Information Notice No. 91-77: Shift Staffing at Nuclear Power Plants
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555
November 26, 1991
NRC INFORMATION NOTICE 91-77: SHIFT STAFFING AT NUCLEAR POWER PLANTS
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.
November 26, 1991
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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
Attachment: List of Recently Issued NRC Information Notices
Page Last Reviewed/Updated Wednesday, March 24, 2021