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x--x gN}w Depa ent of C erce NEAL L. MOYLAN xgyaggac7ce%3tM."cKX2DcMtMM00QMK Albany, N.Y.12207 COM MISSIONER OP' COMMERCE 1 I. T / /. 74Tanuary 26, 1972, A @4(/ 4.
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I.T Mr. Woodford B. McCool B.,'/
dj Secretary U.
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l Washington, D.
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20545 i,
q Attention Mr. Stanley T.
Robinson, Chief
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Public Proceedings Branch Sp/4/
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Dear Sir:
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Members of the New York State Atomic Energy Council and the New York State Geological Survey have reviewed the proposed amendments to regulations in 10 CFR Part 100,
" Reactor Site Criteria", which the U. S. Atomic Energy Com-mission (U.S. AEC) has under consideration.
The amendments would add an Appendix A entitled " Seismic and Geologic Siting Criteria for Nuclear Power Plants".
Based upon our review, we support the adoption of the proposed Appendix A by the Commission.
We do, however, wish to offer the following comments concerning this proposed Appendix A.
The U.S. AEC has appropriately proposed seismic and geologic siting criteria.
It is felt that the Commission should also establish similar siting criteria with regard to meteorology and hydrology.
Also, in all proposed additions and modifications to U.S. AEC regulations, the Commission should provide supplemental information explaining why a particular regulatory approach was selected.
For example, an explanation of how the numerical values for the criteria in proposed Appendix A were selected would have been helpful.
Geologic and Seismologic conditions are so diverse that it is impossible to erect a rigid set of nuclear plant siting criteria that would be nationally applicable.
The proposed Appendix A recognizes this difficulty and wisely prescribes the type of information which should be included in a siting evaluation, but does not invoke arbitrary specifica-tions such as a constant distance from the closest known fault, etc.
Each siting decision must be made on the basis of the unique conditions associated with each application.
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i Mr. Woodford B. McCool January 26, 1972 Unfortunately, siting decisions have to be made while scientific understanding of the causes of earthquake.s and their relationship to faulting are not completely understood.
This means that the only practical approach is an empirical one asking the question:
what has happened in the past geologically and seismologically, and what does this imply is probable during the future?
Thore are two handicaps to this approach that should be pointed out immediately.
These are deficiencies in the state of the sciences rather than the siting criteria.
1.
The relationship between faulting and seismicity is poorly understood in many areas; there are numerous areas where seismic activities cannot be directly attributed to geologic structures.
The approach of the " safe shutdown earthquake" which supposes direct correlation with a specific fault system or tectonic province is not entirely satisfactory in such areas.
2.
The maximum historically observed earthquake magni-tude is not always a valid guide to the largest event which may occur in the future.
In general it is felt the U. S. Atomic Energy Commission should confer with the applicant at several prescribed times while the applicant is preparing geologic and seismic data so that mutual agreement can be reached at as early a stage as i
possible on which characteristics of the terrain surrounding the site should be examined in greatest detail.
The host state should also have an opportunity for such discussions.
By lack of comment on this point in Appendix A, it may be implied that there is no upper limit to a safe shutdown earth-quake and that engineering design can cope with any acceleration.
We doubt that this is true and suggest there must be a threshold above which anticipated earthquake accelerations would endanger survival of any structures and their support system sufficiently to warrant rejection of an application.
This threshold should..be considered in Appendix A.
The remainder of these comments are in outline form corresponding to the sections in Appendix A.
III.
Definitions (g) (1) active fault:
In many casco it will be difficult to identity active faults".
This is especially true in parts of the country where little stratigraphic evidence is available to assess fault offset during the last 35,000 - 500,000 years.
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- l Mr. Woodford B. McCool
-3 January 26, 1972 l
III.
(k)
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One:. The concept of " control l width" should include j
not only those faults which join the main fault 1
along its trace, but also those that join or are associated with the main fault at depth, such as auxiliary,; antithetic or g1 dchelon faults.
There is also some. confusion concerning the use of the d'
term control width.
~ The following addition is suggested for section III - (k) :
The term " preliminary ' control' width" is used for the original conception of the span of the faulting perpendicular to~the trend of the structure.
l After field analysis in.section IV (b), this ~ figure-may be. amended on the basis of new; data to a dif fer-ent dimension known as the " established control width".
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In IV (b) (6). (iv), this sentence should be l
added:
"These limits are the established control
?
width".
In V,(b) line 21, it shonld read:
...previously:
recognized, the preliminary control width of...".
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Two:
If the system of faults is.not vertical or if l
some of the faults within the system are not vertical, the control width should include the areas at the l
surface under which these faults are projected.
Three:
Where possible, the three-dimensional con-figuration and the projected three-dimensional models of the fault or. tectonic system should be considered as well as the surface traces of the-faults within the zone.
IV.
Regional Investigations (a) (1), (3), and (4):
The word " determination" should be replaced by the word " evaluation".
l (a). (5)'s The listing of all historically recorded earth-quakes should include examination of seismic stations -
having unpublished records where they are appropriate in determining the' seismicity of the region.
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1 Mr. Woodford B. McCool January 26, 1972 (a) (6):
Problems in assigning seismic activity to speci-fic faults were discussed in the first part of these comments.
In tectonic provinces designated " stable platform" with only very slight structural features there are seismically active areas where many earthquakes cannot be attributed to individual structures.
(a) (7) :
There are three problems:
one:
In determining those which are " active faults" in some structurally complicated areas, sufficiently l
detailed geologic maps are not available which would I
provide the structural detail desired.
l Two:
Footnote 2 on Federal gpgister pages 22,602 and 3 and 4 on page 22,603 are somewhat circular in reasoning.
For example, footnote 2, "If the safe l
shutdown earthquake can be associated with the fault closer than 200 miles to the site, the procedures of I
subparagraph IV (a) (7) and IV (a) (8) need not be carried out for more remote faults".
Yet section V (a) (1) states " Determination of safe shutdown earthquake.
The safe shutdown earthquake should be l
identified through evaluation of seismic and geologic l
information developed pursuant to the requirements of IV (a) as follows...
In addition for active faults, information required by subparagraph IV (a) (8) should also be taken into account in determining the earthquakes of greatest magnitude related to the faults. "
How can the safe shutdown earthquake be determined without s'teps IV (a) (7) and IV (a) (8) ?
Section IV (a) (7) is intended to require an in-ventory of faults peripheral to the proposed plant site.
In table 1 guidelines are presented for the selection of faults which will be studied and reported l
on in detail as outlined in section IV (a) (8).
We propose that a conference between the applicant and the Atomic Energy Commission and appropriate state i
scientific personnel follow inventorying of section IV (a) (7) nnd at that time those faults requiring detailed description to comply with section IV (a)
(8) be identified.
This avoids the difficulties of an inflexible table such as table 1.
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j Mr. Woodford B. McCool January.26, 1972 Three:
In table 1 the title for the second column-
'l should be changed to. read " Minimum length of fault (miles) which.must be considertid in establishing safe shutdown earthquake".
IV.
- (b) :
These same observations apply here as already j
alluded to in IV (a).
IV. (c).(ii):
In outlining investigations required in connection' with seismically induced floods ~ or waterwaves, 'the.
regulations state that local'aite' features might, tend J
to modify tsunami runup'or drawdown.
The proposed investigative" requirements are clear, but there seems to be no adequate guidance ;on. how the information
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developed in such investigations is to be.used in-dealing with engineering decisions' involving a hypo-thetical tsunami.
V.
Seismic and Geological Design Bases Most of the provisions in this section have been discussed in the comments in sections IV (a) and (b) above.
Several other observations'are required:
one:
The designation of a " safe shutdown earthquake" should include a margin of safety above the historically-determined maximum vibratory ground motion expected at the site.
It cannot be assumed that the largest event possible has already occurred and been: recorded.
A basis for requiring nuclear power plant shutdown J
is set forth under paragraph V.
(a) (2).
This section should contain or reference the U.S. AEC regulations
-which specify the conditions under which a plant' shutdown is to be actuated (manually or automatically) and the type of ~ sensing. equipment necessary, to achieve the shutdown.
Two:
The faulting of the region should be studied > in -
c the sub-surface as well as at,the. surface - if 'well' records are available.
If this is done the geometry of the faulting in three-dimensions ~provides a much.
i more definitive conception of the structuro which can be related to the earthquakes.
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Mr. Woodford B. McCool January 26, 1972 Three:
In shallow drilling to rock for nuclear site design in some areas, unexplainable broccia zones have been encountered.
Additional drilling should be required to determine the nature of such breccia and no approval of the location granted until the age of the breccia, the offset which may exist and the relationships to the other structures of the region are assessed.
More stress should be given than is provided in V (d) (i) and (c) (ii).
Four:
In many " stable platform" areas, faults and monoclines are related to " basement" structure.
If salt is present in the column above the " basement",
the plasticity of the salt may greatly change the geometry of faulting so that structural character below the salt is significantly different than above.
In such cases where well data are available, structure contour work should be done below and above the fault to evaluate the influence of the salt upon the structure.
Special attention should be given to solution salt mining if this is present in the region.
Section V (d) (1) ti) (b) should be also expanded to include monitoring of seismic character of the region where withdrawal or injection of fluids is taking place, bcth before the process begins to determine the natural seismic character of the area, and during the process to determine the changes in seismic character that may result from such a process.
Five:
Section V (d) (1) (iv) - Residual stress should be carefully examined in areas where quarry
" pop ups" and other phenomena suggest horizontal l
stresses at the surface.
I Six:
Section V (d) (3) should be more explicit l
about requirements for determining the " safe shutdown earthquake" for auxiliary constructed structures, such as cooling water impoundment dams, which may be some considerable distance from the reactor site and in a different tectonic zone or near a different fault zone with a different " control width".
f VI.-
Engineering design criteria l
(a) (1):
The phrase "it usually will be appropriate" in the last sentence of the first paragraph of section l
VI. (a) (1) should be changed to "it may be. appropriate" l
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Mr. Woodford B. McCool January 26, 1972 1
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'because smoothed response spectra envelopes in
,present usage and the ability to generato artificial l
earthquakes which correspond closely to response spectra envelopes negate the need for using several
' time histories.
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l (a) (2) :
l The. phrase "necessary for power generation"~
needs clarification..
I On behalf of the New York State Atomic Energy Council I l
would like to express our appreciation for being able to parti-f cipate'with the Commission in this matter.
Cordial Neal.L. Moy n
I chairman New York State Atomic Energy Council cc Members of the New York State Atomic Energy Council New York State Geological Survey I
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