3F0207-07, Pressurizer Dissimilar Welds and Reactor Coolant System Leakage Monitoring
| ML070570118 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 02/22/2007 |
| From: | Young D Progress Energy Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 3F0207-07 | |
| Download: ML070570118 (5) | |
Text
Progress Energy Crystal River Nuclear Plant Docket No. 50-302 Operating License No. DPR-72 February 22, 2007 3F0207-07 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
Pressurizer Dissimilar Welds and Reactor Coolant System Leakage Monitoring
Reference:
PEF to NRC letter, dated January 29, 2007, Inspection and Mitigation of Alloy 600/82/182 Pressurizer Butt Welds
Dear Sir:
By letter dated January 29, 2007, Florida Power Corporation, doing business as Progress Energy Florida Inc. (PEF), notified the NRC of actions planned for inspection and mitigation of Alloy 600/82/182 butt welds on pressurizer spray, surge and relief lines at Crystal River Unit 3 (CR-3). The letter also contained a description of the primary system leakage monitoring program in place at CR-3 at that time. Following a phone call with the NRC on February 15, 2007, CR-3 has worked to implement a revised enhanced primary leakage monitoring program. A description of this newly enhanced program is enclosed.
As discussed in the referenced letter, mitigation of pressurizer Alloy 600/82/182 butt welds per MRP-139 at CR-3 will be completed in Refuel Outage 15 (15R), which is scheduled for Fall 2007. The results of the inspection or mitigation of pressurizer Alloy 600/82/182 butt weld locations will be reported to the NRC within 60 days of startup from the outage during which they are performed.
The primary system leakage monitoring program described in this letter supersedes that contained in the letter dated January 29, 2007. The commritments listed in the letter dated January 29, 2007 remain valid and are being tracked by CR-3 for implementation. The primary system leakage monitoring program in place at CR-3 is being enhanced to agree with NRC expectations. The enhanced Reactor Coolant System (RCS) leakage monitoring program will consist of daily determination of the RCS leakage rate in addition to monitoring parameters such as Reactor Building sump level and Reactor Building radiation monitors.
The leakage determination process involves stabilization of the plant to minimize inaccuracies and calculation of Reactor Coolant System mass balance. The typical duration of this surveillance period is 2 to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The surveillance will be performned daily as part of the enhanced primary system leakage monitoring program when a sufficient period of steady state conditions is present. Steady state operating conditions include stable RCS pressure, temperature, power level and pressurizer and makeup tank levels.
If the surveillance is delayed due to changing plant conditions, the RCS leakage rate will be determined as soon as plant conditions permit.
If the daily RCS leakage measurement should increase by 0. 1 gpm above the mean leakage value and the leakage is sustained for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, with at least 0. 1 gpm not confirmed from sources other than the pressurizer nozzle welds, the Unit will be placed in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
Prior to restart, CR-3 will perform bare metal visual examinations on unmitigated Progress Energy Florida, Inc.
Crystal River Nuclear Plant 15760 W. Powerline Street
U.S. Nuclear Regulatory Commission Page 2 of 3 3F0207-07 pressurizer Alloy 600/82/182 butt welds. Daily values will be compared to a mean leakage value derived from previous RCS leakage surveillance results in order to reduce the effect of normal statistical variation.
An RCS leakage baseline is established from the first few stable RCS leakage surveillances performed following restart from a shutdown when the last bare metal visual inspection of unmitigated pressurizer butt welds was performed. If RCS leakage should increase by 0.25 gpm above the RCS leakage baseline and is sustained for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with 0.25 gpm not confirmed from sources other than the pressurizer nozzle welds, the Unit will be placed in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Prior to restart, CR-3 will perform bare metal visual examinations on unmitigated pressurizer Alloy 600/82/182 butt welds.
The enhanced leakrate monitoring program as described herein will be implemented by February 28, 2007 and will continue until mitigation of the pressurizer Alloy 600/82/182 welds, scheduled for Fall 2007.
Reactor Coolant System leakage is given a high priority by CR-3 management.
This sensitivity is reflected by taking actions beyond that of the procedural requirements on a routine basis.
Reactor Coolant System Unidentified Leakage information is included in daily plant information meetings and is a point of discussion at senior plant management meetings.
The enhanced guidance provides adequate assurance that structural integrity is maintained and that any primary system pressure boundary leakage is discovered in a timely manner.
This letter contains regulatory commitments as shown in the Attachment which supplement the commitments listed in the letter dated January 29, 2007. The NRC will be informed prior to any revision of the commitments contained in these letters.
CR-3 staff is available to meet with the NRC to discuss any of the information in this letter. If there are any questions regarding this submittal, please contact Mr. Paul Infanger, Supervisor, Licensing and Regulatory Programs at (352) 563-4796.
Sincerely, Dale E. Young Vice President Crystal River Nuclear Plant DEY/seb
Attachment:
List of Regulatory Commitments xc:
NRC Project Manager NRC Regional Office NRC Resident Inspector
U.S. Nuclear Regulatory Commission 3F0207-07 Page 3 of 3 STATE OF FLORIDA COUNTY OF CITRUS Dale E. Young states that he is the Vice President, Crystal River Nuclear Plant for Florida Power Corporation, doing business as Progress Energy Florida, Inc.; that he is authorized on the part of said company to sign and file with the Nuclear Regulatory Commission the information attached hereto; and that all such statements made and matters set forth therein are true and correct to the best of his knowledge, information, and belief.
Dale E. Young V Vice President Crystal River Nuclear Plant The foregoing document was acknowledged before me this o
~~day of 2007, by Dale E. Young.
Signature of Notary PubI LE EPLE State of Florida My COMSSO DPO 408R EXPIRES: Jul 8,2009 (Print, type, or stamp Commissioned Name of Notary Public)
Personally
~-Produced Know n 11'
-OR-Identification
PROGRESS ENERGY FLORIDA, INC.
CRYSTAL RIVER - UNIT 3 DOCKET NUMBER 50 -302 / LICENSE NUMBER DPR -72 Pressurizer Dissimilar Welds and Reactor Coolant System Leakage Monitoring Attachment List of Regulatory Commitments
U.S. Nuclear Regulatory Commission 3F0207-07 Attachment Page 1 of 1 List of Regulatory Commitments The following table identifies those actions committed to by Progress Energy Florida (PEF) in this document.
Any other actions discussed in the submittal represent intended or planned actions by PEF.
They are described to the NRC for the NRC's information and are not regulatory commitments. Please notify the Supervisor, Licensing and Regulatory Programs of any questions regarding this document or any associated regulatory commitments.
Commitment I
Due Date If RCS leakage should increase by 0. 1 gpm from the mean Beginning 2/28/07 until leakage value, and is sustained for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with at least mitigation of pressurizer Alloy
- 0. 1 gpm not confirmed from sources other than the 600/82/182 welds pressurizer nozzle welds, the Unit will be placed in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Prior to restart, CR-3 will perform bare metal visual examinations on unmitigated pressurizer Alloy 600/82/182 welds.
If RCS leakage should increase by 0.25 gpm above the Beginning 2/28/07 until RCS leakage baseline (established using RCS leakrate mitigation of pressurizer Alloy information from the few stable surveillance calculations 600/82/182 welds following the start of Mode 1 operation after the most recent bare metal visual examination) and is sustained for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with 0.25 gpm not confirmed from sources other than the pressurizer nozzle welds, the Unit will be placed in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
Prior to restart, CR-3 will perform bare metal visual examinations on unmitigated pressurizer Alloy 600/82/182 welds CR-3 will perform RCS leakrate monitoring on a daily Beginning 2/28/2007 until basis.
mitigation of pressurizer Alloy 600/82/182 welds CR-3 wil report details of inspection results of any Within 60 days of startup from the unmitigated pressurizer Alloy 600/82/182 weld exams and outage during which the any corrective or mitigative actions.
inspections are performed