ML19322C212
| ML19322C212 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/04/1976 |
| From: | Beckerley J NRC OFFICE OF POLICY EVALUATIONS (OPE) |
| To: | Huberman B NRC COMMISSION (OCM) |
| Shared Package | |
| ML19322C211 | List: |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001160623 | |
| Download: ML19322C212 (3) | |
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ENCLOSURE 4
UNITED STAf ts
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- eee' 9 June 4, 1976 MEMORANDCl FOR: Ben llubernan 'R FROM:
Jim Beckerley / I
SUBJECT:
1.ICllTNING PROTECTION: TECllNICAL CONSIDERATIONS A1, Ted and I i ave discussed the subject and the following represents a consensus on the technical aspects.
The possible effect of lightning on nuclear power reactor safety should be considered in the NRC safety evaluation.
General Design Cri-terion 2 of 10 crn Part 50, Appendix A, requires the power plant designer to consider the effects of " natural phenomena" on " structures, systems, and components important to safety." Although lightning is not listed in Criterion 2 following the "such as", it is considered to be a natural In Regulatory Guide 1.70, Section 2.3.1.1 (" Regional phenomenon.
C13natology"), the applicant is requested to furnish "scasonal and an-nual f requencies of severe weather phenocena, including... thunderstorms, lightning..." at the site. This explicit reference shows that lightning has been considered by the site safety stafi o be a potentially signifi-cant naturni phenomenon.
From a preliminary scanning of' Standard Review Plans (SRP), we can find no specific reference to review of lightning hazards to nuclear power plants.
Chapter 8 (" Electric Power") of the Standard Review Plan notes in the introduction (by reference to Tabic 8-1) that Cencral Design Cri-terion 2 (CDC 2) is " currently applied by the staff to safety -related cicctric power systems." However, in SRP 8.2 ("Offsite Power System")
where CDC 2 is specifically considered (Sec. III, item 6), Ifghtning or thun!ctstores are not mentioned. This is somewhat anonalous since Reg-ulatory Guide 1.70, Sec. 8.2.1, specifIcally asks the applicant to coa-sider the effects of " Unusual features...c.g.,... hich thunderstorm ratc" en tranr.cfssion linen supplying peuer for safetv loads.
In SRP 8.3.1 ("A-C Power Systems (Onsite)"), Gr. cal Design criterion 2 is nutsd only in connection with seisnic conside. Lions (Sec. III, item 2c).
ThelgercralapplfcabilityofTable8-11.t noted, however.
The same com-ments hold for SRP 8.3.2 ("D-C Power Systems (Onsite)").
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Chap'tcr 7 (" Instrumentation and Controls") of the Standard Review Plan ingludes a Tabic 7-1 that is referred to in SRP 7.1 as listing "the crt-teria currently applicable to safety-related instrumentation and control
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I systems." The tabic includes General Design Criterion 2 and indicates its applicability to all Chapter 7 review plans.
Each SRP of Chapter 7 refers to Table 7-1 but does not include any specific references to CDC 2, although there are references to scismic qualification.
In SRP 7.3 (" Engineered Safety Feature Systenu"), the reviewer is r'eferred to many of the SAR chapters but not the chapter (i.e., Chapter 2) which is relevant to CDC 2.
In Appendi:: 7-B ("rencral Ay,enda, Stat ion Site Visits"), there are several references to " potentia] for dar.cac due fire, flooding, missiles, etc."; it is not apparent that the "etc." includes lightiiing.
Throughout the Standard Rcview Plan and in Regulatory Guide 3.70, there are references to the need to satisfy the requirements of IEEE Std. 279-1971 (ANSI N42.7-1972), " Criteria for Protection Systems for Nuc1 car Power Cencrating Stations." We do not hr.ve a copy at hand to chcck whether lightning protection is covered by the IEEE-279 criteria, llow-cver, it is quite possible that, in this or some other standard cited in the SRp, there may be a lightning protection criterion.
Certainly, the need for lightning protection is well known.
In Chapter 10. "In-j stallation of Instrumentation Systems", of " Nuclear Power Reactor Instru-r mentation Systens llandbook, Vol.1 (USAEC,1973)", the subject is discussed in connection with grounding design.
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i As far as information on lightning is concerned, it is not true that "littic information" is availabic in the open literature. Although certain USAF work (e.g., at the Air Force Cambridge Research Center) is classified, much of it has been published, particularly information of general value to the cicctric pouer industry.
I have anong my older books, one which reports on a USAF Conference (" Thunderstorm Elcetricity", ll.R. Byers, Ed.,
Univ. Chicago Press, 1950, 344 pages).
This has an excellent brief sumnary of power-line protection information as known at that time.
Other chapters in the book describe results of many research efforts ry nsored by USAF aad the electric power industry.
i In summary, we.belicyc NRC regulations require consideration of lightning g
protection of structures, systems, and cenponents inportant to safety.
Because applicants are required to provide information on thunderstorms I
and lightnin,; at the site, it appeart, to us that applicants are also re-g quired to consider the potenti:1 effects of lightning on plant safety.
TheStlandardRevicuPlanimplics,butdoesnotexplicitlystate, that the
- NRC st!af f review of the cpplica." 's proponed plant design includes an esal-uatio:I of the' plant's safety in withstanding the effects of lightning.
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Ben Huberman l We can not determine, from the Standard lleview Plan, uhether the staf f does, in fact, consider lightning hazards in reviewing proposed nuclear power plants.
For this reason, the staff should consider whether the Standard Iteview Plan and the Standard i':,l.a fort.:at (1:e:;ulator;. L'uide 1.70) should be revised to c:<plicit2: requir. consider..tlon of the patentfal effcets of lir,htstn; on nuelt-r power p1hnt safety, i.e.,
to explicitly include lightning as a natural phenorcan covered by General Design Cri-terion 2 of 10 Cra Part 50, AOpendix A.
If the etaff decides s.uch revi-sions are unnecessary, ' hen the deciroir,a and the supporting reasons should t
be documented.
cc: Al Jennche Ted Quay f
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