United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 83-35: Fuel Movement with Control Rods Withdrawn at BWRS

                                                            SSINS No.: 6835 
                                                            IN 83-35       

                                UNITED STATES
                            WASHINGTON, DC 20555
                                May 31, 1983

                                   AT BWRS 


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


This information notice is provided as a notification of potentially 
significant events involving fuel loading in control cell locations where 
control rods are not fully inserted. It is expected that recipients will 
review the information for applicability to their facilities. No specific 
action or response is required at this time. 


Brunswick 1 Event 

During a refueling outage on Saturday, January 22, 1983, five control rods 
in empty cell locations were uncoupled from their drive mechanisms to permit 
removal of the drives for maintenance. As work progressed, the rod drives 
were recoupled with the control rods because of pressure fluctuations in the
rod drive fluid, thereby preventing the removal of the drive mechanisms from
the reactor vessel. To avoid having a maintenance crew idle, a decision was 
made to proceed to other control rod drives requiring maintenance. 

By 3:00 a.m, on January 23, the shift foreman, after consultation with the 
nuclear engineer on shift, concluded that all applicable requirements had 
been met for a temporary change to the existing fuel movement procedure. The
shift operating supervisor and the senior reactor operator on the refueling 
bridge approved the temporary change to bypass some steps in the existing 
procedure and proceed to the next 4 control cells requiring rod drive 
maintenance. Each of the 4 control cells contained a fuel assembly. These 
assemblies were subsequently moved to 4 other separate control cell 
locations according to the fuel movement procedure. 

During a routine rod position verification, approximately 9 hours after the 
4 fuel assemblies were moved, it was discovered that the control rods in 
those cells were fully withdrawn. As mentioned above, the fuel movements 
were made in accordance with the as-written fuel movement procedure, but 
apparently were not reviewed to ensure that the control rods were fully 
inserted in those cells to which fuel was moved. These fuel movements were 
in violation of the licensee's technical specifications. 


                                                            IN 83-35    
                                                            May 31, 1983 
                                                            Page 2 of 3 

Duane Arnold Event 

During core loading operations on March 30, 1980, a fuel assembly would not 
set properly in its assigned location in control cell, 06-19. A temporary 
change was written to the fuel movement procedure to unload inspect, and 
reload that control cell. Upon completion of the steps to the change of the 
fuel movement procedure, the normal reload was resumed beginning with 
control cell 06-23. The first fuel assembly was moved into control cell 
06-23. Before a second fuel assembly could be loaded into control cell 
06-23, it was discovered that the control rod in that cell was not fully 
inserted. Inadvertently, the fuel movement procedure temporary change had 
eliminated a step to insert the control rod in the next cell (06-23) to be 
loaded. This fuel movement was in violation of the licensee's technical 


Refueling interlocks are specified for all BWRs to prohibit fuel loading 
with any control rod withdrawn in order to prevent the possibility of 
criticality during refueling operations. Operating plant technical 
specifications have, however, allowed bypass of the refueling interlock 
signals to facilitate multiple control rod drive maintenance. The bypass of 
the refueling interlock signals was acceptable as long as several criteria 
were met, including the removal of the fuel assemblies surrounding the 
control rod to be withdrawn. Some technical specifications then evolved 
through utility negotiations with the NRC to permit fuel loading with 
control rods withdrawn. Subsequently the NRC issued the BWR Standard 
Technical Specifications (NUREG-0123) which reflected this position. 
Brunswick 1 operates under essentially standard technical specifications; 
Duane Arnold operates under custom technical specifications. Both versions 
allow fuel movement with multiple control rods withdrawn when specific 
conditions are met. 

General Electric recognized the potential problem in June 1982 and issued 
SIL No. 372 to clarify the original intent of the GE BWR technical 
specifications concerning refueling interlocks. It was recognized at this 
time that the potential for localized criticality and fuel damage does exist
while loading fuel with control rods withdrawn for maintenance. General 
Electric recommended that each licensee review its present technical 
specifications and refuel and rod drive maintenance procedures and adopt the
concept of suspended fuel loading whenever all control rods are not fully 

The original intent of the refueling interlocks is to prohibit the loading 
of fuel assemblies into the reactor vessel with multiple control rods 
withdrawn. Some operating plant technical specifications do not allow fuel 
loading in the reactor vessel with control rods withdrawn for maintenance 
and other plants may want to reflect this position in their station 
procedures. The NRC plans to reevaluate the Standard Technical 
Specifications governing fuel movement with multiple control rods withdrawn 
for maintenance. 

                                                            IN 83-35    
                                                            May 31, 1983 
                                                            Page 3 of 3 

No written response to this information notice is required. If you need 
additional information regarding this matter, please contact 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:  P. R. Farron
                    (301) 492-4766

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