ML20044B771
| ML20044B771 | |
| Person / Time | |
|---|---|
| Issue date: | 12/11/1992 |
| From: | Kress T, Lewis H, Wilkins J Advisory Committee on Reactor Safeguards |
| To: | Selin I, The Chairman NRC COMMISSION (OCM) |
| Shared Package | |
| ML20044B769 | List: |
| References | |
| ACRS-GENERAL, NUDOCS 9303040110 | |
| Download: ML20044B771 (2) | |
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NUCLEAR REGULATORY COMMISSION ~ o { E ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON. D. C. 20555 o, k * * * * +,o'g. December 11, 1992 1 i The Honorable Ivan Selin -{ Chairman U.S. Nuclear Regulatory Commission Washington, D.C. 20555 i
Dear Chairman Selin:
I Though you know us as members of the ACRS, this is a personal letter, not approved by the Committee. It reflects only our own i views. j I Over the last 22 months, the ACRS Subcommittee on Computers in i-Nuclear Power Plant Operations has been running a series of l meetings to explore the regulatory and safety implications of the trend toward digital technology in both existing and proposed j nuclear reactors. In this effort it has sampled the views of the i industry, the staff, the vendors, and a number of 'other elements of l the cermunity, both in and outside of the nuclear world. It has i also heard,_less expansively of course, from both regulatory and user groups outside the United States. i
- i While the ACRS has not yet formulated a
focused. set of 1 3 recommendations, the picture has become sufficiently clear to us to permit one early proposal. Given the-uncontested fact that the l potential for harm from a control-system failure, digital or otherwise, is large, we wish to pass this one along independently. Of course, the potential for safety benefit is also large, as l emphasized in the ACRS letter of September 16, 1992, on Digital i Instrumentation and Control System Reliability. l The impression we have received from the subcommittee meetings is l that the NRC lags its counterparts in other countries, and probably i even the industry. it regulates, in the depth with 'which it addresses. both the risks and. benefits generated by computer-systems. The ACRS letter on the proposed requirement to back up [ digital systems with analog systems addressed one small symptom of the problem; there are many others. It is of course impossible to l deal with a general problem piecemeal, just as one can't turn i ~ country music into Bach one note at a. time. We think the NRC needs a program plan-to provide a stronger sense of direction, aimed at- --- i realistic but clear objectives. In particular we know that-there Dl 1s a large, accessible, and competent community of people concerned '1 l with and expert in these matters-the problems pervade industry and business-and the staff has had only limited contact with them. I f fi 9303040110 921211 PDR CDMMS NRCC CDRRESPONDENCE PDR
The Honorable Ivan Selin 2 December 11, 1992 We know no magic solution to the problem of inadequate resources, but think it would be helpful if the staff (and the Commission) were exposed in some depth to the current thinking of the computer reliability experts, who have for years been hard at work for the aerospace community,.he telephone company, the bankers and money-handlers, the Defense Department, etc. The problems are in each case unique to the co r anity involved, but with features common to all. We recommend that you consider funding a short workshop on the relationship between digital systems reliability and nuclear safety by the National Academies of Sciences and Engineering, which are able to direct the attention of the best technical experts available toward the. specific problems of an agency, at an acceptable cost, while preserving both the appearance and the substance of independence. We do not recommend a full study by the Academies-such efforts can proceed with glacial speed-but the kind of two-or threc.-day workshop, followed by a report, that has worked well on other problems. One would not be looking here for a detailed charter for the future, but rather for an orientation, focus, and state-of-the-art document, from which real planning can proceed. The Academies are uniquely suited to play such a role, with no problem of conflict of interest. We have eschewed the temptation to provide in this letter a proposed set of Terms of Reference for such a workshop, but are convinced that' a reasonable set can be formulated. It would be best if these terms not reflect only the NRC's own perception of I its needs; breadth of perspective is essential to a fresh view. Each of us would of course be happy to assist in drawing up an acceptably focused suite of objectives and deliverables, which should be done in the usual way, through negotiation with the Academies. Sinc ly, \\ / Harold W. Lewis ACRS Member ~ Thomas S. Kress ACRS Member ' f &[ Ernesk Wilkins f,, J. ACns Member ,}}