Emergency Procedures and Training for Station Blackout Events (Generic Letter 81-04)
UNITED STATES
NUCLEAR REGULATORY COMMISSION
WASHINGTON D.C. 20555
February 25, 1981
TO ALL LICENSEES OF OPERATING NUCLEAR POWER REACTORS AND APPLICANTS FOR
OPERATING LICENSES (EXCEPT FOR ST. LUCIE UNIT NOS. 1 & 2)
SUBJECT: EMERGENCY PORCEDURES AND TRAINING FOR STATION BLACKOUT EVENTS
(Generic Letter 81-04)
A recent decision by the Atomic Safety and Licensing Appeal Board (ALAB-603)
concluded that station blackout (i.e., loss of all offsite and onsite AC
power) should be considered a design basis event for St. Lucis Unit No. 2.
An amendment to the Construction Permit for St. Lucis Unit No. 2 was
subsequently issued on September 18, 1980. The NRC staff is currently
assessing station blackout events on a generic basis (Unresolved Safety
Issue A-44). The results of this study, which is scheduled to be completed
in 1982, will identify the extent to which design provisions should be
included to reduce the potential for or consequences of a station blackout
event.
However, the Board we recommended that more immediate measures be taken to
ensure that station blackout events can be accommodated while task A-44 is
being conducted. Although we believe that, qualitatively, there appears to
be sufficient time available following a station blackout event to restore
AC power, we are not sure if licensees have adequately prepared their
operators to act during a station blackout event.
Consequently, we request that you review your current plant operations to
determine your capability to mitigate a station blackout event and promptly
implement, as necessary, emergency procedures and a training program for
station blackout events. Your review of procedures and training should
consider, but not be limited to:
a. The actions necessary and equipment available to maintain the reactor
coolant inventory and heat removal with only DC power avaliable,
including consideration of the unavailability of auxiliary systems such
as ventilation and component cooling.
b. The estimated time available to restore AC power and its basis.
c. The actions for restoring offsite AC power in the event of a loss of
the grid.
d. The actiond for restoring offsite AC power when its loss is due to
postulated onsite equipment failures.
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e. The actiones necessary to restore emergency onsite AC power. The
actions required to restart diesel generators should include
consideration of loading sequence and the unavailability of AC power.
f. Consideration of the availibility of emergency lighting, and any
actions required to provide such lighting, in equipment areas where
operator or maintenance actions may be necessary.
g. Precautions to prevent equipment damage during the return to normal
operating conditions following restoration of AC power. For example,
the limitations and operating sequence requiremnts which must be
followed to restart the reactor coolant pumps following an extended
loss of seal injection water should be considered in the recovery
procedures.
The annual requalification training porgram should be consider the emergency
procedures and include simulator exercises involving the postulated loss of
all AC power with decay heat removal being accomplished by natural
circulation and the steam-driven auxiliary feedwater system for PWR plants,
and by the steam-driven RCIC and/or HPCI and the safety-relief values in BWR
plants.
We conclude that the actions described above should be completes as soon as
they reasonably can be (i.e., within 6 months). In addtion, so that we may
determine whether your license should be amended to incorporate this
requirement, you are requested, pursuant to SS50.54(f), to furnish within
ninty (90) days of receipt of this letter, an assessment of your existing or
planned facility procedures and training programs with respect to the
matters described above. Please refer to this letter in your response. In
the event that completion within 6 months can not be met, please propose a
revised date and justification for the delay.
This request for information was approved by GAO under a blanket clearance
number R0072 which expires November 30, 1983. Comments on burden and
duplication may be directed to the U.S. General Accounting Office,
Regulatory Reports Review, Room 5106, 441 G Street, NW., Washington, D.C.
20548.
Sincerely,
Darrell G. Eisnhut, Director
Division of Licensing
Office of Nuclear Reactor Regulation
Page Last Reviewed/Updated Tuesday, March 09, 2021