ML19323D669
| ML19323D669 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 04/29/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8005220118 | |
| Download: ML19323D669 (1) | |
Text
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION o
e REGION I C
631 PARK AVENUE KING OF PRUSSIA, PENNSYLVANIA 19406 April 29, 1930 Docket Nos. 50-317 50-318 Baltimore Gas and Electric Company ATTN:
Mr. A. E. Lundvall, Jr.
Vice President, Supply P. O. Box 1475 Baltimore, Maryland 21203 Gentler.en:
The enclosed IE Informe. tion Notice No. 80-16, " Shaft Seal Packing Causes Binding in Main Steam Swing Check and Isolation Valves" is forwarded to you for infomation.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
[ 56
/C Scyce H. Grier Director
Enclosures:
1.
IE Information Notice No. 30-16 2.
List of Recently Issued IE Infomation Notices No. 80-16 CONTACT:
W. Baucack (215-337-5253) cc w/encls:
R. M. Douglass, Manager, Quality Assurance L. B. Russell, Chief Engineer T. Sydnor, General Supervisor, Operations QA R. C. L. Olson, Senior Engineer K. H. Sebra, Principal Engineer 80 05 2 mo II1T
(
SSINS No.:
6870 Accession No.:
UNITED STATES 8002280667 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, DC 20555 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 c
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" 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 togethe with coincident single failure of a main steam isolation valve to close.9 anodi.y loop, the potential existed for blowdown of the contents of two steam generators.
Main steam line break analyses applicable to Indian Po'nt 2 have been performed assuming blowdown of the contents cf one steam generator and have not considered multiple steam generator blowdewn.
fnerefore, 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 main steas line break had occurred.
The reported condition wa's corrected by adjusting the packing of these valves in all four loops and verifying that valve disc movemanr. is not restricted.
During testing in the hot standby mode at the Trojan lluclear Plant on Anril 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 grtvity, 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 information for possible applicability to their facilities and appropriate corrective action taken.
No written response to this IE Information Notice is required.
~
l ENCLOSURE 2 IE Information Notice No. 80-16 Date:
April 29, 1980 Page 1 of 1 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued to Notice No.
Issued 80-07 Pump Fatigue Cracking 2/29/80 All Power Reactor Facil-ities with an Operating License (OL) or Construc-tion Permit (CP) and applicants for a CP 80-08 The States Company Sliding 3/7/80 All Power Reactor Facil-Link Electrical Terminal ities with an OL or CP Block
)
80-09 Possible Occupational Health 3/7/80 All Power Reactor Facil-Hazard Associated with Closed ities with an OL or CP Cooling Systems for Operating Power Plants 80-10 Partial Loss of Non-Nuclear 3/7/80 All Power Reactor Facil-Instrument System Power Sup-ities with an OL or CP ply During Operation 80-11 Generic Problems With ASCO 3/14/80 All Power Reactor Facil-Valves in Nuclear Applica-ities with an OL or CP, tions including Fire Pro-Fuel Fabrication and tection Systems Processing Facilities 80-12 Instrument Failure causes 3/31/80 All Power Reactor Facil-Opening of PORV and Block ities with an OL or CP Valve 80-13 General Electric Type SBM 4/2/80 All Power Reactor Facil-Control Switches - Defective ities with an OL or CP CAM Followers 80-14 Safety Suggestions from 4/2/80 All Power Reactor Facil-Employees ities with an OL or CP, Fuel Fabrication and Processing Facilities and Materials Priority 1 Licensees 80-15 Axial (Longitudinal) 4/21/80 All Power Reactor Facil-Oriented Cracking in ities with an OL or CP Piping
.