United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 83-70, Supplement 1: Vibration-Induced Valve Failures

                                                     SSINS No.: 6835       
                                                     IN 83-70, Supplement 1 

                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
                    OFFICE OF INSPECTION AND ENFORCEMENT
                           WASHINGTON, D.C. 20555
                                     
                                March 4, 1985

Information Notice No. 83-70, SUPPLEMENT 1:    VIBRATION-INDUCED VALVE 
                                                  FAILURES 

Addressees: 

All nuclear reactor facilities holding an operating license (OL) or 
construction permit (CP). 

Purpose: 

This information notice is provided to supplement Information Notice 83-70 
and to alert addressees of additional valve failures and system 
inoperability as a result of loose valve stem antirotation devices. These 
additional failures involve valves supplied by companies other than the 
Anchor Darling Company. It is expected that recipients will review the 
information for applicability to their facilities. Suggestions contained in 
this notice do not constitute NRC requirements; therefore, no specific 
action or written response is required. 

Background: 

Information Notice (IN) 83-70 described events at the Shoreham Station Unit 
1 and the Zimmer Station where valve stem clamps (antirotation devices) had 
become loose because of normal system vibration. The loose stem clamps 
caused the valves to become inoperative. IN 83-70 reported failures of this 
type only on globe valves supplied by the Anchor Darling Company. 

Description of Circumstances: 

A review of licensee event reports (LER) has revealed that failure of the 
antirotation device is not unique to globe valves manufactured by Anchor 
Darling. Valves of other manufacturers also have experienced similar 
failures. These manufacturers were Blaw-Knox, Rockwell-Edward, W-K-M 
Division (WKM), and Copes-Vulcan. The defective valves found in this review 
also were used in systems such as the residual heat removal (RHR) heat 
exchanger discharge, auxiliary feedwater, main steam, containment isolation 
and main feedwater. The events involving failure of the antirotation device 
on valves other than those supplied by Anchor Darling occurred at four 
plants; Quad Cities 1, James A. Fitzpatrick, San Onofre 2, and Surry 1. 

The event at Quad Cities 1 occurred on April 12, 1983, and was reported in 
LER 83-018. While starting the 1C RHR service water pump during a minor 
preventive maintenance on the pumps, the operator observed an excessively 
high discharge pressure and low flow from the pump. An inspection of the RHR
heat exchanger discharge valve revealed that the valve was actually closed 
although 

8502270050 
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                                                     IN 83-70, Supplement 1 
                                                     March 4, 1985         
                                                     Page 2 of 3           

it indicated open in the control room; the motor operator was functioning 
properly, but the valve was not opening. Subsequent licensee investigation 
revealed that the cause of this event was the failure of the antirotation 
pin. The antirotation pin in the valve had fallen out; this pin is held in 
place by a set screw. It was determined that normal system vibration caused 
the set screw to loosen and allowed the antirotation pin to fall out. The 
antirotation pin was replaced, the set screw was tightened securely, and the
valve was tested satisfactorily. The valve was a 12-inch globe valve, 
manufactured by Blaw-Knox Company. 

The event reported in LER 82-047 at James A. Fitzpatrick occurred on October
7, 1982. During normal full-power operation, a reactor scram occurred as the
result of a blockage of the "D" main steam line. Subsequent investigation 
revealed that the "D" inboard main steam isolation valve (MSIV) had its disc
separated from the stem, allowing the main disc to drop to the closed 
position.  The valve disassembly showed that the antirotation pin in the 
MSIV disc was sheared allowing the disc to unscrew. The MSIVs were 
Rockwell-Edward flow balanced stop valves, Type 1612Y. A new stem and disc 
assembly was installed with two antirotation, pins 90 degrees apart. 
Specific attention was paid to ensuring an interference fit of the pins. The 
valve was reassembled and leak tested satisfactorily. Seven previous 
failures of Rockwell-Edward Main steam isolation valves in boiling water 
reactors were reported in Information Notice No. 81-28, dated September 3, 
1981. These failures all resulted in the main disc becoming disconnected 
from the valve stem. 

LER 82-066, dated August 18, 1982, provides a description of an event 
involving failure of an antirotation device, which occurred at San Onofre 2 
on July 19, 1982. While in Mode 3, one auxiliary feedwater (AFW) system 
train was rendered inoperable because of the inability of the AFW control 
valve to open fully. An action of limiting condition for operation was 
initiated. Inspection of the valve revealed that the antirotation 
plate/mechanical indicator was bent and jammed against the yoke guide with 
the valve in the closed position. The damaged antirotation plate was 
replaced. The valve was manufactured by WKM. 

The event at Surry 1 is described in LER 83-043. On September 14, 1983, 
following a reactor trip from 100% power, it was observed that two main 
feedwater regulation valves did not fully close when they received a 
feedwater isolation signal from the reactor protection system. Subsequent 
licensee investigation indicated that one of these valves did not fully 
close because of failure of the stem antirotation device. The second valve 
failed for an unrelated reason. The antirotation device was replaced and the 
valve stroke was reset. This valve was manufactured by Copes-Vulcan, Inc. 
.

                                                     IN 83-70, Supplement 1 
                                                     March 4, 1985         
                                                     Page 3 of 3           

No specific action or written response to this notice is required. If you 
have any questions regarding this matter, please contract the Regional 
Administrator of the appropriate NRC regional office or this office. 


                                   Edward L. Jordan Director 
                                   Division of Emergency Preparedness 
                                     and Engineering Response 
                                   Office of Inspection and Enforcement 

Technical Contact:  H. Bailey, IE
                    (301) 492-9006

Attachment: List of Recently Issued IE Information Notices
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