ML25197A069
| ML25197A069 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 09/17/1975 |
| From: | Kerr W Advisory Committee on Reactor Safeguards |
| To: | Anders W NRC/Chairman |
| References | |
| Download: ML25197A069 (1) | |
Text
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS NUCLEAR REGULATORY COMMISSION WASHINGTON. D. C. 20555 September 17, 1975 Honorable William A. Anders Olairman
- u. s. Nuclear Regulatory Commission washington, D. C. 20555 SUbject:
REPORl' 00 THE CALIAWAY PIANT UNITS l and 2
Dear Mr. Anders:
During its 185th meeting, September 11-13, 1975, the Advisory Committee on Reactor Safeguards reviewed the application of the Union Electric Company for a permit to construct the Callaway Plant Units 1 and 2. '!he site of the proposed plant was visited on August 20, 1975, and Subcorrmittee meetings were held on August 19, 1975, in Washington, D. c., and on August 20, 1975, in St. I.ouis, Missouri. During its review, the Committee had the benefit of dis-cussions with the Nuclear Regulatory Commission (NRC) Staff and representatives and consultants of the applicant, the westinghouse Electric Corporation and the Bechtel Corporation. 'lbe Conmittee also had the benefit of the documents listed below.
'!he ca11away Plant application is one of four submitted in response to the Cornmission's standardization policy as described in Appendix N of Part 50 of Title 10 of the Code of Federal Regula-tions. 'Ibis option allows for simultaneous review of the safety-related parameters of a limited mnnber of duplicate plants which are to be constructed within a limited time span at a multiplicity of sites.
'lbe other sites are located in Kansas, Wisconsin, and New York. '!he five utilities that have joined together have designated their carm:>n design the "Standardized Nuclear Unit Power Plant Systern° (SNUPPS).
'!he Conmittee believes that its report on the callaway application, as discussed below, also is a report on the SNOPPS design to the extent practical.
'lbe callaway Plant will be located in a rural section of callaway County about 80 miles west of St. I.ouis, Missouri on a tract of land five miles north of and about 300 feet above the Missouri River. '!be exclusion area radius of 1,200 meters is within the site property limits. '!he nearest center of population is Jefferson City (popula-tion 32,400) 25 miles west-southwest.
196
Honorable William September 17, 1975
'!he Callaway Plant will utilize two four-loop pressurized water reactor nuclear steam supply systems, each having a power level of 3411 MW{t) and a design similar to that of the Comanche Peak Steam Electric Station Units 1 & 2 previously reported on by the Conmittee in its letter of <x:tober 18, 1974. '!he turbine gener:ator is supplied by the General Electric Company and will be oriented S'o as to mini-mize damage from turbine failure.
'!he ultimate heat sink for the plant will consist of two four-cell mechanical draft cooling towers with a source of makeup water from an onsite retention pond. 'lhese cooling towers and the cut slopes of the retention pond will be seismic category I. '!he pond will be sized to provide sufficient makeup water for 30 days with the reactors shut down.
'!he analyses of the response of the plant to the postulated loss-of-coolant accidents as required by the Final Acceptance Criteria are tmderway but not yet fully completed. '!he applicant is committed to the evaluation of a full spectrtnn of postulated break sizes prior to the issuance of a construction permit.
He discussed what was stated to be a worst case in which he found that the criteria were satisfied. '!he Conmittee wishes to be kept infoaned concerning the resolution of this matter.
'!he Committee recormrended in its report of September 10, 1973, on acceptance criteria for ECCS, that significantly improved ECCS capability should be provided for reactors for which construction permit requests are filed after January 7, 1972. '!he SNUPPS design is in this category.
'lhese tmits will use the 17xl7 fuel assemblies similar to those to be used in Comanche Peak Steam Electric Station Units 1 & 2. Although calculated peak clad temperatures in the event of a postulated I..(x:A are less for 17xl7 assemblies than for a 15xl5 array, the Committee believes that the applicant should continue sttrlies that are responsive to the Cornmitttee's September 10, 1973 report. If studies establish that significant further ECCS improvements can be achieved, considera-tion should be given to incorporating them into these tmits.
In conjunction with his presentation of results of analyses of events subsequent to a postulated loss-of-coolant accident, the applicant discussed the developnent of best-estimate calculations for the same class of accidents. His preliminary results indicated that a consid-erable margin of safety may exist; however, the methodology used has not been subjected to critical evaluation. 'Ihe Committee recognizes the potential importance of sttrlies of this type in the improvement and optimization of design of safety devices and encourages the applicant and the NRC Staff to accelerate their efforts to this end.
'!he Committee wishes to be kept infoaned.
197
li>norable William September 17, 1975 Each of the SNOPPS units employs a cylindrical, steel-lined, reinforced, post tensioned concrete containment structure with a free volume of about 2. Sxl0 6 ft 3 *
'!he design pressure is 60 PSIG at a temperature of 320 degrees Fahrenheit. '!he design will conform to the proposed ACI-ASME Concrete Containment Code (Section III, Division 2 of the ASME B:>iler and Unfired Pressure vessel Code) with appropriate modi-fications required by.the NRC Staff. '!he Committee believes that this containment design with the auxiliary systems (sprays, heat removal, air cleaning, and combustible gas control) is satisfactory for the SNOPPS design at the callaway site.
'!be Callaway Plant will be the first conmercial nuclear power plant in the State of Missouri. For this reason, the Conmittee recomnends that the applicant and the Regulatory Staff give particular attention to assuring proper coordination with appropriate state agencies in the develo:pnent of effective emergency plans for this facility.
'!he Conmittee believes that the applicant and the NRC staff should continue to review the callaway Plant design for features that could reduce.the possibility and consequences of sabotage.
'!he Conmittee recomends that the NRC staff and the Applicant review the design features that are intended to prevent the occurrence of damaging fires and to minimize the consequences to safety-related equipnent should a fire occur. 'Ibis matter should be resolved to the satisfaction of the NRC Staff. '!he Conmittee wishes to be kept informed.
Generic problems relating to large water reactors are discussed in the Comnittee's report dated March 12, 1975. 'lhese problems should be dealt with appropriately by the NRC Staff and the applicant.
'!he Advisory Conmittee on Reactor Safeguards believes that the items mentioned above can be resolved during construction and that, if due consideration is given to the foregoing, the callaway plant Units 1 and 2 can be constructed with reasonable assurance that they can be operated without undue risk to the health and safety of the public.
Additional remarks by Dr. H. s. Isbin are attached.
Sincerely yours,
- w. Kerr Olairman 198 September 17, 1975 Additional Remarks by H. S. Isbin In my opinion, a significant omission in the SNOPPS Preliminary Safety Analysis Report is section 1.5, Requirements for Further
'lechnical Information.
An important contribution that the SNCJPPS project can make is to note the many experimental and analytical studies mderway that serve to better define the margins of safety, that serve to confirm design methods, that contribute to the reso-lution of generic items, that relate to improved reliability of components and systems, and that seek to advance surveillance and monitoring systems. A thorough compilation of such activities would be a reflection of industry's overall commitments to a better mder-standing of safety issues and advancing of safety measures. '!he material provided in section 1. 5 of the PSAR should not be construed to be licensing requirements. A rrore appropriate accounting of licensing requirements should be through the NRC Staff's Safety Evaluation Report where the Staff should compile into a single section all items identified in their review which require the submission of future information.
'!he SNUPPS project represents a very substantial and unique concentration of industry effort in the developnent of nuclear reactor power stations. I believe that it is appropriate for SNUPPS to develop a meaningful Section 1.5 which could serve as a reference for other applications.
199 September 17, 1975 References
- 1. SNUPPS Preliminary Safety Analysis Report with Revisions 1 through 9 and the Callaway Site Addendum Report with Revisions 1 through
- 5.
- 2.
RESAR-3 Consolidated Version, ~stinghouse Reference Safety Analysis Report with Arnendnents 1 through 6.
- 3. Safety Evaluation Report, NUR00-75/076 related to the construction of Callaway Plant, Units 1 & 2, Docket Nos. STN 50-483 & S'IN 50-486, August, 1975.
- 4.
Report on Field & Laboratory Investigation of Crushed Stone Fill, Callaway Plant, Units 1 & 2, for Union Electric Company, Dames &
Moore Job No. 7677-074-07 August 8, 1975.
- 5. Report on the Second Year of 01-Site Meteorological Monitoring Program and the Comparison of the First and Second Year of fleteorological Data Union Electric Company, callaway Plant, Units 1 & 2, Dames & Moore, Job No. 7677-056-07, July 15, 1975.
- 6. Union Electric Company letter dated September 5, 1975, from John K.
Bryan to Bernard C. Rusche, Director, Office of Nuclear Reactor Regulation, USNRC, Ser UI.NRC-121, SUbject: Submittal of prelimi-nary analysis of the Ultimate Heat Sink.
200