United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 91-42: Plant Outage Events Involving Poor Coordination Between Operations and Maintenance Personnel During Valve Testing and Manipulations

                                 UNITED STATES 
                          NUCLEAR REGULATORY COMMISSION
                      OFFICE OF NUCLEAR REACTOR REGULATION
                             WASHINGTON, D.C.  20555

                                  June 27, 1991

Information Notice No. 91-42:  PLANT OUTAGE EVENTS INVOLVING 
                                   POOR COORDINATION BETWEEN OPERATIONS AND 
                                   MAINTENANCE PERSONNEL DURING VALVE 
                                   TESTING AND MANIPULATIONS 

Addressees:


All holders of operating licenses or construction permits for nuclear power 
reactors.

Purpose:

This information notice is intended to alert addressees to potential 
problems resulting from poor coordination between operations and maintenance 
personnel during valve testing and manipulations.  It is expected that 
recipients will review the information for applicability to their facilities 
and consider actions, as appropriate, to avoid similar problems.  However, 
suggestions contained in this information notice do not constitute NRC 
requirements; therefore, no specific action or written response is required.

Description of Circumstances:

During plant outages, plant personnel may perform many testing and 
maintenance activities concurrently.  Valve testing and manipulation, in 
particular, must be carefully coordinated so that system status is 
maintained for shutdown cooling accomplishing safety-related functions, and 
preventing inadvertent spills.  The following events demonstrate the 
importance of maintaining proper coordination between operations and 
maintenance personnel.

FARLEY UNIT 1--APRIL 24, 1991

During a refueling outage at the Joseph M. Farley Nuclear Plant, Unit 1, the 
licensee drained approximately 4500 gallons of water from the refueling 
water storage tank (RWST) to the containment sump by performing 
inappropriate valve manipulations.

A motor-operated valve testing team requested permission from the shift 
supervisor to test five valves associated with the containment sump.  The 
shift supervisor did not specify that the valves be tested one at a time.  
The valve testing team placed all five valves in midposition.  This action 
aligned a flow-path from the RWST to the containment sump.  The control room 
operators were notified of a spill in the containment sump and subsequently 
shut one of the valves in the flowpath.  Approximately 4500 gallons of water 
had spilled into the containment sump.


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QUAD CITIES UNIT 1--JANUARY 24, 1991

During a refueling outage, plant personnel opened (for maintenance) the 
shutdown cooling suction valve without appropriately notifying the 
operations department as required by the test plan being used.  This action 
initially resulted in losing five inches of coolant from the reactor vessel 
with some of the water exiting the reactor coolant system through open 
shutdown cooling vent and drain valves.  The vessel lost an additional nine 
inches of coolant when the shutdown cooling suction header refilled as it 
was restored to service.  Control room personnel did not expect the two 
sudden reductions in reactor vessel level. 

BRAIDWOOD UNIT 1--OCTOBER 4, 1990

During a maintenance outage, 620 gallons of coolant spilled as a result of 
improper valve sequencing because of poor coordination between the control 
room and auxiliary building personnel.  This spill contaminated three 
individuals and burned one of them.

A valve testing team reported to the control room that a seat leak test was 
complete on the residual heat removal (RHR) suction isolation valve from the 
hot leg of the reactor coolant system (RCS).  The team also reported that 
they were shutting the vent valve used for this test.  Without receiving 
positive confirmation that the vent valve was closed, the control room 
personnel opened the RHR suction isolation valve from the RCS hot leg for 
stroke time testing.  This action aligned the RCS to the open vent valve, 
which caused a measuring tube to break loose and spray the three test 
personnel.  The control room personnel then shut the same valve to stop the 
spill.  The coolant level in the pressurizer decreased approximately five 
percent during this event. 

FOREIGN REACTOR EVENT--FALL 1990

During a refueling outage, RHR was lost for 46 minutes and the temperature 
of the reactor coolant increased 30 degrees C.  This event occurred because 
a suction valve in the RHR system was unintentionally shut without valve 
indication in the control room and without the operators knowing when the 
work activities involved would take place. 

Initially, RHR train B was aligned to transfer water from the refueling 
water storage tank to the refueling cavity.  When the refueling cavity 
reached the desired water level, the operators attempted to restore the 
normal RHR train B lineup.  When the B train RHR pump was started, operators 
noticed signs of cavitation and secured it.  RHR train A was unavailable 
because of electrical maintenance.  Operators attempted to restore both RHR 
trains to service.  They determined that the problem with RHR train B was a 
RHR pump suction isolation valve that had jammed shut.  They subsequently 
pried the valve open to restore the RHR flowpath.  The utility investigated 
the incident and found that the valve motor was incorrectly continuously 
energized with temporary power.  The 

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temporary power was supposed to provide remote operability and indication 
for the valve, but the electrical contractor mistakenly connected the 
temporary power directly to the valve motor.

Discussion:

All of these events involved poor coordination and/or errors during valve 
testing and manipulations.  These events illustrate the importance in main-
taining proper control over the operation of valves during outages when many 
testing and maintenance activities may be occurring simultaneously.

This information notice requires no specific action or written response.  If 
you have any questions about the information in this notice, please contact 
one of the technical contacts listed below or the appropriate NRR project 
manager.




                                 Charles E. Rossi, Director
                                 Division of Operational Events Assessment
                                 Office of Nuclear Reactor Regulation


Technical Contacts:  David L. Gamberoni, NRR
                     (301) 492-1171
                
                     Donald Kirkpatrick, NRR
                     (301) 492-1176


Attachment:  List of Recently Issued NRC Information Notices
                                  
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