ML19274F097
| ML19274F097 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 05/02/1979 |
| From: | Groce R Maine Yankee |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| WVY-79-42, NUDOCS 7906130119 | |
| Download: ML19274F097 (2) | |
Text
c%
rEnh B.4.2.1 x
TURNPlKE ROAD (RT. 9)
$w7 ENGINEERING OFFICE WESTBORO, MASSACHUSETTS 01581 617-366-9011
%x40 WMY 79-42 May 2, 1979 United States Nuclear Regulatory Commission Region 1 631 Park Avenue King of Prussia, Pennsylvania 19406 Attention: Office of Inspection and Enforcement Mr. Boyce H. Grier, Director Refe rences: (a)
License No. DPR-36 (Docket No. 50-309)
(b)
I&E letter to MYAPC dated March 30, 1979 I&E Bulletin No. 79-04
Dear Sir:
Subject:
Response to I&E Bulletin 79-04 In response to your letter March 30, 1979 I&E Bulletin No. 79-04, Maine Yankee Atomic Power Company submits the following information relative to swing check valves manufactured by the Velan Engineering Corporation.
Item 1 Response:
Maine Yankee has determined that valves manufactured by Velan Engineering Corporation are in use on certain systems at the plant.
More specifically these are:
- a. Three, 4" 1500# swing check valves in use in the High Pressure Safety Injection Piping.
- b. Two, 3" 600# swing check valves in use in the Containment Spray piping.
Item 2. Response:
Velan Engineering Corporation has notified us of the corrected valve weights. We are now checking that the valve weights on the existing Velan drawings are those used in the analysis of these piping systems.
We are confident that this is the case -ince this was the information available at the time the de. sign was estat11shed.
7906130//f
U.S. Nuclear Regulatory Commission May 2, 1979 Attn: Office of Inspection and Enforcement Page 2 The weights used are as follows:
- a. The 4", 1500# valve drawing weight was 100#.
The new valve from Velan is 130#.
- b. The 3", 600# valve drawing weight was 60#.
The new valve from Velan is 75#.
In each case the new Velan weight is greater than that apparently used in the original analysis.
Item 3. Response:
Stone and Webster is currently re-evaluating seismic analyses of Maine Yankee piping systems. The effects of these corrected weights will be evaluated in this process.
Item 4, Response:
The change in valve weight due to the new Velan inputs in the two cases listed in Item 2 above represcuts one to two feet of additional pipe length. Since the pipe stresses typically being found in the reanalyses being performed by Stone & Webster are in the order of one third of S '
H it is difficult to project a fifteen or thirty pound weight change having a serious effect on these pipou or their hangers. We will inform you if any change in status is incurred by this weight change. We will also supply to you the requested summary of stress, loads and allowables for the piping and its supports as soon as we can make it available.
Item 5, Response:
The analytical techniques used in the analysis of these pipes was a dynamic modal analysis using absolute summing techniques. The computer programs used were Stone & Webster's Shock 0 and Shock I.
As you are aware these programs are being re-evaluated as part of the effort in the NRC Order to Show Cause for March 13, 1979 We trust this information is acceptable to you.
However, should you have any questions, please contact us.
Very truly yours, MAINE YANKEE ATCMIC POWER COMPANY Robert H. Groce Licensing Engineer