ML20140F507

Submits Questions on SECY-92-215 That De Planque Requested Staff Response to When Final Rule Package Forwarded for Commission Approval

ML20140F507
Person / Time
Issue date:	08/18/1992
From:	Chilk S NRC OFFICE OF THE SECRETARY (SECY)
To:	Taylor J NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
Shared Package
ML20007G200	List: ML20140E433 ML20140E885 ML20140E897 ML20140E903 ML20140F445 ML20140F466 ML20140F507 ML20140F517 ML20140F530 ML20140F535 ML20140F540 ML20140F555 ML20140F561 ML20140F568 ML20140F575 ML20140G488 ML20141C175
References
FRN-57FR47802, RULE-PR-100, RULE-PR-50, RULE-PR-52 AD93-1-024, AD93-1-24, SECY-92-215-C, NUDOCS 9705050030
Download: ML20140F507 (2)

Text

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UNITED STATES CyS: Taylor p a .

• NUCLEAR REGULATORY COMMISSION l

l, f* j WASHINGTON, D.C 20$55 Sniezek Thompson Blaha k*****p# LSoffer, RES OFFICE OF THE Murley, NRR SECRETARY August 18, 1992 g g3_g t' P 8-MEMORANDUM FOR: James M. Taylor Executive Director for ations FROM: Samuel J. Chilk, Secre .

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SUBJECT:

QUESTIONS ON SECY-92-2}5 Commissioner de Planque requested staff response to the following questions when the final rule package is forwarded for Commission approval:

1. With respect to the five year update on manmade hazard's,.

what has been the experience from cases such as San onofre where such updates were required, or from any other

! instances? Discuss the number and significance of concerns l and the implementation with respect to the value of a five l

year (or some other frequency) update.

l

2. Further detail is needed on hov staff would propose to consider both the deterministic and probabilistic seismic hazards with " comparable weight", particularly if the

! controlling earthquakes from the two approaches are dissimilar.

3. Staff should provide a more detailed discussion of the relationship of the early site renewal process and the proposed changes to Part 100. For instance, what is the purpose of the proposed change to Appendix Q to Part 527 If possible, provide a "timeline" example of how the 40 year projection of population distribution would apply for a case of an early site permit review unde.r Subpart A of Part 52, a renewal of such a permit, a review under Appendix Q or a COL review under Part 52 where no early site review was done.

4. Based on the sample comparison of present population density with the projections that were made at the time of l licensing, give an estimate of the error of those projections and the implications for the proposed population density criteria.

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I l 5. What has been done with respect to population distribution

in environmental reviews associated with "CP/OL" recapture?

l What does staff intend to do for license renewal?

4600) (RES) (SECY Suspense: 6/1/93) 9000200 i

I l cc: The chairman  !

l Commissioner Rogers l Commissioner Curtiss l Commissioner Remick Commissioner de Planque OGC OCAA OIG L l

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%, # Blaha Scroggins, OC OFFCE OF THE dordan, AEOD SECRETARY August 18, 1992 AMurphy, RES LSoffer, RES i DMeyer, ADM  !

BShelton, IRM TMurley, NRR MEMORANDUM FOR: James M. Taylor Executive Director for Op tions 1 FROM: Samuel J. Chilk, Secretar J

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SUBJEC'"?. SECY-92-215 - REVISION Ol'10 CFR PART 100, j REVISIONS TO 10 CFR PART {0\ NEW APPENDIX B '

TO 10 CFR PART 100 AND NEW APPENDIX S TO 10 l CFR PART 50 l

l

The Commission (with all Commissioners agreeing) has approved the issuance of the proposed documents with the changes discussed below and.in the attached pages for a 120-day public comment period. Additionally, the Commission certifies.that this rule will not have a significant economic effect on a substantial number of small entities pursuant to-the Regulatory Flexibility Act of 1980 (5 U.S.C. 605 The Commission also notes the I items conta*ned in paragrap(b)). h 3. of the staff's recommendations.

The Federal Reaister notice should solicit comments on the pros t and cons of grandfathering existing sites with an exclusion area less than 0.4 mile for the possible placement of additional units, if found suitable from safety considerations.

-(EDob (RES) (SECY Suspense: 9/20/92) 9000200 The Federal Reaister notice should be modified such that the intent of proposed revisions that impose new requirements are clearly stated in the rule and the associated regulatory guide c:ntains surrogatos for their implementation.

-(EDot- (RES) (SECY Suspense: 9/20/92) 9000200 The proposed regulatory guides and SRP should be modified to ensure that figures and tables in the regulatory guides clearly define the units used (e.g., annual probabilities) and that a list of references be included, where appropriate.

-(Eco.h (RES) (SECY Suspense: 9/20/92) 9000200

j. SECY NOTE: THIS SRM, SECY-92-215, AND THE VOTE SHEETS OF ALL COMMISSIONERS WILL BE MADE PUBLICLY AVAIIABLE 10 l WORKING DAYS FROM THE DATE OF THIS SRM cpy gygryg-

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Staff shoald also seek international comments on the 0.4 mile c clucien area and population densities in order to obtain a broader range of insights on this matter.

l 4600)- (RES) (SECY Suspense: 6/1/93) 9000200 The upcoming advanced notice e,f rulemaking on 10 CFR Part 50 which deals with decoupling the site from the source term should .!

include a request for public comment on reconsideration of  !

current requirements on Energency Planning Zones. 1 4500) (RES) (SECY Suspense: 9/20/92) 9000201 l

Attachments: 1 As stated l

l l cc: The Chairman Commissioner Rogers Commissioner Curtiss 1 Comriesioner Remick  !

Commissioner de Planque l OGC l OCAA l

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, go iu $eems 4o be c. denid e@ PRVl 8ib-2o keen bhwitonmut,

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be used for judgint the acceptability of future nuclear power plant sites.  !

! Similarly, in keepir g with Regulatory Guide 4.7, the projected population density i ' 40 years after initial site approval dould not exceed 1000 people per square mile.

With regard to the petition by Free Environment, Inc. (PRM-50-20), the

{ Commission concludes that the criteria in Regulatory Guide 4.7 provide a reasonable degree of . separation for a range of population centers, including

" major" population centers, depending upon their size. Further, codifying the

! s population density criteria of this guide is expected to ensure a low level of i

risk, including the risk of latent cancer fatality as well as long-term land contamination. Finally, the Comission concludes that granting of the petitioner's request to specify population criteria out to 40 miles rather than

! 30 miles would not substantially reduce the ri.is to the public, but could j significantly increase the difficulty of obtaining suitable reactor sites in some

{ regions of the nation. Forthesereasons,theCommissionhasdecidednotto])

adopt the proposal by Free Environment, Incorporated. _

! ' An important point regarding population projections and their application should be made. Because the validity and reliability of population projections, particularly for relatively small regions, decreases markedly as the projection i time period increases, population projections for the purpose of assessing site i suitability are to be limited to 40 years. Population projections beyond this i time period become unreliable and speculative. The 40 year period for population j projections is to be distinguished from the 60 year or more plant lifetime.

[ Because analyses have shown that current plant designs can meet the i i

Commission's Safety Goals and that other risks can be kept at a very low level '

at sites that have significantly higher population densities than those being proposed, the Commission wishes to emphasize that these population density levels

, do not indicate the upper limits of acceptability. These levels represent

! preferred values, that, if exceeded, require that an applicant provide j .

justification for not locating a reactor at an alternative site having a lower population dec W Therefore, the population density limits proposed in the regulation r ...d to be used only in the siting decision process to be applied at *iw -f initial site approval or early site permit renewal to

! determine wL e . Urnative sites that have lower population densities should i be considered < t,ommission does not intend to consider license conditions or

operating res6rictions upon an operating reactor solely upon the basis that the I

! population density around it may reach or exceed the proposed siting decision i values given above during the plant lifetime. Because of the possibility for I

confusion resulting from numerical values being cited in the regulation, the Commission is also requesting comments on whether numerical population density l values should be cited in the regulation or whether these should be stated in a '

regulatory guide only. The Commission is also requesting comments on whether the values of 500 and 1000 persons per square mile are appropriate, and whether i population density criteria need be specified out to 30 miles, or whether another j' distance is more appropriate.

4

! D. Meteoroloaical Factors. Radiological doses that incorporate site i meteorological data need no longer be calculated for~ the purpose of determining i

' site suitability. Meteorological data will still be needed for safety analysis and for assessing the adequacy of certain plant features, as well as to determine plant adequacy in regard to meteorological extremes, such as tornados and maximum

probable precipitation. Therefore, the proposed regulation maintains the-i requirement to collect and characterize meteorological data representative of the l site. ~

j The Commission has examined the variations in site meteorology that have i FRN - 9 i

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!' 100 has adopted an approach using both probabilistic and deterministic

evaluations. The staff proposes to use both the deterministic -

! being used) and the probabilistic evaluations together and compa(currently re the results j of each to provide insights unavailable if either method were used alone. The principal limitations of the deterministic evaluation --- its ability to j

incorporate only one model and one data set at a time and its inability to l j allow weighted incorporation of numerous models --- can be assessed by comparing its results with the results of a probabilistic evaluation  ;

j accomplished in parallel. Similarly, the principal limitation of the l

probabilistic evaluation --- its tendency to allow its results to be dominated '

by the tails rather than the central tendency of distributions of uncertain ,

knowledge or expert opinion --- can be assessed by comparing its results with '

the results of one or more deterministic evaluation $.

j The NRC believes that taken together, this approach can allow more l l j  !

infomed judgments as to what the appropriate Safe Shutdown Earthquake Ground  ;

i Motion should be for a given site. Both the applicant's judgments and those of the NRC will be improved. Therefore, the NRC believes that this approach l is the best way to accomplish the objective of this aspect of the revised j

regylation and arrive, through analysis, at a site-specific ground motion that i

! appropriately captures what is known about the seismic regime. Using both , i probabilistic and deterministic evaluations wfM lead to a more stable and  ;

i predictable licensing process than in the past. Nt> comgkwmt each oHw shoddl l j In order to implement this approach, the NRC has proposed a requirement

that the probability of exceeding the Safe Shutdown Earthquake Ground Motion

!' at a site be lower than the median probability of exceedance computed for the current population of the operating plants. This requirement assures that the design levels at new sites will be comparable to those at many existing sites, particularly more recently licensed sites. This criterion is also used to identify significant seismic sources, in terms of magnitude and distance, j affecting the estimates of ground motions at a site.

4. Safe Shutdown Earthouake. The existing regulation (10 CFR Part 100, Appendix A, Section V(a)(1)(v)) states that when the maximum vibratory

, accelerations of the Safe Shutdown Earthquake at the foundations of the

! nuclear power plant structures are determined to be less than one tenth the acceleration of gravity (0.1 g) ..... it shall be assumed that the maximum j

l j

vibratory accelerations of the Safe Shutdown Earthquake at these foundations i i are at least 0.1 g (Also,Section V(a)(1)(iv) contains the phrase "at each of l the various foundation locations") The location of the seismic input motion control point as stated in the existing regulation has led to confrontations

with many applicants that believe this stipulation is inconsistent with good

!^

engineering fundamentals.

The proosed regulation would move the location of the seismic input 7

] notion control point from the foundation-level to free-field, at the free j

ground surface or hypothetical rock outcrop, as appropriate. The 1975 version.

1 of the Standard Review Plan placed the control motion in the free-field. The i proposed regulation is also consistent with the resolution of Unresolved

! Safety Issue (USI) A- 0 , " Seismic Design Criteria" (August 1989), that i resulted in the revisiot, of Standard Review Plan Sections 2.5.2, 3.7.1, 3.7.2, j and 3.7.3. 4, 4;gmt rpNs of Ac Yea yond surfacef and so 4vnda%n level'siwuld

{ k claciked, as es4t h sdiens VM and V M d atte*A: 8 3 4o et tretened fa,+ too.

1

5. Value of the Ooeratina Basis Earthouake Ground Motion (DBE) and Reautred OBE Analvses. The existing regulation (10 CFR, Appendix A,Section V(a)(2)) states that the maximum vibratory ground motion of the OBE is one-

' FRN - 13 1 --

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2. In making use of the probabilistic and deterministic evaluations as proposed in Draft Regulatory Guide DG-1015, is the proposed procedure in Appendix C to DG-1015 adequate to determine controlling earthquakes from the probabilistic analysis?

3. In determining the controlling earthquakes, should the median values of the seismic hazard analysis, as described in Appendix C to Draft Regulatory Guide DG-1015, be used to.the exclusion of other statistical measures,such as, mean or 85th percentile? (The staff has selected probability of exceedance levels associated with the median hazard analysis estimates as they provide more stable estimates of controlling earthquakes.)

l 4. Should the median target level of IE-4 for LLNL or 3E-5 for EPRI 1 be raised or lowered, that is, should the next generation of nuclear power j plants have design levels for seismic events approximately equal to, greater j than, or less than the current nuclear power plants?

l 5. The proposed Appendix B has included a criterion that states: "the 3 probability of exceeding the Safe Shutdown Earthquake Ground Motion is j considered acceptably low if it is less than the median probability computed

from the current (EFFECTIVE DATE OF THE REGULATION) population of nuclear

Power plants". This is a relative criterion without any specific numerical I

value of the probability of exceedance. Because cf the current status of the probabilistic seismic hazard analysis, method dependent probabilities or

! target levels are identified in the proposeri regulatory guide. Coments are 4

solicited as to whether the above criterion, as stated, needs to be included in the regulation and, if not, should it be included in the regulation in a different form (e.g., a specific numerical value).

6. For the probabilistic analysis, how many controlling earthquakes should be generated to cover the frequency band of concern for nuclear power plants? (For the four trial plants used to develop the criteria presented in Draft Regulatory Guide DG-1015, the average of results for the 5 Hz and 10 Hz spectral velocities was used to establish the probability of exceedance level.

Controlling earthquakes were evaluated for this frequency band, for the average of I and 2.5 Hz spectral responses, and for peak ground acceleration.)

XII. Finding of No Significant Environmental Impact: Availability The Commission has determined under ine National Environmental Policy Act of 1969, as amended, and the Cosmiir,sion's regulations in Subpart A of 10 CFR Part 51, that this proposed regulation, if adopted, would not be a major Federal action significantly affecting the quality of the human environment and therefore an environner?a1 impact statement is not required.

The revisions a m etated with the reactor siting criteria in 10 CFR Part 100 and the relocation of the plant design requirements from 10 CFR Part 100 to 10 CFR Part 50 have been evaluated against the current requirements. The Commig,*e -NRS has concluded that relocating the requirement for a dose calculation to Part 50 and adding more specific site criteria to Part 100 does not decrease the protection of the public health and safety over the current regulations.

The proposed amendments do not affect nonradiological plant effluents and have no other environmental-impact.

The addition of Appendix 8 to 10 CFR Part 100, and the addition of Appendix 5 to 10 CFR Part 50, will not change the radiological environmental impact offsite. Onsite occupational radiation exposure associated with  !

l FRN - 23 '

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. y l& d this bsandary ISnuld be CIntIAed N N MtMattd'6Eber f 1", ec ruche cense plot er 4d. oukr edge. 4 de- new 8 + Nic acleic>n AceN whIthevec is correcE. 3 )

i the thyroid from iodine exposure. -

} (ii) An individual located at any point on the outer radius of a i .. low population zone who is exposed to the radioactive cloud resulting from the

! postulated fission product release (during the entire period of its passage) i would not receive a total radiation dose to the whole body in excess of 25 rem

! or a total radiation dose in excess of 300 rem to the thyroid from iodine exposure.

1 i 1.9 miles is Forassumed. purposes of this evaluation, a low population zone boundary of __I

} 1e 6 the a(iii) With respect to operation at the projected initial power '

i' paragraphs (pplicant is required to submit information prescribed in i a)(2) through (a)(8) of this section, as well as the information j required by this paragraph, in support of the application for a construction permit. ,

i l A NOTE:

March 23,Reference 1962, which is made to Technical Information Document (TID 14844, dated contains a fission

} which has been used in past evaluations. product release into con)ta i The fission product release given in 1 TID-14844 may be used as a point of departure upon consideration of severe accident research insights available since its issuance upon consideration of j l 4 plant design features intended to mitigate the consequen,ces of accidents, or  ;

! upon characteristics of a particular reactor. Copies of Technical Information  !

! Document 14844 may be obtained from the Commission's Public Document Room, l 2120 L Street, NW. (Lower Level), Washington, DC., or by writing the Director '

2 DC.Nuclear of 20555. Reactor Regulation, U.S. Nuclear Regulatory Consiission, Washington, i i (12) On or after

{

• apply for a construction [ permit pursuant to this part, or a designE i certification or combined license pursuant to Part 52 of this chapter, as i partial conformance to General Design Criterion 2 of Appendix A to this part, <

l shall comply with the earthquake engineering criteria in Appendix S of this part.

(b)

• l (10) On or after [ EFFECTIVE DATE OF THE REGULATION applicants who apply for an operating license pursuant to this part, or a), design certification or combined license pursuant to Part 52 of this chapter, as

partial conformance to General Design Criterion 2 of Appendix A to this part, shall comply with the earthquake engineering criteria of Appendix S to this part.

i However, if the construction permit was issued prior to EFFECTIVE DATE OF THE REGULATION), the applicant shall comply with the earthqua[ke engine criteria in Section VI of Appendix A to Part 100 of this chapter.

e e e e * *

5. In 550.54, paragraph (ee) is added to read as follows:

550.54 Conditions of licenses.

features with respect to postulated reactor accidents, in order to assure that such dostgns provide assurance of low risk of public suposure to radiation, in the event of such accidents.

FRN - 28

1a -

i PART 100 - REACTOR SITE CRITERIA -

. 10. The authority citation for Part 100 continues to read as follows:

I 1 AUTHORITY: Secs.103,104,161,182, 68 Stat. 936, 937, 948, 953, as 1 amended (42 U.S.C. 2133, 2134, 2201, 2232); sec. 201, as amended, 202, 88 g Stat. 1242, as amended, 1244 (42 U.S.C. 5841, S842).

11. The table of contents for Part 100 is revised to read as follows:

l PART 100 - REACTOR SITE CRITERIA i Sec. 100.1 Purpose.

j! 100.2 Scope.

! 100.3 Definitions.

100.8 Information collection requirements: OMB approval.

i Subpart A -

Evaluation Factors for Stationary Power Reactor Site Applications before [ EFFECTIVE DATE OF THIS REGULATION) and for Test Reactors.

100.10 Factors to be considered when evaluating sites.

100.11 Determination of exclusion area, low population zone, and population center distance.

Subpart 8 -

Evaluation Factors for Stationary Power Reactor Site Applications on or after (EFFECTIVE DATE OF THIS REGULATION).

100.20 Factors to be considered when evaluating sites.

100.21 Determination of exclusion area and population distribution.

100.22 Evaluation of potential man-related hazards.

APPENDIX A - Seismic and Geologic Siting Criteria for Nuclear Power Plants.

APPENDIX B - Criteria for the Seismic and Geologic Siting of Nuclear Power Plants en er dite [erreenve ww oF WS ltEGutATMM",} .

12. Section 100.2 is revised to read as follows:

5100.1 Purpose.

(a) This part sets forth standards for evaluation of the suitability of proposed sites for stationary power and testing reactors subject to Part 50 or Part 52 of this chapter.

(b) This part identifies the factors considered by the Commission in the evaluation of reactor sites and the standards used in approving or disapproving proposed sites.

13. Section 100.2 is revised to read as follows:

5100.2 Scope.

(a) This part applies to applications filed under Part 50 or Part 52 of this chapter for early site pemit,-construction pemit, operating license, or FRN - 33

~

upon consideration of population distribution. Political boundaries are not controlling in the application of this guide. Where very large cities are involved, a greater distance may be necessary because of total integrated population dose consideration.

(b) For sites for multiple reactor facilities consideration should be given to the following:

(1) If the reactors are independent to the extent that an accident in one reactor would not initiate an accident in another, the size of the exclusion area, low population zone and population center distance shall be fulfilled with respect to each reactor individually.JThe calculated envelopes (or each of tne plants areas snall be overlayed of the areas such that the 4 Qutermost composite houndarv shall then be taken as the olant boundary. a (2) If the reactors are interconnected to the extent that an accident in one reactor could affect the safety of operation of any other, the size of the exclusion area, low population zone and population center distance shall be based upon the assumption that all interconnected reactors emit their postulated fission product releases simultaneously. This requirement may be reduced in relation to the degree of coupling between reactors, the probability of concomitant accidents and the probability that an individual would not be exposed to the radiation effects from simultaneous releases. The applicant would be expected to justify to the satisfaction of the Commission the basis for such a reduction in the source term.

(3) The applicant is expected to show that the simultaneous oparation of multiple reactors at a site will not result in total radioactive effluent releases beyond the allowable limits of applicable regulations.

NOTE: For further guidance in developing the exclusion area, the low population zone, and the population center distance, reference is made to Technical Information Document 14844, dated March 23, 1962, which contains a procedural method and a sample calculation that result in distances roughly reflecting current siting practices of the Commission. The calculations described in Technical Information Document 14844 may be used as a point of c!aparture for consideration of particular site requirements which may result from evaluation of the characteristics of a particular reactor, its purpose and method of operation. Copies of Technical Information Document 14844 may be obtained from the Comission's Public Document Room, 2120 L Street, NW. (Lower Level),

Washington, DC, or by writing the Director of Nuclear Reactor Regulation, U.S.

Nuclear Regulatory Commission, Washington, DC. 20555.

rewclit io d ide.nkled 4e cumeni bt ico . _

FRN - 37

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19. Subpart B (5 5100.20 - 100.22) is added to read as follows:

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Subpart B - Evaluation Factors for Stationary Power Reactor Site Applications on or after (EFFECTIVE DATE OF REGULATION).

j 1100.20 Factors to be considered when evaluating sites. l The Comission will take the following factors into consideration in j

determining the acceptability of a site for a stationary power reactor:

j (a) Population density and use characteristics of the site environs,

including the exclusion area, the population distribution, and the compatibility of the site with the development of an emergency plan. >

i (b) The nature and proximity of man-related hazards (e.g. airports, dams, transportation routes, military and che:sical facilities).

(c) Physical characteristics of the site, including seismology,

! meteorology, geology, and hydrology.

j (1) Appendix 8 " Criteria for the Seismic and Geologic Siting of 1-Nuclear Power Plants After (Effective Date)," describes the criteria and nature of investigations required to obtain the geologic and seismic data necessary to l determine site suitability. mst (2) Meteorological charact ristics of the site that are necessary i for safety analysis or that may have an spact upon plant design (such as maximum probable wind speed and precipitation) be identified and characterized.

] (3) Factors important to h drological radionuclide transport (such l j as soil, sediment, and rock characteristics, adsorption and retention i

coefficients, ground water velocity, and distances to the nearest surface body j of water) should be obtained from on-site measurements. The maximum probable flood along with the potential for seismic induced floods discussed in Appendix B}eheeldbeestimatedusinghistoricaldata. l l 1100.21 Determination of exclusion area and population distribution.

i m ot-i (a) Each reactor fac111tygeha34 have an exclusion area, as defined in j 1100.3(a) of this part. f. m si- l 1

exclusion area)

(1 kingle reactor facility, the distance to the nt boundwy (as measured at any po<

from the reactor center point)For sites shall be at least 0.4 miles (640 meters). wst w,p j

(2)Forsiteswithmul tiple reactor facilinies, considerationg.

1 be given to the following: If t is reactors are inderendent to the extent that2 . l i

anaccidentinonereactorwoulgnotinitiateanace' dent in another, the size of each exclusion area 4ha44be determined withf re:pect to each reactor i

individually. The exclusion area for the site she44then be taken as the plan overlay of the sum of the exclusion areas for each reactor. If the reactors are j

interconnectedtotheextentthatanaccidentinonereactorwouldinjttatean accident inon determined another a case,the size basis.

by case of the exclusion area for each reactor whe n be l b1 wstJ ,

values (g)v(en) i If the offsite in paragraph population (b)(2) of this density section,atthe thesite proposed site exceeds the l by the Comission unless the applicant demonstrates either:gnot be approved L will i' (i) That there are no reasonably available alternative sites with significantly lower population densities, or (ii) That the proposed site is preferred over an alternative site with significantly lower population density on the basis of other considerations... - . - . - - - -

FRN - 38

t (2) The population density, including weighted transient populat' ion, projected at the time of initial site approval or early site permit renewal

should not exceed 500 people per square mile averaged over any radial distance i out to 30 miles (cumulative population at a distance divided by the total circular area at that distance). The projected population density, including weighted transient population, 40 years after the time of initial site approval <

j or early site pemit renewal should not exceed 1000 people per square mile  !

averaged over any radial distance out to 30 miles.

(3) Transient population must be included for those sites where a 1 significant number of people other than those just passing through the area) work, reside part-time, or (engage in recreational activities and are not permanent residents of the area. The transient population should be considered 4 for siting purposes by weighting the transient population according to the 4 i

' fraction of the time the transients are in the area. I i

(c) Physical characteristics of the proposed site, such as egress limitations from the area surrounding the site, that could pose a significant (

j impediment to the development of emergency plans,"b-ehell be identified.

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! 1100.22 Evaluation of Man-related Hazards.

}

(a) Potential hazards to the plant from man-related activities d associated with nearby transportation routes, military, and industrial facilities w&"-It be identified and their potential effects evaluated. Potential hazards to i the plant include such effects as explosions, fires, toxic and/or flamable

' chemical releases, dans (both upstream and downstream), pipeline accidents, and t aircraft crashes and impacts.

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" D (b) The effects of offsite hazards xsha44 have a very low probability of affet ting the safety of the plant. The likelihood and consequences of offsite l t

hazardskMbe estimated using data and assumptions that are as realistic and l

, representative of the site as is practical. The design bases for which the plant is " " " designed'+he4& be specified. j

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20. Appendix B to Part 100 is added to read as follows:

APPENDIX B TO PART 100 - CRITERIA FOR THE SEISMIC AND GEOLOGIC SITING OF NUCLEARR0WERW. ANTS'AFTER[EFFECTIVEDATg

{gg j OF M5 RE6uLA*nchl l'J '

General Information 4

' This appendix applies to applicants who apply for an early site permit or ,

combined license pursuant to Part 52 of this chapter, or a construction permit '

or operating license pursuant to Part 50 of this chapter on or after (EFFECTIVE DATE OF THIS REGULATION). However, if the construction pemit was issued prior to [ EFFECTIVE DATE OF THIS REGULATION), cha operating license applicant shall comply with the seismic and geologic siting criteria in Appendix A to Part 100 of this chapter.

I. Purpose i

General Design criterion 2 of Appendix A to Part 50 of this chapter requires that nuclear power plant structures, systems, and components important to safety be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss of FRN - 3g

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a _

l' 1 4.2 Cumulative Absolute Velocity (CAV) Limit f 2 j 3 The CAV should be calculated as follows: For each component of l 4 the free-field ground motion, (1) the absolute acceleration (g l 5 units) time-history is segmented into 1-second intervals, (2) 6 each 1-second interval that has at least 1 exceedance of 0.025g is

]

j .7 integrated over time, (3) all the integrated values are summed l 8 together te arrive at the CAV. Additional guidance on how to

9 determine the CAV is provided in EPRI TR-100082. i j 10 o l 11 The CAV Limit is exceeded if any CAV calculation is greater than j 12 0.16 g-second.

13

! 14 4.3 Instrument Operability Check I 15

! 16 After an earthquake at the plant site, the response spectrum and i 17 CAV should be obtained using the calibration standard (see j 18 Regulatory Position 1.1(4)) to demonstrate that the system was

! 19 functioning properly.

20 21 5. Criteria for plant Shutdown 22 23 If the 08E vibratory ground motion is exceeded or significant plant 24 damage occurs, the plant must be shut down.

25 26 5.1 OBE Exceedance. If the response spectrum check and the CAV limit, 27 performed in accordance with Regulatory Position 4.1 and 4.2, were 28 exceeded, the 08E was exceeded and plant shutdown is required. If 29 either limit does not exceed the criterion, the earthquake motion 30 did not exceed the 08E. The determinttion of whether or not the 31 08E has been exceeded should be performed even if the plant 32 automatically trips off-line as a result of the earthquake, or 33 9

34 5.2 Damagt. The plant should shutdown if the walkdown inspections, 35 performed in accordance with Regulatory Position 2 (Section 4.3.2 '

of EPRI NP-6695), discover damage.

J 36 37

) Wrk M 4ke. P/RJ guidanc.c. ccVers 44 e+pMal clete,ils needed j DG-1017 - 7  % emnet At p\ad egu'9med WII O nLMon aediGcah A re,a. in se'5mic. endrement (41,nilac 4e.Aere. wcMatW4 A-4

• 6eismit-mh> oceeduces We

ement. a

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i .

l j

• in different frequency bands, these earthquakes should be j specified. The description of the potential earthquake (s) is to i include the maximum intensity or magnitude and the distance from j 4 the assumed location of the potential earthquake (s) to the site.

j 5 For the seismotectonic province surrounding the site, the DSE is

] 6 assumed to occur within 25 km of the site. The staff independently j 7 evaluates the site ground motion produced by the 1;;;;;t :::thq::h:

! 8 DSE associated with each g::1:gi: :tructur: :: t::t:ni: p ;;in :

j 9 seismic source. Controlling earthquakes (CE) are those earthquakes

10 that have the greatest effect on the ground motion at the nuclear 1 11 power plant site. Acceptance of the description of the p

::nti:1

] 12 controlling earthquake (s) that would produce the largest ground i 13 motion at the site is based on the staff's independent analysis.

1

14 2.5.2.5 Seismic Wave Transmission characteristics of the site, j 15 In meeting the requirements of Reference 1, this subsection is j 16 accepted when the seismic wave transmission characteristics i 17 (amplification or deamplification) . of the materials overlying

18 bedrock at the site are described as a function of the significant j 19 frequencies. The following material properties should be

20 determined for each stratum under the site

seismic compressional j 21 and shear wave velocities, bulk densities, soil index properties

22 and classification, shear modulus and damping variations with j 23 strain level, and water table elevation and its variation. In each 24 case, methods used to determine the properties should be described 7' in subsection 2.5.4 of the SAR and cross-referenced in this subsection. For the . ;=1;;  ;;rthqu;h

controlling earthquake, i determined in Subsection 2.5.2.4, the free-field ground motion j 28 (including significant frequencies) must be determined, and an

! 29 analysis should be performed to determine the site effects on  ;

j 30 dif ferent seismic wave types in the significant frequency bands. l l 31 If appropriate, the analysis should consider the effects of site i j 32 conditions and material property variations upon wave propagation  ;

33 and frequency content.

i 34 The free-field ground motion (also referred to as control motion) 35 should be defined to be on a ground surface and should be based on l 36 data obtained in the free field. Two cases are identified

37 depending on the soil characteristics at the site and subject to 2

38 availability of appropriate recorded ground-motion data. When data 4 39 are available, for example, for relatively uniform sites of soil or

40 rock with smooth variation of properties with depth, the control l 41 point (location at which the control motion is applied) should be 4 42 specified on the soil surface at the top of the finished grade.

43 The free-field ground motion or control motion should be consistent i 44 with the properties of the soil profile. For sites composed of one

! 45 or more thin soil layers' overlying a competent material, or in case j 46 of insufficient recorded ground-motion data, the control point is 4 47 specified on an outcrop or a hypothetical outcrop at a location on i 48 the top of the competent material. The control motion specified

) 4e should be consistent with the properties of the competent material.

a 3

rebruary 10, 1992 M s W yado th e ns d % m M % n . h j 2.5.2-7 Mnd yade. IS dito di b t d*P60 dI9 0h *b b W1 dine h rdecced 4o. A deNbn d ' finished yade_"

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