ML20211H862
| ML20211H862 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/23/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20211H860 | List: |
| References | |
| NUDOCS 9909020195 | |
| Download: ML20211H862 (14) | |
Text
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UNITED STATES g
j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 3066H001 r
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RELIEF FROM CERTAIN INSERVICE INSPECTION REQUIREMEJI!!
1 TO FACILITY OPERATING LICENSE NOS. NPF-10 AND NPF-15 SOUTHERN CAllF_ORNIA EDISON COMPANY SAN DIEGO GAS AND ELECTRIC COMPANY THE CITY OF RIVERSIDE. CALIFORNIA l
THE CITY OF ANAHEIM. CAllFORNIA SAN ONOFRE NUCLEAR GENERATING STATION. UNITS 2 AND 3 DOCKET NOS. 50-361 AND 50-362
1.0 INTRODUCTION
The Technical Specifications (TSs) for the San Onofre Nuclear Generating Station (SONGS),
Units 2 and 3, state that the inservice inspection (ISI) of the American Society of Mechanical Engineers (ASME) Code Class 1,2, and 3 components shall be performed in accordance with Section XI of the ASME Soller and Pressure Vessel Code (ASME Code) and applicable addenda as required by 10 CFR 50.55a(g). In the FederalRegister dated August 8,1996, the NRC amended its regulations to incorporate by reference the 1992 Edition with the 1992 Addenda of Subsection IWE and Subsection lWL of Section XI of the ASME Code.
Subsections IWE and IWL provide the requirements for ISI of Class CC (concrete containments), and Class MC (metal!ic containments) of light-water cooled power plants. The effective date for the amended rule was September 9,1996, and it requires licensees to incorporate the new requirements into their ISI plans and to complete the first containment inspection by September 9,2001. However, a licensee may propose alternatives to or submit a request for relief from the requirements of the regulation pursuant to 10 CFR 50.55a(a)(3) and (g)(5).
The regulations at 10 CFR 50.55a(a)(3) state that alternatives to the requirements of paragraph (g) may be used, when authorized by the NRC, if (i) the proposed alternatives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
l By letter dated June 25,1999, the licensee submitted to the NRC Relief Request (RR) Nos.
RR-E-2-03 through RR-E-2-08, from the examination requirements of the applicable ASME Code,Section XI, for the first ISI interval.
ENCLOSURE h
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- l 2.0 EVALUATION OF RELIEF REQUESTS i
l 2.1 Relief Reauest No. RR E-2-03 l
2.1.1 System / component (s) for Which Relief is Requested Seals and gaskets of Class MC pressure retaining components, Examination Category E-D, item Numbers E5.10 and E5.20 of IWE-2500, Examination and Pressure Test Requirements,"
Table IWE-2500-1, ASME Section XI,1992 Edition,1992 Addenda, i
2.1.2 Code Requirement (s) i
!WE-2500, Table IWE-2500-1, 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.
2.1.3 Code Requirement from Which Relief is Requested (as stated)
Relief is requested from performing the Code-required visual examination, VT-3, on the above identified metallic liner of containment seals and gaskets.
2.1.4 Basis for Relief (as stated)-
10 CFR 50.55a was amended, as cited in the Federa/ Register (61 FR 41303), to l
require the use of the 1992 Edition,1992 Addenda, of Section XI when performing containment examinations. The penetrations discussed below contain seals and gaskets:
Electrical Penetrations Electrical penetrations use a header plate attached to a containment penetration nozzle flange with redundant 0-rings between the header plate and flange face.
Modules through which electrical conductors pass are installed in the header plate. The two electrical penetration assembly configurations used for all electrical conductors passing through the shell wall are the canister-type and the modular (pancake) type assemblies. The canister type assemblies are used for the medium voltage power circuits,6900 volts. The modular-type assemblies are used for the low-voltage power circuits,600 volts and below.
The penetration canistm's a hollow cylinder bolted at one end to the steel penetration sleeve flange and closed at both ends with sealed header plate assemblies. The canister is provided with a test plug on the outside of the containment to allow test pressurization of the penetration assembly. The modular-type assemblies consist of a header plate in which a group of small, interchangeable, modular penetrations are fitted. The header plate mates with the flange welded to the nozzle, which is bolted to the penetration sleeve flange.
Double silicone O-rings provide a monitorable seal between the header plate and the flange. The header plate is provided with a monitoring hole on the outside of the containment to allow test pressurization of the penetration assembly. The
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method of sealing the electrical penetration assemblies depends upon the type of cable and connector assembly involved. In general, three types are used:
Type 1 -
Medium voltage power,6900 volts (canister-type assembly) i e
Type 2 -
Low-voltage power and control,600 volts and below (modular-type assembly)
Type 3 -
Instrumentation, thermocouple leads, coaxial and other special wires (modular-type assembly)
Type 1 penetrations consist of insulated conductors that are passed through the header plates and are potted to effect a pressure seal. Mechanical splices within the potting compound provides gas stops. High-voltage insulating bushings and seals also are used to provide the barrier.
Type 2 and 3 penetrations have conductors that are passed through the modules and are potted to effect a pressure seal. Epoxy-encapsulated splices within the potting compound provides gas stops. The module is fitted into the header plate with the O-rings in each pressure barrier acting to make the necessary pressure seal.
Each penetration is pressurized with dry nitrogen to maintain and monitor integrity and to prevent the intrusion of moisture into the penetration.
These seals and gaskets cannot be inspected without disassembly of the penetration to gain access to the seats and gaskets.
Containment Personnel and Emeraency Escape Airlocks. and Eauioment Hatch The Personnel and Emergency Escape Airlocks utilize an inner and outer d(ci with gasket surfaces to ensure leak tight integrity. These airlocks also contain other gaskets and seals such as the handwheel shaft seals, electrical penetrations, blank flanges, and equalizing pressure connections, which require disassembly to gain access to the gaskets and seals. The Equipment Hatch utilizes a double gasket door to ensure leak tight integrity.
Seals and gaskets receive a 10 CFR 50 Appendix J, Type B test. As noted in 10 CFR 50 Appendix J, the purpose of Type B tests is to measure leakage of containment or penetrations whose design incorporates resilient seals, gaskets, sealant compounds, and electrical penetrations fitted with flexible metal seal assemblies. Examination of seals and gaskets require the joints, which are proven adequate through Appendix J testing, be disassembled. For electrical penetrations, this would involve a pre-maintenance Appendix J test, disconnection 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, re-termination of the cables if necessary, post
1 maintenance testing of the cables, and a post maintenance Appendix J test of the penetration.
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The work required for the Containment airlocks and hatch would be similar l
except for the disconnection, re-termination, and testing of cables. This imposes l
the risk that equipment could be damaged. The 1992 Edition,1993 Addenda, of ASME Section XI recognizes that disassembly of joints to perform these examinations is not warranted. Note 1 in Examination Category E-D was i
modified in the 1995 Edition of ASME Section XI to state that sealed or gasket i
connections need not be disassembled solely for performance of examinations.
i However, without disassembly, most of the surface of the seals and gaskets would be inaccessible.
For those penetrations that are routinely disassembled, a Type B test is required upon final assembly and prior to start-up. Since the Type B test will assure the leak tight integrity of primary containment, the performance of the visual examination would not result an increase in the level of safety or quality.
When the airlocks and hatch containing seals and gaskets are tested in accordance with 10 CFR 50, Appendix J, degradation of the seal or gasket material would be revealed by an increase in the leakage rate. Corrective measures would be applied and the component retested. Repair or replacement of seals and gaskets is not subject to Code (1992 Edition,1992 Addenda) rules in accordance with Paragraph IWA 4111(b)(5) of ASME Section XI.
The Equipment Hatch is opened during outages when necessary. Prior to final closure, the hatch gaskets and sealing surfaces are inspected for damage, cracks, cuts, or cleanliness that may affect sealing integrity. The airlock door gaskets are also inspected and cleaned prior to final closure after containment entries are performed. Prior to establishing containment integrity, the airlocks and hatch are tested to confirm their sealing capability.
IWE-2500-1 is a burden without any compensating increase in the level of safety or quality.
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(ii). Compliance with l
the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
i Testing the seals and gaskets in accordance with 10 CFR 50, Appendix J will provide adequate assurance of the leak-tight integrity of the seals and gaskets.
The requirement to examine seals and gaskets has been removed in the rewrite of Subsection IWE of ASME Section XI. This rewrite has been approved by the ASME and published in July 1998.
2.1.5 Alternative Examination (as stated)
The leak-tightness of seats and gaskets will be tested in accordance with 10 CFR 50, Appendix J.
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2.1.6 Evaluation of RR-E-2-03 The staff position is that penetration seals and gaskets are part of the ccatainment pressure boundary. The staff has determined that the licensee's alternative examination of the containment penetration seals and gaskets (including those of electrical penetrations) would verify their leak-tight integrity during the Type B testing as required by 10 CFR Part 50, Appendix J.
The equipment hatch is removed during outages, when necessary. The licensee states that prior to final closure, the hatch gaskets and door sealing face are inspected for damage that could prevent sealing. The airlock door gaskets are inspected for damage and cleaned to l
ensure their integrity and sealing capability.
The staff has determined that these actions are adequate to ensure the integrity of the SONGS containment penetration seals and gaskets. Therefore, the staff finds the licensee's alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i) because the proposed alternative provides an acceptable level of quality and safety.
l 2.2 Relief Reauest No. RR-E-2-04 2.2.1 System / component (s) for Which Relief is Requested All Class MC, Subarticle IWE-2200(g), preservice examination requirements of reapplied painted or coated containment.
2.2.2 Code Requirement (s)
ASME Section XI,1992 Edition,1992 Addenda, Subsection IWE-2200(g) requires that when paint or coatings are reapplied the condition of the new paint ur coating shall be documented in the preservice examination records.
2.2.3 Code Requirement from Which Relief is Requested (as stated)
Relief is requested from the requirement to perform a preservice inspection of new paint or coatings.
2.2.4 Basis for Relief (as stated)
Paint and coatings are not part of the containment pressure boundary under current Code rules as they do not provide the pressure retaining functions of components (Paragraph NE-2110 (b)(5) of ASME Section lil). The paint and matings on the containment pressure boundary were not subject to Code rules when they were originally applied and are not subject to ASME Section XI rules for repair or replacement in accordance with IWA-4111(b)(5). Inside containment coatings are controlled by procedure (SO23-I-1.11.1) at San Onofre. The coating procedure covers the removal, preparation, application and inspection of qualified coatings for use inside the containment and is performed in accordance with an NRC approved quality assurance program.
Specific requirements include:
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Coating materials are pre qualified to Design Basis Accident environmental conditions according to ANSI N101.2 and the applicable portions of ANSI N5.12.
2.
A coating application procedure was developed based on the manufacturer's recommendation for application of the selected coating system.
3.
Quality Assurance requirements are enforced for the coating materials and the application procedure.
4.
Personnel performing preparation and application are qualified by the successful completion of a qualification guide on coatings inside the containment (Ref. ANSI N101.4).
5.
Quality Control personnel perform inspections to verify conformance to the coating application procedure.
6.
Documentation demonstrating conformance to the coating procedure is maintained.
Recording the condition of reapplied coating in the preservice record does not substantiate the containment structuralintegrity. Should deterioration of the coating in the reapplied area occur, the area will require additional evaluation regardless of the preservice record. Recording the condition of new paint or coating in the preservice records does not increase the level of quality and safety of the containmant.
In SECY 96-080," Issuance of Final Amendment to 10 CFR Section 50.55a to incorporate by Reference the ASME Boiler and Pressure Vessel Code (ASME Code),Section XI, Division 1, Subsection IWE and Subsection IWL," dated April 17,1996, response to Comment 3.2 about IWE 2200(g) states, "In the NRC's opinion, this does not mean that a' visual examination must be performed with every application of paint or coating. A visual examination of the topcoat to determine the soundness and the condition of the topcoat should be sufficient."
This is currently accomplished through the coating inspections performed after reapplication per the San Onofre Nuclear Generating Station (SONGS) coating procedure for inside containment. Also, the condition of the coatings is examined periodically in accordance with 10 CFR 50.65, " Requirements for
. Monitoring Effectiveness of Maintenance at Nuclear Power Plants," and during the general visual examination required by IWE. These periodic examinations will identify evidence of flaking, blistering, peeling, discoloration, or other signs of coating distress which might be indicative of degradation of the containment structuralintegrity.
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(1). The San Onofre Nuclear Generating Station (SONGS) coating program for inside containment currently provides an adequate level of quality and safety.
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7-The requirement to perform a preservice examination when paint or coatings are reapplied has been removed in the rewrite of Subsection IWE of ASME Section XI. This rewrite has been approved and published by ASME in July 1998.
2.2.5 Alternate Examinations (as stated)
Reapplied paint and coatings on the containment vessel will be examined in accordance with the SONGS coating program for inside containment. Although repairs to paint or coatings are not subject to the repair / replacement rules of ASME XI (Inquiry 97-22), repairs to the primary containment boundary, if required, would be conducted in accordance with ASME Section XI Code rules.
1 2.2.6 Evaluation The licensee indicates that the containment coating material, its application, and inspection are in accordance with the NRC-approved quality assurance (QA) program and applicable ANSI standards. The staff considers the alternative program, as stated by the licensee, for application of paint or coating, its inspection, and its QA provisions acceptable for protecting the inside steel surfaces of the SONGS containment. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i) as the alternative would provide an acceptable level of quality and safety.
2.3 Relief Reauest No. RR-E-2-05 2.3.1 System / component (s) for Which Relief is Requested All Class MC, Subarticle IWE-2500(b) visual examinations per Table IWE-2500-1 of painted or coated containment components prior to removal of paint or coatings.
2.3.2 Code Requirement (s)
ASME Section XI,1992 Edition,1992 Addenda, Subarticle IWE-2500(b) requires that when paint or coatings are to be removed, the paint or coatings shall be visually examined in accordance with Table IWE-2500-1 prior to removal.
2.3.3 Code Requirement from Which Relief is Requested (as stated)
Subarticle IWE-2500(b) requires that when paint or coatings are to be removed, the paint or coatings shall be visually examined in accordance with Table IWE-2500-1 prior to removal.
2.3.4 Basis for Relief (as stated) 10 CFR 50.55a was amended, as cited in the Federa/ Register (61 FR 41303), to require the use of the 1992 Edition,1992 Addenda, of ASME Section XI when performing containment examinations. Paint and coatings are no.t part of the containment pressure boundary under current Code rules as they do not provide the pressure retaining functions of components (Paragraph NE-2110 (b)(5) of ASME Section Ill). The interiors of containment are painted to prevent corrosion.
.eu.sem, e--en om
r Neither paint nor coatings contribute to the structural integrity or leak tightness of g
the containment. Furthermore, the paint and coatings on the containment
_ pressure boundary were not subject to Code rules when they were originally applied and are not subject to ASME Section XI rules for repair or replacement in accordance with IWA-4111(b)(5). Degradation or discoloration of the paint or coating materials on containment would be an indicator of potential degradation of the containment pressure boundary. Additional measures would have to be employed to determine the nature and extent of any degradation, if present. The application of ASME Section XI rules for removal of paint or coatings when unrelated to an ASME Section XI repair or replacement activity is a burden without a compensating increase in quality or safety.
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Relief is requested in accordance with 10 CFR 50.55a(a)(3)(l). The SONGS coating program for inside containment currently provides an adequate level of quality and safety.
The requirement to inspect coatings prior to removal has been removed in the rewrite of Subsection IWE of ASME Section XI. This rewrite has been approved and published by ASME in July 1998.
2.3.5 Alternate Examinations (as stated)
The condition of the containment vessel base material will be verified prior to the application of new paint or coating as required by the SONGS coating procedure for inside containment, if degradation is identified, additional measures will be applied to determine if the containment pressure boundary is affected. Repairs to the primary containment boundary, if required, will be conducted in accordance with ASME Section XI Code rules.
L 2.3.6 Evaluation As indicated in the staff evaluation of RR-E 2-04, the staff finds that the SONGS coating procedure is adequate to monitor the proper removal of the old paint and application of the new coatings. Performing additional examination prior to removal of the old paint and documenting its condition, in addition to requirements of the licensee's QA program, would result in a hardship without a compensating increase in the level of quality or safety. Therefore, the staff concludes that the licensee's alternative coating program is authorized pursuant to 10 CFR 50.55a(a)(3)(ii).
2.4 Relief Reouest No. RR-E-2-06 2.4.1 System / component (s) for Which Relief is Requested All Class MC, paragraphs IWE-2420(b) and IWE-2420(c) successive examination requirements for components found acceptable for continued service.
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2.4.2 Code Requirement (s)
Paragraphs IWE-2420(b) and IWE-2420(c) of the 1992 Edition,1992 Addenda of ASME Section XI, requires that when component examination results require evaluation of flaws, evaluation of areas of degradation, or repairs in accordance with Article IWE-3000,
" Acceptance Standards," 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 paragraph IWE-2411,
" Inspection Program A," or paragraph IWE-2412 " Inspection Program 8,"in accordance with Table IWE-2500-1, Examination. Category E-C.
2.4.3 Code Requirement from Which Relief is Requested (as stated)
Relief is requested from the requirement of Paragraphs IWE-2420(b) and IWE-2420(c) to perform successive examination of repairs.
2.4.4 Basis for Relief (as stated) 10 CFR 50.55a was amended, as cited in the Federal Register (61 FR 41303), to require the use of the 1992 Edition,1992 Addenda, of Section XI, when performing containment examinations. The purpose of a repair is to restore the component to an acceptable condition for continued service in accordance with the acceptance standards of Article IWE-3000. Paragraph IWA-4150,
" Verification of Acceptability," 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 Paragraph IWB-2420(b), Paragraph IWC-2420(b),
nor Paragraph IWD-2420(b) requires a repair to be subject 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.
The successive examination of repairs in accordance with Paragraphs IWE-2420(b) and IWE-2420(c) constitutes a burden without a compensating increase in quality or safety.
In SECY 96-080," Issuance of Final Amendment to 10 CFR Section 50.55a to incorporate by Reference the ASME Boiler and Pressure Vessel Code (ASME Code),Section XI, Division 1, Subsection IWE and Subsection IWL," dated April 17,1996, response to comment # 3.3 states "[T]he 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."
L Relief is requested in accordance with 10 CFR 50.55a(a)(3)(ii). Compliance with the specified requirements of this section would result in hardship or unusual l
difficulty without a compensating increase in the level of quality and safety.
The requirement to perform successive examinations following repairs has been 1
removed in the rewrite of Subsection IWE of ASME Section XI. This rewrite has been approved and published by the ASME in July 1998.
2.4.5 Alternate Examinations (as stated)
Successive examinations in accordance with Paragraphs IWE-2420(b) and IWE 2420(c) are not required for repairs made in accordance with Article am-4000, 2.4.6 Evaluation Paragraph IWE-2420(b) requires that when examinations result in performance of a repair / replacement activity, the items subjected to repair / replacement shall be reexamined during the next inspection period. However, the licensee is proposing that repairs / replacements of Class MC components will be performed in accordance with the requirements of paragraph IWA-4000 of the Code, the intent of which is to use the construction code to restore the component to its original condition, and the component will then be inspected on a normal inspection interval rather than reexamined during the next period.
Repair / replacement activities are followed by an examination to determine the suitability of the repair / replacement. Under the licensee's proposal, when the post-repair / replacement examination indicates the repair / replacement is acceptable, the component will have been restored to compliance with the Code. When, however, the post-repair / replacement examination indicates the repair / replacement is not suitable, then the repair does not meet Code requirements and the component is not acceptable for continued service; further i
restoration work would be required. Once a component is restored to Code compliance, successive examinations are not warranted and it is acceptable to return the component to a normalinspection interval. This approach is consistent with the successive examination l
requirements of Class 1,2, and 3 components per paragraphs IWB 2420(b), IWC-2420 (b), or lWD-2420 (b), and provides reasonable assurance of component integrity.
Since the proposed alternative will return components to Code compliance, the NRC staff finds that a successive examination performed in the next period is not warranted after repair or replacement of a component, and that imposition of the Code requirement of ASME Code Section X1,1992 Edition, Subsection IWE, Class MC, paragraph IWE-2420 (b) and (c) would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii).
2.5 Relief Reauest No. RR-E-2-07 2.5.1 Systems / components for Which Relief is Requested 1-Class MC pressure retaining botting.
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2.5.2 Code Requirement (s) i ASME Section XI,1992 Edition with the 1992 Addenda, Table IWE-2500-1 Examination Category E-G, Pressure Retaining Bolting, item 8.20.
2.5.3 Code Requirement from Which Relief is Requested (as stated)
Reliefis requested from ASME Section XI 1992 Edition,1992 Addenda, Table IWE-2500-1 Examination Category E-G, Pressure Retaining Bolting, item 8.20. Table IWE-2500-1 requires a bolt torque or tension test on bolted connections that have not been disassembled and reassembled during the inspection interval.
2.5.4 Basis For Relief (as stated) 10 CFR 50.55a was amended, as cited in the Federa/ Register (61 FR 41303), to j
require the use of the 1992 Edition,1992 Addenda, of ASME Section XI when 1
performing containment examinations. 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 would require that the bolting be loosened and then re-torqued or re-tensioned.
Each containment penetration receives a 10 CFR 50 Appendix J, Type B test in accordance with the specified testing frequencies. As noted in 10 CFR 50 Appendix J, the purpose of Type B tests is to measure leakage of containment penetrations whose design incorporates resilient seals, gaskets, sealant compounds, and electrical penetrations fitted with flexible metal seal assemblies.
The performance of the Type B test itself 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 for any other ASME Section XI, Class 1, 2, or 3 bolted connections or their supports as part of the inservice inspection program.
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(ii). Examination of bolt torque or tension requires the joints be disassembled. For electrical penetrations, this would involve a pre-maintenance Appendix J test, disconnection of cables at electrical penetrations if enough cable slack is not available, disassembly of the joint, removal and exarnination of the seals and gaskets, reassembly of the joint, re-termination of the cables if necessary, post maintenance testing of the cables, and a post maintenance Appendix J test of the penetration. Relieving bolt torque and subsequent re-torquing of bolted connections which are verified not to experience unacceptable leakage through 10 CFR 50, Appendix J Type B testing results in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
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The requirement to perform bolt torque or tension tests has been removed in the rewrite of Subsection iWE of ASME Section XI. This rewrite has been approved and published by the ASME in July 1998.
2.5.5 Alternate Examination (s)(as stated)
The following examinations and tests required by Subsection IWE ensure the structural Integrity and the leak-tightness of Class MC pressure retaining botting, and, therefore, no additional alternative examinations are proposed:
(1)
Exposed surfaces of bolted connections shall be visually examined in accordance with requirements of Table IWE 2500-1,
~ Examination Category E-G, Pressure Retaining Bolting, item No.
E8.10, and (2)
Bolted connections shall meet the pressure test requirements of Table IWE-2500-1, Examination Category E-P, All Pressure Retalning Components, item E9.40.
2.5.6 Evaluation The requirement to perform bolt torque or tension tests has been removed in the rewrite of Subsection IWE of ASME Section XI. This rewrite has been approved and published by the ASME in July 1998. The staff concludes that the torque or tension testing of bolts during IWE examination, when the bolts are not disassembled, will result in hardship without a j
compensating increase in the level of safety and quality. Therefore, the staff finds that the alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii).
2.6 Relief Reauest No. RR-E-2-ja 2.6.1 System / Component (s) for Which Relief is Requested All components subject to the requirements for ISI 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.
2.6.2 Code Requirements ASME Section XI,1992 Edition,1992 Addenda, IWL-2310, Visual Examination and Personnel Qualification and IWA-2210, Visual Examinations requires specific minimum illumination and maximum direct examination distance for all concrete surfaces.
2.6.3 Code Requirements from Which Relief is Requested (as stated)
Relief is requested for Paragraph IWA-2210, Visual Examination Requirements for minimum illumination and maximum direct examination distance of Class CC components under Paragraph IWL-2310.
I e.
2.6.4 Basis for Re' lief (as stated) 10 CFR 50.55a was amended in the Federal Register (61FR41303) to require the use of the 1992 Edition,1992 Addenda, of Section XI when performing containment examinations. In addition to the requirements of Subsection IWL, the rule also imposes the requirements of Subsection IWA of the 1992 Edition, 1992 Addendum, of ASME Section XI for minimum illumination and maximum direct examination distance of Class CC components, specifically for the examination of concrete under Paragraph IWL-2510.
Accessibility to higher portions of the containment structure makes it a hardship to obtain the maximum direct examination distance and minimum illumination requirements. The installation of extensive temporary scaffold systems or a climbing scaffold system to access these portions of the containment would be necessary. These scaffolds would provide limited access due to containment geometry restrictions as well as structural and equipment interferences. The installation and removal of these scaffolds would increase both risk to personnel safety and safety related systems in order to meet Paragraph IWA-2210 requirements.
The NRC staff received seven comments that were consolidated into Public Comment # 2.3 in Part lli of Attachment 6A to SECY-96-080. The Staff response to these concerns 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 containment and were inadvertently included in Subsection IWL. The NRC agrees that remote examinations are the only practical method for inspecting much of the containment surface area. 9 50.55a(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 the requirements contained in IWA-2210-1."
However, as specified within @ 50.55a(b)(2)(x)(B) of the final rule, this alternative applies only to Subsection IWE.
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(ii). Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
The requirement to comply with IWA-2210 has been removed in the rewrite of Subsection iWE of ASME Section XI. This rewrite has been approved and published by ASME in July 1998.
2.6.5 Alternative Examinations (as stated)
When the visual examinations required by Subsection IWL, Paragraph IWL-2510, are performed remotely, the maximum direct examination distance specified in Table IWA-2210-1 may be extended, and the minimum illumination requirements specified in Table IWA-2210-1 may be decreased. The remote visual examinations will be demonstrated at the chosen distance and illumination
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\\ 4 to be capable of detecting the conditions or indications for which the visual examination is performed.
2.6.6 Evaluation As described in " Basis for Relief" section above, because the accessibility to higher portions of the containment structure will make it a hardship to obtain the maximum direct examination distance and minimum illumination requirements, the licencee proposed an alternative to the requirements for the measurement of illumination and examination distance for visual examinations specified in ASME Section XI,1992 Edition,1992 Addenda, lWL-2310," Visual Examination and Personnel Qualification," and IWA-2210," Visual Examination." The attemate examinations state that the code-required maximum direct examination distance may be
- .,v.ooood ood the minimum lliumination may be decreased provided that the conditions or indications for which the visual examination is performed can be detected at the chosen distance and illumination.
The visual examinations on containment are performed to determine if damage or degradation, including cracks, wear, corrosion, erosion, or other physical damage, warrant additional evaluation or repair of the structure, in order for the visual examinations to be performed in such a way as to detect critical flaws, proper lighting is essential. lWA-2210 allows for remote examination as long as the remote examination procedure is demonstrated to resolve the elected test chart characters, in addition, the licensee noted the staff's response to pubite i
comments on SECY-96-080 that the NRC agrees that remote examinations are the only practical method for inspecting much of the containment surface area.
On the basis discussed above, the staff finds that the alternative examinations proposed by the licensee are authorized pursuant to 10 CFR 50.55a(a)(3)(ii) on the basis that compliance with Code requirements would result in a hardship without a compensating increase in the level of Quality and safety.
3.0 CONCLUSION
On the basis of its review, the staff concludes that the proposed alternatives in RR-E-2-03 and RR-E 2-04 provide an acceptable level of quality and safety and are therefore authorized pursuant to 10 CFR 50.55a(a)(3)(i). Further, the staff concludes that for RR-E-2-05,
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RR-E-2-06, RR-E-2-07 and RR-E 2-08, compliance with the specified requirements of the Code would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Therefore, the proposed attematives in RR E-2-03 through RR-E-2-08 are authorized pursuant to 10 CFR 50.55a(a)(3)(ii).
i Principal Contributor: L. Raghavan Date: August 23,1999