ML17229B094
| ML17229B094 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 04/08/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML17229B093 | List: |
| References | |
| NUDOCS 9904160109 | |
| Download: ML17229B094 (14) | |
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UNITED STATES NUCLEAR REGULATORY COMMiSSION WASHINGTON, D.C. 2d555-0001 SAFETY EVALUATIONBY THE OFFICE OF'NUCLEAR REACTOR REGULATION RELATED TO AMENDMENTNO. 100 TO FACILITYOPERATING LICENSE NO. NPF-1 6 FLORIDA POWER AND LIGHTCOMPANY ET AL.
ST. LUCIE PLANT UNIT NO. 2 DOCKET NO. 50-389
1.0 INTRODUCTION
'y a [[letter::L-98-115, Application for Amend to License NPF-16,removing Requirement for SITs to Be Operable in Mode 4,which Will Minimize Potential for Inadvertent SIT Discharge During RCS Cooldown/ Depressurization Evolutions|letter dated May 27, 1998]], as supplemented by a letter dated October 9, 1998, Florida Power and Light Company (FPL) requested an amendment to its Facility Operating License No.
NPF-16 for St. Lucie, Unit 2, to remove the technical specification (TS) requirement for safety injection tank (SIT) operability in Mode 4 (hot shutdown).
This safety evaluation (SE) constitutes the Nuclear Regulatory Commission's (NRC or Commission) evaluation of FPL's request.
The October 9, 1998 supplemental letter provided clarifying information that did not change the initial proposed no significant hazards consideration determination.
~ In the 1970s, there was little consideration of loss of coolant accidents (LOCAs) during Mode 4 operation because Mode 1 LOCAs were assumed to be limiting, and many operating licenses and TSs were based on this assumption.
As a result, typical licensing bases did not include LOCA analyses for Mode 3 (hot standby) and Mode 4 operation, and emergency core cooling system (ECCS) TS requirements are less stringent during Modes 3 and 4 consistent with the reduced safety concern.
Aspects of the potential need for ECCS capability changed in the mid-1980s with consideration of such actions as blocking safety injection (Sl) at approximately 2000 psig when reducing reactor coolant system (RCS) pressure, constraints due to locking out some high pressure Sl (HPSI) pumps because of low temperature high pressure concerns, use of low pressure Sl (LPSI) pumps for shutdown cooling (SDC), and the potential need for operator action to initiate Sl during Mode 3 and Mode 4 operation.
The Westinghouse (W) Owners Group applied probabilistic risk assessment techniques to large break LOCA during Mode 3 and Mode 4 operation and concluded that the risk of core damage is significantly smaller in these modes than during Mode 1 (power operation).
It then performed thermal-hydraulic analyses for small-break LOCA and concluded there was at least 10 minutes available for operators to take action to mitigate the potential effects of such a LOCA during shutdown operation.
In 1995, NRC review of this work was postponed due to the staff's plan to address this issue as part of a potential shutdown operations rule.
In 1997, the Commission decided to address shutdown issues as part of the maintenance rule activities, and the shutdown rule was not issued.
Although the staff has not written specific guidance for the ECCS capability required to meet the maintenance rule during Modes 3 and 4 operation, it has approved standard TSs (STSs) i904XS0i09 9eoe08 PDR ADQCK 05000289 p
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.2-which, for example, state that the single failure criterion is not applicable to the ECCS during Mode 4 operation.
The bases for the STSs are applicable to the licensee's request.
W SITs are typically pressurized to approximately 600 psig and are isolated at approximately 1000 psig to prevent injection during routine RCS depressurization.
Some Combustion Engineering (CE) plants, such as St. Lucie Unit 1, have SIT pressures of approximately 200 psig and SITs are not requiredby TSs for Mode 4 operation.
This is not the case for St. Lucie, Unit 2, where nominal SIT press'ure is approximately 500 psig and SITs are presently required during Mode 4 operation.
Consequently, St. Lucie, Unit 2, SIT pressure is reduced during RCS depressurization to prevent injection while the SITs remain capable of injecting if a LOCA occurs, and SITs are isolated at 276 psia when SDC can be initiated. The requested change would allow Unit 2's SITs to be isolated earlier, and the SIT depressurization process to prevent an inadvertent discharge would no longer be necessary.
2.0 EVALUATION The proposed license amendment would change the Limiting Condition for Operation Applicabilityfound in TS Section 3/4.5.1, "Safety Injection Tanks," on page 3/4 5-1, by modifying limiting condition for operation 3.5.1, applicability statement, which currently reads, "APPLICABILITY: MODES 1, 2, 3*, and 4*." to now read, "APPLICABILITY: MODES 1, 2, and 3*." The paragraph at the bottom of page 3/4 5-1, designated with an asterisk to be associated with the previously mentioned applicability statements, will be modified to remove the last sentence.
The last sentence in that paragraph currently reads, "In Mode 4 with pressurizer pressure less than 276 psia, the safety injection tanks may be isolated."
The requested change removes the operability requirement for SITs during Mode 4. The following paragraphs evaluate separately the information provided in the two referenced FPL letters.
In its letter of May 27, 1998, the licensee stated that removal of the SIT requirement is consistent with both the standard TSs for CE plants and the TSs for St. Lucie Unit 1.
FPL's [[letter::L-98-115, Application for Amend to License NPF-16,removing Requirement for SITs to Be Operable in Mode 4,which Will Minimize Potential for Inadvertent SIT Discharge During RCS Cooldown/ Depressurization Evolutions|May 27, 1998 letter]] stated that removing the Mode 4 operability requirement for SITs was based on an engineering evaluation which concluded that, in the event of a large-break LOCA, the flow rate from one HPSI pump was sufficient to meet applicable requirements.
It apparently used this justification on the basis of the original licensing analyses that addressed SIT operation.
However, FPL based its evaluation on initiation of HPSI at 30 seconds following initiation of the break, consistent with automatic initiation. Automatic HPSI initiation in Mode 4 would not normally be expected and operator initiation would normally be necessary.
Since the information and justifications are based upon a 30-second initiation time to justify this proposal, the staff reque'sted that FPL address manual initiation of HPSI in a supplemental submittal.
The 30 second response time is associated with the automatic initiation of safety injection equipment in response to a large break LOCA condition.
In order to depressurize the reactor coolant system during a normal shutdown, it is necessary to block this initiation since failure to do so would result in inappropriate safety injection and numerous complications.
Requiring an
- operator response in 30 seconds has been recognized for years as impractical and is not required.
In its October 9, 1998 supplement, FPL addressed HPSI initiation at 10 minutes and referenced a study of W plants and a CE study that FPL claimed to be bounding for St. Lucie, Unit 2.
-'3-Although some rationalization was provided that the W results apply to St. Lucie, the logic was insufficient for NRC to accept applicability of W plant calculations to St. Lucie. The CE calculations were stated to have been performed "... with the realistic evaluation model (REM) for small-break LOCA that was submitted to the NRC for review in 1988" and "Acalculational uncertainty of 150 F, determined for the licensing application of the REM model, was applied to the shutdown LOCA analysis." Although this model was submitted to the NRC for review, the submittal was withdrawn before the NRC issued an acceptability finding. The referenced material provides a general background of behavior typical of Mode 4 operation, but it may not be specifically applicable to St. Lucie, Unit 2. Consequently, the NRC has not credited these analysis results for purposes of meeting licensing requirements.
For Mode 4, the CE standard TSs reflect a reduction in ECCS operational requirements from Mode 3 requirements that is justified by the reduced probability of a design basis accident, the availability of sufficient time for manual actuation of the required ECCS, and the stable conditions associated with Mode 4 operation.
Consequently, only one ECCS train, consisting of one HPSI system, is required by standard TS in this mode and it is recognized that automatic Sl actuation signals willnot be available.
The LPSI pumps may therefore be released from the ECCS train for use in shutdown cooling. The standard TS also states that protection against single failures is not relied upon during this Mode of operation.
At St. Lucie, Unit 2, water makeup following LOCAs would be provided by HPSI, a capability addressed by the TSs which requires one operable HPSI pump and one operable LPSI pump.
The LPSI pump, operating in shutdown heat removal mode, may be lost as a result of the LOCA. Consequently, the HPSI pump may represent the TS-required means of adding water to the RCS. As previously mentioned, operator action is assumed to be necessary to initiate HPSI. Further, in LOCAs where pressurization occurs, operator action may be necessary to control RCS pressure while continuing to assure core cooling. Consequently, the NRC conducted a brief audit of FPL Off-Normal Procedure 2-ONP-01.01, Revision 4, with respect to HPSI, LPSI, and RCS pressure control actions to assess the licensee's provision for HPSI operation.
The staff finds these actions are addressed and are consistent with the CE methodology of ensuring control of the safety functions of reactivity, electrical power, RCS inventory, RCS pressure, RCS and core heat removal, containment isolation, and containment temperature and pressure.
Potential changes in this procedure would be controlled by 10 CFR 50.59 and thus the procedure willcontinue to be applicable.
10 CFR 50.36(c)(2)(ii) states that a TS must be established for each item that meets any one of four criteria. The criteria and the staff finding with respect to each are as follows:
(1)
Installed instrumentation that is used to detect, and indicate in the control room, a significant abnormal degradation of the reactor coolant pressure boundary.
The licensee request does not involve instrumentation.
(2)
A process variable, design feature, or operating restriction that is an initial condition of a design basis accident or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.
There are no design basis or transient analyses in the licensing basis that are directly applicable to Mode 4 operation.
The Mode 1 analyses are assumed to be bounding for Mode 4 operation.
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(3)
A,structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier. There are no design basis or transient analyses in the licensing basis that are directly applicable to Mode 4 operation.
The Mode 1 analyses are assumed to be bounding for Mode 4 operation.
(4)
A structure, system, or component which operating experience or probabilistic risk assessment has shown to be significant to public health and safety. To our knowledge, there is no operating experience or probabilistic risk assessment that shows the safety injection tank has significance during Mode 4 operation with respect to public health and safety.
Consequently, there is no 10 CFR 50.36 requirement for a TS applicable to the SIT during Mode 4 operation.
3.0 STAFF CONCLUSION The proposed amendment is consistent with the requirements of 10 CFR 50.36 since the proposed amendment is consistent with analyses and evaluations included in the safety analysis report and amendments thereto, it only applies when the reactor is in the referenced shutdown modes, appropriate modal inter-relatioriships are referenced, automatic actuation of safety injection equipment is not required, and planned operator action is consistent with correction of an abnormal situation before a safety limit is exceeded.
The 30 second response time is associated with the automatic initiation of safety injection equipment in response to a large break LOCA condition. An operator response in 30 seconds has been recognized for years as impractical and is not required.
Consequently, the 30 second response requirement as a license condition would be inappropriate and is not required for the staff to approve the amendment request.'he NRC finds that, consistent with the CE standard TSs, the TSs for St. Lucie Unit 1, and the requirements of 10 CFR 50.36, the previous considerations justify the licensee's request for St. L'ucie Unit 2. Therefore, the proposed change is acceptable.
4.0 STATE CONSULTATION
Based upon a letter dated March 8, 1991, from Mary E. Clark of the State of Florida, Department of Health and Rehabilitative Services, to,Deborah A. Miller, Licensing Assistant for the U.S. Nuclear Regulatory Commission, the State of Florida does not desire notification of issuance of license amendments.
5.0 ENVIRONMENTALCONSIDERATION These 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 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 amendments involve no significant hazards consideration and there has been no public comment on such finding (63 FR 40556). Accordingly, these amendments meet the eligibilitycriteria 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 these amendments.
6.0 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 willnot be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: W. Lyon Date:
April 8, 1999
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I 6 REFERENCES I
Walsh, Lawrence A., "Submittal of WCAP-12476, 'Evaluation of LOCA During Mode 3 and Mode 4 Operation for Westinghouse NSSS,'" letter to Chief, Regulatory Publications Branch, NRC, from Chairman, W Owners Group, OG-91-61, November 21,
, 1991.
Liberatori, Louis F. Jr., "Review of WCAP-12476, 'Evaluation of LOCA During Mode 3 and Mode 4 Operation for Westinghouse NSSS,'" letter to Robert C. Jones, Chief, Reactor Systems Branch, Office of Nuclear Reactor Regulation, NRC, from W Owners Group Analysis Subcommittee Chairman, OG-95-069, August 25, 1995.
Mr. TF. Plunkett Florida Power and Light Company ST. LUCIE PLANT CC:
Senior Resident Inspector St. Lucie Plant U.S. Nuclear Regulatory Commission P.O. Box 6090 Jensen Beach, Florida 34957 Joe Myers, Director Division of Emergency Preparedness Department of Community Affairs 2740 Center view Drive Tallahassee, Florida 32399-2100 M. S. Ross, 'Attorney Florida Power 8 Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. Douglas Anderson County Administrator St. Lucie County 2300 Virginia Avenue Fort Pierce, Florida 34982 Mr. WilliamA. Passetti, Chief Department of Health Bureau of Radiation Control 2020 Capital Circle, SE, Bin PC21 Tallahassee, Florida 32399-1741
, Regional Administrator Region II U.S. Nuclear Regulatory Commission 61 Forsyth Street,- SW., Suite 23T85 Atlanta, GA 30303-3415 J. A. Stall, Site Vice President St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957 Mr. R. G. West Plant General Manager St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957 Mr. Leonard D. Wert U.S. Nuclear Regulatory Commission 61 Forsyth Street, SW., Suite 23T85 Atlanta, GA 30303-3415 E. J. Weinkam Licensing Manager St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957 Mr. John Gianfrancesco Manager, Administrative Support and Special Projects P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. Rajiv S. Kundalkar Vice President - Nuclear Engineering Florida Power 8 Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. J. Kammel Radiological Emergency Planning Administrator Department of Public Safety 6000 SE. Tower Drive Stuart, Florida 34997
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.c. 20555-0001 April 8, 1999 MEMORANDUMTO: BiWeekly Notice Coordinator FROM:
SUBJECT:
William C. Gleayes, Project Manager, Section 2 Project Directorate II Division of Licensing Project Management REQUEST FOR PUBLICATION IN BIWEEKLYFR NOTICE-NOTICE OF ISSUANCE OF AMENDMENTTO FACILITY OPERATING LICENSE (TAC NO. MA2122)
Florida Power and Li ht Com an et al. Docket No. 50-389 St. Lucie Plant Unit No. 2, St. Lucie Count Florida Date of a lication for amendment:
May 27, 1998, as supplemented October 9, 1998.
Brief descri tion of amendment: Deletes the requirement for operability of the safety injection tanks in Mode 4 of reactor operation.
Date of Issuance:
Aril8 1999 Effective Date: Amendment is effective within 30 days of receipt.
Amendment No.:
100 Facilit 0 eratin License No. NPF-16: Amendmentrevisedthe Technical Specifications.
Date of initial notice in FEDERAL REGISTER: July 29, 1998 (63 FR 40556). The October 9, 1998 supplemental letter provided clarifying information that did not change the initial proposed no significant hazards consideration determination.
The Commission's related evaluation of the amendment is contained in a Safety Evaluation dated April 8, 1999.
No significant hazards consideration comments received:
No.
Local Public Document Room location: Indian River Junior College Library, 3209 Virginia Avenue, Fort Pierce, Florida 34954-9003
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