NRC-98-0093, Provides Detailed Response to Request for Addl Info Re Relief Request Update for First 10-yr ISI NDE Program

Provides Detailed Response to Request for Addl Info Re Relief Request Update for First 10-yr ISI NDE Program

ML20249C457
Person / Time
Site:	Fermi
Issue date:	06/19/1998
From:	Gipson D DETROIT EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CON-NRC-98-0093, CON-NRC-98-93 NUDOCS 9806300031
Download: ML20249C457 (60)

Text

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i Douglas R. Gipson Senior Vice President, Nuclear Generation Fermi 2 6400 North Dixie llwy, Newport, Michipn 48160 Tel: 313.5%5201 Fax:3115M.4 l~2 June 19,1998 l

NRC-98-0093 -

Detroit Edison U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington D C 20555-0001 i

Reference:

1)

Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43 i

2)

Detroit Edison Letter to the NRC, " Relief Request Update for the First Ten-Year Interval Inservice Inspection (ISI)

Nondestructive Examination (NDE) Program", NRC-98-0060, i

Dated April 16,1998 I

3)

NRC Letter to Detroit Edison," Request for Additional Information Regarding the Proposed Requests for Relief for the first 10-Year Interval Inservice Inspection (ISI)

Nondestructive Examination (NDE) Program at Fermi 2 (TAC No. MA1570", dated May 28,1988

Subject:

Response to Request for Additional Information - Relief Request

- Update for the First Ten-Year ISI NDE Procram Requests for relief from the American Society of Mechanical Engineers (ASME)

Code,Section XI requirements were submitted to the NRC for the First Ten-Year L

Interval, Inservice Inspection (ISI) Nondestructive Examination (NDE) Program in

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Reference 2. In Reference 3, the NRC staffindicated that an initial review of b,"

Reference 2 had been performed, and additional information was required to complete

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., g the review of Reference 2. The NRC requested that the specific paragraph of the

4 Regulations (10CFR50.55a) under which the request was submitted, along with supportingjustification be provided. The NRC also requested information pursuant to 0

l the augmented reactor vessel inspection of 10CFR50.55a(g)(6)(ii)(A)(2).

, of this letter provides the detailed response to the Request for Additional Information (RAI) by Detroit Edison. Also, included are the updated relief requests.

e Pursuant to 10CFR50.55a(a)(3)(i), and 10CFR50.55a(a)(3)(ii) as indicated in each request for relief. Detroit Edison is requesting approval of the proposed alternatives.

Fermi Nuclear h,wer Plant personnel have identified issues during the performance of inservice inspection where alternatives to ASME Section XI 1980 including the Winter 1981 Addenda are believed to be appropriate. The Relief Requests also A DTE Energy Company

USNRC NRC-98-0093 Page 2 describe specific conditions which necessitate proposal of alternatives. Detroit Edison will incorporate these Relief Requests into the ISI NDE Program upon receipt of your approval.

Pursuant to 10CFR50.55a(g)(6)(ii)(A)(5) Fermi has also proposed an alternative to the augmented reactor vessel inspection for circumferential weld 1-313 as detailed in RAI Response No. 2.

If you have any questions or requests for additional information, please contact Mr.

Norman K. Peterson at (734) 586-4258.

Sincerely, MM-h Enclosures cc:

B. L. Burgess G. A. Harris A. J. Kugler M. T. Anderson (INEEL)

Regional Administrator, Region 3 Supervis r, Electric Operators, Michigan Public Service Commission

.c NRC-98-0093 L

Page1 l

Detroit Edison reviewed Reference 3, and summarized the items where additional information was requested. The responses (i.e., Enclosure 1) were prepared, and the relief requests (i.e., Enclosure 2) revised when appropriate. These responses were discussed with NRC representatives via telecon on June 3,1998.

Issue 1:

)

To ensure that the requests for relief are evaluated in accordance with the appropriate criteria, each request should be reviewed to determine if the appropriate paragraph of the regulations has been cited and the adequate regulatory basis supported.

Specifically in question are RR-Al, RR-A18, RR-A22 and RR-A23.

Response

The text of the relief requests did not specifically cite which subparagraph of

.10CFR50.55a applies.' The transmittal letter NRC-98-060 referenced 10CFR50.55a(a)(3) but again not the specific subparagraph. The guidance contained in NUREG-1482 regarding acceptable relief request format for IST Programs does not discuss this and previous requests for relief did not cite the rule section. In reality both rules 1 and 2 could apply to some of these relief requests. While alternatives (technical basis and/or examination) are always picposed and are intended to be the regidatory basis, there are also hardships or difficulties that would be associated with the strict Code required examination or available alternatives. Since it is not always clear which subparagraph is the regulatory basis, all relief requests will incorporate reference to the applicable basis paragraph.

Examination difficulties are discussed to support the need for each proposed alternative.

The possible regulatory bases are summarized as follows:

1) 10CFR50.55a(a)(3)(i) - The proposed alternatives would provide an acceptable level of quality and safety. This is interpreted to mean essentially equivalent to the level of quality and safety that would be achieved by the original examination.

2) 10CFR50.55a(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 or safety.

3) 10CFR 50.55a(g)(6)(ii)(A)(5)- Licensees that are unable to completely satisfy the requirements for the augmented reactor vessel shell Cd examination shall submit information to the Commission to support the L determination and shall propose an alternative.

NRC-98-0093 Page 2 RR-Al Pressure Retaining Reactor Pressure Vessel Shell Welds 10CFR50.55a(a)(3)(i) applies to examination of weld 1-313. The BWR Owners Group has prepared BWR VIP-05 that proposes to negate the need for examination requirements of circumferential shell welds entirely. As noted in RR-A1, the NRC has granted deferral for the augmented exam to four BWR plants (Brunswick-2, Hope Creek, Peach Bottom-3 and Perry) for two cycles or 40 months based on the technicaljustification provided in BWR VIP-05. The Fermi alternative for the ASME Code exam performance is partial examination for weld 1-313 because of a vessel geometry limitation. This exam was completed during the first period of the first inspection interval (RF-02) with re-inspection scheduled for the first period of L

the second inspection interval unless the BWR VIP-05 alternative is accepted by the NRC. This re-inspection is planned for RF-08, which is also two operating cycles, the same as for plants receiving the deferral. Any improvements in technobgy that u

. could increase coverage would be evaluated for application at that time and would I

have the added benefit of automated baseline data for comparison. Supporting the j;

. need for an attemative, is the exam difficulties caused by weld geometry. New.

tooling such as an ID scanner would need to be developed to augment the OD coverage and only a marginal increase would be probable because ofinternal limitations caused by the 20 jet-pump assemblies. The potential for damage of internals or fuel caused by a drop accident of the ID scanner was also considered in evaluating the slight increase in coverage attainable by the ID exam. The proposed l

exam provides adequate coverage of the ID surface where flaws would be most l

likely to originate. Based on the coverage achievable, physical limitations, current i

l technology, and the low empirical probability of reactor vessel weld failure, Detroit Edison considers the proposed alternative examination to provide an acceptable level of quality and safety.

n 10CFR50.55a(a)(3)(i) applies to examination of weld 13-308. The RPV shell to flange weld exam is limited due to vessel flange configuration. The Code proposed alternative exam of ASME Section V, Article 4, T441.5.1 (Longitudinal exam from the flange) is scheduled for RF-06 but this exam is also limited because of the RPV stud holes. Even with the Code alternative it is not possible to obtain full volume coverage even when scanning is performed from both sides of the weld for 360 degrees. As shown in the RR-Al attachment, the proposed alternative exam l

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provides significant coverage of the ID surface where flaws would be most likely to originate. A significant portion of full weld volume is also covered by the longitudinal exam from the flange surface. Based on the coverage achievable, physical limitations, current technology, and the low empirical probability of reactor vessel weld failure, Detroit Edison considers the proposed alternative exammation to 3

provide an acceptable level of quality and safety.

10CFR50.55a(a)(3)(i) applies to examination of welds 1-319A, C, E and G. The four listed top head weld exams are limited due to placement of the lifting lugs. The l

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NRC-98-0093 i

Page 3 l

critical area at the head inside surface is covered by the ultrasonic exam and the areas of highest stress on the outside surface (lifting lug attachments) receive a surface examination. Therefore, the alternative of partial examination yields similar results to a full examination. Based on the coverage achievable, physical limitations, current technology, and the low empirical probability of reactor vessel weld failure, Detroit Edison considers the proposed alternative examination to provide an hcceptable level of quality and safety.

10CFR50.55a(a)(3)(i) applies to the RPV bottom head welds made by CRD penetrations. The propcsed alternative is a combination of outage pressure testing and monitoring of drywell leakage as supplemented by the reasonable assurance of structural integrity as described in the response to issue 3. These welds are impractical to examine with current technology. Based on the leakage inspections, monitoring performed, physical limitations, low empirical probability of reactor vessel weld failure, and reasonable assurance of structural integrity, Detroit Edison j

considers the proposed alternative to provide an acceptable level of quality and safety.

RR-A18 Alternative Requirements for Qualification of VT Examination l

Personnel This relief request invokes the use of ASME Code Case N-546. Since Code Cases are ASME approved alternatives, Fermi considers paragraph 10CFR50.55a(a)(3)(i) to be the regulatory reference basis. The Code Case is ASME approved indicating the ASME Code Committee members reached a consensus that the alternative will provide essentially equivalent results to the requirements ofIWA-2300. Detroit Edison agrees with the Code Committee that use of the alternative described in this Code Case will provide an acceptable level of quality and safety.

RR-A22 Alternative Examination of ASME Class 2 Integral Attachment Welds The conservative scope of the Fermi program along with the proposed alternative examinations exceed current ASME Code requirements and assures that a high level of quality and safety is maintained, therefore 10CFR50.55a(a)(3)(i) is applicable.

l This relief request also describes difficulties that would be encountered if disassembly of clamps was performed. Based on the coverage achievable, physical limitations, current Code requirements, Fermi program scope, and low empirical l

probability of weld failure, Detroit Edison considers the proposed alternative examination to provide an acceptable level of quality and safety.

RR-A23 Alternative Examination of ASME Class 1 Pressure Retaining Piping Welds This relief request proposes the alternative of partial examination. The alternative is technically supported by comparison of the Fermi ISI Program to ASME Code f

requirements. As detailed in the relief request, the attemative assures that a high I

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f NRC-98-0093 Page 4 r

l level ofquality and safety is maintained, therefore paragraph 10CFR50.55a(a)(3)(i) is the regulatory reference basis. The relief requests also note difficulties associated l

with trying to increase coverage. Based on the coverage achievable, physical

- limitations, and comparison of Code requirements to the Fermi program, Detroit Edison considers the proposed alternative examination to provide an acceptable level of quality and safety.

Issue 2:

A) Licensees unable to completely satisfy the requirements for the L

augmented reactor vessel examinations for Category B-A, Bl.10 welds shall aubmit information to the Commission to support the detennination i

and shall propose an ahernative pursuant to 10CFR50.55a(g)(6)(ii)(A)(5).

I Provide this for the Bl.1I weld listed in RR-Al (weld 1-313).

B) Provide a list of all Bl 11 and Bl.12 welds that have been inspected and the coverage achieved for each of those welds.

- Response:

l-A. The BWR VIP Owners Group has prepared BWR VIP-05 which provides a technical basis to negate the need for examination requirements of circumferential shell. welds entirely. The NRC has granted deferral of the augmented exams to four BWR plants (Brunswick-2, Hope Creek, Peach Bottom-3 and Perry) for up to 40 months based on the technical basis for

. no examination, while the NRC reviews BWR VIP-05. Detroit Edison's proposed alternative of partial examination of weld 1-313, using the available automated technology is more conservative than deferral because the most susceptible areas for this beltline weld can be examined now. In addition to the one limited weld examination, the three other Bl.11 circumferential RPV shell welds are scheduled for examination during RF-06. Those welds are expected to be essentially 100% complete (greater than 90%) per 10CFR50.55a(g)(6)(ii)(A)(2). To date, six of fourteen longitudinal seam welds have been examined as required in i

10CFR50.55a(g)(6)(ii)(A)(2), using the GE GERIS System and the OD scanner. The remaining exams are scheduled for RF-06 and are expected j

to be essentially 100% complete. This exam was completed during the l

first period of the first inspection interval (RF-02) with re-inspection planned for the first period of the second inspection interval. This inspection is planned for RF-08, which would be two operating cycles, the same as for those plants with augmented exam deferrals. Any improvements in technology which could increase coverage would be evaluated for application at that time, with the added benefit of having l

some automated baseline data for comparison purposes.

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c NRC-98-0093 Page 5 The above discussion is intended to provide the alternative pursuant to 10CFR50.55a(g)(6)(ii)(A)(5).

B) See Enclosure 1, Attachment 1, for Augmented Vessel Weld Exam List Issue 3:

For the totally inaccessible welds listed in Relief Request RR-Al, provide a discussion of how reasonable assurance of the structural integrity will be maintained.

Response

There are several factors which provide reasonable assurance of structural integrity for the inaccessible bottom head welds. The welds received volumetric and surface NDE to verify that no deleterious material or processing defects were present at the time of fabrication. The location of the welds is at the bottom of the reactor vessel, below the withdrawn control rod blades. There is more than 170 inches of water from the bottom of the active fuel height to the weld location. This physical arrangement reduces the neutron fluence and the coincident material degrading impacts significantly, when compared to RPV beltline welds. The same CRD penetrations that prevent the examination of the welds would also serve to prevent propagation of a large defect by providing a crack arrest point. In addition to the above, monitoring of unidentified drys. ell leakage per Fermi Technical Specificatt a and visual examination for leakage following refueling outages serves to verify coninued structural integrity.

Issue 4:

For Relief Requests RR-A16 and RR-A17 referencing Code Cases N-416-1 and N-498-1 provide an acceptable regulatory basis for the staff to authorize an alternative l

examination or hardship.

Response

RR-A16 Alternative Pressure Test Requirements for Repairs and Replacements This relief request invokes the use of ASME Code Case N-416-1. Since Code Cases are ASME approved alternatives, Fermi considers paragraph 10CFR50.55a(a)(3)(i) to be the regulatory reference basis. The specific situations or plant conditions for its use are not restricted by the Code Case; however, this includes ALARA reasons, component isolation difficulties, and reducing safety system unavailability time. The Code Case is ASME approved indicating ASME Code Committee consensus that the alternative will provide essentially equivalent results, i.e., the reduction of test l

pressure to nominal operating pressure will not adversely affect test results.

Performance of the test at nominal operating pressure will also reduce the chance of over-pressurizing other components. Detroit Edison agrees with the Code Committee

• 3 NRC-98-0093 Page 6 that use of the alternative described in this Code Case will provide an acceptable level of quality and safety.

As noted in the response to Issue 1, Detroit Edison will clarify the regulatory basis for relief. This relief request incorporates reference to the specific paragraph of 10CFR50.55a.

RR-A17 Alternative Rules for 10-Year Hydrostatic Testing This relief request invokes the use of ASME Code Case N-498-1. Since Code Cases are ASME approved alternatives, Fermi considers paragraph 10CFR50.55a(a)(3)(i) to be the basis. The specific test configurations and test times identified in the Code

. Case are equivalent to the ASME Section XI requirements. Set up for the 10-year hydrostatic test would be extensive and incur unnecessary dose and equipment out of service time. Industry experience has shown that leakage is easily identified at nominal operating pressure. The Code Case is ASME approved indicating ASME Code Committee members reached a consensus that the alternative will provide essentially equivalent results, i.e., the reduction of test pressure to nominal operating pressure will not adversely affect the test intent or results. Detroit Edison agrees with the Code Committee that use of the alternative described in this Code Case will provide an acceptable level of quality and safety.

As noted in the response to Issue 1, Detroit Edison will clarify the regulatory basis for relief. This relief request incorporates reference to the specific paragraph of 10CFR50.55a.

l Issue 5:

l For Relief Request RR-A20, identify the item numbers for which reliefis requested.

l

Response

This relief request deals with ASME Class 2 piping integral attachments. The applicable Item Number of Category C-C is C3.20.

The relief request incorporates reference to this item number.

. Issue 6:

A) For Relief Requests RR-A21 and RR-A22 cost cannot be considered a burden and the burden associated with removal of clamps must be justified (provide radiation exposure information).

B) For RR-A21 do any of the subject attachment welds require volumetric examinations?

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. NRC-98-0093 Page 7 C) Provide an estimate of coverage for welds PSFW-E41-3172-625A-625D not yet completed.

1

Response

A. As discussed in the response to Issue 1, the regulatory basis is the attemative exam (partial surface exam supplemented by visual examination). Technical justification for the adequacy of the alternative is further substantiated by changes in the ASME Code. The relief request identifies the time burdens associated with engineering resource impacts, clamp removal, location restoration, which would represent a burden to existing resources. Identification of these burdens are provided only in support of the need for an alternative. The engineering impacts mentioned are incurred in diverting limited engineering resources away from other tasks.

Radiation exposure for a best case location assuming a conservative effective

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(averaged) dose rate of 5mr/hr and a minimum of 16 man-hours to remove and j

reinstall the clamp assembly and inspect the location would result in at least 80mr additional exposure per location (at least 2.3R total accumulated dose).

Note that this assumption uses an effective averaged dose rate, and actual dose on -

a pipe and is often much higher. Removal of the clamps could actually increase the possibility of damaging other components such as nozzles and penetrations due to additional line stress. Additionally, the time for disassembly and reassembly does not assume mechanical difficulties such as temporary line support, seized bolts, and removal and reinstallation of welded lug retainers from the clamps, that will greatly increase the time and dose impacts.

B. Volumetric examination is not required for any of the subject attachment welds.

Volumetric examination is only applicable to skirt type supports where access is limited to one side of the weld.

C. These lugs are on the HPCI steam supply line which is presently insulated. A conservative estimate of coverage would be at least 80% per lug.

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NRC-98-0093 Page 8, Enclosure 1 Augmented Reactor Vessel Examinations Category Weld Percentage Limitation Alternate

/ Item Identification Complete Description Examination B-NBl.11 1-313

~54%

Thickness transition Partial Exam between shell courses Recommended NRC Relief Required B-NB l.11 4-308A RF-06 Stabilizer Brackets None required

>90% coverage expected B-A/Bl.11 4-308B RF-06 None None required

>90% coverage expected B-A/Bl.11 9-307 RF-06 RPV Nozzles Supplemental manual exam required >90%

coverage expected B-NBl.12 1-308A

~92%

Stabilizer Bracket, None required Inst. Nozzle, & RPV

>90% coverage flange achieved B-NB l.12 1-308B

~92%

Stabilizer Bracket, &

None required RPV flange

>90% coverage achieved B-NBl.12 1-308C RF-06 Stabilizer Bracket, None required Inst. Nozzle, & RPV

>90% coverage flange expected B-A/Bl.12 1-308D RF-06 Stabilizer Bracket, &

None required RPV flange

>90% coverage expected B-A/B l.12 2-308A

~100%

None None required

>90% coverage ach'eved B-A/Bl.12 2-308B RF-06 None None requi:ed

>90% coverage expected B-A/B 1.12 2-308C RF-06 None None required

>90% coverage expected B-A/Bl.12 15-308A RF-06 None None required

>90% coverage

NRC-98-0093 Page 9, Enclosure 1 Augmented Reactor Vessel Examinations Category Weld Percentage Limitation Alternate l

/ Item Identification Complete Description Examination B-A/Bl.12 15-308B RF-06 None None required I

>90% coverage expected B-A/B l.12 15-308C

~100%

None None required

>90% coverage l

achieved B-A/Bl.12 15-308D RF-06 None None required

>90% coverage expected B-A/Bl.12 2-307A

~96%

RPV nozzles None required

>90% coverage achieved B-A/Bl.12 2-307B RF-06 RPV nozzles None required

>90% coverage expected B-A/Bl.12 2-307C RF-06 RPV nozzles None required

>90% coverage expected I

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ENCLOSURE 2 l

FERMI 2 NRC DOCKET NO. 50-341 NRC LICENSE NO. NPF-43 RELIEF REQUESTS RR-Al AND RR-A16 TO RR-A24 l

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l RELIEF REQUEST RR-Al REVISION 1 8 PAGES d

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RELIEF REQUEST RR-Al REVISION 1 COMPONENT FUNCTION / DESCRIPTION:

Pressure Retaining Reactor Pressure Vessel (RPV) Shell Welds (See Table 1)

SYSTEM:

Reactor (B11)

ASME CODE CLASS:

Class 1 ASME SECTION XI REQUIREMENTS:

Subsection IWB, Table IWB 2500-1, Examination Category B-A, Item No.'s B1.10 through Bl.40, require volumetric examination of RPV weld and base material regions described in figures IWB-2500-1 through 2500-3 for pressure retaining welds in the reactor pressure vessel each inspection interval.

BASIS FOR RELIEF:

Pursuant to 10CFR50.55a(a)(3)(i) Detroit Edison is requesting relief from ASME Section XI requirements to examine essentially 100% of accessible Category B-A weld lengths and is proposing attematives that provide an acceptable level of quality and safety.

Pursuant to 10CFR50.55a(a)(3)(ii) Detroit Edison is requesting relief from ASME Section XI requirements to ultrasonically examine inaccessible Category B-A weld lengths and is proposing alternatives that provide reasonable assurance of structural integrity.

Revision 0 of relief requests RR-Al and RR-A2 documented limitations based on both the installed ultrasonic examination system, which used pole tracks for scanning, and part geometry. During RF-02 Femii implemented the use of an automated examination system that uses a magnetic wheel scanning device which maximizes coverage to the extent possible using current technology. Limitations to automated scanning of RPV shell welds due to the examination system have been eliminated. Current limitations are based only on RPV configuration or interference from other components as described in t;.e "Altematives" section below.

I Reactor Vessel Ultrasonic Examination techniques meet the requirements of ASME j

Section XI; ASME Section V, Article 4; and Regulatory Guide 1.150. Detroit Edison believes that the attemative examinations proposed satisfy the intent of the ASME Code within the limits of accessibility for examination inherent to the BWR design. Table 1 i

identifies the welds with limitations encountered or expected and the cause of the limitation (see also attached figures). Manual examinations are performed where determined by the responsible NDE Level III as appropriate to increase automated exam Page i of 8

l coverage. The extent of examination will be reported in accordance with ASME Section l

V.

ALTERNATIVES:

i Weld 1-313 l

This circumferential shell weld is at the lower shell course to lower intermediate shell l

course. This limitation occurs because the transducer package cannot maintain contact in the area of the shell thickness transition (see Figure 3).

l The stress level of this circumferential weld is approximately % of the longitudinal shell welds. BWR VIP-05 provides a strong technical argument that circumferential welds should not be included in the exam population. The NRC has granted deferral for the augmented exam to four BWR plants (Brunswick-2, Hope Creek, Peach Bottom-3, and Perry) for two cycles or 40 months based on the technicaljustification provided in BWR j

VIP-05, while the NRC completes their review.

I Coverage of all critical longitudinal welds including those in the RPV beltline that intersect with weld 1-313 will be greater than 90% of the composite weld length.

The Fermi alternative for the ASME Code exam performance is partial examination for weld 1-313 because of a vessel geometry limitation. This exam was completed during the first period of the first inspection interval (RF-02), with reinspection scheduled for the j

first period of the second inspection interval, unless the BWR VIP-05 alternative is accepted by the NRC. This reinspection is plaimed for RF-08, which is also two

{

operating cycles, the same as for plants receiving the deferral. Any improvements in technology that could increase coverage would be evaluated for application at that time i

and would have the added benefit of automated baseline data for comparison.

i Supporting the need for an alternative,is the exam difficulties caused by weld geometry.

New tooling such as an ID scanner would need to be developed to augment the OD coverage and only a marginal increase would be probable because ofinternal limitations caused by the 20 jet-pump assemblies. The potential f ar damage ofinternals or fuel caused by a drop accident of the ID scanner was also considered in evaluating the slight increase in coverage attainable by the ID exam.

The proposed alternative of partial nondestructive examination provides adequate coverage of the ID surface and inner volume where flaws would be mos! likely to originate. Based on the technicaljustification provided in BWR VIP-05. coverage i

achievable using current automated technology, physical limitations, and the low empirical probability of reactor vessel weld failure, Detroit Edison considers the proposed L

alternative examination to provide an acceptable level of quality and safety.

Welds 1-319A,1-319C,1-319E, & 1-319G The four listed top head weld exams are limited because of the four lifting lug positions.

The Fermi proposed alternative for the ASME Code exam performance is partial Page 2 of 8 i

examination for these welds because of this physical limitation. The partial ultrasonic examination covers the most critical area at inside surface of the head, and the areas of highest stress on the outside surface (lifting lug attachment welds) receive a surface examination per Category B-H. The attemative of partial examination combined with the surface exam yields similar results to a full examination.

Because of the physical limitations, the extent of coverage achies able by the partial ultrasonic examination, increased assurance of structural integrity by the surface examination of the interfering lug / welds, and the low empirical probability of reactor vessel weld failure, Detroit Edison considers the proposed alternative examination to provide an acceptable level of quality and safety.

Inaccessible Bottom Head Welds The access restrictions caused by the CRD penetrations do not allow for meaningful ultrasonic examination of these welds with current technology. For the inaccessible RPV bottom head welds, the proposed attematives include a combination ASME Section XI Code required leakage inspections and monitoring of drywell leakage during operation.

Reasonable assurance of structural integrity is maintained because the welds received volumetric and surface NDE to verify that no deleterious material or processing defects were present at the time of fabrication. The welds are physically located at the bottom of the reactor vessel, below the withdrawn control rod blades. There is also more than 170 inches of water from the bottom of the active fuel height to the weld location. This physical arrangement reduces the neutron fluence and the coincident material degrading impacts significantly, when compared to RPV beltline welds that are inspectable. The same CRD penetrations that prevent the examination of the welds would also serve to prevent rapid propagation of a large defect by providing a crack arrest point.

Because of the visual inspections (VT-2 ) and leakage monitoring performed, physical limitations, reasonable assurance of structural integrity for these welds, and the low empirical probability of reactor vessel weld failure, Detroit Edison considers the proposed alternative to provide an acceptable level of quality and safety Weld 13-308

. The RPV shell to flange weld exam is limited due to vessel flange configuration. The Code proposed alternative exam of ASME Section V, Article 4, T441.5.1 (Longitudinal exam from the flange) is scheduled for RF-06 but this exam is limited because of the RPV stud holes. Even with this Code allowed alternative, it is not possible to obtain full volume coverage even when scanning is performed from both sides of the weld for 360 degrees.

The Fermi proposed alternative is a partial exam from the shell side combined with the longitudinal wave exam from the flange surface. As shown in Figure 3, the proposed alternative partial exam performed from the shell side provides significant coverage of the ID surface where flaws would be most likely to originate. A significant portion of Page 3 of 8 l

full weld volume is also covered by the longitudinal exam from the flange surface. Based on physical limitations, the coverage achievable by the attemative examinations, and the low empirical probability of reactor vessel weld failure, Detroit Edison considers the proposed alternative examination to provide an acceptable level of quality and safety APPLICAllLE TIME PERIOD:

Reliefis requested for the first 10-year inspection interval.

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l RR-Al Table 1 i

LIMITED EXAMINATIONS Category Weld Percentage Limitation Description

/ Item Identification Complete B A/Bl.11 1-313

~54%

Thickness transition between shell Vessel Cire.

courses Weld B-NB l.21 5-306 Inaccessible Bottom head CRD Penetrations and Head Circ. Weld Skirt Attachment Weld (Dollar Plate)

B-NB l.22 1-319A

~80%

Top Head Lif ting Lugs l

Hd. Merid. Weld i

B-NB l.22 1-319C

~80%

Top Head Lifting Lugs Hd. Merid. Weld f

B-A/B l.22 1-319E

~80%

Top Head Lifting Lugs lid. Merid. Weld B-A/ B l.22 1-319G

~80%

Top Head Lilling Lugs l

Hd. Merid. Weld B A/Bl.22 2-306A Inaccessible Bottom head CRD Penetrations and Hd. Merid. Weld Skirt Attachment Weld B-A/B l.22 2-306B Inaccessible Bottom head CRD Penetrations and lid. Merid. Weld Skirt Attachment Weld B-A/B l.22 2-306C Inaccessible Bottom head CRD Penetrations and l

Hd Merid. Weld Skirt Attachment Weld l

B-A/B l.22 2-306D inaccessible Bottom head CRD Penetrations and j

Hd. Merid. Weld Skirt Attachment Weld i

B-A/B l.22 2-306E Inaccessible Bottom head CRD Penetrations and l

lid. Merid. Weld Skirt Attachment Weld B-NB l.22 2-306F Inaccessible Bottom head CRD Penetrations and Hd. Merid. Weld Skirt Attachment Weld B-NB l.22 2-306G Inaccessible Bottom head CRD Penetrations and Ild. Merid. Weld Skirt Attachment Weld B-A/B l.30 13-308

~60%

RPV Flange Configuration (coverage Shell to Flange augmented by scan from flange seal surface) i i

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NRC-98-0093 Page 3

[

l RELIEF REQUEST RR-A16 2 PAGES PLUS CASE N-416-1 i

1 i

s

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RELIEF REQUFST l

RR-A16 COMPONENT FUNCTION / DESCRIPTION:

Class 1,2, & 3 Pressure Retaining Piping & Components SYSTEM:

All systems included in the ISI NDE Program ASME CODE CLASS:

Class 1,2, and 3 ASME SECTION XI REQUIREMENTS:

ASME Section XI,1980 Edition including the Winter 1981 Addenda, Subsection IWA-4000 requires hydrostatic pressure tests for welded repairs and replacements unless specifically exempted in IWA-4400.

H ASIS FOR REL2IEF:

Pursuant to 10CFR50.55a(a)(3)(i), Detroit Edison is requesting relief from ASME Section XI requirements to perform hydrostatic tests following repairs and replacements.

Detroit Edison is proposing to implement the alternative of ASME Code Case N-416-1 (copy attached). This Code Case is ASME approved indicating Code Committee consensus that the alternative will provide essentially equivalent results, i.e., the reduction of test pressure to nominal operating pressure will not adversely affect test results. Performance of the test at nominal operating pressure will also reduce system unavailability and the chance of over-pressurizing other components. Detroit Edison agrees with the Code Committee that use of the altemative described in this Code Case will provide an acceptable level of quality and safety.

This Code Case has also been approved for use at other nuclear utilities (e.g., Perry).

This Code Case was reviewed by the NRC as indicated in Draft Guide DG-1050 issued February 1997 and is to be approved in next revision of Regulatory Guide 1.147.

ALTERNATIVE EXAMINATION:

Code Case N-416-1 (attached) allows for the performance of test at nominal operating pressure in lieu of a hydrostatic pressure test required by IWA-4000 providing the following requirements are met.

(a) NDE shall be performed in accordance with the methods and acceptance I

criteria of the applicable Subsection of the 1992 Edition of Section III.

(b) Prior to or immediately upon return to service, a visual examination (VT-2) shall be performed in conjunction with a system leakage test, using the 1992 Edition of Section XI, in accordance with paragraph IWA-5000, at nominal operating pressure and temperature.

Page 1 of 2

J (e) Use of the Code Case shall be documented on the NIS-2 form.

(d) In addition, a supplementary requirement to perform additional surface NDE on the root-pass layer of butt and socket welds where the surface examination method is selected for Class 3 components is included as specified in DG-1050.

APPLICABLE TIME PERIOD:

Reliefis requested for the remainder of the first 10-year interval or until Code Case N-416-1 is incorporated into Regulatory Guide 1.147.

Fermi will use the Code Case with the additional stipulation of(d) above (DG-1050) until the Code Case is approved by the NRC and incorporated into Regulatory Guide 1.147.-

At that time, this relief request will expire and Fermi will use the Code Case as approved by the NRC.

l Page 2 of 2 4

1 CASES OF ASME DOILER AND PRES $tmE YE55EL COSE f-A9 proval Date: February 15.1994

~

See Numene Indes for es$euen and any reaffirmarlen deres.

Case N4161 p!e--M items by welding, a system leakage test may Altensative Pressure Test Requirement for Welded be used provided the following requimments are met.

Repairs or InstaBation of Replacement Items.by E

(a) NDE shall be I rformed in accontance with the Walding, Class 1,2 and 3 methods and acceptarice criteria of the applicable Sub.

Section XI. Division 1 section of the 1992 Edition of Section III.

(b) Prior to ori==^tely upon rerum to servi:c, a vuual ernmination (VT-2) shall be performed is con-Inquiry: What altemative pressure test may be per-junction with a system leakage test. using the 1992 Edi-formed in lieu of the hydrostatic pressure test required tion of Section XI. in acecniance with para. !WA.5000, by para. IWA 4000 for welded repairs or installauon of replacement items by welding?

at nominal operating pressure and temperature.

(c) Use of this Case shall be documented on an NIS.

2 Form.

Reply:It is the opinion of the Comminee that in lieu If the previous version of this case were used to defer of performing the hydrostade pressure test required by a Class 2 hydrostatic test, the deferred test may be clim.

para. IWA-4000 for welded repairs orinsullation of re-insted when the requirements of this revision are met.

6

.I9 i

l SUPP 3 - N:

NRC-98-0093 Page 4 l

1 1

l l

l l

l RELIEF REQUEST RR-A17 3 PAGES PLUS CASE N-498-1 l

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l l

I

RELIEF REQUEST RR-A17 COMPONENT FUNCTION / DESCRIPTION:

l Class 1,2, & 3 Pressure Retaining Piping & Components SYSTEM:

All systems included in the ISI NDE Program ASME CODE CLASS:

Class 1,2, and 3 ASME SECTION XI REOlif REMENTS:

ASME Section XI,1980 Edition including the Winter 1981 Addenda, Tables IWX-2500-i 1 for Examination Categories B-P, C-II, D-A, D-B, and D-C require performance of a hydrostatic pressure test once during each ten-year inspection interval.

l BASIS FOR RELIEF:

Pursuant to 10CFR50.55a(a)(3)(i) Detroit Edison is requesting relief from ASME Section XI requirements to perform the 10-year hydrostatic tests listed above. Detroit Edison is proposing to implement the alternative of ASME Code Case N-498-1 (attached). The specific test configurations and test times identified in the Code Case are equivalent to the ASME Section XI requirements. Set up for the 10-year hydrostatic test would be extensive and incur unnecessary dose and equipment out of service time. Industry J

experience has shown that leakage is easily identified at nominal operating pressure. The l

Code Case is ASME approved indicating ASME Code Committee members reached a consensus that the alternative will provide essentially equivalent results, i.e., the reduction of test pressure to nominal operating pressure will not adversely affect the test intent or results. Detroit Edison agrees with the Code Committee that use of the altemative described in this Code Case will provide an acceptable level of quality and safety.

l This Code Case has also been approved for use at other nuclear utilities (e.g., Perry).

This Code Case was reviewed by the NRC as indicated in Draft Guide DG-1050 issued February 1997 and is to be approved in the next revision of Regulatory Guide 1.147.

ALTERNATIVE EXAMINATION:

Code Case N-498-1 provides the following alternative requirements that allow VT-2 examinations to be performed at system / component nominal operating pressure in lieu of hydrostatic test pressures.

(a) Category B-P (1) A system leakage test (IWB-5221) shall be conducted at or near the end of each inspection interval, prior to reactor startup.

l t

Page1oi3

(2) The boundary subject to test pressurization during the system leakage test shall extend to all Class I pressure retaining components within the system boundary.

(3) Prior to performing the VT-2 examination, the system shall be pressurized to nominal operating pressure for at least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for insulated systems and 10 minutes for noninsulated systems. The system shall be maintained at nominal operating pressure during perfonnance of the VT-2 examination.

(4) Test temperatures and pressures shall not exceed limiting conditions for the hydrostatic test curve as contained in the plant Technical Specifications.

(5) The VT-2 visual examination shall include all components within the boundary identified in (a)(2) above.

(b) Category C-II (1) A system pressure test shall be conducted at or near the end of each inspection interval or during the same inspection period of each inspection interval ofInspection program B.

(2) The boundary subject to test pressurization during the system pressure test shall extend to all Class 2 components included in those portions of systems required to operate or support the safety system function up to and including the first normally closed valve, including a safety or relief valve, or valve capable of automatic closure when the safety function is required.

(3) Prior to performing the VT-2 visual examination, the system shall be pressurized to nominal operating pressure for a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for insulated systems and 10 minutes for noninsulated systems. The system shall be maintained at nominal operating pressure during performance for the VT-2 visual examination.

(4) The VT-2 visual examination shall include all components within the boundary identified in (b)(2) above.

(5) Test instrumentation requirements ofIWA-5260 are not applicable, j

i (c) Categories D-A, D-B, & D-C i

(1) A system pressure test shall be conducted at or near the end of each inspection interval or during the same inspection period of each inspection interval ofInspection Program B.

(2) The boundary subject to test pressurization during the system pressure test shall extend to all Class 3 components included in those portions of systems required to operate or support the safety system function up to and l

including the first normally closed valve, including a safety or relief valve, l

or valve capable of automatic closure when the safety function is required.

(3) Prior to performing the VT-2 visual examination, the system shall be pressurized to nominal operating pressure for at least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for insulated systems and 10 minutes for noninsulated systems. The system shall be l

l Page 2 of 3

t-a maintained at nominal operating pres.;ure during performance of the VT-2 visual examhation.

(4) The VT-2 visual examination shall include all components within the boundary identified in (2) above.

- (5) Test instrumentation requirements ofIWA-5260 are not applicable.

I l

i APPLICABLE TIME PERIOD:

Reliefis requested for the remainder of the first 10-year interval or until Code Case N-498-1 is incorporated into Regulatory Guide 1.147.

Fermi proposes use of Code Case 498-1 as published by the ASME Committee, until it is t

approved by the NRC and incorporated into Regulatory Guide 1.147. At that time, this relief request will expire and Fermi will continue use of the Code Case as approved by the NRC.

l Page 3 of 3

l-1 CASE N-498-1

'l CASES OF ASME BOILER AND PRESStJRE VE$SEL CODE Approval Date: May 11,1994 See Numericalindex for expiration and any reemimation dates.

l l

- Case N-4981 (2) The bounda-7 subject to test pressurization Alternativ* Rules for 10-Year System Hydrostatic during the system pressure test shall extend to all Testing to. Clasa 1,2, and 3 Systems Class 2 components included in those portions of sys.

Section'XI, Division 1 tems required to operate or support the safety system function up to and including the first normally closed Inquiry: What alternative rules may be used in lieu valve, including a safety or relief valve, or valve ca-of those required by Sect on XI, Division 1, Table pable of automatic closure when the safety function i

('

egory C H, and Table IWD-2500-1, Categories D-A, (3) Prior to performing the VT-2 visual exami-IWB-25001, Category B P, Table IWC-2500-1, Cat.

is required.

D-B, and D-C, as applicable, for the 10-year system nation, the system shall be pressurized to nominal hydrostatic test? -

operating pressure for a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for in-sulated systems and 10 minutes for noninsulated sys.

tems. He system shall be maintained at nominal op-erating pressure during performance of the W 2 1

Reply:

visual arammation.

(a) It is the opinion of the Committee that as an (4) De VT-2 visual aramination shall include alternative to the 10-year system hydrostatic test re-all components within the boundary identified in 1

quired by Table IWB 2500-1, Category B P, the J.

(b)(2) above.

lowing rules shall be used.

(5) Test instrumentation requirements of IWA-(1) A system leakage test (IWB-5221) shall be 5260 are not applicabe.

l

(,L conducted at or near the end of ec:h inspection in.

(c) It is the opinion of the Committee that, as an l

terval, prior to reactor startup.

alternative to the 10-year system hydrostatic test re.

l (2) The boundary subject to te:t pressurization quired by Table IWD-2500-1, Categories D A, D B, during the system leakage test shall extend to all or D-C (D B for the 1989 Edition with the 1991 and Cass 1 pressure retaining components within the sys.

subsequent Addenda), as applicable, the following tem boundary.

rules shall be used.

(3) Prior to performing the W 2 visual exami-(1) A system pressure test shall be conducted at nation, the system shall be pressurized to nominal or near the end of each inspection interval or during operating pressure for at least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for insulated the same inspection period of each inspection inter-systems and 10 minutes for noninsulated systems.

val of Inspection Ngreiii B.

The system shall be maintained at nominal operating (2) The boundary subject to test pressurization pressure during performance of the VT 2 visual ex-during the system pressure test shall extend to all amination.

Cass 3 components included in those portions of sys-Lt (4) Test temperatures and pressures shall not tems required to operate or support the safety system l

exceed limiting conditions for the hydrostatic test function up to and including the first normally closed curve as contained in the plant Technical Specifica-valve, including a safety or relief valve, or valve ca-tions.

pable of automatic closure when the safety function (S) The W 2 visual examination shall include is required.

all components within the boundary identified in (3) Prior to performing the VT-2 visual exami-(a)(2) above, nation, the system shall be press.trized to nomina.1 (6) Test instrumentation requirements of IWA-operating pressure for at least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for insulated 5260 are not applicable.

. (b) It is the opinion of the Committee that, as an systems and 10 minutes for noninsulated systems.

l l

alternative to the 10-year system hydrostatic test re.

De system shall be maintained at nominal operating pressure during performance of the W-2 visual ex-quired by Table IWC-25001, Category C-II, the fol-amination.

lowing rules shall be used:

(4) he VT-2 visual examination shall icelude (1) A system pressure test shall be conducted at all camponents within the boundary identified in or near the end of each inspection interval or during (c)(2) above.

the same inspection period of each inspection inter-(5) Test instrumentation requirements of IWA-val of Inspection Proi,; am B.

5260 are not applicable.

849 t @eo o - e

NRC-98-0093 Page 5 l

RELIEF REQUEST RR-A18 2 PAGES PLUS CASE N-546

RELIEF REQUEST RR-A18 COMPONENT FUNCTION / DESCRIPTION:

Class 1,2, & 3 Pressure Retaining Piping & Components SYSTEM:

All systems included in the ISI NDE Program ASME CODE CLASS:

Class 1,2, and 3 ASME SECTION XI REQUIREMENTS:

ASME Section XI,1980 Edition including the Winter 1981 Addenda, Tables IWB-2500-1, IWC-2500-1 and IWD-2500-1 require the performance of a VT-2 examination during the specified pressure tests. IWA-2300 requires that personnel performing the VT-2 examinations be qualified by the owner or the owner's agent in accordance with owners qualification program having levels of competency comparable to SNT-TC-1 A as defined in ANSI N45.2.6.

HASIS FOR RELIEF:

Pursuant to 10CFR50.55a(a)(3)(i) Detroit Edison is requesting relief from ASME Section XI requirements to certify VT-2 examiners in accordance with IWA-2300. Detroit Edison is proposing to use the alternatives specified in ASME Code Case N-546 (copy attached). This will eliminate the need to qualify VT-2 examination personnel in the same manner as NDE personnel. VT-2 requires no special knowledge of technical principles, it is simply an inspection for evidence ofleakage. No special skills or technical training are required in order to observe water dripping from a component or bubbles forming on a surface wetted with a leak detection solution. Therefore, qualification in accordance with the provisions of the Code Case will not present any reduction in quality or safety. In fact, it will facilitate the qualification of those personnel most familiar with the walkdown of plant systems.

The Code Case is ASME approved indicating the ASME Code Committee members reached a consensus that the alternative provides essentially equivalent results to the requirements ofIWA-2300. Detroit Edison agrees with the Code Committee that use of the alternative described in this Code Case will provide an acceptable level of quality and safety.

ALTERNATIVE:

Code Case N-546 provides the following alternative qualification rules for personnel such as licensed and nonlicensed operators, local leak rate persormel, system engineers, and inspection and nondestructive examination personnel.

Page1 of2

4 (a) The individual must have at least 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> plant walkdown experience such as that gained by licensed and nonlicensed operators, local leak rate personnel, system engineers, and inspection and nondestructive examinat:on personnel.

(b) At least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of training on Section XI requirements and plant specific procedures for VT-2 visual examination will be completed.

(c) Vision test requirements ofIWA-2231 (1995 Edition) will be satisfied.

In addition, the following actions will ensure consistent quality in the performance of examinations.

1. Records of the training and qualifications specified in Code Case N-546 will be provided and maintained in accordance with the Fermi written practice.

2. Visual examination will be conducted in accordance with specific written procedures.

3. Visual examination procedures will provide for a documented independent review and evaluation of test results.

APPLICAllLE TIME PERIOD:

Reliefis requested for the remainder of the first 10-year interval.

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Page 2 of 2

CASE N-546" CASES OF ASME BOILER AND MtES3URE YE55Et. CODE Approval Date: August 24. 1995 See NumencelIndex for excitetson and any reathemation dates.

Case N 546 accordance with the referenced standard ti.e.. ANS1 Alternadve Requirements for Qualificatiuc of N45.2.6. ASNT SNT.TC.l A. or ASNT CF.189) pno VT.2 Examination Personnel vided the examination personnel are qualified in accord.

Section 4 Dision 1 ance wnh the following requirement.t.

(a) At least 40 his plant walkdown expenence. xuch Inquin1 What alternative to the requirernents of IWA.2300 may be used for qualification of VT-2 visual I cal leak rate personnel, system engineers, and inspec.'

examination personnel?

tion and nondestructive examination personnel.

(b) At least 4 hrs of training on Section XI require.

ments and plant specific procedures for VT.2 visual Reply 11 is the opinion of the Comrnsttee that VT.

examination.

2 visual examination personnel need not be qualified (c) Vision test requirements of IWA.232). 1995 nor certified to comparable levels of competence in Edition.

0 l

1080

NRC-98-0093 l

Page 6 RELIEF REQUEST RR-A19 2 PAGES I

0 RELIEF REQUEST RR-A19 i

COMPONENT FUNCTION / DESCRIPTION:

Insulated portions of High Pressure Coolant Injection (HPCI) turbine / exhaust lines, and associated vents and drains.

SYSTEM:

High Pressure Coolant Injection (E41)

ASME CODE CLASS:

Class 2 ASME SECTION XI REQUIREMENTS:

Section XI Code Case N-498 (Alternative Rules for 10-year Hydrostatic Pressure Testing) which is included in the Fermi Inservice Inspection Program, requires a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time afler attaining nominal operating pressure conditions for insulated systems.

BASIS FOR RELIEF:

Pursuant to 10CFR50.55a(a)(3)(ii) Detroit Edison is requesting relief from ASME Section XI requirements to maintain a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time prior to the visual examination for the pre.ssure test described in this relief request. Fermi proposes to perform the test using an alternative hold time of 20 minutes. This alternative is necessary because the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time could result in sys;em conditions outside of Technical Specification operating limits.

As part of the Emergency Core Cooling System (ECCS), the HPCI system is not required to operate during normal plant operation. However, the system is periodically tested in accordance applicable inservice testing and Technical Specification requirements. These periodic tests are conducted to verify the operability of systein components. The quarterly operability test (24.202.001) normally includes about 30 minutes of pump run time. In order to satisfy ASME Section XI hold time requirement, the test would require a HPCI pump run for greater than 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> (hold time plus exam time). Running the HPCI pump for this duration is not practical and represents an undue hardship on the facility without a compensating increase in the level of quality and safety.

Operating the HPCI pump for this amount of time ". auld subject the facility to excessive l

heat loads. Control of these heat loads would require the operation of udditional ECCS subsystems to remove heat from the suppression pool.

l Extended operation of the HPCI pump would abo challenge the Technical Specification limitation on maximum suppression pool (torus) water temperature. The Fermi Technical Specifications require the torus at erage water temperature to be maintained less than 105 F during testing which adds heat to the torus. Operating the HPCI pump for a period substantially longer than the system operability test could cause this temperature to be i

Page 1 of 2

exceeded. If the torus average water temperature exceeda 100 F, Technical Specifications require the reactor mode switch to be placed in the shutdown position.

Removal of the insulation from the subject components in order to use the ten minute hold time allowed by the Code or Code Case N-498, would be equally burdensome. The irrpacts associated with insulation removal and reinstallation include personnel radiation exposure, radwaste generation, and limited manpower resources are not justified by a compensating increase in the level of quality and safety.

Performing a HPCI system hydrostatic test per IWA 5213 (d) would also be burdensome.

A hydrostatic test would require installation of blank flanges and temporary pipe supports and gagging or removal of relief valves. System out of service time and radiation exposure incurred in carrying out a hydrostatic test would result in a hardship without a compensating increase in the level of quality and safety.

Other inspection and test activities performed that serve to verify continued system integrity include the foliowing:

Quarterly inservice testing of HPCI raises the pressure of the system to nominal operating conditions. Any leakage would migrate through the insulation over a

\\

period of time and would become evident.

Nondestructive examination of 25% or 14 of the circumferential welds on this line receive a surface examination per Section XI Tab!c IWB-2500-1, Category C-F. All of the weld selections on this line were random selections because none of the welds met the moderate or high stress criteria.

Every 18 months this line is inspected in accordance with the Fermi Leakage Reduction Program per Technical Specification 6.8.5.

ALTERNATIVE EXAMINATION:

The system pressure test described in Code Case N-498 will be conducted as required, except that a 20 minute hold time will be used in lieu of the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time requirement.

The 20 minute hold time will allow time for abnormal leaks to migrate through the insulation without challenging the Technical Specificati m limitation on maximum torus water temperature. Any evidence of abnonnal leakage will be investigated by locally removing insulation. A similar alternative for test performance was approved at another nuclear utilities (e.g., Hope Creek).

Reasonable assurance of system structural integrity is maintained through implementation of the alternative test and by the extent and frequency of other Technical Specification /ASME required system operability tests.

APPLICABLE TIME PERIOD:

Reliefis reqwsted for the first 10-year inspection interval.

Page 2 of 2

NRC-98-0093 Page 7 I

RELIEF REQUEST RR-A20 2 PAGES l

l l

4 i

l 1

l lu

1

{

RELIEF REQUEST j

RR-A20 l

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COMPONENT FUNCTION / DESCRIPTION:

Piping Integral Attachment Welds (Stiffeners) Inside The Suppression Pool (Torus) l RilR Torus Penetrations X-210A and B and Core Spray Penetration X227A and B ISI Isometric Drawings:

I 6M7213160 RIIR Test Line & Suppression Chamber Spray Header (North) 6M7213161 RHR Test Line & Suppression Chamber Spray Header (South) 6M7213145 North Core Spray Min / Low Flow By-pass & Test Line l

6M7213150 North Core Spray Min / Low Flow By-pass & Test Line SYSTEMS:

Residual Heat Removal (El 1) and Core Spray (E21)

ASME CODE CLASS:

Class 2 ASME SECTION XI REQUIREMENTS:

ASME Section XI,1980 Edition including the Winter 1981 Addenda, Subsection IWC, Table IWC-2500-1, Category C-C, Item C3.20 requires surface examination ofintegrally welded piping attachments that have a base metal design thickness of %" or greater.

l BASIS FOR RELIEF:

Pursuant to 10CFR50.55a(a)(3)(ii) Detroit Edison is requesting relief from ASME i

Section XI requirements to perform a surface examination of torus intemal piping integrally welded attachments that have a base metal design thickness of %" or greater.

The Fermi design includes torus stiffener pads and gusset plates which are welded to the system piping that penetrates the torus. Because of the base metal thickness (>3/4") these welds require a surface examination.

The interior surfaces of the torus are coated to prevent corrosion of surfaces which are exposed to the humid atmosphere. Performing a magnetic particle examination of the l

torus stiffener pads and gusset welds would require this coating to be ground off and reapplied after the examinations are complete. Grinding off the coating to allow a proper examination takes a substantial amount of time and the grinding process could result in paint chips and dust entering the torus pool. The humidity could also have a negative impact on examination performance as surface condensation would restrict particle l

movement.

The penetrations are over water surface and are not accessible from the cat walk. Gaining accessibility to the penetrations would require a suspended scaffold to be built and a catch hung to prevent debris entry into the torus pool. Craft personnel have estimated that it Page 1 of 2

would take six laborers three shifts per location to build this type of structure.

Performance of this work would not be consistent with good ALARA practices.

Both of the subject piping systems are open ended into the torus. The ASME Section XI 1989 Edition currently approved by the NRC and incorporated into 10CFR50.55a by reference and later Editions through the 1995 Edition pending NRC approval, provide exemption from examination for open ended piping beyond the last shutoff valve (IWC 1220). When Fermi completes the required program update these welds will no longer require examination.

These penetrations also have integral attachments on the torus external surface that require examination per the 1980 Edition of ASME Section XI. Examination of these external attachment welds would indicate any damage to the piping system at the penetrations that would prevent the fluid from reaching the torus.

Performance of these exams presents an undue hardship without a compensating increase in the level of quality or safety.

ALTERNATIVE EXAMINATION:

Fermi proposes to examine the extemal portion of the piping attachment, and perform remote VT-3 examination to the extent practical on the internal portion from the catwalk using binoculars. This alternative is more conservative tha current Code requirements; therefore, it provides an adequate level of quality or safety.

APPLICAHLE TIME PERIOD:

1 Reliefis requested for the first 10-year inspection interval.

i

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/

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x N/

V Typical Torus Internal Stiffener Sketch Page 2 of 2

NRC-98-0093 Page 8 RELIEF REQUEST RR-A21 4 PAGES

RELIEF REQUEST RR-A21 COMPONENT FUNCTION / DESCRIPTION:

l Piping Integral Attachment Welds (see attached Table for identification)

SYSTEMS:

Main Steam (B21) j l

Reactor Recirculation (B31)

Residual Heat Removal (El1)

Core Spray (E21).

l Feedwater (N21)

ASME CODE CLASS:

l Class 1 l

ASME SECTION XI REQUIREMENTS:

ASME Section XI,1980 Edition including the Winter 1981 Addenda, Subsection IWB, l

Table IWB-2500-1, Category B-K-1, item B10.10 requires surface examination of all integrally welded piping attachments that have a base metal design thickness of 5/8" or greater.

BASIS FOR RELIEF:

Pursuant to 10CFR50.55a(a)(3)(i) Detroit Edison is requesting relief from ASME Section I

XI requirements to perform complete (> 90% coverage) surface examination of all l

integrally welded piping attachments that have a base metal design thickness of 5/8" or greater.

The proposed altemative is partial nondestructive examination supplemented by visual examination. Technicaljustification for the adequacy of the alternative is substantiated by changes in the ASME Code.

The relief request also identifies burdens associated with engineering resource impacts, clamp removal, location restoration, which would represent a burden to existing l

resources. Identification of these burdens are provided only in support of the need for an j

alternative. The engineering impacts mentioned are incurred in diverting limited l

engineering resources away from other tasks.

The structural integrity of the piping pressure boundary including welded attachments was originally demonstrated during construction by meeting the requirements of ASME Section III. Design, fabrication, installation, inspection, and examination satisfied the appropriate Code requirements. Construction examinations used techniques similar to those used for inservice examinations (surface NDE methods). During the Fermi Preservice Inspection volumetric examinations were also performed. The construction and preservice examinations were usually completed prior to installation of the support Page1of4

members. Therefore the extent of accessit,ility is not specifically know until the first inservice examination is completed. Integral attachment locations remaining to be examined were compared to locations similar in design and any expected limitations are listed in the table.

The pressure boundary passed the required preservice hydrostatic test and all subsequent pressure tests through the fifth refueling and inspection outage (RF-05).

Complete examinations meeting the coverage requirements of ASME Code Section XI are perfonned on welds of similar configurations which utilized the same weld techniques, procedures and materials. The welds with complete examinations are spread throughout the Class I systems and subject to similar operating and environmental conditions as the partially examined welds. No service related discontinuities have been discovered on welds fully examined or those partially examined. Additionally, there is no industry history of ASME Class 1 service induced attachment weld failures. It is reasonable to expect that the unexamined por9ons are also acceptable.

The absence of significant integral attachment weld problems is further evidenced by ASME Code Case N-509 which allows a reduced sample size of only 10% of all integral attachments. This Code Case has been approved at other nuclear facilities (e.g., Duane Arnold) and was incorpomted into the 1995 Addenda of ASME Section XI. Detroit Edison has not requested to implement this Code Case, which would reduce the inspection population to approximately 10 locations, during our first inspection interval.

We are only requesting partial relief of coverage on specific locations included in the 29 locations where examinations can be performed.

The average surface coverage for the incomplete examinations completed and listed in Table 1 is 73%. To obtain complete Code coverage at each location, the component support would have to be disassembled and the pipe clamp assembly removed.

Temporary line support would have to be evaluated by engineering and installed as necessary. The additional engineering resources, time, field personnel, and radiation exposure required to attain full coverage is not consistent with the minimal risk associated with these items, as rellected by plant and industry experience as well as current Code requirements.

Radiation exposure for a best case location assuming a conservative effective (averaged) dose rate of Smr/hr and a minimum of 16 man-hours to remove and reinstall the clamp assembly and inspect the location would result in at least 80mr additional exposure per location (approximately 1.7R minimum accumulated dose). Note that this assumption uses an effective averaged dose rate, and actual dose on a pipe and is often much higher.

Removal of the clamps could actually increase the possibility of damaging other components such as nozzles and penetrations due to additional line stress. Additionally, the time for disassembly and reassembly does not assume mechanical difficulties such as temporary line support, seized bolts, and removal and reinstallation of welded lug retainers from the clamps, that will greatly increase the time and dose impacts.

Page 2 of '

ALTERNATIVE EXAMINATION:

Detroit Edison proposes that in addition to the surface examination of the exposed portion oflug welds and required base metal volume, that a supplemental visual examination to the extent practical by the examiner be performed. Additionally, leakage inspections are performed at the completion ofeach refueling outage per Category B P.

Based on the coverage achievable, physical limitations, comparison of Fermi ISI Program scope as compared to current Code requirements, and low empirical probability of weld failure, Detroit Edison considers the proposed alternative examination to provide an acceptable level of quality and safety.

APPLICABLE TIME PERIOD:

Reliefis requested for the first 10-year inspection interval.

l Page 3 of 4 i.

RR-A21 Table 1 Limited Examinations Category Weld Percentage Limitation Alternate

/ Item Identification Complete Description Examination B-K-l/B l0.10 FW PS 2-B2-70%

Clamp at spring B215353-Supplemental AAl-AA4 Expected HBI Visual B K 1/B10.10 FW-PS-2 D2 70 %

Clamp at spring B215355 Supplemental AAl-AA4 HDI Visual B-K l/B10.10 FW-RD-2 A2-68 %

Clamp at spring B315357-Supplemental All-AL4 HA2 Visual B K-l/Bl0.10 FW-RD-2-B2-68 %

Clamp at spring B315359-Supplemental All AL4 Expected 11B2 Visual B-K-1/B 10.10 SW RS-2-A2-W4-68 %

Clamp at spring B31-5357-Supplemental W7 Expected HAl Visual B-K l/B10.10 SW-RS-2-B2-68%

Clamp at spring B31-5359-Supplemental W6A W9A HB1 Visual B-K-1/B 10.10 PSFW-El 1-2298-69% per lug Clamp at rigid support Supplemental 833A-F El 1-2298-G04 Visual B-K-l/Bl0.10 PSFW El1-2299-50% per lug Clamp at spring El1-2299-Supplemer.tal 836A-F Expected G03 Visual B-K l/B10.10 PSFW El12299-50% per lug Clamp at spring El1-2299-Supplemental 781A D G01 Visual B-K l/Bl0.10 SW-El 1-2327-90% per lug Clamp at restraint ElI-Supplemental 2WD-2WJ 2327-G03 Visual B-K-1/B 10.10 SW-E21 3052-88% per lug Clamp at spring E213052-Supplemental 2WN-2WR G02 Visual B-K l/Bl0.10 PSFW-E21-3052-84% per lug Clamp at spring E21-3052-Supplemental 803 A-D G04 Visual B-K-1/B l0.10 SW E213053-86% per lug Clamp at spring E213053-Supplemental 2WN-2WR G02 Visual B-K l/B10.10 SW-E21 3052-88% per lug Clamp at spring E213052-Supplemental 2WS-2 WV Expected G09 Visual B-K-1/B10.10 SW E21-3053-69% per lug Clamp at spring E213053 Supplemental 2WS-2WV G10 Visual B-K 1/Bl0.10 SW-E21-3053-88% per lug Clamp at spring E21-3053-Supplemental 795A 795D G08 Visual B-K 1/B10.10 SW N21-2336-86% per lug Clamp Limitation Supplemental 12WC-12WH Visual B-K l/Bl0.10 SW N21-2336 66% per lug Clamp Limitation Supplemental 12WJ 12WP Visual B-K-1/B 10.10 SW-N21 2336-0% per lug Inaccessible for MT due to Supplemental 19WB-19WE lug retainers at N213537 Visual G29 l

B-K-l/B 10.10 SW-N21-2336-90% per lug Clamp at snubber Supplemental l

9WB-9WE N213536-G29 Visual B-K-1/B l 0.10 SW N21-2336-90% per lug Clamp at spring N213537 Supplemental 2WC-2WN G26 Visual Page 4 of 4

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NRC-98-0093 j

Page 9 l

RELIEF REQUEST RR-A22 4 PAGES l

RELIEF REQUEST RR-A22 COMPONENT FUNCTION / DESCRIPTION:

Piping Integral Attachment Welds (see attached Table for identification)

SYSTEMS:

Residual Heat Removal (El1)

High Pressure Coolant Injection (E41)

ASME CODE CLASS.

Class 2 l

j ASME SECTION XI REQUIREMENTS:

ASME Section XI,1980 Edition meluding the Winter 1981 Addenda, Subsection IWC, Table IWC-2500-1, Category C-C, items C3.10 and C3.20 require surface examination of integrally welded piping attachments that have a base metal design thickness of 3/4" or greater.

HASIS FOR RELIEF:

Pursuant to 10CFR50.55a(a)(3)(i) Detroit Edison is requesting relief from ASME Section XI requirements to perform complete (> 90% coverage) surface examination of all integrally welded piping attachments that have a base metal design thickness of 3/4" or greater.

l The proposed alternative for Fermi is partial nondestructive examination supplemented I

by visual examination. Technicaljustification for the adequacy of the alternative is substantiated by changes in the ASME Code.

This relief request also identifies burdent associated with engineering resource impacts, clamp removal, location restoration, which would represent a burden to existing resources. Identification of these burdens are provided only in support of the need for an alternative. The engineering impacts mentioned are incurred in diverting limited engineering resources away from other tasks.

The structural integrity of the piping pressure boundary including welded attachments was originally demonstrated during construction by meeting the requirements of ASME Section Ill. Design, fabrication, installation, inspection, and examination satisfied the appropriate Code requirements. Construction examinations used techniques similar to those used for inservice examinations (surface NDE methods). During the Fermi Preservice Inspection volumetric examinations were also performed. The construction and preservice examinations were usually completed prior to installation of the support members. Therefore the extent of accessibility is not specifically know until the first inservice examination is completed. Integral attachment locations remaining to be l

l Page1of4 L

examined were compared to locations similar in design and any expected limitations are listed in the table.

The pressure boundary passed the required preservice hydrostatic test and all subsequent presstire tests through the fifth refueling and inspection outage (RF-05).

Complete examinations meeting the coverage requirements of ASME Code Section XI are performed on welds of similar configurations which utilized the same weld techniques, procedures and materials. The welds with complete examinations are subject to similar operating and environmental conditions as the partially examined welds. No service related discontinuities have been discovered on welds fully examined or those partially examined. Additionally, there is no industry history of ASME Class 2 service induced attachment weld failures. It is reasonable to expect that the unexamined portions are also acceptable.

The absence of significant integral attachment weld problems is further evidenced by '

ASME Code Case N-509 which allows a reduced sample size of only 10% of all integral 2

attachments. This Code Case has been approved at other nuclear facilities (e.g., Duane Arnold) and was incorporated into the 1995 Addenda of ASME Section XI. Fermi has not requested to implement this Code Case, which would reduce the inspection population to approximately 19 locations during the first inspection interval. We are asking for partial relief of coverage on specific locations included in the 39 locations where examinations can be performed.

The average surface coverage for the incomplete examinations completed and listed in Table 1 is 87%. To obtain complete Code coverage at each location, the component support would have to be disassembled and the pipe clamp assembly removed.

Temporary line support would have to be evaluated by engineering and installed as necessary, The additional engineering resources, time, field personnel, and radiation exposure required to attain full coverage is not consistent with the minimal risk l

associated with these items, as reflected by plant and industry experience as well as current Code requirements.

)

l Radiation exposure for a best case location assuming a conservative effective (averaged) dose rate of 5mr/hr and a minimum of 16 man hours to remove and reinstall the clamp j

assembly and inspect the location would result in at least 80mr additional exposure per l

~

j location (approximately 640mr minimum accumulated dose). Note that this assumption uses an effective averaged dose rate, and actual dose on a pipe and is often much higher.

Removal of the clamps could actually increase the possibility of damaging other components such as nozzles and penetrations due to additional line stress. Additionally, the time for disassembly and reassembly does not assume mechanical difficulties such as temporary line support, seized bolts, and removal and reinstallation of welded lug retainers from the clamps, that will greatly increase the time and dose impacts.

1.

Page 2 of 4

{-

l ALTERNATIVE EXAMINATION:

Detroit Edison proposes that in addition to the partial surface examination of the exposed portion oflug welds and required base metal volume, that a supplemental visual examination to the extent practical by the examiner be perfonned. Additionally, leakage inspections are performed each inspection period per Category C-II.

Based on the coverage achievable, physical limitations, comparison of the Fermi ISI NDE Program scope as compared to current Code requirements, and low empirical probability of weld failure, Detroit Edison considers the proposed alternative examination to provide an acceptable level of quality and safety.

APPLICAllLE TIME PERIOD:

Reliefis requested for the first 10-year inspection interval.

f I

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l Page 3 of 4 l

L.. _.

RR-A22 Table 1 Limited Examinations Category Weld Percentage Limitation Alternate

/ Item Identification Complete Description Examination C-C/C3.20 PSFW El13146-83% per lug Clamp supplemental 606A L visual C-C/C3.20 SW-E l 1-3151

~90% per lug Clamp at spring supplemental 4WE-4WK expected El l-3151-G05 visual C-C/C3.20 SW-E I l-3151

~90% per lug Clamp at spring supplemental 10WC-10Wil expected El l-3151-G01 visual C-C/C3.20 SW EIl 3158-87% per lug Lugs A,C,D, & F supplemental 583A 583F lugs B & E inaccessible due to lug visual retainers on restraint Ell-3158-G52 C-C/C3.20 SW El1-1158 85% per lug Clamp at spring El 1-3158 supplemental 7WC-7Wil G51 visual C-C/C3.20 PSFW-E41-3162-90 %

Clamp at snubber E41-supplemental 583A F 3162-G20 visual C C/C3.20 PSFW-E41 3172-90 %

Clamp at snubber E41-supplemental 592A-D 3172-Gl9 visual C-C/C3.20 PSFW-E41-3172 80% per lug lug retainers at E41-3172-supplemental 625A-625D Gl4 visual Page 4 of 4

NRC-98-0093 Page 10 t

I I

RELIEF REQUEST RR-A23 5 PAGES

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RELIEF REQUEST RR-A23 COMPONENT FUNCTION / DESCRIPTION:

i Pressure Retaining Piping Welds (see attached Table for identification numbers)

)

l l

SYSTEMS:

Main Steam (B21) l Reactor Recirculation (B31)

Residual Heat Removal (El1)

Feedwater (N21) l ASME CODE CLASS:

j l

Class 1

)

l ASME SECTION XI REQUIREMENTS:

ASME Section XI,1980 Edition including the Winter 1981 Addenda, Subsection lWB, Table IWB-2500-1, Category B-J, item 9.11 requires a volumetric and surface I

examination of circumferential piping welds greater than or equal to 4" diameter. Item B9.12 also requires examination of any intersecting longitudinal seams. Note 3 of Table l

IWB-2500-1 requires that the examination include essentially 100% of the weld length l

and volume specified in figure IWB-2500-8.

l HASIS FOR RELIEF:

i During the course ofinservice examination,6 of 156 Category B-J circumferential welds have been encountered that cannot be fully examined in accordance with ASME Section XI (> 90% oflength and volume). Pursuant to 10CFR50.55a(a)(3)(i) Detroit Edison is l

requesting relief from ASME Section XI requirements to perform complete examinations oflisted piping welds, as described above.

i The alternative proposed for Fermi is partial examination predicated on technical basis.

The technical basis is supported by comparison of the Fermi ISI Program to ASME Code requirements. As detailed in this relief request, the alternative assures that a high level of quality and safety is maintained. The relief request also notes difficulties associated with increasing coverage. Based on the coverage achievable, physical limitations, and comparison of Code requirements to the Fermi program, Detroit Edison considers the proposed alternative examination to provide an acceptable level of quality and safety.

ALTERNATIVE EXAMINATION:

Partial examination of each weld to the greatest extent possible using appropriate surface and ultrasonic examination methods. Additionally, leakage inspections performed at the completion of each refueling outage per Category B-P wlude all of these welds, The extent of partial examination and technical justification for each is provided below:

l Page1of5 l

O Main Steam (B21)

Category Weld Percentage Limitation Alternative

/ Item Identification Complete Description Examination B-J/B9.11 SW PS2-B3-A 78% UT Whip Restraint Examine 40% MT accessible area B-J/B9.12 SW-PS2-B3-100% UT Whip Restraint Examine ALD 42%MT accessible area B-J/B9.11 SW-PS2-C3-A 100% UT Whip Restraint Examine 44%MT accessible area B-J/B9.12 SW-PS2-C3-100% UT Whip Restraint Examine ALD 42%MT accessible area These carbon steel welds were selected for exam based on a moderate stress category as defined in the Fermi UFSAR. This is a more conservative approach to selecting welds than a supplemental random selection to bring the examination sample to 25%, as specified in the Code. The moderate stress category results in a main steam inspection sample of 42% of all circumferential welds. The increased inspection sample is comprised of welds with the highest probability of failure and results in added assurance of system integrity. The inspection sample set is larger than required by ASME Code and will provide for reliable detection of degradation representative of the weld population.

Inspections completed through the fillh refueling outage (RF-05) have detected no service induced defects in any carbon steel piping welds subject to ISI. There is no decrease in the ability to detect system degradation as a result of these limitations.

Removing the obstructions to facilitate further inspection of these welds would increase manpower and radiation dose without a compensating increase in plant safety.

Reactor Recirculation (B31)

Category Weld Percentage Limitation Alternative

/ Item Identification Complete Description Examination B-J/B9.11 FW-RS-2-A5 86% PT Pump insulation Examine

>90% UT Support Ring &

accessible area Brackets This stainless steel weld is a low stress random selection. The weld was given an IGSCC mitigation treatment (Induction lieat Stress Improvement) as defined in NUREG-0313 Rev. 2, prior to service. Fermi has also implemented an augmented inspection program in accordance with Generic Letter 88-01. The combined Code and GL-88-01 niections result in greater than 50% of all Reactor Recirculation System welds being inspected each interval. The inspection sample set is sufficiently large to provide for reliable detection of representative degradation. There is no decrease in the ability to detect system degradation as a result of this limitation. Removing the obstructions to facilitate further inspection of this weld would increase manpower and radiation dose without a compensating increase in plant safety. Detroit Edison believes this attemative provides an acceptable level of quality and safety.

Page 2 of 5

t e

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RIIR(El1)

Category Weld Percentage Limitation Alternative j

/ Item Identification Complete Description Examination B-J/B9.11 FW 611-2299-

>50% UT Tee Configuration Examine l

OW1 100% PT Limits UT Only accessible area

]

This stainless steel tee-to-pipe weld is a high stress weld selection. The weld was radiographer during construction and satisfied Section ill acceptance criteria. There are also six other high stress locations in the RIIR system that will be fully examined. The j

surface of the weld is fully accessible for liquid penetrant examination. Ultrasonic

{

- examination is limited to effective scanning from the pipe side only because of reducing-4

. tee configuration. The ultrasonic examination covers all of the base material on the pipe j

' side of the weld and the weld root area. Because the examination covers the weld root i

area which is the thinnest section of this pipe-to-tee weld zone, there is adequate j

assurance that IGSCC or fatigue or cracking could be detected. Additionally, two l

adjacent welds on both ~ sides of this weld are fully examined. Fermi has also j

implemented an augmented inspection program in accordance with Generic Letter 88-01.

The combined Code and GL-88-01 selections result in greater than 50% of all susceptible welds being inspected each interval. The inspection sample set is sufficiently large to provide for reliable detection of representative degradation. There is no decrease in the j

ability to detect system degradation as a result of this limitation.

Radiographic examination was considered as an alternative but has the following

{

li.mitations. The radiation emitted from the pipe would negatively impact the sensitivity of the examination. Perfomlance of the examination would take approximately one shift to complete and prevent other outage activities from be performed during the radiography evolution. Radiographic examination of the weld would require draining of the l

recirculation loop piping and a portion of RHR. This would require pluggingjet pumps i

and recirc suction lines inside the vessel. RHR Shutdown cooling would not be available to remove decay heat. For these reasons radiography is not a feasible alternative for the ultrasonic examination.

i 1

- Because of the acceptable initial condition, pressure test history and continued perfonnance, the capability to complete the surface exam and greater than 50 percent of the exam volume including the root area,it is reasonable to conclude there is no

- significant impact on the level of plant quality and safety by the reduction in volumetric coverage of this weld.. Detroit Edison believes this alternative provides an acceptable

- level of quality and safety I

i I.

Page 3 of 5

a I

Feedwater (N21)

Category Weld Percentage Limitation Alternative

/ Item Identification Complete Description Examination B-J/B9.11 FW-N21-2336-

~76% UT Tee to Valve Examine l

OW1 100% MT Configuration accessible area This carbon steel tee-to pipe weld is a moderate stress weld selection category as defined in the Fermi UFSAR. The moderate stress category results in an inspection sample of 28% of all Category B9.11 circumferential welds. The increased inspection sample is comprised of welds with the highest probability of failure and results in added assurance of system integrity. This is a more conservative approach to selecting welds than a supplemental random selection to bring the examination sample to 25%, as specified in the Code. The inspection sample set exceeds ASME Code requirements and is sufficiently large to provide for reliable detection of system degradation.

The weld was radiographer during construction and satisfied Section III acceptance criteria. The valve body and weld ends were also radiographer in accordance with NB 2570. The surface of the weld is fully accessible for magnetic particle examination.

Ultrasonic examination is limited because of tee-to-valve configuration. The ultrasonic examination does cover the weld and the weld root area in at least one direction base material on the valve side is not fully covered in two directions. The adjacent weld, which is also a moderate stress weld is ftdly examined. Inspections completed through the fifth refueling outage (RF-05) have detected no reportable service induced defects in any carbon steel piping welds subject to ISI.

Because of the acceptable initial condition, pressure test history and continued performance, the capability to complete the surface exam and approximately 50 percent of the exam volume including the root area, it is reasonable to conclude there is no significant impact on the level of plant quality and safety by the reduction in volumetric coverage of this weld. Because inspection sample exceeds ASME Code requirements, there is no decrease in the ability to detect system degradation as a result of this limitation. Detroit Edison believes this alternative provides an acceptable level of quality and safety Feedwater (N21)

Category Weld Percentage Limitation Alternative

/ Item Identification Complete Description Examination B-J/89.11 FW-N21-2336-50% UT Sweepolet to Valve Examine 1WO3 100% MT Configuration accessible area This carbon steel reducer-to-valve weld is a high stress weld selection. The weld was radiographer during construction and satisfied Section III acceptance criteria. The valve body and weld ends were also radiographer in accordance with NB 2570. There are also eleven other high stress locations (includes terminal ends) in the Feedwater system that will be fully examined. The surface of the weld is fully accessible for magnetic particle Page 4 of 5

,c,..

examination. Ultrasonic examination is limited to effective scanning from the crown of the weld. The ultrasonic examination covers most of the base material on both sides of the weld in one direction. The entire weld and root can be scanned in the circumferential direction. Additionally, the high stress weld directly adjacent to this weld is fully examined.

There are over 50 high stress carbon steel weld selections spread among the systems subject to inservice inspection. The Fermi Class 1 inspection population for all systems exceeds ASME Code requirements by 15 welds because moderate stress welds are included in the selection basis. The welds that were selected are the most probable locations for stress related failure. The selection methodology used was more stringent than required by Code. Because of the selection methodology and sample size there is no reduction in capability to detect system degradation as compared to Code requirements.

l Through the fifth refueling outage (RF-05) there have been no service induced defects detected. Industry experience does not indicate cracking of carbon steel butt welds to be a problem.

l l

Radiographic examination was considered as an alternative but is undesirable for the L

following reasons. Performance of the examination would prevent drywell outage activities from being performed during the radiography evolution and would add critical -

path time to the outage schedule. The benefit ofincreasing the coverage of this weld by radiographic examination has only a small potential ofincreasing plant safety margin and a disproportionate impact on plant resources. Since the Fermi inspection program exceeds ASME Code requirements for the sampling program this attemative is not considered to be necessary.

Because of the acceptable initial condition, pressure test history and continued performance, the capability to complete the surface exam and approximately 50 percent of the Code exam volume, it is reassnable to conclude there is no significant impact on the level of plant quality and safet-[oy the reduction in volumetric coverage of this weld.

Detroit Edison believes this alter 6ative provides an acceptable level of quality and safety 1

APPLICABLE TIME PERIOD:

Reliefis requested for the first 10-year inspection interval.

(

Page 5 of 5

NRC-98-0093 l

Page11 I

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l RELIEF REQUEST RR-A24 2 PAGES PLUS CASE N-524 I

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RELIEF REQUEST RR-A24

[OMPONENT FUNCTION / DESCRIPTION:

Class 1 & 2 Pressure Retaining Longitudinal Piping Welds SYSTEM:

All systems included in the ISI NDE Program ASME CODE CLASS:

Class 1 & 2 l

ASME SECTION XI REQUIREMENTS: ASME Section XI,1980 Edition including the Winter 1981 Addenda, Table IWB-2500-1, Category B-J, Note 4 requires examination of at least one pipe-diameter length but not mere than 12 inches of each I

longitudinal weld intersecting the circumferential welds required to be examined by Category B-J. Category C-F requires examination of 2 S of the long seam at the intersecting circumferential weld.

BASIS FOR RELIEF; Pursuant to 10CFR50.55a(a)(3)(i) Detroit Edisor,is requesting relief from ASME Section XI requirements to examine each longitudinal weld as described above.

Detroit Edison is proposing to implement the alternative specified in ASME Code Case l

N-524 (copy attached). This Code Case is ASME approved indicating Code Committee consensus that the alternative will provide essentially equisalent results, i.e., that restricting the long seam exam to the intersecting zone of the circumferential weld will not adversely affect examination results. Detroit Ea. son agrees with the Code Committee that use of the alternative described in this Code Case will provide an acceptable level of quality and safety.

Longitudinal welds are fabricated during the product form manufacturing process under conaolled shop conditions. This results in high quality welds with even stress distribution.

The welds were subjected to full radiography and pressure testing in accordance with ASME Section III.

There has been no history of degradation ofIc ngitudinal seam welds beyond the zone of the intersecting circumferential weld. When cracking does occur, such as IGSCC in austenitic stainless materials, it initiates and will be evident in the zone of the circumferential weld. The absence of significant longitudinal weld problems is evidenced by ASME Code Case N-524, which has beer. tentatively approved without restrictions in Draft Guide DG 1050. This Code Case has been approved at other nuclear facilities (e.g.

Browns Ferry) and was incorporated into the 1995 Addenda of ASME Section XI.

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Because Code Case N-524 eliminates examn ation of the longitudinal we!d beyond the intersection with a circumferential weld, use of h 524 can significantly reduce examination time requirements, thus reducing the cost of such examinations and unnecessary radiation exposure to examination personnel. In addition to the man-rem b

savings obtained by reduced examination time, additional radiological benefits can be realized due to the significant reduction ofdose and effort associated with removing / reinstalling insulation and interferences (component supports) and preparing the welds for examination.

ALTERNATIVE EXAMINATION:

Code Case N-524 allows for the examination of the intersecting longitudinal weld in the zone required by the circumferential weld as follows:

(a) W hen only a surface examination is required, examination oflongitudinal piping welds is not required beyond those portions of the welds within the examination boundaries ofintersecting circumferential welds.

(b) When both surface and volumetric examinations are required, examination of

)

longitudinal piping welds is not required beyond those portions of the welds within the examination boundaries ofintersecting circumferential welds provided the following requirements are met:

(1) Where longitudinal welds are specified and locations are known, examination requirements shall be met for both transverse and parallei flaws at the intersection of the welds and for that length oflongitudinal weld within the circumferential weld examination volume; (2) Where longitudinal welds are specified but locations are unknown, or the existence oflongitudinal welds is uncertain, the examination requirements shall be met for both transverse and parallel flaws within the entire examination volume ofintersecting welds.

APPLICABLE TIME PERIOD:

Reliefis requested for the remainder of the first 10-year interval or until Code Case N-524 is incorporated into Regulatory Guide 1.147.

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E o

CASE a

N-524 I

CASES OF ASME BOILER AND PRESSURE VESSEL CODE Approval Data: August 9,1993 See Numericalindex for expiration and any reet5rmatson dates.

Case N-524 Alternative Examination Requirements for Longitudinal Welds in Class 1 and 2 Piping Section XI, Division 1 Inquur What alternathe requirements may be ap-plied to the surface and volumetric examination of longitudinal piping weR specificc' in Table IWB-2500-1, Examination Category B-J, s able IWC-2500-1, Examination Categories C-F-1 and C-F-2 (Exam-ination Category C-F prior to Winter 1983 Adden-da), and Table IWC 2520 Examination Category C.

G (1974 Edition, Summer 1975 Addenda)?

Reply It is the opinion of the Comndttee that the following shall apply:

(a) When only a surface examination is required, examinatim of longitudinal piping welds is not re-quired beyond those portiona of the welds within the examination boundaries of intersecting circumfer-ential welds.

(b) When both surface and volumetric examina.

tions are required, examination oflongitudinal piping welds is not required beyond those portions of the welds within the examination boundaries of inter-secting circumferential welds provided the following requirements are met.

(1) Where longitudinal welds are specified and locations are known, examination requirements shall be met for both transverse and parallel flaws at the j

i intersection of the welds and for that length oflon.

I gitudinal weld within the circumferential weld ex-amination volume; l

(2) Where longitudinal welds are specified but locations are unknown, or the existence of longitu-i dinal welds is uncertain, the examination require-ments shall be met for botn transverse and parallel i

flaws within the entire examination volume ofinter-secting circumferential welds.

903 SUPP 6 - NC

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