ML19347B776
| ML19347B776 | |
| Person / Time | |
|---|---|
| Issue date: | 08/15/1980 |
| From: | Catton I Advisory Committee on Reactor Safeguards |
| To: | Duraiswamy S Advisory Committee on Reactor Safeguards |
| References | |
| RTR-REGGD-01.097, RTR-REGGD-1.097 ACRS-CT-1278, NUDOCS 8010150642 | |
| Download: ML19347B776 (2) | |
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e7./.1yy MEMORANDUM 15 August 1980
.. ;.'.": T_5 p:,1 1 5 i TO:
S. Duraiswamy J
' 150Ei CCMM'Ti'E ON
. ;.c s st.FEG.t. cts FROM:
I.. Ca tton g
SUBJ:
Regulatory Guide 1.97 Regulatory Guide 1.97 provides a fairly complete list of instrumentation along with required instrument range and design category. The accuracy required for the various instruments needs to be more completely specified to complete their specification. The staff is to be commended for their effort.. It is possible that further instrumentation needs may arise as a result of further studies like that given in NUREG/CR-1440. The amount of additional instrumentation will, however, probably be minimal and could be added via revision at a future data. Unfortunately, the regulatory guide does not appear to be in concert with industry and NRC efforts in defining instrumentation requirements for a number of different emergency response functions and for satisfaction of the Tade Action plan.
Regulatory Guide 1.97 in its present form attempts to satisfy a number of different needs without clearly indicating what measurement satisfies what need(s). Previous editions of the regulatory guide were more restricted and a well thought out integration of the various needs has not been demonstrated in the current version. A section in the regulatory guide or appendix to the regulatory guide, should be prepared that shows how the instrument needs of the Safety Parameter Display System (SPDS),
the Emergency Operations Facility (EOF), the Technical Support Center (TSC),
the Nuclear Data Link (NDL), and other emergency response facilities are to be integrated into a logical and consistent paskage. A table showing how the various instruments satisfy the needs of SPDS, E0F, TSC and NDL as well as other emergency facilities could be very helpful. The reader should be given sufficient information to direct him to reports, and other documentation covering the various facets of the total package as well as dates they must be implemented.
Another area where overlapping requirements exist is the TMI Action Plan.
The follo4ing items appearing in the Task Action Plan bear on the Regulatory Guide to some degree:
- 1. D.1 Control room design reviews I.D.2 Control room design - Plant Safety I.D 3 Control room design - Safety System Status Monitoring I.D.4 Control room design - Control Room Design Standard I.D.5 Control room design - Improved Control Room Instrumentation 8910150 N L 1
1 8/15/80 TO: Duraiswamy FROM: Catton Page 2 II.B.3 Consideration of Degraded or Melted Cores in Safety Review -
Post Accident Sampling II. F.1 Additional Accident Monitoring Instrumentation Leading to Inadequate Core Cooling II.F.2 Identification of and Recovery From Conditions II.F.3 Instrumentation for Monitoring Accidents (R.G.l.97)
II.F.4 Study of Control and Protective Action Design Requirements II.F.5 Classification of Instrumentation, Control and Electrical Equipment III.A.2 Improve Operations Center III.A.3 Improving NRC emergency preparedness III.A.4 Nuclear Data Link III.D.3.3 Inplant Radiation Monitoring 1
III.K.3 Table C.3 Item 6 Instrumentation to verify natural circulation Item 23 Central water level recording Compliance with Regulatory Guide 1.97 will to some extent satisfy some aspect of the items in the list. Further, satisfying the Task Action Plan may satisfy the Regulatory Guide in its entirety. Some discussion of the Tade Action Plan and Regulatory Guide 1.97 should appear in the guide. A table listing the instrumentation and, wnat aspect of the Task Action Plan is sa'.isfied would help in decreasing the confusion.
The need for PWR level. sensing and BWR core outlet temperatures still seems to be arguable. In a PWR, the utility of core exit temperatures was clearly demonstrated following the TMI-2 incident. Before one can conclude that BWR core exit temperatures would serve no useful purpose, one needs to assess whether or not the post-severe core damage accident period would be similar to that experienced at TMI-2.
It is my initial view that it would not be. The counterpart to the natural circulation mode at TMI-2 would be boiling in the damaged core and condensation in the condensers. Hence one probably doesn't need core exit thermocouples, even though they have some utility during the period of severe core damage. Level sensing in a PWR is another matter. If it is to operate like a boiler, then it must have boiler type instrumentation, namely level sensing. The need for PWR core exit temperatures was demonstrated at TMI-2.
As a final comment, human factors cannot be ignored. The industry view is to reduce the number of variables. The answer is really one of data processing and making information available properly. The A, B, C, 0 and E categories spelled out in the Reg. Guide appear to do this. Some description of how the interfacing with human factors considerations will be made is needed for completeness. Reference to another Reg. Guide i
Leaving it open for speculation leads only to may be the answer.
confusion. Until such a Reg. Guide exists (if it does not already),
the instruments required by the Reg. Guide can be wired into existing panels as many will be just an upgrade of existing instruments.
Implementation of instruments to follow the accident that are capable of surviving hostile environments is long overdue.
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