CNL-17-141, Tennessee Valley Authority - Anchor Darling Double Disc Gate Valve Information and Status
| ML17362A566 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry, Watts Bar, Sequoyah  |
| Issue date: | 12/28/2017 |
| From: | James Shea Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CNL-17-141 | |
| Download: ML17362A566 (10) | |
Text
Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-17-141 December 28, 2017 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Units 1, 2, and 3 Renewed Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 NRC Docket Nos. 50-259, 50-260, and 50-296 Sequoyah Nuclear Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-77 and DPR-79 NRC Docket Nos. 50-327 and 50-328 Watts Bar Nuclear Plant, Units 1 and 2 Facility Operating License Nos. NPF-90 and NPF-96 NRC Docket Nos. 50-390 and 50-391
Subject:
TENNESSEE VALLEY AUTHORITY - ANCHOR DARLING DOUBLE DISC GATE VALVE INFORMATION AND STATUS
References:
- 1. Nuclear Energy Institute (NEI) letter to NRC, Anchor Darling Double Disc Gate Valve Industry Resolution Plan Update (Project 689),
dated August 4, 2017 (ML17220A363)
- 2. NEI letter to NRC, NSIAC Concurrence on Anchor Darling Double Disc Gate Valve Industry Response Actions (Project 689), dated October 26, 2017 (ML17303A031)
- 3. BWROG Topical Report TP16-1-112, Revision 4, Recommendations to Resolve Flowserve 10 CFR Part 21 Notification Affecting Anchor Darling Double Disc Gate Valve Wedge Pin Failures, dated August 2017
U.S. Nuclear Regulatory Commission CNL-17-141 Page 2 December 28, 2017 By letter dated August 4, 2017 (Reference 1), the Nuclear Energy Institute (NEI) provided the NRC a resolution plan for the U.S. nuclear industry to address the known Anchor Darling Double Disk Gate Valve (ADDDGV) issues. By letter dated October 26, 2017 (Reference 2),
NEI informed NRC that each utility would provide a listing of their Anchor Darling valve population with active safety functions along with relevant valve information, including the results of susceptibility evaluations, repair status, and a repair schedule for each susceptible valve not yet repaired. This letter serves to provide this information for Sequoyah Nuclear Plant (SQN), Units 1 and 2.
For Browns Ferry Nuclear Plant, Units 1, 2, and 3, this letter provides the available information. However, TVA has not completed its review of the Browns Ferry Anchor Darling valve population, so the repair schedule cannot be provided at this time. TVA will provide this information after the necessary repairs have been identified.
This letter is also to confirm that Watts Bar Nuclear Plant (WBN), Units 1 and 2, does not use ADDDGVs to support any active safety function.
Enclosures 1 and 2 to this letter contain the following information for each BFN and SQN ADDDGV motor-operated valve, respectively.
- Plant Name, Unit, and Valve ID.
- System.
- Valve Functional Description.
- Valve Size.
- Active Safety Function (open, close, both).
- Are multiple design basis post-accident strokes required (yes/no)?
- Expert Panel Risk Ranking (high, medium, low).
- Result of susceptibility evaluation (susceptible or not susceptible).
- Is the susceptibility evaluation in general conformance with TP16-1-112R4 (Reference 3)?
- Does the susceptibility evaluation rely on thread friction? If yes, was the COF greater than 0.10? For cases where thread-friction was relied upon, information is provided whether the coefficient of friction was above or below 0.1.
- Was an initial stem-rotation check performed? If yes, include rotation criteria (i.e. 10 degrees or 5 degrees).
- Was the diagnostic test data reviewed for failure precursors described in TP16-1-112R4 (Reference 3)?
- The valves repair status (i.e. repaired or not repaired).
- A repair schedule for each susceptible valve.
The new regulatory commitments contained in this letter are included in Enclosure 3.
U.S. Nuclear Regulatory Commission CNL-17-141 Page 3 December 28, 2017 If you have any questions regarding this submittal, please contact Russell Thompson at (423) 751-2567.
- &~~
J. W. Shea Vice President, Nuclear Regulatory Affairs and Support Services
Enclosures:
- 1. Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Anchor Darling Double Disc Gate Valve Information
- 2. Sequoyah Nuclear Plant, Units 1 and 2 - Anchor Darling Double Disc Gate Valve Information
- 3. Summary of Commitments cc (Enclosures):
NRR Director - NRC Headquarters NRC Regional Administrator - Region II NRC Project Manager - Browns Ferry Nuclear Plant NRC Project Manager - Sequoyah Nuclear Plant NRC Project Manager - Watts Bar Nuclear Plant NRC Senior Resident Inspector - Browns Ferry Nuclear Plant NRC Senior Resident Inspector - Sequoyah Nuclear Plant NRC Senior Resident Inspector - Watts Bar Nuclear Plant
Enclosure 1 Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Anchor Darling Double Disc Gate Valve Information Does the Are multiple Is the susceptibility Was an initial stem- Was the diagnostic susceptibility design basis Expert Result of evaluation in rotation check test data reviewed for Active Safety evaluation rely on Valve repair post-accident Panel Risk susceptibility general performed? failure precursors Function thread friction? status Valve Functional Valve Size strokes Ranking evaluation conformance with If yes, include described in Plant Name Unit Valve ID System If yes, was the COF Description (inches) required? TP16-1-112R4? rotation criteria TP16-1-112R4?
greater than 0.10?
(High, (No), (No),
(Open, Close, (Susceptible or (repaired or (Yes/No) Medium, (Yes/No) (Yes, >0.10), (Yes, 10 deg.), (Yes/ No)
Both) not susceptible) not repaired)
Low) (Yes, 0.10) (Yes, 5 deg.)
MAIN STEAM LINE Main (1) (1) Not Browns Ferry 1 1-FCV-001-0055 DRAIN INBOARD 3 Close No Low Not Susceptible Yes No No No (1)
Steam Repaired ISOLATION VALVE MAIN STEAM LINE Main (1) (1) Not Browns Ferry 1 1-FCV-001-0056 DRAIN OUTBOARD 3 Close No Low Not Susceptible Yes No No No (1)
Steam Repaired ISOLATION VALVE REACTOR RECIRC Reactor PUMP 'A' (4) (3) (3) Not Browns Ferry 1 1-FCV-068-0003 Recircula 24 Close No Low Susceptible Yes No Yes, 5 deg. Yes (3) (4)
DISCHARGE Repaired tion VALVE REACTOR RECIRC Reactor PUMP 'B' (4) (3) (3) Not Browns Ferry 1 1-FCV-068-0079 Recircula 24 Close No Low Susceptible Yes No Yes, 5 deg. Yes (3) (4)
DISCHARGE Repaired tion VALVE Reactor RWCU INBOARD (4) (2) (2) (4)
Browns Ferry 1 1-FCV-069-0001 Water CONTAINMENT 6 Close No Medium Susceptible Yes No No Yes Repaired Cleanup ISOLATION VALVE Reactor RWCU OUTBOARD (4) (2) (2) (4)
Browns Ferry 1 1-FCV-069-0002 Water CONTAINMENT 6 Close No Medium Susceptible Yes Yes, >0.10 No Yes Repaired Clean-Up ISOLATION VALVE Reactor RCIC STEAM Core SUPPLY INBOARD (1) (1) Not Browns Ferry 1 1-FCV-071-0002 3 Close No Medium Not Susceptible Yes No No No (1)
Isolation CONTAINMENT Repaired Coolant ISOLATION VALVE RCIC STEAM Reactor SUPPLY Core (1) (1) Not Browns Ferry 1 1-FCV-071-0003 OUTBOARD 3 Close No Medium Not Susceptible Yes No No No (1)
Isolation Repaired CONTAINMENT Coolant ISOLATION VALVE High HPCI INBOARD Pressure (4) (2) (2) (4)
Browns Ferry 1 1-FCV-073-0002 CONTAINMENT 10 Close No Medium Susceptible Yes Yes, >0.10 No Yes Repaired Coolant ISOLATION VALVE Injection High HPCI OUTBOARD Pressure (4) (2) (2) (4)
Browns Ferry 1 1-FCV-073-0003 CONTAINMENT 10 Close No Medium Susceptible Yes Yes, >0.10 No Yes Repaired Coolant ISOLATION VALVE Injection High HPCI OUTBOARD Pressure CONTAINMENT (1) (1) Not Browns Ferry 1 1-FCV-073-0081 1 Close No Low Not Susceptible Yes No No No (1)
Coolant ISOLATION Repaired Injection BYPASS VALVE CORE SPRAY Core SYSTEM I (4) (5) Not Browns Ferry 1 1-FCV-075-0009 3 Both Yes Low Susceptible Yes Yes, >0.10 Yes, 5 deg. Yes (4) (5)
Spray MINIMUM FLOW Repaired VALVE Notes: (1) Stem/wedge connection is a T-head. Not repaired due to not being susceptible.
(2) Wedge pin was replaced with an Inconel pin and wedge pin analysis determined new pin is satisfactory.
(3) Pin shear will not affect valve performance. If the pin sheared the applied torque would tighten the stem to upper wedge and there would be no loose parts since the pin is peened on both ends and broken parts would be captured in the upper wedge (See PDO for PER 692133, Rev 2).
(4) Determine if valve has a pressed-on stem collar. (CR# 1334283).
(5) Original pin remains installed and wedge pin analysis determined pin is satisfactory. Page E1-1 of 3
Enclosure 1 Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Anchor Darling Double Disc Gate Valve Information Does the Are multiple Is the susceptibility Was an initial stem- Was the diagnostic susceptibility design basis Expert Result of evaluation in rotation check test data reviewed for Active Safety evaluation rely on Valve repair post-accident Panel Risk susceptibility general performed? failure precursors Function thread friction? status Valve Functional Valve Size strokes Ranking evaluation conformance with If yes, include described in Plant Name Unit Valve ID System If yes, was the COF Description (inches) required? TP16-1-112R4? rotation criteria TP16-1-112R4?
greater than 0.10?
(High, (No), (No),
(Open, Close, (Susceptible or (repaired or (Yes/No) Medium, (Yes/No) (Yes, >0.10), (Yes, 10 deg.), (Yes/ No)
Both) not susceptible) not repaired)
Low) (Yes, 0.10) (Yes, 5 deg.)
CORE SPRAY Core SYSTEM II (4) (5) Not Browns Ferry 1 1-FCV-075-0037 3 Both Yes Low Susceptible Yes Yes, >0.10 Yes, 5 deg. Yes (4) (5)
Spray MINIMUM FLOW Repaired VALVE MAIN STEAM LINE Main (1) (1) Not Browns Ferry 2 2-FCV-001-0055 DRAIN INBOARD 3 Close No Low Not Susceptible Yes No No No (1)
Steam Repaired ISOLATION VALVE MAIN STEAM LINE Main (1) (1) Not Browns Ferry 2 2-FCV-001-0056 DRAIN OUTBOARD 3 Close No Low Not Susceptible Yes No No No (1)
Steam Repaired ISOLATION VALVE REACTOR RECIRC Reactor PUMP 'A' (4) (3) (3) Not Browns Ferry 2 2-FCV-068-0003 Recircula 24 Close No Low Susceptible Yes No Yes, 5 deg. Yes (3) (4)
DISCHARGE Repaired tion VALVE REACTOR RECIRC Reactor PUMP 'B' (4) (3) (3) Not Browns Ferry 2 2-FCV-068-0079 Recircula 24 Close No Low Susceptible Yes No Yes, 5 deg. Yes (3) (4)
DISCHARGE Repaired tion VALVE Reactor RWCU INBOARD (4) (2) (2) (4)
Browns Ferry 2 2-FCV-069-0001 Water CONTAINMENT 6 Close No Medium Susceptible Yes No No Yes Repaired Cleanup ISOLATION VALVE Reactor RWCU OUTBOARD (4) (2) (2) (4)
Browns Ferry 2 2-FCV-069-0002 Water CONTAINMENT 6 Close No Medium Susceptible Yes Yes, >0.10 No Yes Repaired Cleanup ISOLATION VALVE Reactor RCIC STEAM Core SUPPLY INBOARD (1) (1) Not Browns Ferry 2 2-FCV-071-0002 3 Close No Medium Not Susceptible Yes No No No (1)
Isolation CONTAINMENT Repaired Coolant ISOLATION VALVE RCIC STEAM Reactor SUPPLY Core (1) (1) Not Browns Ferry 2 2-FCV-071-0003 OUTBOARD 3 Close No Medium Not Susceptible Yes No No No (1)
Isolation Repaired CONTAINMENT Coolant ISOLATION VALVE High HPCI INBOARD Pressure (4) (2) (2) (4)
Browns Ferry 2 2-FCV-073-0002 CONTAINMENT 10 Close No Medium Susceptible Yes Yes, >0.10 No Yes Repaired Coolant ISOLATION VALVE Injection High HPCI OUTBOARD Pressure (4) (2) (2) (4)
Browns Ferry 2 2-FCV-073-0003 CONTAINMENT 10 Close No Medium Susceptible Yes Yes, >0.10 No Yes Repaired Coolant ISOLATION VALVE Injection High HPCI OUTBOARD Pressure CONTAINMENT (1) (1) Not Browns Ferry 2 2-FCV-073-0081 1 Close No Low Not Susceptible Yes No No No (1)
Coolant ISOLATION Repaired Injection BYPASS VALVE Notes: (1) Stem/wedge connection is a T-head. Not repaired due to not being susceptible.
(2) Wedge pin was replaced with an Inconel pin and wedge pin analysis determined new pin is satisfactory.
(3) Pin shear will not affect valve performance. If the pin sheared the applied torque would tighten the stem to upper wedge and there would be no loose parts since the pin is peened on both ends and broken parts would be captured in the upper wedge (See PDO for PER 692133, Rev 2).
(4) Determine if valve has a pressed-on stem collar. (CR# 1334283).
(5) Original pin remains installed and wedge pin analysis determined pin is satisfactory. Page E1-2 of 3
Enclosure 1 Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Anchor Darling Double Disc Gate Valve Information Does the Are multiple Is the susceptibility Was an initial stem- Was the diagnostic susceptibility design basis Expert Result of evaluation in rotation check test data reviewed for Active Safety evaluation rely on Valve repair post-accident Panel Risk susceptibility general performed? failure precursors Function thread friction? status Valve Functional Valve Size strokes Ranking evaluation conformance with If yes, include described in Plant Name Unit Valve ID System If yes, was the COF Description (inches) required? TP16-1-112R4? rotation criteria TP16-1-112R4?
greater than 0.10?
(High, (No), (No),
(Open, Close, (Susceptible or (repaired or (Yes/No) Medium, (Yes/No) (Yes, >0.10), (Yes, 10 deg.), (Yes/ No)
Both) not susceptible) not repaired)
Low) (Yes, 0.10) (Yes, 5 deg.)
MAIN STEAM LINE Main (1) (1) Not Browns Ferry 3 3-FCV-001-0055 DRAIN INBOARD 3 Close No Low Not Susceptible Yes No No No (1)
Steam Repaired ISOLATION VALVE MAIN STEAM LINE Main (1) (1) Not Browns Ferry 3 3-FCV-001-0056 DRAIN OUTBOARD 3 Close No Low Not Susceptible Yes No No No (1)
Steam Repaired ISOLATION VALVE REACTOR RECIRC Reactor PUMP 'A' (4) (3) (3) Not Browns Ferry 3 3-FCV-068-0003 Recircula 24 Close No Low Susceptible Yes No Yes, 5 deg. Yes (3) (4)
DISCHARGE Repaired tion VALVE REACTOR RECIRC Reactor PUMP 'B' (4) (3) (3) Not Browns Ferry 3 3-FCV-068-0079 Recircula 24 Close No Low Susceptible Yes No Yes, 5 deg. Yes (3) (4)
DISCHARGE Repaired tion VALVE Reactor RWCU INBOARD (4) (2) (2) (4)
Browns Ferry 3 3-FCV-069-0001 Water CONTAINMENT 6 Close No Medium Susceptible Yes Yes, >0.10 No Yes Repaired Cleanup ISOLATION VALVE Reactor RWCU OUTBOARD (4) (2) (2) (4)
Browns Ferry 3 3-FCV-069-0002 Water CONTAINMENT 6 Close No Medium Susceptible Yes Yes, >0.10 No Yes Repaired Cleanup ISOLATION VALVE Reactor RCIC STEAM Core SUPPLY INBOARD (1) (1) Not Browns Ferry 3 3-FCV-071-0002 3 Close No Medium Not Susceptible Yes No No No (1)
Isolation CONTAINMENT Repaired Coolant ISOLATION VALVE RCIC STEAM Reactor SUPPLY Core (1) (1) Not Browns Ferry 3 3-FCV-071-0003 OUTBOARD 3 Close No Medium Not Susceptible Yes No No No (1)
Isolation Repaired CONTAINMENT Coolant ISOLATION VALVE High HPCI INBOARD Pressure (4) (2) (2) (4)
Browns Ferry 3 3-FCV-073-0002 CONTAINMENT 10 Close No Medium Susceptible Yes Yes, >0.10 No Yes Repaired Coolant ISOLATION VALVE Injection High HPCI OUTBOARD Pressure (4) (2) (2) (4)
Browns Ferry 3 3-FCV-073-0003 CONTAINMENT 10 Close No Medium Susceptible Yes Yes, >0.10 No Yes Repaired Coolant ISOLATION VALVE Injection High HPCI OUTBOARD Pressure CONTAINMENT (1) (1) Not Browns Ferry 3 3-FCV-073-0081 1 Close No Low Not Susceptible Yes No No No (1)
Coolant ISOLATION Repaired Injection BYPASS VALVE Notes: (1) Stem/wedge connection is a T-head. Not repaired due to not being susceptible.
(2) Wedge pin was replaced with an Inconel pin and wedge pin analysis determined new pin is satisfactory.
(3) Pin shear will not affect valve performance. If the pin sheared the applied torque would tighten the stem to upper wedge and there would be no loose parts since the pin is peened on both ends and broken parts would be captured in the upper wedge (See PDO for PER 692133, Rev 2).
(4) Determine if valve has a pressed-on stem collar. (CR# 1334283).
(5) Original pin remains installed and wedge pin analysis determined pin is satisfactory. Page E1-3 of 3
Enclosure 2 Sequoyah Nuclear Plant, Units 1 and 2 - Anchor Darling Double Disc Gate Valve Information Does the Are multiple Is the susceptibility Was an initial Was the diagnostic susceptibility design basis Expert Result of evaluation in stem-rotation test data reviewed Active Safety evaluation rely on Valve repair post-accident Panel Risk susceptibility general check performed? for failure precursors Function thread friction? status Valve Functional Valve Size strokes Ranking evaluation conformance with If yes, include described in Plant Name Unit Valve ID System If yes, was the COF Description (inches) required? TP16-1-112R4?(A) rotation criteria TP16-1-112R4?
greater than 0.10?
(High, (No), (No),
(Open, Close, (susceptible or (repaired or (Yes/No) Medium, (Yes/No) (Yes, >0.10), (Yes, 10 deg.), (Yes/ No)
Both) not susceptible) not repaired)
Low) (Yes, 0.10) (Yes, 5 deg.)
Safety RHR HTX A TO (2) (1)
Sequoyah 1 1-FCV-063-0008-A 8 Open/Close No High Not Susceptible Yes No No Yes Repaired Injection CVCS CHG PUMPS Safety RHR HTX B TO SIS (2) (1)
Sequoyah 1 1-FCV-063-0011-B 8 Open/Close No High Not Susceptible Yes No No Yes Repaired Injection PUMPS Safety SIS PUMPS COLD (2) (3)
Sequoyah 1 1-FCV-063-0022-B 4 Open/Close Yes Low Susceptible Yes No No Yes Not repaired Injection LEG INJ Safety SIS CCP INJ TANK (2) (1)
Sequoyah 1 1-FCV-063-0025-B 4 Open/Close Yes Low Not Susceptible Yes No No Yes Repaired Injection SHUTOFF VLV Safety SIS CCP INJ TANK (2) (1)
Sequoyah 1 1-FCV-063-0026-A 4 Open/Close Yes Low Not Susceptible Yes No No Yes Repaired Injection SHUTOFF VLV SIS CCP INJ TANK Safety (2) (1)
Sequoyah 1 1-FCV-063-0039-A INLET SHUTOFF 4 Open/Close Yes Low Not Susceptible Yes No No Yes Repaired Injection VLV SIS CCP INJ TANK Safety (2) (1)
Sequoyah 1 1-FCV-063-0040-B INLET SHUTOFF 4 Open/Close Yes Low Not Susceptible Yes No No Yes Repaired Injection VLV CONTAINMENT Safety (2) (1)
Sequoyah 1 1-FCV-063-0072-A SUMP FLOW ISOL 18 Open/Close Yes High Not Susceptible Yes No No Yes Repaired Injection VLV CONTAINMENT Safety (2) (1)
Sequoyah 1 1-FCV-063-0073-B SUMP FLOW ISOL 18 Open/Close Yes High Not Susceptible Yes No No Yes Repaired Injection VLV Notes: (A) Applied Wedge Pin Torque must bound anticipated design basis operating torque requirements and current maximum total torque (1) The repair of this MOV included upgrading the pin material to Inconel 718, and torqueing the stem/wedge connection to a value equal to greater than the valve operating torque requirements and the maximum allowable setup valve total torque. A Flowserve analysis has been performed to demonstrate the repaired valve will withstand the maximum Sequoyah valve operating loads. The combination of applied stem/wedge torque and upgraded pin analysis provides additional design margin. Reference Appendix I (2) The maximum allowed stem assembly force calculation uses a thread factor and the collar to wedge friction. This is just used to determine the maximum allowable torque of the stem to upper wedge. The evaluation does not rely on an additional thread frictional force to counteract the operating torque. The connection torque capability is based on the sum of the installed torque of the upper wedge to stem and the strength of the pin.
(3) Repair scheduled for U1C22 refueling outage.
(4) Repair scheduled for U2C22 refueling outage. Page E2-1 of 3
Enclosure 2 Sequoyah Nuclear Plant, Units 1 and 2 - Anchor Darling Double Disc Gate Valve Information Does the Are multiple Is the susceptibility Was an initial Was the diagnostic susceptibility design basis Expert Result of evaluation in stem-rotation test data reviewed Active Safety evaluation rely on Valve repair post-accident Panel Risk susceptibility general check performed? for failure precursors Function thread friction? status Valve Functional Valve Size strokes Ranking evaluation conformance with If yes, include described in Plant Name Unit Valve ID System If yes, was the COF Description (inches) required? TP16-1-112R4?(A) rotation criteria TP16-1-112R4?
greater than 0.10?
(High, (No), (No),
(Open, Close, (susceptible or (repaired or (Yes/No) Medium, (Yes/No) (Yes, >0.10), (Yes, 10 deg.), (Yes/ No)
Both) not susceptible) not repaired)
Low) (Yes, 0.10) (Yes, 5 deg.)
Residual RHR PUMP A-A (2) (1)
Sequoyah 1 1-FCV-074-0003-A Heat INLET FLOW 14 Open/Close No High Not Susceptible Yes No No Yes Repaired Removal CONTROL VLV Residual RHR PUMP B-B (2) (1)
Sequoyah 1 1-FCV-074-0021-B Heat INLET FLOW 14 Open/Close No High Not Susceptible Yes No No Yes Repaired Removal CONTROL VLV Residual RHR HT EXCH A (2) (3)
Sequoyah 1 1-FCV-074-0033-A Heat 8 Open/Close Yes Medium Susceptible Yes No No Yes Not repaired BYPASS Removal Residual RHR HT EXCH B (2) (3)
Sequoyah 1 1-FCV-074-0035-B Heat 8 Open/Close Yes Medium Susceptible Yes No No Yes Not repaired BYPASS Removal Safety RHR HTX A TO (2) (1)
Sequoyah 2 2-FCV-063-0008-A 8 Open/Close No High Not Susceptible Yes No No Yes Repaired Injection CVCS CHG PUMPS Safety RHR HTX B TO SIS (2) (1)
Sequoyah 2 2-FCV-063-0011-B 8 Open/Close No High Not Susceptible Yes No No Yes Repaired Injection PUMPS Safety SIS PUMPS COLD (2) (4)
Sequoyah 2 2-FCV-063-0022-B 4 Open/Close Yes Low Susceptible Yes No No Yes Not repaired Injection LEG INJ Safety SIS CCP INJ TANK (2) (1)
Sequoyah 2 2-FCV-063-0025-B 4 Open/Close Yes Low Not Susceptible Yes No No Yes Repaired Injection SHUTOFF VLV Safety SIS CCP INJ TANK (2) (1)
Sequoyah 2 2-FCV-063-0026-A 4 Open/Close Yes Low Not Susceptible Yes No No Yes Repaired Injection SHUTOFF VLV Notes: (A) Applied Wedge Pin Torque must bound anticipated design basis operating torque requirements and current maximum total torque (1) The repair of this MOV included upgrading the pin material to Inconel 718, and torqueing the stem/wedge connection to a value equal to greater than the valve operating torque requirements and the maximum allowable setup valve total torque. A Flowserve analysis has been performed to demonstrate the repaired valve will withstand the maximum Sequoyah valve operating loads. The combination of applied stem/wedge torque and upgraded pin analysis provides additional design margin. Reference Appendix I (2) The maximum allowed stem assembly force calculation uses a thread factor and the collar to wedge friction. This is just used to determine the maximum allowable torque of the stem to upper wedge. The evaluation does not rely on an additional thread frictional force to counteract the operating torque. The connection torque capability is based on the sum of the installed torque of the upper wedge to stem and the strength of the pin.
(3) Repair scheduled for U1C22 refueling outage.
(4) Repair scheduled for U2C22 refueling outage. Page E2-2 of 3
Enclosure 2 Sequoyah Nuclear Plant, Units 1 and 2 - Anchor Darling Double Disc Gate Valve Information Does the Are multiple Is the susceptibility Was an initial Was the diagnostic susceptibility design basis Expert Result of evaluation in stem-rotation test data reviewed Active Safety evaluation rely on Valve repair post-accident Panel Risk susceptibility general check performed? for failure precursors Function thread friction? status Valve Functional Valve Size strokes Ranking evaluation conformance with If yes, include described in Plant Name Unit Valve ID System If yes, was the COF Description (inches) required? TP16-1-112R4?(A) rotation criteria TP16-1-112R4?
greater than 0.10?
(High, (No), (No),
(Open, Close, (susceptible or (repaired or (Yes/No) Medium, (Yes/No) (Yes, >0.10), (Yes, 10 deg.), (Yes/ No)
Both) not susceptible) not repaired)
Low) (Yes, 0.10) (Yes, 5 deg.)
SIS CCP INJ TANK Safety (2) (1)
Sequoyah 2 2-FCV-063-0039-A INLET SHUTOFF 4 Open/Close Yes Low Not Susceptible Yes No No Yes Repaired Injection VLV SIS CCP INJ TANK Safety (2) (1)
Sequoyah 2 2-FCV-063-0040-B INLET SHUTOFF 4 Open/Close Yes Low Not Susceptible Yes No No Yes Repaired Injection VLV CONTAINMENT Safety (2) (1)
Sequoyah 2 2-FCV-063-0072-A SUMP FLOW ISOL 18 Open/Close Yes High Not Susceptible Yes No No Yes Repaired Injection VLV CONTAINMENT Safety (2) (1)
Sequoyah 2 2-FCV-063-0073-B SUMP FLOW ISOL 18 Open/Close Yes High Not Susceptible Yes No No Yes Repaired Injection VLV Residual RHR PUMP A-A (2) (4)
Sequoyah 2 2-FCV-074-0003-A Heat INLET FLOW 14 Open/Close No High Susceptible Yes No No Yes Not repaired Removal CONTROL VLV Residual RHR PUMP B-B (2) (4)
Sequoyah 2 2-FCV-074-0021-B Heat INLET FROM 14 Open/Close No High Susceptible Yes No No Yes Not repaired Removal CONTROL VLV Residual RHR HT EXCH A (2) (1)
Sequoyah 2 2-FCV-074-0033-A Heat 8 Open/Close Yes Medium Not Susceptible Yes No No Yes Repaired BYPASS Removal Residual RHR HT EXCH B (2) (4)
Sequoyah 2 2-FCV-074-0035-B Heat 8 Open/Close Yes Medium Susceptible Yes No No Yes Not repaired BYPASS Removal Notes: (A) Applied Wedge Pin Torque must bound anticipated design basis operating torque requirements and current maximum total torque (1) The repair of this MOV included upgrading the pin material to Inconel 718, and torqueing the stem/wedge connection to a value equal to greater than the valve operating torque requirements and the maximum allowable setup valve total torque. A Flowserve analysis has been performed to demonstrate the repaired valve will withstand the maximum Sequoyah valve operating loads. The combination of applied stem/wedge torque and upgraded pin analysis provides additional design margin. Reference Appendix I (2) The maximum allowed stem assembly force calculation uses a thread factor and the collar to wedge friction. This is just used to determine the maximum allowable torque of the stem to upper wedge. The evaluation does not rely on an additional thread frictional force to counteract the operating torque. The connection torque capability is based on the sum of the installed torque of the upper wedge to stem and the strength of the pin.
(3) Repair scheduled for U1C22 refueling outage.
(4) Repair scheduled for U2C22 refueling outage. Page E2-3 of 3
Enclosure 3 Summary of Commitments
- 1. TVA will repair the following SQN Unit 1 Anchor Darling double disc gate valve MOVs during the Spring 2018 refueling outage: 1-FCV-063-0022-B, 1-FCV-074-0033-A, and 1-FCV-074-0035-B.
- 2. TVA will repair the following SQN Unit 2 Anchor Darling double disc gate valve MOVs during the Fall 2018 refueling outage: 2-FCV-063-0022-B, 2-FCV-074-0003-A, 2-FCV-074-0021-B, and 2-FCV-074-0035-B.
- 3. By April 30, 2018 TVA will complete its review based on TP16-1-112 R4 of BFN Anchor Darling double disc gate valve MOVs with active safety functions that are susceptible to the condition described in the Flowserve 10CFR21 Update dated July 11, 2017 to determine which valves require repair.
- 4. Upon completion of this review, by May 31, 2018, TVA will provide an updated listing of the BFN Anchor Darling valve information with a repair schedule for each susceptible valve not yet repaired.