ML20236K398
| ML20236K398 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 06/30/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20236K364 | List: |
| References | |
| NUDOCS 9807090306 | |
| Download: ML20236K398 (22) | |
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1 UNITED STATES
! 8) E NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20seH001 l
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF RELIEF REQUESTS FROM SOME OF THE ASME SECTION XI RE0VIREMENTS )
AS ENDORSED BY 10 CFR 50.55a FOR CONTAINMENT INSPECTION TOLEDO EDISON COMPANY CENTERIOR SERVICE COMPANY bND l THE CLEVELAND ELECTRIC ILLUMINATING COMPANY j DAVIS-BESSE NUCLEAR POWER STATION. UNIT NO. 1 l
DOCKET NO. 50-346
1.0 INTRODUCTION
The Technical Specifications for the Davis-Besse Nuclear Power Station 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 Boller and Pressure Vesse7 Code and applicable addenda as required by 10 CFR 50.55a(g), except where specific written relief has been granted by the Commission.
Section 50.55a(a)(3) states 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.
Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, " Rules for Inservice Inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the first 10-year interval and subsecuent intervals comply with the requirements in the latest edition and addenca of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b), 12 months prior to l
ENCLOSURE 1 9807090306 90063036 DR ADOCK 050
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-the start.of the 120-month interval, subject to the limitations and modifications listed therein. The applicable ASME Code,Section XI, for the Davis-Besse Nuclear Power Station second 10-year (ISI) interval is the 1986 edition. The components (including supports) may meet the requirements set forth in subsequent editions and addenda of the ASME Code incorporated by reference in 10 CFR 50.55a(b) subject to the limitations and modifications listed therein and subject to Comission approval.
Pursuant to.10 CFR 50.55a(g)(5), if the licensees determine that conformance with an examination requirement of Section XI of the ASME Code is not practical for its facility, information shall be submitted to the Comission in support of that determination and a request made for relief from the ASME Code requirement. After evaluation of the determination, pursuant to
.10 CFR 50.55a(g)(6)(1), the Comission may grant relief and may impose !
alternative requirements that are determined to be ' authorized by law, will not endanger life, property, or the comon defense and security, and are otherwise i in the public interest, giving due consideration to the burden upon the licensees that could result if the requirements were imposed.
By letter dated December 22, 1997, as supplemented April 7, 1998, the Toledo Edison Company, Centerior Service Company, ard The Cleveland Electric Illuminating Company, the licensees for the Davis-Besse Nuclear Power Station, submitted to the NRC requests for relief from the examination requirement of 1 the applicable ASME Code,Section XI, for the second ISI interval examinations. The NRC staff has reviewed and evaluated Relief Request Nos.
RR-El through RR-E10 for the second 10-year ISI interval at Davis-Besse.
2.0. BACKGROUND l In the federal Register dated August 8,1996 (61 FR 41303), the Nuclear Regulatory Comission (NRC) announced an amendment to 10 CFR 50.55a(b)(2)(vi),
" Effective edition and addenda of Subsection IWE and Subsection IWL,Section XI" (rule). The' rule incorporated by reference the 1992 edition with 1992 addenda of Subsections IWE and IWL of Section XI of the ASME Boiler and Pressure Vessel Code (Code). Subsections IWE and IWL provide the requirements for inservice inspection (ISI) of Class CC (concrete containments), and Class MC (metallic containments) of light-water cooled power plants. The effective date for the amended rule was September 9, 1996.
The rule requires the licensees to incorporate the new requirements into their ISI plans and to complete the first containment inspection by September 9, 2001. However, a licensee can submit a request for relief from one or more requirements of the regulation (or the endorsed code requirements) with proper justification. The provision for granting relief is incorporated in the regulation.
The Davis-Besse containment vessel was constructed in accordance with ASME Section III, Subsection B for nuclear vessels, 1968 Edition including the
, Summer 1969 Addenda. The rules of Subsection IWL do not apply to the Davis-Besse containment vessel.
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i 3.0 RELIEF RE0 VEST NO. RR-El 3.1 SYSTEM / COMPONENT (S) FOR WHICH RELIEF IS RE0 VESTED 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.
l 3.2 CODE REQUIREMENT (S)
IWE-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. ,
3.3 CODE REQUIREMENT FROM WHICH RELIEF IS RE0 VESTED (as stated)
Relief is requested from performing the Code-required visual examination, VT-3, on the above identified metal containment seals and gaskets.
3.4 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 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. One type, manufactured by Amphenol uses seals and gaskets to assure leak tight integrity. A second type, manufactured by Conax uses a set of compression fittings.. Replacement i modules for the Amphenol penetrations use a combination of 0-rings and l compression fittings. Each penetration is pressurized with dry nitrogen to maintain and monitor integrity and to prevent the intrusion of~
moisture into the penetration. l These seals and gaskets cannot be inspected without disassembly of the penetration to gain access to the seals and gaskets.
Containment Personnel. Eauioment. and Emeroency Escape Hatches The Personnel, Equipment, and Emergency Escape Hatches utilize an inner and outer door with gasket surfaces to ensure a leak tight integrity.
These hatches 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.
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l l Seals and gaskets receive a 10 CFR 50 Appendix J, Type B test. As noted in i
10 CFR 50 Appendix J, the purpose of Type B tests is to measure leakage of containment or penetrations whose design incorporates resilient seals, l gaskets, sealant compounds, and electrical penetrations fitted with flexible l
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, determination of cables at electrical penetrations if enough cable slack is
- not available, disassembly of the joint, removal and examination of the seals l and gaskets, reassembly of the joint, re-termination of the cables if l
necessary, post maintenance testing of the cables, and a post maintenance Appendix J test of the penetration. The work required for the Containment l Hatches would be similar except for the determination, re-termination, and testing of cables. This imposes 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 modified in the 1995 Edition of ASME Section XI to state that sealed or gasket 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.
! 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 i of the visual examination would not increase in the level of safety or quality.
Seals and gaskets are not part of the containment pressure boundary under l current Code rules (NE-1220 (b)). When the airlocks and hatches containing these materials are tested in accordance with 10 CFR 50, Appendix J, degradation of the seal or gasket material would be revealed by an increase in
- l. 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) l of ASME Section XI.
[ The visual examination of seals and gaskets in accordance with IWE-2500, Table
! IWE-2500-1 is a burden without any compensating increase in the level of L
safety or quality.
l 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 difficulty without a compensating increase in the level of quality and safety. 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 ASME and is scheduled to be published in 1998, t
e 3.5 ALTERNATIVE EXAMINATION (as stated)
The leak-tightness of seals and gaskets will be tested in accordance with 10 CFR 50,* Appendix J. The 10 CFR 50, Appendix J, Type B testing is performed-at least once each inspection interval.
3.6 EVALUATION l
l The staff position is that penetration seals and gaskets are part of the
' containment pressure boundary. The staff has determined that the licensees' l alternative examination commitment of functionality of the containment l penetration seals and gaskets (including those of electrical penetrations) would be verified during the Type B testing as required by 10 CFR Part 50, Appendix J. In response to the staff's question on the inspection and replacement of seals and gaskets, the licensees provided additional l information as follows::
The Equipment Hatch is removed during maintenance outages, when necessary, and during each refueling outage. Prior to final closure, the hatch gaskets and door sealing face are inspected for damage which could prevent sealing. The Personnel Hatch and Emergency Escape Hatch are included in the Davis-Besse Nuclear Power Station (DBNPS) Preventive l Maintenance Program. This program requires that the door gaskets be-l inspected for damage which could prevent sealing and be coated with an.
approved silicone lubricant to preserve their integrity. These inspections are performed each refueling outage. Prior to establishing containment integrity, the Equipment Hatch, Personnel Hatch, and the l Emergency Escape Hatch are tested in accordance with 10 CFR 50 l
Appendix J to confirm their sealing capability.
l The staff has determined that these actions are adequate to ensure the
! . integrity of the Davis-Besse containment penetration seals and gaskets.
.Therefore, the staff finds the licensees' alternative programs acceptable for granting relief under 10 CFR 50.55a(a)(3)(i) because the proposed alternatives would provide an acceptable level of quality and safety.
4.0~ RELIEF RE0 VEST NO. RR-E{
4.1 SYSTEM / COMPONENT (S) FOR WHICH RELIEF IS RE0 VESTED All components subject to examination in accordance with Subsection IWE of the 1992 Edition,1992 Addenda of ASME Section XI.
4.2 CODE RE0VIREMENTS Subarticle IWA-2300, " Qualification of Nondestructive Examination Personnel,"
requires qualification of nondestructive examination personnel to CP-189 -
1991, " Standard for Qualification and Certification of Nondestructive Testing Personnel," as amended by the ASME Section XI.
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4.3 CODE RE0VIREMENTS FROM WHICH RELIEF IS RE0 VESTED (as stated)
Relief is requested from the provisions of Subarticle IWA-2300, " Qualification of Nondestructive Examination Personnel." This requires NDE personnel to be !
qualified and certified using a written practice in accordance with CP-189, j
" Standard for Qualification and Certification of Nondestructive Testing '
Personnel," as amended by the requirements of Subarticle IWA-2300.
l 4.4 BASIS FOR RELIEF (as stated)
I 10 CFR 50.55a nu 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. In addition to the requirements of Subsection IWE, this also imposes the requirements Subsection IWA, General Requirements, of the 1992 Edition, 1992 Addenda of Section XI. Subarticle IWA-2300, requires qualification of nondestructive examination personnel to CP-109, as amended by Subarticle IWA-2300.
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.A .*itten practice based on the requirements of CP-189, as amended by the requis aments of the Subarticle IWA-2300, to implement Subsection IWE duplicates efforts already in place to for all other subsections. The Davis-Besse Nuclear Power Station Second Ten Year Inservice Inspection Program is written to meet the 1986 Edition, No Addenda of Section XI. Subarticle l IWA-2300 of the 1986 Edition requires a written practice based on SNT-TC-1A, ,
" Personnel Qualification and Certification in Nondestructive Testing," as I amended by the requirements of Subarticle IWA-2300. Further, Subarticle IWA-2300 of the 1992 Edition,1992 Addenda, states, " Certifications based on l SNT-TC-1A are valid until decertification is required."
Visual examination is the primary nondestructive examination method required by Subsection IWE. Neither CP-189 nor SNT-TC-1A specifically includes visual l examination. Therefore, the Code requires qualification and certification to comparable levels as defined in CP-189 or SNT-TC-1A, as applicable, and the
[ employer's written practice. Ultrasonic thickness examinations may also be
! required by Table IWE-2500-1. These examinations are relatively simple and do not require an extensive training and qualification program. Therefore, use of CP-189 in place of SNT-TC-1A will not improve the capability of examination personnel to perform the visual and ultrasonic thickness examinations required by IWE.
Development and administration of a second program would not enhance safety or quality and would serve as a burden, particularly in developing a second written practice, tracking of certifications, and duplication of paperwork.
This duplication would also apply to Nondestructive Examination (NDE) vendor !
programs. Updating to the 1992 Edition, 1992 Addenda, for Subsections IWB, l l IWC, etc., would require a similar request for relief. !
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Relief is requested in accordance with 10 CFR 50.55a(a)(3)(ii). Compliance j with the specified requirements of this section would result in hardship or ]
unusual difficulty without a compensating increase in the level of quality and I safety. l 1
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l The requirement to comply with IWA-2300'has been removed in the rewrite of l Subsection IWE of ASME Section XI. This rewrite has been approved by ASME and l 1s scheduled to be published in 1998.
4.5 ALTERNATIVE EXAMINATIONS (as stated)
Examinations required by Subsections IWE shall be conducted by personnel i qualified and. certified to a written practice based on SNT-TC-1A and the 1986 l Edition, No Addenda, of ASME Section XI. Visual examination personnel will receive specific training in conducting containment examinations.
4.6 EVALUATION l The current Davis-Besse program for qualifying and certifying NDE personnel is based on the 1986 Edition of the ASME Section XI requirements for Class 1, 2, l-and 3. components. -The 1980 edition of the code requires the use of SNT-TC-1A (see Section 4.4) for the qualification and certification of NDE personnel. <
Thus, the staff recognizes that, due to the amendment to 10 CFR 50.55a (see i
, Section 4.4), the licensees will have to develop a second program for l l qualifying and certifying its NDE personnel for containment inspection in L
accordance with Subarticle IWA-2300 of the 1992 Edition of the Code.
Moreover, as pointed out by the licensees, most of the containment examinations required by Subsection IWE are VT-3, general visual. Volumetric
' examination is required during the containment surface augmented inspection.
As the licensees' current procedure for qualifying and certifying the NDE personnel, based on the provisions of SNT-TC-1A, is acceptable for Class 1, 2, and 3 components, the.use of NDE personnel qualified by the procedure for containment augmented examination will not compromise the quality of the
- i. examination. The licensees plan to use CP-189 (see Section 4.2).for l certifying and. qualifying the NDE ' personnel for the next 10-year inspection interval program plan beginning in September 2000.
As the VT-3 visual examination is the basic examination technique for containment inspection, the licensees have developed procedures for (1) qualification of the visual examination personnel for vision tests and (2)
, illumination requirements in accordance with IWA-2320 of the 1992 Edition and
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Addenda, as modified by the rule.
Considering these factors, the staff concludes that the imposition of the requirement of Subarticle IWA-2300 (1992 Edition) for containment inspection will subject the licensees to hardship without a compensating increase in the level of quality and safety. The alternative proposed will provide an acceptable level of quality and safety. Hence, the staff finds this relief request acceptable pursuant to 10 CFR 50.55a(a)(3)(ii).
. 5.0 RELIEF RE0UEST NO. RR-E3 5.1 SYSTEM / COMPONENT (S) FOR WHICH RELIEF IS RE0 VESTED
- All Class MC, Subarticle IWE-2200(g), preservice examination requirements of reapplied painted or coated containments.
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5.2 [0DE 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 or coating shall'be documented in the preservice examination records.
5.3 s20E REQUIREMENT FROM W!i1CH RELIEF IS REQUESTED (as stated)
Relief is requested from the requirement to perform a preservice inspection of new paint or coatings.
5.4 BASIS FOR RELIEF fas_gatf,1).
Paint and coatings are not part of the containment pressure boundary under
! current Code rules ~as they are not associated with the pressure retaining function of the' component (Paragraph NE-2110 (b)(5) of ASME Section III).
y Neither paint nor coatings contribute to the structural integrity. or leak
! tightness of 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 Y.I rules for repair or i
replacement in accordance with IWA-4111(b)(5). The adequacy of applied coatings is verified through the inspections performed by the Davis Besse Nuclear Power Station (DBNPS) coating maintenance program.
Recording the condition of reapplied coating in the preservice record does not l substantiate the containment structural integrity. Should deterioration of the coating in the reapplied area occur, the area will require additional evaluation regardless of the preservice record. Recording the conditlon of new paint or coating in the preservice records does not increase the level of i quality and safety of the containment.
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.37, 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 I
sufficient." This is currently accomplished through the inspections performed by the DBNPS coating maintenance program.
l Relief is requested in accordance with 10 CFR 50.55a(a)(3)(i). The DBNPS coating maintenance program currently provides an adequate level of quality and safety.
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 by ASME and is scheduled to be l published in 1998. l l
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r 5.5 ALTERNATE EXAMINATIONS (as stated) l Reapplied paint and coatings on the containment vessel will be examined in L
accordance with'the DBNPS coatings program. Although repairs to paint or coatings are not subject to the repair / replacement rules of ASME XI i
(Inquiry 97-22), repairs to the primary containment boundary, if required, would be conducted in accordance with ASME Section XI Code rules.
5.6 EVALUATION The staff does not agree with the licensees' perception t' tat the quality and integrity of the paint applied to containment surfaces are not relevant to the i
containment's functional integrity.. In Table 3 of the Final Rule (SECY 96-080), there are numerous examples where the containment integrity was l found questionable because of the degradation of the applied paint and coating, and corrosion of the metal.
In response to the staff's question on the DBNPS coating program, the l
licensees indicated that the containment coating (interior surface) is applied and inspected in accordance with the NRC-approved quality assurance program.
According to the licensees, the following requirements are applicable for l coatings applied to the interior surface of'the containment vessel:
The quality assurance requirements of Section 3 of ANSI N101.4 applicable to the coating manufacturer are imposed on the coating manufacturer through the procurement process.
Coating application. procedures are developed based on the manufacturer's
. recommendations for application of the selected coating systems.
Coating applicators are qualified to demonstrate their ability to satisfactorily apply the coatings in accordance with the manufacturer's recommendations.
l Quality Control personnel perform ~ inspections to verify conformance of the coating application procedures. Section 6 of ANSI N101.4 is used as a guideline in the establishment of the inspection program.
Quality Control inspection personnel are qualified to the requirements of Regulatory Guide 1.58, Rev 1.
! Documentation demonstrating conformance to the above is maintained.
The condition of the coatings are [ sic] examined every 4 to 6 years in accordance with 10 CFR 50.65, " Requirements for Monitoring Effectiveness of Maintenance at Nuclear Power Plants." The general visual examination required by IWE is also performed each period.- These periodic l examinations will identify evidence of flaking, blistering, peeling, l
discoloration, or other signs of coating distress which might be indicative of degradation of the containment structural integrity.
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This program is presently being evaluated against the recommendations of i Information Notice (IN) 97-13 " Deficient Conditions Associated with Protective Coatings at Nuclear Power Plants," and the Electric Power R l
Research Institute (EPRI) Plant Support Engineering Guidelines for Nuclear Safety Related Coatings. Changes to improve this program will be implemented as necessary.
The staff considers the alternative program, as stated by the licensees, for application of paint or coating, its inspection and its quality assurance provisions acceptable for protecting the inside steel surfaces of the Davis-
. Besse containment. .Therefore, relief is . granted pursuant to 10 CFR ;
50.55a(a)(3)(1) as the alternative would provide an acceptable level of l quality and safety.
6.0 RELIEF RE0 VEST NO. RR-E4 6.1 SYSTEM / COMPONENT (S) FOR WHICH RELIEF IS RE0 VESTED All Class MC, Subarticle IWE-2500(b) visual examination per Table IWE-2500-1 ,
l of painted or coated containment components prior to removal of paint or coatings.
6.2 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.
6.3 CODE RE0VIREMENT FROM WHICH RELIEF IS RE0 VESTED (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.
6.4 B_ ASIS FOR RELIEF (as stated)-
L 10 CFR 50.55a was amended, as cited in the federal Register (61 FR 41303), to l require the use of the 1992 Edition, 1992 Addenda, of ASME Section XI when performing containment examinations. Paint and coatings are not part of the containment pressure boundary under current Code rules as they are not associated with the pressure retaining function of the component (Paragraph NE-2110 (b)(5) of ASME Section III). The interiors of containments are painted to prevent rusting. Neither paint nor coatings contribute to the structural integrity or leak tightness of 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 i would be an indicator of potential degradation of the containment pressure l
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 a ASME
Section XI repair or replacement activity, is a burden without a compensating increase in quality or safety.
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(i). Coating inspection programs currently provide an adequate level of quality and safety.
The requirement to inspect coatings prior to removal has been removed in the I rewrite of Subsection IWE of ASME Section XI. This rewrite has been approved by ASME and is scheduled to be published in 1998. l 6.5 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 DBNPS Maintenance Program. 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.
6.6 EVALUATION As indicated in the staff evaluation of RR-E3, the staff finds that the Davis-Besse coating program 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 the licensees' program subjected to the quality assurance requirements of 10 CFR Part 50 Appendix B) would be a burden without a compensating increase in quality or safety. Therefore, the staff finds the licensees' alternative i coating program acceptable for granting relief from the requirement of j Subarticle IWE-2500(b) of the Code pursuant to 10 CFR 50.55a(a)(3)(i). 1 7.0 RELIEF REOUEST NO. RR-E5 7.1 SYSTEM / COMP 0NENT(S) FOR WHICH RELIEF IS RE0 VESTED All components subject to the rules and requirements for repair, replacement or modification of Class MC, IWE-5000 system pressure testing visual examination in accordance with the 1992 Edition,1992 Addenda of ASME Section XI.
7.2 CODE REQUIREMENT (S)
Paragraph IWE-5240, " Visual Examination," of the 1992 Edition,1992 Addenda, of ASME Section XI, requires that the requirements of Paragraph IWA-5240,
" Visual Examination," for visual examination, VT-2, are applicable following repair, replacement, or modification.
7.3 CODE RE0VIREMENT FROM WHICH RELIEF IS RE0 VESTED (as stated)
Relief is requested from performing the VT-2 visual examination in connection with system pressure testing following repair, replacement or modification under Article IWE-5000, " System Pressure Tests."
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7.4 BASIS FOR RELIEF (as stalgd1 Repair / replacements are performed in accordance with the Lavis Besse Nuclear Power Station (DBNPS) repair / replacement program which specifies the repair methods and nondestructive examinations necessary to ensure the original l- quality'and construction requirements of the containment vessel are met.
1 L 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 ASME Section XI when performing. containment examinations. Paragraph IWE-5210 states that, except as noted within Paragraph IWE-5240, " Visual Examination," the requirements of Article IWA-5000 are not applicable to Class MC or Class CC components.
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Paragraph IWE-5240 states that, the requirements of Paragraph IWA-5240
'(corrected from IWA-5246 to IWA-5240 in the 1993 Addenda) for visual l examinations are applicable. , Paragraph IWA-5240 describes a VT-2 visual I
examination. VT-2 examinations are conducted to detect evidence of leakage l
from pressure retaining components, with or without leakage collection systems, as required during the conduct of a system pressure test. In addition, personnel performing VT-2 examinations are required to be qualified in accordance with Subarticle IWA-2300, " Qualification of Nondestructive
- Examination Personnel," of ASME Section XI.
l Table IWE-2500-1, Examination Category E-P, specifies the examination method of 10 CFR 50, Appendix J following each repair, modification, or replacement and does not specifically identify a VT-2 visual examination. 10 CFR 50,
, Appendix J provides requirements for testing as well as acceptable leakage l criteria. These tests are performed by qualified personnel- and utilize calibrated equipment to determine acceptability. Additionally,10 CFR 50.55a(b)(2)(x)(E) requires a general visual examination of the containment each period that would identify any structural degradation that may contribute to _ leakage. A VT-2 visual examination will net provide additional assurance of safety beyond that of current repair / replacement and 10 CFR 50 Appendix J practices.
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(i). Pressure testing in accordance with 10 CFR 50, Appendix J, provides an adequate level of quality.
7.5 ALTERNATIVE EXAMINATIONS (as stated)
Testing and examination shall be conducted in accordance with 10 CFR 50, Appendix J. A preservice visual examination will be performed on the
! repair / replacement [R/R).
I 7.6 EVALUATION The purpose of 10 CFR 50.55a(b)(2)(x)(E) is to assess the surface condition of the containment. -It does not relate to the Code requirement in IWE-5240.
Moreover, this provision is related to the repair / replacement (R/R) aspect of the containment system. As clarified in NRC Information Notice 97-29, l " Containment Inspection Rule," the IWE and IWL requirements for R/R became effective September 9, 1996. The staff had considered relief from the R/R l
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requirements up to' September 9,1997 as reasonable. As the licensees hail not requested relief from this provision ,during that time, the staff assumed that the licensees were complying with Code requirement for R/R activities. rhe staff finds that a VT-2 examination of the pressure retaining components after major R/R activities involving these components is an assurance of the integrity of the component. The licensees have not made an acceptable case pursuant to either 10 CFR 50.55a(a)(3)(i) or (a)(3)(ii) to substantiate the relief request. Therefore, the staff denies the requested relief.
8.0 EfMIF REQUE h0, RR-E6 8.1 Eilfji/1Qt@NENTIS) FOR WHICH RELIEF IS RE0UESTED 1All Class MC, Paragraphs IWE-2420(b) and IWE-2420(c) successive examination l requirements for components found acceptable for continued service. !
8.2 QDLBfE1EMENT/S)
Paragraphs IWE-2420(b) and IWE-2420(c) of the 1992 Editicn, 1992 Addenda of l 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 i found to be acceptable for continued service, the areas containing such flaws, !
degradation, or repairs shall be reexamined during the next inspection period I listed in the schedule of the inspection program of Paragraph IWE-2411',
" Inspection Program A," or Paragraph IWE-2412, " Inspection Program B," in accordance with Table IWE-2500-1, Examination Category E-C.
8.3 CODE REQUIREMENT FROM WHICH RELIEF IS RE0 VESTED (as steted)
Relief is requested from the requirement of Paragraphs IWE-2420(b) and IWE-2420(c) to perform successive examination of repairs.
I 8.4 BASIS FOR RELIEF (as stit14). I 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 j 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, i 1996, response to comment # 3.3 states "The purpose of IWE-2420(b) is to l
, manage components found to be acceptable for continued service (meaning no j l- repair or replacement at this time) as an Examination Category E-C i component... If the component had been repaired or replaced, then the more l frequent examination would not be needed."
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(ii). Compliance L with the specified requirements of this section would result in hardship or l unusual difficulty without a compensating increase in the level of quality and safety.
The requirement to perform successive examinations following repairs has been i
removed in the rewrite of Subsection IWE of ASME Section XI. This rewrite has been approved by ASME and is scheduled to be published in 1998.
8.5 ALTERNATE EXAMINATIONS (as stated)
Successive examinations in accordance with Paragraphs IWE-2420(b) and l IWE-2420(c) are not required for repairs made in accordance with Article '
IWA-4000. ,
8.6 EVALUATION As the Code requires the licensees to verify the adequacy of repairs, the staff has determined that successive examinations after repair do not provide an additional safety benefit. In' response to the staff's question on whether the relief request _also includes a relief from the successive examinations when the flaws and degradations are accepted by " engineering analysis," the licensees clarified that the relief only applies when the flaws or degradations are corrected by repairs. As pointed out in the staff evaluation of RR-E5, the licensees should have sought the relief from these requirements prior to September 1997. However, considering the hardship associated with these requirements without a compensating increase in the level of quality and safety, the staff finds that relief from the Code requirements of IWE-2420(b) and IWE-2420(c) is acceptable pursuant to 10 CFR 50.55a(a)(3)(ii).
9.0 RELIEF RE0 VEST'NO. RR-E7 9.1 SYSTEMS / COMPONENTS FOR WHICH RELIEF IS RE0 VESTED Class MC pressure retaining bolting.
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9.2 CODE RE0VIREMENT(S)
ASME Section XI, 1992 Edition with the 1992 Addenda, Table IWE-2500-1, Examination Category E-G, Pressure Retaining Bolting, Item 8.20.
9.3 CODE RE0VIREMENT FROM WHICH RELIEF IS RE0 VESTED (as stated)
\
Relief is 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.
9.4 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 ASME Section XI when 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 un-torqued 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). Un-torquing 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.
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 by ASME and is scheduled to be published in 1998.
9.5 ALTERNATE EXAMINATION (S) (as stated) l The following examinations and tests required by Subsection IWE ensure the structural integrity and the leak-tightness of Class MC pressure retaining l bolting, 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 Retaining Components, Item E9.40.
9.6 EVALUATION In response to the staff's question on the number of pressure unseating penetrations where bolts are used to keep the seals and metal surfaces leaktight, the licensees indicated that there are no pressure unseating i penetrations in the Davis-Besse containment. 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 commensurate increase in the level of safety or quality. Therefore, the staff finds that the relief is acceptable pursuant to 10 CFR 50.55a(a)(3)(ii).
10.0 RELIEF RE0 VEST NO. RR-E8 10.1 SYSTEM / COMPONENT (S) FOR WHICH RELIEF IS RE0 VESTED All components subject to examination in accordance with Subsection IWE of the j 1992 Edition, 1992 Addenda of ASME Section XI. j 10.2 CODE RE0VIREMENTS Subarticle IWA-2210 provides requirements for visual examination procedures.
10.3 CODE RE0VIREMENTS FROM WHICH RELIEF IS RE0 VESTED (as stated) :
Relief is requested from the provisions of Table IWA-2210-1, Visual Examinations. Tat,le IWA-2210-1 requires direct visual VT-3 examinations be !
performed with a minimum illumination of 50 fc, and at a maximum examination j distance of 4 feet. The procedure must be demonstrated to resolve a lower i case character height of 0.105 inches. l
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l 10.4 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 ASME Section XI when performing containment examinations. In addition to the requirements of Subsection IWE, this [ amendment] also imposes the requirements of the 1992 l
i 3
Edition, 1992 Addenda of Subsection IWA for containment examinations. For remote examination, this amendment to 10 CFR 50.55a permits the maximum direct examination distance specified in Table IWA-2210-1 be extended and the minimum illumination requirements specified in Table IWA-2210-1 decreased provided that the conditions or indications for which the visual examination is performed can be detected at the chosen distance and illumination. When
! performing a VT-3 examination of coated areas, IWE-3510.2, "VT-3 Visual l-Examinations on a Coated Areas," requires the area be inspected for evidence of flaking, blistering, peeling, discoloration, and other signs of distress.
The Davis Besse Nuclear Power Station (DBNPS) containment vessel is coated.
Approximately 15% of the containment surface is within the maximum 4 foot examination distance necessary to perform a direct visual VT-3 examination.
The remainder must either be examined from scaffold.or by remote examination.
In several areas, remote examination is difficult due to the proximity of the remote examination to the containment surface. Distortion of the viewing area occurs when using optical aids which magnify the area of interest. Many of these areas also do not contain sufficient room to erect scaffold within 4 feet of the containment vessel. In other areas, scaffold would restrict normal access and egress routes for personnel working in containment.
I Direct visual VT-3 examinations will be performed to the same distance and illumination requirements as for remote visual examinations. That is, direct VT-3 examinations will be performed at distance and minimum illumination distances which will detect the conditions or indications for which the visual examination is being performed. The direct VT-3 examination will be equivalent to the remote examination.- Both the direct VT-3 examinations and the remote VT-3 examinations will be capable of detecting flaking, blistering, i peeling discoloration, or other signs of distress of coated containment vessel.
As recognized in the amendment to 10 CFR 50.55a, the Table IWA-2210-1 VT-3 distance, illumination and-qualification requirements are not necessary to 1 identify conditions which may affect the containment structural integrity. '
Use of the remote examination criteria for direct visual examinations will eliminate the need to build scaffold or use remote examination when the direct l examination will detect the same conditions as would be identified through remote examination, j 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 by ASME and is scheduled.to be published in 1998.
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t 10.5 ALTERNATIVE EXAMINATIONS (as stated)
VT-3 visual examinations will be performed under distance and illumination requirements necessary to detect the conditions or indications for which the visual examination is performed. The examination procedure will be demonstrated capable of detecting these conditions.
10.6 EVALUATION t
Considering the size of- the containment structures (as compared to Class 1, 2 and 3 components), and recognizing the varied lighting conditions, the staff provided latitude to the licensees from the requirement of IWA-2216 for VT-3 remote visual examination. For direct visual examination, the Code requirements in Table IWA-2210-1 are practical and have been used for Class 1,--2 and 3 components for a-number of years. ' The staff does not ,
consider these requirements for direct visual examination a hardship. The i requested relief is denied. I 11.0 ELIEF REQUEST NO. RR-FJ 11.1 }lSTEM/ COMPONENT (S) FOR WHICH RELIEF IS RE0VESJ1Q l
l Surface areas' subject to augmented examination in accordance with Subsection IWE of the 1992 Edition, 1992 Addenda of ASME Section XI.
11.2 CODE REQUIREMENTS ASME Section XI, 1992 Edition, 1992 Addenda, Subarticle IWE-2500(c)(3) requires one foot square grids be used when ultrasonic thickness measurements are performed on augmented examination surface areas. The number and location of the grids is determined by the Owner. Subarticle IWE-2500(c)(4) requires the minimum wall thickness within each grid be determined.
l 11.3 CODE RE0UIREMENTS FROM WHICll RELIEF IS RE0 VESTED (as stated)
Relief is requested from using one foot square grids for augmented examination areas and the requirement to determine the minimum wall thickness within each
! grid, 11.4 BASIS FOR RELIEF (as stated)
Subarticles IWE-2500(c)(3) and IWE-2500(c)(4) of the 1992 Edition, 1992 Addenda of ASME Section XI, require'that the minimum thickness within each one
( , foot square grid of surface areas requiring augmented examination be marked L ' such that periodic reexamination of that location can be performed. Thickness readings are point readings. Numerous readings are necessary to identify the minimum thickness within each grid. This only identifies the thinnest area.
Periodic examination of the minimum thickness point only monitors that point. l It may not be the area that is the most susceptible to accelerated degradation.
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The attached Table RR-E9, " Ultrasonic Thickness Measurements for Augmented Examination," provides the proposed alternative to the one foot square grid area required by IWE-F.)](c)(3). Table RR-E9 requires examination at the grid line intersections. T..a grid line intersections may not exceed 12 inches and may be as small as 2 inches.
For a sample area of 50 square feet, Table RR-E9 requires a minimum 100 l locations be monitored. For a sample area of 50 square feet, IWE-2500(c)(3) would require only 50 locations be monitored. In this instance, utilizing Table-RR-E9 monitors more locations than required by IWE-2500(c)(3).
For sample areas greater than 100 square feet, Table RR-E9 requires that sufficient points be monitored to ensure at least a 95% confidence level that the thickness of the base metal is reduced by no more than 10% of the nominal plate ~ thickness at 95% of the grid line intersections. . Table RR-E9 also requires additional examinations when any measurements reveal wall thickness is reduced by more than 10% of the nominal plate thickness.
I For all examination areas, should the measurements at a grid line intersection i reveal that the base material is reduced by more than 10% of the nominal plate ;
thickness, Table RR-E9 requires the minimum wall thickness within each '
adjoining grid be determined. This is similar to the examination requirements of IWE-2500(c)(4) except that Table RR-E9 focuses resources on areas which l have-exhibited degradation rathei nan areas which have not exhibited degradation.
The Flow Accelerated Corrosion programs presently in place have proven that taking thickness readings at grid intersections are effective in monitoring wall thinning of piping.
Relief is requested.in accordance with 10 CFR 50.55a(a)(3)(ii). Taking numerous ultrasonic thickness readings within a grid which had not exhibited degradation results in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
The requirements of Table RR-E9, except for note 1, have been incorporated into the rewrite of Subsection IWE of ASME Section XI. This rewrite has been approved by ASME and is scheduled to be published in 1998. Note 1 is contained within a draft ASME Code Case which has been approved by L Subcommittee on Nuclear Inservice Inspection.
11.5 ALTERNATIVE EXAMINATIONS (as stated)
Table RR-E9 (see licensees' letter dated Deceaoer 22,1997) will be used to determine examination requirements for ultrasonic thickness measurements of L
areas' requiring augmented examination.
11.6 EVALUATION The staff has determined that _the proposed examinations (specifically the f requirement to conduct examinations at grid line intersections as stated in Table RR-E9) provide an accepi.able alternative to the Code requirements in
IWE-2500(c)(3) and IWE-2500(c)(4). As the Code requirements would require the licensees.to take numerous thickness readings within a grid which had not exhibited degradation, the licensees are requesting this relief pursuant to 10 CFR 50.55a(a)(3)(ii). The staff finds the request for relief acceptable pursuant to 10 CFR 50.55a(a)(3)(ii) as compliance with the code requirements would result in undue hardship or unusual difficulty without a compensating increase in the icvel of quality and safety.
12.0 RELIEF RE0yEST NO. RR-E10 12.1 SYSTEM / COMPONENT (S) FOR WHICH RELIEF IS REQUESTED All Class MC pressure retaining components.
12.2 CODE REQUIREMENTS ASME Section XI, 1992 Edition, 1992 Addenda, Subsection IWE.
12.3 CODE RE0VIREMENTS FROM WHICH RELIEF IS RE0 VESTED (as stated)
Implementation of the 1992 Edition,1992 Addenda of ASME Section XI for examination of Class MC components requires the use of Subsection IWA-4000 of the 1992 Edition, 1992 Addenda of ASME Section XI for repairs and' replacements to Class MC components.
12.4 BASIS FOR RELIEF (as stated)
In the Federal Register dated August 8, 1996, (61 FR 41303), the NRC amended its' regulations to incorporate the 1992 Edition, 1992 Addenda of ASME Section XI when performing containment examinations. In addition to the requirements of Subsection IWE, this also imposes the requirements of the 1992 Edition, 1992 Addenda of Subsection-IWA-4000, " Repair and Replacement," for containment repairs and replacements.
Toledo Edison holds a National Board Nuclear Repair Certificate of Authorization for repairs / replacements to Class 1, 2, 3, and MC components.
This Certificate of Authorization is based on the Davis Besse Nuclear Power Station (DBNPS) Repair / Replacement program which is written to the requirements of the 1986 Edition, No Addenda, of ASME Section XI. This program requires that repairs and replacements to the containment vessel meet its design specifications and Construction Code requirements. This ensures that the original integrity and quality of the containment vessel will be maintained during repair / replacement activities.
Meeting both the 1986 Edition, No Addenda, and the 1992 Edition,1992 Addenda of ASME Section XI requires the maintenance of two separate repair and replacement programs (one for the IWB, IWC, and IWD components per the 1986 Edition, No Addenda of ASME Section XI and one for the containment vessel per the 1992 Edition,1992 Addenda of ASME Section XI). Duplicate records to demonstrate compliance with the 1986 Edition, No Addenda, and the 1992 Edition,1992 Addenda, will also be required. This duplication of programs and records increases the man-hours necessary to maintain the DBNPS.
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Repair / Replacement Program without providing any increase in quality of containment vessel repairs / replacements.
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(I) (sic). The DBNPS repair / replacement program ensures that the original integrity and quality of the containment vessel is maintained during repair / replacement activities.
12.5 ALTERNATIVE EXAMINATION (as stated)
The DBNPS Repair / Replacement Program, written to the requirements of 1986 Edition, No Addenda of ASME Section XI, will be used for repairs and replacements to the containment vessel. Preservice examinations will be conducted in accordance with the requirements of Subsection IWE of the 1992 Edition,1992 Addenda of ASME Section XI.
12.6 EVALUATION As pointed out in the staff evaluation of RR-E5, the licensees were supposed to be in compliance with the Rule since September 9,1996 for repair and replacement activities. Also, unless a comprehensive comparison of IWA-4000 in 1992 Edition and Addenda and that in 1986 Edition of the Code is performed, and the extent to which those provisions are incorporated in the Davis-Besse repair / replacement procedures is described, the staff can not make an assessment regarding the merits of the alternative proposed in context of 10 CFR 50.55a(a)(3)(i). Therefore, the staff denies this relief request.
13.0
SUMMARY
A summary of the above evaluations is provided in the attached Table (Enclosure 2).
Principal Contributor: H. Ashar Date: June 30, 1998
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