RS-08-131, Exelon General Company, LLC and Amergen Energy Company, LLC, Nine-Month Response to Generic Letter 2008-01: Difference between revisions

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{{Adams
#REDIRECT [[RS-08-131, General Company, LLC and Amergen Energy Company, LLC, Nine-Month Response to Generic Letter 2008-01]]
| number = ML082880706
| issue date = 10/14/2008
| title = Exelon General Company, LLC and Amergen Energy Company, LLC, Nine-Month Response to Generic Letter 2008-01
| author name = Jury K R
| author affiliation = AmerGen Energy Co, LLC, Exelon Generation Co, LLC, Exelon Nuclear
| addressee name =
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000219, 05000237, 05000249, 05000254, 05000265, 05000277, 05000278, 05000289, 05000352, 05000353, 05000373, 05000374, 05000454, 05000455, 05000456, 05000457, 05000461
| license number = DPR-016, DPR-019, DPR-025, DPR-029, DPR-030, DPR-044, DPR-050, DPR-056, NPF-011, NPF-018, NPF-037, NPF-039, NPF-062, NPF-066, NPF-072, NPF-077, NPF-085
| contact person =
| case reference number = GL-08-001, RS-08-131, TAC MD7797, TAC MD7798, TAC MD7804, TAC MD7805, TAC MD7822, TAC MD7823, TAC MD7839, TAC MD7840, TAC MD7841, TAC MD7842, TAC MD7855, TAC MD7860, TAC MD7861, TAC MD7868, TAC MD7869, TAC MD7888
| document type = Letter type:RS
| page count = 90
| project = TAC:MD7797, TAC:MD7798, TAC:MD7804, TAC:MD7805, TAC:MD7822, TAC:MD7823, TAC:MD7839, TAC:MD7840, TAC:MD7841, TAC:MD7842, TAC:MD7855, TAC:MD7860, TAC:MD7861, TAC:MD7868, TAC:MD7869, TAC:MD7888
| stage = Other
}}
 
=Text=
{{#Wiki_filter:RS-08-131 10 CFR 50.54(f) October 14, 2008 U. S. Nuclear Regulatory Co ATTN: Document Control Desk 11555 Rockville Pike Rockville, MID 20852 Braidwood Station, Units 1 and 2 Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. STN 50-456 and STN 50457 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 N RC Docket No. 50-461 Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237 and 50049 LaSalle County Station, Units 1 and 2 Facility Operating License Nos. NPF-1 1 and NPF-1 8 NRC Docket Nos. 50-373 and 50-374 Limerick Generating Station, Units 1 and 2 Facility Operating License Nos. NPF-39 and NPF-85 NRC Docket Nos. 50-352 and 50-353 Oyster Creek Nuclear Generating Station Facility Operating License No. DPR-16 NRC Docket No. 50-219 Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket N os. 50-277 and 50-278 October 14, 2008 U. S. Nuclear Regulatory Commission Page 2 Quad Cities Nuclear Power Station, Units 1 and 2 Renewed Facility Operating License Nos. DPR-29 and DPR-30 NRC Docket Nos. 50-254 and 50-265 Three Mile Island Nuclear Station, Unit 1 Facility Operating License No. DPR-50 NRC Docket No. 50-289
 
==Subject:==
Nine-Month Response to Generic Letter 2008-01 References
: 1. NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008 2. Letter from K. R. Jury (Exelon Generation Company, LLC/AmerGen Energy Company, LLC) to U. S. NRC, "Three Month Response to Generic Letter 2008-01," dated April 11, 2008 3. Letter from J. Thebe (U. S. NRC) to C. G. Pardee (Exelon Generation Company, LLC/AmerGen Energy Company, LLC), "Braidwood Station, Units 1 and 2; Byron Station, Unit Nos. 1 and 2; Dresden Nuclear Power Station, Units 2 and 3; LaSalle County Station, Units 1 and 2; Limerick Generating Station, Units 1 and 2; Oyster Creek Nuclear Generating Station; Peach Bottom Atomic Power Station, Units 2 and 3; Quad Cities Nuclear Power Station, Units 1 and 2; and Three Mile Island Nuclear Station, Unit 1 - RE: Generic Letter 2008-01, 'Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems,'
Proposed Alternative Course of Action JAC NOS. MD7797, MD7798, MD7804, MD7805, MD7822, MD7823, MD7839, MD7840, MD7841, MD7842, MD7855, MD7860, MD7861, MD7868, MD7869, MD78881" dated September 18, 2008 The NRC issued Generic Letter (GL) 2008-01 (i.e., Reference
: 1) to request that each licensee evaluate the licensing basis, design, testing, and corrective action programs for the Emergency Core Cooling, Decay Heat Removal, and Containment Spray systems, to ensure that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action !~ tnkrn vvhen conditions adverse to quality are identified. 10 CFR 50.54(f) wi information
: The NRC requested each licensee to submit a written response in accordance with e months of the date of the GL to provide the following (summarized) (a) a description of the results of evaluations that were performed pursuant to the requested actions; October 14,2008 U. S. Nuclear Regulatory Co Page 3 (b) a description of all corrective actions that were determined necessary; and the schedule for completion of the corrective actions, and the basis for that schedule. Attachments I through 10 to this letter contain the Exelon Generation Company, LLC (EGC), and AmerGen Energy Company, LLC (AmerGen), nine-month response to NRC GL 2008-01 In summary, EGC/AmerGen has concluded, based on reviews and changes discussed in Attachments 1 through 10, that the GL 2008-01 subject systems are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance. In Reference 2, EGC/AmerGen submitted the three-month response to NRC GL 2008-01 to describe an alternative course of action since the GL 2008-01 requested evaluations would not be fully complete in accordance with the timeframe required by the GL for several of the EGC/AmerGen units. As committed in Reference 2, assessments of inaccessible portions of these systems/functions will be completed during upcoming refueling outages for the affected units, and supplemental responses will be submitted to the NRC documenting completion of walkdowns of inaccessible piping sections. Based on evaluations performed to date, EGC/AmerGen continues to have a reasonable expectation that the GL 2008-01 subject systems are capable of performing their specified safety functions for the reasons discussed in Reference
: 2. The NRC assessment of the three-month response was provided in Reference
: 3. The NRC assessment stated that the EGC/AmerGen Reference 2 submittal did not mention other potential long-term actions that are identified in the GL, such as various industry programs and potential Technical Specification changes that may be necessary to reflect the improved understanding achieved during response to the GL. These items are also addressed within Attachments 1 through 10 of the EGC/AmerGen nine-month response. Regulatory commitments are contained in Attachments 11 through 20 of this letter. Should you have any questions concerning this letter, please contact Mr. Kenneth M. Nicely at (630) 657-2803. I declare under penalty of perjury that the foregoing is true and correct. Executed on the 14th day of October 2008. Keith R. Jury Vice President - Licensing and Regulatory Affairs Exelon Generation Company, LLC AmerGen Energy Company, LLC October 14, 2008 U. S. Nuclear Regulatory Commission Page 4 Attachments
: 1. Generic Letter 2008-01 Nine-Month Response for Braidwood Station 2. Generic Letter 2008-01 Nine-Month Response for Byron Station 3. Generic Letter 2008-01 Nine-Month Response for Clinton Power Station 4. Generic letter 2008-01 Nine-Month Response for Dresden Nuclear Power Station 5. Generic letter 2008-01 Nine-Month Response for LaSalle County Station 6. Generic letter 2008-01 Nine-Month Response for Limerick Generating Station 7. Generic letter 2008-01 Nine-Month Response for Oyster Creek Nuclear Generating Station 8. Generic Letter 2008-01 Nine-Month Response for Peach Bottom Atomic Power Station 9. Generic letter 2008-01 Nine-Month Response for Quad Cities Nuclear Power Station 10. Generic letter 2008-01 Nine-Month Response for Three Mile Island Nuclear Station 11. Regulatory Commitments for Braidwood Station 12. Regulatory Commitments for Byron Station 13. Regulatory Commitments for Clinton Power Station 14. Regulatory Commitments for Dresden Nuclear Power Station 15. Regulatory Commitments for LaSalle County Station 16. Regulatory Commitments for Limerick Generating Sta 17. Regulatory Commitments for Oyster Creek Nuclear Generating Station 18. Regulatory Commitments for Peach Bottom Atomic Power Station 19. Regulatory Commitments for Quad Cities Nuclear Power Station 20. Regulatory Commitments for Three Mile Island Nuclear Station cc: NRC Regional Administrator - Region I NRC Regional Administrator-Region III Senior Resident Inspector - Braidwood Station Senior Resident Inspector - Byron Station Senior Resident Inspector
-- Clinton Power Station Senior Resident Inspector - Dresden Nuclear Power Station Senior Resident Inspector - LaSalle County Station Senior Resident Inspector - Limerick Generating Station Senior Resident Inspector - Oyster Creek Nuclear Generating Station Senior Resident Inspector - Peach Bottom Atomic Power Station Senior Resident Inspector - Quad Cities Nuclear Power Station Senior Resident Inspector - Three Mile Island Nuclear Station ATTACHMENT 1 Generic Letter 2008-01 Nine-Month Response for Braidwood Station This attachment contains the Braidwood Station nine-month response to Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008. The following information is provided in this response: (a) a description of the results of evaluations that were performed pursuant to the requested actions; (b) a description of the corrective actions determined necessary to assure compliance with the quality assurance criteria in Sections III, V, XI, XVI, and XVII of 10 CFR 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," and the licensing bats and operating license with respect to the subject systems; and (c) a statement regarding which corrective actions have been completed, the schedule for the corrective actions not yet complete, and the basis for that schedule. The following Braidwood Station systems were determined to be in the scope of GL 2008-01: " Safety Injection (SI), " Chemical Volume and Control (CV), " Residual Heat (RH), and " Containment Spray (CS). A. LICENSING BASIS EVALUATION The Braidwood Station current licensing basis (CLB) was reviewed with respect to gas accumulation in the SI, CV, RH, and CS systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included the Technical Specifications (TS), TS Bases, Updated Final Safety Analysis Report (UFSAR), Technical Requirements Manual (TRM), responses to NRC generic communications, regulatory commitments, and license conditions. Exelon Generation Company, LLC's (EGC's) review of the CLB for the SI, CV, RH, and CS systems identified no errors associated with implementation of existing licensing basis requirements and commitments. Braidwood TS require verification that Emergency Core Cooling System (ECCS) piping (i.e., SI, CV, and RH) is full of water every 31 days. The TS Bases state that the system will perform properly, injecting its full capacity into the Reactor Coolant System (RCS) upon demand, by maintaining the ing from the ECCS pumps to the RCS full of water. The 31 day frequency takes into consideration the gradual nature of gas accumulation in the ECCS piping and the procedural controls governing system operation. The subject systems and their procedures are in compliance with the Braidwood Station CLB. There are no TS Surveillance Requirements (SRs) that require periodic venting of CS system piping. However, existing station procedures provide controls for CS system filling and venting activities following maintenance that may have voided portions of the system. Page 1 of 7 EGC's evaluation concluded that clarifications or other changes to the TS and TS Bases e warranted to enhance wording relative to gas accumulation issues for the GL subject systems. As a result, the following action is planned to ensure that the TS and TS Bases accurately reflect the technical considerations discussed in GL 2008-01. ATTACHMENT 1 Generic Letter 2008-01 Nine-Month Response for Braidwood Station Potential TS improvements are being developed by the Technical Specifications Task Force (TSTF) with the goal of an NRC-approved TSTF Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. No other changes to Braidwood Station licensing basis documents were identified as a result of evaluations performed in response to GL 2008-01. B. DESIGN EVALUATION The Braidwood Station design bats was reviewed with respect to gas accumulation in the SI, CV, RH, and CS systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included design basis documents, calculations, engineering evaluations, and vendor technical manuals. EGC's review of the design bats for these systems identified no deficiencies associated with implementation (A existing design basis requirements. The systems are designed, tested, and operated in accordance with the TS and EGC's commitments to the applicable design criteria as described in the UFSAR. The design bases and operating procedures appropriately minimize and monitor for gas accumulation. Applicable Gas Volume Acceptanc e Criteria Historically, station procedures associated with filling and venting the GL 2008-01 subject systems have not specified location-specific gas volume acceptance criteria. Rather, the procedures require vent valves to be opened, and a solid stream of water observed while venting. This practice ensues that the amount of air in systems is appropriately minimized to the extent practical, and ensures that systems are maintained in a condition of being sufficiently full following performance of venting surveMances such that the systems can perform their specified safety functions. The impact of the voids on system operability is evaluated on a case-by-case basis, with acceptable void volumes being determined as part of the evaluation. The evaluation process includes consideration of the impact that the void could have on pump operation, water hammer pressure transients, relief valve lifting, check valve closure, potential unbalanced loads, and accident and transient analyses. Industry guidance developed specifically in response to GL 2008-01 is also used. Page 2 of 7 Changes Re sulting from ATTACHMENT I after 2008-01 Nine-Month Response for Braidwood Station No vulnerabilities were identified during the design basis document review. No changes to design basis documents were identified as being needed. Drawing Reviews and System Walkdowns tion diagrams (P&IDs) and isometric drawings were reviewed for the systems within the scope of GL 2008-01 to identify vents and high points. System high points include areas where gas can accumulate in the system, including isolated branch lines, valve bodies, heat exchangers, improperly sloped piping, or locations upstream of components in horizontal lines. As a result of the drawing reviews, EGC identified high points that may be susceptible to gas accumulation. These areas were further evaluated as discussed below. Using the results of the drawing review described above, EGC then performed detailed walkdowns of system piping susceptible to gas accumulation on Unit 2, as well as accessible piping sections susceptible to gas accumulation on Unit 1. The walkdowns were performed to confirm pertinent design details (e.g., the location and orientation of system vents) and as-built configurations (e.g., pipe elevations and slope) to identify areas vulnerable to gas accumulation. Detailed walkdowns of inaccessible piping sections on Unit 1 will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for Braidwood Station. Results of the drawing reviews and system walkdowns were collectively evaluated to identify areas susceptible to gas accumulation that could potentially impact the systems' ability to perform their specified safety functions. These piping locations were further evaluated, and ultrasonic testing (UT) examinations were performed, where appropriate, to confirm whether voids were present. UT examinations were not performed on areas where an assessment concluded they were not necessary (e.g., a determination was made that voiding in the piping location would not impact the system's ability to perform its specified safety function, a determination was made that UT results from one train would be representative of results from a similar train, a determination was made that system flow rates during periodic testing would be adequate to remove voids). No new vent locations were deemed necessary to address vulnerabilities as a result of the evaluation of walkdown and UT examination results. EGC's review identified the need to implement the following corrective action related to the design basis for the systems within the scope of GL 2008-01 for Braidwood Station. The schedule for completing this action was discussed in EGC's three-month response to GL 2008-01 for Braidwood Station. Detailed walkdowns of inaccessible piping sections on Unit 1 will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for Braidwood Station.
ATTACHMENT 1 Generic Letter 2008-01 Nine-Month Response for Braidwood Station Procedure Reviews Associated With Fill and Vent Activities The process for filling and venting the GL 2008-01 subject systems is controlled through station procedures. The procedures have been used multiple times with acceptable results achieved during system restoration. The procedures are adequately segmented to permit appropriate flexibility in restoration of system piping segments based on the performed. These procedures, coupled with surveillance test procedures, provide the means to fill and vent the subject systems as well as purge air and other non-condensable gases from associated piping and components. Procedure OP-AA-10800C "Equipment Return to Service," provides controls to assure the correct performance of activities related to the return to service of plant equipment. The guidance in the procedure is not system-specific
; rather, the procedure provides general requirements associated with returning plant equipment to service and clearance restoration. The procedure was revised as a result of the technical considerations identified in GL 2008-01 to require consideration of UT examinations to ensure proper fill and vent has been achieved. In addition, EGC plans to implement the following action to address enhancements to the procedures that govern fill and vent of the GL 2008-01 subject systems. EGC will revise procedures associated with fill and vent of the GL 2008-01 subject systems to include additional requirements associated with the use of confirmatory UT examinations as pal of system restoration activities as required. These changes are scheduled to be complete by December 31, 2008. In the interim, administrative controls have been implemented to require development of a fill and vent plan that includes the use of confirmatory UT, if appropriate, following system draining or maintenance activities that could introduce gas into the system. The fill and vent procedures were evaluated to determine if the sequence of steps was effective and whether venting of instrument lines was included. EGC determined that the sequence of steps was effective; however, procedure revisions will be implemented to include requirements to verify affected instrument lines have been properly filled. EGC's review identified the need to implement the following corrective action related to the fill and vent procedures for the systems within the scope of GL 2008-01 for Braidwood Station. The schedule for completing this action, and the basis for the schedule, are also provided below. This action is necessary to address gaps that were identified to more accurately reflect the systems' susceptibility to adverse gas accumulation. EGC will revise procedures associated with fill and vent of the GL 2008-01 subject systems to include requirements to verify affected instrument lines have been properly filled. These changes are scheduled to be complete by December 31, 2008. In the interim, administrative controls have been implemented to require development of a fill and vent plan following system draining or maintenance activities that could introduce gas into the system. Page 4 of 7 ATTACHMENT 1 Generic letter 2008-01 Nine-Month Response for Braidwood Station Potential Gas Intrusion Mechanisms Examples of mechanisms that can result in unacceptable gas intrusion include: Poor refill and vent after a return-to-service, Gas coming out of solution over time, and Gas intrusion from an inter-connected system. Ongoing Industry Programs C. TESTING EVALUATION In conjunction with the actions discussed within this attachment, EGC's review of system design and operating practices concluded that the systems are adequately monitored and tested for these potential gas intrusion mechanisms. This review included restoration procedures (i.e., system venting procedures), system design, interfaces with other systems, potential external sources of gas, and operating practices. Ongoing industry programs are planned in the following areas which may impact the conclusions reached during the design evaluation of Braidwood Station relative to gas accumulation, or may result in additional changes to the Braidwood Station design to provide additional margin. a Gas Transport in Pump Suction Piping The Pressurized Water Reactor Owners' Group has initiated testing to provide additional knowledge relative to gas transport in large diameter piping. One program performed testing of gas transport in 6-inch and 8-inch piping. Another program will perform additional testing of gas transport in 4-inch and 12-inch low temperature systems and 4-inch high temperature systems. This program will also integrate the results of the 4-inch, 6-inch, 8-inch, and 12-inch testing. Pump Acceptance Criteria Long-term industry tasks were identified that will provide additional tools to address GL 2008-01 with respect to pump gas void ingestion tolerance limits. Braidwood Station test procedures were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. An industry-recommended template was followed to perform this review, and results have been documented. The CS system is not periodically vented since the design of the system precludes gas accumulation that can affect CS pump operation or result in a water hammer, The CS piping is designed to be empty downstream of the CS pump header isolation valves. This piping is open ended inside containment and is designed for the dynamic loads created then A fills with water. Likewise, the minimum flow recirculation line for the CS Page 5 of 7 recirculation piping downstream of the CS pump discharge test line isolation to Refueling Water Storage Tank (RWST) valves (i.e., S1001A/B) is open ended inside the RWST. In addition, the CS pump suction sources are designed to preclude air intrusion by ensuring an adequate RWST level or by initiating a timely pump suction swap to the recirculation sump, and both features are periodically tested. Periodic venting of the SI, CV, and RH systems is currently performed in accordance with TS SR 3.5.2.3. Braidwoo d Station test procedures that govern the performance of SR 3.5.2.3 were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. These procedures do not specify gas volume acceptance criteria that must be met to satisfy the surveillance. Rather, the procedure requires vent valves to be opened, and a solid stream of water must be observed while venting. This is consistent with EGC's goal of returning systems to a condition of being sufficiently full following performance of venting surveillances, such that the systems can perform their specified safety functions. UT examinations are not currently performed during periodic system testing, with the exception of selected portions of S1 system piping as described in the Braidwood Station TS Bases. However, since performance of UT examinations provide a consistent process to confirm the presence of voids, EGC plans to implement a graded approach for performing periodic LIT examinations of susceptible piping locations. In summary, EGC's review of periodic testing activities identified the need to implement the following corrective action to address improvements to the procedures that govern periodic venting of the SI, CV, and RH systems. EGC will revise periodic venting procedures for the GL 2008-01 subject systems to include enhanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points. These changes are scheduled to be complete by April 30, 2009. This schedule is reasonable based on the fact that the evaluations and LIT examinations performed to date on the GL 2008-01 subject systems have not identified vulnerabilities that challenge the operability of these systems. D. CORRECTIVE ACTIONS EVALUATION ATTACHMENT 1 -01 Nine-Month Response for Braidwood Station EGC's Corrective Action Program is used to document gas intrusion/accumulation issues as potential nonconforming conditions. As part of EGC's Corrective Action issue Reports related to plant equipment are evaluated for potential impact operability and reportability. Therefore, EGC's review concluded that issues involving gas intrusion/accumulation are properly entered, prioritized, and evaluated under the Corrective Action Program.
E. CONCLUSION ATTACHMENT 1 Generic Letter 2008-01 Nine-Month Response for Braidwood Station Based upon the reviews and changes discussed above, EGC has concluded that the GL 2008-01 subject systems are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, opera testing control measures are in place for maintaining this compliance. 
" Safety Injection (SI), " Chemical Volume and Control (CV), " Residual Heat (RH), and " Containment Spray (CS). A. LICENSING BASIS EVALUATION ATTACHMENT 2 etter 2008-01 Nine-Month Response for Byron Stati Page 1 of 7 This attachment contains the Byron Station nine-month response to Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008. The following information is provided in this response: (a) a description of the results of evaluations that were performed pursuant to the requested (b) a description of the corrective actions determined necessary to assure compl the quality assurance criteria in Sections 111, V, XI, XVI, and XVII of 10 CFR 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," and the licensing basis and operating license with respect to the subject systems; and The following Byron Station systems were determined to be in the scope of GL 2008-01: e with (c) a statement regarding which corrective actions have been completed, the schedule for the corrective actions not yet complete, and the basis for that schedule. The Byron Station current licensing basis (CLB) was reviewed with respect to gas accumulation in the SI, CV, RH, and CS systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included the Technical Specifications (TS), TS Bases, Updated Final Safety Analysis Report (UFSAR), Technical Requirements Manual (TRM), responses to NRC generic communications, regulatory commitments, and license conditions. Exelon Generation Company, LLC's (EGC's) review of the CLB for the SI, CV, RH, and CS systems identified no errors associated with implementation of existing licensing basis requirements and commitments. Byron TS require verification that Emergency Core Cooling System (ECCS) piping (i.e., SI, CV, and RN) is full of water every 31 days. The TS Bases state that the system will perform properly, injecting its full capacity into the Reactor Coolant System (RCS) upon demand, by maintaining the piping from the ECCS pumps to the RCS full of water. The 31 day frequency takes into consideration the gradual nature of gas accumulation in the ECCS piping and the procedural controls governing system operation. The subject systems and their procedures are in compliance with the Byron Station CLB. There are no TS Surveillance Requirements (SRs) that require periodic venting of CS system piping. However, existing station procedures provide controls for CS system filling and venting activities following maintenance that may have voided portions of the system.
ATTACHMENT 2 Generic Letter 2008-01 Nine-Month Response for Byron Station EGC's evaluation concluded that clarifications or other changes to the TS and TS Bases be warranted to enhance wording relative to gas accumulation issues for the GL 1 subject systems. As a result, the following action is planned to ensure that the TS and TS Bases accurately reflect the technical considerations discussed in GL 2008-01. Potential TS improvements are being developed by the Technical Specifications Task Force (TSTF) with the goal of an NRC-approved TSTF Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGG is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. No other changes to Byron Station licensing basis documents were identified as a result of evaluations performed in response to GL 2008-01. DESIGN EVALUATION The Byron Station design basis was reviewed with respect to gas accumulation in the SI, CV, RH, and CS systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included design basis documents, calculations, engineering evaluations, and vendor technical manuals. EGC's review of the design basis for these systems identified no deficiencies associated with implementation of existing design basis requirements. The systems are designed, tested, and operated in accordance with the TS and EGC's commitments to the applicable design criteria as described in the UFSAR. The design bases and operating procedures appropriately minimize and monitor for gas accumulation. Applicable Gas Volume Acceptance Criteria Historically, station procedures associated with filling and venting the GL 2008-01 subject systems have not specified location-specific gas volume acceptance criteria. Rather, the procedures require vent valves to be opened, and confirmation that the systems are appropriately vented (e.g., a solid stream of water observed while venting). This practice ensures that the amount of air in systems is appropriately minimized to the extent practical, and ensures that systems are maintained in a condition of hero sufficiently full following performance of venting surveillances such that the systems can perform their specified safety functions. The impact of the voids on system operability is evaluated on a case-by-case basis, with acceptable void volumes being determined as pal of the evaluation. The evaluation process includes consideration of the impact that the void could have on pump operation, water hammer pressure transients, relief valve lifting, check valve closure, Page 2 of 7 Changes Resulting from Design Basis Review ATTACHMENT 2 1 Nine-Month Response for Byron Station potential unbalanced loads, and accident and transient analyses. Industry guidance developed specifically in response to GL 2008-01 is also used. No vulnerabilities were identified during the design basis document review. No changes to design basis documents were identified as being needed. and System Walkdowns Piping & instrumentation diagrams (P&IDs) and isometric drawings were reviewed for the systems within the scope of GL 2008-01 to identify vents and high points. System high points include areas where gas can accumulate in the system, including isolated branch lines, valve bodies, heat exchangers, improperly sloped piping, or locations upstream of components in horizontal lines. As a result of the drawing reviews, EGC identified high points that may be susceptible to gas accumulation. These areas were further evaluated as discussed below. Using the results of the drawing review described above, EGC then performed detailed walkdowns of system piping susceptible to gas accumulation on Unit 1, as well as accessible piping sections susceptible to gas accumulation on Unit 2. The walkdowns were performed to confirm pertinent design details (e.g., the location and orientation of system vents) and as-built configurations
{e.g., pipe elevations and slope) to identify areas vulnerable to gas accumulation. Detailed walkdowns of inaccessible piping sections on Unit 2 will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for Byron Station. Results of the drawing reviews and system walkdowns were collectively evaluated to identify areas susceptible to gas accumulation that could potentially impact the systems' ability to perform their specified safety functions. These piping locations were further evaluated, and ultrasonic testing (UT) examinations were performed, where appropriate, to confirm whether voids were present. UT examinations were not performed on areas where an assessment concluded they were not necessary (e.g., a determination was made that voiding in the piping location would not impact the system's ability to perform its specified safety function, a determination was made that UT results from one train would be representative of results from a similar train, a determination was made that system flow rates during periodic testing would be adequate to remove voids). No new vent locations were deemed necessary to address vulnerabilities as a result of the evaluation of walkdown and UT examination results. EGC's review identified the need to implement the following corrective action related to the design basis for the systems within the scope of GL 2008-01 for Byron Station. The schedule for completing this action was discussed in EGC's three-month response to GL 2008-01 for Byron Station. Detailed walkdowns of inaccessible piping sections on Unit 2 will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for Byron Station. Page 3 of 7 Gener Procedure R s Associa ATTACHMENT 2 008-01 Nine-Month Response for Byron Station ill and Vent Activities ocess for filling and venting the GL 2008-01 subject systems is controlled through on procedures. The procedures have been used multiple times with acceptable results achieved during system restoration. The procedures are adequately segmented to permit appropriate flexibility in restoration of system piping segments based on the enance performed. These procedures, coupled with surveillance test procedures, provide the means to fill and vent the subject systems as well as purge air and other non-condensable gases from associated piping and components. Procedure OP-AA-108-106, "Equipment Return to Service," provides controls to assure the correct performance of activities related to the return to service of plant equipment. The guidance in the procedure is not system-specific
; rather, the procedure provides general requirements associated with returning plant equipment to service and clearance restoration. The procedure was revised as a result of the technical considerations identified in GL 2008-01 to require consideration of UT examinations to ensure proper fill and vent has been achieved. In addition, EGC plans to implement the following action to address enhancements to the procedures that govern fill and vent of the GL 2008-01 subject systems. EGC will revise procedures associated with fill and vent of the GL 2008-01 subject systems to include additional requirements associated with the use of confirmatory UT examinations as part of system restoration activities as required. These changes are scheduled to be complete by December 31, 2008. In the interim, administrative controls have been implemented to require development of a fill and vent plan that includes the use of confirmatory UT, if appropriate, following system draining or maintenance activities that could introduce gas into the system. The fill and vent procedures were evaluated to determine if the sequence of steps was effective and whether venting of instrument lines was included. EGC determined that the sequence of steps was effective; however, procedure revisions will be implemented to include requirements to verify affected instrument lines have been properly filled. EGC's review identified the need to implement the following corrective action related to the fill and vent procedures for the systems within the scope of GL 2008-01 for Byron Station. The schedule for completing this action, and the basis for the schedule, are also provided below. This action is necessary to address gaps that were identified to more accurately reflect the systems' susceptibility to adverse gas accumulation. EGC will revise procedures associated with fill and vent of the GL 2008-01 subject systems to include requirements to verify affected instrument lines have been properly filled. These changes are scheduled to be complete by December 31, 2008. In the interim, administrative controls have been implemented to require development of a fill and vent plan following system draining or maintenance activities that could introduce gas into the system.
ATTACHMENT 2 Generic Letter 2008-01 Nine-Month Response for Byron Station Potential Gas Intrusion Mechanisms Examples of mechanisms that can result in unacceptable gas Poor refill and vent after a return-to-service, Gas coming out of solution over time, and Gas intrusion from an inter-connected system. In conjunction with the actions discussed within this attachment, EGC's review of system design and operating practices concluded that the systems are adequately monitored and tested for these potential gas intrusion mechanisms. This review included restoration procedures (i.e., system venting procedures), system design, interfaces with other systems, potential external sources of gas, and operating practices. Ongoing Industry Programs Ongoing industry programs are planned in the following areas which may impact the conclusions reached during the design evaluation of Byron Station relative to gas accumulation, or may result in additional changes to the Byron Station design to provide additional margin. 0 Gas Transport in Pump Suction Piping The Pressurized Water Reactor Owners' Group has initiated testing to provide additional knowledge relative to gas transport in large diameter piping. One program performed testing of gas transport in 6-inch and 8-inch piping. Another program will perform additional testing of gas transport in 4-inch and 12-inch low temperature systems and 4-inch high temperature systems. This program will also integrate the results of the 4-inch, 6-inch, 8-inch, and 12-inch testing. Pump Acceptance Criteria C. TESTING EVALUATION n include: Long-term industry tasks were identified that will provide additional tools to address GL 2008-01 with respect to pump gas void ingestion tolerance limits. Byron Station test procedures were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. An industry-recommended template was followed to perform this review, and results have been documented. The CS system is not periodically vented since the design of the system precludes gas accumulation that can affect CS pump operation or result in a water hammer. The CS piping is designed to be empty downstream of the CS pump header isolation valves. This piping is open ended inside containment and is designed for the dynamic loads created when A fills with water. Likewise, the minimum flow recirculation line for the CS Page 5 of 7 Gene ATTACHMENT 2 Letter 2008-01 Nine-Month Response for Byron Station ulation piping downstream of the CS pump discharge test line isolation to Refueling Storage Tank (RWST) valves (i.e., 51001A/B) is open ended inside the RWST. In e CS pump suction sources are designed to preclude air intrusion by ensuring an adequate RWST level or by initiating a timely pump suction swap to the recirculation sump, and both features are periodically tested. Periodic venting of the SI, CV, and RH systems is currently performed in accordance with TS SR 3.5.2.3. Byron Station test procedures that govern the performance of SR 3.5.2.3 were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. These procedures do not specify gas volume acceptance criteria that must be met to satisfy the surveillance. Rather, the procedure requires vent valves to be opened, and a solid stream of water must be observed while venting. This is consistent with EGC's goal of returning systems to a condition of being sufficiently full following performance of venting surveillances, such that the systems can perform their specified safety functions. UT examinations are not currently performed during periodic system testing, with the exception of selected portions of S1 system piping as described in the Byron Station TS Bases. However, since performance of UT examinations provide a consistent process to confirm the presence of voids, EGC plans to implement a graded approach for performing periodic UT examinations of susceptible piping locations. In summary, EGC's review of periodic testing activities identified the need to implement the following corrective action to address improvements to the procedures that govern periodic venting of the SI, CV, and RH systems. EGC will revise periodic venting procedures for the GL 2008-01 subject systems to include enhanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points. These changes are scheduled to be complete by April 30, 2009. This schedule is reasonable based on the fact that the evaluations and UT examinations performed to date on the GL 2008-01 subject systems have not identified vulnerabilities that challenge the operability of these systems. CORRECTIVE ACTIONS EVALUATION EGC's Corrective Action Program is used to document gas intrusion/accumulation issues as potential nonconforming conditions. As part of EGC's Corrective Action Program, Issue Reports related to plant equipment are evaluated for potential impact on operability and reportability, Therefore, EGC's review concluded that issues involving gas intrusion/accumulation are properly entered, prioritized, and evaluated under the Corrective Action Program.
Gene CONCLUSION ATTACHMENT 2 2008-01 Nine-Month Response for Byron Station Based upon the reviews and changes discussed above, EGC has concluded that the GL 2008-01 subject systems are in compliance with the current licensing and design bases le regulatory requirements, and that suitable design, operational, and g control measures are in place for maintaining this compliance.
ATTACHMENT 3 Generic Letter 2008-01 Nine-Month Response for Clinton Power Station This attachment contains the Clinton Power Station (CPS) nine-month response to Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008, The following information is provided in this response: (a) a description of the results of evaluations that were performed pursuant to the requested actions; (b) a description of the corrective actions determined necessary to assure compliance with the quality assurance criteria in Sections 111, V, X1, XVI, and XVII of 10 CFR 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," and the licensing bast and operating license with respect to the subject systems; and (c) a statement regarding which corrective actions have been completed, the schedule for the corrective actions not yet complete, and the basis for that schedule. The following CPS systems were determined to be in the scope of GL 2008-01: " High Pressure Core Spray (HPCS), " Low Pressure Core Spray (LPCS), " Residual Heat Removal (RHR) (i.e., Low Pressure Coolant Injection (LPCI), Shutdown Cooling, and Containment Spray modes of RHR). There are related issues that the nuclear industry is currently considering with respect to the overall performance of these systems (i.e., Generic Safety Issue 193, "BWR ECCS Suction Concerns"). Consistent with discussions in SECY 200&108, "Summary of Activities Related to Generic Issues Program," resolution of these related issues would be addressed independent of GL 2008-01 and will not be addressed herein. A. LICENSING BASIS EVALUATION The CPS current licensing basis (CLB) was reviewed with respect to gas accumulation in the HPCS, LPCS, and RHR systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included the Technical Specifications (TS), TS Bases, Updated Safety Analysis Report (USAR), Operational Requirements Manual (ORM), responses to NRC generic communications, regulatory commitments, and license conditions. AmerGen Energy Company, LLC's (AmerGen's) review of the CLB for the HI R systems identified no errors associated with implementation of exis icensing basis requirements and commitments. CPS TS require verification that Emergency Core Cooling System (ECCS) piping (i.e., HPCS, LPCS, and LPCI) is full of water from the pump discharge valve to the injection valve every 31 days. The TS Bases state that maintaining the pump discharge lines of the HPCS system, LPCS system, and LPCI subsystems full of water ensures that the systems will perform properly, injecting their full capacity into the Reactor Coolant System upon demand. The 31 day frequency is based on operating experience, on the procedural controls Page 1 of 6 LPCS, 0 Gener B. DESIGN EVALUATION ATTACHMENT 3 008-01 Nine-Month Response for Clinton Power Station ApHicable Gas Volume Acceptance Weria ion, and on the gradual nature of void buildup gov piping. The subject systems and their procedures are in compliance with the CPS CLB. AmerGen's evaluation concluded that clarifications or other changes to the TS and TS Bases might be warranted to enhance wording relative to gas accumulation issues for the GL 2008-01 subject systems. As a result, the following action is planned to ensure that the TS and TS Bases accurately reflect the technical considerations discussed in GL 2008-01. Potential TS improvements are being developed by the Technical Specifi Task Force (TSTF) with the goal of an NRC-approved TSTF Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. AmerGen is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. AmerGen will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. Page 2 of 6 No other changes to CPS licensing basis documents were identified as a result of evaluations performed in response to GL 2008-01. The CPS design basis was reviewed with respect to gas accumulation in the HPCS, LPCS, and RHR systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included design basis documents, calculations, engineering evaluations, and vendor technical manuals. AmerGen's review of the design basis for these systems identified no deficiencies associated with implementation of existing design basis requirements. The systems are designed, tested, and operated in accordance with the TS and AmerGen's commitments to the applicable design criteria as described in the USAR. The design bases and operating procedures appropriately minimize and monitor for gas accumulation. Historically, station procedures associated with filling and venting the GL 2008-01 subject systems have not specified location-specific gas volume acceptance criteria. Rather, the procedures require vent valves to be opened, and a solid stream of water observed while venting. This practice ensures that the amount of air in systems is appropriately minimized to the extent practical, and ensures that systems are maintained ndition of being sufficiently full following performance of venting surveillances such that the systems can perform their specified safety functions. The impact of the voids on system operability is evaluated on a case-by-case basis, with acceptable void volumes being determined as part of the evaluation. The evaluation process includes consideration of the impact that the void could have on pump ATTACHMENT 3 Generic Letter 2008-0 1 Nine-Month Response for Clinton Power Station operation, water hammer pressure transients, relief valve lifting, check valve closure, potential unbalanced loads, and accident and transient analyses. Industry guidance developed specifically in response to GL 2008-01 is also used. Chanqes Resulting from Design Basis Review No vulnerabilities were identified during the design basis document review. However, as discussed below, new vent locations are planned for installation, and appropriate changes to design basis documents (e.g., drawing revisions) will be made in accordance with the configuration control process. q Reviews and System Walkdowns Piping & instrumentation diagrams (P&IDs) and isometric drawings were reviewed for the systems within the scope of GL 2008-01 to identify vents and high points. System high points include areas where gas can accumulate in the system, including isolated branch lines, valve bodies, heat exchangers, improperly sloped piping, or locations upstream of components in horizontal lines. As a result of the drawing reviews, AmerGen identified high points that may be susceptible to gas accumulation. These areas were further evaluated as discussed below. Using the results of the drawing review described above, AmerGen then performed detailed walkdowns of system piping susceptible to gas accumulation. The walkdowns were performed to confirm pertinent design details (e.g., the location and orientation of system vents) and as-built configurations (e.g., pipe elevations and slope) to identify areas vulnerable to gas accumulation. Results of the drawing reviews and system walkdowns were collectively evaluated to identify areas susceptible to gas accumulation that could potentially impact the systems' ability to perform their specified safety functions. These piping locations were further evaluated, and ultrasonic testing (UT) examinations were performed, where appropriate, to confirm whether voids were present. UT examinations were not performed on areas where an assessment concluded they were not necessary (e.g., a determination was made that voiding in the piping location would not impact the system's ability to perform its specified safety function, a determination was made that UT results from one train would be representative of results from a similar train, a determination was made that system flow rates during periodic testing would be adequate to remove voids). Proper locations for new vents were determined after evaluation of walkdown and UT examination results. AmerGen's review identified the need to implement the following corrective actions related to the design basis for the systems within the scope of GL 2008-01 for CPS. The schedule for completing these actions, and the basis for the schedule, are also provided below. 1 For the HPCS system, one new vent will be installed prior to startup from the next refueling outage. This schedule is reasonable based on the HPCS system being currently operable and plans to implement the modification in order to minimize system unavailability. Page 3 of 6 ATTACHMENT 3 Generic letter 2008-0 1 Nine-Month Response for Clinton Power Station For the RHR system, a modification to add vent and drain holes to an or be installed prior to startup from the next refueling outage. This schedule is reasonable based on the RHR system being currently operable and plans to implement the modification in order to minimize system unavailability. Procedure Reviews Associated With Fill and Vent Activities The process for filling and venting the GL 2008-01 subject systems is controlled through station procedures. The procedures have been used multiple times with acceptable results achieved during system restoration. The procedures are adequately segmented to permit appropriate flexibility in restoration of system piping segments based on the ante performed. These procedures, coupled with surveillance test procedures, provide the means to fill and vent the subject systems as well as purge a& and other non-condensable gases from associated piping and components. Procedure OP-AA-108-106, "Equipment Return to Service," provides controls to assure the correct performance of activities related to the return to service of plant equipment. The guidance in the procedure is not system-specific
; rather, the procedure provides general requirements associated with returning plant equipment to service and clearance restoration. The procedure was revised as a result of the technical considerations identified in GL 2008-01 to require consideration of LIT examinations to ensure proper fill and vent has been achieved. In addition, AmerGen plans to implement the following action to address enhancements to the procedures that govern fill and vent of the GL 2008-01 subject systems. AmerGen will revise procedures CPS 3309.01, "High Pressure Core Spray (HPCS)," CPS 3312.01, "Residual Heat Removal (RHF"" and CPS 3313.01, "Low Pressure Core Spray (LPCS)," to include additional requirements associated with the use of confirmatory LIT examinations as part of system restoration activities as required. These changes will be completed by January 9, 2009. Administrative controls have been implemented to require the use of confirmatory LIT, if appropriate, following system draining or maintenance activities that could introduce gas into the system. The fill and vent procedures were evaluated to determine if the sequence of steps was effective and whether venting of instrument lines was included. AmerGen determined that the sequence of steps was effective; however, procedure revisions will be implemented to include requirements to verify affected instrument lines have been properly filled. AmerGen's review identified the need to implement the following corrective action related to the fill and vent procedures for the systems within the scope of GL 2008-01 for CPS. The schedule for completing this action, and the basis for the schedule, are also provided below. This action is necessary to address gaps that were identified to more accurately reflect the systems' susceptibility to adverse gas accumulation. AmerGen will revise procedures CPS 3309.01, CPS 3312.01, and CPS 3313.01 to include requirements to verify affected instrument lines have been properly filled as part of system restoration activities. These changes will be completed by January 9, Page 4 of 6 ATTACHMENT 3 Generic Letter 2008-0 1 Nine-Month Response for Clinton Power Station 2009. Administrative controls have been implemented to provide guidance to fill and vent following system draining or maintenance activities that could introduce gas into the system. Gas Intrusion Mechanisms Examples of mechanisms that can result in unacceptable gas intrusion include: Poor refill and vent after a return-to-service, Steam intrusion, Gas coming out of solution over time, and Gas intrusion from an inter-connected system. In conjunction with the actions discussed within this attachment, AmerGen's review of system design and operating practices concluded that the systems are adequately monitored and tested for these potential gas intrusion mechanisms. This review included restoration procedures (i.e., system venting procedures), system design, interfaces with other systems, potential external sources of gas, and operating practices. Ongoi ng Industry Programs Ongoing industry programs are planned which any impact the conclusions reached during the design evaluation of CPS relative to gas accumulation, or may result in additional changes to the CPS design to provide additional margin. C. TESTING EVALUATION CPS test procedures were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. An industry-recommended template was followed to perform this review, and results have been documented. Periodic venting of the HPCS, LPCS, and RHR systems is currently performed in accordance with TS Surveillance Requirement (SR) 3.5.1.1. CPS test procedures that govern the performance of SR 3.5.1.1 were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. These procedures do not specify gas volume acceptance criteria that must be met to satisfy the surveillance. Rather, the procedures require vent valves to be opened, and a solid stream of water must be observed while venting. This is ent with AmerGen's goal of returning systems to a condition of being sufficiently following performance of venting surveillances, such that the systems can perform their specified safety functions. UT examinations are not currently performed during periodic system testing. However, since performance of UT examinations provide a consistent process to confirm the Page 5 of 6 ATTACHMENT 3 Generic Letter 2008-0 1 Nine-Month Response for Clinton Power Station presence of voids, AmerGen plans to implement a graded approach for performing periodic LIT examinations of susceptible piping locations. In summary, AmerGen's review of periodic testing activities identified the need to implement the following corrective action to address improvements to the procedures that govern periodic venting of the HPCS, LPCS, and RHR systems. AmerGen will revise periodic venting procedures for the GL 2008-01 subject systems to include enhanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points. These changes are scheduled to be complete by April 30, 2009. This schedule is reasonable based on the fact that the evaluations and LIT examinations performed to date on the GL 2008-01 subject systems have not identified vulnerabilities that challenge the operability of these systems. CORRECTIVE ACTIONS EVALUATION AmerGen's Corrective Action Program is used to document gas intrusion/accumulation issues as potential nonconforming conditions. As part of AmerGen's Corrective Action Program, Issue Reports related to plant equipment are evaluated for potential impact on operability and reportability. Therefore, AmerGen's review concluded that issues involving gas intrusion/accumulation are properly entered, prioritized, and evaluated under the Corrective Action Program. CONCLUSION Based upon the reviews and changes discussed above, AmerGen has concluded that the GL 2008-01 subject systems are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance.
ATTACHMENT 4 Generic Letter 2008-01 Nine-Month Response for Dresden Nuclear Power Station This attachment contains the Dresden Nuclear Power Station (DNPS) nine-month response to is Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008. The following information is provided in this response: (a) a description of the results of evaluations that were performed pursuant to the requested actions; (b) a description of the corrective actions determined necessary to assure compliance with the quality assurance criteria in Sections 111, V, X1, XVI, and XVII of 10 CFR 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," and the licensing basis and operating license with respect to the subject systems; and (c) a statement regarding which corrective actions have been completed, the schedule for the corrective actions not yet complete, and the basis for that schedule. The following DNPS systems were determined to be in the scope of GL 2008-01: " High Pressure Coolant Injection (HPCI), " Low Pressure Coolant Injection (LPCI), including Containment Spray, " Core Spray and ECCS Keepfill (CS), and " Shutdown Cooling (SDC). There are related issues that the nuclear industry is currently considering with respect to the overall performance of these systems (i.e., Generic Safety Issue 193, "BWR ECCS Suction Concerns"). Consistent with discussions in SECY 2008-108, "Summary of Activities Related to Generic Issues Program," resolution of these related issues would be addressed independent of GL 200101 and will not be addressed herein. A. LICENSING BASIS EVALUATION The DNPS current licensing basis (CLB) was reviewed with respect to gas accumulation in the HPCI, LPCI, CS, and SDC systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included the Technical Specifications (TS), TS Bases, Updated Final Safety Analysis Report (UFSAR), Technical Requirements Manual (TRM) and TRM Bases, responses to NRC generic communications, regulatory commitments, and license conditions. The SDC system at DNPS is designed to cool and maintain the reactor water temperature following a normal reactor cooldown using the main condenser. It is not required for mitigation of any event or accident evaluated in the UFSAR, and is not an Emergency Core Cooling System (ECCS). The SDC system is procedurally filled and vented prior to being put into service. The SDCC system is only required to be free of gas accumulation prior to being put into service. Therefore, the system is currently vented prior to use, and there are no CLB requirements for periodic venting of the system. Exelon Generation Company, LLC's (EGC's) review concluded that no changes to the CLE; for the SDC system are needed to address the potential for gas accumulation. Page 1 of 7 Gene ATTACHMENT 4 Letter 2008-01 Nine-Month Response for Dresden Nuclear Power Station he CLB for the HPCI, LPCI, and SDC systems identified no errors associated with implementation of existing licensing basis requirements and commitments. However, EGC's design review identified that for the CS system, vent connections on the north injection line in each unit near the drywell penetrations were installed such that the vents come off the side of the pipe, rather than the top of the pipe. These vents have been modified to correct the design issue. No other vulnerabilities were identified with implementation of existing licensing basis requirements for the CS system. DNPS TS require verification that ECCS piping (i.e., HPCI, LPCI, and CS) is filled water from the pump discharge valve to the injection valve every 31 days. The TS Bases state that maintaining the pump discharge lines of the HPCI system, CS system, and LPCI subsystems full of water ensures that the ECCS will perform properly, injecting its full capacity into the Reactor Coolant System upon demand. The 31 day frequency is based on the gradual nature of void buildup in the ECCS piping, the procedural controls governing system operation, and operating experience. The subject systems and their procedures are in compliance with the DNPS CLB. EGC's evaluation concluded that clarifications or other changes to the TS and TS Bases might be warranted to enhance wording relative to gas accumulation issues for the GL 2008-01 subject systems. As a result, the following action is planned to ensure that the TS and TS Bases accurately reflect the technical considerations discussed in GL 200801. Potential TS improvements are being developed by the Technical Specifications Task Force (TSTF) with the goal of an NRC-approved TSTF Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. No other changes to DNPS licensing basis documents were identified as a result of evaluations performed in response to GL 2008-01. DESIGN EVALUATION The DNPS design basis was reviewed with respect to gas accumulation in the HPCI, LPQ CS, and SDC systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included design basis documents, calculations, engineering evaluations, and vendor technical manuals. EGC's review of the design basis for these systems identified no deficiencies associated with implementation of existing design basis requirements, with the exception of the vents on the CS system that were installed on the side of the pipe, rather than the top of the pipe, as discussed above. Modifications have been installed to correct this Page 2 of 7 ATTACHMENT 4 Generic Letter 2008-01 Nine-Month Response for Dresden Nuclear Power Station vulnerability, and as a result, the systems are designed, tested, and operated in accordance with the TS and EGC's commitments to the applicable design criteria as described in the UFSAR. The design bases and operating procedures appropriately minimize and monitor for gas accumulation. Applicable Gas Volume Acceptance Criteria Historically, station procedures associated with filling and venting the GL 2008-01 subject systems have not specified location-specific gas volume acceptance criteria. Rather, the procedures require vent valves to be opened, and a solid stream of water observed while venting. This practice ensures that the amount of air in systems is appropriately minimized to the extent practical, and ensures that systems are maintained in a condition of being sufficiently full following performance of venting surveillances such that the systems can perform their specified safety functions. The impact of the voids on system operability is evaluated on a case-by-case basis, with acceptable void volumes being determined as part of the evaluation. The evaluation process includes consideration of the impact that the void could have on pump operation, water hammer pressure transients, relief valve lifting, check valve closure, potential unbalanced loads, and accident and transient analyses. Industry guidance developed specifically in response to GL 2008-01 is also used. Changes Resulting from Design Basis Review EGC's design review identified that for the CS system, vent connections on the north injection line in each unit near the drywell penetrations were installed such that the vents come off the side of the pipe, rather than the top of the pipe. These vents have been modified to correct the design issue, and appropriate changes to design basis documents (e.g., drawing revisions) were made in accordance with the configuration control process. No other vulnerabilities were identified during the design basis document review, and no other changes to design bast documents were identified as being needed. Drawin( Reviews and Syste m Walkdowns Piping & instrumentation diagrams (P&Ds) and isometric drawings were reviewed for the systems within the scope of GL 2008-01 to identify vents and high points. System high points include areas where gas can accumulate in the system, including isolated branch lines, valve bodies, heat exchangers, improperly sloped piping, or loco upstream of components in horizontal lines. As a result of the drawing reviews, identified high points that may be susceptible to gas accumulation. These areas were further evaluated as discussed below. Page 3 of 7 Using the results of the drawing review described above, EGC then performed detailed walkdowns of accessible system piping susceptible to gas accumulation on both DNPS units. The walkdowns were performed to confirm pertinent design details (e.g., the location and orientation of system vents) and as-built configurations (e.g., pipe ATTACHMENT 4 Generic Letter 2008-01 Nine-Month Response for Dresden Nuclear Power Sta 3. New vents were added to the 2A and 3B CS systems. Procedure Reviews Associated With Fill and Vent Activities Page 4 of 7 n ns and slope) to identify areas vulnerable to gas accumulation. Detailed ible piping sections will be completed during the next scheduled ling outage for each DNPS unit, as discussed in the three-month response to GL DNPS. the drawing reviews and system walkdowns were collectively evaluated real susceptible to gas accumulation that could potentially impact the systems' ability to perform their specified safety functions. These piping locations were further evaluated, and ultrasonic testing (UT) examinations were performed, where appropriate, to confirm whether voids were present. UT examinations were not performed on areas where an assessment concluded they were not necessary (e.g., a determination was made that voiding in the piping location would not impact the system's ability to perform its specified safety function, a determination was made that system flow rates during periodic testing would be adequate to remove voids). Proper locations for new vents were determined after evaluation of walkdown and LIT examination results. EG(Ts review identified the need 5 implement the following corrective actions related to the design basis for the systems within the scope of GL 2008-01 for DNPS. The schedule for completing the walkdowns of inaccessible piping was discussed in EGC's three-month response to GL 2008-01 for DNPS. Detailed walkdowns of inaccessible piping sections will be completed during the next scheduled refueling outage for each DNPS unit, as discussed in the three-month response to GL 2008-01 for DNPS. For the CS system, EGC has modified the vent connections on the north injection line in each unit near the drywell penetrations such that the vent valves come off the top of the pipe rather than the side of the pipe. The process for filling and venting the GL 2008-01 subject systems is controlled through station procedures. The procedures have been used multiple times with acceptable results achieved during system restoration. The procedures are adequately segmented to permit appropriate flexibility in restoration of system piping segments based on the maintenance performed. These procedures, coupled with surveillance test procedures, provide the means to fill and vent the subject systems as well as purge at and other non-condensable gases from associated piping and components. Procedure OP-AA-108-106, "Equipment Return to Service," provides controls to assure the correct performance of activities related to the return to service of plant equipment. The guidance in the procedure is not system-specific
; rather, the procedure provides general requirements associated with returning plant equipment to service and clearance restoration. The procedure was revised as a result of the technical considerations identified in GL 2008-01 to require consideration of UT examinations to ensure proper fill and vent has been achieved. In addition, EGC plans to implement the ATTACHMENT 4 Generic letter 2008-01 Nine-Month Response for Dresden Nuclear Power Station following action to address enhancements to the procedures that govern fill and vent of the HPCI, LPCI, and CS systems. EGC will revise procedures associated with fill and vent of the HPCI, LPCI, and CS systems to include additional requirements associated with the use of confirmatory UT examinations as part of system restoration activities as required. These changes are scheduled to be complete by October 31, 2008. This schedule is reasonable since no activities we scheduled prior to that time that would require use of the associated procedures. The fill and vent procedures were evaluated to determine if the sequence of steps was effective and whether venting of instrument lines was included. EGC determined that the sequence of sops was effective; however, for the LPCI system, a procedure revision will be implemented to include requirements to verify affected instrument lines have been properly filled. EGC's review identified the need to implement the following corrective actions related to the fill and vent procedures for the systems within the scope of GL 2008-01 for DNPS. The schedule for completing these actions, and the basis for the schedule, are also provided below. These actions are necessary to address gaps that were identified to more accurately reflect the systems' susceptibility to adverse gas accumulation. EGC's review of procedures that govern venting of the SDC system identified there are several vents installed on the system that are not currently used during venting activities. These procedures will be revised to incorporate use of additional vents to enhance venting practices. These changes are scheduled to be complete by October 31, 2008. This schedule is reasonable since no activities are scheduled prior to that time that would require use of the associated procedures. EGC will revise the procedure associated with fill and vent of the LPCI system to include requirements to verify affected instrument lines have been properly filled. This change is scheduled to be complete by October 31, 2008. This schedule is reasonable since no activities are scheduled prior to that time that would require use of the procedure. Potential Gas Intrusion Mechanisms Examples of mechanisms that can result in unacceptable gas intrusion include: Poor refill and vent after a return-to-service, Steam intrusion, Gas coming out of solution over time, and Gas intrusion from an inter-connected system. In conjunction with the actions discussed within this attachment, EGC's review of system design and operating practices concluded that the systems are adequately monitored and tested for these potential gas intrusion mechanisms. This review included Page 5 of 7 ATTACHMENT 4 Generic Letter 2008-01 Nine-Month Response for Dresden Nuclear Power Station restoration procedures (i.e., system venting procedures), system design, interfaces with other systems, potential external sources of gas, and operating practices. Ongoing Industry Programs Ongoing industry programs are planned which may impact the conclusions reached during the design evaluation of DNPS relative to gas accumulation, or may result in additional changes to the DNPS design to provide additional margin. C. TESTING EVALUATION DNPS test procedures were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. An industry-recommended template was followed to perform this review, and results have been documented. The SDC system at DNPS is designed to cool and maintain the reactor water temperature following a normal reactor cooldown using the main condenser. It is not required for mitigation of any event or accident evaluated in the UFSAR, and is not an ECCS system. The SDC system is procedurally filled and vented prior to being put into service. The SDC system is only required to be sufficiently full prior to being placed in service. Therefore, the system is currently vented prior to use, and there is no need for periodic venting of the system. Periodic venting of the HPCI, LPCI, and CS systems is currently performed in accordance with TS Surveillance Requirement (SR) 3.5.1.1. DNPS test procedures that govern the performance of SR 3.5.1.1 were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. These procedures do not specify gas volume acceptance criteria that must be met to satisfy the surveillance. Rather, the procedure requires vent valves to be opened, and a solid stream of water must be observed while venting. This is consistent with EGC's goal of returning systems to a condition of being sufficiently full following performance of venting surveillances, such that the systems can perform their specified safety functions. UT examinations are not currently performed during periodic system testing. However, since performance of LIT examinations provide a consistent process to confirm the presence of voids, EGC plans to implement a graded approach for performing periodic UT examinations of susceptible piping locations. EGC will revise periodic venting surveillances for the HPCI, LPCI, and CS systems to include enhanced acceptance criteria and requirements to perform UTs on a graded Page 6 of 7 In summary, EGC's review of periodic testing activities identified the need to implement the following corrective action to address improvements to the procedures that govern periodic venting of the HPCI, LPCI, and CS systems.
Gene approach as part of venting verifications of accessible high points. These changes are scheduled to be complete by April 30, 2009. This schedule is reasonable based on the fact that the evaluations and UT examinations performed to date on the GL 2008-01 subject systems have not identified vulnerabilities that challenge the ility of these systems, except for the CS vents mounted on the sides of the discussed above. CORRECTIVE ACTIONS EVALUATION EGC's Corrective Action Program is used to document gas intrusion/accumulation issues as potential nonconforming conditions. As part of EGC's Corrective Action Program, Issue Reports related to plant equipment are evaluated for potential impact on operability and reportability. Therefore, EGC's review concluded that issues involving gas intrusion/accumulation are properly entered, prioritized, and evaluated under the Corrective Action Program. CONCLUSION ATTACHMENT 4 r 2008-01 Nine-Month Response for Dresden Nuclear Power Station Based upon the reviews and changes discussed above, EGC has concluded that the GL 2008-01 subject systems are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance.
ATTACHMENT 5 Generic Letter 2008-01 Nine-Month Response for LaSalle County Station This attachment contains the LaSalle County Station (LSCS) nine-month response to Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008. The following information is provided in this response: (a) a description of the results of evaluations that were performed pursuant to the requested actions; (b) a description of the corrective actions determined necessary to assure compliance with the quality assurance criteria in Sections III, V, X1, XVI, and XVII of 10 CFR 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," and the licensing basis and operating license with respect to the subject systems; and (c) a statement regarding which corrective actions have been completed, the schedule for the corrective actions not yet complete, and the basis for that schedule. The following LSCS systems were determi High Pressure Core Spray (HPCS), Low Pressure Core Spray (LPCS), and Residual Heat Removal (RHR) (i.e., Suppression Pool Cooling, Low Pressure Coolant Injection (LPCI), Shutdown Cooling, Drywall Spray, and Suppression Pool Spray modes of RHR). There are related issues that the nuclear industry is currently considering with respect to the overall performance of these systems (i.e., Generic Safety Issue 193, "BWR ECCS Suction Concerns"). Consistent with discussions in SECY 200&108, "Summary of Activities Related to Generic Issues Program," resolution of these related issues would be addressed independent of GL 2008-01 and will not be addressed herein. LICENSING BASIS EVALUATION The LSCS current licensing basis (CLB) was reviewed with respect to gas accumulation in the HPCS, LPCS, and RHR systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included the Technical Specifications (TS), TS Bases, Updated Final Safety Analysis Report (UFSAR), Technical Requirements Manual (TRM) and TRM Bases, responses to NRC generic communications, regulatory commitments, and license conditions. Exelon Generation Company, LLC's {EEC's) review of the CLB for the HPCS, LPCS, and RHR systems identified no errors associated with implementation of existing nsing basis requirements and commitments. LSCS TS require verification that envy Core Cooling System (ECCS) piping (i.e., HPCS, LPCS, and LPCI) is filled with water from the pump discharge valve to the injection valve every 31 days. The TS Bases state that maintaining the pump discharge lines of the HPCS system, LPCS system, and LPCI subsystems full of water ensures that the systems will perform properly, injecting their full capacity into the Reactor Coolant System (RCS) upon d to be in the scope of GL 2008-01: Page 1 of 7 ATTACHMENT 5 Generic Letter 2008-01 Nine-Month Response for LaSalle County Station demand. The 31 day frequency is based on operating experience, on the procedural controls governing system operation, and on the gradual nature of void buildup in the ECCS piping. The subject systems and their procedures are in compliance with the LSCS CLB. EGC's evaluation concluded that clarifications or other changes to the TS and TS Bases to enhance wording relative to gas accumulation issues for the GL -01 subject systems. As a result, the following action is planned to ensure that the TS and TS Bases accurately reflect the technical considerations discussed in GL 2008-01. Potential TS improvements are being developed by the Technical Specifications Task Force (TSTF) with the goal of an NRC-approved TSTF Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation agement Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. DESIGN EVALUATION No other changes to LSCS licensing basis documents were identified as a result of evaluations performed in response to GL 2008-01. The LSCS design basis was reviewed with respect to gas accumulation in the HPCS, LPCS, and RHR systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included design basis documents, calculations, engineering evaluations, and vendor technical manuals. EGC's review of the design basis for these systems identified no deficiencies associated with implementation (A existing design basis requirements. The systems are designed, tested, and operated in accordance with the TS and EGC's commitments to the applicable design criteria as described in the UFSAR. The design bases and operating procedures appropriately minimize and monitor for gas accumulation. Applicable Gas Volume Acceptance Criteria Historically, station procedures associated with filling and venting the GL 2008-01 subject systems have not specified location-specific gas volume acceptance criteria. Rather, the procedures require vent valves to be opened, and a solid stream of water observed while venting. This practice ensures that the amount of air in systems is appropriately minimized to the extent practical, and ensures that systems are mai in a condition of being sufficiently f u ll following performance of venting surveillances such that the systems can perform their specified safety functions. Page 2 of 7 d ATTACHMENT 5 Generic Letter 2008-01 Nine-Month Response for LaSalle County Station voids on system operability is evaluated on a case-by-case basis, with void volumes being determined as part of the evaluation. The evaluation lodes consideration of the impact that the void could have on pump operation, water hammer pressure transients, relief valve lifting, check valve closure, potential unbalanced loads, and accident and transient analyses. Industry guidance developed specifically in response to GL 2008-01 is also used. Design Bats Review The I&CS system is connected to the RCS through the injection line, which includes a normally closed injection valve and injection check valve. RCS leakage past both these valves would result in actuation of a pressure switch, actuation of a control room annunciator, and entry into the associated alarm response procedure. This procedure was revised to provide direction for identifying a temperature increase that could lead to saturated conditions within the piping, which could result in void formation. The LPCS system is connected to the RCS through the injection line, which includes a normally closed injection valve and injection check valve. RCS leakage past both these valves would result in actuation of a pressure switch, actuation of a control room annunciator, and entry into the associated alarm response procedure. This procedure was revised to provide direction for identifying a temperature increase that could lead to saturated conditions within the piping, which could result in void formation. 3. The RHR system is connected to the RCS through several different lines, each containing valves that are normally closed. RCS leakage past these valves could potentially lead to saturated conditions within the piping, which could result in void formation. This would result in actuation of pressure switches and annunciation in the control room. Annunciator response procedures were revised to provide direction for identifying a temperature increase that could lead to saturated conditions within the piping, which could result in void formation. n-q Reviews and System Walkdowns Piping & instrumentation diagrams (P&IDs) and isometric drawings were reviewed for the systems within the scope of (GL 2008-01 to identify vents and high points. System high points include areas where gas can accumulate in the system, including isolated branch lines, valve bodies, heat exchangers, improperly sloped piping, or locations upstream of components in horizontal lines. As a result of the drawing reviews, EGC identified high points that may be susceptible to gas accumulation. These areas were further evaluated as discussed below. Using the results of the drawing review described above, EGC then performed detailed walkdowns of accessible system piping susceptible to gas accumulation on both LSCS units. The walkdowns were performed to confirm pertinent design details (e.g., the location and orientation of system vents) and as-built configurations (e.g., pipe elevations and slope) to identify areas vulnerable to gas accumulation. Detailed Page 3 of 7 ATTACHMENT 5 Generic Letter 2008-01 Nine-Month Response for LaSalle County Station walkdowns of inaccessible piping sections will be completed during the next scheduled refueling outage for each LSCS unit, as discussed in the three-month response to GL 2008-01 for LSCS. Results of the drawing reviews and system walkdowns were collectively evaluated to identify areas susceptible to gas accumulation that could potentially impact the systems' ability to perform their specified safety functions. These piping locations were further evaluated, and ultrasonic testing (UT) examinations were performed, where appropriate, to confirm whether voids were present. UT examinations were not performed on areas where an assessment concluded they were not necessary (e.g., a determination was made that voiding in the piping location would not impact the system's ability to perform its specified safety function, a determination was made that system flow rates during periodic testing would be adequate to remove voids). No new vent locations were deemed necessary to address vulnerabilities as a result of the evaluation of walkdown and UT examination results. EGC's review identified the need to implement the following corrective action related to the design basis for the systems within the scope of GL 2008-01 for LSCS. The schedule for completing this action was discussed in EGC's three-month response to GL 2008-01 for LSCS. Detailed walkdowns of inaccessible piping sections will be completed during the next scheduled refueling outage for each LSCS unit, as discussed in the three-month response to GL 2008-01 for LSCS, Procedure Reviews Associated With Fill and Vent Activities The process for filling and venting the GL 2008-01 subject systems is controlled through station procedures. The procedures have been used multiple times with acceptable results achieved during system restoration. The procedures are adequately segmented to permit appropriate flexibility in restoration of system piping segments based on the maintenance performed. These procedures, coupled with surveillance test procedures, provide the means to fill and vent the subject systems as wall as purge air and other non-condensable gases from associated piping and components. Procedure OP-AA-10810Q "Equipment Return to Service," provides controls to assure the correct performance of activities related to the return to service of plant equipment. The guidance in the procedure is not system-specific
; rather, the procedure provides general requirements associated with returning plant equipment to service and clearance restoration. The procedure was revised as a result of the technical considerations identified in GL 2008-01 to require consideration of LIT examinations to ensure proper fill and vent has been achieved. In addition, EGC has implemented the following action to address enhancements to the procedures that govern fill and vent of the GL 2008-01 subject systems. EGC has revised procedures associated with fill and vent of the GL 2008-01 subject systems to include additional requirements associated with the use of confirmatory UT examinations as part of system restoration activities as required. Page 4 of 7 ATTACHMENT 5 Generic Letter 2008-01 Nine-Month Response for LaSalle County Station The fill and vent procedures were evaluated to determine if the sequence of steps was effective and whether venting of instrument lines was included. EGC determined that the sequence of sops was effective; however, a procedure revision for the HPCS system was implemented to include requirements to verify affected instrument lines have been properly filled. EGCs evaluation determined that procedures for the LPCS and RHR systems provide appropriate guidance for instrument lines. EGC's review identified the need to implement the following corrective actions related to the fill and vent procedures for the systems within the scope of GL 2008-01 for LSCS. These actions are necessary to address gaps that were identified to more accurately reflect the systems' susceptibility to adverse gas accumulation. 2. EGC has revised the procedure associated with fill and vent of the LPCS system to add a requirement to use valves 1(2)E21 -F027/F323 and 1(2)E21 -F029/F324 during system venting. 3. EGC has revised the procedure associated with fill and vent of the HPCS system to add a requirement to use valves 1(2)E22-F026, 1(2)E22-F012, and 1(2)E22-FO23 during system venting. has revised the procedure associated with fill and vent of the HPCS system to include requirements to verify affected instrument lines have been properly filled. EGC has revised the procedure associated with fill and vent of the RHR system to add a requirement to use vent valves that were previously not used. Potential Gas Intrusion Mechanisms Examples of mechanisms that can result in unacceptable gas intrusion include: " Poor refill and vent after a return-to-service, " Steam intrusion, " Gas coming out of solution over time, and " Gas intrusion from an inter-connected system. In conjunction with the actions discussed within this attachment, EGC's review of system design and operating practices concluded that the systems are adequately monitored and tested for these potential gas intrusion mechanisms. This review included procedures (i.e., system venting procedures), system design, interfaces with systems, potential external sources of gas, and operating practices. Ind ustry Programs Page 5 of 7 Ongoing industry programs are planned which may impact the conclusions reached during the design evaluation of LSCS relative to gas accumulation, or may result in additional changes to the LSCS design to provide additional margin.
C. TESTING EVALUATION ATTACHMENT 5 Generic Letter 2008-01 Nine-Month Response for LaSalle County Station LSCS test procedures were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. An industry-recommended template was followed to perform this review, and results have been documented. Periodic venting of the HPCS, LPCS, and RHR systems is currently performed in accordance with TS Surveillance Requirements (SRs) 3.5.1.1 and 3.5.2.3. LSCS test procedures that govern the performance of SRs 3.5.1.1 and 3.5.2.3 were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. These procedures do not specify gas volume acceptance criteria that must be met to satisfy the surveillance. Rather, the procedure requires vent valves to be opened, and a solid stream of water must be observed while venting. This is consistent with EGC's goal of returning systems to a condition of being sufficiently full following performance of venting surveillances, such that the systems can perform their specified safety functions. LIT examinations are not currently performed during periodic system testing. However, since performance of UT examinations provide a consistent process to confirm the presence of voids, EGC plans to implement a graded approach for performing periodic LIT examinations of susceptible piping locations. In summary, EGC's review of periodic testing activities identified the need to implement the following corrective action to address improvements to the procedures that govern periodic venting of the HPCS, LPCS, and RHR systems. EGC will revise periodic venting procedures for the GL 2008-01 subject systems to include enhanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of acceptable high points. These changes are scheduled to be complete by April 30, 2009. This schedule is reasonable based on the fact that the evaluations and LIT examinations performed to date on the GL 2008-01 subject systems have not identified vulnerabilities that challenge the operability of these systems. CORRECTIVE ACTIONS EVALUATION EGC's Corrective Action Program is used to document gas intrusionfaccumulation ial nonconforming conditions. As part of EGC's Corrective Action Program, Issue Reports related to plant equipment are evaluated for potential impact on operability and reportability. Therefore, EGC's review concluded that issues involving gas intrusion/accumulation are properly entered, prioritized, and evaluated under the Corrective Action Program.
CONCLUSION ATTACHMENT 5 Letter 2008-01 Nine-Month Response for LaSalle County Station ews and changes discussed above, EGC has concluded that the GL easing and design bases perational, and this compliance. Based upon the rev 2008-01 subject systems are in compliance and applicable regulatory requirements, and that sui testing control measures are in place for maintai ATTACHMENT 6 Generic Letter 2008-01 Nine-Month Response for Limerick Generating Station This attachment contains the Limerick Generation Station (LGS) nine-month response to Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008. The following information is provided in this response: (a) a description of the results of evaluations that were performed pursuant to the requested actions; (b) a description of the corrective actions determined necessary to assure compliance with the quality assurance criteria in Sections III, V, XI, XVI, and XVII of 10 CFR 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," and the licensing basis and operating license with respect to the subject systems; and (c) a statement regarding which corrective actions have been completed, the schedule for the corrective actions not yet complete, and the basis for that schedule. The following LGS systems were determined to be in the scope of GL 2008-01: " High Pressure Coolant Injection (HPCI), " Core Spray (CS), and " Residual Heat Removal (RHR) (i.e., Suppression Pool Cooling, Shutdown Cooling, Alternate Decay Heat Removal, Low Pressure Coolant Injection (LPCI), and Containment Spray modes of RHR). There are related issues that the nuclear industry is currently considering with respect to the overall performance of these systems (i.e., Generic Safety Issue 193, "BWR ECCS Suction Concerns"). Consistent with discussions in SECY 2008-108, "Summary of Activities Related to Generic Issues Program," resolution of these related issues would be addressed independent of GL 2008-01 and will not be addressed herein. LICENSING BASIS EVALUATION The LGS current licensing basis (CLB) was reviewed with respect to gas accumulation in the HPCI, CS, and RHR systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included the Technical Specifications (TS), TS Bases, Updated Final Safety Analysis Report (UFSAR), Technical Requirements Manual (TRM) and TRM Bases, responses to NRC generic communications, regulatory commitments, and license conditions. Exelon Generation Company, LLCs {EEC's} review of the CLB for the HPCI, CS, and RHR systems identified no errors associated with implementation of existing licensing basis requirements and commitments. LGS TS require verification that Emergency Core Cooling System (ECCS) piping (i.e., HPCK CS, and LPCI) is full from the pump discharge valve to the system isolation valve (i.e., injection valve) in accordance with the Surveillance Frequency Control Program. The TS Bases state that the pump discharge piping is maintained full to prevent water hammer damage and to provide cooling at the Page 1 of 6 ATTACHMENT 6 Generic Letter 2008-01 Nine-Month Response for Limerick Generating Station earliest moment. The subject systems and their procedures are in compliance with the LGS CLB. EGC's evaluation concluded that clarifications or other changes to the TS and TS Bases might be warranted to enhance wording relative to gas accumulation issues for the GL 2008-01 subject systems. As a result, the following action is planned to ensure that the TS and TS Bases accurately reflect the technical considerations discussed in GL 2008-01. Potential TS improvements are being developed by the Technical Specifications Task Force (TSTF) with the goal of an NRC-approved TSTF Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGG is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained 4 the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. No other changes to LGS licensing basis documents were identified as a result of evaluations performed in response to GL 2008-01. B. DESIGN EVALUATION The LGS design basis was reviewed with respect to gas accumulation in the HPCI, CS, and RHR systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included design basis documents, calculations, engineering evaluations, and vendor technical manuals. EGC's review of the design basis for these systems identified no deficiencies associated with implementation of existing design basis requirements. The systems are designed, tested, and operated in accordance with the TS and EGC's commitments to the applicable design criteria as described in the UFSAR. The design bases and operating procedures appropriately minimize and monitor for gas accumulation. App licable Gas Volume Acceptance Criteria Historically, station procedures associated with filling and venting the GL 2008-01 subject systems have not specified location-specific gas volume acceptance criteria. Rather, the procedures require vent valves to be opened, and a solid stream of water observed while venting. This practice ensures that the amount of air in systems is appropriately minimized to the extent practical, and ensures that systems are maintained in a condition of being sufficiently full following performance of venting surveillances such that the systems can perform their specified safety functions. The impact of the voids on system operability is evaluated on a case-by-case basis, with acceptable void volumes being determined as pal of the evaluation. The evaluation process includes consideration of the impact that the void could have on pump Page 2 of 6 ATTACHMENT 6 Generic Letter 2008-01 Nine-Month Response for Limerick Generat operation, water hammer pressure transients, relief valve lifting, check valve closure, potential unbalanced loads, and accident and transient analyses. Industry guidance developed specifically in response to GL 2008-01 is also used. Drawing Reviews and System Walkdowns ion No vulnerabilities were identified during the design basis document review. However, as discussed below, new vent locations are planned for installation, and appropriate changes to design basis documents (e.g., drawing revisions) will be made in accordance with the configuration control process. Piping & instrumentation diagrams (P&IDs) and isometric drawings were reviewed for the systems within the scope of GL 2008-01 to identify vents and high points. System high points include areas where gas can accumulate in the system, including isolated branch lines, valve bodies, heat exchangers, improperly sloped piping, or locations upstream of components in horizontal lines. As a result of the drawing reviews, EGG identified high points that may be susceptible to gas accumulation. These areas were further evaluated as discussed below. Using the results of the drawing review described above, EGC then performed detailed walkdowns of system piping susceptible to gas accumulation on Unit 1, as well as accessible piping sections susceptible to gas accumulation on Unit 2. The walkdowns were performed to confirm pertinent design details (e.g., the location and orientation of system vents) and as-built configurations (e.g., pipe elevations and slope) to identify areas vulnerable to gas accumulation. Detailed walkdowns of inaccessible piping sections on Unit 2 will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for LGS. Results of the drawing reviews and system walkdowns were collectively evaluated to identify areas susceptible to gas accumulation that could potentially impact the systems' ability to perform their specified safety functions. These piping locations were further evaluated, and ultrasonic testing (UT) examinations were performed, where appropriate, to confirm whether voids were present. UT examinations were not performed on areas where an assessment concluded they were not necessary (e.g., a determination was made that voiding in the piping location would not impact the system's ability to perform specified safety function, a determination was made that LIT results from one train would be representative of results from a similar train, a determination was made that system flow rates during periodic testing would be adequate to remove voids). Proper locations for new vents were determined after evaluation of walkdown and UT examination results. EGCs review identified the need to implement the following corrective actions related to the design basis for the systems within the scope of GL 2008-01 for LGS. The schedule for completing the remaining corrective actions, and the basis for the schedule, are also provided below. Page 3 of 6 ATTACHMENT 6 Generic Letter 2008-01 Nine-Month Response for Limerick Generating Station owns of inaccessible piping sections on Unit 2 will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for LGS. The schedule for completing this action was discussed in EGC's three-month response to GL 2008-01 for LGS. 2. For the HPCI system, three new vents were installed on each LGS unit. In addition, three additional new vents will be installed on each LGS unit prior to startup from the next scheduled refueling outage for each unit. Voids that were discovered in the HPCI system have been evaluated and determined to not adversely impact the ability of the HPCI system to perform its specified safety functions. 3. For the CS system, six new vents will be installed on each LGS unit prior to startup from the next scheduled refueling outage for each unit. Voids that were discovered in the CS system have been evaluated and determined to not adversely impact the ability of the CS system to perform its specified safety functions. For the RHR system, one new vent will be installed on Unit 1, and two new vents will be installed on Unit 2, prior to startup from the next scheduled refueling outage for each unit. Voids that were discovered in the RHR system have been evaluated and determined to not adversely impact the ability of the RHR system to perform its specified safety functions. Procedure Reviews Associated With Fill and Vent Activities The process for filling and venting the GL 2008-01 subject systems is controlled through station procedures. The procedures have been used multiple times with acceptable results achieved during system restoration. The procedures are adequately segmented to permit appropriate flexibility in restoration of system piping segments based on the maintenance performed. These procedures, coupled with surveillance test procedures, provide the means to fill and vent the subject systems as well as purge air and other non-condensable gases from associated piping and components. Procedure OP-AA-108-106, "Equipment Return to Service," provides controls to assure the correct performance of activities related to the return to service of plant equipment. The guidance in the procedure is not system-specific
; rather, the procedure provides general requirements associated with returning plant equipment to service and clearance restoration. The procedure was revised as a result of the technical identified in GL 2008-01 to require consideration of UT examinations to ensure proper fill and vent has been achieved. In addition, LGS procedures for the GL 2008-01 subject systems include requirements for the use of post fill and vent confirmatory UT verifications during system restoration activities as required. The fill and vent procedures were evaluated to determine if the sequence of steps was effective and whether venting of instrument lines was included. EGC determined that the sequence of sops was effective; however, a procedure revision for the CS system Page 4 of 6 ATTACHMENT 6 Generic Letter 2008-01 Nine-Month Response for Limerick Generating Station plemented to include requirements to verify affected instrument lines have been properly filled. EGC's review identified the need to implement the following corrective action related to the fill and vent procedures for the systems within the scope of GL 2008-01 for LGS. This action is necessary to address gaps that were identified to more accurately reflect the systems' susceptibility to adverse gas accumulation. 0 has revised procedure S52.1.A, "Core Spray Setup for Service Operation," to nclude requirements to verify affected instrument lines have been properly filled. Ongoing Industry Programs C. TESTING EVALUATION Mechanisms Poor refill and vent after a return-to-service, Steam intrusion, Gas coming out of solution over time, and Gas intrusion from an inter-connected system. Potential Gas Intrus Examples of mechanisms that can result in unacceptable gas intrusion include: In conjunction with the actions discussed within this attachment, EGC's review of system design and operating practices concluded that the systems are adequately monitored and tested for these potential gas intrusion mechanisms. This review included restoration procedures (i.e., system venting procedures), system design, interfaces with other systems, potential external sources of gas, and operating practices. Ongoing industry programs are planned which may impact the conclusions reached during the design evaluation of LGS relative to gas accumulation, or may result in additional changes to the LGS design to provide additional margin. LGS test procedures were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. An industry-recommended template was followed to perform this review, and results have been documented. Periodic venting of the HPCI, CS, and RHR systems is currently perform accordance with TS Surveillance Requirement (SR) 4.5.1.a.l.a. LGS test procedures that govern the performance of SR 4.5.1.a.l.a were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. These procedures do not specify gas volume acceptance criteria that must be met to satisfy the surveillance. Rather, the procedure requires vent valves to be opened, and a solid stream of water must be observed while venting. This is Page 5 of 6 ATTACHMENT 6 Generic Letter 2008-01 Nine-Month Response for Limerick Generat consistent with EGC's goal of returning systems to a condition of being sufficiently full following performance of venting surveillances, such that the systems can perform their specified safety functions. dons are not currently performed doing erformance of UT examinations provi presence of voids, EGC plans to implement a gra LIT examinations of susceptible piping locations. D. CORRECTIVE ACTIONS EVALUATION E. CONCLUSION In summary, EGC's review of periodic testing activities identified the need to implement the following corrective action to address improvements to the procedures that govern periodic venting of the HPCI, RHR, and CS systems. EGC will revise periodic venting procedures for the GL 2008-01 subject systems to include enhanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points. These changes are scheduled to be complete by April 30, 2009. This schedule is reasonable based on the fact that the evaluations and LIT examinations performed to date on the GL 2008-01 subject systems have not identified vulnerabilities that challenge the operability of these systems. In addition, surge chambers for the systems will alarm in the Main Control Room on low system water level. These surge chambers are located at the high points of the systems and are physically higher than the main system piping, ensuring gas that accumulates at the high points is detected in a timely manner. EGC's Corrective Action Program is used to document gas intrusion/accumulation issues as potential nonconforming conditions. As part of EGC's Corrective Action Program, Issue Reports related to plant equipment are evaluated for potential impact on operability and reportability. Therefore, EGC's review concluded that issues involving gas intrusion/accumulation are properly entered, prioritized, and evaluated under the Corrective Action Program. Based upon the reviews and changes discussed above, EGC has concluded that the GL 2008-01 subject systems are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance. anon is system testing. However, ess to confirm the performing periodic ATTACHMENT 7 attar 2008-01 Nine-Month Response for Oyster Creek Nuclear Generating Station This attachment contains the Oyster Creek Nuclear Generating Station (OCNGS) nine-month response to Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008. The following information is provided in this response: (a) a description of the results of evaluations that were performed pursuant to the requested (b) a description of the corrective actions determined necessary to assure compliance the quality assurance criteria in Sections 111, V, XI, XVI, and XVII of 10 CFR 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," and the licensing basis and operating license with respect to the subject systems; and (c) a statement regarding which corrective actions have been completed, the schedule for the corrective actions not yet complete, and the basis for that schedule. The following OCNGS systems w Core Spray (CS), Isolation Condenser System (ICS), Containment Spray, and Shutdown Cooling (SDC). ermined to be the scope of GL 2008-01: There are related issues that the nuclear industry is currently considering with respect to the overall performance of these systems (i.e., Generic Safety Issue 193, "BWR ECCS Suction Concerns"). Consistent with discussions in SECY 2008-108, "Summary of Activities Related to Generic Issues Program," resolution of these related issues would be addressed independent of GL 200&01 and will not be addressed herein. LICENSING BASIS EVALUATION The OCNGS current licensing basis (CLB) was reviewed with respect to gas accumulation in the CS, ICS, Containment Spray, and SDC systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included the Technical Specifications (TS), TS Bases, Updated Final Safety Analyst Report (UFSAR), responses to NRC generic communications, regulatory commitments, and license conditions. The CS system includes a Core Spray Filling System to keep the CS system piping filled with water. A water leg is maintained in the piping to preclude water hammer when the system goes into operation. Fill pumps take suction from the torus and discharge torus water to the main piping, which overflows through the pump minimum flow recirculation piping back to the torus. This assures that the main piping remains full since the recirculation lines are located at a higher elevation than the main piping. The CS discharge piping is kept full by use of a continuously operating keep-fill pump. Fill pump operation is verified daily by operator rounds and an alarm for low discharge line pressure is provided in the control room. Page 1 of 7 ATTACHMENT 7 Generic Letter 2008-01 Nine-Month Response for Oyster Creek Nuclear Genera Station The ICS is one of three Emergency Core Cooling Systems (ECCS) at OCNGS. The ICS is a standby, high-pressure system for removal of fission product decay heat when the reactor vessel is isolated from the main condenser. The system prevents overheating of the reactor fuel, controls the reactor pressure rise, and limits the loss of reactor coolant through the relief valves. The ICS operates by natural circulation without the need for driving power other than the electrical system used to place the ICS in operation. During ICS operation, steam from the reactor vessel condenses at the tube bundles as heat is transferred through the tubes into the shell side of the ICS. Condensate flows by natural circulation back into recirculation loops A and E through the condensate return lines. The valves in the steam inlet lines are normally open so that the tube bundles are at reactor pressure. Only the DC motor-operated condensate isolation valves are normally closed. The high points in the steam supply lines to each loop are vented continuously to the main turbine steam header downstream of the main steam isolation valves when the plant is operating and the ICS is in standby. This is done to remove noncondensable gases from the reactor steam, which would otherwise collect at these high points in the system. Therefore, the ICS is not vulnerable to gas accumulation related transients due to the system's design. The Containment Spray system consists of two redundant loops, which deliver water from the suppression pool to the spray headers in the drywell and torus. Both loops share a common suction header from the suppression pool and a common spray header in the torus air space. A recirculation line, which returns to the torus, permits operation of the system for controlling the temperature of the suppression pool during normal and abnormal plant operation. During standby, the Containment Spray system piping drains back to the torus after securing pumps, down to a level equal to the torus water level. Since the piping system is open ended to the drywell atmosphere or torus, there is no potential for significant pressure transients due to gas accumulation. The pump discharge piping is, by design, voided. There have been no water hammer events during the plant operating history, which includes spurious system initiations and quarterly testing. The SDC system at OCNGS is designed to remove fission product decay heat during shutdown, and to provide a means of cooling the reactor pressure vessel to allow for refueling or maintenance following a period of operation. It is not required for mitigation of any event or accident evaluated in the UFSAR, and is not a safety related system. The SDC system is procedurally filled and vented prior to being put into service. The SDC system is only required to be free of gas accumulation prior to alignment. Therefore, the system is currently vented prior to use, and there are no CLB requirements for periodic venting of the system. AmerGen Energy Company, LLC's (AmorGen's) review concluded that no changes to the CLB for the SDC system are needed to address the potential for gas accumulation. AmerGen's review of the CLB for the CS, ICS, and Containment Spray systems identified no errors associated with implementation of existing licensing basis requirements and commitments. The CLB does not require periodic venting of the GL 2008-01 subject systems. Page 2 of 7 DESIGN EVALUATION Applicable Gas Volume Acceptance Criteria ATTACHMENT 7 Response for Oyster Creek Nuclear Generating Station AmerGen's evaluation concluded that clarifications or other changes to the TS and TS Bases might be warranted to enhance wording relative to gas accumulation issues for the GL 2008-01 subject systems. As a result, the following action is planned to ensure that the TS and TS Bases accurately reflect the technical considerations discussed in GL 2008-01. Potential TS improvements are being developed by the Technical Specifications Task Force (TSTF) with the goal of an NRC-approved TSTF Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. AmerGen is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. AmerGen will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF No other changes to OCNGS licensing basis documents were identified as a result of evaluations performed in response to GL 2008-01. The OCNGS design basis was reviewed with respect to gas accumulation in the CS, ICS, Containment Spray, and SDC systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included design basis documents, calculations, engineering evaluations, and vendor technical manuals. AmerGen's review of the design basis for these systems identified no deficiencies associated with implementation of existing design basis requirements. The systems are designed, tested, and operated in accordance with the TS and AmerGen's commitments to the applicable design criteria as described in the UFSAR. The design bases and operating procedures appropriately minimize and monitor for gas accumulation. Historically, station procedures associated with filling and venting the GL 2008-01 subject systems have not specified location-specific gas volume acceptance criteria. Rather, the procedures require vent valves to be opened, and a solid stream of water observed while venting. This practice ensures that the amount of air in systems is appropriately minimized to the extent practical, and ensures that systems are maintained condition of being sufficiently full following performance of vend such that the systems can perform their specified safety functions. Page 3 of 7 The impact of the voids on system operability is evaluated on a case-by-case basis, acceptable void volumes being determined as part of the evaluation. The evaluation process includes consideration of the impact that the void could have on pump operation, water hammer pressure transients, relief valve lifting, check valve closure, ATTACHMENT 7 Generic Letter 2008-01 Nine-Month Response for Oyster Creek Nuclear Generating Station I unbalanced loads, and accident and transient analyses. Industry guidance developed specifically in response to GL 2008-01 is also used. Chanctes Resulting from Desi No vulnerabilities were identified during the design basis document review. No changes to design basis documents were identified as being needed. and System Walkdowns Review Piping & instrumentation diagrams (PTCO) and isometric drawings were reviewed for the systems within the scope of GL 2008-01 to identify vents and high points. System high points include areas where gas can accumulate in the system, including isolated branch lines, valve bodies, heat exchangers, improperly sloped piping, or locations upstream of components in horizontal lines. As a result of the drawing reviews, AmerGen identified high points that may be susceptible to gas accumulation. These areas were further evaluated as discussed below. Using the results of the drawing review described above, AmerGen then performed detailed walkdowns of accessible system piping susceptible to gas accumulation. The walkdowns were performed to confirm pertinent design details (e.g., the location and orientation of system vents) and as-built configurations (e.g., pipe elevations and slope) to identify areas vulnerable to gas accumulation. Walkdowns of inaccessible piping sections will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for OCNGS. Results of the drawing reviews and system walkdowns were collectively evaluated to identify areas susceptible to gas accumulation that could potentially impact the systems' ability to perform their specified safety functions. These piping locations were further evaluated, and ultrasonic testing (UT) examinations were performed, where appropriate, to confirm whether voids were present. UT examinations were not performed on areas where an assessment concluded they were not necessary (e.g., a determination was made that voiding in the piping location would not impact the system's ability to perform its specified safety function, a determination was made that UT results from one train would be representative of results from a similar train). No new vent locations were deemed necessary to address vulnerabilities as a result of the evaluation of walkdown and UT examination results. AmerGen's review identified the need to implement the following corrective actions related to the design basis for the systems within the scope of GL 2008-01 for OCNGS. The schedule for completing the remaining corrective actions, and the basis for the scheduk;, ~re also provided below. 1 Walkdowns of inaccessible piping sections will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for OCNGS. The schedule for completing this action was discussed in AmerGen's three-month response to GL 2008-01 for OCNGS. Page 4 of 7 ATTACHMENT 7 Generic Letter 2008-01 Nine-Month Response for Oyster Creek Nuclear Genera verns venting of the SDC system fied that there are vents installed on the system that are not currently used frog activities. This procedure was revised to incorporate use of these g SDC system venting activities. Page 5 of 7 Procedure Reviews Associated With Fill and Vent Activities Station The process for filling and venting the GL 2008-01 subject systems is controlled through station procedures. The procedures have been used multiple times with acceptable results achieved during system restoration. The procedures are adequately segmented to permit appropriate flexibility in restoration of system piping segments based on the maintenance performed. These procedures, coupled with surveillance test procedures, provide the means to fill and vent the subject systems as well as purge air and other non-condensable gases from associated piping and components. Procedure OP-AA-108-106, "Equipment Return to Service," provides controls to assure the correct performance of activities related to the return to service of plant equipment. The guidance in the procedure is not system-specific
; rather, the procedure provides general requirements associated with returning plant equipment to service and clearance restoration. The procedure was revised as a result of the technical considerations identified in GL 2008-01 to require consideration of UT examinations to ensure proper fill and vent has been achieved. In addition, AmerGen plans to implement the following action to address enhancements to the procedures that govern fill and vent of the GL 2008-01 subject systems. AmerGen will revise procedures associated with fill and vent of the CS and Containment Spray systems to include requirements associated with the use of confirmatory UT examinations as part of system restoration activities as required. These changes are scheduled to be complete by October 24, 2008. This date ensures implementation prior to the start of the refueling outage and when the affected systems will be drained. The fill and vent procedures were evaluated to determine if the sequence of steps was effective and whether venting of instrument lines was included. AmerGen determined that the sequence of steps was effective; however, procedure revisions will be implemented to include requirements to verify affected instrument lines have been properly filled. AmerGen's review identified the need to implement the following corrective action related to the fill and vent procedures for the systems within the scope of GL 2008-01 for OCNGS. The schedule for completing this action, and the basis for the schedule, are also provided below. This action is necessary to address gaps that were identified to more accurately reflect the systems' susceptibility to adverse gas accumulation. AmerGen will revise procedures associated with fill and vent of the CS and Containment Spray systems to include requirements to verify affected instrument lines have been properly filled. These changes are scheduled to be complete by ATTACHMENT 7 Generic fetter 2008-01 Nine-Month Response for Oyster Creek Nuclear Generating Station October 24, 2008. This date ensures implementation prior to the start of the g outage and when the affected systems will be drained. Potential Gas Intrusion Mechanisms Examples of mechanisms that can result in unacceptable gas intrusion include: Poor refill and vent after draining, Steam intrusion, Gas coming out of solution over time, and Gas intrusion from an inter-connected system. In conjunction with the actions discussed within this attachment, AmerGen's review of system design and operating practices concluded that the systems are adequately monitored and tested for these potential gas intrusion mechanisms. This review included restoration procedures (i.e., system venting procedures), system design, interfaces with other systems, potential external sources of gas, and operating practices. Ongoing lndu stm Programs Ongoing industry programs are planned which may impact the conclusions reached during the design evaluation of OCNGS relative to gas accumulation, or may result in additional changes to the OCNGS design to provide additional margin. C. TESTING EVALUATION OCNGS test procedures were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. An industry-recommended template was followed to perform this review, and results have been documented. There are no periodic venting requirements for the ICS, Containment Spray, and SDC systems due to the design of the systems as discussed in the Licensing Basis Evaluation section above. Periodic venting of the CS system is currently performed on a weekly basis in accordance with station procedures. These procedures were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. These procedures do not specify gas volume acceptance criteria that must be met to satisfy the surveillance. Rather, the procedure requires vent valves to be opened, and a solid stream of water must be observed while venting. This is consistent with AmerGen's goal of returning systems to a condition of being sufficiently full following performance of venting surveillances, such that the systems can perform their specified safety functions. UT examinations are not currently performed during periodic system testing. However, since performance of UT examinations provide a consistent process to confirm the Page 6 of 7 ATTACHMENT 7 Generic Letter 2008-01 Nine-Month Response for Oyster Creek Nuclear Generating Station presence of voids, AmerGen plans to implement a graded approach for performing periodic UT examinations of susceptible piping locations. In summary, AmerGen's review of periodic testing activities identified the need to implement the following corrective action to address improvements to the procedures that govern periodic venting of the CS, Containment Spray, and SDC systems. AmerGen will revise the periodic venting procedure for the CS system to include enhanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points. These changes are scheduled to be complete by April 30, 2009. This schedule is reasonable based on the fact that the evaluations and UT examinations performed to date on the GL 2008-01 subject systems have not identified vulnerabilities that challenge the operability of these systems. CORRECTIVE ACTIONS EVALUATION AmerGen's Corrective Action Program is used to document gas intrusion/accumulation issues as potential nonconforming conditions. As pal of AmerGen's Corrective Action Program, Issue Reports related to plant equipment are evaluated for potential impact on operability and reportability. Therefore, AmerGen's review concluded that issues involving gas intrusion/accumulation are properly entered, prioritized, and evaluated under the Corrective Action Program, E. CONCLUSION Based upon the reviews and changes discussed above, AmerGen has concluded that the GL 2008-01 subject systems are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance.
ATTACHMENT 8 Generic Letter 2008-01 Nine-Month Response for Peach Bottom Atomic Power Station This attachment contains the Peach Bottom Atomic Power Station (PBAPS) nine-month response to Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008. The following information is provided in this response: (a) a description of the results of evaluations that were performed pursuant to the requested actions; (b) a description of the corrective actions determined necessary to assure compliance with the quality assurance criteria in Sections III, V, X1, XVI, and XVII of 10 CFR 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," and the licensing basis and operating license with respect to the subject systems; and (c) a statement regarding which corrective actions have been completed, the schedule for the corrective actions not yet complete, and the basis for that schedule. The following PBAPS systems were determined to be in the scope of GL 2008-01: " High Pressure Coolant Injection (HPCI), " Core Spray (CS), and " Residual Heat Removal (RHR) (i.e., Low Pressure Coolant Injection (LPCI), Containment Cooling, and Shutdown Cooling modes of RHR). There are related issues that the nuclear industry is currently considering with respect to the overall performance of these systems (i.e., Generic Safety Issue 193, "BWR ECCS Suction Concerns"). Consistent with discussions in SECY 2008-108, "Summary of Activities Related to Generic Issues Program," resolution of these related issues would be addressed independent of GL 200401 and will not be addressed herein. LICENSING BASIS EVALUATION The PBAPS current licensing basis (CLB) was reviewed with respect to gas accumulation in the HPCI, CS, and RHR systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included the Technical Specifications (TS), TS Bases, Updated Final Safety Analysis Report (UFSAR), Technical Requirements Manual (TRM) and TRM Bases, responses to NRC generic communications, regulatory commitments, and license conditions. Ion Generation Company, LLC's (EGC's) review of the CLB for the HPCI, CS and RHR systems identified no errors associated with implementation of existing licensing basis requirements and commitments. PBAPS TS require verification that Emergency Core Cooling System (ECCS) piping (i.e., HPCI, CS, and LPCI) is filled with water from the pump discharge valve to the injection valve every 31 days. The TS Bases state that maintaining the pump discharge lines of the HPCI system, CS system, and LPCI subsystems full of water ensures that the ECCS will perform properly, injecting its full capacity into the Reactor Coolant System upon demand. The 31 day frequency is based on the gradual nature of void buildup in the ECCS piping, the procedural controls Page 1 of 6 ATTACHMENT 8 Generic Letter 2008-01 Nine-Month Response for Peach Bottom Atomic Power Station ystem operation, and operating experience. The subject systems and their procedures are in compliance with the PBAPS CLB. B. DESIGN EVALUATION evaluation concluded that clarifications or other changes to the TS and TS Bases ht be warranted to enhance wording relative to gas accumulation issues for the GL 2008-01 subject systems. As a result, the following action is planned to ensure that the TS and TS Bases accurately reflect the technical considerations discussed in GL 2008-01. Potential TS improvements are being developed by the Technical Specifications Task Force (TSTF) with the goal of an NRC-approved TSTF Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. No other changes to PBAPS licensing basis documents were identified as a result of evaluations performed in response to GL 2008-01. The PBAPS design basis was reviewed with respect to gas accumulation in the HPCI, CS, and RHR systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included design basis documents, calculations, engineering evaluations, and vendor technical manuals. EGC's review of the design basis for these systems identified no deficiencies associated with implementation of existing design basis requirements. The systems are designed, tested, and operated in accordance with the TS and EGC's commitments to the applicable design criteria as described in the UFSAR. The design bases and operating procedures appropriately minimize and monitor for gas accumulation. Applicable Gas Volume Acceptance Criteria Historically, station procedures associated with filling and venting the GL 2008-01 subject systems have not specified location-specific gas volume acceptance criteria. I Rather, the p observed while ve appropriately minimize in a condition of being sufficiently full following performance of venting surveillances such that the systems can perform their specified safety functions. erred, and a solid stream of water is practice ensures that the amount of air in systems is to the extent practical, and ensures that systems are maintained The impact of the voids on system operability is evaluated on a case-by-case basis, with acceptable void volumes being determined as pal of the evaluation. The evaluation process includes consideration of the impact that the void could have on pump Page 2 of 6 ATTACHMENT 8 Generic Letter 2008-01 Nine-Month Response for Peach Bottom Atomic Power Station operation, water hammer pressure transients, relief valve lifting, check valve closure, potential unbalanced loads, and accident and transient analyses. Industry guidance developed specifically in response to GL 2008-01 is also used. Chancres Resulting
_from Design _Basis Review No vulnerabilities were identified during the design basis document review. No changes to design basis documents were identified as being needed. Drawing Reviews and System Walkdowns
_ _ Piping & instrumentation diagrams (P&IDs) and isometric drawings were reviewed for the systems within the scope of GIL 2008-01 to identify vents and high points. System high points include areas where gas can accumulate in the system, including isolated branch lines, valve bodies, heat exchangers, improperly sloped piping, or locations upstream of components in horizontal lines. As a result of the drawing reviews, EGC identified high points that may be susceptible to gas accumulation. These areas were further evaluated as discussed below. Using the results of the drawing review described above, EGC then performed detailed walkdowns of accessible system piping susceptible to gas accumulation on both PBAPS units. The walkdowns were performed to confirm pertinent design details (e.g., the location and orientation of system vents) and as-built configurations (e.g., pipe elevations and slope) to identify areas vulnerable to gas accumulation. Detailed walkdowns of inaccessible piping sections will be completed during the next scheduled refueling outage for each PBAPS unit, as discussed in the three-month response to GL 2008-01 for PBAPS. Results of the drawing reviews and system walkdowns were collectively evaluated to identify areas susceptible to gas accumulation that could potentially impact the systems' ability to perform their specified safety functions. These piping locations were further evaluated, and ultrasonic testing (UT) examinations were performed, where appropriate, to confirm whether voids were present. UT examinations were not performed on areas where an assessment concluded they were not necessary (e.g., a determination was made that voiding in the piping location would not impact the system's ability to perform its specified safety function, a determination was made that system flow rates during periodic testing would be adequate to remove voids). No new vent locations were deemed necessary to address vulnerabilities as a result of the evaluation of walkdown and UT examination results. EGC's review identified the need to implement the following corrective action related to the design basis for t systems within the scope of GL 2008-01 for PBAPS. The schedule for completing this action was discussed in EGC's three-month response to GL 2008-01 for PBAPS. Page 3 of 6 Detailed walkdowns of inaccessible piping sections will be completed during the next scheduled refueling outage for each PBAPS unit, as discussed in the three-month response to GL 2008-01 for PBAPS.
ATTACHMENT 8 Generic Letter 2008-01 Nine-Month Response for Peach Bottom Atomic Power Station Procedure The process for filling and venting the GL 2008-01 subject systems is controlled through station procedures. The procedures have been used multiple times with acceptable results achieved during system restoration. The procedures are adequately segmented to permit appropriate flexibility in restoration of system piping segments based on the rformed. These procedures, coupled with surveillance test procedures, to fill and vent the subject systems as well as purge air and other gases from associated piping and components. sociated With Fill and Vent Activities Procedure OP-AA-108-106, "Equipment Return to Service," provides controls to assure the correct performance of activities related to the return to service of plant equipment. The guidance in the procedure is not system-specific
; rather, the procedure provides general requirements associated with returning plant equipment to service and clearance restoration. The procedure was revised as a result of the technical considerations identified in GL 2008-01 to require consideration of LIT examinations to ensure proper fill and vent has been achieved. In addition, EGC plans to implement the following action to address enhancements to the procedures that govern fill and vent of the GL 2008-01 subject systems. EGC will revise procedures associated with fill and vent of the GL 2008-01 subject systems to include additional requirements associated with the use of confirmatory UT examinations as part of system restoration activities as required. These changes are scheduled to be complete by February 27, 2009. This date is reasonable because PBAPS Unit 2 is currently in a refueling outage, and EGC has implemented administrative controls, via manual activities in work orders, to perform confirmatory UT examination as part of system restoration activities. In addition, a review of online maintenance activities has been performed, and use of these procedures is not currently planned prior to the scheduled date for revision. The fill and vent procedures were evaluated to determine if the sequence of steps was effective and whether venting of instrument lines was included. EGC determined that the sequence of steps was effective; however, procedure revisions will be implemented to include requirements to verify affected instrument lines have been properly filled. EGC's review identified the need to implement the following corrective action related to the fill and vent procedures for the systems within the scope of GL 2008-01 for PBAPS. The schedule for completing this action, and the basis for the schedule, are also provided below. This action is necessary to address gaps that were identified to more accurate" reflect the systems" susceptibility to adverse gas accumulation. EGC will revise procedures associated with fill and vent of the GL 2008-01 subject systems to include requirements to verify affected instrument lines have been properly filled. These changes are scheduled to be complete by February 27, 2009. This date is reasonable because PBAPS Unit 2 is currently in a refueling outage, and EGC has implemented administrative controls, via manual activities in work orders, to perform confirmatory UT examination as part of system restoration activities. In Page 4 of 6 Generic ATTACHMENT 8 2008-01 Nine-Month Response for Peach Bottom Atomic Power Station addition, a review of online maintenance activities has been performed, and use of these procedures is not currently planned prior to the scheduled date for revision. Potential Gas Intrusion Mec Examples of mechanisms that can result in unacceptable gas intrusion include: Poor refill and vent after a return-to-se Steam intrusion, Gas coming out of solution over time, and Gas intrusion from an inter-connected system. In conjunction with the actions discussed within this attachment, EGC's review of system design and operating practices concluded that the systems are adequately monitored and tested for these potential gas intrusion mechanisms. This review included restoration procedures (i.e., system venting procedures), system design, interfaces with other systems, potential external sources of gas, and operating practices. Onc Loing Industry Programs C. TESTING EVALUATION Ongoing industry programs are planned which may impact the conclusions reached during the design evaluation of PBAPS relative to gas accumulation, or may result in additional changes to the PBAPS design to provide additional margin. PBAPS test procedures were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. An industry-recommended template was followed to perform this review, and results have been documented. Periodic venting of the HPCI, CS, and RHR systems is currently performed in accordance with TS Surveillance Requirement (SR) 3.5.1.1. PBAPS test procedures that govern the performance of SR 3.5.1.1 were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. These procedures do not specify gas volume acceptance criteria that must be met to satisfy the surveillance. Rather, the procedures require vent valves to be opened, and a solid stream of water must be observed while venting. This is consistent with EGC's goal of returning systems to a condition of being sufficiently full following performance of venting surveillances, such that the systems can perform their specified safety functions. UT examinations are not currently performed during periodic system testing. However, since performance of LIT examinations provide a consistent process to confirm the presence of voids, EGC plans to implement a graded approach for performing periodic LIT examinations of susceptible piping locations. Page 5 of 6 ATTACHMENT 8 Generic Letter 2008-01 Nine-Month Response for Peach Bottom Atomi In summary, EGC's review of periodic testing activities identified the need to implement the following corrective action to address improvements to the procedures that govern venting of the HPCI, CS, and RH a EGC will revise periodic venting procedures for the GL 2008-01 subject systems to acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points. These changes are scheduled to be complete by April 30, 2009. This schedule is reasonable based on the fact that the evaluations and UT examinations performed to date on the GL 2008-01 subject systems have not identified vulnerabilities that challenge the operability of these systems. CORRECTIVE ACTIONS EVALUATION EGC's Corrective Action Program is used to document gas intrusion/accumulation issues as potential nonconforming conditions. As part of EGC's Corrective Action Program, Issue Reports related to plant equipment are evaluated for potential impact on operability and reportability. Therefore, EGC's review concluded that issues involving gas intrusion/accumulation are properly entered, prioritized, and evaluated under the Corrective Action Program. CONCLUSION Based upon the reviews and changes discussed above, EGC has concluded that the GL 2008-01 subject systems are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance. er Station ATTACHMENT 9 Generic Letter 2008-01 Nine-Month Response for Quad Cities Nuclear Power Station This attachment contains the Quad Cities Nuclear Power Station (QCNPS response to Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008. The following information is provided in this response: (a) a description of the results of evaluations that were performed pursuant to the requested ns; (b) a description of the corrective actions determined necessary to assure compliance with the quality assurance criteria in Sections 111, V, X1, XVI, and XVII of 10 CFR 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," and the licensing basis and operating license with respect to the subject systems; and (c) a statement regarding which corrective actions have been completed, the schedule for the corrective actions not yet complete, and the basis for that schedule. The following QCNPS systems were determined to be in the scope of GL 2008-01: " High Pressure Coolant Injection (HPCI), " Core Spray (CS), " Residual Heat Removal (RHR) (i.e., Low Pressure Coolant Injection (LPCI), Shutdown Cooling, and Containment Cooling modes of RHR). There are related issues that the nuclear industry is currently considering with respect to the overall performance of these systems (i.e., Generic Safety Issue 193, "BWR ECCS Suction Concerns"). Consistent with discussions in SECY 2008-108, "Summary of Activities Related to Generic Issues Program," resolution of these related issues would be addressed independent of GL 2008-01 and will not be addressed herein. A. LICENSING BASIS EVALUATION The QCNPS current licensing basis (CLB) was reviewed with respect to gas accumulation in the HPCI, CS, and RHR systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included the Technical Specifications (TS), TS Bases, Updated Final Safety Analysis Report (UFSAR), Technical Requirements Manual (TRM) and TRM Bases, responses to NRC generic communications, regulatory commitments, and license conditions. Exelon Generation Company, LLC's (EGC's) review of the CLB for the HPCI, CS, and RHR systems identified no errors associated with implementation of existing liven basis requirements and commitments. QCNPS TS require verification that Emergency Core Cooling System (ECCS) piping (i.e., HPCI, CS, and LPCI) is full of water from the pump discharge valve to the injection valve every 31 days. The TS Bases state that maintaining the pump discharge lines of the HPCI system, CS system, and LPCI subsystems full of water ensures that the ECCS will perform properly, injecting its full capacity into the Reactor Coolant System upon demand. The 31 day frequency is based on operating experience, on the procedural controls governing system operation, and on Page 1 of 6 ATTACHMENT 9 Generic Letter 2008-01 Nine-Month Response for Quad Cities Nuclear Power Station the gradual nature of void buildup in the ECCS p procedures are in compliance with the QCNPS CLB. EGC's evaluation concluded that clarifications or other changes to the TS and TS Bases might be warranted to enhance wording relative to gas accumulation issues for the GL 2008-01 subject systems. As a result, the following action is planned to ensure that the TS and TS Bases accurately reflect the technical considerations discussed in GL 2008-01. Potential TS improvements are being developed by the Technical Specifications Task Force (TSTF) with the goal of an NRC-approved TSTF Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. No other changes to QCNPS licensing basis documents were identified as a result of evaluations performed in response to GL 2008-01. B. DESIGN EVALUATION The QCNPS design basis was reviewed with respect to gas accumulation in the HPCI, CS, and RHR systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included design basis documents, calculations, engineering evaluations, and vendor technical manuals. EGC's review of the design basis for these systems identified no deficiencies associated with implementation of existing design basis requirements. The systems are designed, tested, and operated in accordance with the TS and EGC's commitments to the applicable design criteria as described in the UFSAR. The design bases and operating procedures appropriately minimize and monitor for gas accumulation. Applicable Gas Volume Acceptance Criteria QCNPS venting procedures require a solid stream of water be observed for a specified duration as a requirement for considering the system full. The monthly vent verifications ded acceptance criteria for the amount of air that is measured in the system. These criteria are used to determine the impact on system operability when venting activities identify a system is not completely full. Station procedures require an Issue Report to be initiated if the acceptance criteria are exceeded. The subject systems and their No additional vent verification testing corrective actions were identified to ensure that gas accumulation is maintained less than the amount that challenges operability.
ATTACHMENT 9 Generic Letter 2008-01 Nine-Month Response for Quad Cities Nuclear Power Station Changes ResultinQ from Design Basis Review No vulnerabilities were identified during the design basis document review. No changes to design basis documents were identified as being needed. Reviews and System Walkdow- Piping & instrumentation diagrams (P&IDs) and isometric drawings were reviewed for the systems within the scope of GL 2008-01 to identify vents and high points. System high points include areas where gas can accumulate in the system, including isolated branch lines, valve bodies, heat exchangers, improperly sloped piping, or locations upstream of components in horizontal lines. As a result of the drawing reviews, EGC identified high points that may be susceptible to gas accumulation. These areas were further evaluated as discussed below. Using the results of the drawing review described above, EGC then performed detailed walkdowns of system piping susceptible to gas accumulation on Unit 2, as well as accessible piping sections susceptible to gas accumulation on Unit 1. The walkdowns were performed to confirm pertinent design details (e.g., the location and orientation of system vents) and as-built configurations (e.g., pipe elevations and slope) to identify areas vulnerable to gas accumulation. Detailed walkdowns of inaccessible piping sections on Unit 1 will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for QCNPS. Results of the drawing reviews and system walkdowns were collectively evaluated to identify areas susceptible to gas accumulation that could potentially impact the systems' ability to perform their specified safety functions. These piping locations were further evaluated, and ultrasonic testing (UT) examinations were performed, where appropriate, to confirm whether voids were present. UT examinations were not performed on areas where an assessment concluded they were not necessary (e.g., a determination was made that voiding in the piping location would not impact the system's ability to perform its specified safety function, a determination was made that UT results from one train would be representative of results from a similar train, a determination was made that system flow rates during periodic testing would be adequate to remove voids). No new vent locations were deemed necessary to address vulnerabilities as a result of the evaluation of walkdown and UT examination results. EGC's review identified the need to implement the following corrective action related to the design basis for the ms within the scope of GL 2008-01 for QCNPS. The schedule for completing this iscussed in EGC's three-month response to GL 2008-01 for QCNPS. Detailed walkdowns of inaccessible piping sections on Unit 1 will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for QCNPS.
ATTACHMENT 9 Generic Letter 2008-01 Nine-Month Response for Quad Cities Nuclear Power Station ssociated With Fill and Vent Activi process for filling and venting the GL 2008-01 subject systems is controlled through educes. The procedures have been used multiple times with acceptable ieved during system restoration. The procedures are adequately segmented appropriate flexibility in restoration of system piping segments based on the ante performed. These procedures, coupled with surveillance test procedures, provide the means to fill and vent the subject systems as well as purge K and other non-condensable gases from associated piping and components. Procedure OP-AA-108-106, "Equipment Return to Service," provides controls to assure the correct performance of activities related to the return to service of plant equipment. The guidance in the procedure is not system-specific
; rather, the procedure provides general requirements associated with returning plant equipment to service and clearance restoration. The procedure was revised as a result of the technical considerations identified in GL 2008-01 to require consideration of UT examinations to ensure proper fill and vent has been achieved. In addition, EGC plans to implement the following action to-address-enhancements to the procedures that govern fill and vent of the GL 2008-01 subject systems. EGC will revise procedures associated with fill and vent of the GL 2008-01 subject systems to include additional requirements associated with the use of confirmatory UT examinations as part of system restoration activities as required. These changes are scheduled to be complete by March 31, 2009. This schedule is acceptable because there are no planned refueling outages in this timeframe. Furthermore, periodic venting procedures ensure systems are sufficiently full and include acceptance criteria for identifying unacceptable void conditions. The fill and vent procedures were evaluated to determine if the sequence of steps was effective and whether venting of instrument lines was included. EGC determined that the sequence of steps was effective; however, procedure revisions will be implemented as necessary to include requirements to verify affected instrument lines have been properly filled. EGC's review identified the need to implement the following corrective action related to the fill and vent procedures for the systems within the scope of GL 200401 for QCNPS. This action is necessary to address gaps that were identified to more accurately reflect the systems' susceptibility to adverse gas accumulation. EGC will revise fill and vent procedures to include requirements to verify as necessary affected instrument lines have been properly filled. These changes a scheduled to be complete by March 31, 2009, This schedule is acceptable because there are no planned refueling outages in this timeframe. Furthermore, general work practices ensure sensing lines are filled and vented following instrument maintenance that could potentially drain these lines.
ATTACHMENT 9 Generic Letter 2008-01 Nine-Month Response for Quad Cities Nuclear Power Station Potential Gas Intrusion Mechanisms Examples of mechanisms that can result in unacceptable gas intrusion include: Poor refill and vent after a return-to-service, Steam intrusion, Gas coming out of solution over time, and Gas intrusion from an inter-connected system. In conjunction with the actions discussed within this attachment, EGC's review of system design and operating practices concluded that the systems are adequately monitored and tested for these potential gas intrusion mechanisms. This review included restoration procedures (i.e., system venting procedures), system design, interfaces with other systems, potential external sources of gas, and operating practices. No corrective actions were identified to ensure that gas accumulation is maintained less than the amount that challenges operability. Ongoing Industry Programs Ongoing industry programs are planned which may impact the conclusions reached during the design evaluation of QCNPS relative to gas accumulation, or may result in additional changes to the QCNPS design to provide additional margin. C. TESTING EVALUATION QCNPS test procedures were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. An industry-recommended template was followed to perform this review, and results have been documented. Periodic venting of the HPCI, CS, and RHR systems is currently performed in accordance with TS Surveillance Requirement (SR) 3.5.1.1. QCNPS test procedures that govern the performance of SR 3.5.1.1 were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. Page 5 of 6 There were no vulnerabilities identified during the system testing reviews. The procedures require vent valves to be opened, and a solid stream of water must be observed while venting. This is consistent with EGC's goal of returni condition of being sufficiently full following performance of venting surveillances, such that the systems can perform their specified safety functions. If the system piping is found not full, the monthly vent verification procedures already included acceptance is for the amount of air that is measured in the system. UT examinations are not currently performed during periodic system testing. However, ce performance of UT examinations provide a consistent process to confirm the e of voids, EGC plans to implement a graded approach for performing periodic of susceptible piping locations. In summary, EGC the following correct periodic venting of the CONCLUSION ATTACHMENT 9 008-01 Nine-Month Response for Quad Cities Nuclear Power Station of periodic testing activities identified the need to implement coon to address improvements to the procedures that govern CS, and RHR systems. e periodic venting procedures for the GL 2008-01 subject systems to enhanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points. These changes are scheduled to be complete by April 30, 2009. This schedule is acceptable because periodic venting procedures require a solid stream of water be observed for a specified duration as a requirement for considering the system full. Acceptance criteria are provided for identifying unacceptable void conditions. CORRECTIVE ACTIONS EVALUATION EGC's Corrective Action Program is used to document gas intrusion/accumulation issues as potential nonconforming conditions. As part of EGC's Corrective Action Program, Issue Reports related to plant equipment are evaluated for potential impact on operability and reportability. Therefore, EGC's review concluded that issues involving gas intrusion/accumulation are properly entered, prioritized, and evaluated under the Corrective Action Program. Based upon the reviews and changes discussed above, EGC has concluded that the GL 2008-01 subject systems are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance.
ATTACHMENT 1 0 Letter 2008-01 Nine-Month Response for Three Mile Island Nuclear Station This attachment contains the Three Mile Island Nuclear Station (TMI) Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Heat Removal, and Containment Spray Systems," dated January 11, 2008. The following information is provided in this response: (a) a description of the results of evaluations that were performed pursuant to the requested actions; (b) a description of the corrective actions determined necessary to assure compliance with the quality assurance criteria in Sections 111, V, X1, XVI, and XVII of 10 CFR 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," and the licensing basis and operating license with respect to the subject systems; and LICENSING BASIS EVALUATION (c) a statement regarding which corrective actions have been completed, the schedule for the corrective actions not yet complete, and the basis for that schedule. The following TMI systems were determined to be in the scope of GL 2008-01: " Makeup and Purification (MU) - portion that performs or affects High Pressure Injection (HPI) function, " Decay Heat Removal (DH) - including Low Pressure Injection (LPI) function, " Core Flooding (CF), and " Building Spray (BS). The TMI current licensing basis (CLB) was reviewed with respect to gas accumulation in the HPI, DH, CF, and BS systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included the Technical Specifications (TS), TS Bases, Updated Final Safety Analysis Report (UFSAR), responses to NRC generic communications, regulatory commitments, and license conditions. AmerGen Energy Company, LLC's (AmerGen's) review of the CLB for the HPI, DH, CF, and BS systems identified no errors; associated with implementation of existing licensing basis requirements and commitments. TMI TS for the HPI and DH systems require venting during each refueling interval and following maintenance or modification that affects system flow characteristics. There are no periodic venting or void verifica check requirements in the CLB for the HPI, DH, and BS. Although not required by 1 TMI is currently performing initial fill ultrasonic testing (UT) checks, post-maintenance fill LIT checks, and periodic UT checks for the HPI, DH, and BS systems. The CF system is a self-contained, self-actuating passive system. Two tanks are two-thirds full of borated water, with the upper one-third filled with nitrogen. When Reactor Coolant System pressure drops to 600 prig, two in-series check valves open from each tank to allow water to directly flow to the reactor vessel. There are no pumps in the system, and the pipes slope upwards to the tanks to ensure no void formation. Since Page 1 of 6 ATTACHMENT 10 Generic Letter 2008-01 Nine-Month Response for Three Mile Island Nuclear Station the CF system is not susceptible to gas accumu for venting any portion of the system. o CLB requirements AmerGen's evaluation concluded that clarifications or other changes to the TS and TS Bases might be warranted to enhance wording relative to gas accumulation issues for the GL 2008-01 subject systems. As a result, the following action is planned to ensure that the TS and TS Bases accurately reflect the technical considerations discussed in GL 2008-01. Potential TS improvements are being developed by the Technical Specifications Task Force (TSTF) with the goal of an NRC-approved TSTF Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. AmerGen is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. AmerGen will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. No other changes to TMI licensing basis documents were identified as a result of evaluations performed in response to GL 2008-01. B. DESIGN EVALUATION The TMI design basis was reviewed with respect to gas accumulation in the HPI, DH, CF, and BS systems. An industry-recommended template was followed to perform this review, and results have been documented. This review included design basis documents, calculations, engineering evaluations, and vendor technical manuals. AmerGen's review of the design basis for these systems identified no deficiencies associated with implementation of existing design basis requirements. The systems are designed, tested, and operated in accordance with the TS and AmerGen's commitments to the applicable design criteria as described in the UFSAR. The design bases and operating procedures appropriately minimize and monitor for gas accumulation. As a result of issues with gas accumulation prior to the issuance of GL 2008-01, extensive evaluations were performed in the 2006-2007 timeframe. These evaluations included detailed walkdowns of systems and UT examinations of piping sections susceptible to gas accumulation. In addition, 16 new vent locations were installed on the BS, DH, and HPI systems. These modifications are complete. Gas Volume Acceptance Criteria Void volume acceptance criteria have been established at TMI. The acceptance criteria are used for periodic UT checks as well as post-maintenance fill and vent UT checks. The criteria allow less than five percent voids in discrete high point locations on the suction side of the LPI pumps and two percent voids in discrete high point locations on the suction and discharge side of the HPI pumps. The acceptance criteria are supported Page 2 of 6 Gener ATTACHMENT 10 Letter 2008-01 Nine-Month Response for Three Mile Island Nuclear Station by technical evaluation and GOTHIC computer modeling that ensures proper pump Previous venting methods swept system voids from the piping during ull flow or quarterly inservice testing, and no water hammer events occurred. rational experience and engineering judgment is used to support the current acceptance criteria. Small ribbons of air at discrete locations are considered inconsequential. No ribbons or voids have been found after two years of periodic UT examinations. Identified voids are documented in the Corrective Action Program by initiating an Issue Report. Detailed evaluation for the particular void size and location would follow. Changes Resulting from Design Basis Rev .q Reviews and System Walkdowns a - No vulnerabilities were identified during the design basis document review. No changes to design basis documents were identified as being needed. Piping & instrumentation diagrams (P&IDs) and isometric drawings were reviewed for the systems within the scope of GL 2008-01 to identify vents and high points. System high points include areas where gas can accumulate in the system, including isolated branch lines, valve bodies, heat exchangers, improperly sloped piping, or locations upstream of components in horizontal lines. Walkdowns were also performed to confirm pertinent design details (e.g., the location and orientation of system vents) and as-built configurations (e.g., pipe elevations and slope) to identify areas vulnerable to gas accumulation. In 2006 and 2007, HPI, DH, and BS system piping outside the Reactor Building was walked down. For the DH system, multiple locations were identified with high points that were not vented, and 12 new vent locations were installed. Three new vent locations were also installed on the BS system in 2006 and 2007 as a result of the drawing reviews and system walkdowns. In addition, one new vent location was installed on the HPI system. HPI, DH, and BS DH system piping inside the Reactor Building was not walked down in 2006 and 2007; however, system drawings, photos, and system knowledge was used to evaluate the potential for voids in the system. The BS system piping inside the Reactor Building was not measured, since the piping is drained per design until initiation. The CF system is not susceptible to gas accumulation
; therefore, no system walkdowns are required for the CF system. Confirmatory detailed walkdowns of inaccessible piping sections on the HPI and DH systems will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for Tt In 2006 and 2007, results of the drawing reviews and system walkdowns were collectively evaluated to identify areas susceptible to gas accumulation that could potentially impact the systems' ability to perform their specified safety functions. These piping locations were further evaluated, and UT examinations were performed, where appropriate, to confirm whether voids were present. UT examinations were not performed on areas where an assessment concluded they were not necessary (e.g., a Page 3 of 6 Gener ATTACHMENT 10 Letter 2008-01 Nine-Month Response for Three Mile Island Nuclear Station motion was made that voiding in the piping location would not impact the system's ability to perform its specified safety function). AmerGen's review identified the need to implement the following corrective action related to the design basis for the systems within the scope of GL 2008-01 for TMI. The schedule for completing this action was discussed in AmerGen's three-month response to GL 2008-01 for TMI. Detailed walkdowns of inaccessible piping sections will be completed during the next scheduled refueling outage, as discussed in the three-month response to GL 2008-01 for TMI. Procedure Reviews Associated With Fill and Vent Activities The process for filling and venting the GL 2008-01 subject systems is controlled through station procedures. The procedures have been used multiple times with acceptable results achieved during system restoration. The procedures are adequately segmented to permit appropriate flexibility in restoration of system piping segments based on the maintenance performed. These procedures, coupled with surveillance test procedures, provide the means to fill and vent the subject systems as well as purge air and other non-condensable gases from associated piping and components. Procedure OP-AA-108-106, "Equipment Return to Service," provides controls to assure the correct performance of activities related to the return to service of plant equipment. The guidance in the procedure is not system-specific
; rather, the procedure provides general requirements associated with returning plant equipment to service and clearance restoration. The procedure was revised as a result of the technical considerations identified in GL 2008-01 to require consideration of UT examinations to ensure proper fill and vent has been achieved. In addition, TMI procedures for the GL 2008-01 subject systems also include steps associated with the use of UT examinations during system restoration activities as required. The fill and vent procedures were evaluated to determine if the sequence of steps was effective and whether venting of instrument lines was included. AmerGen determined that the sequence of steps was effective, and appropriately include considerations for instrument lines. In summary, no corrective actions related to fill and vent procedures were identified as being necessary to address gas accumulation issues. Potential Gas Intrusion Mechanisms Examples of mechanisms that can result 0 0 Poor refill and vent after a return-to-service, Gas coming out of solution over time, and Gas intrusion from an inter-connected system. Page 4 of 6 eptable gas intrusion include:
ATTACHMENT 10 Generic Letter 2008-01 Nine-Month Response for Three Mile Island Nuclear Station In conjunction with the actions discussed within this attachment, AmerGen's review of system design and operating practices concluded that the systems are adequately monitored and tested for these potential gas intrusion mechanisms. This review restoration procedures (i.e., system venting procedures), system design, ith other systems, potential external sources of gas, and operating practices. Onqoinq IndustN Programs Ongoing industry programs are planned in the following areas which may impact the conclusions reached during the design evaluation of TMI relative to gas accumulation, or may result in additional changes to the TMI design to provide additional margin. 0 Gas Transport in Pump Suction Piping The Pressurized Water Reactor Owners' Group has initiated testing to provide additional knowledge relative to gas transport in large diameter piping. One program performed testing of gas transport in 6-inch and 8-inch piping. Another program will perform additional testing of gas transport in 4-inch and 12-inch low temperature systems and 4-inch high temperature systems. This program will also integrate the results of the 4-inch, 6-inch, 8-inch, and 12-inch testing. 0 Pump Acceptance Criteria C. TESTING EVALUATION Long-term industry tasks were identified that will provide additional tools to address GL 2008-01 with respect to pump gas void ingestion tolerance limits. TMI test procedures were reviewed to determine whether the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, and whether the procedures require documentation of appropriate records. An industry-recommended template was followed to perform this review, and results have been documented. There are no CLB requirements to periodically vent the GL 2008-01 subject systems. However, periodic monitoring of the HPI, DH, and BS systems is currently being performed in accordance with station procedures. AmerGen's review of the TMI test procedures concluded the procedures incorporate the requirements and acceptance limits contained in applicable design and licensing documents, the procedures require documentation of appropriate records, the procedures require identified gas voids to be entered into the Corrective Action Program for evaluation and disposition, and the procedures require periodic UT verifications. No corrective actions related to the TMI test procedures are required 5) address the potential for gas accumulation. D. CORRECTIVE ACTIONS EVALUATION AmerGen's Corrective Action Program is used to document gas intrusion/accumulation issues as potential nonconforming conditions. As part of AmerGen's Corrective Action Page 5 of 6 ATTACHMENT 10 Generic Letter 2008-01 Nine-Month Response for Three Mile Island Nuclear Station Program, Issue Reports related to plant equipment are evaluated for potential impact on operability and reportability. Therefore, AmerGen's review concluded that issues involving gas intrusion/accumulation are properly entered, prioritized, and evaluated under the Corrective Action Program. CONCLUSION Based upon the reviews and changes discussed above, AmerGen has concluded that the GL 2008-01 subject systems are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance.
The following list identifies those actions committed to by Exelon Generation Company, LLC, (EGC) for Braidwood Station in this submittal. Any other actions discussed in the submittal represent intended or planned actions by EGC, are described only for information, and are not regulatory commitments. Station COMMITMENT TYPE ONE-TIME PROGRAM- ACTION MATI COMMITTED DATE COMMITMENT OR "OUTAGE" (YESINO) (YES/NO) Potential TS improvements are 180 days after NRC Yes No being developed by the TSTF with approval of the TSTF the goal of an NRC-approved TSTF Traveler Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF EGG will revise procedures December 31, 2008 No Yes associated with fill and vent of the GL 2008-01 subject systems to include requirements to verify affected instrument lines have been properly Bed. I COMMITMENT EGC will revise periodic venting procedures for the GIL 2008-01 subject systems to include hanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting rifications of accessible high points. ATTACHMENT 11 Regulatory Commitments for Braidwood Station ONE-TIME PROGRA ACTION MATIC COMMITTED DATE , OR "OUTAGE" 1 (YES/NO) April 30,2009 COMMITMENT TYPE No (YES/NO) Yes ATTACHMENT 12 Regulatory Commitments for Byron Station g list identifies those actions committed to by Exelon Generation Company, LLC, Byron Station in this submittal. Any other actions discussed in the submittal represent or planned actions by EGC, are described only for information, and are not regulatory COMMITMENT TYPE ONE-TIME PROGRAM- ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YES/NO) ~ (YES/NO) 1 1 Potential TS improvements are 180 days after NRC ~ Yes No being developed by the TSTF with ~ approval of the TSTF the goal of an NRC-approved TSTF Traveler Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. EGC will revise procedures December 31, 2008 No Yes associated with fill and vent of the ~ GL 2008-01 subject systems to include requirements to verify affected instrument lines have been properly filled.
ATTACHMENT 12 Regulatory Commitments for Byron Sta COMMITMENT will revise periodic venting cedures for the GL 2008-01 subject systems to include ced acceptance criteria and ements to perform UTs on a graded approach as part of venting rifications of accessible high points. ONE-TIME PROGRAM-MATIC ACTION O) 1 (YES/NO) Yes COMMITTED DATE 1 OR "OUTAGE" {YES/ April 010, 2009 i I I I I No ATTACHMENT 13 Regulatory Commitments for Clinton Power Station list identifies those actions committed to by AmerGen Energy Company, LLC (AmerGen) for Clinton Power Station in this submittal. Any other actions discussed in the submittal represent intended or planned actions by AmerGen, are described only for information, and are not regulatory commitments. COMMITMENT TYPE ONE-TIME PROGRAM- ACTION MATIc COMMITTED DATE COMMITMENT
~ OR "OUTAGE" (YESINO) (YES/NO) Potential TS improvements are 180 days after NRC Yes No being developed by the TSTF with approval of the TSTF the goal of an NRC-approved TSTF Traveler Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. AmerGen is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. AmerGen will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. For the HPCS system, one new vent Prior to startup from the i Yes No I will be installed prior to startup from ~ next refueling outage I the next refueling outage. For the RHR system, a modification I Prior to startup from the Yes No will be installed to add vent and next refueling outage drain holes to an orifice.
ATTACHMENT 13 Regulatory Commitments for Clinton Power Station COMMITMENT TYPE ONE-TIME PROGRAM- ACTION MATI COMMITTED DATE COMMITMENT OR "OUTAGE" YES/NO) (YES/NC) AmerGen will vrevise roc procedures
~ January 9, 2009 No Yes CPS CPS 330 09.01, CPS 3333122.01, and CPS S 1331301.011 t to o l include u e requirements to t" verify rif~/ affected affected instrument lines have been properly filled as part of system restoration activities. AmerGen will revise periodic venting April 30, 2009 No Yes procedures for the GL 2008-01 subject systems to include enhanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points.
ATTACHMENT 14 Regulatory Commitments for Dresden Nuclear Power Station coons committed to by Exelon Generation Company, LLC, r Power Station in this submittal. Any other actions discussed in the ittal represent intended or planned actions by EGC, are described only for information, and are not regulatory commitments. COMMITMENT TYPE ONE-TIME 1 PROGRAM- ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YESINO) {YES/NO) Potential TS improvements are 180 days after NRC Yes No being developed by the TSTF with approval of the TSTF j the goal of an NRC-approved TSTF Traveler Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF EGC's review of procedures that October 31, 2008 No Yes govern venting of the SDC system ~ identified there are several vents installed on the system that are not currently used during venting activities. These procedures will be revised to incorporate use of additional vents to enhance venting practices.
ATTACHMENT 14 Regulatory Commitments for Dresden Nuclear Power Station COMMITMENT COMMITMENT TYPE ONE-TIME 'PROGRAM-ACTION MATIC 's COMMITTED DATE j OR "OUTAGE" j (YES/NO) (YES/NO) EGC will revise the procedure October 31, 2008 No Yes associated with fill and vent of the j LPCI system to include E requirements to verify affected I instrument lines have been properly filled. EGC will revise periodic venting April 30, 2009 No Yes surveillances for the HPCI, LPCI, and CS systems to include enhanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points.
ATTACHMENT 15 Regulatory Commitments for LaSalle County Station The following list identifies those actions committed to by Exelon Generation Company, LLC, (EGC) An LaSalle County Station in this submittal. Any other actions discussed in the submittal represent intended or planned actions by EGC, are described only for information, and are not regulatory commitments. COMMITMENT TYPE ONE-TIME 'PROGRAM-ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YES/NO} (YES/NO) Potential TS improvements are 180 days after NRC Yes No being developed by the TSTF with approval of the TSTF the goal of an NRC-approved TSTF Traveler Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF ATTACHMENT 15 Regulatory Commitments for LaSalle County Station COMMITMENT TYPE ONE-TIME 1 PROGRAM- ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YES/NO) (YES/NO) The HPCS system is connected to Complete No Yes the Reactor Coolant System (RCS) through the injection line, which includes a normally closed injection valve and injection check valve. RCS leakage past both these valves would result in actuation of a pressure switch, actuation of a control room annunciator, and entry into the associated alarm response procedure. This procedure was revised to provide direction for identifying a temperature increase that could lead to saturated conditions within the piping, which could result in void formation, The LPCS system is connected to Complete No Yes the RCS through the injection line, which includes a normally closed injection valve and injection check valve. RCS leakage past both these valves would result in actuation of a pressure switch, actuation of a control room annunciator, and entry into the associated alarm response procedure. This procedure was revised to provide direction for identifying a temperature increase that could lead to saturated conditions within the piping, which could result in void formation.
Regulatory Commitments for LaSalle County Station COMMITMENT TYPE ONE-TIME !PROGRAM-ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YES/NO) (YES/NO) The RHR system is connected to Complete ~ No Yes the RCS through several different lines, each containing valves that are normally closed. RCS leakage past these valves could potentially lead to saturated conditions within the piping, which could result in void formation. This would result in actuation of pressure switches and annunciation in the control room. Annunciator response procedures were revised to provide direction for identifying a temperature increase that could lead to saturated conditions within the piping, which could result in void formation. EGC has revised the procedure Complete No Yes associated with fill and vent of the HPCS system to include requirements to verify affected instrument lines have been properly filled. EGC has revised the procedure Complete ~ No Yes associated with fill and vent of the LPCS system to add a requirement to use valves 1 {2}E21-F027/F323 and 1(2)E21-FO29/F324 during system venting. EGC has revised the procedure Complete No Yes associated with fill and vent of the HPCS system to add a requirement to use valves 1(2)E22-FO26, 1(2)E22-FO12, and 1(2)E22-FO23 during system venting.
CHMENT15 Regulatory Commitments for LaSalle County Station COV 'TMENT as revisal the procedure ociated with fill and vent of the stem to add a requirement to use vent valves that were previously not used. EGC will revise periodic venting procedures for the GL 2008-01 subject systems to include hanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points. COMMITMENT TYPE PROGRAM- MATIC COMMITTED DATE OR "OUTAGE" Complete I No i Yes April 30, 2009 No Yes ATTACHMENT 16 Regulatory Commitments for Limerick Generating Station The following list identifies those actions committed to by Exelon Generation Company, LLC, (EGC) for Limerick Generating Station in this submittal. Any other actions discussed in the submittal represent intended or planned actions by EGC, are described only for information, and are not regulatory comm COMMITMENT TYPE: ONE-TIME I PROGRAM- ACTION MATIC 1 COMMITTED DATE COMMITMENT OR "OUTAGE" (YESINO) (YES/NO) Potential TS improvements are 180 days after NRC ~ Yes No being developed by the TSTF with ~ approval of the TSTF the goal of an NRC-approved TSTF Traveler Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. For the HPCI system, three new Prior to startup from the Yes No vents will be installed on each LGS next refueling outage for unit prior to startup from the next each LGS unit scheduled refueling outage for each unit.
CHMENT 1 6 Regulatory Commitments for Limerick Generating Station COMMITMENT TYPE ONE-TIME !PROGRAM ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YES/NO) {TES/NO) For the CS system, six new vents Prior to startup from the Yes F40 will be installed on each LGS unit next refueling outage for prior to startup from the next each LGS unit scheduled refueling outage for each unit. For the RHR system, one new vent Prior to startup from the Yes No will be installed on Unit 1, and two next refueling outage for new vents will be installed on Unit 2, each LGS unit prior to startup from the next scheduled refueling outage for each unit. EGC has revised procedure Complete No ~ Yes S52.1 A, "Core Spray Setup for Service Operation," to include requirements to verify affected instrument lines have been properly filled. EGC will revise periodic venting April 30,2009 No Yes procedures for the GL 2008-01 subject systems to include enhanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points.
Regulatory Comm ATTACHMENT 17 yster Creek Nuclear Generating Station The following list identifies those actions committed to by AmerGen Energy Company, PLC rGen) for Oyster Creek Nuclear Generating Station in this submittal. Any other actions sed in the submittal represent intended or planned actions by AmerGen, are described only for information, and are not regulatory commitments. COMMITMENT TYPE ONE-TIME !PROGRAM-ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YES/NO) (YES/NO) Potential TS improvements are 180 days after NRC Yes No being developed by the TSTF with ~ approval of the TSTF the goal of an NRC-approved TSTF Traveler Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. AmerGen is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. AmerGen will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF. AmerGen's review of the procedure Complete No Yes that governs venting of the SDC system identified there are vents installed on the system that are not currently used during venting activities. This procedure was revised to incorporate use of these vents during SDC system venting activities.
ATTACHMENT 17 Regulatory Commitments for Oyster Creek Nuclear Generating Station COMMITMENT TYPE ONE-TIME !PROGRAM-ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" I (YES/NO) (YES/NO) AmerGen will revise procedures October 24,2008 No Yes associated with fill and vent of the CS and Containment Spray systems to include requirements to verify affected instrument lines have been properly filled. AmerGen will revise the periodic April 30,2009 No Yes venting procedure for the CS system to include enhanced acceptance criteria and requirements to perform LlTs on a graded approach as part of venting verifications of accessible high points.
ATTACHMENT 18 Regulatory Commitments for Peach Bottom Atomic Power Station The following list identifies those actions committed to by Exelon Generation Company, LLC, (EGC) for Peach Bottom Atomic Power Station in this submittal. Any other actions discussed in the submittal represent intended or planned actions by EGC, are described only for informs and are not regulatory commitments. COMMITMENT TYPE . . ....... ...... . ....... .. T- ONE-TIME 1 PROGRAM- ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YES/NO) {YES/NO) Potential TS improvements are 180 days after NRC Yes ~ N o being developed by the TSTF with ~ approval of the TSTF the goal of an NRC-approved TSTF Traveler Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, I within 180 days following NRC approval of the TSTF. EGC will revise procedures February 27, 2009 ~ No Yes associated with fill and vent of the GIL 2008-01 subject systems to include requirements to verify affected instrument lines have been properly filled.
Regulatory Co ATTACHMENT 18 s for Peach Bottom Atomic Power Station COMMITMENT TYPE ONE-TIME 1 PROGRAM- ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YES/NO) (YES/NO) EGC will revise periodic venting April 30, 2009 ,o Yes procedures for the GL 2008-01 subject systems to include enhanced acceptance criteria and requirements to perform UTs on a graded approach as part of venting verifications of accessible high points.
ATTACHMENT 19 Regulatory Commitments for Quad Cities Nuclear Power Station The following list identifies those actions committed to by Exelon Generation Company, LLC, (EGC) for Quad Cities Nuclear Power Station in this submittal. Any other actions discussed in the submittal represent intended or planned actions by EGC, are described only for information, and are not regulatory commitments. COMMITMENT TYPE ONE-TIME 1PROGRAM-I ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YES/NO) (YES/NO) Potential TS improvements are 180 days after NRC Yes No I being developed by the TSTF with approval of the TSTF the goal of an NRC-approved TSTF Traveler Traveler for making changes to ~ individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. EGC is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues, EGC will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF EGC will revise fill and vent March 31, 2009 No Yes procedures as necessary to include requirements to verify affected instrument lines have been properly filled.
ATTACHMENT 19 Regulatory Commitments for Quad Cities Nuclear Power Station COMMITMENT TYPE ONE-TIME ~PROGRAM-ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YES/NO) ~ (YES/NO) EGC will revise periodic venting April 30, 2009 No Yes procedures for the GL 2008-01 subject systems to include enhanced acceptance criteria and i ~ ~ t requirements to perform UTs on a graded approach as part of venting verifications of accessible high points.
ATTACHMENT 20 Regulatory Commitments for Three Mile Island Nuclear Station The following list identifies those actions committed to by AmerGen Energy Company, LLC (AmerGen) for Three Mile Island Nuclear Station in this submittal. Any other actions discussed in the submittal represent intended or planned actions by AmerGen, are described only for information, and are not regulatory commitments. COMMITMENT TYPE ONE-TIME !PROGRAM-ACTION MATIC COMMITTED DATE COMMITMENT OR "OUTAGE" (YES/NO) (YES/NO) Potential TS improvements are 180 days after NRC Yes No being developed by the TSTF with approval of the TSTF the goal of an NRC-approved TSTF Traveler Traveler for making changes to individual licensee's TS related to the potential for adverse gas accumulation. The development of such a traveler hinges on the results of the evaluations of a large number of licensees to address the various plant designs. AmerGen is actively supporting the industry TSTF and NEI Gas Accumulation Management Team activities regarding resolution of generic TS issues. AmerGen will evaluate resolution of TS issues with respect to the elements contained in the TSTF, and submit a license amendment request, if deemed necessary based on this evaluation, within 180 days following NRC approval of the TSTF}}

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