ML20249A875

Forwards Request for Addl Info Re Proposed Amend to Redefine Parent Tube Pressure Boundary for Westinghouse Mechanical Hybrid Expansion Joint SG Tube Sleeves,Submitted by Util

ML20249A875
Person / Time
Site:	Kewaunee
Issue date:	06/16/1998
From:	Long W NRC (Affiliation Not Assigned)
To:	Marchi M WISCONSIN PUBLIC SERVICE CORP.
References
TAC-MA1762, NUDOCS 9806190036
Download: ML20249A875 (7)

Text

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June 16; 1998

'Mr. M. L. Marchi -

Site Vice President - Kewaunee Plant .

l.- Wisconsin Public Service Corporation ~

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- P.O. Box 19002 l; Green Ba'y; WI 54307-9002 -

SUBJECT:

KEWAUNEE - REQUEST FOR ADDITIONAL INFORMATION REGARDING -

THE REVIEW OF PROPOSED AMENDMENT REGARDING STEAM l /

~ GENERATOR SLEEVED TUBES - (TAC NO. MA1762)

By a letter dated May 14,1998, Wisconsin Public Seivice Corporation.(WPSC) submitted for staff review a proposed amendment (PA155) to redefine the parent tube pressure boundary for Westinghouse mechanical hybrid expansion joint (HEJ) steam generator (SG) tube sleeves.

The amendment would allow HEJ sleeved tubes having parent tube indications (PTis) to remain ,

in service if PTis exist outside of a specified distance from the bottom of the upper transition f region of the sleeve hardroll joint, in order to continue its review, the staff requests that WPSC-

< respond to the. enclosed questions.

If you have any questions regarding this matter, please contact me at (301) 415-3026.

Sincerely, Original signed by:

l William O. Long, Sr. Project Manager Project Directorate ill-3 Division of React _or Projects lil/lV Office of Nuclear Reactor Regulation

- Docket No. 50-331 -

Enclosure:

As stated

! cc w/ encl: See next page DISTRIBUTION:

Docket File

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DOCUMENT NAME: G:\KEWAUNEE\L_ CRIT.RAI OFFICE , PD33:PM E PD33:LA' E PD33:D E NAME-- WLong # - EBarnhill @f < ,

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,. June 16, 1998

1. ' Mr. M. L. Marchl Site Vice President - Kewaunee Plant Wisconsin Public Service Corporation

= P.O. Box 19002 -

Green Bay, WI 54307-9002

SUBJECT:

KEWAUNEE - REQUEST FOR ADDITIONAL INFORMATION REGARDING THE REVIEW OF PROPOSED AMENDMENT REGARDING STEAM GENERATOR SLEEVED TUBES '(TAC NO. MA1762) -

By a letter dated May 14,1998, Wisconsin Public Service Corporation.(WPSC) submitted for staff review a proposed amendment (PA155) to redefine the parent tube pressure boundary for Westinghouse mechanical hybrid expansion joint (HEJ) steam generator (SG) tube sleeves.

The amendment would allow HEJ sleeved tubes having parent tube indications (PTis) to remain in service if PTis exist outside of a specified distance from the bottom of the upper transition region of the sleeve hardrolijoint. In order to continue its review, the staff requests that WPSC respond to the enclosed questions.

If you have any questions regarding this matter, please contact me at (301) 415-3026.

Sincerely, Original signed by:

William O. Long, Sr. Project Manager Project Directorate ill-3 _j Division of Reactoc Pro'ects Ill/IV Office of Nuclear Reactor 'Reguiation Docket No. 50-331

Enclosure:

As stated

. cc w/ encl: See next page

- DISTRIBUTION:

Docket File PUBLIC -

PD3-3 Reading G. Grant, Ill DOCUMENT NAME: G:\KEWAUNEE\L_ CRIT.RAI OFFICE PD33:PM E PD331A E PD33:D E NAME- WLong F EBamhilliff RBellamy bW\

DATE A/ A//98 6 g/98 / /98 b /l Q98-OFFICIAL RECORD COPY

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, WASHINGTON, D.C. 3008H001 1

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l June 16, 1998 Mr. M. L. Marchi Site Vice President - Kewaunee Plant Wisconsin Public Service Corporation P.O. Box 19002 Green Bay, WI 54307-9002

~

SUBJECT:

KEWAUNEE - REQUEST FOR ADDITIONAL INFORMATION REGARDING THE REVIEW OF PROPOSED AMENDMENT REGARDING STEAM GENERATOR SLEEVED TUBES (TAC NO. MA1762)

By a letter dated May 14,1998, Wisconsin Public Service Corporation (WPSC) submitted for staff review a proposed amendment (PA155) to redefine the parent tube pressure boundary for l Westinghouse mechanical hybrid expansion joint (HEJ) steam generator (SG) tube sleeves.

The amendment would allow HEJ sleeved tubes having parent tube indications (PTis) to remain in service if PTis exist outside of a specified distance from the bottom of the upper transition region of the sleeve hardroll joint. In order to continue its review, the staff requests that WPSC respond to the enclosed questions.

If you have any questions regarding this matter, please contact me at (301) 415-3026.

Sincerely, i

• )

i William O. Long, Sr. Project Manager Project Directorate lil-3 Division of Reactor Projects Ill/IV )

Office of Naclear Reactor Regulation Docket No. 50-331

Enclosure:

As stated cc w/ encl: See next page

, M. L Marchl Wisconsin Public Service Corporation Kewaunee Nuclear Power Plant cc:

Foley & Lardner ATTN: Bradley D. Jackson One South Pinckney Street P.O. Box 1497 Madison, WI 53701-1497 Chairman Town of Carlton Route 1 Kewaunee,WI 54216 .

Harold Reckelberg, Chairman Kewaunee County Board Kewaunee County Courthouse Kewaunee, WI 54216 Attomey General 114 East, State Capitol Madison,WI 53702 U.S. Nuclear Regulatory Commission

~ Resident inspectors Office Route #1, Box 999 Kewaunee, WI 54216-9511 Regional Administrator - Region lil U.S. Nuclear Regulatory Commission 801 Warrenville Road Lisle, IL 60532-4531 James D. Loock, Chief Engineer Public Service Commission of Wisconsin P. O. Box 7854 Madison, WI 53707-7854

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REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED AMENDMENT ON HYBRID EXPANSION JOINT SLEEVED TUBES IN STEAM GENERATORS AT KEWAUNEE NUCLEAR POWER PLANT DOCKET NO. 50-305 By a letter dated May 14,1998, the Wisconsin Public Service Corporation (WPSC) submitted for staff review a proposed amendment to redefine the parent tube pressure boundary for Westinghouse mechanical hybrid expansion joint (HEJ) steam generator (SG) tube sleeves.

The amendment would allow HEJ sleeved tubes having parent tube indications (PTis) to remain in service if PTis exist outside of a specified distance from the bottom of the upper transition region of the sleeve hardrolljoint. In order to continue its review, the staff requests that WPSC respond to the following questions.

Questions related to WCAP-15050. "HEJ Sleeved Tube Lenath-based Degradation Acceptance Criterion." an attachment to the May 14.1998. aoolication:

1. On page 3, there is a discussion of tensile tests on HEJ sleeve specimens as a part of previous license amendments (References 1 and 2). Clarify whether the specimens used in those tensile tests are applicable to the HEJ sleeve configuration in the proposed amendment. Provide statistical results of those tensile tests (e.g., the mean, standard deviation).

2. Table 4 indicates a calculated mean failure pressure of 7051 psi with a standard deviation of 2206 psi. Under steam line break conditions, the mean is 9673 psi with a standard deviation of 2721 psi. Discuss causes, especially structural, that could have contributed

, to such a large uncertainty.

3. Although the mean failure pressure is above the Regulatory Guide (RG) 1.121 allowable value of 4800 psi (i.e., acceptable), the failure pressure at the 95th percentile and 90%/90% tolerance is below the allowable at 4054 psi and 4062 psi, respectively. Also, the calculated probability is 0.091 that the failure pressure would be below the allowable value. Considering that there are about 1500 HEJ sleeved tubes with PTis, the failure pressure of about 136 tubes (1500 x 0.091) would be below the allowable. Discuss the potential impact of failure probabilities calculated in Table 4 on the structural integrity of the HEJ sleeved tubes. .

4. On Page 20, there is a discussion of leak rate experience and information on leakage

- measurement based on Argon 41 and tritium. Describe, in detail, the monitoring system for primary-to-secondary leakage, including administrative controls, if any, on leakage limits in the plant operating procedures. Does the leakage monitoring system satisfy the guidance in the EPRI report, "PWR Primary-to-Secondary Leak Guidelines," TR-1047887 L

a Questions related to Attachment 5. *NDE Techniaue to Determine Lenath Measurements in HEJ Sleeved Tubes With Parent Tube Indications." to the May 14.1998. submittal.

5. Describe, in detail, the quality control that the manufacturer will use to qualify combination probes proposed for the inspection; Specifically (1) Will every probe used in the field be tested for acceptance in the manufacturing facility prior to shipment? If not, discuss the possibility of unqualified and unacceptable probes being used in the inspection, (2)

Discuss acceptance criteria and the testing method to qualify the probes; specifically, will probes be tested at one frequency or mixed frequencies? What length and associated l tolerance will be specified for the distance between the + Point coil and bobbin coil? Will the probes be qualified at the plant site prior to tube inspection? How will probe variability be controlled and monitored? (3) How many probes will be manufactured and how many probes will be used for the Length criterion application?

6. Describe how analysts will be qualified for the HEJ sleeve inspection; Specifically, (1)

Discuss the qualification criteria for the analysts, (2) Will the analyst qualification aM field analysis protocol satisfy EPRI guidelines? (3) How will the analyst variability be monitored and controlled in the field? (4) Describe the test samples used in analyst qualification tests, (5) Discuss WPSC's involvement in the qualification of the analysts.

7. Page 3 provides a discussion of the analyst variability test in detecting the center of the

+ Point coil signal response. It is stated that the variability between analysts in reporting flaw locations corresponds to 0.008 inches to 0.018 inches in axial elevation and that 0.018 inches will be used as the analyst variability in calculating the total NDE uncertainty.

(1) What is the mean and standard deviation of the analyst variability from the test, and (2) is the analyst variability of 0.018 inches comparable to that of the industry in similar inspections?

8. On Page 4, it is stated that a computer algorithm will be used to determine a lower tangent point of the hardroll upper transition (HRUT) region. Discuss the accuracy and applicability of the computer algorithm with respect to the actual sleeve-parent tube conditions.

9. It is not clear to the staff how the parent tube indication (PTI) is defined in the inspection.

In the proposed Bases section, page TS B4.2-4, it is stated that 'the pressure boundary...will allow PTis located in the upper joint to remain in service if there is a minimum non-degraded (i.e., no detectable degradation in the parent tube) hardroll length...." Discuss the procedures that will be used in characterizing and dispositioning indications, e.g., which coil will be used to determine no-detectable degradation (NDD)?

Will the non-quantifiable indication (NQl) be dispositioned as a PTl? Discuss whether the probe would be used to size flaw depth in sleeves because TS 4.2.b.4.b specifies that sleeve indications greater than 24% through wall will be plugged or repaired.

10. In NRC Inspection Report 50-305/96011 (DRS), date February 20,1997, and 50-305/97008 (DRS) dated July 16,1997, the NRC inspector identified, during SG inspection in Kewaunee, that PTis having large voltage responses masked signal d

responses from the sleeve such that potential sleeve flaws may not be detected.

Subsequent to the NRC inspector's findings, WPSC used a high frequency 0.080 inch rotating pancake coil to perform sample inspection of HEJ sleeves. No indication of degradation was identified in the sleeves. In light of the NRC findings, discuss the capability of the proposed eddy current technology (ET); specifically, whether ET can distinguish a sleeve indication and PTl that are located at the same elevation across all ranges of voltage responses.

References:

1. WCAP-14157, " Technical Evaluation of Hybrid Expansion Joint (HEJ) Sleeved Tubes with Indications Within the Upper Joint Zone," August 1994.

2. WCAP-14157, Addendum 1, " Supplemental Leak and Tensile Test Results for Degraded HEJ Sleeved Tubes in Model 44/51 S/G's," September 1994.

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