ML19261B974
| ML19261B974 | |
| Person / Time | |
|---|---|
| Site: | Clinch River |
| Issue date: | 03/05/1979 |
| From: | Caffey L ENERGY, DEPT. OF, CLINCH RIVER BREEDER REACTOR PLANT |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7903090226 | |
| Download: ML19261B974 (18) | |
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Department of Energy Clinch River Breeder Reactor Plant Project Office P.O. Box U Oak Ridge, Tennessee 37830 Docket No. 50-537 File: 05.10 March 5,1979 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Conmission Washington, DC 20555
Dear Mr. Denton:
PROJECT EVALUATION OF THE NRC STAFF REVIEW 0F CRBRP
References:
(1) Letter, L. W. Caffey to R. S. Boyd, "CRBRP Licensing Status," dated January 3, 1979.
(2) Letter, W. P. Gammill to L. W. Caffey, dated Novem-ber 9, 1978.
(3) Letter, L. W. Caffey to R. S. Boyd, "CRBRP Licensing Emphasis," dated May 5,1977.
(4) Letter, L. W. Caffey to R. S. Boyd, "CRBRP Licensing Status," dated July 22, 1977.
In Reference (1) we related that we were evaluating the Staff positions expressed in Reference (2) and would be advising you subsequently of our plan for further progress on the design and of our assessment of the resolvability of open items. This letter is our follow-on to Refer-ence (1).
Enclosure 1 is an item-by-item statement of our assessment of the resolvability of each of the items presented in the NRC Staff Review of CRBRP of Reference (2). Since NRC's suspension of its safety review of Project documentation, the Project has continued to provide PSAR updates and other design information that the NRC Staff had not taken into consideration in preparing Reference (2). We believe that this additional documentation provides the bases for resolution of many items and that the continuation of the Project during this fiscal year points up the need for supportive technical interchange with the NRC Staff. (
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Mr. Harold R. Denton 2 March 5, 1979 In general, our evaluation of the NRC Staff Review has led us to separate the open items into three groups. We have placed each item into one of the groups. Group 1 consists of items which we believe can be resolved readily by NRC Staff review of information it now has. Group 2 consists of items for which we must provide further information in order to provide a fuller basis for resolution. Group 3 consists of items for which we sense a strong need for interaction between the Project and the NRC Staff to obtain clarification of Staff views so that we can be more certain of the effectiveness of our development and design actions toward resolution.
We are obliged to continue apace with our design and component fabrica-tion. The further we proceed without techr
- cal exchange with the NRC Staff, the greater grows the likelihood Gat for lack of concurrent Staff review, this Project would not be in a position to move forward rapidly to the start of construction if such a positioning we"e to be the result of the current debate over the Project's future.
From the aspect of discontinuance of the Project, if that should be the end result, there are several unresolved items considered to be generic to the overall LMFBR program, which is continuing. These need to be mutually identified and their resolution needs to be pursued timely for the benefit of the greater program. The FY 80 budget as submitted to Congress contemplates that such issues would be addressed in context of the CRBRP design. Please see the attached extract from the Department of Energy FY 80 Congressional Budget Request, Volume 2, Eneroy Supply, Research and Development, January 1979 (Enclosure 2).
It is requested that the NRC Staff resume its safety review and tech-nical interchange activities, as requested previously in References (3) and (4). At the least, we should be working with you in regard to items which are generic to the overall LMFBR program. An early response would be appreciated.
Sincerely, f ,
- ochlin L W. Caffey, Direc PS:79:054 Clinch River Breeder Reactor Plant Project Office
Enclosures:
As stated cc: Service List Standard Distribution Licensing Cistribution
Enclosure 1 3/5/79 PROJECT EVALUATION OF ITEMS OF THE "NRC STAFF REVIEW 0F CRBRP" Each of the items addressed in the NRC Staff Review of CRBRP has been analyzed and evaluated by the CRBRP Project Staff. The results of the evaluation are presented below in the same formTt and order used in the NRC Staff Paview.
I. GENERAL A. Control Room Design Conformance with CRBRP Criterion 17
- 1. The NRC Staff identified an open item concerning the adequacy of systems to limit radiation doses to control room personnel for the site suitability source term specified by the NRC Staff and for events associated with core melt. The radiological analysis assuming the site
- oitability source term has been completed and the results will be included in PSAR Section 6.3 in an April 1979 amendment. Radiological analyses for the hypothetical core melt will be provided later this year in a topical report CRBRP-3, Vol. 2, " Hypothetical Core Disruptive Accident Considerations in CRBRP; Assessment of Thermal Margins Beyond the Design Base." The Project believes these submittals will provide an adequate basis for the NRC and Project agreement on this item. (Group 2)
- 2. The NRC Staff stated its concern for the capability for remote control of the reactor. Revised PSAR Section 3.1.3.1 and Section 7.9.7 provided, in Amendment No. 32, functional requirements for this remote control (Remote Shutdown System) which ara believed to satisfy the remote reactor control requirements of NRC and CRBRP Design Criteria 17. (Group 1)
- 8. Large Sodium Releases in Steam Generator Building (SGB)
- 1. The NRC Staff i entified a need for additional information to understand and evaluate the models ard assumptions used in CRBRP's analyses of large sodium fires in the SGB. The PSAR design description and accident analyses sections are currently being updated co provide the requested information and will be provided later this year to facilitate the NRC review. (Group 2)
- 2. The NRC Staff indicated that they must assess the adequacy of the proposed fire suppression and nitrogen flooding systems for sodium fires in the SG Building. The sodium fire protection system relies on catch pans with fire suppression decks augmented by support equipment. We believe that sufficient information for the NRC to evalu-ate the sodium fire rotection systems is described in PSAR Section 9.13.2, which will be supplemented in a May 1979 amendment to the PSAR. (Group 2)
2 C. Implementation of Design Criteria The tiRC Staff issued design criteria and safety classification guidelines in January 1976. These have been adopted by the Project ar.d were provided in PSAR Sections 3.1 and 3.2 in Amer.dment Nos. 32 and 26, respectively. (Group 1)
D. Operator Licensing The NRC Staff requires compliance with Regulatory Guide 1.33 or an acceptable alternate. The Project comitted to meet Regulatory Guide 1.33 in the response to NRC Question 412.3 in Amendment No.13 to the PSAR. (Group 1)
E. Safeguards The NRC Staff stated that the Applicant must revise the PSAR to reflect the spirit and intent of the new requirements (10 CFR 73.55, issued in February 1977) and that the Staff must assess the susceptibility of principal design features to sabotage. The new requiremnts promulgated in 10 CFR 73.55, February 1977, on safeguards have been incorporated in Sec-tions 9.11 nd 13.7 of the PSAR by Amendment No. 47. (Group 1)
F. Erergency Planning The NRC Staff requested time-distance-dose relationships for the CRBRP vicinity in order to further review the low population zone and the scope of specific emergency planning measures.
The requested infomation was provided for NRC review in the response to NRC Question 422.1 and Section 15-A of the PSAR by Amendment No. 40. (Group 1)
G. Quality Assurance and Operations The NRC Staff states that it finds the CRBRP QA program accept-able subject to (1) receipt of an adequate QA program for fuel and blanket assemblies, and (2) a list of structures, systems, and components under the control of the QA program. The fiRC also states that its review of the QA program is complete through PSAR Amendment No. 38. Amendment No. 40 provided Appendix 17B which is the QA program for the fuel and blar.ket assembly supplier. PSAR Amendment No. 40, Section 17.0.5, references the applicable safety-related structures, systems, and components described in Sections 3.2 and 7.1. (Group 1)
H. Foundation Engineering The NRC Staff stated that neither the Staff nor their consultants have completed their review of matters relating to foundation engineering including subsurface solution cavities, quality control and assurance programs for Class "A" fill and backfill,
3 dynamic lateral earth pressures on subsurface walls, and evaluation of foundation conditions encountered during excavation.
Additional information has been provided to the NRC in PSAR Section 2.5 and the response to NRC Question 324.11 in Amend-ment Nos. 35 and 38. (Group 1)
I. Geology-Seismology The NRC Staff indicated that further Staff review of investi-gations addressing the possible existence of unidentified linears in the vicinity of the proposed CRBRP site is required.
Additional information intended to satisfy NRC concerns was provided by the ERDA/P0 letter, A. R. Buhl to R. S. Boyd, PS:L:77:797, dated August 29, 1977. (Group 1)
J. Meteorology The NRC Staff expressed concern with the correlation of wind and temperature difference data measured at the 75 and 33 foot levels and the very low frequency of calm wind occurrences as compared to other data at the CRBRP site and at other sites.
Additional wind data has been taken at the 33 foot level for the required period of one year. This additional information, which the Project believes to meet NRC accuracy guidelines, was provided in PSAR Section 2.3A in Amendment No. 43. (Group 1)
II. CONTAINMENT SYSTEM DESIGN A. Large Sodium Releases and Design Basis Accidents The NRC Staff expressed concern that the containment DBA selected by the Project is not appropriately conservative and that features provided to mitigate a hypothetical core melt can perform their functions effectively in the hostile environ-ment.
The Project has specified a DBA for the containment which it believes to be conservative in that it includes assumptions that the largest available sodium volume spills into an air-filled cell and that 100% of the oxygen in containment is consumed bl; combustion with the spilled sodium. The Project has inclucea features to ensure protection for this event. In addition, the Project has committed to prudently mitigate the results of hypothetical accidents beyond the design basis.
The Project will qualify required equipment to the hostile environments as will be discussed in a report to be submitted later this year. Technical interactions are necessary to precisely define the HRC questions in these areas. (Group 3)
4 B. Accommodation of Energetics The Project believes that further technical interactions are necessary with respect to the energetics. The Project has submitted on February 9,1979, the report CRBRP-3, Vol.1,
" Hypothetical Core Disruptive Accident Considerations in CRBRP; Energetics and Structural Margin Beyond the Design Base," which provides the current information related to the analytical and experimental bases for specification of ener-getics, the analyses supporting the design capability to withstand these, and the results of the supporting SRI tests.
The Project requests that a meeting be scheduled to initiate discussions in this area following the NRC Staff review of this additional material. (Group 3)
C. Accomodation of Melt-Down The Project is currently completing compilation of a report which comprehensively addresses the total area of accomoda-tion of melt-down phenomena including consideration of the current experimental data. The concerns expressed by NRC will be addressed in this report which will be submitted to NRC later this year. The intent is to provide a comprehensive and coherent description of the accomodation of core melt.
(Group 2)
D. Accomodation of Site Suitability Source Tem The NRC Staff indicated that a detailed review of information in this area has not been completed but, based on a cursory review, the results appear to be in general agreement with those presented by the NRC Staff in the Site Suitability Report for CRBRP. The Project believes that detailed NRC Staff review will support its initial conclusion that the Project position and documentation (revised PSAR Chapter 15A submitted by Amendment No. 40) are acceptable. The Project provided the description of the filtration of the RSB in PSAR Section 6.2.6 in Amendment No. 36. (Group 1)
III. THERMAL-HYDRAULIC DESIGN A. Natural Circulation and Low Sodium Flows The NRC Staff has expressed concern with a design relying solely on natural circulation for decay heat removal. The addition of the diverse power supply for the pony motors increased the reliability of the forced circulation mode for decay heat removal. The design is such that decay heat removal can be accomplished by either forced or natural cir-cuiation. The Project, in response to NRC Question 001.580 in Amendment No. 32, comitted to analyses and testing which will confirm the natural circulation capabilitie; of CRBRP. The NRC Staff stated their review of the diverse power supply features has not been completed. (Group 1)
5 B. Hot Channel Factors The NRC Staff recommended tJ.at WARD-D-0050 and PSAR Section 4.4 be rewritten, with emphasis on the bases for the hot char.nel factors and on the statistical methods used. WARD-D-0050 has now been completed and will be submitted for NRC review upon completion of the appropriate PSAR Section 4.4 revision in August 1979. (Group 2)
C. Acceptability of Limits The NRC Staff noted that the Project's proposed use of no-sodium-boiling as a faulted condition limit is acceptable.
Other concerns regarding core thermal limits are addressed in Section VII of this document, " Fuel Design." The NRC Staff noted further review is required. (Group 1)
D. Loose Parts Monitoring The NRC Staff has stated in the CRBRP Site Suitability Report that the requirement for a loose parts monitoring system similar to those required for LWR's is anticipated and reiter-ated this in the Status Summary of Movember 9,1978. The Project is assessing the potential for and capabilities of such a system. This assessment will be completed by August 1979, at which time the Project will contact the NRC Staff to determine if further interaction is required. (Group 3)
IV. MECHANICAL / STRUCTURAL DESIGN A. Seismic Design On March 9, 1977, the Project met with the NRC Staff to discuss the seismic design of CRBRP. The meeting resulted in several questions. The Project has provided answers to satisfy these questions as indicated below: (Group 1)
- 1. Additional information concerning " Hybrid" foundation analyses was included in the response to NRC Question 130.53 and PSAR Section 3.7 in Amendment No. 40.
- 2. Documentation of changes to Tsai's weighted damping method was included in DOE /P0 letter PS:78:240, R.
Copeland to R. S. Boyd, dated September 1,1978.
- 3. Additional information on time increments and durations used in the analyses was included in D0E/P0 letter PS:78:240, R. Copeland to R. S. Boyd, dated September 1, 1978.
- 4. Details of the containment / confinement structure were included in ERDA/P0 letter PS:L:77:259, A. R. Buhl to R.
S. Boyd, dated May 10, 1977.
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- 5. Systems for which nonlinear analyses were used and additional details of this approach were included in D0F/P0 letter PS:78:240, R. Copeland to R. S. Boyd, dated September 1, 1978.
- 6. Additional information to clarify the method used in determining response ;?ectra is included in PSAR Sec-tion 3.7 and 3.9 in Amendment No. 46.
- 7. Clarification of the method used for soil-supported tanks is included in PSAR Sections 3.7 and 3.9 in Amendment No.
46.
- 8. Additional information concerning material degradation is included in DOE /PO letter, PS:78:240, R. L. Copeland to R. S. Boyd, dated September 1, 1978.
- 9. The method of accounting for the hydrodynamic and fluid coupling effects is included in PSAR Sections 3.7 and 3.9 in Amendment No. 46.
B. Dynamic and Static Analysis for Seismic Category I Components The apparent NRC Staff concern raised relates to receiving sufficient information to understand the methodology and criteria for the dynamic and static analyses for seismic Class 1 components. Tne Project has provided the information required for the Construction Permit review in conformance with the NRC Standard Format and Cortent in this area. Th!s material is in Sections 3.9, 5.3.3.1, 5.4.3.1. and 5.5.3.1 of the PSAR.
(Group 1) The remaining item. will be addressed in the FSAR as required by NRC's Standard Format and Content. (Group 2)
C. Control Rod Systems The NRC Staff states that it is not clear that the PSAR reflects the current design of tle secondary control rod drive cechanisms (SCRDM's). As a result of prototype testing of the SCRS, system design improvements are being incorporated into the design of the SCRS and will be documented in a PSAR amendment later this year. (Group 2)
D. Flow Induced Vibrations The NRC Staff has stated that the proposed program concept is reasonable and can be used to answer the adequacy of the CRBRP reactor internals subject to resolution of certain questions.
The Project has provided supplemental information in the response to NRC Question 110.67 and PSAR Section 3.9.1.3 in Amendment No. 43. The Project believes this supplemental information will provide the basis for resolution of these questions. (Group 1)
7 E. Load Combinations The NRC Staff has expressed concern with respect to the definition and manner of load combinations. The Project has committed to comply with the load combination requirements of ASME Section II'.
which NRC endersed in 10 CFR 50. The Project provided the additional requested information in Amendment Nos. 36, 44, and
- 46. (Group 1)
F. Pipe Whip Analysis The NRC Staff requested that the Project specify the pipe whip design criteria. The Project has provided this information in Section 3.6 of the PSAR in Amendment Nos. 34 and 45. (Group 1)
G. Snubbers The NRC Staff position is that the basis for the locations, required load capacity, and structural anc' mechanical perfor-mance parameters of safety-related snubbers must be provided.
The Project has provided information which addresses the NRC concerns. This information was included in the Piping Integ-rity Report (WARD-D-0185) in Amendment No. 42 of the PSAR.
(Group 1)
H. Active Pump and Valve Operability The NRC Staff requested that the Project provide a description of the types of analysis and/or testing, together with the loading conditions, to be used to verify the operability of active Class 1, 2, and 3 pumps and valves. The Project has provided details of the Active Pump and Valve Operability Progran in Sections 3.9 and 1.6 of the PSAR in Amendment No. 44. (Group 1)
I. Structural Design The NRC Staff stated that the Applicant must submit a mathe-matical model for the analysis of the cell liner and anchor system including the concrete in which the anchors are embedded.
The Project provided the requested information in PSAR Sec-tion 3A.8 in Amendment No. 45. (Group 1)
V. PIPING INTEGRITY The NRC Staff states that the double ended rupture of the PHTS need not be considered as a design basis event subject to the resolution of several concerns (size of leak, leak detection system, in-service inspection, and material surveillance). The NRC is also concerned related to the applicability of the conclusions to the hot leg.
8 The Project has addressed the questions raised related to the size of leak in the response to NRC Question 001.581; leak detection and the hot leg piping integrity in WARD-D-0185, " Integrity of Primary and Intermediate Heat Transport System Piping in Containment"; and material surveillance in PSAR Amendment Nos. 32, 40, and 42. As stated in the response to NRC Question 001.581, the Project has recommended using the moderate energy fluid system pipe break criteria for cell and cell liner design. The Project believes this information will provide the basis for resolution of these items.
The material presented in Appendix G to the PSAR represents the Project implementation of a practical inservice inspection program.
The hRC Staff has indicated concerns relating to Inservice Inspection; however, no specific comments or questions on Appendix G have been transmitted to the Project. (Group 1)
VI. ELECTRICAL A. Reactor Shutdown System (RSS)
The original information a' dressing the integrated design capability to satisfy the redundancy, diversity, and reli-ability requirements and the design criteria have been aug-mented in the following PSAR Sections and Tables: (Group 1)
Sections 4.2, 7.1, 7.2, 7.5, 7.7, 15.1, 15.2 Tables 15.2-1, 15.3-1, 15.1.3-3 Q/R's 222.13, 222.67, 001.313 B. Environmental and Seismic Qualification The NRC Staff concern is that the specific parameters to be used for environmental qualification have not been resolved.
In response, the Project has submitted WARD-D-0165, " Require-ments for Environmental Qualification of Class lE Equipment,"
in PSAR Amendment No. 47 which describes in detail the CRBRP environmental qualification program. The report includes specification of the parameters applicable to each item of Cl a s lE equipment. The Project believes that this submittal will provide the basis for resolution of tne NRC questions.
(Group 1)
C. Electrical Power System The NRC Staff stated that the Staff's review of recent changes to the electrical power system had not been completed and that questions relating to grid stability and other aspects had not been resolved. The Project provided information in PSAR Sections 8.2 and 8.3 as amended in Amendment No. 37. (Group 1)
9 D. Engineered Safety Features (ESF's)
The NRC Staff stated that review of the Project submittals pertaining to the electrical, instrumentation, and control systems associated with ESF's has not been completed. The Project believes that PSAR Chapters 7 and 8 provide the information necessary for NRC to complete its review. (Group 1)
E. Piping and Equipment Electrical Heating System The NRC Staff questioned whether the piping and equipment electrical heating system for safety-related systems is connected to a standby AC power supply. Analyses have shown that the plant can withstand the effects of the postulated SSE or loss of offsite power. Based on these analyses, the system temperatures remain significantly above the temperature at which trace heating is energized. Therefore, these systems are not necessary for protecting against these events and are not safety-related nor are the systems connected to standby AC power supplies. (Group 1)
VII. FUEL DESIGN The NRC Staff has expressed concern regarding the adequacy of the current experimental and analytical data available to support adoption of the fuel design limits specified by the Project.
The Project has supplied topical reports listed below which, .;ogether with the information presented in PSAR Section 4.2.1.3 and Table 4.3-5A, provide the information defining the current status and planning for these areas.
The NRC Staff acknowledges receipt of these topical reports and stated that they are judged amenable to post-CP review. The sub-mittal status of the eleven listed items is summarized below.
- 1. Fuel Densification PSAR Amendment 40, WARD-D-0168
- 2. Fuel Rod Bowing PSAR Amendment 30, WARD-D-0150
- 3. Fuel Rod Vibration PSAR Amendment 35, WARD-D-0166
- 4. Fuel Rod Wire Wrap PSAR Amendment 43, WARD-D-0149 Interaction
- 5. Fuel Assembly Structural Report to be submitted for Evaluation post-CP review
- 7. Fuel Rod Seismic Analysis PSAR Amendment 37, WARD-D-0158
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- 8. Internal / External Cladding PSAR Amendment 41, WARD-D-0147 Degradation
- 9. Fuel Restructuring Submittal to be made after completion of LIFE code verification
- 10. Fuel Rod Failure Criteria PSAR Amendment 27, no separate report
- 11. Exposure Dependent Claddiag PSAR Amendment 27, WARD-D-0146 Deformation The NRC Staff appears concerned that the Project is not including design provisions to detect fuel failure and prevent fuel failure propagation by appropriate responses to this detection.
The Project has design provisions to detect failed fuel including fission gas monitors, sodium sampling and analysis, and delayed neutron detectors in addition to the plant instrumentation. Based on current experimental and analytical data, fuel failures can be detected and appropriately characterized using these design provi-sions. Additionally, accident analyses are discussed in detail in PSAR Section 15.4 and the Project's response to fuel failure propa-gation concerns in a September 20, 1976, transmittal to the NRC.
The Project plans to remain cognizant of on-going R&D programs in this area to assure CRBRP safety design.
The responses to these detector signals and operating limitations will be established during the NRC Staff review of the final tech-nical specifications. The Project believes the above information will provide a basis for the NRC Staff to complete its review.
(Group 1)
VIII. SYSTEMS A. Fire Protection System The position issued by the NRC Staff stated that the Project should address the guidelines in Appendix A to Branch Technical Position APCSB 9.5-1. Since the initial release of Appendix A, the NRC has issued Regulatory Guide 1.120, Rev.1 (issued in November 1977), and BTP ASB 9.5-1, Rev.1 (issued in March 1978). The Project design was evaluated using these documents and has been revised to conform with the intent of the NRC guidelines. The NRC concerns will be resolved as individually addressed below: (Group 2)
- 1. A complete response to NRC Question 20.47 concerning the latest NRC fire protection requirements was provided in Amendment No. 48.
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- 2. The Project has made a preliminary determination of fire hazards which was submitted in Amendment No. 48. The Project will provide in the FSAR a detailed fire hazards analysis.
- 3. Information clarifying intermediate coolant system flam-mability and combustibility is currently included in PSAR Section 9.7 supplied in Amendment No. 44.
- 4. The listing of fire barriers in Table 9.13-1 have been updated and was supplied with Amendment No. 48. The ratings will be supplied as the design develops and the fire hazards analyses are conducted in each individual area.
- 5. The nitrogen flooding system has been deleted from the design. The P&ID's for the Halon and Carbon Dioxide Systems will be included in an August 1979 amendment to the PSAR.
- 6. The information concerning the assessment of sodium carbonate fire extinguisher suitability in liquid metal areas will be supplied in an August 1979 amendment to the PSAR.
B. Shutdown Heat Removal System The NRC Staff has stated that the Project responses to NRC positions regarding Shutdown Heat Removal are not acceptable.
The Project requests that a meeting be scheduled to discuss the NRC concerns in detail and determine the basis for reso-lution. (Group 3)
C. Reliability The NRC Staff has indicated that reliability activities may form part of the basis for revising the Staff position on decay heat removal.
The Project recommends that this potential use of reliability as well as other questions raised be discussed in the meeting requested in Item VIII.B. above to discuss the NRC decay heat removal concerns. (Group 3)
D. Effluent Treatment Systems The NRC Staff issued questions regarding proposed TLTM features on March 30, 1977. These questions will be specifically addressed in CRBRP-3, Vol. 2, " Hypothetical Core Disruptive Accident Considerations in CRBRP: Assessment of Thermal Margins Beyond the Design Basis" to be provided later this year. The report will include a comprehensive description of
12 the design features including the Containmant Cleanup System which filters and monitors the RCB atmosphere prior to release to the environment. (Group 2)
E. Steam Generator Tube Rupture The NRC Staff expressed concerns related to the adquacy of the codes used for analyzing the effects of ster..a generator tube ruptures and design features to mitigate he consequences resulting from the design basis accident.
The Project has continued to use the latest available infor-mation in the design of CRBRP including codes. ihe Project has and will continue to supply the latest information on these through PSAR updates.
The Project has documented the design of the SWRPRS, including rupture disc capability and the detailed design in PSAR Sec-tion 5.5 supplemented by Amendment No. 41.
The information above should provide the basis for agreement on the adequacy in the two identified areas. The Project believes this information will lead to agreement on the pro-posed steam generator design basis accident. (Group 1)
F. Steam Generator Auxiliary Heat Ramoval System The NRC Staff stated its position t'at the PWST should be sized to accommodate a 30-minute tine delay before operator action in the case of a feedwater pipe break. The PSAR states the PWST volume is based on operator action within 10 minutes in the event of a pipe break. This is a conservative estimate of the time required to perform the necessary remote manual actions--shutting off the valves at the main control board.
However, there is sufficient conservatism in the design of the Shutdown Heat Removal System and the PWST volume calculations that the Project can show that the PWST has sufficient water to accommodate an improbable longer wait for operator action after a pipe break. This will be documented in a PSAR amend-ment later this year. (Group 2)
G. Emergency Plant Service Water System (EPSWS)
The NRC Staff stated that the following information must be submitted for the Staff to complete its review of the EPSWS design. This information has been supplied. (Group 1)
- 1. A system flow diagram was provided in Figure 9.9-4 of the PSAR in Amendment No. 43.
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- 2. The volume of the EPSWS Expansion Tank and adequacy of the available water storage volume was requested. The Emergency Cooling Tower Basin, as described in PSAR Section 9.9 in Amendment No. 43, provides the system water storage capacity; the EPSWS Expansion Tank has been deleted.
- 3. Additional information regaising the heat duty and ade-quacy of the Airblast Heat Exchanger was requested. PSAR Section 9.9, provided by Amendment No. 43, fully describes the Emergency Cooling Towers which have replaced the Airblast Heat Exchangers as the ultimate heat sink for the EPSWS.
H. Compressed Air System The NRC Staff requested additional information on the Com-pressed Air System. The Project will provide the information in a PSAR amendment later this year. (Group 2)
I. Equipment and Floor Drainage System The NRC Staff concern is that the equipment and floor drainage system should be considered safety-related where backflew can cause flooding of safety-related areas. The Project will provide information in response to this concern in a PSAR amendment later this year. (Group 2)
J. Turbine Missiles The NRC Staff stated that additional information regarding the turbine design is required for the Staff to complete its review of potentially damaging turbine failures. This informa-tion was provided by DOE /P0 letter, PS:L:77:882, A. R. Buhl to
- 1. S. Boyd, dated October 27, 1977, and incorporated by reference,
" Hypothetical Turbine Missile Data and Probability of Occurrence for 3600-RPM-23-Inch LSB Unit for Use With the Liquid Metal Cooled Fast Breeder Reactor," in PSAR Section 1.6 by knendment No. 42. (Group 1)
IX. ACCIDENT ANALYSIS (RADIOLOGICAL)
A. Continuous Containment Purge The NRC Staff has stated that adequately conservative assess-ments of the spectrum of design basis accidents must be developed to consider the Project's purge concept acceptable. The Project has provided the definition of design basis events and the supporting analyses to the NRC in Amendment Nos. 30, 36, and 45 to the PSAR. The Project needs further clarification of the NRC concerns. The Project requests a meeting be scheduled to discuss this item. (Group 3)
14 B. Open Hatch Refueling The NRC Staff concerns relate to the accidents considered during refueling and means to control the consequences. The Project has included a confinement capability in the RSB. The confinement capability (discussed in PSAR Sections 9.6.3 and 6.2.6 in Amendment No. 36) further reduces potential offsite consequences of postulated accidents during refueling.
(Group 1)
C. Steam Generator Tube Failures The NRC Staff concern relates to the potential for release of primary sodium to the environment through a particular sequence.
The design does not depend solely on the integrity of the IHX to prevent such releases. The Plant design precludes the direct driving of primary sodium to the steam generator and atmosphere through this postulated scenario of IHX tube leak coupled with steam generator tube rupture. PSAR Seccion 15.7.1.3 discusses an IHX tube leak event. PSAR Section 15.7.1.3.5 outlines the CRBRP intermediate system design to preclude the event of primary sodium leakage to the steam generator system.
(Group 1)
D. Sodium Fires The NRC Staff is concerned with mitigation of sodium fires in the steam generator building, specifically with regard to offsite consequences. As indicated in Item I.B., the plant features that mitigate SGB sodium fires will be clarified in an amendment to the PSAR to be provided later this year. The amendment will also provide updated analysis of design basis fires, including assessment of offsite consequences. (Group 2)
E. RAPS Surge Vessel The NRC Staff stated the initially proposed design criteria provided insufficient control of the consequences of a Surge Vessel rupture. The RAPS surge vessel has since been relo-cated to inside the RCB, which is a controlled leakage envi-ronment. The Project has provided accident analysis and descriptions in the response to NRC Ouestion 310.48 and in PSAR Section 15.7.2 in Amendment No. 36. (Group 1)
F. Cold Trap Fires The NRC Staff expressed concern regarding the radiological consequences of a postulated cold trap fire. Additional information in the form of analysis was requested in NRC Question 310.49. The Project has provided such analysis in the response to NRC Question 310.49 in Amendment No. 45.
(Group 1)
. 15 G. Instrumentation to Follow the Course of an Accident
- 1. The NRC Staff ' dicates tiat it has not completed its review of the instruments provided for Post Accident Monitoring (PAM). The information required for the NRC review is provided in revised PSAR Chapter 7 and in WARD-0-0165, " Requirements for Environmental Qualification of Class lE Equipment" in Amendment Nos. 23 and 47. (Group 1)
- 2. The NRC Staff is concerned that appropriate instruments do not appear to be provided for following the course of the hypothetical event. The Project intends to provide instrumentation such that the plant operators will have sufficient information to make the appropriate decisions with respect to initiation of TMBDB features. The instrumentation will be discussed in CRBRP-3, Vol. 2,
" Hypothetical Core Disruptive Accident Considerations in CRBRP: Assessment of Thermal Margins Beyond the Design Base" to be provided later this year. (Group 2)
H. Risks Associated with Nearby Industrial Activities The NRC Staff stated that additional information was needed about potential impacts to the CRBRP from accidents at the proposed Exxon facility. The Project has followed the activ-ities of the proposed Exxon facility which recently has not been active in its application for a construction permit. If more information becomes available from renewed construction permit activities regarding the Exxon facility, additional information will be submitted. (Group 1)
Enclosure 2
.. e Energy Supply Research and Development - Operating Energy Supply Research and Development - Plant and Capital Equipr.ent Nuclear ,
(Tabular dollars in thousands, Narrative naterial in whole dollars. )
Clinch river breeder reactor project $172,400 $ 0 The 1.dministration has proposed that the CRBRP Project at Oak Ridge, Tennessee be discontinued except for selected design, component and generic licensing activities of value to the overall IyeFER program. It is the Administration's objective that appropriate legislation for discontinuance be enacted as early as possible. The FY 1980 budget request does not therefore, include funding for CRBRP, recognizing that CRERP discontinuance could still be authorized and funded in appropriate FY 1979 legislation. If such legislation were enacted, currently available funding which is being expended at the rate of
$16,000,000 per conth, could be made available for discontinuance expenses.
In the event that CRBRP discontinuance is not authorized until well into the fiscal year, additional FY 1980 funding for this purome, over and aboie the funding requested herein could be required.
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