ML14174A737
| ML14174A737 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 07/30/2014 |
| From: | Sayoc E C License Renewal Projects Branch 1 |
| To: | Tennessee Valley Authority |
| Sayoc E C, 415-4084 | |
| References | |
| TAC MF0481, TAC MF0482 | |
| Download: ML14174A737 (8) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 July 30, 2014 LICENSEE: Tennessee Valley Authority FACILITY: Sequoyah Nuclear Plant, Units 1 and 2 SUBJECT: SUMMARY OF TELEPHONE CONFERENCE CALL HELD ON JUNE 19, 2014, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND TENNESSEE VALLEY AUTHORITY, CONCERNING REQUESTS FOR ADDITIONAL INFORMATION PERTAINING TO THE SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION (TAC. NOS. MF0481 AND MF0482). The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Tennessee Valley Authority held a telephone conference call on June 19, 2014, to discuss and clarify the staff's requests for additional information (RAIs) concerning the Sequoyah Nuclear Plant, Units 1 and 2, license renewal application. The telephone conference call was useful in clarifying the intent of the staff's RAIs. Enclosure 1 provides a listing of the participants and Enclosure 2 contains a listing of the RAIs discussed with the applicant, including a brief description on the status of the items. The applicant had an opportunity to comment on this summary.
/RA/ Emmanuel Sayoc, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 Enclosures: 1. List of Participants 2. List of Requests for Additional Information cc w/encls: Listserv
July 30, 2014 LICENSEE: Tennessee Valley Authority FACILITY: Sequoyah Nuclear Plant, Units 1 and 2 SUBJECT: SUMMARY OF TELEPHONE CONFERENCE CALL HELD ON JUNE 19, 2014, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND TENNESSEE VALLEY AUTHORITY, CONCERNING REQUESTS FOR ADDITIONAL INFORMATION PERTAINING TO THE SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION (TAC. NOS. MF0481 AND MF0482). The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Tennessee Valley Authority held a telephone conference call on June 19, 2014, to discuss and clarify the staff's requests for additional information (RAIs) concerning the Sequoyah Nuclear Plant, Units 1 and 2, license renewal application. The telephone conference call was useful in clarifying the intent of the staff's RAIs. Enclosure 1 provides a listing of the participants and Enclosure 2 contains a listing of the RAIs discussed with the applicant, including a brief description on the status of the items. The applicant had an opportunity to comment on this summary.
/RA/ Emmanuel Sayoc, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 Enclosures: 1. List of Participants 2. List of Requests for Additional Information cc w/encls: Listserv DISTRIBUTION: See next page ADAMS Accession No.: ML14174A737 *concurred via email OFFICE LA:DLR* PM:RPB1:DLR PM: RPB1:DLR BC:RPB1:DLR PM:RPB1:DLR NAME YEdmonds ESayoc JDaily Y Diaz-Sanabria ESayoc DATE 7/9/14 7/17/14 7/23/14 7/30/14 7/30/14 OFFICIAL RECORD COPY ENCLOSURE 1 TELEPHONE CONFERENCE CALL SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION LIST OF PARTICIPANTS JUNE 19, 2014 PARTICIPANTS AFFILIATIONS Richard Plasse U.S. Nuclear Regulatory Commission (NRC) Emmanuel Sayoc NRC William Holston NRC James Gavula NRC Henry Lee Tennessee Valley Authority (TVA) Dennis Lundy TVA Michael Ryan Henderson TVA Beth Ann Jenkins TVA Jeremy Wayne Mayo TVA Donald G. Sutton TVA REQUESTS FOR ADDITIONAL INFORMATION DISCUSSED SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION JUNE 19, 2014 The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Tennessee Valley Authority (TVA) held a telephone conference call on June 19, 2014, to discuss and clarify the following requests for additional information (RAIs) concerning the license renewal application (LRA). Sequoyah Nuclear Plant, Units 1 and 2 (SQN) draft RAI B.1.38-4, included below, was discussed on June 19, 2014. The requests were clear to TVA. TVA presented a Problem Event Report (PER) number 900557 outlined below, which was discussed by both parties. The PER summarizes the NRC's technical issues around the Ultrasonic Testing (UT) techniques related to the Fire Water and Service Water System aging management programs (AMPs) and TVA's proposal to add commitments to develop, conduct, document, and credit UT technique demonstrations to the AMPs. Proposed commitments are added to the TVA corrective action program (CAP) and will be outlined in TVA's Corporate Nuclear Licensing Letter CNL-14-105 scheduled to be submitted to the NRC on or around July 3, 2014. As such the staff elected to not send the following draft RAIs to the applicant in lieu of the scheduled letter. RAI B.1.38-4 Use of UT to detect debris in Service Water Integrity program Background: In the clarification dated December 16, 2013, to the response for RAI 3.0.3-1 (which related to the staff's questions for the use of UT to detect flow blockage in the Fire Water System program), TVA stated that it had "demonstrated the use of UT on the ERCW [essential raw cooling water] system to identify blockage from silt and clams." In a follow-up RAI B.1.13-4 questioning the effectiveness of the UT technique to detect flow blockage, the staff specifically asked TVA to describe the practical demonstration performed on the ERCW system and to describe the results of the field inspections conducted using this UT procedure. By letter dated April 22, 2014, TVA responded to the additional questions in RAI B.1.13-4 and placed a copy of the associated procedure, N-UT-11, "Ultrasonic Examination for Detecting and Measuring Fluid Levels in Austenitic and Ferritic Systems," on the Certrec website for NRC review. Regarding the practical demonstration, TVA stated: "No demonstrations were formally conducted or documented for this process." Regarding the results of field inspections using this UT procedure, the response stated that TVA at Watts Bar performs clam/silt inspections quarterly using the described technique, and TVA at SQN performs clam/silt inspection on an annual frequency. The response also added: "TVA did not perform any demonstration UT field test inspection for flow blockage."
Supplemental information subsequently provided by SQN on June 13, 2014, states that the referenced preventive maintenance (PM) program clam/silt inspections are not credited inspections in the SQN Generic Letter (GL) 89-13 program, and are not credited in the Service Water Integrity AMP. TVA also stated that the UT inspections of selected ERCW stagnant/dead leg piping to detect clams/silt are "informal supplemental inspections that are used as an early diagnostic indicator of potential piping blockage in the ERCW stagnant/dead leg piping-"
- 2 - On March 3, 2014, TVA also placed inspection documentation for nine UT-detected piping blockages on its Certrec website for the NRC to review. The nine documents spanned the period between 2005 and 2013. The following statement is included in that documentation: During performance of PM06306166, ultrasonic [testing] showed silt in the dead legs of the ERCW piping from the main header 1A to normally closed valve 1-67-687, Flood Mode Supply to CCS [component cooling system] and from the main supply header 1B to normally closed valve 1-67-544, Emergency Supply to CCS Surge Tank A. UT showed that the water is not being blocked by the silt and if needed the system can still perform its intended function. A WO [work order] is being requested to flush these dead legs and prevent this silt from entering the flood mode system. Issue:
TVA currently performs aging management activities through its PM program that are not described in the Service Water Integrity AMP. The specific activities are monitoring the stagnant/dead leg portions of the ERCW system for fouling using a UT technique. The results of these activities are used as the basis for taking corrective actions (i.e., system flushing) and for concluding that existing debris in the system would not prevent the system from performing its function. Since these activities result in the same actions as would be taken for a credited activity, and conclusions about system functions are drawn based on information obtained from these activities, they cannot be treated as informal supplemental inspections.
Since TVA has stated that the UT clam/silt inspections are not credited in either the GL 89-13 program or the Service Water Integrity program, it is not clear to the staff what aging management activities for this aging effect are being credited as part of the Service Water Integrity AMP, and how operating experience information, resulting from the UT inspections, is being factored back into the extent and frequency of the activities being credited by the Service Water Integrity AMP. Request: 1) For the period of extended operation, describe the specific aging management activities that will be performed to ensure, as specified in SQN's response to GL 89-13, stagnant/dead leg piping is not fouled or clogged. Include the relevant portions of existing implementing procedures and provide the frequency of the activities. 2) For the period of extended operation, describe how the operating experience information obtained through the UT inspections are accounted for in activities credited by the Service Water Integrity program.
- 3) For the period of extended operation, a) describe how system function will be verified if UT inspections detect debris, and b) provide the programmatic constraints to ensure that UT inspections will not be credited as part of the Service Water Integrity Program, unless the technique has been demonstrated to effectively identify the amount and type of debris.
- 3 - PER 900557 GL 89-13 Service Water - Managing Fouling in Dead Legs In the TVA SQN 89-13 letter to the NRC dated September 22, 1995 (S64950922800), SQN provided a revised GL 89-13 Service Water System program and status update.
The TVA response to GL 89-13 Recommended Program C (fouling or clogging of infrequently used cooling loops) provided an engineering evaluation for not flushing dead leg piping and stated that the material condition of dead leg piping would be monitored by nondestructive examination (UT wall thickness checks) under the SQN raw water fouling and corrosion control program. TVA currently uses UT (under the PM program) to check for fouling inside of dead leg piping off of the 24 ERCW headers to spool pieces providing flood mode cooling to hot sample coolers and the Spent Fuel Pit Cooling system heat exchangers and makeup water to CCS surge tanks A/B. Silt/clams have been detected in the past PM performances and corrective actions taken to address the findings. These UT flow blockage PMs are not credited in the GL 89-13 Service Water System program for managing fouling of these dead legs. In a draft LR RAI to the SQN LR Project, on 6/18/14, the NRC has questioned the method by which fouling/debris in dead leg piping is managed under the GL 89-13 Service Water Program. The NRC has also questioned the adequacy of the demonstration documentation of the UT pipe blockage detection method used to detect silt/clams/debris inside dead leg/stagnant piping. Corporate/SQN 89-13 Program Owners (and Licensing) have been notified. Issues that this PER need to address: (1) Re-evaluate the 89-13 September 22, 1995, SQN letter to the NRC (S64950922800), SQN GL 89-13 response in regard to managing fouling/silt/clams/debris in ERCW dead leg piping. Based on this re-evaluation, supplement the existing GL 89-13 program to include additional methods such as flow tests/flushes, radiograph (RT) or a demonstrated UT method to supplement the current GL 89-13 credited methods. Document the frequency of the 89-13 flow blockage inspection activities in this PER. (2) Describe how the operating experience information obtained through the UT inspections (for fouling/silt/clams/debris in ERCW and filled Firewater System dead leg piping) are accounted for in activities credited by the Service Water Integrity LR AMP for SQN.
(3) Provide effectiveness demonstration documentation (analysis, white paper, critical thinking, etc.,) for the UT method for detecting pipe fouling/blockage/silt/debris currently used under the PM program.
- 4 - (4) If the UT method for detecting pipe fouling/blockage/silt/debris has been demonstrated reliable/credible/acceptable in #3, evaluate crediting this methodology for the Service Water (ERCW) Integrity LR AMP for SQN. (5) This PER shall be completed prior to June 1, 2016.
SUBJECT: SUMMARY OF TELEPHONE CONFERENCE CALL HELD ON JUNE 19, 2014, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND TENNESSEE VALLEY AUTHORITY, CONCERNING REQUESTS FOR ADDITIONAL INFORMATION PERTAINING TO THE SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION (TAC. NOS. MF0481 AND MF0482). DISTRIBUTION: HARD COPY: DLR RF E-MAIL: PUBLIC RidsNrrDlr Resource RidsNrrDlrRpb1 Resource RidsNrrDlrRpb2 Resource RidsNrrDlrRerb Resource RidsNrrDlrRarb Resource RidsNrrDlrRasb Resource RidsNrrPMSequoyah Resource beth.mizuno@nrc.gov brian.harris@nrc.gov john.pelchat@nrc.gov gena.woodruff@nrc.gov siva.lingam@nrc.gov wesley.deschaine@nrc.gov galen.smith@nrc.gov scott.shaeffer@nrc.gov jeffrey.hamman@nrc.gov craig.kontz@nrc.gov caudle.julian@nrc.gov generette.lloyd@epa.gov gmadkins@tva.gov clwilson@tva.gov hlee0@tva.gov dllundy@tva.gov