ML17352A673
| ML17352A673 | |
| Person / Time | |
|---|---|
| Site: | Monticello, Prairie Island  |
| Issue date: | 12/18/2017 |
| From: | O'Connor T Northern States Power Company, Minnesota, Xcel Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-XE-17-015 | |
| Download: ML17352A673 (4) | |
Text
414 Nicollet Mall Minneapolis, MN 55401 800.895.4999 xcelenergy.com December 18, 2017 L-XE-17-015 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant Monticello Nuclear Generating Plant Units 1 and 2 Docket 50-263 Docket 50-282 and 50-306 Renewed Facility Operating License Renewed Facility Operating License Nos.
No. DPR-22 DPR-42 and DPR-60 Anchor Darling Double Disc Gate Valve Information and Status
References:
- 1) Letter from (NRC) to Greg Krueger (NEI), Response from the Nuclear Regulatory Commission Regarding the Anchor Darling Double Disc Gate Valve Industry Resolution Plan, dated July 31, 2017
- 2) Letter from Greg Krueger (NEI) to John Lubinski (NRC), Anchor Darling Double Disc Gate Valve Industry Resolution Plan Update (Project 689),
dated August 4, 2017
- 3) Letter from Joe Pollock (NEI) to Brian Holian (NRC), NSIAC Concurrence on Anchor Darling Double Disc Gate Valve Industry Response Actions (Project 689), dated October 26, 2017
- 4) Boiling Water Reactors Owners Group (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 (Revision 4), dated August 2017 Northern States Power Company, a Minnesota Corporation (NSPM), doing business as Xcel Energy, hereby submits, in accordance with Reference 1, the requested Anchor Darling Double Disc Gate Valve (ADDDGV) information for the Prairie Island Nuclear Generating Plant (PINGP) and the Monticello Nuclear Generating Plant (MNGP).
In Reference 2, the Nuclear Energy Institute (NEI) provided the U.S. Nuclear Regulatory Commission (NRC) a resolution plan for the U.S. nuclear industry to address the known ADDDGV issues. Reference 3 indicated that each utility will provide a listing of their Anchor Darling valve population with active safety functions along with relevant valve information,
Document Control Desk L-XE-17-015 Page 2 of 3 including the results of susceptibility evaluations, repair status, and a repair schedule for each susceptible valve not yet repaired.
The enclosure to this letter contains the following information for each ADDDGV:
Plant Name, Unit, and Valve Identification (I D)
System Valve Functional Description Valve Size Active Safety Function (open, close, both)
Are multiple design basis post-accident strokes required (yes/no)?
Motor Operated Valve (MOV) Expert Panel Risk Ranking (high, medium, low)
Result of susceptibility evaluation (susceptible or not susceptible)
Is the susceptibility evaluation in general conformance with BWROG TP16-1-112_R4 (Reference 4)?
Does the susceptibility evaluation rely on thread friction? If yes, was the coefficient of friction (COF) greater than 0.10? For cases where thread-friction was relied upon, information is provided whether the COF was above or below 0.1.
Was an initial stem-rotation check performed? If yes, include rotation criteria (i.e., :510 degrees or :55 degrees).
Was the diagnostic test data reviewed for failure precursors described in BWROG TP16-1-112_R4 (Reference 4)?
The valve's repair status (i.e., repaired or not repaired)
A repair schedule for each susceptible valve Should you have any questions or require additional information, please contact Mr. Richard Loeffler at (612) 342-8981.
o new commitments and no revisions to existing commitments.
y J. O'Connor or Vice President and Chief Nuclear Officer hern States Power Company - Minnesota
Document Control Desk L-XE-17-015 Page 3 of 3 Enclosure cc:
Administrator, Region III, USNRC Project Manager, Monticello and Prairie Island, USNRC Resident Inspector, Monticello, USNRC Resident Inspector, Prairie Island, USNRC State of Minnesota
L-XE-17-015 Table Page 1 of 1 Xcel Energy Monticello (MT) and Prairie Island (PI) ADDDGV Listing Plant Name Unit Valve ID System Valve Functional Description Valve Size (inches)
Active Safety Function Are multiple design basis post-accident strokes required?
Expert Panel Risk Ranking Result of susceptibility evaluation Is the susceptibility evaluation in general conformance with TP16-1-112R4?(A)
Does the susceptibility evaluation rely on thread friction?
If yes, was the COF greater than 0.10?
Was an initial stem-rotation check performed?
If yes, include rotation criteria Was the diagnostic test data reviewed for failure precursors described in TP16-1-112R4?
Valve repair status (Open,
- Close, Both)
(Yes/No)
(High,
- Medium, Low)
(susceptible or not susceptible)
(Yes/No)
(No),
(Yes, >0.10),
(Yes, 0.10)
(No),
(Yes, 10 deg.),
(Yes, 5 deg.)
(Yes/ No)
(repaired or not repaired)
MT N/A MO-2030 Residual Heat Removal (RHR)
RHR Shutdown Cooling Outboard Isolation Valve 18 Close No Low Not Susceptible Yes Yes, 0.10 Yes, 5 deg Yes Not Repaired (3)
MT N/A MO-2035 High Pressure Coolant Injection (HPCI)
HPCI Steam Line Outboard Isolation Valve 8
Close No Low Not Susceptible Yes No No Yes Repaired (1)
MT N/A MO-2071 High Pressure Coolant Injection (HPCI)
HPCI Test Return Isolation Valve 8
Close No Low Not Susceptible Yes No No Yes Repaired (1)
MT N/A MO-2397 Reactor Water Cleanup (RWCU)
RWCU Inlet Inboard Isolation Valve 4
Close No Low Not Susceptible Yes No No Yes Repaired (1)
MT N/A MO-2398 Reactor Water Cleanup (RWCU)
RWCU Inlet Outboard Isolation Valve 4
Close No Low Not Susceptible Yes No Yes, 5 deg Yes Repaired (2)
PI 1
MV-32115 Component Cooling (CC) 122 Spent Fuel Pool Heat Exchanger Inlet Header Motor Valve 8
Close No Low Not Susceptible Yes No No Yes Not Repaired (3)
PI 2
MV-32117 Component Cooling (CC) 121 Spent Fuel Pool Heat Exchanger Inlet Header Motor Valve 8
Close No Low Not Susceptible Yes No No Yes Not Repaired (3)
(A) Applied Wedge Pin Torque must bound anticipated design basis operating torque requirements and current maximum total torque.
[Table footnotes]
(1) The repair of this MOV occurred in 2013 and included the disassembly of the valve and a re-torque of the upper wedge / stem connection. The pin was not replaced with an Inconel (high strength pin). The original specified pin material was used and the stem was replaced with a two-piece (press-on collar) assembly. Pre-load / torque was applied to ensure the wedge pin was not in the torque load-path. It was confirmed that the applied pre-load was not sufficient to affect the pressed on collar.
(2) The repair of this MOV occurred in 2017 and included a complete valve replacement. The replacement valve was supplied with a one piece (integral) stem. The pin was not replaced with an Inconel (high strength pin). The original specified pin material was used. The valve was supplied by the vendor with sufficient preload on the stem to disc connection to encompass all operational scenarios.
(3) These valves were not repaired as they were deemed Not Susceptible to the failure outlined in the 10 CFR Part 21 notification / BWROG TP16-1-112r4 guidance document.