ML25196A409
| ML25196A409 | |
| Person / Time | |
|---|---|
| Issue date: | 06/11/1976 |
| From: | Moeller D Advisory Committee on Reactor Safeguards |
| To: | Rowden M NRC/Chairman |
| References | |
| Download: ML25196A409 (1) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON, D. C. 20555 Honorable Marcus A. Rowden Chairman U.S. Nuclear Regulatory Ccmnission washington, DC 20555 June 11, 1976.
SUbject:
REroRl' CE SWESSAR-Pl, $'IONE AND WEB.STER QGINEERIK; CX>RPORATICE BALANCE-OF-PIANT OF.SIGN AS APPLIED 'IO ClH30S'l'ICE EH;INEERIR;,
ig:_ CFSSAR-80
Dear Mr. a:
,wden:
At its 194th meeting, on June 3-5, 1976, the Advisory Ccmnittee on Reactor safeguards reviewed the application of the Stone and Webster Engineering Corporation for a Preliminary Design Approval of its SWESSAR-Pl, a stand-ardized nuclear balance-of-plant (BOP) design*that.would interface with a single unit Combustion Engineering, Inc. CF.SSAR-80 pressurized-water-nuclear steam supply system (NSSS). A similar review for a Westinghouse RESAR-41 design was conducted at the 190th meeting of the COnmittee and was discussed in its report of February 11, 1976. '!he description of SWESSAR-Pl provided in the February 11, 1976 report is applicable to OSSAR-80: the latter was reviewed and a report provided by the Ccmnittee on September 17, 1975. During its review, the COmnittee had the benefit-of*
discussions with representatives of the Stone and Webster Engineering Corporation and the Nuclear Regulatory Comnission (NRC) Staff. '!he Ccm-mittee also had the benefit of the documents listed.
flie arrangement of SWESSAR-Pl provides extensive physical separation of critical safety-related equipnent to protect against CODm)n mde failures associated with fires or other operational contingencies. However, can-plete design details for SWESSAR-Pl have not been developed and the concept has not yet been applied to a conplete nuclear power plant*deslgn. Con-sequently, further review of the physical separation arrangement should be made prior to the Final Design Approval or when SWF.SSAR-Pl is proposed for a nuclear -power plant for which a construction pemit is being sought.
flie Comnittee wishes to be kept informed.
A matter of major concern in the NRC Staff's review has been the safety-related interfaces between the SWESSAR-Pl BOP design and the CF.SSAR-80 NSSS design, on one hand, and the custan-designed site-related structures and components, on the other hand. '!he responsibilities and requirements related to the SWESSAR-Pl/CF.SSAR-BQ interfaces have been partially defined 3569
Honorable Marcus A. !Dden J'une 11, 1976 in the Safety Analysis Reports for these two standardized designs. 'ffle can-mittee believes that these interface requirements are satisfactory for a Preliminary Design Approv~, but expects the NRC Staff and the Applicant to continue to examine them further in connection with the proposal to use these designs.for an actual plant when it is reviewed for a construction permit. '!be interfaces between SWESSAR-Pl *and the site-related features are defined in the SWESSAR-Pl Safety Analysis Report, but have not yet been subjected to the test of a canplete design for a nuclear power plant. '!be NRC Staff should review these interfaces in greater depth when a construction permit application is received.
ttie carmittee reconmends that, during the design, procurement, construc-tion, and startup, timely and appropriate interdisciplinary system analyses be pe~formed to assure canplete functional compatibility across each interface for the entire spectrum of anticipated operations and postulated design basis accident conditions.
ttie coordination of interdependent instrumentation and controls in the nuclear island and in the balance of plant will require attention at the time when SWFSSAR-Pl is used as a portion of a nuclear power plant license application.
'Jhese matters should be included in the NRC Staff's standard review plans.
'Jhe proposed orientation of the turbine-generator with respect to the nuclear island is suitable for a single unit installation. For multiple unit power plants, the location and orientation of the units should be such as to yield acceptably 16w probabilities of damage by low-trajectory turbine-generator missiles, or suitable missile shielding should be provided.
'Jhe SWESSAR-Pl and the CESSAR-80 NSSS designs, as do many others, utilize the concept of two-track continuous duty systems which perform critical service functions. In sane cases the probability of failure of one of these systems is not low. The failure of the second system to start or run may cause progressively damaging consequences. The Comnittee reconmends that failures of this kind be evaluated to determine if the necessary reliability exists for these systems and whether remedial measures are appropriate.
Although SWE~Pl and CESSAR-80 include provisions for protection against industrial sabotage, the Ccmnittee believes that further steps can be taken beyond those provided. Prior to the use of SWESSAR-Pl/CESSAR-80 as a portion of an application for a nuclear power plant license, the Utility-Applicant should be required to deoonstrate that acceptable industrial sabotage pro-visions will be incorporated into the plant design.
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Honorable Marcus June 11, 1976
'!he SWESSAR-Pl design includes sane provisions which anticipate the main-tenance, inspection, anq operational needs of the plant throughout its service life, including cleaning and decontamination of the primary coolant system, and eventual decannissioning. However, when SWESSAR-Pl is used as a portion of a nuclear power plant license application the Comnittee believes that the NRC Staff and the Applicant should further review methods and procedures for remving accumulated radioactive contamination whereby maintenance and inspection programs and ultimate deccmnissioning can be nDre effectively and safely carried out.
Generic problems related to large water reactors are discussed in the ccmnit-tee's report dated April 16, 1976. '!hose problems relevant to StiESSAR-Pl and CF.SSAR-80 should be dealt with appropriately by the NRC Staff and the AW].icant as solutions are found.
'!he MYisory Ccmnittee on Reactor Safeguards believes that the items men-tioned above can be resolved during the standardized plant licensing process and that, if due consideration is given to the foregoing and to the recorrmen-dations in the Cannittee's report of September 17, 1975 on CF.SSAR-80, Prelim-inary Design Approval for SWESSAR-Pl to be used in conjunction with CESSAR-80 can be granted in accord with the spirit and purposes set forth.in the Conmis-sion's policy statement on standardization of nuclear power plants as described in WASH-1341, *Programnatic Information for the Licensing of Standardized Nuclear Power Plants* and in conformance with the Regulations of Appendix 0 to Part 50 and Section 2.110 of Part 2 of Title 10 of the Code of Federal Begulations.
References Sincerely yours,
{)ai,e_V.~~
Dade w. M:>eller Olairman
- 1. Pressurized Water Reactor Reference NUclear Power Plant Safety Analysis Report (SWESSAR-Pl) and Amendments 1 through 25.
- 2. Stone and 'Webster Engineering Corporation letters:
- a. January 12, 1976 - Responses to outstanding Issues
- b. February 18, 1976 - De~ign I.Dad Rejection capability
- 3. Report to the Advisory Ccmnittee on Reactor safeguards in the Matter of Stone and 'Webster Engineering Corporation Standard safety Analysis Report PWR Reference NUc1ear Power Plant SWF.SSAR-Pl (and its relation-ship to the CESSAR Standard NSSS Design) Docket No. STN 50-495, Published: May 1976, u. s. NUclear Regulatory Conmission, Office of Nuclear Reactor Regulation.
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