Review of the Emergency Planning Sensitivity Project Title: Study for Seabrook b. Objective The objective of this effort is to assist the NRC in evaluating the technical validity of the applicant's conclusions regarding the Emergency Planning Sensitivity study for Seabrook. 2. SUMMARY OF PRIOR EFFORTS A review of the Containment Failure Modes and Radiological Source Terme presented in the Seabrook Station Probabilistic Safety Assessment was performed by BNL under FIN A-3778. However, this review did not evaluate in detail the containment performance under severe accident conditions. Nevertheless, the experience gained by BNL staff under FIN A-3778 will provide useful background for the current review of the Emergency Planning Sensitivity Study for Seabrook. 3. WORK TO BE PERFORMED AND EXPECTED RESULTS Work Requirements Task 1: System Evaluation BAL will review those portions of the Seabrook Emergency Planning Sensitivity Study related to system failure to determine the appropriateness of the calculated accident sequence probabilities. In particular, the probability for interfacing system LOCA will be carefully assessed to determine the potential for containment bypass. BNL will also review the probability of equipment malfunctions, personnel errors, and design errors resulting in containment bypass at the time of a severe accident. Estimated Level of Effort: Estimated Completion Date: (FY 86) 2 Professional Staff Months (pam) October 31, 1986 Task 2: Containment Event Tree Review BNL will review the conditional probabilities of early containment failure given in the Seabrook submittals. In particular, the vulnerability of the Seabrook containment to uncertainties in containment loads will be carefully assessed. This task will be highly coupled to Task 3, which will assess the performance of the Saabrook containment under severe accident conditions. The purpose of this task is to evaluate the technical validity of the applicant's conclusions regarding the behavior of the Seabrook containment under severe accident conditions. (See Continuation Sheet) BNL will review and evaluate the relevant contaḍment structural analyses performed by the applicant and its consultants. In addition, a plant site tour and engineering audit at the applicant's (or consultant's) office will be conducted to better understand the containment analyses and design and to identify any unique design features and/or analytical assumptions that merit further investigation. Based on the above review, BNL will develop an axisymmetric finite element model and perform analyses utilizing BNL's NFAP computer code to confirm the applicant's prediction of the overall capacity of the containment. Special attention will be given to the post-cracking behavior of the concrete which controls the shear failure mode of the containment. To expedite the performance of this task, BNL will utilise, to the maximum extent practical, the input parameters obtained from the applicant's analytical models. In addition, simplified hand calculations will be performed to assess the applicant's conclusions regarding the behavior of selected containment penetration assemblies. Finally, BNL will perform a qualitative assessment of the applicant's seismic fragility analysis of the containment structures, and components. BNL will also support meetings with upper NRC management and the ACRS to describe the interim status of this review, as well as the final results. The appropriateness of the new source terms based on RSS methodology used in the Seabrook submittal will be reviewed. Estimated Level of Effort: (FY 86) 1 pen Estimated Completion Date: September 30, 1986. - Task 5: Site Consequence Modeling The site consequence modeling will be reviewed to determine the appropriateness of the consequence calculations presented in the Seabrook submittal. In addition, any consequence calculations found necessary as a result of the work to be performed under Tasks 1 - 4 will be performed. Estimated Level of Effort: Estimated Completion Date: (FY 86) 1 pam (See Continuation Sheet) Review of the Emergency Planning Sensitivity Project Title: Study for Seabrook 3. WORK TO BE PERFORMED AND EXPECTED RESULTS (Cont.) Task 6: Report Preparation and Follow-on Effort 5. In addition, A final report will be prepared based on the results of Tasks 1 any follow-on effort in terms of resolution of issues will be provided under this task. The final report will be issued on 12/31/86 and will address 3NL's recommendations on procedures, testing or design modifications, to reduce the probability of containment bypass in conjunction with a severe accident. Estimated Level of Effort: (FT 87) 2.5 pam Estimated Completion Date: September 30, 1987 Level of Effort and Performance The estimated total level of effort is 19 professional staff-months over a period of 14 months. b. Meetings and Travel It is expected that there will be two trips, one to the Seabrook plant site and one to UE and C'a offices in Philadelphia, PA, for three BNL engineers each lasting 2-3 days. In addition, three one-day meetings in Washington, DC are anticipated. One meeting may require 6 BNL engineers, the other two will require 2 BNL engineers. C. NRC Furnished Materials NRC will provide all documents prepared by the applicant or its consultants which are to be reviewed by BNL. 4. DESCRIPTION OF ANY FOLLOW-ON EFFORTS Not applicable. 5. RELATIONSHIP TO OTHER PROJECTS BNL has ongoing efforts for MRR/NRC in the area of severe accident analysis and risk assessment. These include peer review of plant-specific, industry-sponsored probabilistic risk assessments. To date BNL has reviewed various aspects of the follow ing PRAS: Big Rock Point, Indian Point, Zion, Limerick, GESSAR, Shoreham, Oconee-3, Millstone-3, and Seabrook. BNL also has ongoing efforts for RES/KRC dealing with severe core damage, fission product release and transport to the environment. In particular, BNL will verify the Source Term Code Package and the calculations to be performed as part of the updating by SARP of nuclear accident risk (MUREG-1150). In addition, BNL staff are evaluating uncertainties in source term estimates (FIN A-3286). Finally, BNL staff are providing assistance to the NRC staff in developing a technical basis for offsite emergency preparedness under PIN A-3268. (Sea Continuation Sheet) ! Review of the Emergency Planning Sensitivity Project Title: Study for Seabrook 6. REPORTING REQUIREMENTS Technical Reports Six copies of all technical reports which are required for the program shall be submitted to the NRC Project Manager. Business Letter Reports P. 7 A monthly business letter report will be submitted by the 20th of the month to Mr. Goutam Bagchi, NRC Project Manager, with copies provided to the Director, Division of PWR Licensing A, Attn: D. Fiorvante and M. Kaltman, NRR. The report will iden tify the title of the project, the FIN, the Principal Investigator, the period of performance, and the reporting period and will contain 2 sections as follows: Project Status Section 1) A listing of efforts completed during the period, milestones reached, 2) Any problems or delays encountered or anticipated and recommendations 4) A brief summary of plans for the next reporting period. b. Financial Status Section BNL will provide the personnel time expenditures and the amount of funds expended (costed) by category during the period and total cumulative year-to-date as follows: Review of the Emergency Planning Sensitivity Project Title: Study for Seabrook 7. SUBCONTRACTOR INFORMATION BNL does not intend to subcontract any portion of this work. In the event a subcontract is anticipated, BNL will notify MRC before it is initiated. 8. NEW CAPITAL EQUIPMENT REQUIRED None. 9. SPECIAL FACILITIES REQUIRED Mone. 10. CONFLICT OF INTEREST INFORMATION There are neither significant contractual nor organizational relationships of the Department of Energy, BNL and employees, or expected subcontractors or consultante on this proposal, with industries regulated by the NRC and suppliers thereof that give rise to an apparent or actual conflict of interest. 11. EXPECTED CLASSIFICATION OR SENSITIVITY This is an unclassified program. Safeguards, proprietary, or other sensitive information is not involved. |