ML20210T576
| ML20210T576 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 08/29/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20210T573 | List: |
| References | |
| NUDOCS 9709150229 | |
| Download: ML20210T576 (5) | |
Text
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'k UNITED STATES g
j NUCLEAR REGULATORY COMMISSION 1
WASHINGTON D.C. 3046Hool
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.157 TO FACILITY OPERATING LICENSE NO. DPR-72 FLORIDA POWER CORPORATION. ET AL.
CRYSTAL RIVER UNIT NO. 3 NUCLEAR GENERATING PLANT DOCKET NO. 50-302 1.0 BTRODUCTION By letter dated August 4, 1997. Florida Power Corporation (FPC or the licensee), the licensee for the Crystal River Nuclear Generating Unit 3 (CR3) submitted a request to revise the CR3 technical specifications (TS) to extend the frequency for certain sur/eillances related to the emergency diesel generators (EDGs).
Specifically. TS Surveillance Requirements (SR) 3.3.8.1, and SR 3.8.1.3 would be revised to extend the channel Functional test surveillance frequency and the EDG operation, respectively, from 31 days to 60 l
oays. The aroposed TS amendment would be a one time change and applicable i
until Novem]er 23, 1997.
Pursuant to 10 CFR 50.91(a)(6)(vi), the licensee requested the Nuclear Regulatory Commission (NRC) staff to approve its proposed TS change on an exigent basis.
By letter dated August 16, 1997, the licensee modified its August 4,1997 request and withdrew the proposed change to the SR 3.8.1.3.
Accordingly, this safety evaluation addresses only the proposed change to the SF. 3.3.8.1.
The licensee's-August 16, 1997, letter did not-alter the staff's initial proposed no significant hazards consideration determination.
2.0 BACKGROUND
FPC is replacing the radiators of 'A' and "B" EDL at CR3 during the present
-outage as part of an upgrade to the ratings of both EDGs.
This modification is beimo implemented on one EDG at a time, which makes the EDG inoperable.
The performance of this work is scheduled for a minimum of 42 days.
Because CR3 improved TS (ITS) surveillance requirements of 3.3.8.1, Channel Functional Test of EDG Loss of Power Start have a frequency of 31 days, the surveillance will.be required during the replacement time of the radiator.
During the performance of_the surveillances, the EDG would be declared inocerable. The-licensee considers that performing the SRs on one EDG while the other EDG is inocerable would reduce the overall defense in-depth, potentially reducing the safety margins. FPC's request is to change the frequency of the surveillance requirements from the current 31 days to 60 days.
This request is for a one-time temporary change to be effective until November 23. 1997.
After this date the specifications will revert back to the current 31 days frequency.
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2 3.0 EVALUATION 1
For the upgrade of the existing EDGs. the radiators are being replaced during the present outage.
Thus, the EDG is in an out-of-service condition. A minimum of 42 days is needed to complete the replacement which may extend to an estimated 55 days if any one of several contingencies arises. The time to 1
perform the replacement exceeds the TS surveillance interval of 31 days.
The surveillance with one EDG inoperable are possible, however, this is not desirable as both EDG "A" and EDG "B" will be inoperable. With both EDGs inoperable, a loss of the normal power could render the decay heat removal unavailable.
In addition. Surveillance Procedures SP-907A/B. "The Monthly Functional Test of.4160V ES 3.3.8.1 Undervoltage and Degraded Grid Relaying." which are used to perform SR 3.3.8.1 can lead to an increased potential for equipment malfunction or personnel error causing a loss of Decay Heat Removal capability.
In fact, on February 7, 1995, the performance of the surveillance procedure SP-907A on 4160V ES Bus "A" resulted in an inadvertent EDG loss of power start signal and stripping of all loads from the bus.
Presently. CR3 is in a cold shutdown condition and extending the channel functional test from 31 to 60 days on a one time basis is not expected to result in increased risk to the health and safety of the public. Also, given the potential detrimental effects on the heat removal function of performing this test with one EDG inoperable, the staff agrees that it is appropriate to extend the surveillance.
4.0 STATEMENT OF EXIGENT CIRCUMSTANCES The licensee. in its August 4.1997 application. requested that its proposed TS change be approved on an exigent basis.
The Commission's regulation as stated in 10 CFR 50.91, provides special exceptions for the issuance of amendments when the usual 30-day public notice cannot be met.
One type of special exception is an exigency.
An exigency is a case in which the staff and the licensee need to act quickly and time does not permit the Commission to allow 30 days for prior public comment.
The NRC staff must also determine that the amendment request involves no significai;t hazards consideration, and the appropriateness of the conditions which resulted in the need for the exigent request.
Pursuant to 10 CFR 50.91(a)(6)(vi). the licensee provided an explanation of the conditions which resulted in the need for the exigent request and why it could not have been avoided.
The discussion demonstrated the licensee's best efforts to make a timely application after becoming aware of the need for a license amendment.
Currently. CR3 is in Mode 5.
As part of its EDG upgrade program, the licensee originally planned to replace the EDG radiator during its scheduled refuel outage in 1998. The licensee has now determined that a potential exists for the EDGs to exceed the design basis ambient temperature and as a result.
3 decided to implement the radiator replacement during the current outage. As the modification was finalized, the licensee discovered that the effort involved more extensive fabrication than originally anticipated.
FPC considered alternatives to resolve the problem of the radiator replacement work conflicting with the required surveillance intervals. The licensee also determined that the radiator replacement work is in a critical )ath activity and any delay would cause an extension of the outage. When it )ecame evident that the most desirable action was to postpone 3erformance of the EDG surveillances, the licensee promptly informed t1e NRC staff of the situation.
On the basis of the above discussion, the staff finds that (1) exigent circumstances exist, as provided for in 10 CFR 50.91(a)(6) in that the licensee and the Commission must act quickly and time does not permit the
-Commission to publish a Federal Reaister notice allowing 30 days for prior public comment, and (2) the licensee did not deliberately or negligently cause the exigent situation.
The Commission noticed the licensee's application for amendments in the Federal Register on August 12, 1997 (62 FR 43189), at which time the Commission made a proposed finding that the amendments involved no significant hazards consideration and there has been no public comment in response to that notice.
5.0 FINAL NO SIGNIFICANT HAZARDS CONSIDERATION
DETERMINATION The Commission's regulations in 10 CFR 50.92 provide that the Commission may make a final determination that a license amendment involves no significant hazards considerations if operation of the facility in accordance with the amendment would not (1) involve a significant increase in the probability or consequences of an accident previously evaluated: or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of
- safety, 1.
The proposed change will not significantly increase the probability or consequences of an accident previously evaluated.
An increase in the surveillance interval from 31 days to 60 days does not significantly decrease the reliability of the EDGs nor degrade their
-ability-to perform their intended safety function when required. Based on data obtained over time the EDGs at CR-3 have an excellent record of availability. This extension of the interval will be applied to only one surveillance interval on each EDG and will not be in effect after November 23, 1997.
CR-3 obtains data from surveillance testing and operational experience and maintains records of the unavailability of the EDGs and the relays.
CR-3 mtritors a parameter referred to as Unavailability Performance Indicator, defined as the sum of known and estimated unavailable hours divided by hours system reguired. As a limited scope effort the records for 1994 through June, 1997 were reviewed. This data indicates very low values of the performance indicator, with the average value for-the 14 quarters being 0.005. The yearly goal for this performance indicator was
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met in the years reviewed.
In total these records reflect low unavailability; i.e., high availability.
The EDG that is to remain operable during radiator replacement on the other diesel will be surveilled in accordance with SR 3.3.8.1 and SR 3.8.1.3 just prior to initiation of the EDG outage. This test will ensure its operability.
Based on the high availability of the EDGs at-CR-3 and the fact that this is a one-time extension of the interval for each EDG it is concluded that this requested extension of the surveillance interval will not result in a significant increased probability or consequences of previously evaluated accidents.
- 2.
The proposed changes will not create the possibility of a new or-different kind of accident from any accident previously evaluated.
This request for technical specification changes addresses the interval for performance of the surveillances on a one-time basis for each diesel generator. This requested change to the license by itself does not
, involve a modification to the EDG, The modifications of the EDGs to replace the radiator have been evaluated pursuant to 10 CFR 50.59.
The conclusion of that evaluation is that the radiator replacement does not create the possibility of a new or different kind of accident from any accident previously evaluated.
Based on the above FPC concludes that changing the surveillance frequency will not create the possibility of a new or different kind of accident.
3.
The proposed change will not involve a significant reduction to the margin of safety.
As discussed above in item number one. the EDGs at CR-3 have a record of high availability. The high availability reflected in those records provides reasonable assurance that the operable EDGs will remain operable during the extended interval between surveillances.
By not being required to perform the tests FPC will maintain a higher level of safety than would be possible if the tests were performed.
Based on the high availat.111ty of the EDGs and the fact that this extension of the surveillance frequency is for one interval only FPC concludes that changing the surveillance-interval does not result in a significant
' reduction to the margin of safety.
Based on its review, the staff concurs with the licensee's analysis and concludes that the three standards of 10 CFR 50.92(c) are satisfied. Based on the above. the comission has made a final determination that the proposed amendments involve no significant hazards consideration.
6.0
SUMMARY
On the basis of the above, the staff concludes that the proposed TS Change to 3.3.8.1 (Channel Functional Test) is acceptable.
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5 6,0 EI61E CONSULTATION Based upon written notice of the proposed amendment, the Florida State official had no' coments.
6.0 ENVIRONMENTAL CONSIDERATION
S The amendment changes requirements with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes the 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-l proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (62 FR 30632).. 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 ass.esment need be prepared in connection with the issuance of the amendments.
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7.0 CONCLUSION
The Comission has concluded, based on the considerations discussed abov=,
that:- (1) there is reasonable assurance that the health M a safet public will not be endangered by operation in the proposed manner y of the (2) seh activities will be conducted in compliance with the Commission's regulations, and-(3) the issuance of these amendments will not be inimical to the commoa defense and security or to the health and safety of the public.
Principal Contributors: Saba Saba, and L. Raghavan NRR Date: August 29, 1997 o