ML20024G315
| ML20024G315 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 12/17/1971 |
| From: | Wachter L NORTHERN STATES POWER CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20024G313 | List: |
| References | |
| NUDOCS 9102110285 | |
| Download: ML20024G315 (1) | |
Text
-=
NORTHERN STATES POWER COMPANY MIN N E A f*O Lle. MIN N E S OTA 58401 December 17, 1971 Boyce H Grier, Regional Director Region III Compliance Office United States Atomic Energy Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 Dear Mr. Grier MONTICELLO NUCLEAR GENERATING PLANT DOCrJIT NO. 50-263 LICENSE NO. DPR-22 In your telegram of. December 10, 1971, you transmitted information from another nuclear power facility describing the ciretastance in which three main steam relief valves were ejected from their headers during a hot functional test of that system. You requested that we provide you within ten days in writing as to whether-headers as described are installed in the steam lines of our facility. The following description of the head-ers was given.
"The failed header assemblies each consist of two valves mounted vertically in a dead end, 12-inch diameter pipe projecting 90 degree horizontal angle from the main steam line. The two head-ers are mounted at 180 degrees to each other on the opposite sides of the main steam line. The headers were designed to meet Section 1 of the ASME Code by the Bechtel Corporation."
Headers as described above are not installed at the Monticello Nuclear
[
Generating Plant. Each of the four main steam lines have their respec-tivesafetyvalveandsafr',y/reliefvalveattacheddirectlytothe18 o
inch, schedule 80 steam..no as opposed to being located on a dead end header described above. Our piping was designed by the Bechtel Corpora-l tion to meet Class I criteria for nuclear power plants.
Yours very truly, Yeh4>
LJ achter, Vice President Power Production and System Operation LJ/l/br ces R 0 Duncanson C E Larson DEC 2119A 9102110295 720117 DR p
ADOCK 05000263 PDR
.