United States Nuclear Regulatory Commission - Protecting People and the Environment

Audit of Small Break LOCA Guidelines (Generic Letter 79-68)



GL79068 

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

                                   December 17, 1979 

TO LICENSEES OF ALL OPERATING NUCLEAR POWER PLANTS 

Gentlemen: 

SUBJECT: AUDIT OF SMALL BREAK LOCA GUIDELINES 

The Bulletins & Orders Task Force has now approved the small break loss of 
coolant accident guidelines for essentially all operating plants. As 
discussed in our letter of September 13, 1979 to the licensees of all 
operating nuclear power plants, licensees are to prepare emergency 
procedures and complete the associated training of operators by December 31, 
1979. 

As part of this program, members of the Bulletins and Orders Task Force plan
to audit the program of selected utilities to assure that the implementation
of the respective programs for incorporating the revised procedures are 
acceptable. The plants which the Bulletins and Orders Task Force will visit 
and the schedule are as follows: 

               Westinghouse Plants 

               Salem 1                  December 10, 1979 
               North Anna 1             December 19, 1979 
               Haddam Neck              December 20, 1979 

               Combustion Engineering Plants 

               Millstone 2              December 19, 1979 

               General Electric Plants 

               Nine Mile Point 1        December 10, 1979 
               Fitzpatrick              December 11, 1979 
               Dresden 2 & 3            December 12, 1979 

The programs for those plants which are not audited by the Bulletins and 
Orders Task Force will be audited by representatives of the Office of 
Inspection and Enforcement. 

                                                                  8001070 
.

                                   -2-

To help assure that these audits are effective and efficient for both the 
licensees and the staff we have developed the enclosed audit plan. This 
audit plan will be used by both the Bulletins and Orders Task Force and the 
Office of Inspection and Enforcement in conducting the audits. 

If you require any clarification of the matters discussed herein please 
contact the assigned Operating Reactors Project Manager for your plant. 

                                        Sincerely, 


                                        Darrell Eisenhut, Acting Director 
                                        Division of Operating Reactors 

Enclosure: 
As stated 

 cc: See attached lists 
.

                                                                Enclosure 

                   AUDIT OF SMALL BREAK LOCA PROCEDURES 

1. Comparison to Guidelines 

The NRC staff will coffipare the small break procedure to the guidelines 
approved for the plant type. In addition to checking against the specific 
line items (actions and precautions) in the guideline, the NRC staff will 
consider the clarity of the procedure, in terms of individual actions and 
precautions, and flow of the procedure with respect to timely initiation of 
all operator actions. 

The licensee should have personnel familiar with the development of the 
small break LOCA procedure available to answer NRC staff questions about 
omissions and ambiguities in the procedure. The utility should explain the 
process by which the approved guidelines were converted into operating 
procedures includinq, the results of internal review, problem areas, and 
plant specific information required in the procedure. 

2. Training 

The NRC staff will review the training the reactor operators received in  
the small break LOCA procedure. We expect this training to include formal 
classroom study and a walk thru of the procedure with the shift supervisor 
or training coordinator. 

The licensee should have the training coordinator available to discuss the 
training with the NRC staff. 

3. Operator Feedback 

A member of the Operator Licensing Branch or an IE Inspector will audit 
several operators to determine the adequacy of the procedure from a 
.

                                   -2-

functional standpoint and the effectiveness of the training program. The 
audit, which is oral, will cover understanding of small break LOCA, differ-
erntiation between LOCAs and other depressurization events, familiarity with
the smll break LOCA procedures, basis for the revised procedures, and 
whether the procedures can be effectively carried out. 

The licensee should have several operators available, including senior 
operators who can be questioned by the staff. 

4. Systems Considerations 

The NRC staff will review system-related aspects of the procedure to assure 
that the operawr actions can be performed. These systems considerations will
vary with plant type as noted in Table 1. 

The licensee should have technical personnel and documentation available 
(including P&ID of ECCS) to respond to NRC staff questions on system 
considerations in the procedure. 
.

                                   -3-

Westinghouse 

a)   Instrumentation - Certain instrumentation is used by the operator in 
     the procedure to initiate actions such as HPI temination and switchover 
     from injection to recirculation. The licensee should show that the 
     instrumentation used as part of this procedure will provide adequate 
     information for performing operator actions considering instrument 
     uncertainty, environmental conditions at the time it is required, and 
     power (with loss of offsite power and a single failure). 
     
b)   Reactor Coolant Pump Trip - The licensee should show that the primary 
     system pressure at which he trips the reactor coolant pumps in his 
     procedure is consistent with the prescription in the guideline's. 

c)   Manual Switchover - For those plants which rely on the operator to 
     perfom a portion or all of the switchover from injection to 
     recirculation, the licensee should show that this action can be 
     performed before the RWST water level reaches an unacceptable level. A 
     time sequence table should be available showing procedure steps, flow 
     out of the RWST, volume of water reinaining in the RWST, and time 
     required to perform each step as a function of time. Maximum ECCS and 
     containment spray flow should be used to develop the sequence table. 

d)   HPI Protection After Switchover - For those plants that have HPI pumps 
     with 1400-1500 psi shut off heads, the licensee should show how the 
     prpcedures will preclude damage to those pumps after switchover to 
     recirculation from the sump for break sizes that would result in 
     deadheading the pumps after switchover. Under these conditions, the 
     procedures should also provide instructions for maintaining adequate 
     pressure level inventory  
.

                                   -4-

     after switchover. 

e.   Bulletin Items - The licensee should show how he has incorporated his 
     responses to the I&E bulletins (issued in April 1979) in his procedure 
     with respect to: 

     Containment Isolation 
     PORV Indication 
     Transfer of Fluids Out of Containment 
     Hydrogen Gas 
.

                                   -5-

Combustion Engineering 

a)   Instrumentation - Certain instrumentation is used by the operator in 
     the procedure to initiate actions such as HPI termination and 
     switchover from injection to recirculation. The licensee should show 
     that the instrumentation used as part of this procedure will provlde 
     adequate information for performing operator actions considering 
     instrument uncertainty, environmental conditions at the time it is 
     required, and power (with loss of offsite rower and a single failure). 
     
b)   HPI Protection After Switchover - For those plants that have HPI pumps 
     with 1400-1500 psi shut off heads, the licensee should show how the 
     procedures will preclude damage to those pumps after switchover to 
     recirculation from the sump for break sizes that would result in 
     deadheading the pumps after switchover. Under these conditions, the 
     procedures should also provide instructions for maintaing adequate 
     pressure level inventory after switchover. 

c)   Bulletin Items - The licensee should show how he has incorporated his 
     responses to the I&E bulletins (issued in April 1979) in his procedure 
     with respect to: 

     Containment Isolation  
     PORV Indication 
     Transfer of Fluids Out of Containment 
     Hydrogen Gas 

                                                                     (OVER) 
.

                                   -6-

General Electric 

a)   Instrumentation - Certain instrumentation is used by the operator in 
     the procedure to initiate actions such as HPI termination and 
     switchover from injection to recirculation. The licensee should show 
     that the instrumentation used as part of this procedure will provide 
     adequate information for performing operator actions considering 
     instrument uncertainty, environmental conditions at the time it is 
     required, and power (with loss of offsite power and a single failure). 
     
b)   Bulletin Items - This licensee should show how he has incorporated his 
     responses to the I&E bulletins (issued in April 1979) in his procedure 
     with respect to: 

     Containnment Isolation 
     Transfer of Fluids Out of Containment 
     Hydrogen Gas 
.

                           OPERATING LICENSE 

                        Pressurized Water Reactors 

                              50-003/247 
                              50-029 
                              50-206 
                              50-213 
                              50-244  
                              50-250/251  
                              50-255  
                              50-260  
                              50-261  
                              50-266/301  
                              50-269/270/287  
                              50-272  
                              50-280/281  
                              50-282/306  
                              50-285  
                              50-286  
                              50-289/320  
                              50-295/304 
                              50-302 
                              50-305  
                              50-309  
                              50-312  
                              50-313/368  
                              50-315/316  
                              50-317/318  
                              50-321    
                              50-334  
                              50-335  
                              50-336  
                              50-338  
                              50-344  
                              50-346  
                              50-348 
.

                          OPERATING LICENSE   

                          Boiling Water Reactors 

                              50-010/237/249 
     
                              50-133   

                              50-755   

                              50-219   

                              50-220   

                              50-245    

                              50-254/265   

                              50-259/296   

                              50-263   

                              50-271   

                              50-277/278   

                              50-293   

                              50-298   

                              50-325/324   

                              50-331   

                              50-333   

                              50-366 

                              50-409 

Page Last Reviewed/Updated Wednesday, May 22, 2013