ML022460160
| ML022460160 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 08/01/2002 |
| From: | Gallagher M AmerGen Energy Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 2130-02-20228 | |
| Download: ML022460160 (13) | |
Text
AmerGen AmerGen Energy Company, LLC www.exeloncorp.com An Exelon/British Energy Company 200 Exelon Way Suite 345 Kennett Square, PA 19348 1 OCFR50.55a 2130-02-20228 August 1,2002 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Oyster Creek Generating Station Facility Operating License No. DPR-1 6 NRC Docket No. 50-219
Subject:
Proposed Alternatives and Relief Request to the Requirements of 10CFR50.55a Concerning the Fourth Ten-Year Interval Inservice Inspection Program and Proposed Alternative to Containment Inspection Program
Reference:
Letter from M. P. Gallagher (AmerGen Energy Company, LLC) to U. S. Nuclear Regulatory Commission, dated April 26, 2002
Dear Sir/Madam:
Attached for your review and approval are proposed alternatives and a relief request in accordance with 10CFR50.55a, associated with the Fourth Ten-Year Interval Inservice Inspection (ISI) Program for Oyster Creek Generating Station (OCGS). Based on a start date of October 15, 2002, the OCGS ISI Program is required by 1 OCFR50.55a(g)(4)(ii) to comply with the requirements of the 1995 Edition (through 1996 Addenda) of the ASME, Section Xl Code. In the Reference 1 letter, a proposed alternative was also provided for the Fourth Ten-Year Interval concerning snubbers.
The third ten-year interval began on March 15, 1992, and will conclude on October 14, 2002. The fourth ten-year Interval will begin on October 15, 2002.
Also included as part of this request is a proposed alternative regarding the Containment Inspection Program at OCGS (OC-02-04). The OCGS Containment Inspection Program began on September 10, 1998, and will conclude on September 9, 2008.
We request your review and approval by August 1, 2003.
If you have any questions or require additional information, please do not hesitate to contact us.
Very truly yours, Michael P. Gallagher Director, Licensing & Regulatory Affairs Mid-Atlantic Regional Operating Group Attachment -Oyster Creek Generating Station Proposed Alternatives and Relief Request cc:
H. J. Miller, Administrator, USNRC, Region I (w/attachment)
L. Dudes, USNRC Senior Resident Inspector, OCGS (w/attachment)
P. Tam, Senior Project Manager, USNRC (w/attachment)
File No. 02064
ATTACHMENT OYSTER CREEK GENERATING STATION RELIEF REQUEST OC-02-02 ALTERNATIVES OC-02-01 OC-02-03 OC-02-05 CONTAINMENT ALTERNATIVE OC-02-04
Oyster Creek Generating Station 2130-02-20228 August 1,2002 Page 1 of 11 AmerGen Energy Company Oyster Creek Generating Station Fourth 10-Year Interval Request for Relief OC-02-01 COMPONENT IDENTIFICATION Code Class:
Class 1 and Class 2
Reference:
ASME Section XI, 1995 Edition, 1996 Addenda, Tables IWB 2500-1 and IWC-2500-1 Examination Categories:
B-J, C-F-1 Item Numbers:
B9.10, and C5.10
==
Description:==
Alternative requirements to the surface examination requirements for circumferential welds Component Numbers:
All welds examined per the requirements of BWRVIP-75 CODE REQUIREMENTS ASME Section XI, 1995 Edition, 1996 Addenda, Table IWB-2500-1, Examination Category B-J, Pressure Retaining Welds in Piping, Item B9.1 0 and Table IWC-2500-1, Examination Category C-F-i, Pressure Retaining Welds in Austenitic Stainless Steel or High Alloy Piping, Item C5.10 requires a surface and volumetric examination.
CODE REQUIREMENTS FROM WHICH AN ALTERNATIVE IS REQUESTED Relief is requested from the ASME Section XI required surface examination specified in Table IWB-2500 1, Examination Category B-J, Pressure Retaining Welds in Piping, Item B9.10 and Table IWC-2500-1, Examination Category C-F-i, Pressure Retaining Welds in Austenitic Stainless Steel or High Alloy Piping, Item C5.10 for those welds which are volumetrically examined per the requirements of BWRVIP-75.
BASIS FOR ALTERNATIVE Pursuant to 10 CFR 50.55a(a)(3)(i), relief is requested on the basis that the proposed alternative would provide an acceptable level of quality and safety.
During 20 years of Section XI required surface examinations, no service induced OD cracks have been discovered on any stainless steel weld at Oyster Creek. A positive result of the investigations performed on BWR piping is that no significant mode of degradation other than IGSCC has been noted. This means that inspections can focus on those approaches that are best suited for detecting and evaluating IGSCC.
Service-induced stresses on most BWR piping are relatively low. The source of the high stress primarily responsible for IGSCC is the high tensile stress on the inside of the pipe caused by normal welding practice.
Liquid penetrant testing is very radiation dose intensive due to pre and post cleaning and dwell times associated with penetrant and developer application. The process also creates substantial amounts of mixed waste. Oyster Creek has concurred with recommendations in Generic Letter 88-01 and NUREG-
Oyster Creek Generating Station 2130-02-20228 August 1, 2002 Page 2 of 11 0313 and now implements BWRVIP-75 which focus on approaches which are best suited for detecting and evaluating IGSCC. Continuing with the ASME Section Xl surface examinations for the welds in question results in additional exposure to personnel and creation of mixed waste with no increase in safety or quality.
PROPOSED ALTERNATIVE PROVISIONS The welds identified as being under both the requirements of: 1) ASME Section Xl, Examination Category B-J, Item B9.10, and Examination Category C-F-i, Item C5.10; and 2) BWRVP-75 shall be ultrasonically examined in accordance with requirements of Section XI and BWRVP-75.
AmerGen will continue to meet the ASME Section Xl scheduling, recording, and summary report preparation requirements associated with the referenced components.
PERIOD FOR WHICH AN ALTERNATIVE IS REQUESTED This alternative is for the fourth inspection interval at Oyster Creek Generating Station, which is scheduled to begin on October 15, 2002.
Oyster Creek Generating Station 2130-02-20228 August 1, 2002 Page 3 of 11 AmerGen Energy Company Oyster Creek Generating Station Fourth 10-Year Interval Request for Relief OC-02-02 COMPONENT IDENTIFICATION Code Class:
Class 1
Reference:
ASME,Section XI, 1995 Edition, 1996 Addenda, Table IWB-2500-1 Examination Categories:
B-K Item Numbers:
B10.10
==
Description:==
Alternative requirements to examination area requirements of Figure IWB 2500-13, and Note 2 of Table IWB-2500-1, Category B-K, extent of examination which requires essentially 100% of the length of the attachment weld at each attachment subject to examination.
Component Numbers:
Reactor Vessel Support Skirt Weld 1-569 CODE REQUIREMENTS ASME Section XI, 1995 Edition, 1996 Addenda, Table IWB-2500-1, Examination Category B-K, Welded Attachments for Vessels, Piping, Pumps, and Valves, Item B10.10, requires that welded attachments to pressure vessels be subject to a surface examination. Table IWB-2500-1 references Figures IWB-2500 13, IWB-2500-14, and IWB-2500-15 for the determination of the applicable surface areas requiring examination. Figure IWB-2500-13 is the applicable figure for the Oyster Creek Vessel skirt design. In addition, the extent of the examination per Note 2 includes essentially 100% of the length of the attachment weld at each attachment subject to examination.
CODE REQUIREMENTS FROM WHICH RELIEF IS REQUESTED Relief is requested from the ASME Section XI required surface areas (examination areas A-B and C-D) as shown in Figure IWB-2500-13 (Attachment 1) and extent of examination as stated in Note 2 of Table IWB 2500-1, Examination Category B-K, Item B10.10.
BASIS FOR RELIEF Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested on the basis that the Code requirements to examine essentially 100% of the surface areas is impractical due to physical obstructions and geometric interference.
Control rod drive housings and instrumentation penetrations restrict the examination of area C-D as required by Figure IWB-2500-13. The physical location of the drives and instrumentation penetration and the design of the vessel skirt prohibit access to area C-D. Area A-B as shown in Figure IWB-2500-13 remains accessible for surface examination to the extent required by the Code.
In addition, Oyster Creek's nondestructive examination group pursued the use of an alternative ultrasonic examination method in lieu of the surface examination for area C-D. As a result of this review which
Oyster Creek Generating Station 2130-02-20228 August 1,2002 Page 4 of 11 considered the unique configuration of the Oyster Creek vessel skirt design, it was concluded that ultrasonics would not provide Code examination coverage.
Compliance with the applicable Code requirements would require redesigning and modifying the reactor pressure vessel support skirt. The modification of the vessel support skirt would result in significant radiological exposure and significant engineering and construction expense without a compensating increase in the level of quality and safety.
PROPOSED RELIEF PROVISIONS As an alternative to the Code requirement to perform a surface examination of areas A-B and C-D AmerGen proposes to perform the following:
Perform a surface examination of area A-B as required by Table IWB-2500-1, Category B-K Perform a VT-3 visual examination of the support skirt IWB boundary as shown in Figure IWB-2500-13 for any support member deformation.
PERIOD FOR WHICH RELIEF IS REQUESTED This relief is for the fourth inspection interval at Oyster Creek Generating Station, which is scheduled to begin on October 15, 2002.
Oyster Creek Generating Station 2130-02-20228 August 1,2002 Page 5 of 11 ATTACHMENT 1
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Oyster Creek Generating Station 2130-02-20228 August 1,2002 Page 6 of 11 AmerGen Energy Company Oyster Creek Generating Station Fourth 10-Year Interval Request for Relief OC-02-03 COMPONENT IDENTIFICATION Code Class:
Class 3
Reference:
ASME,Section XI, 1995 Edition, 1996 Addenda, Table IWD-2500-1 Examination Categories:
D-B Item Numbers:
D2.20, D2.40, D2.60, and D2.80
==
Description:==
Alternative requirements to the hydrostatic tests specified in Table IWD-2500 1
Component Numbers:
All Class 3 pressure retaining components CODE REQUIREMENTS ASME,Section XI 1995 Edition, 1996 Addenda, Table IWD-2500-1, Examination Category D-B, Items D2.20, D2.40, D2.60, D2.80 requires a system hydrostatic test, VT-2 visual examination, each inspection interval per the requirements of IWD-5222.
CODE REQUIREMENTS FROM WHICH AN ALTERNATIVE IS REQUESTED An alternative is requested from performing the system hydrostatic tests required by Table IWD-2500-1, Examination Category D-B, Items D2.20, D2.40, D2.60, and D2.80.
BASIS FOR ALTERNATIVE Pursuant to 10 CFR 50.55a(a)(3)(i), an alternative is requested on the basis that the proposed alternative provide an acceptable level of quality and safety.
ASME Section XI Boiler and Pressure Vessel Code Committees and working groups have over recent years reviewed the requirements for hydrostatic testing. Code committee consensus acknowledged that the small increase in system pressure and limited challenge to pressure boundary integrity associated with a hydrostatic test versus the pressure for the system leakage test did not offset the hardship imposed by the performance of the hydrostatic test. As a result, Code Case N-498-1 was published and endorsed by the NRC in Regulatory Guide 1.147.Section XI was revised in the 1995 Edition, 1996 Addenda, and the requirements of Code Case N-498-1 (i.e. system leakage tests replacing hydrostatic tests) were incorporated into Tables IWB-2500-1, Category B-P and IWC-2500-1, Category C-H. However, the pressure test requirements for Class 3 stated in N-498-1 were omitted in the Code revision as shown by Table IWD-2500-1. Category D-B still requires a system hydrostatic test. The Section XI Working Group Pressure Testing has recognized this omission and is taking action to resolve this issue through the Section XI Main Committee.
The ASME Code has subsequently approved Code Case N-498-4 for use regarding pressure testing of Class 1, Class 2, and Class 3 systems. Code Case N-498-4 allows for the alternative use of a system leakage test in lieu of hydrostatic testing for Class 3 systems. However, the Code Case does not require any hold time prior to the performance of the VT-2 examination. Contrary to the Case, Oyster Creek would impose a hold time as follows:
Oyster Creek Generating Station 2130-02-20228 August 1, 2002 Page 7 of 11 For insulated systems, a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time would be required at system operating pressure and temperature.
For non-insulated systems a hold time of 10 minutes would be required at system operating pressure and temperature.
PROPOSED ALTERNATIVE PROVISIONS As an alternative to the Code requirements for Class 3 systems of Table IWD-2500-1, Examination Category D-B, Items D2.20, D2.40, D2.60, and D2.80, AmerGen will invoke the requirements of Code Case N-498-4 for system leakage testing.
The following hold times for the pressure test would be imposed in addition to the requirements of Code Case N-498-4:
For insulated systems, a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time would be required at system operating pressure and temperature.
For non-insulated systems a hold time of 10 minutes would be required at system operating pressure and temperature.
PERIOD FOR WHICH ALTERNATIVE IS REQUESTED This relief is for the fourth inspection interval at Oyster Creek Generating Station which is scheduled to begin on October 15, 2002.
Oyster Creek Generating Station 2130-02-20228 August 1,2002 Page 8 of 11 AmerGen Energy Company Oyster Creek Nuclear Generating Station Fourth 10-Year Interval Request for Relief OC-02-05 COMPONENT IDENTIFICATION Code Class:
All
Reference:
1995 Edition with 1996 Addenda, Appendix VII, VII-4240 Examination Categories:
All Item Numbers:
All
==
Description:==
Alternative Requirements to Appendix VII of Section Xl (1995 Edition with the 1996 Addenda), VII-4240, "Annual Training" Component Numbers:
All Components Subject to Ultrasonic Examination CODE REQUIREMENTS The 1995 Edition, with the 1996 Addenda of ASME Section Xl, Subarticle VII-4240, requires a minimum of 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> annual training.
10 CFR 50.55a(b)(2)(xiv) requires that all personnel qualified for performing ultrasonic examinations in accordance with Appendix VIII shall receive 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of annual hands-on training on specimens that contain cracks. The training must be completed no earlier than 6 months prior to performing ultrasonic examinations at a licensee's facility.
CODE REQUIREMENTS FROM WHICH AN ALTERNATIVE IS REQUESTED An alternative is requested in accordance with 10 CFR 50.55a(a)(3)(i) to the provisions of Subarticle VII 4240, "Annual Training."
BASIS FOR ALTERNATIVE This alternative was previously approved for the Third Ten-Year Interval for the Oyster Creek Generating Station in a Safety Evaluation Report dated December 5, 2001 (Letter from L. Raghavan (U. S. Nuclear Regulatory Commission) to 0. D. Kingsley (Exelon Nuclear)).
10 CFR 50.55a was amended in the Federal Register (Volume 64, No. 183 dated September 22, 1999) to require the 1995 Edition, with the 1996 Addenda of Section Xl for Appendix VIII qualification requirements.
This also imposes the requirements of Appendix VII of the 1995 Edition, with the 1996 Addenda of Section Xl. This includes Subarticle VII-4240, which requires a minimum of 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> of annual training.
10 CFR 50.55a(b)(2)(xiv) requires that all personnel qualified for performing ultrasonic examinations in accordance with Appendix VIII shall receive 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of annual hands-on training on specimens that contain cracks. This training must be taken no earlier than 6 months prior to performing examinations at a licensee's facility.
Paragraph 2.4.1.1.1 in the Federal Register notice for the final rule (64 Fed. Reg. 51370, 1999) contained the following statement:
Oyster Creek Generating Station 2130-02-20228 August 1,2002 Page 9 of 11 The NRC had determined that this requirement was inadequate for two reasons. The first reason was that the training does not require laboratory work and examination of flawed specimens. Signals can be difficult to interpret and, as detailed in the regulatory analysis for this rulemaking, experience and studies indicate that the examiner must practice on a frequent basis to maintain the capability for proper interpretation.
The second reason is related to the length of training and its frequency. Studies have shown that the examiner's capability begins to diminish within approximately 6 months if skills are not maintained. Thus, the NRC had determined that 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> of annual training is not sufficient practice to maintain skills, and that the examiner must practice on a more frequent basis to maintain proper skill level. The PDI program has adopted a requirement for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of training, but it is required to be hands-on practice. In addition, the training must be taken no earlier than 6 months prior to performing examinations at a licensee's facility. PDI believes that 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> will be acceptable relative to an examiner's abilities in this highly specialized skill area because personnel can gain knowledge of new developments, material failure modes, and other pertinent technical topics through other means. Thus, the NRC has decided to adopt in the Final Rule the PDI position on this matter. These changes are reflected in Sec. 10 CFR 50.55a(b)(2)(xiv) of the final rule.
Implementation of the requirements contained in ASME Section Xl and 10 CFR 50.55a will result in redundant training programs. The use of the regulatory requirements in lieu of additional requirements will simplify record keeping, satisfy needs for maintaining skills, and provide an acceptable level of quality and safety.
PROPOSED ALTERNATIVE PROVISIONS Annual ultrasonic training shall be conducted in accordance with 10 CFR 50.55a(b)(2)(xiv) in lieu of Section XI, Appendix VII, Subarticle VII-4240.
PERIOD FOR WHICH ALTERNATIVE IS REQUESTED This alternative is for the fourth inspection interval at Oyster Creek Generating Station, which is scheduled to begin on October 15, 2002.
Oyster Creek Generating Station 2130-02-20228 August 1, 2002 Page 10 of 11 AmerGen Energy Company Oyster Creek Generating Station Containment Inspection Program Request for Relief OC-02-04 COMPONENT IDENTIFICATION Code Class:
Class MC
Reference:
ASME,Section XI, 1992 Edition, 1992 Addenda, Table IWE-2500-1 Examination Categories:
E-G Item Numbers:
E8.10 and E.8.11
==
Description:==
Alternative requirements to the visual (VT-1) and torque and tension testing requirements specified in Table IWE-2500-1 Component Numbers:
All Class MC bolting CODE REQUIREMENTS ASME Section XI, 1992 Edition, 1992 Addenda, Table IWE-2500-1, Examination Category E-G, Pressure Retaining Bolting, Item E8.10, requires that Class MC bolted connections be subject to a VT-1 visual examination.
ASME Section XI, 1992 Edition, 1992 Addenda, Table IWE-2500-1, Examination Category E-G, Pressure Retaining Bolting, Item E8.20, requires that Class MC bolted connections which have not been disassembled and reassembled during the inspection interval be subject to torque or tension testing.
CODE REQUIREMENTS FROM WHICH AN ALTERNATIVE IS REQUESTED Relief is requested from the Code required VT-1 visual examinations specified in Table IWE-2500-1, Examination Category E-G, Item E8.1 0, and the Code required torque or tension testing specified in Table IWE-2500-1, Examination Category E-G, Item E8.20.
BASIS FOR ALTERNATIVE Pursuant to 10 CFR 50.55a(a)(3)(ii), an alternative is requested for the Oyster Creek Generating Station on the basis that compliance with the specified Code requirements would result in hardship or unusual difficulty without a compensating increase in the level of safety and quality.
The reexamination of bolted connections that are already examined as part of Examination Category E-A, and tested in accordance with 10 CFR 50, Appendix J, unnecessarily increases the number of inservice examinations and the associated radiation exposure to personnel.
At OCGS, containment surfaces, including bolted connections, are already subject to visual examination in accordance with Table IWE-2500-1, Examination Category E-A. Additionally, bolted connections in containment are subject to the performance of 10 CFR 50, Appendix J testing.
In addition to the VT-1 visual examination of bolted connections, the 1992 Edition, 1992 Addenda,Section XI, Examination Category E-G, Item E8.20 requires that bolt torque or tension testing be performed on bolted connections that have not been disassembled and reassembled during the inspection interval.
Oyster Creek Generating Station 2130-02-20228 August 1, 2002 Page 11 of 11 Determination of the torque or tension value would require that the bolting be un-torqued and then re torqued or retensioned. The performance of a 10 CFR 50, Appendix J, Type B test proves that the bolt torque or tension remains adequate to provide a leak rate that is within acceptable limits. The torque or tension value of bolting only becomes an issue if the leak rate is excessive. Once a bolt is torqued or tensioned, it is not subject to dynamic loading that could cause it to experience significant change.
Appendix J testing and visual inspection is adequate to demonstrate that the design function is met.
Torque or tension testing is not required on any other ASME Section Xl, Class 1, 2, or 3 bolted connections or supports as part of the inservice inspection program.
As a result, Examination Category E-G has been eliminated from Table IWE-2500-1 in the 1998 Edition of ASME Section Xl and bolting examinations incorporated into the examinations required to be performed in Examination Category E-A.
PROPOSED ALTERNATIVE PROVISIONS The adequacy of Class MC containment pressure retaining bolted connections shall be verified by the following:
- 1)
Exposed surfaces of bolted connections shall be visually examined during the conduct of examinations performed in accordance with the requirements of Table IWE-2500-1, Examination Category E-A, Containment Surfaces, using VT-3 certified inspectors. These examinations shall be evaluated in accordance with the requirements of IWE-3510.
Deficiencies recorded during the visual examinations will subsequently be VT-1 (visually) examined and dispositioned by a responsible engineer.
- 2)
Bolted connections shall meet the pressure test requirements of 10 CFR 50, Appendix J.
PERIOD FOR WHICH ALTERNATIVE IS REQUESTED Relief is requested for the first inspection interval for containment inspections required by ASME B&PV Code Section XI, 1992 Edition, 1992 Addenda at Oyster Creek Generating Station. The OCGS Containment Inspection Program began on September 10, 1998, and will conclude on September 9, 2008.