiation exposure. The Commission has previously published a proposed finding that these amendments involve no significant hazards consideration and there has been no public comment on such finding.
Accordingly, these amendments meet the eligibility criteria for categorical i
exclusion set forth in 10 CFR 651.22(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 these amendments.
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5.0 CONCLUSION
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The staff 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 j
security or to the health and safety of the public.
Principal Contributor:
N.K. Trehan Date: March 26, 1993 i
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