Information Notice No. 91-77: Shift Staffing at Nuclear Power Plants

                                UNITED STATES
                          WASHINGTON, D.C.  20555 

                             November 26, 1991 



All holders of operating licenses or construction permits for nuclear power 


The U.S. Nuclear Regulatory Commission (NRC) is issuing this information 
notice to alert addressees to problems that could result from inadequate 
controls to ensure that shift staffing is sufficient to accomplish all 
necessary functions required by an event.  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 are not NRC requirements; 
therefore, no specific action or written response is required. 

Description of Circumstances 

On April 29, 1991, the Maine Yankee Atomic Power Plant experienced a main 
generator hydrogen fire.  Although a senior reactor operator (SRO) and 
auxiliary operators from another shift were available immediately, the need 
to provide personnel for the fire brigade and yet perform the many actions 
required by the event caused a heavy workload for the control room staff.  
This workload contributed to the licensee's failure to notify some key 
emergency response personnel as specified in the licensee's procedure.  

On June 15, 1991, at 11:50 p.m., lightning struck the switchyard at the 
Yankee-Rowe Nuclear Power Station.  The lightning strike caused a fire, a 
loss of offsite power, a loss of normal telephone communication, and a 
reactor trip.  The staff on duty experienced difficulty in its effort to 
concurrently classify the event, notify the required people, implement 
emergency operating procedures, and provide personnel for the fire brigade.  
The lack of staff contributed to the licensee's failure to make a timely 
Notification of Unusual Event to the State of Vermont and to the 
Commonwealth of Massachusetts.  Two auxiliary operators, members of the five 
man fire brigade, did not respond to the fire because they were needed to 
start the steam driven emergency boiler feed pump.  After the plant was 
initially stabilized, the shift supervisor sent the shift technical advisor 
to the central alarm station to report the plant's status to the plant 
manager via the loss-of-power telephone.  This was done because their first 
attempts to report by the control room phones were unsuccessful.


                                                       IN 91-77 
                                                       November 26, 1991 
                                                       Page 2 of 2 


The safe operation of a nuclear power plant and the preservation of the 
health and safety of the public depend on the ability of the on duty staff 
to respond to an event.  The number of staff on each shift is expected to be 
sufficient to accomplish all necessary actions to ensure a safe shutdown of 
the reactor following an event.  Those actions include implementing 
emergency operating procedures, performing required notifications, 
establishing and maintaining communications with the NRC and plant 
management, and any additional duties assigned by the licensee's 
administrative controls.  Many licensees assign control room staff to be 
members of the fire brigade.  Also, the operations staff is frequently 
required to support special security responses such as plant searches in 
response to a bomb threat.  Section 50.54(m) of Title 10 of the Code of 
Federal Regulations addresses only minimum staffing levels for licensed 
personnel and does not address personnel availability for performing all of 
the necessary actions specified in the licensee's administrative controls 
and required by an event.  Licensees may wish to carefully review actual 
staffing needs to ensure that sufficient personnel are available to 
adequately respond to all events.  This is especially relevant to the 
backshift when staffing levels are usually at a minimum. 

Related Generic Communications 

1.   NUREG-0737, "TMI Action Plan," dated October 30, 1980.

2.   NRC Generic Letter 82-16, "NUREG 0737 Technical Specifications," dated 
     September 20, 1982.

3.   NRC Generic Letter 83-02, "NUREG 0737 Technical Specifications," dated 
     January 10, 1983. 

This information notice requires no specific action or written response.  If 
you have any questions about the information in this notice, please contact 
the technical contact listed below or the appropriate Office of Nuclear 
Reactor Regulation (NRR) project manager. 

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

Technical contact:  Jesse Arildsen, NRR 
                    (301) 492-1026 

Attachment:  List of Recently Issued NRC Information Notices

Page Last Reviewed/Updated Wednesday, March 24, 2021