ML25196A144
| ML25196A144 | |
| Person / Time | |
|---|---|
| Issue date: | 11/08/1978 |
| From: | Lawroski S Advisory Committee on Reactor Safeguards |
| To: | Hendrie J NRC/Chairman |
| References | |
| Download: ML25196A144 (1) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON, D. C. 20555 November 8, 1978 Honorable Joseph M. Hendrie Chairman U. s. Nuclear Regulatory Canmission Washington, DC 20555
SUBJECT:
REPORI' CN '!HE FAST FLUX TEST FACILI'IY
Dear Dr. Hendrie:
During its 223rd meeting, November 2-4, 1978, the Advisory Canmittee on Reactor Safeguards completed its review of the proposed operation of the Department of Energy's (DOE) Fast Flux Test Facility (FF'l'F).
The ACRS reported previously on the construction phase of this project on July 13, 1971, January 13, 1972, May 18, 1973, and July 15, 1975. The project was also considered during the 221st meeting, September 7-9, 1978 and at Subcom-mittee meetings held in Washington, DC on July 12, 1978 and August 10, 1978.
During its review, the Canmittee had the benefit of discussions with repre-sentatives of the Reactor Researdl Technology Division of the DOE (Project),
their contractors and consultants, and the NRC Staff. The Canmittee also had the benefit of the documents listed below.
The FFTF is a 400 MWt sodium cooled fast reactor located at DOE's Hanford Reservation in Benton County, Washington.
The site is about 4 1/2 miles from the Colurrbia River, the nearest boundary of the reservation, and about 10 miles north of Richland, Washington.
In view of the fact that this reactor is unique, appropriate detailed procedures and standards of the kind used in the review of light water re-actors were not available for the review of FFI'F.
Because the FF'l'F is a DOE facility the scope of the NRC review was defined by the DOE request that NRC provide advice regarding the adequacy of the FFTF design and technical specifications to ensure safe q>eration. The NRC review did not include construction audits, assessnents of the *as built" configuration, or evalu-ation of acceptance test results that would verify that the plant was con-structed in accordance with the design criteria and documentation. Provi-sions for safeguards and security were also excluded fran review.
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Honorable Joseph M. Hendrie 2 -
November 8, 1978 The NRC Staff agrees with the Project that failure of the reactor inlet piping need not be oonsidered as a cause of a core disruptive accident (CDA) provided that certain oonditions are met. These include preservice and inservice inspection of piping, leak detection instrumentation, and an appropriate materials surveillance program. The Project has carmitted to developing an ultrasonic testing (tJT) device for high temperature use, to inservice inspection of selected, high stress welds on the secondary sodium loops when the UT device is available, and to installation of so-dium aerosol leak detection systems in the heat transport cells. A mate-rials surveillance program will be conducted using test subassemblies, as well as in-reactor and hot leg components that are removed.
In addition, the NRC recommends that a oold preservice inspection be conducted on the hot crossover piping welds and that inservice inspections be implemented as soon as practicable. The Camnittee supports these recamnendations.
The Project has performed studies of various postulated core disruptive accidents (CDA).
'lhe NRC Staff has concluded that the calculated prarpt energetics fran CDAs are within the capability of the contairment system.
The ACRS ooncurs with the Staff conclusion.
The FFTF does not have a Class lE power supply to provide decay heat re-moval.
Instead, the Project will depend upon natural convection oooling in the event of loss of offsite i;x:,wer and failure of the oosite diesel generators. 'lhe Project's calculations indicate that natural circulation will provide decay heat removal. It is proposed that the natural circula-tion decay heat removal be measured during the startup testing. '1he ACRS ooncurs that the adequacy of the decay heat removal by natural circulation should be experimentally verified.
The NRC Staff and the Project have not yet agreed on the adequacy or: con-tainment for dealing with the oonseguences of sane low probability acci-dents which lead to the potential for generation and release to containnent of significant quantities of sodium aerosols, hydrogen and other wlatile gases. In its report of July 15, 1975, the ACRS recamneooed that consider-ation be given to the possible usefulness of sand-and-gravel filters for the removal of airborne particulates. During the current review, the NRC Staff has recoomended that measures be taken by the Project to permit the measure-ment and control of the hydrogen ooncentration in the containnent, to further reduce the chance of a damaging explosion. The NRC Staff has also recamnended that means be included for oontrolled venting. 'lhe ACRS supports these Staff positions and recanmends development of additional mitigation measures, such 520
Honorable Joseph November 8, 1978 as a sand and gravel filter, for possible addition to the controlled venting system to provide still further assurance of limited radioactivity releases in the event that one of these low probability accidents should occur.
As pointed out in a previous report, the ACRS has recognized that the FFl'F is a special test facility located on a favorable site. Both positive and negative aspects of this situation have been considered throughout the re-view.
The ACRS believes that if due regard is given to the matters mentioned above, and in previous reports, it is acceptable for startup and operation of the FFl'F to proceed.
References:
Sincerely,
!::t,h,,-~'-',:
- n Lawroski Chairman
- 1. U.S. Energy Research and Developnent Administration (now OOE), "Final Safety Analysis Report, Fast Flux Test Facility," Vols. 1-10, dated Decerrber 1975 with Amendments 1-27 and Supplements 1-28.
- 2. U.S. Nuclear Regulatory Camnission, "Safety Evaluation Report, USOOE, Fast Flux Test Faciltiy," USNRC Report, NUREX;-0358, dated August 1, 1978.
- 3. Letter fran R. L. Ferguson, ERDA, to R. P. Denise, NRC,
Subject:
NRC Review and Advice on the FFl'F, dated November 13, 1975.
- 4. Letter fran R. L. Ferguson, ERDA, to R. P. Denise, NRC,
Subject:
Scope of NRC Review of FFl'F FSAR, dated August 20, 1976.
- 5. Letter fran R. L. Ferguson, ERDA, to R. P. Denise, NRC,
Subject:
FFTF Safeguards and Security, dated July 14, 1977.
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