The following is a summary of the information received from Velan Inc. via facsimile:
Affected item: Velan Inc. Disc (part number 8205-012) in 4NPS Class 150 through 900 Swing Check Valve
Callaway Nuclear Plant discovered that a Velan check valve installed in 1999 was stuck open. Velan investigated and determined that in 1979, a design change increased the thickness of the disc to allow the check valve to be used in higher pressure applications than the original design. In 1985, the valve body cavity was enlarged which would preclude the disc from sticking. Therefore, the only affected valves are the valves manufactured between 1979 and 1985.
Velan's records only go back to 1982 for purchase orders of this valve. Their records indicate 157 discs of this part number were shipped to U.S. utilities.
The following actions are being taken with respect to the disc:
- Cancel disc part number 8502-012
- Create a new disc part number to fit the body geometry of 1985 and before
-Create another disc part number to fit the current body geometry.
All affected utilities will be notified within a week, for information and to determine a course of action. As a minimum, Velan will recall all discs of the aforementioned part number in inventory at these utilities.
For any additional information on this matter please contact Victor Apostolescu at 514-748-7748 x 2134 or at victor.apostolescu@velan.com.
This disc has been purchased by nuclear plants in all four USNRC regions.
- * * UPDATE ON 1/24/2018 AT 0906 EST FROM VICTOR APOSTOLESCU TO DAVID AIRD * * *
Revised Part 21 report with corrected part number on page 1. Part number for disc revised to 8205-012.
Notified R1DO (Gray), R2DO (Guthrie), R3DO (Cameron), R4DO (Pick), and Part 21 Group via email.