NRC Generic Letter 1983-31

NRC Generic Letter 1983-031: Safety Evaluation of Abnormal Transient Operating Guidelines.

ML031210067
Person / Time
Site:	Oconee
Issue date:	09/19/1983
From:	Eisenhut D G Office of Nuclear Reactor Regulation
To:
References
GL-83-031, NUDOCS 8309190017
Download: ML031210067 (2)

v-. anSeptember 19, 1983TO ALL OPERATING REACTOR LICENSEES, APPLICANTS FOR AN OPERATING LICENSEAND HOLDERS OF CONSTRUCTION PERMITS FOR BABCOCK & WILCOX PRESSURIZEDWATER REACTORSGentlemen:

SUBJECT: SAFETY EVALUATION OF "ABNORMAL TRANSIENT OPERATING GUIDELINES"(GENERIC LETTER 83-31)The NRC staff has reviewed the proposed Oconee Nuclear Station, Unit 3Abnormal Transient Operating Guidelines (ATOG) as described in Babcock &Wilcox (B&W) Owners Group letters dated March 31, 1982 and June 15, 1982,and D. Napiors letter from B&W to the Owners Group dated March 14, 1983.As discussed in the enclosed letter to the B&W Owners Group we have con-cluded that ATOG is acceptable as a basis for implementation of improvedplant specific procedures and will provide improved guidance for operatoremergency procedures over that which currently exists. Since there is nogeneric version of ATOG for B&W plants, the utilities who are participatingin the Owners Group program are to provide sufficient documentation in theform of plant-specific ATOGs and Transient Information Documents (TIDs) sothat the NRC can perform comparisons with the ATOG version evaluated in theenclosed Safety Evaluation Report (SER). We suggest that implementation ofthe guidelines proceed in 4 steps:(1) Interim extension of ATOG to better cover ATWS and certain aspectsof natural circulation;(2) Preparation of plant specific procedures which, in general, conformto the ATOG referenced above and implementation of these proceduresas required by Generic Letter 82-33, dated December 17, 1982;(3) Preparation of supplements to the guidelines which cover changes, newequipment, or new knowledge and incorporation of these supplementsinto the procedures; and(4) Completion and improvement of the guidelines to meet our long termrequirements, followed by incorporation of improvements into plantspecific procedures.Step 1 is to be completed before ATOG is used in the implementation ofprocedures process. The prompt implementation of Step 2 will allow thebenefits of the significant improvements you have achieved to be realizedsoon. We note however, that the guidelines are written for the procedurewriters, not control room operators, and therefore, preparation and830190 '5Ef~Jt-2 Lf-Fl8309190017

-2 -September 19, 1983implementation of procedures will require additional Human Factors input.Step 3 refers to a program for guideline or procedure updates which will begenerated as a matter of routine after the implementation. This essentiallyis a maintenance function. Step 4 refers to a program for addressing thoseaspects of the guidelines and procedures where additional long term work maybe needed in your emergency procedure program.We have identified in the Safety Evaluation Report (SER) a number of itemsassociated with the guidelines which need further work by the B&W Owners.We require that these items be addressed by either incorporating them intoa future guideline revision or otherwise justifying the disposition of theitem. The Owners Group letter of May 4, 1983 provided a satisfactory out-line of a plan to change the existing ATOG to a more generic document. Weshare the Owners Group judgement that a B&W generic technical guidelinewill provide an effective mechanism for future guideline updates, changesand enhancements. Additionally, because the Abnormal Transient OperatingGuidelines must be dynamic in that changes must be made to reflect changesin equipment or new knowledge, we expect the B&W Owners' Group or a similarcoalition of utilities and vendors to accept responsibility for continuedmaintenance of the guidelines. Therefore, we have requested in the enclosedletter that the B&W Owners' Group provide a plan for addressing the SERitems and a description of the program for steps 3 and 4 above.As discussed in the enclosed SER, the staff finds that ATOG represents asignificant improvement over the guidance provided in current emergencyoperating procedures. ATOG is symptom oriented, considers multiple failures,is tolerant of operator error, addresses plant cooldown following anemergency, and addresses inadequate core cooling. We find the approachused in ATOG to be responsive to the staff's criteria. Further, ATOGcontains a significant quantity of valuable information for the guidance ofoperators under emergency conditions. The guidelines provide sufficientguidance such that they can be translated into acceptable emergency operatingprocedures using the process identified in NUREG-0899, "Guidelines for thePreparation of Emergency Operating Procedures." The staff therefore con-cludes that although efforts to improve the guidelines should continue,ATOG will provide a greater assurance of operational safety and are accept-able for implementation.

Sincerely,Darrell G. Eisenhut, DirectorDivision of Licensing

Enclosures:

'1. Letter to Mr. Whitney,dated2 SER n GuidelinesDL: i#5 DL:Q D j 'SA t DL R DJL oI:cc DCrui hfield F ,1i aI, /83 1/ 83 3 83