ML18082A434
| ML18082A434 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 04/29/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Schneider F Public Service Enterprise Group |
| References | |
| NUDOCS 8005220167 | |
| Download: ML18082A434 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION REGION I 631 PARK AVENUE KING OF PRUSSIA, PENNSYLVANIA 19406 April 29, 1980 Docket No. 50-272 50-311 Public Service Electric and Gas Company ATTN:
Mr. F. W. Schneider
. Vice President - Production 80 Park Place Newark, New Jersey 07101 Gentlemen:
The enclosed IE Information Notice No.*80-16, "Shaft Seal Packing Causes Binding in Main Steam Swing Check and Isolation Valves 11 is forwarded to you for information.
No written response is required. If you df:!sire additional information regarding this matter, please contact this office.
Sincerely,
~~
~ Boyce H. Grier
{'.....-- Director
Enclosures:
- 1.
IE Information Notice No. 80-16
- 2.
List of Recently Issued IE Information Notices No. 80-16 CONTACT:
W. Baunack
{215-337-5253) cc w/encls:
F. P. Librizzi,.General Manager - Electric Production E.,N. Schwalje, Manager - Quality Assurance R. L. Mittl, General Manager - Licensing and Environment H. J. Midura, *Manager - Salem Generating Station
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, DC 20555
.SSINS No.:
6870 Accession No.:
8002280667 IE Information Notice No. 80-16 Date:
April 29, 1980 Page 1 of 1 SHAFT SEAL PACKING CAUSES BINDING IN MAIN STEAM SWING DISC CHECK AND ISOLATION VALVES Description of Circumstances:
Recently *two instances of binding of swing check valves have occurred.
During disassembly of the main steam isolation valves at Indian Point 2, it was observed that all four reverse flow check valves were stuck at or near fully open.
These 28 11 valves are manufactured by Atwood & Morrill Co.
Investigation revealed that this condition was apparently caused by excessively tight shaft packing which did not allow free movement of the valve disc.
This condition was reported on January 31, 1980.
An evaluation determined that with the existence of the reported condition in event of a main steam line break upstream of a main steam isolation valve together *with coincident single failure of a main steam isolation valve to close in another loop, the potential existed for blowdown of the contents of two steam generators.
- Main steam line break analyses applicable to Indian Point 2 have been performed assuming blowdown of the contents of one steam generator and have not considered multiple steam generator blowdown.
Therefore, it is possible that the reported condition could have contributed to the exceeding of a safety limit as defined
. in the Unit 2 Technical Specifications if a ~ain steam line break had occurred.
The reported condition was corrected by adjusting the packing of these valves in all four loops and verifying that valve disc movement is not restricted.
During testing in the hot standby mode at the Trojan Nuclear Plant on April 15, 1980, three Of the four main steam line isolation valves failed to close when manually actuated.
The cause of the occurrence was binding in the shaft packing.
The valve is air opened and is closed by gravity, steam.flow and a small spring force; the valves were manufactured by.Atwood & Morrill Co.
The licensee believes that the valves would have closed during actual operations with steam flow in the line.
The valves were repaired and tested satisfactorily.
Modifications to the valves to install air operators to help close the valves are being investigated by the licensee.
This Information Notice is provided as notification of a possible significant matter. It is expected that the recipients will review the informa.tion for possible applicabili~y to their facilities and appropriate corrective action taken.
No written response to this IE Information Notice is required.
- -:i;.':Jo Information Notice No. 80-07 80-08 80-09 80-10 80-11 80-12 80-13 80-14 80-15 ENCLOSURE 2
!E Information Notice No. 80-16 Date:
April 29, 1980 Page l of 1 RECENTLY ISSUED IE INFORMATION NOTICES Subject Date Issued to Issued Pump Fatigue Cracking 2/29/80 All Power Reactor Facil-
\\
The States Company Sliding Link Electrical Terminal Block*
3/7/80
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