United States Nuclear Regulatory Commission - Protecting People and the Environment

Bulletin 79-04: Incorrect Weights For Swing Check Valves Manufactured by Velan Engineering Corporation

                               UNITED STATES 
                        NUCLEAR REGULATORY COMMISSION
                    OFFICE OF INSPECTION AND ENFORCEMENT
                           WASHINGTON, D.C.  20555

                               March 30, 1979

                                                       IE Bulletin No. 79-04

INCORRECT WEIGHTS FOR SWING CHECK VALVES MANUFACTURED BY VELAN ENGINEERING 
CORPORATION 

Description of Circumstances: 

North Anna No. 1, Beaver Valley No. 1 and Salem No. 1 have reported to the 
NRC that they had been provided incorrect weights for the six inch swing 
check valves provided by Velan Engineering Corporation.  The six inch valve 
weight provided on the drawing was 225 pounds, whereas the actual weight has
been determined to be 450 pounds.  In addition to the 6 inch valves, 
drawings for 3 inch valves have specified 60 pounds weight while the 
measured wight by the manufacturer was 85 pounds and drawings for 4 inch 
valves have specified 100 pounds weight while the measured weight was 135 
pounds.  The manufacturer presently estimates the following maximum weights 
for swing check valves. 

                                        Maximum Weight (lbs)
Nominal Valve Size                     for High Pressure (1500 psi)

                                        Up to 1973     After 1973

      3 inches                                85             100
      4 inches                               135             150
      6 inches                               450             525
      8 inches                               750            1200
     10 inches                              1200            1200

The NRC staff has indications that in some case, incorrect valve weights 
derived from engineering drawings were used in piping stress analyses.  The 
staff is not aware of a significant difference in the actual weight and the 
weight provided on drawings for the 8 and 10 inch valves. 
.

IE Bulletin No. 79 - 04                                     March 30, 1979 
                                                            Page 2 of 3 

It is recognized that there is a significant number of Velan swing check 
valves used in nuclear systems and it is possible that other stress analyses
have been performed with incorrect valve weights. 

Action To Be Taken By Licensees and Permit Holders: 

1.   List all Seismic Category I piping systems (or portions thereof) where 
     3, 4, or 6, inch diameter Velan swing check valves are installed or are
     scheduled to be installed. 

2.   Verify for all those systems identified in item 1 above that correct 
     check valve weights were used in the piping analysis. Explain how and 
     when the correct valve weights were determined. 

3.   If incorrect valve weights were used, explain what actions have been 
     taken or are planned to re-evaluate the piping systems affected. 

4.   Specify for all the affected systems identified in Item 1 whether 
     modifications were or are required to the piping systems or their 
     supports because of changes in valve weight. Also, include the basis 
     for this determination. For those systems in which the actual valve 
     weight is greater than the design weight provide a summary of stresses 
     and loads and their allowable limits for the piping and its supports. 

5.   Identify the analytical technique including identification of any 
     computer codes used to determine the stresses indicated in Item 4. 

6.   All holders of operating licenses for power reactor facilities are 
     requested to complete Items 1 through 5 as promptly as possible, but no
     later than May 1, 1979. Report in writing by May 1, 1979, to the 
     Director of the appropriate NRC Regional Office to describe your 
     evaluation, any discrepancies in meeting Items 1 through 5, and, if 
     necessary, your plans and schedule for resolution. For planned action, 
     a final report is to be submitted upon completion of your action. 
.

IE Bulletin No. 79 -04                                      March 30, 1979 
                                                            Page 3 of 3 

     A copy of your report(s) should be sent to the United States Nuclear 
     Regulatory Commission, Office of Inspection and Enforcement, Division 
     of Reactor Operations Inspection, Washington, D.C. 20555. These 
     reporting requirements do not preclude nor substitute for the 
     applicable requirements to report as set forth in the regulations and 
     license. 

7.   All holders of construction permits for power reactor facilities are 
     requested to describe your actions to assure that Items 1 through 5 
     will be satisfied before plant startup. Documentation of these actions 
     is to be maintained on site and available for NRC inspection. Report in 
     writing within (60) days of date of Bulletin issuance, to the Director 
     of the appropriate NRC Regional Office, completion of your review and 
     describe any discrepancies in meeting Items 1 through 5 and, if 
     necessary, your plans and schedule for resolution. A copy of your 
     report should be sent to the United States Nuclear Regulatory 
     Commission, Office of Inspection and Enforcement, Division of Reactor 
     Construction Inspection, Washington, D.C.  20555. 

Approved by GAO B180225 (R0072): clearance expires 7/31/80. Approval was 
given under a blanket clearance specifically for identified generic 
problems. 


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