ML111960191

Forwards Operability Assessment App B & Proprietary Rev 0 to C-E Rept CEN-628-P, Verification of Structural Integrity of Abb Ceno SG Welded Sleeve, Per Recent SG Tube Sleeve Indications Discovered at Prairie Island.C-E Rept Withheld

ML111960191
Person / Time
Site:	Zion File:ZionSolutions icon.png
Issue date:	03/25/1996
From:	Hosmer J Commonwealth Edison Co
To:	NRC/IRM
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ML111960192	List: ML111960191
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NUDOCS 9603290356
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CATEGORY 1 RFULATS INFORMATION DISTRIBUTIONOYSTEM (RIDS)

NBR:9603290356 DOC.DATE: 96/03/25 NOTARIZED: YES DOCKET #

Zion Nuelear Power Station, Unit 2, Commonwealth Edis 05000304 AJL1h. NA-M1 AUHOR AFFILIATION H0'S M EP ,j. Coironwealth Edison Co..

RECIP.NAIME RE6fIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Forwards Operability Assessment App B & proprietary Rev 0 to C-E rept CEN-628-P, "Verification of Structural Integrity of C ABB CENO SG Welded Sleeve," per recent SG tube sleeve indications discovered at Prairie Island.C-E rept withheld. A DISTRIBUTION CODE: AP01D COPIES RECEIVED:LTR ENCL SIZE:5/ -1)0 T TITLE: Proprietary Review Distribution - Pre Operating License & Operating R NOTES:

G RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD3-2 LA 1 1 PD3-2 PD, 1 1 SHIRAKI,C 1 1 INTERNAL: ACRS 6 6 01 1 1 OGC/HDS2 1 0 EXTERNAL: NRC PDR 1 0 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN 5D-5(EXT. 415-2083) TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUTIRED: LTTR 12 ENCL . 10

Commonwealth Edison / pany

• 1400 Opus Place Downers Grove, IL 60515-5701 CrnEd March 25, 1996 U. S.. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Attn: Document Control Desk

Subject:

Operability Assessment and Technical Report CEN-628-P, Rev. 0 for Zion Unit 2 Pertaining to ABB Combustion Engineering Nuclear Operations Steam Generator Tube Sleeves NRC Docket Number:50-304

Reference:

March 8, 1996, Meeting between the Nuclear Regulatory Commission and the Commonwealth Edison Company Pertaining to the (ABB-CENO) Sleeves At the Reference meeting, ABB Combustion Engineering Nuclear Operations (ABB-CENO) and the Commonwealth Edison Company (ComEd) as well as other utilities discussed recent steam generator tube sleeve indications discovered at Prairie Island. At that meeting, ABB-CENO stated that they were preparing a Technical Report for utilities which have the CE sleeves installed in their steam generators. The purpose of this Technical Report was to summarize the metallurgical examination results of recently pulled tube samples containing sleeves with Plus Point indications in the weld zone. The report compares the metallurgical to structural integrity and leakage assessment calculations, as well as the laboratory test programs, and concludes that a safety issue does not exist for sleeves left in service with similar indications. This Technical Report entitled, "Verification of the Structural Integrity of the ABB-CENO Steam Generator Welded Sleeve," forms the bases for the operability assessment that was performed for Zion Unit 2. Both the Operability Assessment Appendix B and the Technical Report are enclosed for your review.

9603290356 960325 PDR ADOCK 05000304 P PDR k:nla:zion:cerpt.doc: I A Unicom Company

I Document Control Desk March 25, 1996 Please note that CEN 628-P Rev. 0, "Verification of the Structural Integrity of the ABB-CENO Steam Generator Welded Sleeve," contains information proprietary to ABB Combustion Engineering Nuclear Operations and is supported by an affidavit signed by Combustion Engineering, the owner of the information. The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in Paragraph (b)(4) of Section 2.790 of the Commission's regulations. Accordingly, it is respectfully requested that the information which is proprietary to Combustion Engineering be withheld from public disclosure in accordance with 10 CFR 2.790 of the Commission's regulations.

Correspondence with respect to the proprietary aspects of the items should be addressed to IC. Richard, ABB-CENO Director Operations Licensing.

If you have any questions concerning this correspondence, please contact Denise Saccomando at (708) 663-7283.

Sincerely, ohn B. Hosmer Engineering Vice President Attachments cc: H. Miller, Regional Administrator-Rll C. Shiraki, Zion Project Manager-NRR R. Westburg, Acting Senior Resident Inspector-Zion Office of Nuclear Safety -IDNS k:nla:zion:cerpt.doc:2

AFFIDAVIT PURSUANT TO 10 CFR 2.790 1,I.C. Rickard, depose and say that I am the Director, Operations Licensing, of Combustion Engineering, Inc., duly authorized to make this affidavit, and have reviewed or caused to have reviewed the information which is identified as proprietary and referenced in the paragraph immediately below. I am submitting this affidavit in conformance with the provisions of 10 CFR 2.790 of the Commission's regulations and in conjunction with the applications of; (1) Northern States Power Co., (2) Entergy Operations, Inc., (3) Commonwealth Edison Co., (4)Rochester Gas and Electric Co., and (5)Wisconsin Public Service Corp. for withholding this information.

The information for which proprietary treatment is sought is contained in the following document:

CEN-628-P, Rev. 00-P - "Verification of the Structural Integrity of the ABB CENO Steam Generator Welded Sleeve", March 1996 This document has been appropriately designated as proprietary.

I have personal knowledge of the criteria and procedures utilized by Combustion Engineering in designating information as a trade secret, privileged or as confidential commercial or financial information.

Pursuant to the provisions of paragraph (b)(4)of Section 2.790 of the Commission's regulations, the following is furnished for consideration by the Commission in determining whether the information sought to be withheld from public disclosure, included in the above referenced document, should be withheld.

b

-2

1. The information sought to be withheld from public disclosure, is owned and has been held in confidence by Combustion Engineering. It consists of a review of a welded steam generator tube sleeve installation problem and the evaluation of pulled steam generator tube samples from an affected facility.

2. The information consists of test data or other similar data concerning a process, method or component, the application of which results in substantial competitive advantage to Combustion Engineering.

3. The information is of a type customarily held in confidence by Combustion Engineering and not customarily disclosed to the public. Combustion Engineering has a rational basis for determining the types of information customarily held in confidence by it and, inthat connection, utilizes a system to determine when and whether to hold certain types of information in confidence. The details of the aforementioned system were provided to the Nuclear Regulatory Commission via letter DP-537 from F. M. Stern to Frank Schroeder dated December 2, 1974. This system was applied in determining that the subject document herein is proprietary.

4. The information is being transmitted to the Commission in confidence under the provisions of 10 CFR 2.790 with the understanding that it is to be received in confidence by the Commission.

5. The information, to the best of my knowledge and belief, is not available in public sources, and any disclosure to third parties has been made pursuant to regulatory provisions or proprietary agreements which provide for maintenance of the information in confidence.

6. Public disclosure of the information is likely to cause substantial harm to the competitive position of Combustion Engineering because:

a. A similar product is manufactured and sold by major pressurized water reactor competitors of Combustion Engineering.

b. Development of this information by Combustion Engineering required millions of dollars and thousands of manhours of effort. A competitor would have to undergo similar expense in generating equivalent information.

c. In order to acquire such information, a competitor would also require considerable time and inconvenience to develop an understanding of welded steam generator tube sleeve installation problems and evaluate specific examples based on test or pulled steam generator tube data.

d. The information consists of a review of a welded steam generator tube sleeve installation problem and the evaluation of pulled steam generator tube samples from an affected facility, the application of which provides a competitive economic advantage. The availability of such information to competitors would enable them to modify their product to better compete with Combustion Engineering, take marketing or other actions to improve their product's position or impair the position of Combustion Engineering's product, and avoid developing similar data and analyses in support of their processes, methods or apparatus.

e. Inpricing Combustion Engineering's products and services, significant research, development, engineering, analytical, manufacturing, licensing, quality assurance and other costs and expenses must be included. The ability of Combustion Engineering's competitors to utilize such information without

'A,

-4 similar expenditure of resources may enable them to sell at prices reflecting significantly lower costs.

f. Use of the information by competitors inthe international marketplace would increase their ability to market nuclear steam supply systems by reducing the costs associated with their technology development. In addition, disclosure would have an adverse economic impact on Combustion Engineering's potential for obtaining or maintaining foreign licensees.

Further the deponent sayeth not.

I. . ard, Director Operations Licensing Sworn to before me this /5j day of ,1996 Ndtary Public My commission expires:

• 39

APPENDIX A INITIAL OPERABILITY ASSESSMENT Assessment #96-01283 Rev. 0

1. DESCRIPTION:

Date March 7, 1997 Time 1800 Unit 2 Mode 1 Equipment Part Number (s) 2RC-100,200 Component Description Steam Generators A,C Failure

Description:

This Operability Assessment stems from the from the results of the recent inspections that have occurred at Prairie Island Unit-1 (PI-1) concerning Combustion Engineering (CE) sleeves. During the PI-1 inspection that occurred in the first quarter of 1996, both in-service and baseline eddy current examinations of all sleeves in the No. 12 steam generator were performed using the +Point coil probe. Both circumferential and volumetric indications were identified at the upper sleeve weld. This weld serves as the pressure boundary interface for the repaired tube. The circumferential indications identified on the upper sleeve welds at PI-1 required the tubes to be plugged. Zion Unit 2 has never identified a circumferential indication on the upper sleeve weld. PI-1 identified 51 tubes which had only volumetric indications. Of these 51 tubes 14 were plugged based on a determination that they were within the pressure boundary and 1 tube was removed for metallurgical examination. Therefore, a total of 15 tubes were removed from service for volumetric indications.

Four tubes with circumferential indications and one tube was pulled with a volumetric indication were physically removed from PI-1. The objectives of the sleeved tube removal examination program were to: (1)identify the physical condition(s) present in the sleeve joints which have resulted in the eddy current test indication observed, (2)verify that, if as suspected, indications were the result of installation, and the condition is not detrimental to the structural integrity of the sleeve, and (3)in the unlikely event service induced degradation is the cause, identify the factors affecting the degradation mechanism.

APPENDIX A Preliminary pulled tube examination results have shown that all 5 tubes exhibited "crack like" inclusion with 1 tube exhibiting sleeve "suckback" outside the pressure boundary.

Due to the PI-1 tube pull results, Zion began questioning the leak-tightness and structural integrity regarding the 26 existing sleeves that have been left in service in Zion Unit

-2 with weld zone indications. These 26 sleeves are distributed amongst only 2 steam generators, A and C and are as follows:

Unit-2 Steam Generator # Indications A 18 C 8

2. IDENTIFICATION OF SAFETY FUNCTIONS

a. Direct Functions:

Does the failed or degraded component perform any Direct Function as defined by any of the following:

YES NO

[ ] UX] Does the component actuate upon receipt of, or initiate an RPS or an ESF actuation signal?

[ ] UX] Does the component supply or receive power from an ESF bus?

[ I K[X]Is the component part of a flow path of an ESF system or ESF support system?

[XI [ ] Is the component used to maintain containment integrity or establish Phase A or Phase B containment isolation?

[ ] [X] Is the component used to provide separation or isolation between redundant Safety Trains, or Safety to non-Safety related ties?

[ I [X Is the component used to control reactivity?

APPENDIX A

[XI [ Is the component used to control, provide a barrier for, or provide indication of a release of radioactivity?

X] [] Does the component provide nuclear residual heat removal?

]

I X] Does the component provide suppression capability, a physical barrier for, or indication

.of, a fire in the Auxiliary Building, Fuel Handling Building, Turbine Building, Containment or Control Room?

LX] [ ] Is the component part of, or maintain the integrity of, the RCS pressure boundary?

b. Support Functions:

Does the failed or degraded component provide a Support Function, as described by any of the following, to a component that is described in the Technical Specifications or performs a Direct Function per step 2.a?

YES NO I ] ] Does the component provide indication (i.e. amp meter, status light, etc.) that can be used to determine if a component is (or is not) operating correctly?

[ I ] ] Does the component provide control functions for a component?

[X] Does the component provide the motive force (electrical or mechanical) for a component?

EX] [] Does the component provide cooling for a component?

[] X] Does the component provide lubrication for a component?

[ I [XI Does the component provide area ventilation for a component?

• 0 APPENDIX A

2. IDENTIFICATION OF SAFETY FUNCTIONS (Continued)

I I ] ] Does the component provide seal water for a component?

[I )[X] Does the component provide structural support for or maintain the structural integrity for a component?

[ ] K[X]Does the component maintain the status of a component such that it can perform its safety functions when required? '

[XI [ ] Is the component identified as Safety Related, EQ or Appendix R? (Refer to the "Zion Station Unified Component List" and the "Appendix R List")

List the components that the failed/degraded component provides support for:

Steam Generators A, C 2RC-100, 200

c. Subsequent Failures Is there an existing deficiency or condition, as described by any of the following, that is associated with one or more components that are described in Technical Specifications or that performs Safety Functions?

YES NO

[ [XI Is there foreign material or loose parts in an unknown or unwanted location?

I 1 X] Is there a structural component (e.g., pipe hanger, motor mount, flange bolt, etc.) that is missing or deficient?

[X] Is there information, performance values or data which indicates abnormal operation?

List the associated component(s) that could be affected by any of the above (Refer to steps 2.a and 2.b for identification of Safety Functions of components that may be affected):

APPENDIX A Associated Components: None

3. INITIAL OPERABILITY ASSESSMENT:

a. List all Safety Functions for the affected component(s) identified by steps 2.a, 2.b and 2.c.

The safety function of the steam generators (S/Gs) is to serve as a boundary to preclude leakage between the radioactive primary side and the non radioactive secondary side of the unit and the atmosphere. The tubes also transfer decay heat and sensible heat from the Reactor Coolant System during the initial phases of safety injection until the RHR system can be placed into cooperation for long term cooling. One of the four S/Gs is capable of providing sufficient heat removal capacity to remove core decay heat after a normal shutdown.

Safety Related: Yes EQ: No APPENDIX R: No Reg. Guide 1.97 N/A

[ ] NO SAFETY FUNCTIONS IDENTIFIED

b. Is there reasonable assurance that the affected components are capable of performing all their required Safety Functions at this time?

(N/A if no Safety Functions identified in step 3.a.)

[ ] NO Declare the component INOPERABLE.

GO TO STEP 4

[ N/A NO SAFETY FUNCTIONS IDENTIFIED.

GO TO STEP 4

[X] YES Explain:

Based upon the following discussion, Maintenance Engineering at Zion and ComEd Steam Generator Group has determined that the continued operation of the Unit 2 steam generators (A and C) is safe and does not pose a risk to the health and safety of the public.

Subsequent to ComEd becoming aware of the Combustion Engineering sleeve issue at PI-1 and the preliminary

APPENDIX A determinations from the examination of the 5 sleeved tubes pulled for metallurgical examination, an extensive review of the Zion Unit 2 inspection results of, the CE sleeves left in service with weld zone indications, was performed. This evaluation, a joint effort by ComEd and Combustion Engineering, was done to determine if similar indications are present in Zion Unit 2. The review indicated that 26 tubes existed in Unit 2 which had some type of weld zone indication. A listing of these tubes is identified below:

Steam Generator A C row column row column 11 20 2 47 17 20 3 22 5 21 3 33 7 22 5 35 11 22 7 30 6 23 7 .46 9 25 12 52 13 25 7 47 19 26 13 27 10 28 11 29 24 29 15 31 29 31 8 34 14 34 12 71 Based upon Zion's review of the documented inspections records, Zion believes the extent of the issue is limited to the 26 tubes listed above.

To address all of the sleeves installed at Zion Station, the following describes the inspection process at Zion Unit 2.

After the initial installation of a CE sleeve, a number of examinations are performed to demonstrate the installation requirements are met per the CE Final Report CEN-331-P, Revision 1-P, dated June 3, 1986, "Zion Units 1 and 2 Steam Generator Tube Repair Using Leak Tight Sleeves." These

APPENDIX A examinations include a visual examination, an ultrasonic examination and an eddy current examination.

NDE Inspections for Installed Sleeves

1. Visual examination of the upper sleeve weld (100% of the sleeves in Zion Unit 2 have been visually examined and have met the inspection criteria described below).

Visual examination of the upper sleeve weld interior diameter is performed by CE after completion of the weld and before ultrasonic testing in accordance with the sleeve installation procedures. The weld is considered visually acceptable if it is found to be free of imperfections that could be detrimental to the integrity of the weld.

Detrimental imperfections are blow holes at the lower edge of the upper weld, blow holes extending through the sleeve into the tube, porosity, incomplete or partial weld and lack of fusion. Nondetrimental qualities are weld roughness, down slope weld tail and weld ripple.

If in subsequent eddy current inspections ambiguous indications are identified additional visual inspections are performed to further evaluate the indications.

2. Ultrasonic examination of upper sleeve weld (100% of the sleeves in Zion Unit 2 have been ultrasonically examined upon installation).

An ultrasonic examination is used to confirm fusion of the sleeve to the parent tube after welding. A minimum of three 360 degree scans are performed, each covering approximately 0.020 inches of weld height. If continuous 360 degree fusion without a non-fusion leak path is demonstrated the weld is acceptable.

3. Eddy current examination using the +Point probe (or magnetic bias +Point probe) has been performed on 100% of the sleeves in operation at Zion Unit 2.

Any indications which were identified during the initial eddy current examination as circumferential in nature, would be required to be removed from service. Eddy current indications that were within the weld zone and not

0 0 APPENDIX A identified as being circumferential in nature were classified as weld zone indication and remain in service.

Regarding the 26 Sleeves in question, a review of the Technical Specification was conducted. Two sections of the Technical Specification will be discussed.

Section 4.3.1.B.4.A.6.a,b,c A review of this section, indicates that TS 4.3.1.B.4.A.6.a warrants discussion because the area in the upper weld joint is the area in which the indications are located. This section states the following:

Combustion Engineering Sleeves

a. for the area in the upper weld joint, any imperfection produced by degradation shall be plugged unless it can be clearly demonstrated by a qualified NDE technique that the imperfection is < 33% of the nominal wall thickness for I.D. imperfections or < 40% thickness of the tube for O.D. imperfections.

This section of the technical specifications define the repair criteria for Combustion Engineering Sleeves.

Degradation is defined in the Zion Technical Specification, Section 4.3.1.B.4.A.2, as "service induced cracking, wastage, wear or general corrosion occurring on either inside or outside of a tube."

Based upon the preliminary results from the PI-1 pulled sleeved tubes, no evidence has been provided by CE which indicates that the PI-1.findings are service induced. In fact on the contrary, the PI-1 data indicates that:

-no service induced degradation is present,

-no degradation of parent tube,

-weld indications are process induced,

-no intergranular nature,

-structural integrity is adequate, and

-no growth since previous inspection, and

-minor leakage at MSLB of worst case condition.

APPENDIX A It is assumed that since potential Zion findings would mirror PI-1, and therefore are not service induced, the referenced technical specification sections would not apply.

Another section which warrants discussion is TS Section 4.3.1.B.4.A.10. This section states:

"Repaired Tube means a tube that has undergone a process that re-establishes its serviceability. The sleeving process utilized shall be one of the following:

a. The Combustion Engineering welded sleeve process as described in Report CEN-331-P."

Regarding this, Zion believes that the process used for its sleeve installations was/is consistent with the referenced report, although as implemented at Zion it may not have been performed consistent with Zion's expectation. This deficiency does not negate the continuing existence of the applicability of the topical as presently worded. Therefore, this section of the Technical Specification does not apply to this situation.

Based on the previous discussion, Zion examined which criteria applies to Zion Unit 2 if it assumes that the Prairie Island findings exist. Absent of applicable flaw related Technical Specification provisions, the remaining operability criteria would be the following:

1. The steam generator primary to secondary leak limits as identified in the Technical Specifications.

2. Regulatory Guide 1.121 structural guidelines

3. 10CFR100 and GDC-19 dose limits not exceeded.

Criteria #1 Present Zion Technical Specification limits the primary to secondary leakage to 1 gpm total or 500 gpd for any one steam generator (TS 3.3.3.E). To ensure this criteria is maintained, Zion would take action prior to a deficient sleeve reaching it's maximum leakage potential. Zion Unit 2 currently does not have any measurable primary to secondary leakage.

APPENDIX A Criteria #2 Based on preliminary results of the PI-1 sleeved tube pull examinations, all indications at PI-1 are within the Regulatory Guide 1.121 limits. Preliminary calculations performed by CE determined that an average weld height of 0.027 inch is required to meet ASME code and 0.012 inch minimum wall thickness over 360 degrees to meet Reg. Guide requirements.

Based on preliminary review by Rockridge Inc. of the eddy current data of the 26 sleeves identified as having weld zone indications in Zion Unit 2, the PI-1 circumferential indications appear to be much more severe. Some of the volumetric type indications identified at Zion Unit 2 appear slightly larger than the 1 volumetric indication pulled from PI-1 but are still believed to be within structural limits based on laboratory results which have not identified indications within the pressure boundary of this nature not to be more than 10% of wall loss.

Criteria #3 Preliminary calculations have determined that if a 360 degrees cracked sleeve condition were to develop, the maximum leakage obtained at MSLB would be 1.4 gpm.

ComEd does not believe that a guillotine break of a steam generator sleeved tube is credible due to the structural integrity of the parent tube not being degraded in the sleeve weld area. Additionally, it is not credible that both the A and C steam generators could develop a MSLB simultaneously; therefore, based on there being 18 sleeves with weld zone indications in the A steam generator and 8 in the C steam generator, the worst case scenario is accident leakage value of 1.4 gpm for each of the 18 sleeves with weld zone indications in the "A" steam generator.

By multiply the 18 sleeves times a worst case accident leakage rate of 1.4 gpm a total leakage rate of 25.2 gpm can be conservatively calculated. Based on the calculated allowable leak rate determined in May of 1995 (T. Simpkin letter to NRC dated May 17, 1995)for the Zion Unit 1 steam generator NOED. A 5.31 leakrate

APPENDIX A with a RCS activity level of 1 microcurie/gram dose equivalent 1-131 is within a small fraction of 10CFR100 dose limits. To assure MSLB is within limits, the dose equivalent 1-131 will be administratively lowered to 0.2 microcuries per gram.

Therefore, based on the indications being installation induced and not associated with service induced degradation and due to the 3 criteria discussed above being achieved, Zion Station is confident that Unit 2 can safely and reliably operate without any increase in risk to the health and safety of the public.

4. DISPOSITION:

a. [ ] NO SAFETY FUNCTIONS IDENTIFIED Based on the, [ ] ZODM, [ ] assessment in step 2, no Safety Functions have been identified for the affected component(s). An Operability Issue does NOT exist.

b. [X] SAFETY FUNCTIONS IDENTIFIED

[X] Component OPERABLE.

Based on the, [ ] ZODM, [X] evaluation in steps 2 and 3, there is reasonable assurance that the affected component(s) are capable of performing their Safety Functions.

[X] An Operability Issue exists, Appendix B initiated.

An Operability Issue does NOT exist Component INOPERABLE.

Based on the, [ ] ZODM, [ ] evaluation in step 3, degradation in the ability of the affected component to perform its Safety Functions has been identified.

0 APPENDIX A

c. APPROVAL Prepared By: T. M. Cook x-3172 Date -: 2'.

~Engi eer f Approved By: R. 7Sk gird x 2192 Date_3__

Engineering Supv.

5. OPERATING DEPARTMENT REVIEW AND APPROVAL:

Equipment is INOPERABLE and requires a PT-14. GO TO PT 14 and attach a copy of this form. Forward this form to System Engineering.

Equipment is INOPERABLE and requires a PT-14E, or an Operability Issue exists that requires Shift personnel awareness. GO TO PT-14E and attach a copy of this form.

Forward this form to System Engineering.

[4 No action required. Forward this form to System Engineering.

'LSS/Operating Eng. Date

APPENDIX B ZODM-0 Rev. 7 OPERABILITY ISSUE FORM Assessment # 96-01283 Rev. 0 DESCRIPTION

SUMMARY

/DISPOSITION:

This Appendix B Operability Assessment includes new information received from Combustion Engineering in their report, CEN-628-P, Rev. 00-P, recieved, March 25, 1996, dated March 1996, entitled, "Verification of the Structural Integrity of the ABB CENO Steam Generator Welded Sleeve". Based on this new information, some information included in the Appendix A, Initial Operability Assessment, dated March 7, 1996, has been enhanced to clarify the relationship of this issue with respect to the current Zion Technical Specification and the guidance provided in Generic Letter 91-18 regarding operability. It also will address that the overall safety significance of this issue is minimal.

Component(s) Affected:Unit 2 Steam Generator Upper Sleeve Welds with Weld Zone Indications These indications are found in the A and C steam generators Failure Description Summary:

This Operability Assessment stems from the results of recent inspections that have occurred at Prairie Island Unit-I (PI-1) concerning Combustion Engineering (CE) TIG welded sleeves.

During the PI-I inspection that occurred in the first quarter of 1996, eddy current examinations of both in-service and new sleeves in the No. 12 steam generator were performed using the

+Pointm coil probe. Both circumferential and volumetric indications were identified at the upper sleeve weld. This weld serves as the pressure boundary interface for the repaired tube.

Because circumferential indications were identified on the upper sleeve welds at PI-1, and because it was not clear that the sleeves would maintain requisite structural integrity, the tubes were plugged.

PI-1 also identified 51 tubes which had only volumetric indications. Of the 51 tubes, 14 were plugged based on a determination that they were within the pressure boundary portion of the weld and 1 tube was removed for metallurgical examination. Therefore, a total of 15 tubes were removed from service for volumetric indications.

Four tubes with circumferential indications and one tube with a volumetric indication were physically removed from PI-1. The objectives of the sleeved tube removal examination program were to: (1)identify the physical condition(s) present in the sleeve joints which have resulted in the eddy current test indication observed, (2)determine whether these conditions are a result of installation anomalies or of service induced degradation and provide sufficient characterization of the condition(s) as to determine the structural integrity. of the sleeve, and (3)if installation induced, identify the portion of the process contributing to the condition or if service induced, identify the degradation mechanism and the causative environmental factors.

The PI-I pulled tube examination results have shown that all 5 tubes exhibited oxide film inclusions and sleeve OD suckback at the upper or lower edge of the weld. Due to the PI-1 tube pull results, Zion began investigating the leak-tightness and structural integrity regarding the 26 existing sleeves that have been left in service in Zion Unit 2 with weld zone indications.

I

S APPENDIX B ZODM-0 Rev. 7 These 26 sleeves are distributed among the 2 steam generators, A and C as shown below:

Ulnit-2 Steam Generator ## Indications Indications Unit-2 SteamAGenerator 18 C 8 As a conservative measure, to allow for Unit 1 startup prior to resolution of this issue, all 43 sleeved tubes with volumetric indications that were left in service in past outages, were plugged in the recent maintenance outage, (March 1996).

DISPOSITION: [X] OPERABLE []INOPERABLE ATTACHMENTS:

Initial Operability Assessment [X] APPENDIX A (Required)

Operability Issue Action Plan: [ I ATTACHMENT 1 [X] NONE Safety Function Evaluations: [X] AS LISTED IN ATTACHMENT 2 []NONE Compensatory Actions Required: [X] AS LISTED IN ATTACHMENT 3 []NONE Corrective Actions Required: [X] AS LISTED IN ATTACHMENT 4 []NONE APPROVALS:

Date ~2 Engineering Supervisor\

Date____

Operating Engineer T wou.

ZODM Review Required: [] YES, Initiate OFR

[X] NO COMPENSATORY/CORRECTIVE ACTIONS COMPLETED:

(N/A if no Compensatory and/or Corrective Actions required)

Date Regulatory Assurance Supv Date Engineering Supv 2

APPENDIX B ZODM-0 Rev. 7 EVALUATION OF OPERABILITY ISSUE Based on the Safety Functions identified in Appendix A, "Initial Operability Assessment", make an evaluation of how the existing degraded component or condition affects the component(s) that perform those Safety Functions. The statements below apply to the component that performs the Safety Functions.

The items below identified as confirmed are based on the detailed review as documented in the CE report issued to ComEd Zion Station, dated March 1996, entitled, "Verification of the Structural Integrity of the ABB CENO Steam Generator Welded Sleeve" CONFIRMED POTENTIAL NO

a. [XI [I [] There is a structural defect or deficiency on the body of the component, supporting structure or associated sealing surfaces that threatens the integrity of the component.

Visual Insp. Performed By:

(N/A if visual inspection was not performed.)

Date: Time:

b. [XI [] [] There is a condition of the component that results a loss of functional capability.

c. [] [] [X] There is a condition that results in the component not meeting design requirements stated in the UFSAR.

d. [] [] [X] There is a condition that results in the component not conforming to applicable codes or standards specified in the UFSAR.

e. [] [] [X] There is operating experience, information or engineering reviews that demonstrate a design inadequacy.

f. [ ] [] [X] There is an existing, unanalyzed condition or accident.

g. [X] [] [] There is a condition of the component that results in a loss of quality or reliability.

[X] At least one of the above items are CONFIRMED. An actual deficiency that may apply to the component's Safety Function(s) has been identified. Perform an Operability Assessment per Attachment 2 for each CONFIRMED deficiency.

OR S At least one of the above Items are POTENTIAL. A potential deficiency that may apply to the component's Safety Function(s) has been identified. Form an Operability Issue Action Plan per Attachment 1 for each potential deficiency.

OR 3

0 APPENDIX B S ZODM-0 Rev. 7

.7

[ ] ALL items answered NO. No degradation of Safety Function(s) identified. No Operability Issue exists.

2. DISPOSITION OF OPERABILITY ISSUES Based on the evaluation presented in Appendix A and section 1:

[] No Safety Functions have been identified. No Operability Issue exists.

Safety Functions have been identified, however no degradation of Safety Functions exists. No Operability Issue exists.

A potential degraded condition that may affect the component's Safety Functions has been identified. An Action Plan to dispose of the Operability Issue has been completed per Attachment 1.

[XI A confirmed degraded condition that may affect the component's Safety Functions has been identified. An Operability Assessment shall be initiated per Attachment 2.

[] The component is INOPERABLE.

Evaluation Performed By:

-Engineer Date Time Approved By:. /3AziL (./ /S723 Engineering Supv. U' ate Time 4

APPENDIX B ZODM-0 Rev. 7 ATTACHMENT 2 SAFETY FUNCTION EVALUATION SHEET Safety Function Item No 3a of Appendix A Confirmed Deficiency No. labg of Appendix B Describe the effect of the failure, defect, degraded or non-conforming condition on the specified safety function:

The safety function of the sleeve to tube upper weld is to prevent leakage during normal and postulated accident conditions. The failure of the weld could allow minimal leakage from the primary side to secondary side.

Disposition Of Safety Function: [X] OPERABLE [ ] INOPERABLE Basis for disposition:

Currently, Zion Unit 2 has no detectable primary to secondary leakage. Additionally, based on the referenced report, the maximum potential leakage that would occur if all sleeved tubes of concern (sleeved tubes with indications that could potentially affect the pressure boundary as described in the report) would leak in one of the steam generators during a main steam line break would be 0.128 gpm. This leakage value is significantly below the leakrate of 5.31 gpm that would allow Zion to be within a small fraction of the 10CFR100 dose limits. Finally, all sleeved tubes in question meet the structural requirements of the ASME code.

Based upon the above and the following discussion, Maintenance Engineering at Zion Station and the ComEd Steam Generator and RPV Project Team has determined that the continued operation of the Unit 2 steam generators (A and C) is safe and does not pose an increased risk to the health and safety of the public.

This disposition is based on the efforts by Combustion Engineering, utility representatives (Prairie Island, Arkansas Nuclear One, Ginna, Kewaunee) and ComEd, which resulted in the report entitled, "Verification of the Structural Integrity of the ABB CENO Steam Generator Welded Sleeve". This report was issued to ComEd on March 25, 1996, and is included as part of this Operability Assessment as Attachment 1.

Subsequent to ComEd becoming aware of the Combustion Engineering sleeve issue at PI-1 and the determinations from the examination of the 5 sleeved tubes pulled for metallurgical examination, an extensive review of the Zion Unit 2 inspection results of the CE sleeves left in service with weld zone indications was performed. This evaluation, a joint effort by ComEd and Combustion Engineering, was performed to determine if similar indications are present in Zion Unit 2. The review indicated that 26 tubes existed in Unit 2 which had some type of weld zone indication.

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APPENDIX B ZODM-O Rev. 7 A listing of these tubes is identified below:

Steam Generator A C Row Coluimn Row Row Coluumn Colu n Colu n 11 20 2 47 17 20 3 22 5 21 3 33 7 22 5 35 11 22 7 30 6 23 7 46 9 25 12 52 13 25 7 47 19 26 13 27 10 28 11 29 24 29 15 31 29 31 8 34 14 34 12 71 Based upon Zion's review of +Point inspection results and review of the documented inspection records, Zion believes the extent of the issue is limited to the 26 tubes listed above. It is our belief that the combination of installation ultrasonic examination and the +Point examination provide adequate assurance to identify all tubes with significant oxide films and inclusions. This is based upon the results of the Prairie Island sleeve pull examination, which has shown that oxide inclusions which are, in some cases, difficult to detect with the ultrasonic examination, always coexist with other inclusions which were detected by the +Point probe.

A. NDE Inspections for Installed Sleeves Described below are the inspections performed on the CE sleeves after installation.

After the initial installation of a CE sleeve, a number of examinations are performed to demonstrate the installation requirements are met per the CE Final Report CEN-33 1-P, Revision 1-P, dated June 3, 1986, "Zion Units 1 and 2 Steam Generator Tube Repair Using Leak Tight Sleeves." These examinations include, an ultrasonic examination, an eddy current examination and a visual examination.

1. 100% Ultrasonic examination of upper sleeve weld is required upon installation.

An ultrasonic examination, using an immersion technique with demineralized water as a couplant, is used to confirm fusion of the sleeve to the parent tube after welding. A minimum of three (3), 360 degree scans, are performed, each covering approximately 0.020 inches of weld height. If continuous 360 degree fusion without a non-fusion leak path is demonstrated, the weld is acceptable.

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APPENDIX B ZODM-O Rev. 7

2. Eddy current examination as indicated in CEN 33 1-P, Revision 1-P, specifies the use of the cross wound probe for baseline inspection. Use of the +Point probe (or magnetic bias plus point probe), which has been demonstrated to be more sensitive to indications which occur in sleeves, was performed on 100% of the sleeves in operation at Zion Unit 2, during the last refueling outage.

Eddy current indications that were within the weld zone were classified as a weld zone indication and remained in service based upon meeting the acceptance criteria of the ultrasonic and visual inspections.

3. 100% of the sleeves in Zion Unit 2 have been visually examined and have met the acceptance criteria described below.

Visual examination of the upper sleeve weld interior diameter is performed by CE after completion of the weld and before ultrasonic testing in accordance with the sleeve installation procedures. The weld is considered visually acceptable if it is found to be free of imperfections that could be detrimental to the integrity of the weld.

Detrimental imperfections are blow holes at the lower edge of the upper weld, blow holes extending through the sleeve into the tube, porosity, incomplete or partial weld and lack of fusion. Non-detrimental qualities are weld roughness, down slope weld tail and weld ripple. If in subsequent eddy current inspections ambiguous indications are identified, additional visual inspections are performed to further evaluate the indications.

B. Technical Specification and Licensing Basis Applicability Review In light of the Prairie Island experience with CE sleeve and the possibility that similar indications may exist in the 26 tubes left in-service, a review of the Technical Specifications and the licensing bases was conducted. An evaluation of the review of the Technical Specifications has determined that the Technical Specifications do not apply, and that the sleeve inspections and installation process were performed in accordance with the licensing bases. At the time the sleeving process was licensed, using available technology, the sleeving process qualification was designed and implemented to preclude the weld zone indications from being put in service.

The Topical Report, CEN-33 1-P, "Zion Units 1 and 2 Steam Generator Tube Repair Using Leak Tight Sleeves" was reviewed and approved by the NRC and forms the licensing bases. The Topical Report describes that the objectives of installing sleeves in the steam generator tubes are twofold.

• The sleeve must maintain structural integrity of the steam generator tube during normal operating and postulated accident conditions.

• The sleeve must prevent leakage in the event of a through wall flaw in the steam generator tube.

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APPENDIX B ZODM-0 Rev. 7 To meet these objectives, certain inspections (UT, Visual and Eddy Current) were specified in the Topical Report to ensure that the welds meet these design requirements. All upper welds were examined with UT. On a periodic basis , or if any abnormal conditions were suspected, a visual examination was performed. An eddy current inspection was used to establish baseline data and was specified as part of the periodic in-service inspection of the steam generator tubing. Specific details are as follows:

• The objective of the eddy current examination was to establish baseline data on the primary pressure boundary of the sleeve-tube assembly. The examination was developed to detect ASME sized flaws (CEN 33 1-P, Section 5.2.1) in the parent tube and/or sleeve in any region of the sleeve-tube assembly with a single pass of an eddy current coil. The Topical Report requirement is to perform the eddy current testing with a cross wound probe.

• Ultrasonic techniques were employed to confirm the presence of sleeve-tube weld fusion. In actual tests, a lack of fusion 0.012 inches wide had been reliably detected.

• Visual examination was performed on the upper welds to support UT and performed on the lower welds to determine their integrity and acceptance. The inspections are performed to ascertain the mechanical and structural condition of each weld. Critical conditions which are checked include weld width, weld completeness and the absence of visible indications, such as cracks, pits, blow holes, bum throughs, etc. The weld acceptance was based on the absence of cracks or other visible imperfections which would be detrimental to the integrity of the weld. During the examination, any area which contained imperfections was examined more closely.

The root cause of the anomalies detected at Prairie Island has been determined to be inadequate cleaning of the parent tube. The necessity to perform adequate cleaning prior to sleeve installation is addressed in the Topical Report. The cleaning process, as it was qualified, was determined to be adequate. However, subsequent modifications to the cleaning process and equipment resulted in a condition not expected and not readily detected by UT techniques applied at the time of installation. Recent eddy current technology advancement, such as development of the +Point technique, has provided the capability of detecting the anomalies observed at Prairie Island.

The surveillance requirements for Zion Unit 2 were performed in accordance with the Technical Specifications and Topical Report and any anomalies were dispositioned accordingly. Based on the inspection techniques available when the sleeves were installed, the sleeves left in service in Zion 2 were dispositioned as acceptable and installed in accordance with the plants licensing bases.

The Technical Specifications address the in-service inspection and repair requirements, but do not provide guidance on installation acceptance criteria. The inspections performed met the surveillance requirements as outlined in the Technical Specifications. Based upon this discussion, it is concluded that these anomalies are not addressed in the Technical Specifications, constitutes a degraded condition, and therefore, the guidance in Generic Letter (GL) 91-18 applies.

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APPENDIX B ZODM-0 Rev. 7 C. Resolution of De2raded Condition As part of the GL 91-18 evaluation, Zion examined which criteria applies to Zion Unit 2 assuming that the Prairie Island findings are present. Absent Technical Specification provisions, the operability criteria have been established as follows:

1. Operational Leakage

2. Structural Integrity

3. Accident Leakage Criteria #1 - Operational Leakage Present Zion Technical Specification limits the primary to secondary leakage to I gpm total or 500 gpd for any one steam generator (TS 3.3.3.E). To ensure this criteria is maintained, Zion would take action based on a more conservative administrative limit specified in the AOP 1.2, "Steam Generator Tube Leak", of 300 gpd. Zion Unit 2, currently does not have any measurable primary to secondary leakage.

A compensatory measure for the current operating cycle is to reduce the primary to secondary leakage limit. Zion Unit 2 will reduce its administrative primary to secondary leakage limit from steam generator tubes from 300 gpd for any one steam generator (AOP-1.2, Step 4e) to 150 gpd for any one steam generator. This new steam generator leakage limit is consistent with the EPRI Report 104788, "PWR Primary to Secondary Leak Guidelines." The reduction in this limit enhances the defense in depth concept and provides additional assurance against abnormal leakage and tube rupture at normal and faulted loads.

Criteria #2 - Structural Integrity Calculations performed by CE determined that an average minimum weld height of 0.019 inch is required to meet ASME code and Reg. Guide 1.121 requirements for Zion Unit 2. Based on the PI-I sleeved tube pull examinations, all indications at PI-1, are within the Regulatory Guide 1.121 limits.

Based upon testing CE has performed and documented in their report, all laboratory flawed tube specimens currently in the sleeve evaluation program meet ASME and Reg. Guide 1.121 Structural requirements.

Sleeves were initially addressed in the 1989 Edition, 1989 Addenda of ASME Section XI. Zion is committed to the 1989 Edition of ASME Section XI, no addenda. The potentially degraded sleeve joints were installed and examined in accordance with the Topical Report, which was developed prior to Section XI addressing sleeves.

Utilizing the 1989 Addenda for guidance in the examination of fusion welded sleeves, Paragraph IWA-4423.4 states that the "welded sleeve attachment shall be examined to confirm that the attachment is in the correct location and conforms to the Construction Code and Owner's Requirements." The potentially degraded sleeve joints also comply with this requirement, in that the Construction Code (ASME Section III 1965 Edition with the 1967 Addenda) does not address examination requirements for sleeves, and the Technical Specifications and Topical Report 9

APPENDIX B ZODM-0 Rev. 7 requirements constitute "Owner's Requirements." As discussed previously, the examination requirements exceeded those described in the Topical Report.

Combustion Engineering and Rock Ridge has performed a review of the eddy current + Point data for the 26 sleeves identified as having weld zone indications in Zion Unit 2. The objective of the review was to determine where the indications are located in relation to the weld centerline, (i.e. inside or outside pressure boundary), and determine if they are bounded by the PI-I sleeve pull indications.

The results of the review determined the following:

VOL -- Volumetric Indication PCI -- Possible Circumferential Indication C/L -- Centerline S/G VOL VOL PCI PCI Above Below Above Below Weld C/L Weld C/L Weld C/L Weld C./L A 6 5 4 3 C 3 4 1 0 Using the Prairie Island analysis criteria, a range of volumetric (VOL) and possible circumferential indications (PCI) were called in the review. The locations of the VOL and PCI signals ranged from above to below the weld centerline. For Zion Station, a direct comparison with Prairie Island data was possible by normalizing the amplitude response to a common calibration flaw. For these tubes, the amplitude and arc length range of signals are bounded by the Prairie Island PCI results for their plugged and inservice tubes. A direct comparison of VOL amplitude calls was not possible because of variability of geometric signals superimposed on the VOL signal.

The ultrasonic data threshold C scans were reviewed for the 26 tubes. All tubes satisfy the 360 degree fusion criteria and four tubes had short local thin sections in the weld, but all welds are within the requirements to satisfy the Reg. Guide 1.121.

One additional tube called NDD in the original inspection was also re-evaluated by Rock Ridge as a small amplitude VOL below the weld centerline. Because of this additional call of a previous NDD tube, this tube was compared to a number of laboratory samples with volumetric indications in the weld that were confirmed by metallography. The purpose of this additional review was to assess the size and detection limit of these type of signals as well as assess whether additional analysis was required to determine if other NDD calls were suspect. An amplitude correlation curve was developed from laboratory samples using the vertical voltage component of the signal for this type of flaw and this particular tube was estimated at 10-15% throughwall in the sleeve. The existence of isolated shallow imperfections does not warrant reanalysis of previous data.

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APPENDIX B ZODM-0 Rev. 7 Criteria #3 - Accident Leakage CE has reviewed the ultrasonic test data for the 26 sleeves identified with weld zone identifications and has determined that they have all met installation requirements. This strengthens our belief that the sleeves are leak tight. In the event that they are not leak tight, the following evaluation was performed:

• Testing performed by CE on actual flawed sleeve specimens with 3600 non-bonded areas have been shown to leak at a rate of 0.016 gpm at 2700 psid, and room temperature conditions. (Zion's Main Steam Line Break (MSLB) differential pressure is 2350 psid.)

This leakage rates is the result of 16 tests performed on tubes with a variety of non-bonded areas from 5 degrees to 360 degrees. These results bound earlier testing performed for Ringhals (1986) and Ginna (1995) which indicated a leakage value of 8.8 x 10-6 gpm and 0.0013 gpm respectively. The nature of the inclusions resulting in non-bonded areas in the weld zone, have been shown through laboratory testing and the PI-I tube pull results, not to propagate in service. Therefore these actual tests results indicate a bounding leakage value of 0.016 gpm per sleeve with a weld zone indication.

• Aside from the 0.016 gpm being the bounding leakage value for the non-bonded condition, it is concluded that this value is also bounding for the most limiting weld inclusions observed.

The circumferential indications identified by eddy current examination and characterized by metallurgical analysis retain sufficient weld cross sectional area to prevent axial separation at the circumferential inclusions. The radial inclusions have been shown to be less than 0.001 inch thick. Thus, for the weld inclusion, the leakage value of 0.016 gpm is bounding.

ComEd does not believe that a guillotine break of a steam generator sleeved tube is credible due to the structural integrity of the parent tube not being degraded in the sleeve weld area.

Additionally, it is not credible that both the A and C steam generators could develop a MSLB simultaneously. Therefore, based on there being 12 sleeves with weld zone indications (PCI or VOL) that are classified as being below the centerline of the weld, 8 are in the A Steam Generator and 4 are in the C Steam Generator. The worst case scenario is an accident leakage value of 0.016 gpm for each of the 8 sleeves in the A Steam Generator.

By multiplying the 8 sleeves by the worst case accident leakage rate of 0.016 gpm, a total leakage rate of 0.128 gpm could occur. This value is small compared to the calculated allowable leak rate determined in May of 1995 (T. Simpkin letter to NRC dated May 17, 1995)for the Zion Unit 1 steam generator NOED. This calculation determined that a 5.31 gpm leakrate with a RCS activity level of 1 microcurie/gram dose equivalent 1-131 is equivalent to a small fraction of 10CFR100 dose limits.

Calculations based on Zion Station probabilistic risk assessment (PRA) indicate that a Main Steam Line Break has a probability of occurrence of only 5.5 x 106 during the next 6 months.

For comparison, the steam break initiating event frequency in the Modified Zion Individual Plant Examination was 1.8 x 10-3 /yr and yielded a core damage frequency of only 5.1 x 10-10/yr.

Therefore, even given a steam break (initiating event frequency = 1.0 rather than 1.8 x 10-3) the resulting probability of core damage is approximately 2.8 x 10-. This is a very low probability and is non-risk significant.

In the Appendix A, Initial Operability Assessment, the Dose Equivalent Iodine (DEI) limit in the Technical Specifications was reduced to a limit of 0.2 microcuries/gram due to the analytical leakage postulated to be 1.4 gpm. Due to the test leakage results being significantly smaller, the DEI will be placed back to it's normal Technical Specification limit of 1.0 microcuries/gram.

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S APPENDIX B 0 ZODM-0 Rev. 7 CONCLUSIONS Therefore, based on the indications being installation induced and not associated with service induced degradation, the low postualted accident leakage and the ability to meet the requirements of the ASME Code and Regulatory Guide 1.121, Zion Station is confident that Unit 2 can safely and reliably operate without any increase in risk to the health and safety of the public.

Compensatory Action Required To Ensure Operability:

See Attachment 3 Corrective Action To Restore To Full Qualification:

See Attachment 4 12

APPENDIX B ZODM-0 Rev. 7 ATTACHMENT 3 COMPENSATORY ACTION ITEM LIST Assessment # 96-01283 Rev. 0 Listed below are compensatory or mitigating conditions that are required to support operability:

Compensatory Action #1:

Administratively reduce the allowable primary to secondary leakage limit from steam generator tubes from 300 gpd for any one steam generator (AOP-1.2, Step 4e) to 150 gpd per steam generator. This limit will be in effect for Unit-2 for the remainder of the operating cycle.

Responsible Dept./Supv. Operating Dept. /W. Demo Action Due Date: 3/26/96 NTS: n/a Compensatory Action #2:

Put standing order into affect which will make any work on the 2R-PR15 (gas monitor) and 2R-019 (blowdown monitor) a Priority 1 work request Responsible Dept./Supv. Operating Dept. /W. Demo Action Due Date: 3/26/96 NTS: n/a Compensatory Action #3:

The portable Unit-2 N-16 monitor will be used as an additional means to monitor the 2A or 2C main steam line for primary to secondary leakage Responsible Dept./Supv. Chemistry/ B. Schramer Action Due Date: completed NTS: n/a 13

APPENDIX B ZODM-0 Rev. 7 ATTACHMENT 4 CORRECTIVE ACTION ITEM LIST Assessment # 96-01283 Rev. 0 Corrective Action #1:

A qualified Ultrasonic testing method for sleeves with Weld Zone Indications will be developed by Combustion Engineering. This process will be available and used during the next Unit 2 refueling outage scheduled for the September of 1996. This enhanced UT process will be used on all sleeves that have Weld Zone Indications that are evident by the +Point Probe.

Responsible Dept./Supv. Maintenance Engineering/R. Lane Action Due Date: 9/1/96 NTS: 304-140-9601283-01 Corrective Action #2:

All 26 sleeves with Weld Zone Indications will be inspected in the next Unit 2 refueling outage using the enhanced UT process. After this inspection is complete and based on the acceptance criteria, it will be determined whether or not to leave these sleeves in service.

Responsible Dept./Supv. Maintenance Engineering/R. Lane Action Due Date: 11/1/96 NTS: 304-140-9601283-02 14