ML19341A797

From kanterella
Jump to navigation Jump to search
Answers & Objections to New England Coalition on Nuclear Power Interrogatories.Certificate of Svc Encl
ML19341A797
Person / Time
Site: Seabrook  NextEra Energy icon.png
Issue date: 01/21/1981
From: Dignan T, Vandenburgh D
DIGNAN, T.G., PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:
NEW ENGLAND COALITION ON NUCLEAR POLLUTION
References
NUDOCS 8101280091
Download: ML19341A797 (20)


Text

{{#Wiki_filter:,la r le i P- e

                                                                                        <.9 03 UNITED STATES OF AMERICA                        .. a                          __
                                                                                  ;--       J A N .,. A 1981 >
                                                                                                                ~  ;

NUCLEAR REGULATORY COMMISSION d 'otte : te Secretarf / l 2.- , ' iea:= {\ before the 4 p

                                                                                                       ~~

ATOMIC SAFETY AND LICENSING APPEAL BOARD

                                                            )

In the Matter of )

                                                            )

PU3LIC SERVICE CCMPANY OF NEW ) Docket Nos. 50-443 HAMPSHIRE, et al. ) 50-444

                                                            )

(Seabrook Station, Units 1 & 2) )

                                                            )

PERMITTEES' ANSWERS AND OBJECTIONS TO INTERROGATORIES OF NECNP Q.l. Please identify everyone whon the Applicant expects to call as a witness in the renanded phase of the Sea' crook pro-ceedings on seismic issues. A.l. Richard J. Holt. Q.2. With respect to each witness identified abcv? 3 please:

a. Describe the extent of the witness' previous involvenent in the Seabrook proceedings, if any. This description should include not only whether the witness has previously testi-fied, but also whether the witness has advised the Applicant on seisnic issues in the past and the substance of that advice.
b. Identify all NRC hearings, trials, and other adjudications in which the witness has provided testinony, including the date and location of the testinony, a brief desqription of the substance of the tbsti.? .
                                                                           ,  ',the behalf
                                                                               ,         identity    the and interest of the                       o .

test!=ony was provid $ pas,)* Ys

                                                        ~
                                                         . :-   . g"f r.
                                                                      ,t f}t;f ,9
                                                                          ~
                                                                                       .9{.
                                                                  .')I' .3 ; i ( g-
                                                                                       ~

u.a. nL% > .'.o',~ 9'/ ) )t O

                                                             ,.                  .<s, s,                 +

3 ' O I 2 8007/ 6-

c. Identify and provide copies of any analyses that have been performed by the witness concerning Dr. Chinnery's methodology for determining earthquake intensity and prob-ability in general and for the Seabrook site in particular.
d. Identify and provide copies of any analyses that have been performed by the witness concerning Dr. Trifunac's approach to determining vibratory ground motion or his conclusions concerning ground acceleration at the Seabrook site.

e, If the witness was one of the experts solicited by the NRC for its Seismic Hazard Analysis, NUREG/CR-582, identify the witness' responses-in that document. A.2.a. Mr. Holt testified in the State of New Hampshire environmental hearings before the N.H.S.E.C.; he also testified in the NRC hearings before the ASLB. Mr. Holt's advice and testimony are a matter of record. A.2.b. Mr. Holt, in addition to Seabrook, has appeared before the ASL3 and State of New York environmental hear-ings for the proposed Green County Nuclear Power Plant on July 22, 25, 2c, 1977, Albany, New York. Mr. Holt served as an expert in seismology and seismic field measurements at the Green County hearings on behalf of the Power Authority of the State of New York. In March of 1973 at Cambridge, Massachusetts, Mr. Holt testified in the Pilgrim II proceedings before the ASLB. His testimony supported the selected design basis for the plant. l A.2.c. No analyses of the type described have been performed as of this time.

                                                                                 )

1 A.2.d. No analyses of the type described have been performed as of this tiSe. In connection with this answer, the following [ l should be noted: l l l i i

The peak acceleration for the Sea brook site was selected before the Trifunac & Brady relationship was published. Subsequent to the submission various relationships have been developed by Trifunac & Brady (1975) and O'Brien, Murphy & Lahoud (1976). These relationships did not require changing the selected acceleration for Seabrook and no further work was per-formed. Trifunac, M. D. and A. G. Brady, (1975), "On the Correlation of Seismic Intensity Scales with Peaks of Recorded Strong Ground Motion", Bulletin of the Seismological Society of America, p. 65 J. R. Murphy and L. J. O'Brien, 1978, " Analysis of a World-wide Strong Motion Data Sample to Develop an Improved Correlation Between Peak Acceleration, Seismic Intensity and Other Physical Parameters", NUREG-0402, prepared for U.S.N.R.C. by Computer Sciences Corporation. A.2.e. 3. Q.3. Is it the Applicant's position that an eartnquake of Intensity IX on the Modified Mer:alli scale is impossible at the Seabrook site? A.3 Nothing is impossible; as we have stated, we believe that MMI IX shaking on the Seabrook bedrock is inconceivable. Q.4 Is it the Applicant's position that an earthquake of Intensity IX is impossible in the tectonic province contain-ing the Seabrook site? A.4. No. Q.5 If the answer to either of the previous questions is that an Intensity IV earthquake is not impossible,

a. What does the Applicant believe to be the probability of occurrence of such an earth-quake?

! 1 i

1

b. What is the factual basis and rationale for that probability judgment?
c. What does the Applicant believe to be the earthq'uake of greatest intensity that can occur at the site or in the tectonic province?

d' . Please provide a detailed justification for the choice of maximum intensity earthquake. A.5.a. There is no existing evidence,either observational or geologicsl, for the occurrence of a MMI IX earthquake in New England. The potential occurrence of such an intensity could 1 be based on physical evidence or some extrapolation of the historical seismicity data base. Without physical evidence or a physical bases such a probability wculd have little or no absolute meaning. An extrapolation of historical data such as has been carried out by Dr. Chinnery, leads to curves which are not linear (see below Question lib) and widely varient in predicted return periods with relatively small changes in slope. The Applicant believes that such an earthquake, particularly on rock, is above the maximum earthquake for the site and a mean-ingful probability of occurrence cannot be calculated. A.5.b. See answer to 5.a. A.5.c. This does not specify. time. However, assuming that we are discussing the same geologic time period and the' processes associated with it, the largest intensity on site bedrock would be no more than VI-VII. On the same*assumptiens, we believe that Intensity VIII can occur on soil in the province, assuming that an intensity characterizing the earthquake is intended (1958, Gutenberg & Richter Elementary Seismology, 4-

pp. 135 and following) and not some isolated intensity value due to very poor soil conditions such as man-made fill. A.5.d. The maximum intensity earthquake is based on an assessment of tectonics and earthquakes of the northeastern United States together with the seismicity and geologic condi-tions in this region. The most recent comprehensive coverage of these subjects is given in the PSAR and amendments for Boston Edison's Pilgrim Unit I!. Q.6. If the answer to either or both of Questions 3 and 4 is that an Intensity IX earthquake is impossible, please provide a detailed justification for that conclusion. A.6. Not applicable. Q.7. Please identify and provide copies of all studies or analyses that give rise to or support the conclusions and justi-fication provided in response to Questions 3-6. A.7. These conclusions and any analyses are contained in the Seabrook PSAR and amendments, the Pilgrim II PSAR and amend-ments, as well as the NRC Site Evaluation Reports for both. These documents are available for copying in the NRC Public Docu-ment Room. Q.3. Please describe what the Applicant believes to be the tectonic province or seismic area in which the Seabrook site is located.

a. Please justify this choice in detail. In so doing, describe, explain the use of, and justify the Applicant's conclusions concern-ing, at a minimum, the following: -
1. All tectonic structures and other tectonic or seismic features, including all identi-fled fault lines, that the Applicant considered in reaching its conclusions.

i

                                                                               \

1

2. Any new information concerning tec- l tonic or seismic features or activity in the Northeastern United States that has become known to the Applicant since its original testimony on seismic issues in this proceeding.

3 All historical earthquakes considered by the Applicant, including their intensity on the Modified Mercalli scale. 4 The " Boston-Ottawa seismic trend."

b. Please explain the relevance of this choice of tectonic province to the determination of the design basis earthquake, under the methodology propounded by the Applicant.
c. Please identify and describe the sources from which you have compiled a historical record of earthquakes in the tectonic pro-vince or seismic area described in response

, to this question. In particular, how complete is the record as a function of time, location within the province er area, and intensity. Obj. 3. Interrogatory No. 8 is objected to as being irrelevant Oc any issue before the Board. The reopened proceed-ing was ordered with respect to two issues; a relitigation of the proper tec:cnic province or seismic area was not one of them. Q.9. d'as the Applicant or any of its witnesses examined other possible tectonic province choices for the area?

a. If so, please describe each one and explain in detail why it was rejected in favo9 of that described in response .to Question 8.

Obj. 9. Interrogatory No. 9 is objected to for the same reasons as set forth above with respect to No. 8. , Q.10. Is it the Applicant's position that the location of the Seabrook site within a particular tectonic province or other seismic area determines the maximum intensity earthquake that could affect the Seabrook site?

A.10. No. It is the Applicant's position that the tectonic province determines the maximum earthquake but any intensity value which results from it is greatly determined by the geologic materials of the site. Intensity values resulting from an earthquake will almost universally be lowest on rock and highest on poor soils. Q.ll. Does the Applicant contend that there is not a linear relationship between earthquake intensity and probability of occurrence, as posited by Dr. Chinnery?

a. If so, please provide the basis for that conclusion, including any ecpirical data that the Applicant contends refute Dr. Chinnery's linear hypothesis and other curves that the Applicant believes fit the available data,
b. If the Applicant accepts Dr. Chinnery's linear hypothesis to some extent, but not in its entirety, please explain where the Applicant disagrees with Dr. Chinnery's hypothesis, data, methodology, or conclu-sions.

A.ll. The linearity is unproven, particularly in inactive areas and for larger earthquakes. Without linearity of the curve, prediction of probability for the larger earthquake levels is too erratic to be useful. A.ll.a. The curve which Dr. Chinnery has produ'ed c is a plot of intensity (si:e) versus the number of earthquakes of a given size or larger per unit of time, per unit of area; the units of time and area which are chosen are judgmental. Only at the mid-intensity range (V-VII) does the curve appear to be linear. At the smaller intensities it is not linear and various schemes (Stepp, J. C., 1974) have been devised to make this s

      .                                                                                      \

I

        =   .

1 i portion linear. Although these smaller earthquakes do not concern us insofar as damage is concerned, they can greatly

              - influence the slope of the curve particularly in the absence of larger earthquakes.

Stepp, J. C., Analysis of Completeness of the Earthquake Sample in the Puget Sound Area, in Harding, S.T., Contributions to Seismic Zoning, U.S. Department of Commerce, NOAA Technical ReportERL2d7-ESL30,May,1973 We stated that the unit of time and area selected are i l judgmental. Reference is made to Dr. Chinnery's curve for the i

               " Mississippi Valley" area (see yigure 1) (A comparison of the t

4 Seismicity of Three Regions of the Eastern United States, Michael Chinnery, Eulletin of the Seismological Society of America, Vol. 69, No. 3, pp. 757-772, June, 1979). Dr. Chinnery has chosen to eliminate the largest events of the New Madrid area by selecting a 130-year period. [As a note, the intensity value of IX shown on this curve is from Nuttli; the U.S. Geological Survey carries this earthquake, October 31, 1395, as an Intensity VIII which would eliminate the point shown 4 at IX and leave the point shown as Intensity VIII as 'is]. Quite a different curve is developed if we include the 1811 series of earthquakes which range from X-XII which extends the

data base 39 years (see yigure 2). Obviously, this'second figure is not linear at the high intensity end of the data.

If the curve changes slope at the high intensity end then perhaps the larger faults which cause the larger earthquakes

                                               -S-                                           !

1 _ _ _ _. -_ .__ m I

act differently than smaller faults causing intermediate or lower size earthquakes. Also, the flatter the slope which appears at the high intensity end of the curve,the shorter the return period of large earthquakes cr the relationship of s= aller earthquakes to larger earthquakes, on a given fault, is quite different, if such a relationship exists at all. The other explanation, that used by Dr. Chinnery,is that tue time period

                 ~

we lockad at fortuitously included large earthquakes and if we chose Oc ignore them then the remainder of the curve tells us that the average return period for them is longer than observed history. It should be noted that geologic evidence for larger earthquakes abounds in the New Madrid area. Large earthquakes do not appear to be predictable in average time at least not from the historical seismicity data set. Another point which is apparent from the second curve is that an " upper bound" earthquake cannot be predicted from this type of curve. In a simplistic argument one can state that largar earth-quakes are une resui: of larger fault rupture. Since these larger earthquakes are the ones 'c are interested in, then the population of earthquakes used for a curve such as Dr. Chinnery has produced, should be drawn only from faults which can produce large earthquakes. If such faults had a linear distri-bution of different size earthquakes then the method might be useful. It appears from Figure 2 that this is not the ense and l the population of earthquakes from smaller faults may have characteristics unlike those of which result from larger faults. _g_

l l i A.11.b. The Applicant does not accept Dr. Chinnery's If a relative probability linear hypothesis (see Question 8). of occurrence at different sites is des! red then some sort of method such as linear extrapolation is appealing. However, the greatest cautien is advised, it is probable that a linear relationship, may only be valid at the mid-intensity range and even here it is probable that the slope of the curve changes Therefore, an agreed with time as.well as the area selected. upon slope must be employed. This slope would have to be dic-tated by a group of experts based on seismically active areas which may be totally unrelated to inactive areas. The amount of extrapolation to be employed would also have to be dictated. All of this, if done in the absence of the detailed site and regional geology would not only be misleading, it could be mis-leading in a very non-conservative nanner. For example, if the site were located near a ma'cr active fault the earthquake distribution of which in time is unknown, we would predict unrealistically long return periods or low probability of earth-quake occurrence. Shakal & Tackso:, 1977, Earthquake Hazard in New England Science, Vol. 195, N4274 In summary, it could be used in a relative sense if agreed upon values could be dictated by a group of experts and if these groups of experts had before them detailed knowledge of regional and site geology-geophysics and were certain they j could establish a normalized base for each site under considera-tion. Even with all of this it is doubtful that probability

4 within an order of magnitude or more could be established. ,

                                                                                        )

Q.12. Has the Applicant or any of its witnesses applied the Chinnery hypothesis and methodology to the Seabrook site using as a local data base tectonic provinces or seismic areas that differ frem the " Boston-New Hampshire area" used by Dr. Chinnery in his Statement en behalf of NECNP during the original Licensing Board hearings?

a. If so, what conclusions were reached?
b. In particular, to what extent, if any, did altering the size of the seismic area data base alter the slope of the probability-intensity curve?
c. Please provide a detailed justification for the choice of the seismic areas from which the local data base was drawn.
d. Please provide ccpies of all work papers involved in this analysis and of any resul:-

ing reports or studies. A.12. No. A.12.a.-d. Net applicable. Q.13 Please name one region in the world where it has been clearly and unequivocally demonstrated that an upper bound to earthquake size exists. What is the upper bound? How does the geological structure of this region compare with the New England area? Please give references. A.13 This question appears to ask for evidence of seme-thing that does not exist. There are areas of the world which, within historic times, have not suffered large earthquakes particularly those areas which are away from plate boundaries. Such areas have shown long geologic stability in that they

   -        are not being actively subjected to orogenic forces.          England and Ireland,to cite areas not unlike New England,have over a thousand years of history with the largest earthquake having been
  • Intensity VIII. See, for example, Seismicity and Seismic Hazard ,

1 1

                                                                                        )

l l

in Britian, Seismological Sulletin No. 4 of the Natural Environmental Research Ccuncil Institute of Geological Sciences by R. C. L11 wall. Without going into great detail,the tectonics of Scotland-Northern Ireland are characterized by long northeast trending faults of Caldonean age as is the case for New England. The lithologies are somewhat different; however, the mechanical prop-erties of.the racks, rigidities and seismic velocities should compare reasonably well. Such direct analogy of New England to any other part of the world was not involved in establish-ing the maximum earthquake for Seabrook. Additionally, it should be mentioned that over 99% of the worlds earthquakes occur over less than 10% of its area as listed by Lemnitz (Global Tectonics and Earthquake Risk - Elsevier, 1974, p. 157). Area  % of World Seismicity Circum - Pacific 3elt 75.o Alpede - Asiatic Belt 22.1 Ocean - Ridges 1.8 Total 99.5 Clearly this de= castrates that there are areas which are seismically active and others which are seismically inactive ~ within historic times. To extend the time base we' have recourse to geologic evidence. Active seismic areas such as mentioned above are characterized by areas of present mountain building with such characteristics as capable faulting volcanic and plutonic activity, etc. These processes are clear in the geologic evidence of several =(111cns of years. Conversely, there are areas whose tectonic stability *ss evidenced over many millions of years based _on geologic evidence. Q.14 Maximum possible earthquakes were given by each of the experts in NUREG/CR-1532 (Seismic Hazard Analysis Solicita-tien of Expert Opinion, TERA Corporation) for regions of New England. a, Where only magnitude is quoted, please state what the Applicant believes to be the maximum epicentral intensity of an earthquake of that magnitude. Please describe in detail the method and calculations used to convert from magnitude to intensity.

b. For each maximum possible earthquake stated by each expert for regions of New England, please state whether the Applicant agrees or disagrees with the selection and explain why.

A.14 The following Table summarizes the exparts' responses on the maximum possible earthquakes for the New England =cnes that contain the Seabrock site. (Note: the responses are to question 2-2 in EURE3/CE-1582 V:1. 3) 4 EXPERT NO. INTENSITY ESTIMATE COMMENTS 1 2 3 3 IX X XI Applican Disagrees

              '4                 VI       VIII      X       Applican   Agrees en 1, 2 5                            XII                         Disagrees 75                 3.9        9.3    9.9                 Disagrees 8*                            8.5                  "

Agrees 9* 7.9 a.9 9.9 " Agrees en 1 10 VI VIII XI on 1, 2 11* 3.5 9.5 10.5 " " en 1 12* 5.0 9.0 " " on 1 13 . IX X XI Disagrees

1. Lcwer Sound Estimate fcr unconstrained"-

time.

2. Best Estimate " "

3 Upper Sound Estimate .

  • Expert responded with mb-magnitude; intensity estimates were computed using I=2 x m -3 5 (Nu li and Herrmann, 1973).

s. Nuttli, 0:0c W., and Robert 3. Herrmann, 1973, " State-of-the-Art for Assessing Earthquake Ha:ards in the United States, Reper: 12 - Credible Earthquakes for the Central United States," U.S. Army Engineer Waterways Experiment Station Miscellaneous Paper S-73-1, Report 12. O.15 What, in your opinion, is the maximum epicentral intensity of the largest earthquake that will ever occur within the province or area described in resp 9nse to Question 3?

a. Please justify your answer in detail, includ-ing reference to all relevant tectonic strhe- '

tures, tecten-. cr seismic features, and historical earthquakes.

b. Explain why you are exactly 100% confident j that your answer is correct. If you are not exactly 100% ccnfident, state your degree of confidence, and explain how it was e,stimated.

Cbj. 15. Objection is T.ade to Interrogatory No. 15 for the same reascns as set forth with respect to Interrogatory No. 8 l l l and because it is dependent upon an answer having been given to l Number 8. 1

                                           -lh-

4 1 Q.16. Is it the Applicant's position that 10 CFR, Part 100, Appendix A, requires that the SSE be the largest earthquake that can be predicted with 1005 confidence ever to occur within the tectonic province containing the site? If not, what confidence level is acceptable for this selection, and how did you arrive at this level? Obj. J. Interrogatory No. 16 is objected to as calling for a legal conclusion, 1 g., an interpretation of the regula-tions. Q.17 .The Applicant's proposed SSE for the Seabrook site has a maximum epicentral intensity of VIII. On what ground conditiens is this defined? What is the magnitude of such an earthquake? A.17. The Applicant would contend that an Intensity VIII can only occur on poorer soils in New England. However, the maximum intensity was considered at the site irrespective of foundation conditions so that corresponding acceleration value associated with an Intensity VIII was assumed to occur on the bedrock of the site. The approximate mb magnitude of such an earthquake would be approximately 5.7 to 6. It should be mentioned that the SSE is defined by a response spectrum and to achieve this spectrum .25g was treated as an anchor point for a regulatory guide 1.60 spectral shape. The result of this is a spectrum that would most likely exceed the above-quoted magnitudes (or Intensity VIII) for rock founda-tien conditions. Q.lS. What is the total range of ground accelerations that have been observed from earthquakes of the magnitude quoted in question 17. How many of these were observed on bedrock? Please give references for these bedrock data. l A.lS. We are unable to respond to this interrogatory absent a good deal of compilation and retrieval of data. We are informed by counsel that no such duty is incumbent upon us. The data could be extracted (at least in part) by you from the following references:

1. Catalog of Seismograms and Strong-Motion Records, World Data Center A for Solid Earth Geophysics, Report SF-6 (May, 1977).
2. Chang, F. K., 1978, Catalog of Strong Motion Earthquake Records, Vol. 1, Western United States 1933-1971, Misc. Paper S-73-1, State-of-the-Art for Assessing Earthquake Hatards in the United States, Report 9, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss.

Q.19 Can the bedrock acceleration data in Question 13 be represented as a Gaussian distribution? What are the mean and standard deviation of these data? What is the probability that an earthquake of maximum epicentral Intensity VIII will generate a bedrock acceleration in excess of 0.25g? Please give details of the probability calculation. A.19 Probably a Gaussian distribution is not a good fit, a log-normal distribution is probably more appropriate. At the discrete Intensity VIII, Trifunac and Brady (1975), for example, show a mean value of .16g and a value of .25g at a standard deviation. This would result in a probability of 16% that the .25g would be exceeded or conversely 84% certain that the acceleration value would be .25g or less. It is worthy of note that no direct observation of inten-sity value at a given accelerometer station is correlated to i

acceleration. The intensity values are taken from the region surrounding such stations. 3ML E. e4% Donald :.. Vandenburgh Attorney Making Objections:

                                             ^ [f/f,f Tho5as G .' Dis;;Htfi, Jr.

COMMONWEALTH OF MASSACHUSETTS Middlesex, ss. JanuaryJl , 1931 Then appeared before me the above-subscribed DONALD E. VANDEN3URGH and made e ath that he was authori::ed to execute the foregoing answers 'n behalf of the permittees and that in o & r to answer the foregoing interrogatories he has caused inquiry to be made of the appropriate persons and that the answers, to the best of his knowledge, represent in each case such information as is available to the permittees and are, to the best of his knowledge, true. Before me, Notary Publ* ff ~ My Cor.r.is _on Expires: THOUAS 0. C: . .. :4, ,:. L t;GTAr,Y :imuc M/ c:a.m. cSires Feb. 9,1991 l l l l

                 $     $-{ %           l'            .;l~Q                 .f.l,.'ll

_ 5f [."j$ :j Z^ & g __ - =2 .-_ . .

                                                                                                                - -- 4                                        c S$*E'~ih W,                                                     -k                                                                            -

of. 7

                                                                                                                              .k
       #$                                                                                                                     4                                   l
                                                                                                                                ;                           sE:

l ' 762 MICHAEL A. CHINNERY .-. 2 accumulated in both the Southern New England region and the Boston New Hampshire zone for the period 1800 to 1959. These are listed in Tables 3 and 4, respectively. As before, small events are only accumulated for the most recent b portion of the record. ..; The cumulative frequency intensity plot for Southern New England is shown in o

     !                                                                                                                                                     o c f                      Figure 6. The straight line through the data has the form                                           $
                                                                                                                               !.i             o Log N, - 2.36 - 0.591.                                (4)    '.

l In spite of the rather low numbers of events, this line is a reasonable fit to the data.

                                                                                                                                       /

O l In the case of the Boston-New Hampshire zone, however, the number of events .: M- o oD W i to MISSISS;PPI VALLEY k ' ". " ' ' " 1840 -1969 js , o.5 - 3

                                                                                                                                 ~                            c 4q         -

Nw i or . i, 4'.' e

3 _-

3>- ,

          ,                                      e - 0. 5    -                                                                                   ,
                                                 $                                                                                 i
                                                                                                                                          )f   '

u ,

          .,                                     z p       ** W o    -10'~                                                                                             (ka a-d                                   .J r         1 O

hq ,

                                                                                                                                                   \o l
                                                       ~
                                                              ~ Log N =  c 2.77-0.551 N
   >ty
   ,- i .                                                                                                                           :
       *                                               -ro    -                                                                                           .
                                                                                                                                               =o.

2 2 22 I 2[ NTENSITY Fic. 4. Cumulative frequency. intensity plot for the data in Table 2. I j be i .-

    '!(                                                                                                                                     .W\
  • becomes low enough that it becomes difficult to formulate a linear fit ith any certainty. A straight line through the upper four data points has a shallow slope Fic. 5. E southern.s '

f[. (about 0.50), which is significantly different from the other areas studied, and which leads to high estimates of risk for large events. We prefer to interpret these data

     ;s                      with a line such as the one shown, which has the equation l

h, log N, = 2.15 - 0.591. (5) The fre M in Figure

     *4  .                    With this interpretation, the number of intensity VII earthquakes is anomalously                              straight h D                       high, due either to poor data or a statistical fluctuation. At least equation (5) should                      of the fot lead to reasonably conservative estimates for risk at high intensity levels.

{ F I G.1

                                /

10.0 _ i , i i i i i i i i i

                                                                                                      ]

O o MISSISSIPPI VALLEY - e 1.0 - x 4 y Log Ne = 2.77-0.55I x W A

a. o,i _ -

x - g _ _ 3 _ z _ _ W A 2 3 D _ - J D A A A O 2 o

               .01 :

A RECURRENCE DATA FROM

                     ~

TABLE 2; CHINNERY (1979) - _ PLUS NEW MADRID EVENTS _ _ 0F 1811- 18I2; MMI=X-Xil

  • 0 RECURRENCE DATA FROM

_ TABLE 2; CHINNERY(1979) -

   ,                      MISSISSIPPI VALLEY

_ 1840-1969 -

            .0 01 l     ll       111  IV   V      VI     Vil   Vill IX       X     XI   XII INTENSITY Fi G. 2 l

CERTIFICATE OF SERVICE I, Thomas G. Dignan, Jr., one of the attorneys for the applicants herein, hereby certify that on January 21, 1931, I made service of the within dccument by mailing copies thereof, postage prepaid, first class or airmail, to: Alan S. Rosenthal, Chairman Ellyn R. Weiss, Esquire Atomic Safety and Licensing Harmon & Weiss Appeal Board Suite 506 U.S. Nuclear Regulatory Commission 1725 7 Street, N.W. Washington,~.D.C. 20555 Wasbington, D.C. 20006 Dr John H. Buck Robert A. Backus, Esquire

        !. comic Safety and Licensing          O'Neill Backus Spielman Appeal Board u.S. Nuclear Regulatory Commission     116 Lowell Street Washington, D.C. 20555                 Manchester, New Hampshire   03105 Dr. W. Reed Johnson Stuart K. Becker, Esquire Atomic Safety and Licensing Maxine I. Lipeles, Esquire Appeal Board                        Assistant Attorneys General U.S. Nuclear Regulatory Commission     Environmental Protection Division Washington, D.C. 20555                 Department of the Attorney General One Ashburton Place, 19th Floor Boston, Massachusetts   02108 Ms. Elizabeth H. Weinhold 3 Godfrey Avenue                       Roy P. Lessy, Jr., Esquire              ;

Hampton, New Hampshire 03842 j Office of the Executive Legal  ; Director j. Atomic Safety and Licensing U.S. Nuclear Regulatory Commission i Board Panel Washington, D.C. 20555 i U.S. Nuclear Rer;1atory Commission ' Washington, D.C. 20555 Office of the Attorney General  : 208 State House Annex } Concord, New Hampshire 03301  ; t Thomas G. Dignan, Jr.  ; Thomas G. Dignan, Jr. p4 t

                                                                                  ,}}