ML20209F347

Forwards Response to NRC 990624 RAI to Complete NRC Review of Relief Request to Allow Use of 1998 Edition of ASME Section Xi,Subsection IWE

ML20209F347
Person / Time
Site:	Callaway
Issue date:	07/09/1999
From:	Passwater A UNION ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
TAC-MA4598, ULNRC-4063, NUDOCS 9907150295
Download: ML20209F347 (8)

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Union Etoctric

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• One Ameren Plaza 1001 Chouteau Avenue '

PO Box 66149 l St. Louis, MO 63166-6149 31U211222 July 9,1999 U. S. Nuclear Regulatory Commission Attn: Document ControlDesk Mail Stop PI-137 Washington, DC 20555-0001 Gentlemen: ULNRC-4063

[4 TAC NO. MA4598 WAmeteri DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT I UNION ELECTRIC CO.

FACILITY OPERATING LICENSE NPF-30 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ON RELIEF REQUEST TO ALLOW TIIE USE OF TIIE 1998 EDITION OF ASME SECTION XI, SUBSECTION IWE

References:

(1) ULNRC-3938, dated January 11,1999 (2) Letter dated June 24,1999 from J. N. Donohew, NRC, to G. L. Randolph AmerenUE requested relief to use the 1998 Edition of ASME Section XI, /

Subsection IWE in lieu of the 1992 Edition and 1992 Addenda of the Code via Reference 1. The NRC staffreguested additional information to complete their ruiew of this relief request be provided within 30 days in Reference 2. The requested information is provided in the Attachment to this letter. L/

If you have any questions concerning this response, please contact us.

Very truly yours, ctt Alan C. Passwater Manager, Corporate Nuclear Services BFH\jdg Attachments 9907150295 990709 PDR ADOCK 05000483 P PDR e subsidiary of Amoren Corporation

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I i STATE OF MISSOURI )

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CITY OF ST. LOUIS-)

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i Alan C. Passwater, of lawful age, being first duly sworn upon oath says that he is Manager, Corporate Nuclear Services for Union Electric Company; that he has read the foregoing document and knows the content thereof; that he

has executed the same for and on behalf of said company with i full power and authority to do so; and that the facts l therein stated are true and correct to the best of his l knowledge, information and belief.

By Alan C. Passwater Manager, Corporate Nuclear Services SUBSCRIB nd swnrn to before me this /b day of , 1999.

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'cc: M. H. Fletcher Professional Nuclear Consulting, Inc 19041 Raines Drive

Derwood, MD 20855-2432' Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan. Plaza Drive

' Suite 400 Arlington,,TX 76011-8064 Senior Resident Inspector.

Callaway Resident Office U.S. Nuclear. Regulatory Commission 8201 NRC' Read Steedman, MO 65077 Mr. Jack Donohew (2)'

Office of Nuclear Reactor Regulation-U.S. Nuclear Regulatory Commission 1 White Flint, North, Mail Stop 13E16 11555 Rockville Pike' Rockville, MD 20852-2738 Manager, Electric Department Missouri Public Service Commission P.O. Box 360 ,

Jefferson City, MO 65102 l 1

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ULNRC-4063 Attachment 1 Page 1 of 5 l REQUEST FOR ADDITIONAL INFORMATION  !

CALLAWAY PLANT l ASME SECTION XI, SUBSECTION IWE By Nuclear Regulatory Commission letter dated June 24,1999 to Mr. Garry L. Randolph of ,

Callaway Plant, a request for additional information concerning AmerenUE's relief request to use l tl.e 1998 Code of ASME Section XI, Subsection IWE was submitted. Following is a summary i of the information requested and Callaway Plant's iesponse to each item.  ;

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1. The 1998 Edition of the ASME Ccde (the code),Section XI generally refers to IWA-2000,

" Examination and inspection," when defining the general requirementsfor examinations to be performed, andfor the quahfication of examination personnel. The proposed alternative removes the IWA-2300 requirement to certify NDEpersonnel to CP-189. In addition, new code examinations (General Visual and Detailed Visual) have been introduced in Subsection IWE of the 1998 Edition of the code. The definition of the new Code examinations has been left up to individual licensees, and a licensee would be allowed to define howpersonnelperforming these examinations are to be quahfied. To establish that the alternative provides an acceptable level ofquality and safety, additional information on the licensee's general and detailed visual examination is needed. Please provide a description of ~urplant specific visual examination program, including attributes such as: Details of th. owner-defined general visual examination, acceptance criteria, that will be used to examine containment liner surfaces, containment 1 welds, pressure retaining bolting, moisture barriers, and dissimilar metal welds, etc.

A " general visual" examination will be performed on 100% of the pressure boundary at Callaway Plant every period. This is required both by the 1998 code as well as the 10 CFR 50.55a(x)(E).

The 1992 code specifies that the general visual examination "shall be performed by, or under the direction of, a Registered Professional Engineer or other individual, knowledgeable in the requirements for design, inservice inspection, and testing of Class MC and metallic liners of Class CC components. The examination shall be performed either directly or remotely, by an examiner with visual acuity sufficient to detect evidence of degradation that may affect either the containment structural integrity or leak tightness." The 1998 code states that the " Owner shall define requirements for visual examination of containment surfaces." At Callaway Plant, the general visual inspection will be performed by a qualified NDE QC inspector certified to CP-189. This inspection will be made from existing floors, platforms and vantagepoints to cover the entire pressure boundary. Ladders may be required in some cases to allow the inspector to view the upper side of penetrations or other features. Liner plate welds and dissimilar metal welds will not be inspected as a separate item, but will be covered under the general visual inspection. This

ULNRC-4063 I. .

Attachment 1 l Page 2 of 5 is in accordance with 10 CFR 50.55a(x)(C). Pressure retaining bolting, that is not disassembled during the period, will be inspected under the general visual inspection. Bolted connections that are disassembled anytime during the period are subject to a VT-1 inspection in accordance with the 1998 Code of ASME Section XI, Subsection IWA, Article 2000. Callaway Plant does not l

have any moisture barriers so that is not an issue here. Acceptance criteria for the general visual examination under the 1992 code was " degradation that may affect either the containment structural integrity or leak tightness." The 1998 code states that the owner shall define the acceptance criteria. At Callaway Plant the inspectors will be looking for excessive corrosion, blistered, flaking. or peeling paint, general deformation, bulges or other signs of distress. If the acceptance criteria are not met, a detailed inspection would be performed. At Callaway Plant that will be a VT-3 or VT-1 inspection as defined in the 1998 Code of ASME Section XI, Subsection IWA, Article 2000. These inspections will also be performed by qualified NDE QC inspectors, certified to CP-189.

l 2. UE letter dated January 11,1999, states, "Ameren UE would employ a detailed visual examination such as a W-1 or W-3 depending on the conditions to assure structural integrity of the pressure boundary. " Will the detailed visual examination incorporate existing W-1 and W-3 examination requirements? Ifso, will the personnelperforming these examinations be W-1 or W-3 quahfied? Ifexisting W-1 or W-3 requirements will not be used, describe the detailed visual criteria used to address augmented examinations. Please discuss how these examinations willprovide an equivalent level of quality and safety that is provided by the W-1 and W-3 examinations required by the 1992 Edition and Addenda.

Yes, the detailed visual examinations at Callaway Plant will incorporate the VT-1 or VT-3 examination requirements, depending on the conditions, as defined in ASME Section XI, Subsection IWA-2000,1998 code.

3. Describe the quahfication requirementsforpersonnelperforming containment visual examinations.

The general visual examination will be performed by an NDE certified QC inspector, certified to ANSI /ASNT CP-189. All VT-1 and VT-3 inspections will be performed by NDE QC inspectors certified to ANSI /ASNT CP-189 standards.

ULNRC-4063 Attachment 1 l- Page 3 of 5 l 4. Describe your requirementsfor quahfying IWE visual examination procedures to be l performed and how illumination and resolution requirements will be established and l implemented consistently.

l A general visual examination does not have specific light requirements associated with it in

either the 1992 code or the 1998 code. The 1992 code states that the examination shall be l performed by an inspector with " visual acuity sufficient to detect evidence of degradation that l may affect either the containment structural integrity or leak tightness." The 1998 code states that

! the owner shall define these requirements. Callaway Plant has established acceptance criteria for l the general visual examination. The procedures to assure that the acceptance criteria can be seen and or detected by the inspector in containment are currently under development. It procedure

- will involve the use of a " general visual reference standard" representative of defects or

! deterioration which may be experienced. The reference standard will be placed in representative locations during the inspection and it will be verified that lighting and magnification (when used) are adequate for the inspector to identify the defects. This process is required whether using the 1992 code or the 1998 code. The VT-1 and VT-3 standards are well defined in ASME Section XI, Subsection IWA and will be used as defined in the 1998 Code of ASME Section XI, Subsection IWA, Article 2000.

? 5. The IWE-2500(b) requirement to examine paint or coatings prior to removal has been l eliminatedfrom the 1998 Edition. Alternatives to this requirement have beenfound i

! acceptable when adequate provision exist, in either the licensee's containment inspection, 1 repair / replacement, nuclear coatings, or 151 programs, to examine the base metalfor surface anomalies that may indicate underlying conditions which could challenge the structuralintegrity ofcontainment. The examinations should be performedprior to re-application of the coating, and should invoke detailed visual examinations (e.g., VT-1 or VT-3) or augmented ultrasonic examination, as necessary. In addition, the base metal examination should be performed by quahfied inspection personnel. Provide information addressing the base metal examination prior to paint or coating application.

The entire liner plate at Callaway Plant has been painted, therefore, all coated surfaces will have a general visual examination every period. If the liner plate meets the general visual examination l acceptance criteria, no further examinations would be required and the coating would not be removed. If an area does not meet the general visual acceptance criteria the area will be subjected to a more detailed inspection. A failed general visual examination will have already determined that a potential problem exists. The acceptance criteria for the detailed inspection, which will be discussed in item 6, will require that the failed coating and loose rust be removed in order to determine if the liner plate meets the acceptance criteria of the detailed inspection.

Based on the above, additional steps to inspect coatings prior to removal are not necessary.

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ULNRC-4063 Attachment 1

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6. UE letter dated January 11,1999, states that metallic liners of Class CCpressure retaining components are not subject to the same requirements as Class MC containments (IWE 3511.3,1998 Edition of the Code), therefore, the 10% materialloss is not significant. Ilowever, alternative acceptance criteria, based on the discontinuity effects of thickness differences and anchor spacing, have not been defined. Is it the intent of the Callaway Plant not to document or perform supplemental examinations of the liner when loss ofmaterial has been detected? Describe when and how the supplemental examinations (as required by IWE-3200) of the liner will be performed and the 1 associated acceptance criteria that will be used. Please refer to NRC Information Notice 97-10, " Liner Plate Corrosion in Concrete Containments."for relevant information.

I The metallic liners of Class CC structures are not structural eleme'its of the containment building. The design code (ASME SECTION III, CC-3000 & BC-TOP-05A) prohibits the inclusion of the liner plate as a structural element. The liner plate provides two functions. Its first function was to serve as a concrete form during construction of the containment building.

The stiffness required to support the fresh concrete loads dictated the minimum thickness of the liner plate. This function is no longer needed because the concrete will now support all structural loads, including embed loads. The second and primary function of the liner is to provide a pressure barrier. Any pressure applied to the liner will immediately be transferred to the concrete structure behind it resulting in a maximum load on the plate of only 60 psi. As long as there are no holes in the liner plate the leak tightness would be maintained. Callaway Plant, however, has analyzed the liner plate assuming various size voids in the concrete to determine acceptance criteria beyond a simple 10% reduction in thickness. Request For Resolution (RFR) 19682 A was written to determine maximum acceptable generic wall thinning at Callaway Plant.

Based on the engineering calculations for liner plate loads, a set of acceptance criteria was established. This acceptance criteria will be employed during detailed examinations to determine if the liner plate is acceptable. Any areas not meeting the acceptance criteria will be subject to further evaluation or re; Jr/ replacement. The results of the examinations will be documented and included in the final report for the IWE inspection.

Acceptance criteria for liner plate thinning as determined by calculation is as follows:

• Concrete voids up to 5" in diameter - 1/8" deep defects acceptable.

• Concrete voids greater than 5" in diameter but less than 7" in diameter - 3/16" deep defects are acceptable.

• Localized defects such as gouges less than 1/8" deep are acceptable, provided the length of the defect is limited to 5".

• Localized defects, such as pitting,1/16" deep are acceptable.

l l Voids in the concrete will be identified by sounding the liner plate.

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ULNRC-4%3 Attachment 1 l Page 5 of 5 1

7. In the 1998 Edition of the code, Examination Category E-G, " Pressure Retaining Bolding," has been removedfrom Table IWE-2500-1. The 1992 Edition required VT-1 visual examination ofbolting when a connection was disassembled. The 1998 Edition requires a general visual examination, with no requirement when thejoint is dissembled.

- As a basis, UE indicates that when bolted connections are disassembled, they would have l a VT-1 inspection and a bolt torque or bolt tension test performed as required by both l code Editions. In the comparison table, UEstates, " bolted connections that are l disassembled anytime during the period are ::till subject to VT-3 inspections, which is unchangedfrom the 1992 Code. " It is not clear what examinations will be performed on disassembled bolted connections. If VT-1 examinations are not intended, you should discuss why not performing a VT-1 visual examination of the bolting, when disassembled, l provides and acceptable level ofquality and safety.

Reference to a VT-3 inspection in lieu of a VT-1 inspection was an error. Callaway Plant plans to perform a VT-1 inspection on the bolts, studs, nuts, bushings, washers, and threads in base material and flange ligaments of bolted connections that are disassembled for some other reason i than IWE.

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8. As your submittal does not provide information regarding the examination ofconcrete surfaces andpost-tensioning tendon system we believe that you plan to use the 1992 E&A ofSubsection IWL supplemented by 10 CFR 50.55afor the purpose. Please confirm.

l At this time, Callaway Plant is using the 1992 E&A of Subsection IWL supplemented by 10 CFR 50.55a and Relief Request ULNRC 3934.

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