ML18068A446
| ML18068A446 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 10/08/1998 |
| From: | Haskell N CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9810140287 | |
| Download: ML18068A446 (21) | |
Text
r A CMS Energy Company October 8, 1998 U.S. Nuclear Regulatory Commission A TIN: Document Control Desk Washington, DC 20555 Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, Ml 49043 DOCKET 50-255 - LICENSE DPR PALISADES PLANT
{el: 676 764 2276 Fax: 616 764 2490 Na\\iian L. Hasllall Director, Licensing INSERVICE TESTING RELIEF REQUESTS RELATING TO ASME SECTION XI, SUBSECTIONS IWE AND IWL In a final rule issued on August 8, 1996, 10 CFR 50.55a was revised to require implementation of the 1992 Edition (with 1992 Addenda), Subsections IWE and IWL, of American Society of Mechanical Engineers (ASME)Section XI, lnservice Inspection of Nuclear Power Plant Components. These new requirements must be implemented by September 9, 2001.
A review of Subsections IWE and IWL has identified the need to request relief from several of the requirements. The attachment to this letter contains those relief requests. In order to meet the required implementation date, some of the new requirements would need to be completed during the 1999 refueling outage. As a result, approval of these relief requests is requested by April 9, 1999.
For your information, these relief requests are similar to those previously submitted by the Davis-Besse and Calvert Cliffs Nuclear Power Plants.
9810140287 981008
-~DR ADOCK 0500~~5-,
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SUMMARY
OF COMMITMENTS This letter contains no new commitments and no revisions to existing commitments.
athan L. Haskell irector, Licensing CC Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades Attachment 2
ATTACHMENT CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET 50-255 INSERVICE TESTING RELIEF REQUESTS RELATING TO ASME SECTION XI, SUBSECTIONS IWE AND IWL
CONTAINMENT RELIEF REQUEST N0.1 System for Which Relief is Requested:
Containment Inspection Program under the ASME Section XI Code Subsection IWE 1992 Edition with the 1992 Addenda.
Code Requirement:
The 1992 Editiqn of Section XI with the 1992 Addenda, Table IWE-2500-1 Category E-A, Item E1.12, requires VT-3 examination of accessible areas of the containment vessel.
Code Requirement From Which Relief is Requested:
In accordance with 1 O CFR 50.55a(a)(3)(i), relief i's requested from performing the above Code required examinations since they are a duplication of examinations required to be conducted periodically during the 10 year inspection interval.
Basis For Relief:
In accordance with 10 CFR 50.55a(a)(3)(i); relief is requested from performing the above Code required examination since the proposed alternative would provide an adequate level of safety while eliminating unnecessary redundancy and reducing personnel dose.
The NRC Final Rule issued on August 8, 1996, revised 10 CFR 50.55a to require implementation of the containment inspection requirements of Subsection IWE of the 1992 Edition of the ASME Section XI Code with the 1992 Addenda. Table IWE-2500-1 Category E-A Item E1.11 requires General Visual examination of accessible surfaces prior to each Type A leak rate test. This requirement was expanded by 1 O* CFR 50.55a(b)(2)(x)(E) to require that the General Visual examination be performed
... each period. Performing both a VT-3 ar:id a General Visual. examination is redundant.
Requiring a VT-3 examination in addition to the General Visual Examination requires NOE certified examination personnel in addition to the structural engineering inspectors without a compensating increase in quality or safety.
The Palisades containment inspection program is described in Engineering Manual Rrocedure EM-09-12, "Containment lns~rvice lnspe.~tion,_Testing and Aging Management Program." The General Visual examination of containment surfaces shall be under the direction of a registered Professional Engineer or an individual knowledgeable in the requirements for design, inservice inspection, and testing of Class MC and metallic liners of Class CC components. The examiner shall have visual acuity 1
CONTAINMENT RELIEF REQUEST N0.1 sufficient to detect evidence of degradation that may affect either the containment structural integrity or leak tightness.
A certified VT-3 examiner shall be capable of detecting the degradation described in IWE-3510.2 and IWE-3510.3. The VT-3 examiner will operate under the direction of the Professional Engineer, and, in essence, both individuals shall be capable of detecting the same types of degradation. The VT-3 examination is redundant to the General Visual examination.
ASME Code,Section XI, Subsection IWE Commentary, IWE Personnel Qualification states, "Because VT-1 and VT-3 visual examination requirements have been deleted and replaced by the detailed and General Visual examinations in Subsection IWE, NOE personnel need not perform these examinations. The general and detailed visual examinations may be performed by engineering personnel. The conduct of these visual
- examinations shall be directed by the RPE or other knowledgeable individual." This provides further justification for deletion of the VT-3 visual examination requirement and the associated burden of maintaining personnel certifications and redundant NOE program and procedures. The statement suggests that the authors of Subsection IWE did not intend to require both General Visual examination and VT-3 examinations.
Personnel dose would effectively be doubled if both a General Visual examination and VT-3 visual examination must be performed. During the containment coatings and IWE engineering walkdowns conducted during the 1998 refueling outage, Palisades personnel accrued a total dose of 384 mR. This walkdown was used to validate engineering data necessary for the development of the Palisades IWE program.. Based on this work the estimated dose for either a General Visual or VT-3 examination is 100 mR. Therefore, by deleting the redundant VT-3 visual examination, personnel dose will be reduced by approximately 100 mR each inspection period.
Alternate Examination:
Palisades will perform the Gen~ral Visual examination of ASME Section XI, Subsection IWE, in lieu of the VT-3 examinations.
2
CONTAINMENT RELIEF REQUEST NO. 1 Implementation Schedule:
First inspection interval for IWE.
Status:
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(i) from performing the Code required examination since compliance with the proposed alternative will provide an adequate level of quality and safety. Prior NRC approval is required before implementing the proposed alternative.
3
CONTAINMENT RELIEF REQUEST NO. 2 System for Which Relief is Requested:
Class MC Containment component bolting subject to ASME Section XI Code, Subsection IWE, 1992 Edition with the 1992 Addenda.
Penetration Service Description Drawing MZ-19 Personnel Airlock M-232-1 MZ-50 Emergency Airlock M-232-2 MZ-51 Equipment Hatch M-232-2 Code Requirement:
ASME Section XI, 1992 Edition, 1992 Addenda, Table IWE-2500-1 Category E-G, requires in Item EB.20 that bolt torque or tension tests be conducted on 100% of bolts on containment pressure boundary, during each inspection interval.
Code Requirement From Which Relief is Requested:
Relief is requested for ASME Section XI, 1992 Edition with 1992 Addenda, Table IWE-2500-1, Examination Category E-G, "Pressure Retaining Bolting," item 8.20.
Specifically, relief is requested from the requirement to perform bolt torque or tension testing on bolted connections that have not been disassembled and reassembled
- during the inspection interval.
Basis For Relief:
In accordance with 1 OCFR50.55a(a)(3)(i), relief is requested from performing the above Code required examination since the proposed alternatives would provide an acceptable level of quality and safety.
Bolt torque or tension testing is required on bolted connections that have not been disassembled and reassembled during the inspection interval.. Determination of the torque or tension value requires the bolting be detorqued or detensioned and retorqued
_or retensioned. This is considered a maintenance activity in accordance with Palisades Administrative-Procedure 5.01, "Processing Work Requests/Work Orders."
Table IWE-2500-1, Item E8.10 requires VT-1 examination of 100% of each bolted connection during each inspection interval to detect signs of deterioration. These 1
CONTAINMENT RELIEF REQUEST NO. 2 examinations do not require disassembly of the connection solely for the performance of surveillance activities.
Appendix J leak rate testing is also conducted during each inspection interval to assure leak tightness of the containment and penetrations. The Appendix J, ILRT performed once per 10-year interval, applies pressure in a manner which increases the sealing capability of the affected bolted connections. Additionally, local leak rate testing confirms satisfactory performance of individual penetrations. These facts minimize the importance of bolt torque or tension for these connections. These activities have demonstrated their acceptability in assuring structural integrity or leak tightness and, thus, adequate torque or tension of containment bolted connections.
Torque or tension testing is not required on any other ASME Section XI, Class 1, 2 or 3 bolted connection or their supports as part of the inservice inspection program.
Alternate Examination:
- The General Visual examination required by Table IWE-2500-1 Category E-A, Item E1.11, conducted during each inspection period, shall be pei"formed to detect signs of deterioration in bolted connections that could affect leak tightness. This General Visual examination shall be coordinated with the Engineering Manual Procedure EM-09-10, *
"Palisades ILRT/LLRT Program," Appendix J, pre-ILRT examination.
In addition, Table IWE-2500-1 Category E'"G, Item E8.10 requires a VT-1 examination of each bolted connection during the interval. The above described examinations and testing provide reasonable assurance of structural integrity and leak tightness of containment bolted connections.
Appendix J, ILRT and local leak rate testing shall be conducted as required by Plant licensing commitments to assure leak tightness of the containment. These activities have demonstrated their acceptability in assuring structural integrity and leak tightness and, thus, adequate torque or tension of containment bolted connections.
2
CONTAINMENT RELIEF REQUEST NO. 2 Implementation Schedule:
First inspection interval for IWE.
Status:
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(i) from performing the Code required examination since compliance with the proposed alternative will provide an adequate level of quality and safety. Prior NRC approval is required before implementing the proposed alternative.
3
CONTAINMENT RELIEF REQUEST NO. 3 System for Which Relief is Requested:
All Class MC Metallic Liners of Class CC Seals and Gaskets, Examination Category E-D, Item Numbers E5.10 and E5.20 of IWE-2500, Table IWE-2500-1, ASME Section XI, 1992 Edition, 1992 Addenda.
Code Requirement:
IWE-2500, Table IWE-2500-1, Category E-D, Item Numbers E5.10 and E5.20, requires seals and gaskets on airlocks, hatches, and other devices to be visually examined (VT-3) once each interval to assure containment leak-tight integrity.
Code Requirement From Which Relief is Requested:
In accordance with 1 OCFR50.55a(a)(3)(ii), relief is requested from performing the Code required visual examination (VT-3) on the above identified metal containment seals and gaskets since compliance with specified requirements would result in undue hardship or unusual difficulty without a compensating increase in the level of quality or safety.
Basis For Relief:
In accordance with Engineering Manual Procedure EM-09-10, "Palisades ILRT/LLRT Program," seals and gaskets receive a 10CFR50, Appendix J test. As noted in 1 OCFR50 Appendix J, the purpose is to measure leakage of containment or penetrations whose design incorporates resilient seals, gaskets or sealant compounds, and electrical penetrations fitted with seal assemblies.
Physical examination of seals and gaskets would require the joints, which are proven adequate through Appendix J testing to be disassembled. For electrical penetrations, this would involve a pre-maintenance Appendix J test, determination of cables at electrical penetrations, if enough cable slack is not available, disassembly of the joint, removal and examination of the seals and gaskets, reassembly of the joint, retermination of the cables, if necessary, post maintenance testing of the cables, and a post maintenance Appendix J test of the penetration. Additionally, removal of electrical penetration seals for examination would require replacement of the seals or the seals would be returned to the v~ndo_r for rea_ssembly.
1
CONTAINMENT RELIEF REQUEST NO. 3 The work required for the Containment Hatches would be similar except for the determination, retermination, and testing of cables. Not only does this require the use of outage staff hours, but imposes a risk that equipment could be damaged. The 1995 Edition of Section XI recognizes that disassembly of joints to perform these examinations is not warranted. Note 1 in Examination Category E-D was modified in the 1995 Edition of Section XI to state that "Sealed or gasketed connections need not be disassembled solely for performance of examinations." However, without disassembly, most of the surface of the seals and gaskets would be inaccessible.
Therefore, the examination would be meaningless.
Seals and gaskets are not part of the containment pressure boundary under current ASME Section Ill rules (NE-1220(b)). When the airlocks and hatches containing these materials are tested in accordance with 1 OCFR50 Appendix J, degradation of the seal or gasket material would be revealed by an increase in leakage rate. Corrective measures would be applied in accordance with Palisades Administrative Procedure 3.03, "Corrective Action Process," and the component retested. Repair or replacement of seals and gaskets is not subject to Code (1992 Edition, 1992 Addenda) rules (IWA-4111(b)(5));
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii), since compliance with specified requirements would result in undue hardship or unusual difficulty without a
- compensating increase in the level of quality or safety.
Alternate Examination:
As an alternative, seals and gaskets will be tested in accordance with 1 OCFR50 Appendix J as described in Engineering Manual Procedure EM-09-10, "Palisades ILRT/LLRT Program." Performance of Appendix J, Type B testing is performed at least once per refueling cycle or when the penetration is opened for maintenance or
- containment acce~s. This testing is conducted more frequently than the specified VT-3 examination. Also, Appendix J testing provides quantitative data indicating actual component performance verses the qualitative data provided by a VT-3 examination.
Seals and gaskets shall be examined, without disassembly of the joint, during the General Visual examination conducted once per inspection period.
The Palisades' Predetermined Periodic Activity Control-Program described in Administrative Procedure 5.19 directs the replacement of seals and gaskets at periodic intervals. These replacements shall continue to assure the subject seals and gaskets will not remain in service beyond their useful service life.
2
CONTAINMENT RELIEF REQUEST NO. 3 Nitrogen gas cylinders are used to maintain an inert gas blanket on the internal connections of the containment electrical penetrations. Each electrical penetration room has its own nitrogen blanket supply system that provides low pressure nitrogen to the internals of the penetration canisters. If a penetration seal developed a leak, usage of nitrogen would increase and be detected. Corrective actions would be taken in accordance with Palisades Administrative Procedure 3.03, "Corrective Action Process."
Implementation Schedule:
First inspection interval for IWE.
Status:
In accordance with 1 OCFR50.55a(a)(3)(ii), prior NRC approval is required when relief is requested from performing the above Code required examination since compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality or safety.
3
CONTAINMENT RELIEF REQUEST NO. 4 System for Which Relief is Requested:
Containment Inspection Program under the ASME Section XI Code Subsection IWL 1992 Edition with the 1992 Addenda.
Code Requirement:
Subparagraph IWL-2521 (b) requires "One tendon of each type (as defined in Table IWL-2521-1) shall be selected from the first year inspection sample and d_esignated as a common tendon. Each common tendon shall be examined during each inspection."
Code Requirement From Which Relief is Requested:
In accordance with 1 OCFR50.55a(a)(3)(i), relief is requested from performing the above required selection, since the proposed alternative will provide an acceptable level of safety and quality.
Basis For Relief:
Selection of common tendons after 25 years of tendon surveillance would not result in any increase in quality or safety.
The Palisades Tendon Surveillance Program is described in Engineering Manual Procedure EM-09-12, "Containment lnservice Inspection, Testing and Aging Management," and is based on the requirements of Plant Technical Specification 4.5 through amendment 183, dated June 10, 1998.
During the 1-year and 3-year surveillances, lift-off forces for the surveillance tendons were determined using the "change in sound" approach. This procedure involved
- tapping the shims with a hammer while increasing the tendon tension unt_il the ringing sound of any given shim was replaced by a dull thud, thus indicating that the struck shim was no longer in compression.
During the 3-year surveillance, a new approach.known as the "all shims loose" approach was evaluated and instituted during expanded scope testing. This procedure involved tapping the shims with a hammer while increasing tendon tension until all shims (ie, both halves of a single shim) were displaced by the hammer. Th~ "all shims loose" approach was adopted for all subsequent surveillances.
1
CONTAINMENT RELIEF REQUEST NO. 4 A correlation of the "change in sound" to the "all shims loose" approach was not performed, nor was it required, during the 3-year surveillance. At this point in plant life, it is not possible, nor is it prudent to perform such correlation. Palisades completed the 25-year surveillance during the summer and early fall of 1997. At most three additional surveillances will be performed during the remaining plant life. The value of selecting common tendons from the first year surveillance would not provide any useful data regarding the rate of prestress loss.
Alternate Examination:
The surveillance tendons shall be randomly but representatively selected from each group to meet the requirements of IWL and the Technical Specifications as reflected in the following table:
Tendon Required Minimum Required Maximum*
Category (Tech Spec 4.5.4bl (Table IWL-2521-1)
Dome (165) 4 5
Vertical (178) 4 5
Hoop (502) 5 5
For each inspection, the tendons shall be selected on a random basis except that those tendons whose routing has been modified to clear penetrations shall be excluded from the sample. This plan is presently described in Palisades Plant Technical Specification
. 4.5.
All Technical Specification 4.5 requirements shall apply to the tendons surveillance
-program. After ASME Section XI, Subsection IWL _is fully implemented, Palisades currently intends to submit a Technical Specification Change Request to delete Specification 4.5.
Implementation Schedule:
This was implemented during the first inspection interval for IWL which occurred during the 25-year tendon surveillance performed in 1997.
Status:
In accordance with 1 OCFR50.55a(a)(3)(i), relief is requested from performing the above Code required selection since the proposed alternative will provide an adequate level of quality and safety. NRC approval is required prior to implementing this relief request.
2
CONTAINMENT RELIEF REQUEST NO. 5 System for Which Relief is Requested:
All components subject to the rules and requirements for lnservice lnspeqtion of Class CC Concrete Components, Examination Category L-A, Concrete, Item L 1.11 as applicable to IWL-2310, Visual Examination and Personnel Qualification and IWA-2210, Visual Examinations.
Code Requirement:
ASME Section XI, 1992 Edition, 1992 Addenda, IWL-2310, Visual Examination and Personnel Qualification and IWA-2210, Visual Examinations require specific illumination and maximum direct examination distance for all concrete surfaces.
Code Requirement From Which Relief is Requested:
Relief is requested for Table IWA-2210-1, Visual Examination Requirements for minimum illumination and maximum direct examination distance of Class CC cpmponents under IWL-2310. Direct visual VT-3 examinations require a minimum illumination of 50fc, and a maximum examination distance of 4 feet.
Basis For Relief:
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii), since compliance with specified requirements would result in undue hardship or unusual difficulty without a compensating increase in the level of quality or safety.
10CFR50.55a was amended in the Federal Register (61FR41303) to require the use of the 1992 Edition, 1992 Addendum of Section XI when performing containment examinations. In addition to the requirements of.Subsection IWL, the rulemaking also imposes the requirements of Subsection IWA of the 1992 Edition, 1992 Addendum, of ASME Section XI for minimum illumination a*nd maximum direct distance of Class CC components, specifically for the examination of concrete under IWL-2510.
Accessibility to the higher portions of the containment liner plate makes it difficult to obtain the maximum direct examination distance and minimum illumination requirements. Meeting these requirements would require the installation of extensive temporary scaffold systems or a climbing scaffold system to access these portions of the containment. These scaffolds would provide limited access due to containment geometry restrictions, as well as, structural and equipment interferences. Many scaffold locations are located in higher radiation fields and worker dose would be increased.
Scaffold installation and removal would be required at extremely elevated locations 1
CONTAINMENT RELIEF REQUEST NO. 5
(>100 feet) and personnel safety risks would be significant: Relief is provided foL this case by 10 CFR 50.55a(b)(2)(x)(B).
Accessibility to the higher portions of the exterior containment reinforcing concrete makes it difficult to obtain the maximum direct examination distance requirements.
Meeting this requirement would require the installation of a portable man-basket system capable of rotating and elevating to access all portions of the containment exterior.
Installation of such a system requires the use of special equipment to lift the system to the containment dome. Once installed, the system requires monitoring by security, operations and maintenance personnel in order to prohibit unauthorized access to secure plant areas, to assure Plant power lines and other components are not affected during changing weather conditions and to maintain electrical and mechanical service to the system.
The NRC staff received seven comments which were consolidated into Public Comment# 2.3 in Part Ill of Attachment 6A to SECY-96-080. The Staff response to these comments is as follows, "Comments received from ASME members on the containment committees indicate that the newer, more stringent requirements of IWA-2210 were not.intended to be used for the examination of containments and were inadvertently included in Subsection IWL. The NRC agrees that remote examinations are the only practical methods for inspection of much of the containment surface area.
10CFR50.55a(b)(2)(x)(B) has been added to the final rule which contains alternative lighting and resolution requirements which may be used in lieu of those contained in IWA-2210-1." However, as specified within 10CFR50.55a(b)(2)(x)(B) of the final rule, this alternative applies to Subsection IWE, only.
Alternate Examination:
When performing remotely the visual examinations required by Subsection IWL, Section IWL-2510, the maximum direct examination distance may be extended and the minimum illumination may be decreased from those required in Table IWA-2210-1, provided that the conditions or indications for which visual examination is performed can be detected at the chosen distance and illumination.
2
CONTAINMENT RELIEF REQUEST NO. 5 Implementation Schedule:
First inspection interval for IWL.
Status:
In accordance with 1 OCFR50.55a(a)(3)(ii), relief is requested from performing the above Code required examination since compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality or safety.
3
CONTAINMENT RELIEF REQUEST NO. 6 System for Which Relief is Requested:
All Class MC components subject to the rules and requirements of IWE-5000.
examinations under ASME Section XI Code 1992 Edition with the 1992 Addenda.
Code Requirement:
ASME Section XI, 1992 Edition, Paragraph IWE-5240 titled "Visual Examination" states that the requirements of IWA-5246 (sic) for visual examination VT-2 are applicable following repair, replacement or modification.
Code Requirement From Which Relief is Requested:
Relief is requested from the requirement to perform VT-2 Visual Examination in connection with System Pressure Testing following Repair, Replacement or Modification under Article IWE-5000.
Basis For Relief:
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(i), since the proposed alternative will provide an adequate level of quality or safety; IWE-5210 states that except as noted within IWE-5240, the requirements of IWA-5000 are not applicable to Class MC or CC components. IWE-5240 states that the requirements of IWA-524[0] for visual examinations are applicable. IWA-5240 'identifies a "VT-2" Visual Examination. VT-2 examinations are conducted to detect evidence of leakage from pressure retaining components, with or without leakage collection
. systems, as required during the conduct of system pressure test.
Table IWE-2500-1, Examination Category E-P, identifies the examination method of 10 CFR 50, Appendix J and does not specifically identify a VT-2 Visual Examination.
1 O CFR 50, Appendix J provides requirements for testing; as well as, acceptable leakage criteria. These tests are performed by Appendix J test personnel and utilize calibrated equipment to determine acceptability. Additionally, Table IWE-2500-1 requires visual examinations of the containment each interval that would identify any structural degradation that may contribute to leakage. A "VT-2" Visual Examination will not provide additional assurance of safety beyond that of current Appendix J practices.
The presence of a VT-2 examiner in addition to Appendix J test personnel is inconsistent with ALARA good practices and duplicates effort without a compensating increase in safety or quality.
1
CONTAINMENT RELIEF REQUEST NO. 6 Alternate Examination:
Testing shall be conducted in accordance with 10 CFR 50, Appendix J, in lieu of IWE-5240.
Additionally, post maintenance or modification examinations required by Table IWE-2500-1 shall be performed prior to returning affected areas to service.
- implementation Schedule:
First inspection interval for IWE.
Status:
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(i) from performing the Code required examination since compliance with the proposed alternative will provide an adequate level 9f quality and safety. Prior NRC approval is required before implementing the proposed alternative.
2
- CONTAINMENT RELIEF REQUEST NO. 7 System for Which Relief is Requested:
All Class MC components subject to the rules and requirements of IWE-2420(b) and IWE-2420(c) examinations under ASME Section XI Code 1992 Edition with the 1992 Addenda.
Code Requirement:
ASME Section XI, 1992 Edition, Paragraph IWE-2420(b) requires that when a component examination results require evaluation of flaws, areas of degradation, or repairs in accordance with IWE-3000, and the component is found to be acceptable for continued service, the areas containing such flaws, degradation, or repairs shall be reexamined during the next inspection period listed in the schedule of the inspection program of IWE-2411 or IWE-2412, in accordance with Table IWE-2500-1, Examination Category E-C.
ASME Section XI, 1992 Edition, Paragraph IWE-2420(c) requires that when reexaminations required by IWE-2420(b) reveal that flaws, areas of degradation, or repairs remain essentially unchanged for three consecutive inspection periods, the areas containing such flaws, degradation, or repairs no longer require augmented examination in accordance with Table IWE-2500-1, Examination Category E-C.
Code Requirement Fro~ Which Relief is Requested:
Relief is requested from the requirement to perform successive examinations for repairs as required by IWE-2420(b) and IWE-2420(c).
Basis For Relief:
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(ii), since compliance with specified requirements would result in undue hardship or unusual difficulty without a compensating increase in the level of quality or safety.
1
CONTAINMENT RELIEF REQUEST NO. 7 The purpose of a repair is to restore the component to an acceptable condition for continued service in accordance with the acceptance standards of IWE-3000.
IWA-4150 requires the owner to conduct an evaluation of the suitability of the repair including consideration of the cause of failure. If the repair has restored the component to an acceptable condition, successive examinations are not warranted. If the repair was not suitable, then the repair does not meet Code requirements and the component is not acceptable for continued service. Neither IWB-2420(b), IWC-2420(b), nor IWD-2420(b) requires a repair to be subjected to successive examination requirements.
Furthermore, if the repair area is subject to accelerated degradation, it would still require augmented examination in accordance with Table IWE-2500-1, Examination Category E-C.
In their resolution to public comment# 3.3, the NRC stated, "The purpose of IWE-2420(b) is to manage components found to be acceptable for continued service (meaning no repair or replacement at this time) as an Examination Category E-C component... If the component had been repaired or replaced, then the more frequent examination would not be needed."
The requirement to perform successive examinations following repairs has been removed in the 1997 Addenda of ASME Section XI. This addenda was published on December 31, 1997.
Alternate Examination:
Examination of repairs shall be performed in accordance with the requirements of IWA-4150, "Verification of Acceptability."
Implementation Schedule:
First inspection interval for l\\IVE.
Status:
In accordance with 10 CFR 50.55a(a)(3)(ii), prior NRC approval is required when relief is requested from performing the above Code required examination since compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality or safety.
2