United States Nuclear Regulatory Commission - Protecting People and the Environment

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. 
.

                                    - 2 -

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 Monday, June 17, 2013