ML20117C047

Forwards Response to RAI Re Second Ten Yr Interval ISI Program Plan

ML20117C047
Person / Time
Site:	Catawba
Issue date:	08/19/1996
From:	Mccollum W DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
TAC-M95255, NUDOCS 9608270260
Download: ML20117C047 (39)

Text

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I Dukelkrer Congwny IntuwR AfoCount.JR Catau ba Nuclear Generation ikpartment Vicehesident 48(M)ConcordRoad (8tG)R31-3M Office Wik, SC29745 (8(22831-3426 Fax

'DUKEPOWER August 19,1996

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U.S.' Nuclear Regulatory Commission Attention: Document Control Desk Washington,HD.C'. 20555

Subject:

Catawba Nuclear Station, Unit 2 Docket No. 50-414 Second Ten Year Interval Inservice Inspection Program Plta Reply to~ Request for Additional Information (TAC No. M95255) j

Reference:

Letter from Peter S. Tam, NRC to William R.

McCollum, Catawba Nuclear Station dated July 10,1996 1

Gentlemen:

Please find attached Catawba's reply to the subject request for. additional information.

For convenience, each NRC l

question in the reference letter has been restated, followed l

by our response.

i As requested, a copy of this-response is being-sent to Michael T. Anderson at the INEL Research Center.

Should you have any questions concerning this reply, please call Devereux Tower, Catawba Nuclear Station, Regulatory i

l Compliance at (803).831-3419.

'l Very truly yours, 7

I i

-W.R. McCollum, Jr.

dN AJH/JEC 2Shkchment i

9608270260 960819 PDR ADOCK 05000414 E)

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v Document Control Desk Page 2 August 19,1996 xc (with attachment):

S.D.

Ebneter, Regional Administrator Region II R.J.

Freudenberger, Senior Resident Inspector 1

P.S.

Tam, Senior Project Manager ONRR Michael T. Anderson INEL Research Center 2151 North Boulevard i

PO Box 1625 Idaho Falls, Idaho 83415-2209 I

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REPLY TO REQUEST FOR ADDITIONAL INFORMATION SECOND TEN YEAR INTERVAL INSPECTION PROGRAM PLAN i

AND ASSOCIATED REQUESTS FOR RELIEF FOR l

CATAWBA NUCLEAR STATION UNIT 2 i

1 Address the degree of compliance and/or exceptions to augmented examinations that have been established by the NRC when added assurance of structural reliability is deemed necessary. Examples of documents that address augmented l

examinations are:'

(1)

Branch Technical Position MEB 3-1, "High Energy Fluid Systems, Protection

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Against Postulated Piping Failures in Fluid Systems Outside Containment";

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Response

As outlined in Section 6.6.8 of the Catawba FSAR, the following is Duke Power's position regarding MEB 3-1:

The augmented inservice inspection program defm' ed in Standard Review Plan Section

" Inservice Inspection of Class 2 and 3 Components" in topic 6.6, paragraph 11.8 will be implemented as follows:

1.

If " break exclusion" is claimed, then an augmented inservice program in accordance with Standard Review Plan Section " Inservice Inspection of Class 2 and 3 Components" in topic 6.6, will be implemented.

2.

Where breaks are not assumed to be excluded, breaks will be postulated in J

accordance with the criteria of Branch Technical Position MEB 3-1, " Postulated Break and Leakage Locations in Fluid Systems Piping Outside Containment" of Standard Review Plan Section " determination of Break Locations and Dynamic Effects Associated with the Postulated Rupture of Piping"in topic 3.6.2, and the plant will be designed to withstand the consequences of these breaks, including the full dynamic effects of the breaks. These lines will receive the normal inservice inspection of Article IWC-2000 of the reference codes as defined in 10 CFR 50.55a(g) to the extent practical.

3.

Where guard pipes are used on processed pipes to mitigate the consequences of a nipture of the process pipe, the guard pipes will be designed for the full dynamic effects of a longitudinal or circumferential break of the process pipe. Inspection ports have been provided where possible, and these lines will receive the normal j

inservice inspection of Article IWC-2000 of the reference code of(2) above.

1

The areas subject to examination and the methods of examination are in accordance with the above reference code. In general, ultrasonic examination will be the technique employed for volumetric examinations however, radiography will be used for the main steam welds which are encased in guard pipe.

Catawba Nuclear Station FSAR, Table 6-103 lists those lines requiring augmented inservice inspection. The weld listing and scheduling will be contained in the Catawba Nuclear Station Inservice Inspection Plan. This plan will be implemented effective August 19,1996 for Unit 2. These inspections are listed as Item Number G02.001 in the Catawba Unit 2 ISI Plan.

(2)

Regulatory Guide 1.150, Ultrasonic Testing ofReactor Vessel Welds During Preservice and Inservice Examinations;

Response

Duke Power complies with Regulatory Guide 1.150 including " Appendix A",

Ultrasonic Testing of Reactor Vessel Welds during Preservice and Inservice Examinations, with the exception of Regulatory Position Paragraph C.7a.

Regulatory Guide 1.150 recommends that the best estimate of error band involved in sizing of flaws be included in the report. Duke Power takes exception to this recommendation on the basis that unless actual flaw dimensions are known, error band cannot be reliably calculated. No estimates of error band will be made.

(3)

Code of Federal Regulations, Part 10,50.55a(g)(6)(li)(A), which states that all licensees must augment their reactor vessel examinations by implementing once, during the inservice inspection interval in effect on September 8,1992, the examination requirements for reactor vessel shell welds specified in Item Bl.10 of Examination Category B-A of the 1989 Code. In addition, all previously granted reliefs for Item B1.10, Examination Category B-A, for the interval in effect on September 8,1992, is revoked by the new regulation. For licensees with fewer than 40 months remaining in the interval on the effective date, deferral of the augmented examination is permissible with the conditions stated in the regulations.

Response

On September 8,1992, Catawba Unit 2 was in the First ISI Interval which was governed by the 1980 Edition, Winter 81 Addenda, of Section XI. During EOC 7 of the First Interval, Duke Power ultrasonically examined 100% of the length of each of the Catawba Unit 2 Reactor Vessel Shell Welds. For weld examinations which did not meet the criteria for 90% coverage of the examination volume, requests for relief were submitted.

A request for an alternative to the requirements for augmented reactor vessel examination, as stipulated in 10 CFR 50.55a(g)(6)(ii)(A), is currently being developed by Duke Power Company and will be submitted per 10 CFR 50.55a(g)(6)(ii)(A(5) for Catawba Units 1 and 2 in the near future.

Discuss these and any other augmented examinations that may have been incorporated in the Catawba Nuclear Station, Unit 2, Second Ten-Year Inspection IntervalInservice Inspection Program, Revision 0.

Response

In addition to the augmented examinations discussed in 1,2 and 3 above, Duke Power Company has also committed to the following augmented examinations at Catawba Unit 2:

1.

Inservice inspection on the Reactor Coolant Pump Flywheels shall be performed in accordance with Regulatory Guide 1.14 Revision 1 (Catawba FSAR 5.4.1.5)

These inspections are Item Numbers G01.001 in the Catawba Unit 2 ISI Plan.

2.

Ultrasonic inspections on specific Class 1 Piping Welds and Bends per NRC Bulletin 88-08. These inspections are Item Number G03.001 in the Catawba Unit 2 ISI Plan.

Paragraph 10 CFR 50.55a(b)(2)(iv) requires that certain ASME Code Class 2 piping welds in the Residual Heat Removal (RHR), Emergency Core Cooling (ECC), and Containment Heat Removal (CHR) systems be examined. Portions of these systems are critical to the safe shut down of the plant and should not be completely excluded from inservice volumetric examination based on piping wall thickness. In consideration of the safety significance of the subject systems, discuss any plans or schedules for the examination of a sample of these welds to assure the continued integrity of thin-wall piping. (A 71/2% sample is consistent with the extent of examination required for Class 2 piping.)

Response

Paragraph 10 CFR50.55a(b)(2)(iv)(A) states " Appropriate Code Class 2 pipe welds in Residual Heat Removal Systems (RHR), Emergency Core Cooling Systems (ECC) and Containment Heat Removal Systems (CHR) must be examined".

The 1989 Edition of Section XI, Table IWC 2500-1, Categories C-F-1 and C-F-2, excludes welds less than 3/8 inch nominal wall thickness for pipe greater than 4 inches and welds less than 1/5 inch nominal wall thickness for pipe greater than or equal NPS 2 inches and less than or equal to NPS 4 inches. At Catawba Unit 2, Residual Heat Removal (ND), Safety Injection (NI), Containment Spray (NS) and Chemical and

Volume Control (NV) Systems addressed by Paragraph 10 CFR 50.55a(b)(2)(iv)(A) are fabricated from thin wall pipe. The subject welds within the ISI boundaries of these systems do not meet the criteria requiring inspection under Examination Categories C-F-1 and C-F-2 and therefore were not included in the ISI sample for inspection for the Second Interval. These welds however, were included in the total weld count for Examination Categories C-F-1 and C-F-2 to which the 7.5% sampling rate is applied.

The licensee has provided tables of the scheduled examinations for the second interval, by outage. However, in order to verify that the appropriate percentage of examinations areas are being scheduled by period and for the interval, the total number of examination areas, summarized by Examination Category and the number of examination areas scheduled for each period and for the interval is required. Provide a summary of the total number of examination scheduled for each period and for the interval. This information will aid in the verification that the program schedule is in compliance with Code requirements.

Response

(See attachment, pages 1-32)

Please note that the summaries shown on the following attachment excludes Examination Categories B-E, B-P, C-H, D-A(Pressure Retaining Components Only), D-B (Pressure Retaining Components Only) and D-C (Pressure Retaining Components Only).

These categories for Catawba Unit 2 are included in the Duke Power Company Inservice Inspection Pressure Test Plan for Oconee, McGuire and Catawba Nuclear Stations.

Attachment Catawba Unit 2 Examination Category Summaries 1

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Catawba 2 Second IntervalISI Plan l

Examination Summary Category B-A Pressure Retaining Welds in Reactor Vessel Class 1 TotalClass 1 Boundary Welds:

24 l

Total welds required for second interval:

24 Total welds for second interval (requested by plant) 24 l

Welds (first period) 6.5 27.08 %

Welds (second period + first period) 6.5 27.08 %

Welds (third period + second period + first period) 24 100 %

• Deferral of inspection to end of interval permissible, per Table IWB-2500-1 l

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Page 1 of 32 4

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Catawba 2 Second IntervalISI Plan i

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Examination Summary l

1 Category B B Pressure Retaining Welds in Vessels Other Than Reactor Vessels l

Class 1 -

TotalClass 1 Boundary Welds:

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Total welds required for second interval:

5 l

Total welds for second interval (requested by plant) 5 i

Welds (first period) 1 20 %

i Welds (second period + first period) 3 60 %

l Welds (third period + second period + first period) 5 100 %

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Catawba 2 Second IntervalISI Plan

- Examination Summary Category B D, Full Penetration Welds of Nonles in Vessels Class 1 l

TotalClass 1 Boundary Welds:

36 i

Total welds required for second interval:

36 Total welds for second interval (requested by plant) 36 Welds (first period) 12 33.33 %

Welds (second period + first period) 20 55.55 %

Welds (third period + second period + first period 36 100 %

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Catawba 2 Second IntervalISI Plan Examination Summary Category B F, Pressure Retaining Dissimilar Metal Welds Class 1 Total Class 1 Boundary Welds:

46 Total welds required for second interval:

46 Total welds for second interval (requested by plant) 46 Welds (first period) 14 30.43 %

Welds (second period + first period) 28 60.86 %

Welds (third period + second period + first period 46 100 %

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Catawba 2 Second IntervalISI Plan Examination Summary Category B G 1, Pressure Retaining Bolting, Greater Than 2 in. In Diameter Class 1 TotalClass 1 Items:

224 Total items required for second interval:

224 Total items for second interval (requested by plant) 224 Items (first period) 73 32.58 %

Items (second period + first period) 147 65.62 %

Items (third period + second period + first period 224-100 %

• 4 items (B06.190's) will be examined only if pump disassembled, per Table IWB.2500-1 l

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t Catawba 2 Second IntervalISI Plan Examination Summary Category B.G 2, Pressure Retaining Bolting,2 in. and Less in Diameter Class 1 -

Total Class 1 Items:

59 Connections Total items required for second interval:

29 Connections Total items for second interval (requested by plant) 29 Connections Items (first period) 9 Connections 31.03 %

ltems (second period + first period) 19 Connections 65.51 %

Items (third period + second period + first period) 29 Connections 100 %

• 1 item (B07.080) will be examined only if CRDM disassembled, per Table IWB-2500-1 Page 6 of 32

Catawba 2 Second IntervalISI Plan Examination Summary l

Category B-H, Integral Attachments for Vessels Class 1 I

TotalClass 1 Boundary Welds:

8 Total welds required for second interval:

8 Total welds for second interval (requested by plant) 8 Welds (first period) 2 25 %

Welds (second period + first period) 4 50 %

i Welds (third period + second period + first period) 8 100 %

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Catawba 2 Second IntervalISI Plan i

Examination Summary l

Category B J, Pressure Retaining Welds in Piping Classi Total Class 1 Boundary Welds:

841 Total welds required for second interval:

211 Total welds for second interval (requested by plant) 222 Welds (first period) -

64 28.82 %

Welds (second period + first period) 142 63.% %

Welds (third period + second period + first period) 222 100 %

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4 Catawba 2 Second IntervalISI Plan Examination Summary Category B K-1, Integral Attachments for Piping, Pumps, and Valves Class 1 Total Class 1 Boundary Welds:

0 Total welds required for second interval:

0 Total welds for second interval (requested by plant) 0 Welds (first period) 0

- Welds (second period + first period) 0

' Welds (third period + second period + first period) 0 N/A for Catawba Unit 2 Page 9 of 32

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Catawba 2 Second IntervalISI Plan Examination Summary Category B L-2, Pump Casings Internal Surfaces Class 1 TotalClass 1 Boundaryitems:

4 i

Total items required for second interval:

4 Total items for second interval (requested by plant) 4 Items (first period) 4*

scheduled each outage Items (second period + first period) 4*

scheduled each outage items (third period + second period + first period) 4*

scheduled each outage

• Only one pump required to be examined per interval Examine only when disassembled, per Table IWB-2500-1 i

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Catawba 2 Second IntervalISI Plan Examination Summary Category B M 1, Pressure Retaining Welds in Valve Bodies Class 1 TotalClass 1 Boundary Welds:

9 Total welds required for second interval:

9 Total welds for second interval (requested by plant) 9 Welds (fira period) 3 33.33 %

Welds (second period + first period) 3 33.33 %

Welds (third period + second period + first period) 9 100 %

• Deferral permissible to end of interval, per Table IWB-2500-1 l

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Catawba 2 Second IntervalISI Plan Examination Summary

. Category B.M.2, Valve Bodies Class 1' TotalClass 1 Boundaryitems:

31 Total items required for second interval:

31 Total items for second interval (requested by plant) 31 Items (first period) 31 Scheduled each outage items (second period + first period) 31 Scheduled each outage items (third period + second period + first period) 31 Scheduled each outage

• Deferral permissible to end of interval and Examination is required only when valve is disassembled, per Table IWB-2500-1 "l

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Page 12 of 32

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n Catawba 2 Second IntervalISI Plan Examination Summary Category B N-1, Interior of Reactor Vessel 5

Class 1 i

TotalClass 1 BoundaryItems:

3 Total items required for second interval.

3-Total items for second interval (requested by plant) 3 j

ltems (first period) 1 33.33 %

Items (second period + first period) 2 66.66 %

Items (third period + second period + first period) 3 100 %

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4 Catawba 2 Second IntervalISI Plan Examination Summary l

Category B N 2, Integrally Welded Core Support Structures and Interior Attachments to Reactor Vessels Class 1 TotalClass 1 BoundaryItems:

2 Total items required for second interval:

2 Total items for second interval (requested by plant) 2 Items (first period) 0%

Items (second period + first period) 0%

Items (third period + second period + first period) 2 100 %

• Deferral permissible to end of interval, per Table IWB-2500-1 l

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l Catawba 2 Second IntervalISI Plan i

Examination Summary 1

Category B N-3, Removal Core Support Structures Class 1 TotalClass 1 Boundaryitems:

1 Total items required for second interval:

.1 Total items for second interval (requested by plant) 1 Items (first period)-

0 0%

Items (second period + first period) 0 0%-

Items (third period + second period + first period) 1 100 %

• Deferral permissible to end ofinterval, per IWB 2500-1 I

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Page 15 of 32

Catawba 2 Second IntervalISI Plan Examination Summary Category B-0, Pressure Retaining Welds in Control Rod Housings Class 1 TotalClass 1 Boundary Welds:

24 Total welds required for second interval:

3 Total welds for second interval (requested by plant) 3 Welds (first period) 1 33.33 %

Welds (second period + first period) 1 33.33 %

Welds (third period + second period + first period) 3 100 %

• Deferral permissible to end of interval, per Table IWB-2500-1 i

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Page 16 of 32

Catawba 2 Second IntervalISI Plan Examination Summary Category B-Q, Steam Generator Tubing

• Steam Generator Tubing Plan is prepared and maintained by the Diversified Services Group of the Duke Power Company's Electric System Support Department, as required by the Catawba Nuclear Station's Technical specifications, 1

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i Catawba 2 Second IntervalISI Plan

' Examination Summary Category C.A, Pressure Retaining Welds in Pressure Vessels Class 2 TotalClass 2 Boundary Welds:

54 Total welds required for second interval:

34 Total welds for second interval (requested by plant) 34 Welds (first period) 8 23.53 %

Welds (second period + first period) 19 55.88 %

Welds (third period + second period + first period))

34 100 %

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i' Catawba 2 Second IntervalISI Plan Examination Summary Category C-B, Pressure Retaining Nonle Welds in Vessels Class 2

. Total Class 2 Boundary Welds:

23 Total welds required for second interval:

10 Total welds for second interval (requested by plant) 10 Welds (first period) 2 20 %

Welds (second period + first period) 6 60 %

Welds (third period + second period + first period) 10 100 %

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Catawba 2 Second IntervalISI Plan Examination Summary Category C-C, Integral Attachments for Vessels, Piping, Pumps and Valves Class 2 Total Class 2 Boundary Welds:

79 Total welds required for second interval:

77 Total welds for second interval (requested by plant) 77 Welds (first period) 26 33.76 %

Welds (second period + first period) 50 64.93 %

Welds (third period + second period + first period) 77 100 %

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t Catawba 2 Second IntervalISI Plan i

Examination Summary Category C D, Pressure Retaining Bolting, Greater Than 2 in. In Diameter Class 2 TotalClass 2 Items:

0 Total items required for second interval:

0 Total items for second interval (requested by plant) 0 Items (first period) 0 Items (second period + first period) 0 Items (third period + second period + first period 0

N/A for Catawba Unit 2 l

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L Catawba 2 Second IntervalISI Plan Examination Summary Category C F 1, Pressure Retaining Welds in Austenitic Stainless Steel or High Alloy Piping Class 2 Total Class 2 Category C-F-1 Welds:

3362 Total welds required for second interval:

255 Total welds for second interval (requested by plant) 277 l

Welds (first period) 87 31.40 %

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Welds (second period + first period) 177 63.89 %

l Welds (third period + second period + first period) 277 100 %

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Catawba 2 Second IntervalISI Plan Examination Summary Category C-F 2, Pressure Retaining Welds in Carbon or Low Alloy Steel Piping 1

Class 2 Total Class 2 Category C-F-2 Welds:

493 Total welds required for second interval:

37 Total welds for second interval (requested by plant) 46 Welds (first period) 13 28.26 %

Welds (second period + first period) 30 65.21 %

Welds (third period + second period + first period) 46 100 %

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Catawba 2 Second IntervalISI Plan i

l Examination Summary l

Category C-G, Pressure Retaining Welds in Pumps and Valves l

Class 2 '

l Total Class 2 Pressure Retaining Welds in Pumps and Valves:

54 Total required for second interval:

22 Total welds for second interval (requested by plant) 22 l

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- Welds (first period) 6 27.27 %

l Welds (second period + first period) 13 59.00 %

' Wclds (third period + second period + first period) 22 100 %

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i Catawba 2 Second IntervalISI Plan Examination Summary Category D A, Systems in Support of Reactor Shutdown Function There are no Integral Attachments in this category for Catawba Unit 2 l

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Catawba 2 Second IntervalISI Plan Examination Summary Category D-B, Systems in Support of Emergency Core Cooling, Containment Heat Removal, Atmosphere Cleanup, and Reactor Residual Heat Removal j

Class 3 Total Class 3 Boundary Welds:

25 Total welds required for second interval:

25 i

Total welds for second interval (requested by pl.mt) 25 i

Welds (first period) 7 28 %

Welds (second period + first period) 16 64 %

Welds (third period + second period + first period) 25 100 %

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Catawba 2 Second IntervalISI Plan Examination Summary Category D.C Systems in Support of Residual IIcat Removal from Spent Fuel Storage Pool 4

There are no Integral Attachments in this category for Catawba Unit 2 Page 27 of 32

Catawba 2 Second IntervalISI Plan Examination Summary Category F A Supports,(Class 1 Piping Supports)

Class 1 Total Class 1 Boundary Piping Supports:

197 Total supports required for second interval:

50 Total supports for second interval (requested by plant) 60

- Supports (first period) 15 25 %

Supports (second period + first period) 37 61.67 %

Supports (third period + second period + first period))

60 100 %

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l Catawba 2 Second IntervalISI Plan l

Examination Summary Category F.A Supports,(Class 2 Piping Supports)

Class 2 Total Class 2 Boundary Piping Supports:

1161 Total required for second interval:

175 Total supports for second interval (requested by plant) 209 Supports (first period) 71 33.97 %

Supports (second period + first period) 140 66.98 %

Supports (third period + second period + first period) 209 100 %

Page 29 of 32

Catawba 2 Second Interval ISI Plan Examination Summary Category F.A Supports,(Class 3 Piping supports)

Class 3 Total Class 3 Boundary Piping Supports:

919 Total required for second interval:

92 Total supports for second interval (requested by plant) 123 Supports (first period) 36 29.26 %

Supports (second period + first period) 73 59.34 %

Supports (third period + second period + first period) 123 100 %

Page 30 of 32

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Catawba 2 Second IntervalISI Plan 1

Examination Summary

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Category F A Supports,(Class 1,2 and 3 Supports, Other han Piping) 1 Total Class 1,2 and 3 Boundaiy Supports:

84 l

Total required for second interval:

41 Total supports for second interval (requested by plant) 41 Supports (first period) 13 31.70 %

Supports (second period + first period) 27 65.85 %

Supports (third period + second period + first period) 41 100 %

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Catawba 2 Second IntervalISI Plan Examination Summary Category F A Supports,( Class 1,2 and 3 Snubbers)

Total Class 1,2 and 3 Boundary Snubbers:

225 Total required for second interval:

225 i

Total snubbers for second interval (requested by plant) 225

• 100% of Class 1,2 and 3 Snubbers examined during Outages 2,4 & 6, as required by plant technical specifications i

Page 32 of 32

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