ML050950334

Ltr., Upcoming SG Tube ISI (Tac No. MC6428)

ML050950334
Person / Time
Site:	Sequoyah
Issue date:	04/21/2005
From:	Pickett D NRC/NRR/DLPM/LPD2
To:	Singer K Tennessee Valley Authority
Pickett D, NRR/DLPM, 415-1364
References
TAC MC6428
Download: ML050950334 (5)

Text

April 21, 2005 Mr. Karl W. Singer Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801

SUBJECT:

SEQUOYAH NUCLEAR PLANT, UNIT 2 - UPCOMING STEAM GENERATOR TUBE INSERVICE INSPECTION (TAC NO. MC6428)

Dear Mr. Singer:

Inservice inspections of steam generator (SG) tubes play a vital role in assuring that adequate structural integrity of the tubes is maintained. As required by the plant Technical Specifications, reporting requirements range from submitting a special report within 15 days following completion of each inservice inspection of SG tubes, that identifies the number of tubes plugged and/or repaired; to submitting a special report within 12 months following completion of the inspection, that provides complete results of the SG tube inservice inspection. The special report containing the complete results shall include the following:

1. Number and extent of tubes inspected.

2. Location and percent of wall-thickness penetration for each indication of an imperfection.

3. Identification of tubes plugged and/or repaired.

A phone conference has been arranged with members of your staff to discuss the ongoing results of the SG tube inspections to be conducted during the upcoming Sequoyah Nuclear Plant, Unit 2 refueling outage. This phone call will occur after the majority of the tubes have been inspected, but before the SG inspection activities have been completed. Enclosed is a list of discussion points to facilitate this phone conference.

The staff plans to document a brief summary of the conference call as well as any material that you may have provided to the staff in support of the call.

Sincerely,

/RA/

Douglas V. Pickett, Senior Project Manager, Section 2 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-328

Enclosure:

List of Discussion Points cc w/encl: See next page

ML050950334 NRR-106 OFFICE PM:LPD2-2 LA:LPD2-2 SC:EMCB SC:LPD2-2 NAME DPickett BClayton LLund MMarshall DATE 04/7/05 04/5/05 04/20/05 04/21/05 Mr. Karl W. Singer SEQUOYAH NUCLEAR PLANT Tennessee Valley Authority cc:

Mr. Ashok S. Bhatnagar, Senior Vice President Mr. Paul L. Pace, Manager Nuclear Operations Licensing and Industry Affairs Tennessee Valley Authority ATTN: James D. Smith 6A Lookout Place Sequoyah Nuclear Plant 1101 Market Street Tennessee Valley Authority Chattanooga, TN 37402-2801 P.O. Box 2000 Soddy Daisy, TN 37384-2000 Mr. Larry S. Bryant, General Manager Nuclear Engineering Mr. David A. Kulisek, Plant Manager Tennessee Valley Authority Sequoyah Nuclear Plant 6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN 37402-2801 Soddy Daisy, TN 37384-2000 Mr. Randy Douet Senior Resident Inspector Site Vice President Sequoyah Nuclear Plant Sequoyah Nuclear Plant U.S. Nuclear Regulatory Commission Tennessee Valley Authority 2600 Igou Ferry Road P.O. Box 2000 Soddy Daisy, TN 37379 Soddy Daisy, TN 37384-2000 Mr. Lawrence E. Nanney, Director General Counsel Division of Radiological Health Tennessee Valley Authority Dept. of Environment & Conservation ET 11A Third Floor, L and C Annex 400 West Summit Hill Drive 401 Church Street Knoxville, TN 37902 Nashville, TN 37243-1532 Mr. John C. Fornicola, Manager County Mayor Nuclear Assurance and Licensing Hamilton County Courthouse Tennessee Valley Authority Chattanooga, TN 37402-2801 6A Lookout Place 1101 Market Street Ms. Ann P. Harris Chattanooga, TN 37402-2801 341 Swing Loop Road Rockwood, Tennessee 37854 Mr. Fredrick C. Mashburn Senior Program Manager Nuclear Licensing Tennessee Valley Authority 4X Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801

DISCUSSION POINTS FOR PLANNED TELEPHONE CONFERENCE OFFICE OF NUCLEAR REACTOR REGULATION TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT, UNIT 2 DOCKET NO. 50-328 The following discussion points have been prepared to facilitate the phone conference arranged with Tennessee Valley Authority to discuss the results of the steam generator (SG) tube inspections to be conducted during the upcoming Sequoyah Unit 2 refueling outage. This phone call is scheduled to occur towards the end of the planned SG tube inspection interval, but before the unit completes the inspections and repairs.

The staff plans to document a brief summary of the conference call as well as any material that is provided in support of the call.

1. Discuss any trends in the amount of primary-to-secondary leakage observed during the recently completed cycle.

2. Discuss whether any secondary side pressure tests were performed during the outage and the associated results.

3. Discuss any exceptions taken to the industry guidelines.

4. For each steam generator, provide a description of the inspections performed including the areas examined and the probes used (e.g., dents/dings, sleeves, expansion-transition, U-bends with a rotating probe), the scope of the inspection (e.g., 100 percent of dents/dings greater than 5 volts and a 20-percent sample between 2 and 5 volts), and the expansion criteria. Also, discuss the extent of the rotating probe inspections performed in the portion of tube below the expansion transition region.

5. For each area examined (e.g., tube supports, dent/dings, sleeves, etc.), provide a summary of the number of indications identified to-date of each degradation mode (e.g., number of circumferential primary water stress corrosion cracking indications at the expansion transition). For the most significant indications in each area, provide an estimate of the severity of the indication (e.g., provide the voltage, depth, and length of the indication). In particular, address whether tube integrity (structural and accident induced leakage integrity) was maintained during the previous operating cycle. In addition, discuss whether any location exhibited a degradation mode that had not previously been observed at this location at this unit (e.g., observed circumferential primary water stress corrosion cracking at the expansion transition for the first time at this unit).

Enclosure

6. Describe repair/plugging plans.

7. Describe in situ pressure test and tube pull plans and results (as applicable and if available).

8. Provide the schedule for steam generator-related activities during the remainder of the current outage.

9. Discuss the following regarding loose parts:

• what inspections are performed to detect loose parts

• a description of any loose parts detected and their location within the SG

• if the loose parts were removed from the SG

• indications of tube damage associated with the loose parts

• the source or nature of the loose parts if known