ML021080050
| ML021080050 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 07/29/2002 |
| From: | Boska J NRC/NRR/DLPM/LPD1 |
| To: | Skolds J Exelon Generation Co |
| Boska J, NRR, 301-415-2901 | |
| References | |
| TAC MB4624, TAC MB4625 | |
| Download: ML021080050 (21) | |
Text
July 29, 2002 Mr. John L. Skolds, President and Chief Nuclear Officer Exelon Nuclear Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348
SUBJECT:
PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3 - ISSUANCE OF AMENDMENT RE: HEAT SINK TEMPERATURE LIMITS (TAC NOS.
MB4624 AND MB4625)
Dear Mr. Skolds:
The Commission has issued the enclosed Amendments Nos. 244 and 248 to Facility Operating License Nos. DPR-44 and DPR-56 for the Peach Bottom Atomic Power Station, Units 2 and 3.
These amendments consist of changes to the Technical Specifications (TSs) in response to your application dated March 19, 2002.
These amendments allow plant operation to continue if the temperature of the normal heat sink (NHS) exceeds the TS limit of 90 F provided that the NHS temperature averaged over the previous 24-hour period is verified at least once per hour to be less than or equal to 90 F, and the NHS temperature does not exceed a maximum value of 92 F. The format for this change had been previously approved by the Nuclear Regulatory Commission for the Standard TSs as per TS Task Force (TSTF) change TSTF-330, Revision 3, Allowed Outage Time - Ultimate Heat Sink, on October 13, 2000. In addition, an administrative change removes references to a temporary TS change that expired on May 31, 2000.
A copy of the safety evaluation is also enclosed. Notice of Issuance will be included in the Commission's Biweekly Federal Register Notice.
Sincerely,
/RA/
John P. Boska, Project Manager, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-277 and 50-278
Enclosures:
- 1. Amendment No. 244 to DPR-44
- 2. Amendment No. 248 to DPR-56
- 3. Safety Evaluation cc w/encls: See next page
Peach Bottom Atomic Power Station, Units 2 and 3 cc:
Vice President, General Counsel and Secretary Exelon Generation Company, LLC 300 Exelon Way Kennett Square, PA 19348 Site Vice President Peach Bottom Atomic Power Station Exelon Generation Company, LLC 1848 Lay Road Delta, PA 17314 Plant Manager Peach Bottom Atomic Power Station Exelon Generation Company, LLC 1848 Lay Road Delta, PA 17314 Regulatory Assurance Manager Peach Bottom Atomic Power Station Exelon Generation Company, LLC 1848 Lay Road Delta, PA 17314 Resident Inspector U.S. Nuclear Regulatory Commission Peach Bottom Atomic Power Station P.O. Box 399 Delta, PA 17314 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. Roland Fletcher Department of Environment Radiological Health Program 2400 Broening Highway Baltimore, MD 21224 Correspondence Control Desk Exelon Generation Company, LLC 200 Exelon Way, KSA 1-N-1 Kennett Square, PA 19348 Chief-Division of Nuclear Safety PA Dept. of Environmental Protection P.O. Box 8469 Harrisburg, PA 17105-8469 Board of Supervisors Peach Bottom Township 575 Broad Street Ext.
Delta, PA 17314-9203 Mr. Richard McLean Power Plant and Environmental Review Division Department of Natural Resources B-3, Tawes State Office Building Annapolis, MD 21401 Dr. Judith Johnsrud National Energy Committee Sierra Club 433 Orlando Avenue State College, PA 16803 Manager-Financial Control & Co-Owner Affairs Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, NJ 08038-0236 Manager Licensing-Limerick and Peach Bottom Exelon Generation Company, LLC Nuclear Group Headquarters Correspondence Control P.O. Box 160 Kennett Square, PA 19348 Director - Licensing Mid-Atlantic Regional Operating Group Exelon Generation Company, LLC Nuclear Group Headquarters Correspondence Control P.O. Box 160 Kennett Square, PA 19348
Peach Bottom Atomic Power Station, Units 2 and 3 cc:
Vice President-Licensing and Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Senior Vice President Mid-Atlantic Regional Operating Group Exelon Generation Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348 Senior Vice President, Nuclear Services Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Vice President, Mid-Atlantic Operations Support Exelon Generation Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348 Manager License Renewal Exelon Generation Company, LLC 200 Exelon Way Kennett Square, PA 19348
- See previous concurrence OFFICE PM/PD1-2 LA/PD1-2 RORP*
SPLB*
OGC*
ASC/PD1-2 NAME JBoska MOBrien RDennig JHannon AHodgdon JZimmerman DATE 7-23-02 7/23/02 6/19/02 6/25/02 6/27/02 7/25/02
EXELON GENERATION COMPANY, LLC PSEG NUCLEAR LLC DOCKET NO. 50-277 PEACH BOTTOM ATOMIC POWER STATION, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 244 License No. DPR-44 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Exelon Generation Company, LLC (Exelon Generation Company), and PSEG Nuclear LLC (the licensees), dated March 19, 2002, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in 10 CFR Chapter I.
B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.
The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.
2.
Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C(2) of Facility Operating License No. DPR-44 is hereby amended to read as follows:
(2)
Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 244, are hereby incorporated in the license. Exelon Generation Company shall operate the facility in accordance with the Technical Specifications.
3.
This license amendment is effective as of its date of issuance and shall be implemented within 30 days.
FOR THE NUCLEAR REGULATORY COMMISSION
/RA/
Jacob I. Zimmerman, Acting Chief, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications Date of Issuance: July 29, 2002
ATTACHMENT TO LICENSE AMENDMENT NO. 244 FACILITY OPERATING LICENSE NO. DPR-44 DOCKET NO. 50-277 Replace the following pages of the Appendix A Technical Specifications with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
Remove Insert 3.7-3 3.7-3 B 3.7-8 B 3.7-8 B 3.7-8a B 3.7-13 B 3.7-13
EXELON GENERATION COMPANY, LLC PSEG NUCLEAR LLC DOCKET NO. 50-278 PEACH BOTTOM ATOMIC POWER STATION, UNIT 3 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 248 License No. DPR-56 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Exelon Generation Company, LLC (Exelon Generation Company), and PSEG Nuclear LLC (the licensees), dated March 19, 2002, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in 10 CFR Chapter I.
B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.
The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.
2.
Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C(2) of Facility Operating License No. DPR-56 is hereby amended to read as follows:
(2)
Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 248, are hereby incorporated in the license. Exelon Generation Company shall operate the facility in accordance with the Technical Specifications.
3.
This license amendment is effective as of its date of issuance and shall be implemented within 30 days.
FOR THE NUCLEAR REGULATORY COMMISSION
/RA/
Jacob I. Zimmerman, Acting Chief, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications Date of Issuance: July 29, 2002
ATTACHMENT TO LICENSE AMENDMENT NO. 248 FACILITY OPERATING LICENSE NO. DPR-56 DOCKET NO. 50-278 Replace the following pages of the Appendix A Technical Specifications with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
Remove Insert 3.7-3 3.7-3 B 3.7-8 B 3.7-8 B 3.7-8a B 3.7-13 B 3.7-13
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 244 TO FACILITY OPERATING LICENSE NO. DPR-44 AND AMENDMENT NO. 248 TO FACILITY OPERATING LICENSE NO. DPR-56 EXELON GENERATION COMPANY, LLC PSEG NUCLEAR LLC PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3 DOCKET NOS. 50-277 AND 50-278
1.0 INTRODUCTION
By letter dated March 19, 2002, Exelon Generation Company, LLC (the licensee), submitted a request for changes to the Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, Technical Specifications (TSs). The requested changes revise the action requirement provisions of TS Limiting Condition for Operation (LCO) 3.7.2, Emergency Service Water (ESW) System and Normal Heat Sink, to allow continued plant operation with short-term elevated Normal Heat Sink (NHS) temperature. In addition, an administrative change to the Peach Bottom TSs removes references to a temporary TS change that expired on May 31, 2000. This temporary TS change extended the completion time for restoring an inoperable ESW system to operable status to 14 days by adding a footnote to the bottom of the page.
This administrative change will remove the expired footnote.
PBAPS Units 2 and 3 have previously experienced elevated NHS temperatures. During the summer of 1999, the NHS temperature for the intake of PBAPS Units 2 and 3 approached the 90 F temperature limit, and on August 1, 1999, reached 89 F. Exceeding the limit would have resulted in a required shutdown of PBAPS Units 2 and 3. Therefore, on August 6, 1999, the licensee submitted to the Nuclear Regulatory Commission (NRC) a request for exigent amendments to provide a short-term increase in the NHS temperature limit. However, the river temperature improved and the amendment request was withdrawn. A shutdown of both units, due to NHS high temperature, would result in an unnecessary plant transient and increase the possibility of a disturbance to the PBAPS Units 2 and 3 off-site electrical power sources and the regional electrical power distribution system at a time of potential grid vulnerability due to maximum generation requirements. The licensee is proposing this TS change in anticipation of other potentially hot, dry summers.
The format of this change was proposed by the Nuclear Energy Institutes (NEIs) TS Task Force (TSTF) as a change to the Standard Technical Specifications (STS), NUREG-1433, Standard Technical Specifications General Electric Plants, BWR/4, in change TSTF-330, Revision 3, Allowed Outage Time - Ultimate Heat Sink. The NRC approved TSTF-330, Revision 3, on October 13, 2000. The change approved in TSTF-330, Revision 3, has been incorporated by the NRC into the current version of the STS, NUREG-1433, Revision 2, dated April 30, 2001. Specifically, the proposed action requirements for PBAPS Units 2 and 3 permit plant operation above the current NHS temperature limit of 90 F on the conditions that (a) the NHS temperature averaged over the previous 24-hour period is verified at least once per hour to be less than or equal to 90 F, and (b) the NHS temperature does not exceed a maximum value of 92 F. The TS Bases are revised accordingly. Note that the NHS at Peach Bottom, as described in TS LCO 3.7.2, corresponds to the Ultimate Heat Sink as described in STS LCO 3.7.2.
2.0 REGULATORY EVALUATION
Licensees have historically experienced elevated heat sink temperature conditions during prolonged periods of hot, dry weather and, on occasion, TS temperature limits have been exceeded. Typically these situations are infrequent, of short duration, and do not pose a challenge to accident mitigating systems and components. However, when these conditions arise, prompt action is required by licensees to address TS requirements, which typically include a request for the NRC to exercise enforcement discretion. The NEIs TSTF proposed a change to the STS requirements in order to deal more efficiently with short-lived elevated heat sink temperatures that exceed accident analysis assumptions. The NEI TSTF submitted the proposed STS change as TSTF-330, Allowed Outage Time--Ultimate Heat Sink, and the NRC approved Revision 3 of TSTF-330 for use by licensees on October 13, 2000. Plants that have been issued the TSTF-330 change include Millstone Unit 2, in Amendment No. 257, dated May 31, 2001.
TSTF-330 allows licensees to adopt an averaging approach for satisfying the heat sink temperature limit as long as certain criteria are met. During periods when the temperature of the heat sink exceeds the TS limit, continued operation is allowed provided that: (a) the licensee confirms on an hourly basis that the rolling 24-hour average heat sink temperature does not exceed the TS temperature limit, and (b) the heat sink temperature does not exceed a new peak temperature limit that is established based on equipment limitations. TSTF-330 is not applicable for all situations, and licensees who wish to adopt this change to the STS must either confirm that the following conditions are satisfied, or provide justification for any exceptions that are identified:
The heat sink is not relied upon for immediate heat removal (such as to prevent containment overpressurization), but is relied upon for longer-term cooling such that the temperature averaging approach continues to satisfy the accident analysis assumptions for heat removal over time.
When the heat sink is at the proposed maximum allowed value, equipment that is relied upon for accident mitigation, anticipated operational occurrences, or for safe shutdown, will not be adversely affected and is not placed in alarm condition or limited in any way at this higher temperature.
Plant-specific assumptions, such as those that were credited in addressing station blackout and Generic Letter 96-06, Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions, have been adjusted (as necessary) to be consistent with the maximum allowed heat sink temperature that is proposed.
Cooling water that is being discharged from the plant (either during normal plant operation, or during accident conditions) does not affect the heat sink intake water temperature (typical of an infinite heat sink, but the location of the intake and discharge connections, and characteristics of the heat sink can have an impact).
The licensees submittal dated March 19, 2002, requests a change to TS 3.7.2 to adopt the heat sink temperature averaging approach described in TSTF-330 and NUREG-1433. The licensee proposed to establish 92 F as the maximum allowed heat sink temperature based on equipment limitations, and has confirmed that the conditions required by TSTF-330, Revision 3, are satisfied for PBAPS Units 2 and 3.
3.0 TECHNICAL EVALUATION
The NHS for PBAPS Units 2 and 3 is the Susquehanna River. That section of the Susquehanna River has a downstream dam (Conowingo Dam), which results in a widening of the river and better control of river level. The section upstream of Conowingo Dam is referred to as Conowingo Pond. The NHS supplies the cooling water for the nonsafety-related Condenser Circulating Water System and nonsafety-related Service Water (SW) System. The NHS also supplies the cooling water for the safety-related High-Pressure Service Water (HPSW) system and the safety-related Emergency Service Water (ESW) system. PBAPS Units 2 and 3 also have a mechanical draft three-cell cooling tower, which functions as an Emergency Heat Sink (EHS). The function of the EHS is to provide heat removal capability so that the PBAPS Units 2 and 3 reactors can be maintained in a safe shutdown condition in the event of the unavailability of the NHS (e.g., due to the failure of the Conowingo Dam on the Susquehanna River). Since the EHS must be manually aligned to provide the heat removal capability, it is not relied upon for mitigation of reactor accidents.
3.1 Affected Equipment The following safety-related components are cooled by the NHS following an accident or abnormal operational transient:
HPSW System:
Residual Heat Removal (RHR) Heat Exchangers HPSW Pump Motor Oil Coolers ESW System:
Emergency Diesel Generator (EDG) Heat Exchangers RHR Pump Room Coolers RHR Pump Seal Coolers Core Spray (CS) Pump Room Coolers CS Pump Motor Oil Coolers High Pressure Coolant Injection (HPCI) Pump Room Coolers Reactor Core Isolation Cooling (RCIC) Pump Room Coolers The licensee stated in the application that engineering calculations demonstrate that the HPCI and RCIC Pump Room Coolers, and the RHR Pump Seal Coolers are not required to support operability of their associated safety system. Therefore, this equipment is not addressed in the following evaluation.
TS 3.7.2, "Emergency Service Water (ESW) System and Normal Heat Sink," requires the NHS to be Operable in Modes 1, 2, and 3, i.e., Power Operation, Startup, and Hot Shutdown, respectively. In accordance with the current TS Surveillance Requirement (SR) 3.7.2.2, the NHS temperature limit for operability is 90 F. The purpose of this requirement is to ensure that the heat removal capability of the ESW and HPSW Systems is adequate to maintain the design-basis temperatures of safety-related equipment relied upon to mitigate the consequences of an accident or operational transient.
The proposed TS change maintains the original NHS design-basis water temperature of 90 F, but allows for this limit to be temporarily exceeded provided that the 24-hour (rolling) average does not exceed 90 F and the peak temperature does not exceed 92 F. This change does not alter any assumptions on which the plant safety analysis is based. The affected components were originally designed with margin that allows for cooling water temperatures greater than the plant design basis of 90 F, although no credit had previously been taken for this margin. In determining the capability of the affected heat exchangers, the original equipment design conservatively assumed a certain degree of equipment degradation (i.e.,
fouling, tube plugging). Periodic testing and cleaning are performed to verify that these design conditions assumed for the affected heat exchangers are not reached. The licensee performed technical evaluations in support of the proposed TS change and determined that a reasonable degree of equipment degradation can still be assumed while demonstrating that the affected safety-related components could continuously perform their design function at cooling water temperatures up to 92 F. The licensee stated in the application that new limits for equipment degradation will be procedurally controlled to ensure that the affected components would continue to function at the increased cooling water temperature. These limits will not require increased testing or cleaning of heat exchangers beyond the normal intervals to ensure that design margins are maintained. All heat exchangers addressed in this evaluation will be maintained capable of removing their respective design-basis heat loads at the elevated (92 F) cooling water temperature in accordance with the PBAPS Units 2 and 3 program implemented in response to GL 89-13, Service Water System Problems Affecting Safety-Related Equipment.
RHR Heat Exchangers The PBAPS Units 2 and 3 plant-specific analyses for the design-basis accidents (DBAs) and non-break events that require containment cooling assume a minimum RHR heat exchanger heat transfer capability that is based upon a conservative amount of overall thermal fouling and a set percentage of the tube population plugged. The present design-basis maximum cooling water inlet temperature is 90 F. The actual fouling factors determined from test data and engineering analysis are used to verify operability of the heat exchangers by comparison to the equipment design-basis fouling factor. The material condition of the RHR heat exchangers is maintained better than assumed in determining the design-basis heat transfer capability. This margin in material condition is used to revise the fouling factor acceptance criteria and demonstrate that the RHR heat exchangers are capable of maintaining the required heat transfer capability for NHS temperatures up to 92 F. The licensee stated in the application that compliance with the acceptance criteria for fouling of the RHR heat exchangers is controlled by procedures thus ensuring that the limit for heat exchanger fouling is not reached.
By maintaining the design-basis capability of the RHR heat exchangers (at the increased cooling water temperature), the heat exchanger capability that has been assumed in evaluating plant events is maintained.
EDG Heat Exchangers In response to an equipment design deficiency identified during GL 89-13 heat exchanger performance testing for the EDGs (reference PBAPS Units 2 and 3 Licensee Event Report 2-00-002), PBAPS Units 2 and 3 have made a hardware change to each EDG air coolant system that has corrected for the inherent design deficiency and has increased equipment design margins relative to cooling water temperature limits. The licensee performed engineering analyses to establish permissible fouling factors for the EDG heat exchangers based upon the limiting conditions for electrical loading, combustion air inlet temperature and cooling water flow and temperature. Evaluation by the licensee of test data following the hardware changes discussed previously has demonstrated that sufficient margin exists between measured fouling and permissible fouling. Therefore, the EDG heat exchangers will perform their design-basis function at cooling water inlet temperatures up to 92 F at any point during the heat exchanger operating cycle between scheduled cleanings. The licensee stated in the application that compliance with the acceptance criteria for fouling of the EDG heat exchangers is controlled in accordance with the GL 89-13 testing program, thereby ensuring that the established limits for heat exchanger fouling are not reached. By maintaining the design-basis capability of the EDG (at the increased cooling water temperature), the ability of this system to provide onsite emergency AC power, as required, is maintained.
RHR and CS Pump Room Coolers The licensee evaluated the RHR and CS pump room coolers via engineering calculations to be capable of maintaining acceptable pump room post-accident temperature profiles assuming the room coolers in each pump room are supplied cooling water at a conservative temperature of 95 F. The licensee stated in the application that periodic testing is performed to verify that the equipment performance assumed in the analyses is maintained.
HPSW/CS Pump Motor Oil Coolers The licensees review of the original equipment design requirements for the HPSW and CS pump motor oil coolers indicates that the coolers have been conservatively designed with respect to the present 90 F NHS temperature limit. Review of historical and recent test data considering the increased cooling water temperature limit has shown that sufficient margin exists for the affected motor oil coolers to perform their design-basis function at cooling water inlet temperatures up to 92 F. The licensee stated in the application that periodic testing is performed to verify that the required equipment capability is maintained at the NHS temperature limit.
3.2 Condition One from TSTF-330, Revision 3 The heat sink is not relied upon for immediate heat removal (such as to prevent containment overpressurization), but is relied upon for longer-term cooling such that the temperature averaging approach continues to satisfy the accident analysis assumptions for heat removal over time.
The containment air coolers at PBAPS Units 2 and 3 are not credited in the plant safety analysis for post-accident containment heat removal. At PBAPS Units 2 and 3, the suppression pool cooling and containment spray modes of the RHR System are designed to provide long-term post-accident containment heat removal. As discussed above, the design-basis capability of the RHR heat exchangers that is assumed in evaluating the plant events that require containment heat removal is maintained at the increased cooling water temperature by imposing more restrictive limits for heat exchanger fouling. Therefore, the temperature averaging approach satisfies the accident and transient analysis assumptions for containment heat removal over time.
The EDGs are considered to rely immediately on the NHS to remove heat from the engine cylinders, combustion inlet air and lubricating oil. As discussed above, the licensee performed testing and engineering analyses to demonstrate that the EDGs remain capable of performing their intended safety function under design-basis conditions (i.e., maximum electrical loading and combustion inlet air temperature and minimum cooling water flow) at cooling water temperatures up to 92 F.
3.3 Condition Two from TSTF-330, Revision 3 When the heat sink is at the proposed maximum allowed value, equipment that is relied upon for accident mitigation, anticipated operational occurrences, or for safe shutdown, will not be adversely affected and are not placed in alarm condition or limited in any way at this higher temperature.
As discussed above, the equipment that is relied upon for accident mitigation, anticipated operational occurrences, or for safe shutdown, remains capable of performing its design-basis function at NHS temperatures up to 92 F. The new limits for equipment degradation that must be imposed to ensure that the affected components would continue to function at the increased cooling water temperature are maintained in the same manner as those that exist for the present cooling water temperature limit.
3.4 Condition Three from TSTF-330, Revision 3 Plant-specific assumptions, such as those that were credited in addressing station blackout and Generic Letter 96-06, have been adjusted (as necessary) to be consistent with the maximum allowed heat sink temperature that is proposed.
The containment air coolers at PBAPS Units 2 and 3 are not credited in the plant safety analysis for post-accident containment heat removal. The licensee performed evaluations in response to GL 96-06 to demonstrate that cooling water systems serving the containment air coolers are not susceptible to waterhammer or overpressurization of isolated piping inside containment following a design-basis accident such that containment integrity could be compromised. These evaluations are not dependent upon the NHS temperature limit. The impact of the increased NHS temperature limit on special events that the plant must be designed to withstand is encompassed by the above evaluations, which demonstrate that the safety-related equipment that relies on the NHS for cooling remains capable of performing its design-basis function at NHS temperatures up to 92 F. Therefore, plant-specific assumptions previously credited in evaluating special events and regulatory issues are not impacted by the increase in the NHS temperature limit.
3.5 Condition Four from TSTF-330, Revision 3 Cooling water that is being discharged from the plant (either during normal plant operation, or during accident conditions) does not affect the heat sink intake water temperature (typical of an infinite heat sink, but the location of the intake and discharge connections, and characteristics of the heat sink can have an impact).
The NHS for PBAPS Units 2 and 3 is the Susquehanna River. The Peach Bottom site is located on the westerly shore of the Conowingo Pond, which is formed in the Susquehanna River by the Conowingo Dam located approximately 9 miles downstream. Holtwood Dam, located approximately 6 miles upstream from the Peach Bottom site, forms the upper boundary of Conowingo Pond. The Muddy Run Pumped Storage Generating Plant, which is owned and operated by the licensee, is located on the easterly shore of the Conowingo Pond approximately 4 miles upstream from the Peach Bottom site. Under normal river flow conditions the PBAPS Units 2 and 3 NHS is considered an infinite heat sink; however, during periods of low river flow, operation of the Muddy Run plant has the potential to reverse the normal downstream flow during the pumping cycle when river flows are below approximately 13,000 cubic feet per second (cfs). A noticeable influence on the PBAPS Units 2 and 3 intake water temperature does not occur until river flow is below 5000 cfs. Observed flows in the Susquehanna River near the site have ranged from a minimum daily average (1964) of 1,400 cfs to a peak (1972) of 972,000 cfs. Average flow is 36,200 cfs.
As a result of the challenge in August 1999 to the NHS temperature limit, the licensee implemented station procedures that limit Muddy Run pumping cycles during periods of high NHS temperature (greater than 85 F) and low river flow (less than 5000 cfs), thus minimizing the impact of Muddy Run operation on PBAPS Units 2 and 3 NHS intake temperature.
3.6 Summary The NRC staff has reviewed the licensees submittal, the Peach Bottom Updated Final Safety Analysis Report, and supporting documentation and agrees that the conditions stated in TSTF-330, Revision 3, for adopting the change to the TSs, have been met by the licensee. In addition, the proposed TS change will not adversely affect plant operation, jeopardize the performance of safety-related equipment, or otherwise compromise public health and safety.
Therefore, the proposed changes to TS 3.7.2, which add temperature averaging requirements for elevated heat sink temperature conditions, are acceptable to the NRC staff.
The licensee also proposed to delete the Actions footnote in TS 3.7.2 that is denoted by an asterisk. This footnote contains a temporary extension to the completion time for Action A that expired on May 31, 2000. Therefore, deletion of this footnote is administrative and is acceptable to the NRC staff.
Since the Bases are not a part of the TSs, the NRC staff reviewed the Bases change only to ensure consistency with the proposed TS change. The NRC staff is not approving the Bases change, but is including the revised Bases pages for completeness.
4.0 STATE CONSULTATION
In accordance with the Commissions regulations, the Pennsylvania State official was notified of the proposed issuance of the amendments. The State official had no comments.
5.0 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 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 (67 FR 34486). 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.
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 Commissions regulations, and (3) 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: John P. Boska Date: July 29, 2002