United States Nuclear Regulatory Commission - Protecting People and the Environment

NUREG-0737, Item I.C.l, Abnormal Transient Operator Guidelines (ATOG) (Generic Letter No. 81-16)



                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                          WASHINGTON, D. C. 20555 

                                June 1, 1981 

TO ALL B&W LICENSEES (Except Arkansas Nuclear One, Unit One) 

Gentlemen: 

SUBJECT:  NUREG-0737, ITEM I.C.1, ABNORMAL TRANSIENT OPERATOR GUIDELINES 
          (ATOG) (Generic Letter No. 81-16.) 

The staff has completed a preliminary review of the ATOG prepared for 
Arkansas Nuclear One Unit One and submitted as generic guidelines in 
response to NUREG-0737, Clarification of TMI Action Plan Requirements, Item 
I.C.1. We have identified the following deficiencies in areas that were 
identified in NUREG-0737, but are not addressed by the ATOG submittal: 

1.   The bases for the consideration of multiple and consequential failures 
     is not provided. The sequence-of-event diagrams are not complete (i.e.,
     ATWS following an initiating event). 

2.   Supporting analyses for multiple failures are not presented for all 
     cases. The description of the computer programs used to analyze the 
     events is not provided. 

3.   Operator errors of omission or commission are not addressed. 

4.   The following multiple failure events are not addressed: 

     (a)  SG tube rupture in more than one steam generator; 
     (b)  Failure of the high-pressure reactor coolant makeup system; 
     (c)  ATWS following an initiating event (with or without a turbine 
          trip); and 
     (d)  Failure of main and auxiliary feedwater with partial or complete 
          loss of HPI. 

5.   The transition from emergency procedures into an adequate core cooling 
     (ICC) procedure is not developed or included. (We understand that B&W 
     is incorporating ICC into the ATOG program for some future submittal.) 

Since you have referenced this report as applicable to your facility, please
advise us within 30 days of your receipt of this letter of your schedule for
response to these items and the impact this will have on your schedule for 
implementing a program of emergency operating procedures that comply with 
the requirements of NUREG-0737, Item I.C.1. 
.

All B&W Licensees Except             -2- 
ANO-1  

Since the responses required by this letter affect fewer than 10 licensees 
and are required to obtain a benefit, they are not subject to Office of 
Management and Budget clearance as required by P.L. 96- 511. 

                              Sincerely, 


                              Thomas M. Novak, Assistant Director 
                                for Operating Reactors 
                              Division of Licensing 
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