IR 05000213/1993009

Insp Rept 50-213/93-09 on 930524-28.No Violations Noted. Major Areas Inspected:Licensee ISI Program & Related Activities,Sg Tube Eddy Current Insp Program Including Data Acquisition & Analysis

ML20045E312
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	06/17/1993
From:	Gray E, Mcbrearty R, Ray A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20045E309	List: IR 05000213/1993009
References
50-213-93-09, 50-213-93-9, NUDOCS 9307020005
Download: ML20045E312 (9)

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I U. S. NUCLEAR REGULATORY COMMISSION

REGION I

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Report No.:

50-213/93-09

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Docket No.:

50-213 License No.:

DPR-61

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- 1 Licensee:

Connecticut Yankee Atomic Power Company P.O. Box 270 Hartford, Connecticut 06141-0270 Facility Name:

Haddam Neck

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i Inspection At:

Haddam Neck, Connecticut j-Inspection Conducted:

May 24 - 28,1993

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4/4[93 Inspectors:

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R. A. McBrearty, Reac'- Mgineer, Dale '

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Materials Section, L

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A. N. Ray, Reactor Engineer, MS, EB, DRS Date Approved By:

1. l) /(cd b b d. Efw a 6 - n -91 E. H. Gray,' Chief, Materials Section Date Engineering Branch, DRS F

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9307020005 930624 PDR ADOCK 05000213-O PDR

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Areas Insoected: An announced inspection was conducted of the licensee's inservice inspection (ISI) program and related activities, the steam generator tube eddy current inspection program including data acquisition and analysis, and the licensee's alternate steam generator tube plugging criteria regarding defects within the tubesheet in the roll expansion region of the tube.

Results: The programs are being implemented in compliance with applicable ASME Code, Technical Specification and regulatory requirements. Nondestructive examinations including steam generator tube eddy current inspections are conducted by qualified and certified individuals who, in addition to their SNT-TC-1 A qualification, are required to successfully pass the licensce's training program prior to performing work at the plant.

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L DETAILS 1.0 INSERVICE INSPECTION (ISI) PROGRAM (INSPECTION PROCEDURE l

73051)

An inservice inspection program is mandated by the ASME Boiler and Pressure Vessel Code,Section XI, and is essential to protect health and safety in that it assures structural integrity l_

and leak tightness of the reactor coolant system pressure boundary.

The current refueling outage (Spring,1993) is the first scheduled refueling outage of the second period of the third inspection interval. The interval commenced on January 1,1988 and is scheduled to end on January 1,1998. The applicable Code for the interval is the 1983 Edition, Summer 1983 Addenda of Section XI with the following exceptions: (a), the extent of examination for Code Class 1 and Code Class 2 piping welds has been octemined by the 1974 Edition thru Summer 1975 Addenda as permitted by 10 CFR 50.55a(b); and (b), the alternate rules of ASME Code Case N-408 are being used for the examination of all pressure

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retaining welds in austenitic stainless steel or high alloy piping in Class 2 systen.s.

The Third 10-year Internal Inservice Inspection Program summary, revision 0, was submitted by letter dated June 30,1987, to the NRC for review and approval. By letter dated May 24, 1988, in response to the NRC March 18,1988 request for additional information, the licensee submitted the information and revision 1 of the program plan summary.

i Relief request 3.16 regarding a hydrostatic pressure test on the chemical volume and contro'

system was denied by the staff for reasons documented in the NRC safety evaluation report.

Additionally, the staff concluded that the Haddam Neck plant third 10-year ISI program plan with specific written reliefs and the hydrostatic pressure test meet the requirements of 10 CFR 50.55.a(g), and is acceptable.

The licensee's ISI program includes provisions for training (in the use of site specific l

procedures) and testing vendor nondestructive examination (NDE) personnel prior to their l

performing NDE at the site. The written test questions and test results of selected vendor

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personnel were examined to determine whether the program was complied with and to determine the adequacy of the questions with respect to the individual's certified level of

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qualification. Additionally, results of the practical test (performance demonstration)

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The inspector determined that the written and practical tests were an excellent method for determining the competency of vendor examination personnel and provides the licensee with an extra measure of control over its ISI program and vendor activities. Program control is further enhanced with the use of an upgraded computer program for tracking program status and trending ISI examination results. The computer program, now in place at the Haddam Neck facility, is discussed in NRC Inspection Report 93-02, issued on February 11,199?

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regarding Millstone Units 1 and 3.

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Couclusions The licensee's ISI program complies with ASME Code Section XI and regulatory requirements. The Connecticut Yankee Atomic Power Company has taken positive actions to enhance its control over the ISI program at Haddam Neck as evidenced by the program for training and testing vendor nondestructive examination personnel, and with the installation of

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an upgraded computer program for tracking ISI program status and trending ISI examination

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results.

J 2.0 INSERVICE INSPECTION ACTIVITIES (IP 73753)

t During this inspection the licensee's contractors were performing ultrasonic examinations and eddy current examinations of steam generator tubes in each of the four steam generators.

Examiners employed by ABB/AMDATA were responsible for the ultrasonic examinations

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and Babcock & Wilcox personnel were responsible for performing the eddy current examinations (data acquisitions and data analysis).

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The ultrasonic examination of welds 20206-50-001 and -003 on the high pressure coolant injection system, and the calibration of the ultrasonic examination system for the reactor coolant pump flywheel examinations were selected for inspection. The inspection was performed to determine whether the examination complied with Code and regulatory

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requirements, the results were properly recorded, and the examiners were qualified to perform their assigned responsibilities.

The inspectors determined that the weld examinations were performed in accordance with applicable ASME Section XI requirements by properly qualified examiners. The examination results were clearly documented and the locations of reflectors were plotted to aid in the evaluation process.

The reactor coolant pump flywheel examination is an augmented examination discussed in j

Regulatory Guide (RG) 1.14, " Reactor Coolant Pump Flywheel Integrity," and is not required by ASME Section XI. The RG requires an in-place ultrasonic volumetric examination of the areas of higher stress concentration at the bore and keyway ht

.I approximately 3-year intervals, during the refueling or maintenance shutdown coinciding with the inservice inspection schedule as required by Section XI of the ASME Code.

The flywheels at Haddam Neck are scanned from four gage holes, one in each quadrant of

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the flywheel, into which the appropriate ultrasonic probe is placed. The examination system must be calibrated with each of the three probes in accordance with the requirements of the licensee's procedure No. NU-UT-24, Revision 7, " Ultrasonic Examination Reactor Coolant J

Pump Flywheel." The procedure provides detailed step by step calibration instructions which refer to a drawing of the flywheel calibration block No. CYW-47 that is attached to the procedure. The probes consist of two 0 azimuth probes measuring 0.920" diameter and 0.721' diameter respectively, and a 3% angle beam probe. Each probe is intended to examine the flywheel bore and keyway region to the greatest extent possible.

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The calibration using the two O probes was completed as specified by the procedure, and the resulting distance-amplitude-correction curves were locked into the memory bank of tha EPOCH II ultrasonic instrument to be recalled when needed to perform the flywheel examinations. The calibration of the 3% angle beam probe could not be completed because of a noise level and the inability to detect one of the required calibration holes..When the probe was connected to the instrument the Level II examiner noted a significant increase in noise level and subsequently the inability to detect a required calibration hole. By the process of elimination the problem was determined to be with the probe and, therefore, the calibration process was terminated until the angle beam probe could be repaired or replaced.

Because of anticipated radiation levels at the flywheel examination area and considering the licensee's ALARA program, the decision was made to postpone the flywheel examination until all three of the required probes were available. The systematic way the examiner identified the faulty piece of equipment, after recognizing the problem, was evidence of his knowledge of the method and familiarity with the equipment which allowed him to quickly determine that the calibration process was not proceeding properly.

Conclusions Ultrasonic examinations at Haddam Neck were performed in compliance with Code and regulatory requirements by appropriately qualified examiners. Evidence of examiner competence was manifested during the ultrasonic calibration process in preparation for -

reactor coolant pump flywheel examinations.

I 3.0 STEAM GENERATOR TUBE EDDY CURRENT EXAMINATION (IP 73753)

The Connecticut Yankee facility is a Westinghouse four-loop, pressurized water reactor with series 27 steam generators. Each generator contains 3794 U-bend Inconel 600 tubes with 0.750" outside diameter, 0.640" inside diameter, and a 0.055" nominal wall thickness. In 1975 the plant changed from phosphate (PO) chemistry control to all volatile treatment

(AVT) chemistry control which is maintained at the present time.

All of the tubes in each of the four steam generators were scheduled for eddy current j

inspection during the current 1993 refueling outage. Each tube is intended to be inspected J

full length using a bobbin coil probe. Approximately 77% on the scheduled bobbin coil probe inspections, including data analysis, was completed at the conclusion of this inspection on May 28,1993.

The steam generator tube status prior to the outage was as follows:

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~i Steam Generator Number Number of Tubes Plugged

% of Tubes Plugged

236 6%

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402 10.5 %

103 2.7%

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448 11.8 %

TOTAL 1189 7.8 %

The inspector observed the eddy current inspection of the following tubes in steam generator

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Row Column

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40 I

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The inspector determined that data were recorded as the eddy current (Bobbin coil,0.540

probe) was withdrawn from the tube as specified by the procedure. This portion of the tube

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inspection was performed from the fourth support on the cold leg side, over the U-bend to -

the hot leg tube sheet. In addition to the above, the inspectors visited the offsite data

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analysis station and interviewed personnel responsible for analyzing data and reporting results. That was done to ascertain that the data analysis guidelines established by the licensee were being complied with.

In 1987, the licensee developed data analysis guidelines to minimize the probability of missing tube defects. At that time the guidelines were implemented on an informal basis.

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Since then the guidelines have been expanded on and include a program for training and testing contractor eddy current data analysts. The testing is conducted with the use of data containing typical defects previously found in the Connecticut Yankee steam generator tubes.

Additionally, the program requires the use of Primary and Secondary Analysts and a Lead Analyst who is responsible for resolving differences when the primary and secondary analyst'

I disagree on a call. If the Lead Analyst overrules any defect call, the reason for overruling must be documented and a second Lead Analyst is required to review the pertinent data tape and acknowledge his concurrence.

The inspectors determined that the process was operating as planned, including a system for l

tracking data through the process until completion of the analysis.

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At the conclusion of this inspection on May 28,1993, the inspection of tubes in all four ~

steam generators was in progress. The eddy current inspection status was as follows: -

Stenm Generntor #

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1. Bobbin Coil Examination

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4 Intal Tubes Scheduled for Inspection 3558 3392 3691 3346 13,987 Inspection Completed Full Length 3465 2723 2628 2545 11,361

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Analysis Completed Full Length 3249 2514 2540 2405 10,708 l

2. Tube Suonort Plate

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• (MRPC - Ilot-Lee)

101 152

0 253 Tubes Scheduled for Inspection

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3. Ton of Tube Sheet (MRPC-Hot Lee)

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Tubes Scheduled for Inspection 500

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500 l

4. U-Bend (MRPC)

Tubes Scheduled for Inspection

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80 177 i

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• MRPC - Motorized Rotating Pancake Coil The MRPC probe inspections were scheduled to begin when the bobbin coil inspections were completed. The completed inspections identified a number of tubes in each steam generator which may require repair and those tubes were scheduled for inspection using the MRPC probe before a final decision regarding the need for repair would be made. None of the MRPC inspections were performed at the time the inspectors left the site, on May 28,1993.

In addition to the eddy current inspection of steam generator tubes, the licensee plans to perform roll expansion of selected tubes. That work had not commenced at the time of this

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inspection, but the cor. trolling procedures were in place.

On May 10,1993, the NRC staff met with the licensee to discuss the status of its alternate steam generator tube plugging criteria regarding defects within the tubesheet in the roll expansion region of the tube. The licensee stated that it has been working on a long term steam generator tube flaw management plan which includes re-rolling of the tubes. The plant Technical Specification requires 1" of sound roll above the uppermost crack tip. The re-rolling of selected tubes is expected to provide the required length of sound roll.

The Babcock & Wilcox (B&W) Nuclear Service Company has been contracted by the

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licensee to perform the re-rolling process. B&W Field Procedure for W-27 Re-Roll, Revision 4 will govern the work and provides direction for the re-roll of tubes in the

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tubesheet above the current transition region.

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The procedure identifies the equipment required for the process and the sequential steps and -

precautions necessary to obtain satisfactory results. Controls have been established including torque calibration of the rolling equipment before and after roll expansion, and recording on video tape all process activities. Additionally, after performing the maximum allowed

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number of roll expansions using a particular roll expander, a post torque check must be

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performed and the roll expander must be replaced.Section VI of the field procedure

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identifies the methor' for verifying that the desired results have been achieved and the method for dispositioning tubes that do not meet the design criteria of Specification 51-1219695,

"C. Y. Re-Roll Process Specification", which is a B&W proprietary specification.

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Conclusions The licensee continues to examine all of the tubes in each of the four steam generators which is in excess of its Technical Specification requirements. Additionally, the training and testing program, which is invoked on all personnel responsible for analyzing eddy current data, assures that the analysts are familiar with the type of steam generator tube flaws that have been detected at the plant during previous inspections. Those actions are evidence of the i

licensee's desire to determine the condition of the steam generators at Haddam Neck and to maintain the plant in a safe condition.

4.0 EXIT MEETING i

The inspectors met with licensee representatives, denoted in Attachment 1, at the conclusion-of the inspection on May 28,1993. The inspectors summarized the scope and findings of the inspection.

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I Attachment 1 Connecticut Yankee Atomic Power Company

• E. Annino, Sr. Analyst

• M. Bain, Engineering Manager

• J. dei 2wrence, Inservice Inspection Supervisor

• D. Ray, Director, CY Unit-i

• J. Stetz, Vice President Haddam Neck US Nuclear Regulatory Commission j

l W. Raymond, Senior Resident Inspector j

R. McBrearty, Reactor Engmeer j

A. Ray, Reactor Engineer i'I l

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