ML19260C648
| ML19260C648 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 12/20/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Groce R VERMONT YANKEE NUCLEAR POWER CORP. |
| References | |
| NUDOCS 8001080211 | |
| Download: ML19260C648 (1) | |
Text
'~
yf $narog(o, UNITED STATES y, ).-q ',g NUCLEAR REGULATORY COMMISSION x
'c REGION 1
- .f 5A
[
631 PARK AVENUE 0,
U o
KING OF PRUSSIA, PENNSYLVANI A 1940G Docket No. 50-271 DEC 2 01979 Vermont Yankee Nuclear Power Corporation ATTN:
Mr. Robert H. Groce Licensing Engineer 20 Turnpike Road Westborough, Massachusetts 01581 Gentlemen:
The enclosed Circular 79-25, is forwarded to you for information. No written response to this Circular is required.
If you desire additional information regarding thi:, subject, please contact this office.
Sincerely,
/
w Boyce H. Grier Director
Enclosures:
1.
IE Circular No. 79-25 2.
List of Recently Issued IE Circulars CONTACT:
L. E. Tripp (215-337-5282) cc w/encis:
W. F. Conway, Plant Superintendent Ms. J. Abbey, Technical Secretary 1702 166 scolosoD
ENCLOSURE 1 SSINS:
6830 Accession No: 7910250514 UNITED STATES bCDU N, '~'
NUCLEAR REGULATORY COMMISSION LW 6] & J '
0FFICE OF INSPECTION AND ENFORCEMENT WMHINGTON, D.C.
20555 IE Circular No. 79-25 Date: December 20, 1979 Page 1 of 1 SHOCK ARRESTOR STRUT ASSEMBLY INTERFERENCE The Bergen Paterson Pipesupport Corporation reported to the NRC a potential problem with their mechanical shock arrestor
" Strut Assembly." The Bergen Paterson, Part 2540 Strut Assembly, is being used as a rear bracket for different sizes of Pacific Scientific Company (PSCO) mechanical shock arrestors.
Some of the=e shock arrestor sizes may not function as intended due to insufficient cleara..:es.
The following problems were identified:
For PSCO shock arrestors sizes 15 and 50, the Bergen Paterson Part 2540 Strut Assembly does not provide sufficient cle nance for the shock arrestor to function freely, when installed at an off axis angle greater than 83.
For PSCO shock arrestor size 120 there is insufficient clearance throughout the 180 installation angle.
For PSCO shock arrestor sizes 50 and 120 with Bergen Paterson Adaptor Part 2108 the shock arrestor unit may sustain functional damage when the adaptor unit comes in contact with the rear of the snubber, causing distortion of the end dust cover.
PSCO shock arrestors sizes
.35,
.65, 1.5 and 6 do not have this interference condition and therefore are not part of the potential problem of this circular.
Bergen Paterson stopped shipment as of October 1979 of all Part 2540-15, 2540-50, and 2540-120 strut assemblies and is reviewing all applicable design detail drawings, to identify all affected items and the facilities to which those items have been delivered.
Licensees and holders of construction permits are advised to proceed with the inspection of Pacific Scientific Mechanical Shock Arrestor installations with Bergen Paterson Part 2540-15, 2540-50 and 2540-120 Strut Assemblies and deter-mine whether any of the following conditions are applicable:
1.
The shock arrestor installation orientation presents a possible interference problem.
2.
Inspection of shock arrestors 50 and 120 with adaptor show damaged or deformed snubber.
Corrective action should be coordinated with the Strut Assembly supplier (Bergen Paterson) and appropriate resolutions promptly implemented.
1702 167
ENCLOSURE 2 IE Circular No. 79-25 Date:
December 20, 1979 Page 1 of 1 RECENTLY ISSUED IE CIRCULARS Circular Subject First Date Issued To No.
of Issue 79-16 Excessive Radiation 8/16/79 All Radiography Exposures to Members Licensees Of The General Public And A Radiographer 79-17 Contact Problem in 8/14/79 All Power Reactor 58-12 Switches on Licensees with an Opera-General Electric ting License (OL) or Metalclad Circuit Construction Permit (CP)
Breakers 79-18 Proper Installation of 9/10/79 All Power Reactor Target Rock Safety-Licensees with an OL Relief Valves or CP 79-19 Loose Locking Devices 9/13/79 All Power Reactor Licensees on Ingersoll-Rand Pumps with an OL or CP 79-20 Failure of GTE Sylvania 9/24/79 All Power Reactor Licensees Relay, Type PM Bulletin with an OL or CP 7305s Catalog SU12-11-AC with a 120V AC Coil 79-21 Prevention of Unplanned 10/19/79 All Power Reactor Licensees Releases of Radioactivity with an OL or CP 79-22 Stroke Times for Power 11/16/79 All Power Reactor Licensees Operated Relief Valves with an OL or CP 79-2?
Motor Starters and Con-11/26/79 All Power Reactor Licensees tactors Failed to Op-with an OL or CP erate 79-24 Proper Installation and 11/26/79 All Power Reactor Faci-Calibration of Core Spray lities with an OL or CP Break Detection Equipment on BWRs 1702 168