LD-89-051, Provides Comments on Generic Ltr 88-20, Individual Plant Exam for Severe Accident Vulnerabilities - 10CFR50.54(f) & Draft NUREG-1335, Individual Plant Exam: Submittal Guidance Dtd Jan 1989

Provides Comments on Generic Ltr 88-20, Individual Plant Exam for Severe Accident Vulnerabilities - 10CFR50.54(f) & Draft NUREG-1335, Individual Plant Exam: Submittal Guidance Dtd Jan 1989

ML20246N504
Person / Time
Site:	Davis Besse
Issue date:	03/16/1989
From:	Shelton D TOLEDO EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
RTR-NUREG-1335 GL-88-20, NLD-89-05165, NLD-89-5165, NUDOCS 8903270390
Download: ML20246N504 (3)

Text

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h- TOLEDO I %mm EDISON A Centenor Energy Company DONALD C. SHELTON vo.%o nsuo,

{419]2494300 1

NLD-89-05165 March 16, 1989 United. States Nuclear Regulatory Commission Document Control Desk Washington,.D. C. 20555 Subjects Comments on Generic Letter Number 88-20 and Draft NUREG-1335 Related to Individual Plant Examinations Gentlemen:

Toledo Edison (TE) herewith provides the attached comments on Generic Letter Number 88-20, " Individual Plant Examination for Severe Accident Vulnerabilities - 10 CFR 50.54(f)," dated November 23, 1988 (Log Number 2775) and draft NUREG-1335, " Individual Plant Examination: Submittal Guidance",

dated January 1989 (Log Number 2834). A portion of these. comments were previously informally provided at the Individual Plant Examination (IPE)

Vorkshop conducted on February 28 - March 2, 1989.

If you have any questions concerning this matter, please contact Mr. R. V.

Schrauder, Nuclear Licensing Manager, at (419) 249-2366.

Very truly yours, l RMC/dlm Attachment cc: _ P. H. Byron, DB-1 NRC Resident Inspector 6 A. B. Davis, Regiona-1 Administrator, NRC Region III T. V. Vambach, DB-1 NRC Senior Project Manager 8903270390 890316 N PDR ADOCK 05000346 d P PNU W I, THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OHIO 43652

                                        'NLD-89-05165
                  *'I' ' March 16, 1989:                                                                                                                                                                                                                                                                d i

Attachment Page 1 COMMENTS ON GENERIC LETTER NUMBER 88-20 AND NUREG-1335 Ag Requirements for "back-end" analysis

1. The overall requirements are still not very clear. Is it required that Level 2 based risk ranking be established for containment failure, or that only the failure modes and phenomena be studied?

2. What is an acceptable " Template Approach"? Is it a comparative analysis with some limited scope of analyses in physical process, source term and containment structure? Guidelines are needed regarding this approach.

3. Without knowing the more defined requirements and/or guidelines, it is very difficult for utilities to predict the scope and schedule for the IPE proposal.

4. There are sequences that result in the release of primary coolant to the containment without core damage (non-core melt sequences) followed by release to the environment through the bypass of containment. These sequences could be high frequency, but have low consequences (i.e., some source term). Should the "back-end" analysis include these non-core melt sequences?. Also, should non-core release (e.g.,.vaste gas tank, spent fuel) be considered?

B. Requirement for Direct Involvement by Utility Personnel

1. Personnel most familiar with the detail of design controls, procedures, and system configurations are the design engineers and plant operators. It is very difficult to directly involve these personnel in the IPE process on a consistent basis because of the problems of availability (conflicts with current assignments) and their primary responsibilities. These people can be best utilized for review of results, operator actions, data, etc.

C. Dependent Failures

1. This is another area of great uncertainty. There are concerns over the validity of current techniques, beta values (i.e.,

NUREG/CR-4780 and EPRI-NP-5613), etc. The results of previous studies are inconsistent with operating experience. Further guidelines are needed on the beta values before the IPE results involving common-cause can be used. D. Containment Performance Improvement (CPI) Program

1. Toledo Edison encourages early NRC staff completion of the CPI program intended to compliment the IPE program in order to minimize impact on the utilities' IPE plans and their implementation.

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           , .NLD-89-05165                                                                           l
    .-*-       March 16,'1989
              . Attachment Page 2                                                                               l l                   :E.,' General                                                                    ;

1. What is the definition of core damage for IPE7 Is it core melt or fuel clad damage, or is it the 10CFR50.46 (b) criteria?

2. Should high energy line breaks (HELB) be included as an event initiator?

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3. How'is, equipment survivability to be handled in the severe '

accident environment?- Guidelines should be provided.

4. It would be beneficial if guidance would be provided with respect to the anticipated NRC plans for IPE applications.and its I maintenance. This may influence the manner in which plants define f their IPE programs,. set up organization staff, organize d

                             . documentation, etc.

5. The NRC estimate of 8100 person-hour for performance' of the IPE l (dollar estimate of $500,000 per "NRC' Staff Evaluation in Support i of 10CFR50.54(f) Generic Letter Requiring Individual Plant Examinations at Nuclear Power Plants", dated December 1, 1988'-(Log Number-2812)) is very low based on other manpower estimates for a Level 1 PRA as presented in'NUREG/CR-2300.

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