ML19207A591
| ML19207A591 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/06/1979 |
| From: | Mattson R Office of Nuclear Reactor Regulation |
| To: | Saxe R North Carolina State University, RALEIGH, NC |
| Shared Package | |
| ML19207A592 | List: |
| References | |
| NUDOCS 7908210171 | |
| Download: ML19207A591 (9) | |
Text
f Distri bution:
Central Files V. Stello RIreland NRR:R/F SECY 79-1431 R. Boyd RSatterfield KSinger, ED0-6287 HDenton R. DeYoung LBeltracchi RFrazier, EDO-6287 ECase D. Bunch GErtter, ED0-5207 DSS:R/F RJMattson R. Tedesco f1Groff, ED0-6287 DSS:ICSB:R/F RMinogue D. Ross FSchroder JDavis Stevine K. Cornell PDR R/F JUN 6 1979
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Professor R. F. Saxe School of Engineering North Carolina State University 2
Box 5636 Raleigh, North Carolina 27650
Dear Professor Saxe:
Your letters of April 20 and !?ay 9,1979 to Chaiman Handrie have been referred to me for reply. Please excuse the delay in responding to your letters. The staff has been extremely busy with many Three Mile Island Unit 2 follow-up ac-tions.
It is becoming apparent that the ideas you have proposed have merit and are under active study by the !!RC technical staff.
Your lecter of April 20, 1979 discusses the use of digital computers as advisory, memory aid devices to better assist the plant operator in making decisions. You note that digital computers, if properly implemented, are better suited to repetit ive, and correct execution of long-tern routine operation: such as monitoring the status of systems and components than a human operator. We agree that more shoul" be done in this area and have intensified our assessment of man-machine interface problems subsequent to the Three Mile Island accident.
The staff's initial assessment of the Three Mile Island accident is presented in HUREG-0560, " Staff Report on the Generic Assessment of Feedwater Transients in Pressurized Uater Reactors Designed by the 3abcock a '!11cox Company," May 1979 (copy enclosed). One 'of the recommendations made was that:
"A study should be undertaken by MRC of actions that could make the operator a more effective recovery a';ent or incident / accident mitigator. Such actions wuld extend the defense-in-depth concept through the use of on-line diagnostic conputer sys' ems to seek ways to prevent (inhibit) inappropriate actions and pronote productive intervention."
The recommended study has been initiated and is concentrating upon monitoring and disturbance analysis syster.ts.
'tegulatory Guide 1.47, "0ypassed and Inoperable Status Indication for '!uclur Po.c Plant Safety Systems" addresses monitoring systens. A recent computer '.ased dasi 7908210l1,
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.. in response to Regulatory Guide 1.47 is the TVA Status Monitoring System (SMS).
This system is designed to automatically alert the control room operator in the event that a fluclear Power Station Safety system, or any integral element of that. system is bypassed or has been rendered inoperative by misalignment of equipment or by loss of power as a consequence of removal of fuses or opening of circuit breakers.
I Pioneering development of digital computer based disturbance analysis systems has been conducted at the OECD Halden Reactor Project, Halden, Norway, and such a system will be used on a nuclear plant in West Gemany. A description of this system is contained in EPRI NP-640, " Assessment of Technologies Essential to the Application of Advanced Systems for Process Control" January 1978. Under our Technical Assistance Program with Oak Ridge flational Laboratory, we currently have a consultant who is evaluating this system for the staff.
As stated in your letter of April 20, the unforgetting, logical capabilities of the digital computer can serve a significant role in nuclear safety; however, if the computer is not properly implemented,it can very well be a detriment to safety:
e.g., if the operators place too.much reliance on its capabilities. This is one of the reasons the Nuclear Regulatory Commission exrended significant resources in the evaluation of the first operational digital computer based safety system recent licensed at Arkansas fluclear One, Unit 2.
For your information, our review standar:
and evaluation of this system may be found in f:UREG-0308, " Safety Evaluation Report-Arkansas Nuclear One, Unit 2" Docket ?!o. 50-353, November 1977, and the supplements to this report.
The l:uclcar Regulatory Commission has formed i essons Learned Task Force to asser -
the need for changes in regulatory requirement in light of the Three Mile Is' 4 accident. One of the expected actions will be to provide further impetus and go ance to the studies related to application of digital computers as operational w a.
sincerely appreciate your suggestions and hope the foregoing provides you with surance of a shared concern.
Sincerely, s'I
/
Roger J. "attson, Director Division of Systems Safety Office of 'luclear Reactor Regulation
Enclosure:
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.. in response to Regulatory Guide 1.47 is the TVA Status Monitoring System (SMS).
This system is designed to automatically alert the control room operator in the event that a Nuclear Power Station Safety system, or any integral element of that system, is bypassed or has been rendered inoperative by misalignment of equipment or by loss of power as a consequence of removal of fuses or opening of circuit breakers.
Pioneering development of digital computer based disturbance analysis systems has been conducted at the OECD Halden Reactor Project, Halden, Norway, and such a system will be used on a nuclear plant in West Germany. A description of this system is contained in EPRI NP-640, " Assessment of Technologies Essential to the Application of Advanced Systems for Process Control" January 1978. Under our Technical Assistance Program with Oak Ridge National Laboratory, we currently have a consultant who is evaluating this system for the staff.
As stated in your letter of April 20, the unforgetting, logical capabilities of the digital computer can serve a significant role in nuclear safety; however, if the computer is not properly implemented,it can very well be a detriment to safety; e.g., if the operators place too much reliance on its capabilities. This is one of the reasons the Nuclear Regulatory Commission expended significant resources in the evaluation of the first operational digital computer based safety system recently licensed at Arkansas Nuclear One, Unit 2.
For your infomation, our review standards and evaluation of this system may be found in NUREG-0308, " Safety Evaluation Report, Arkansas Nuclear One, Unit 2" Docket No. 50-368, November 1977, and the supplements to this report.
The Nuclear Regulatory Commission has formed a Lessons Learned Task Force to assess the need for changes in regulatory requirements in light of the Three Mile Island accident. One of the expected actions will be to provide further impetus and guid-ance to the studies related to application of digital computers as operational aids.
We sincerely appreciate your *"ogestions and hope the foregoing provides you with assurcace of a shared conc Sincerely, t
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Box 5636
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Dear Professor Saxe:
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"'ar y0u for %ur letters of April 20 and ? y 9 and. olease-accept-our-apologtes La w reL< w d A.ma..tu.,upQ./ 8,.ad ma y-w /'m.g J s us.
fe cu S : taedy -responm-J ws..mt.ul w,d su,w.dev a<Zeh.4Lf Ju ?/L. w.cc /L. ', co, f < bit, a
IS S Your letter of April 20,suggert: nd discusses the use of digital computers as JG ns.
u-advisory, aide-memorie devices to,sassist the plant operator, You Amt+er-Stity that ee digital computers, if properly implemented, are better suited to t3h repeauve, and correct execution of long-term routine operatioas such as L o%L-monitoring systems and components fc
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%b operator. We "c'"ed tr agree that more should be done in @e area and w& loc.u have intensified our assessment of ee man-machine probTems subsequent to the A
Three Mile Island accident.
ne ""cl aa r Dagul:tery Comiss. ion hae formed Messons--L-ncd 'fa.k Force t -
.c & S mierte the-Thr:c,"ile-Island ecciucn t.
The Cc-W rm ' e initiai assessment n
,.wuchis..A 44 of the, accident weee presented in NUREG 0560, " Staff Report on the Generic Assessment of Feedwater Transients in Pressurized Water F.eactors Designed by Ws w Q T A. A u.-an.su.. d i %.a the Babcock & Wilcox Company," May 1979 Our e c enda-icn: " t": ex sti,c c
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"A study should be undertaken by NRC of actions that could make the operator a more effective recovery agent or incident / accident mitigator. Sch actions would extend the defense-in-depth concept through the use of on-line diagnostic computer systems to seek ways to present (inhibit) inappropriate actions and promote productive intervention."
$/w summusNM y Cm. study has been initiated and we-a.ee concentrating om.- - f f;. t3 upon tmr type
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f turbance Analysis Systems.
.c7; Regulatory Guide 1,47, " Bypassed and Inoperable Status Indication for Nuclear Power Plant Safety Systems" addresses monitoring systems. A recent comruter as b sed design in response to Regul Guide 1.47 is the TVA Status Monitoring System (SMS). This system is,to' automatically alert the control room operator in the event that a Nuclear Power Station Safety system, or any integral element of that system, is bypassed or has been rendered inoperative by misalignment of equipment or by loss of power as a consequence ofyremoval of fuses or opening of circuit breakers..
lc J9lt ioneer development of digital computer based Disturbance Analysis Systems has been conducted at the OECD Halden Reactor Project, Halden, Norway _ A description of this system is contained M EPRI NP-640, " Assessment of ca a
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-f-Technologies Essential to the Application of Advanced Systems for Proces Control" January 1978, Under our Technical Assistance Program with Dak Ridge National Laboratory, we currently have a consultant who is evaluating this system for the staff.
As stated in your letter of April 20, the unforgetting, logical capabilities of the digital computer can serve a significant role in nuclear safety.
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,.However, if the computer is not properly implemented, it can very well be
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a detriment to safety. This is one of the reasons wh[ the Nuclear Regulatory Commission expended significant resources in the evaluation of the first op-iC~'
digital computer based safety system recently licensed at Arkansas Nuclear One, Unit 2 For your information, our review standards and evaluation
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Sincerely, PCUR :PJG8UL
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TO: O comm.ss.oner O cen. counsei XM E ec. oir./oper.
O soiictor O con,. ti son O secret.rv O eudi.c Avfairs O
Incoming: _.'L F. Saxe. Prof.
Noc'h Carolina State Univ.
From:
ro:_Cb irman Hendrie
_ o,e_S/9/79 ecuests reolv to 4/20/79 ltr. re:
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