ML111651184
| ML111651184 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 06/16/2011 |
| From: | John Hughey Plant Licensing Branch 1 |
| To: | Pacilio M Exelon Nuclear |
| Hughey J, NRR/DORL, 301-415-3204 | |
| References | |
| TAC MD7860, TAC MD7861, GL-08-001 | |
| Download: ML111651184 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 16, 2011 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
PEACH BOTTOM ATOMIC POWER STATION, UNIT NOS. 2 AND 3 CLOSEOUT OF GENERIC LETTER 2008-01 "MANAGING GAS ACCUMULATION IN EMERGENCY CORE COOLING, DECAY HEAT REMOVAL, AND CONTAINMENT SPRAY SYSTEMS" (TAC NOS. MD7860 AND MD7861)
Dear Mr. Pacilio:
On January 11, 2008, the U.S. Nuclear Regulatory Commission (!\\IRC) issued Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072910759). The stated purpose of GL 2008-01 was: (a) to request addressees to submit information to demonstrate that the 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; and, (b) to collect the requested information to determine if additional regulatory action is required.
GL 2008-01 requested that licensees provide the following information within 9 months of the date of the GL:
(a)
A description of the results of evaluations that were performed pursuant to requested actions specified in the GL. The description was to provide sufficient information to demonstrate that you are or will be in compliance with the quality assurance criteria in Sections III, V, XI, XVI, and XVII of Appendix B to 10 CFR Part 50 and the licensing basis and operating license as those requirements apply to the subject systems; (b)
A description of all corrective actions, including plant, programmatic, procedure, and licensing basis modifications that you determined were necessary to assure compliance with these regulations; and, (c)
A statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule.
By letters dated April 11,2008 (ADAMS Accession No. ML081020758), October 14,2008 (ADAMS Accession No. ML082880706), January 16, 2009 (ADAMS Accession No. ML090160291), November 10, 2009 (ADAMS Accession No. ML093170019), January 4, 2010 (ADAMS Accession No. ML100050040), and December 15, 2010 (ADAMS Accession No. ML103490536), Exelon Generation Company, LLC (Exelon, the licensee), provided responses to Generic Letter 2008-01.
M. Pacilio The November 10, 2009, letter provided a response to NRC staff requests for additional information, which are discussed below:
Request 1 asked the licensee to clarify which Residual Heat Removal functions and subsystems are within the scope of the GL review and which ones were excluded. The licensee provided a response describing the functions and subsystems included and a list of those portions of the system that were excluded. The NRC staff finds that the function/subsystem list provided, with the identified excluded portions, is responsive to the GL.
Request 2 asked the licensee to describe how Technical Specification Surveillance Requirements and other procedures assure that Emergency Core Cooling System (ECCS) pipe voiding does not inhibit operability. The licensee described optimized station procedures for systems, monitoring and trending of the suppression pool cooling mode, and detailed changes to procedures to reduce the possible occurrence of voids.
The NRC staff finds that the procedures and system operation descriptions provided by the licensee are responsive to the GL.
Request 3 asked the licensee to summarize the procedure and methodology used to perform evaluations of the data collected and the input assumptions used when determining the impact of voids on system operability and what additional steps are taken to address any voiding. The licensee responded that an Issue Report is initiated in the Corrective Action Program (CAP) if gas is identified and an operability determination is completed to determine whether the system in question would perform its safety function. The licensee also stated that ultrasonic testing (UT) is utilized to determine void volumes. The NRC staff finds that the licensee's description of the methods used for void identification and evaluation are responsive to the GL.
Request 4 asked the licensee to provide information pertaining to system drawing reviews and system walk-downs and the assessment of gas accumulation susceptibility.
The licensee's response included criteria for UT examination, the CAP process, and a description of the licensee's involvement in industry gas management initiatives. The NRC staff finds that the information provided by the licensee regarding system walk down and drawing reviews to identify and evaluate gas voiding susceptibility is responsive to the GL.
Request 5 asked the licensee to provide additional information on ECCS void surveillance methods. The licensee's response included a discussion of the use of Froude numbers attributed to system flow rates to assess the susceptibility for voiding and revisions to fill and vent procedures to add the use of UT examinations. The NRC staff finds that the information provided by the licensee is responsive to the GL.
M. Pacilio
- 3 Request 6 asked the licensee to provide more information on their fill and vent procedures. The licensee responded that they rely upon their staff to control system configuration during operations and maintenance evolutions and to initiate incident reports in the CAP for human performance errors. Changes to work packages require approval of Operations shift management and are controlled by administrative controls.
The NRC staff finds that the licensee's description of administrative measures and operating procedures to ensure that systems are sufficiently full of water prior to their return to service is responsive to the GL.
Request 7 asked the licensee to provide a brief overview of training with respect to issues identified in GL 2008-01. The licensee responded that an assessment of training needs is required for all procedure changes. The fill and vent procedure changes were minor and assessed as enhancements that did not require training. Training of personnel performing UT inspections is accomplished in accordance with corporate procedures. The NRC staff finds that the information provided by the licensee is responsive to the GL.
The NRC staff has determined that the Peach Bottom CAP is used to document gas intrusion/accumulation issues as potential nonconforming conditions. The CAP process identifies relevant plant equipment for evaluation and potential impact on operability and reportability. If gas intrusion is found, a CAP incident report is initiated and operability of the system in question is determined. The NRC staff finds that Peach Bottom is effectively using the station's CAP process to demonstrate current operability.
The NRC staff has concluded that the licensee has acceptably demonstrated "that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified," as stated in Generic Letter 2008-01. The NRC is continuing to engage with stakeholders regarding the creation of durable guidance for Gas Management which may require additional actions by the licensee beyond the scope of Generic Letter 2008-01.
Please contact me at 301-415-3204, if you have any questions.
John Hughey, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-277 and 50-278 cc: Distribution via Listserv
M. Pacilio
- 3 Request 6 asked the licensee to provide more information on their fill and vent procedures. The licensee responded that they rely upon their staff to control system configuration during operations and maintenance evolutions and to initiate incident reports in the CAP for human performance errors. Changes to work packages require approval of Operations shift management and are controlled by administrative controls.
The NRC staff finds that the licensee's description of administrative measures and operating procedures to ensure that systems are sufficiently full of water prior to their return to service is responsive to the GL.
Request 7 asked the licensee to provide a brief overview of training with respect to issues identified in GL 2008-01. The licensee responded that an assessment of training needs is required for all procedure changes. The fill and vent procedure changes were minor and assessed as enhancements that did not require training. Training of personnel performing UT inspections is accomplished in accordance with corporate procedures. The NRC staff finds that the information provided by the licensee is responsive to the GL.
The NRC staff has determined that the Peach Bottom CAP is used to document gas intrusion/accumulation issues as potential nonconforming conditions. The CAP process identifies relevant plant equipment for evaluation and potential impact on operability and reportability. If gas intrusion is found, a CAP incident report is initiated and operability of the system in question is determined. The NRC staff finds that Peach Bottom is effectively using the station's CAP process to demonstrate current operability.
The NRC staff has concluded that the licensee has acceptably demonstrated "that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified," as stated in Generic Letter 2008-01. The NRC is continuing to engage with stakeholders regarding the creation of durable guidance for Gas Management which may require additional actions by the licensee beyond the scope of Generic Letter 2008-01.
Please contact me at 301-415-3204, if you have any questions.
Sincerely,
/raJ John Hughey, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-277 and 50-278 cc: Distribution via Listserv DISTRIBUTION:
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