ML20236B012
| ML20236B012 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon, 05000000 |
| Issue date: | 08/24/1977 |
| From: | Stolz J Office of Nuclear Reactor Regulation |
| To: | Morrissey J PACIFIC GAS & ELECTRIC CO. |
| Shared Package | |
| ML20236A877 | List:
|
| References | |
| FOIA-87-214 NUDOCS 8707280303 | |
| Download: ML20236B012 (14) | |
Text
._
i 4
Distribstio.
Docket Fil W. P. Gammill H. Levin]
NRC PDR, ELD.
]
]
AUG 21 1977 n.R 1 File LW I. Sihweil S. Boyd D. Jeng R. C. DeYoung A. Fratoni l
D. B. Vassallo P. T;Brien Kuo Docket No. 50-275 F. J. A liams J. O and 50-323 i
J. Stolz R. Bosnak D. Allison P. Y. Chen
)
E. Hylte E. Sullivan
]
Pactfic Gas and Electric Company R. J j b
-PP ATTN Mr. John C. Morrissey
,Rb Vice President & General Counsel J. Knight ~
N. Newmark', U. of Ill.
[ [*d U?'o San c sc California 94106
~
n n n
I V. A.j' Moore T. Hirons R. He Vollmer J. Wetmore l
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATlhN.: drfMf0,CANYONh0CTfRR L
POWER PLANT, UNITS 1 AND 2 l
We are reviewing the information regarding seismic reevaluat.fon that
</
you submitted in Amendment 50 to the Final *$dfet'j Analysis Report (FSAR).
As a result of our review we find that additional information is required to complete our review. The additional informati n required is described 9
in the enclosure.
Our review of Amendment 50 is continuing and we expect to. request further infonnation in the near future.
l 1
Please inform us of your schedule for submitting the information requested i
in the enclosure and contact us if you have any questions.
Sincerely, Originni signed by[
.lohn F,. Stolz j
John F. Stolz. Chief Light Water Reactors Branch No. 1 Division of Project Management 1
Enclosure:
Request for Additional Information bcc:
J. R. Buchanan, MSIC cc w/ enclosure: See Page 2 T. B. Abernathy, TIC ACRS (16)
I I
0 A.3
,,b 1
b
_1, orrics >
DAllisb/ rec
_JS
.Nl.f.??
..kl
.? ?....
l-o Ase >
NRCFoRM 318 (9 76) NRCM 0240 W va s. oOVERNMENT PRINTING OrFICEs 1978== S26-484 B707280303 870721 n
1 o,
I l
Pacific Cas & Electric Company A U e. " ' 1977 cc Philip A. Crane, Jr., Esq.
Ms. Elizabeth E. Apfelberg Pacific Gas and Electric Company 1415 Cazadero 77 Beale Street San Luis Cbispo, California 93401 ~
San Francisco, California 94106 Mr. William P. Cornwell
{
Janice E. Kerr, Esq.
P. O. Box 453 i
California Public Utilities Comission Morro Bay, California 93442 350 McAllister Street San Francisco, California 94102 hr. James O. Schuyler, Nuclear Project Ergineer Mr. Frederick Eissler, President
/ Pacific Gas & Electric Oxnpany I
i Scenic Shoreline Preservation
/ 77 Beale Street i
Conference, Inc.
e San Francisco, California 94106 4623 More Mesa Drive Santa Barbara, California 93105 David F. Fleischaker, Esq.
l 102515th Street, N. W.
l Ms. Sandra A. Silver Washington, D. C.
20005 Mr. Cbrdon A. Silver l
425 Luneta Drive Mr. W. C. Gangloff San Luis Obispo, California 94301 Westinghouse Electric Corporation l
P. O. Box 355 I
l Brent Rushforth, Esq.
Pittsburgh, Pennsylvania 15230 Center for Law in the Public Interest 10203 Santa *>nica Boulevarc Yale I. Jones, Esq.
Los Angeles, California 90067 100 Van Ness Avenue l
19th Floor Paul C. Valentine, Esq.
San Francisco, California 94102 400 Cnanning Avenue Palto Alto, California 94301 Bruce Norton, Esq.
3216 North 3rd Street Ms. Raye Fle:ning Suite 202 1746 Charro Street Phoenix, Arizona 85012 San Luia Golspo, Caliiornia 93401 Arthur C. Gehr, Esq.
Neil Goldoerg, Esq.
Snell & Wilmer Wilmer, Cutler & Pickering 3100 Valley Center 1666 K Street, N. W.
Phoenix, Arizona 85012 Washington, D. C.
20006 l
1 i
l c rric s >
i sWRNAles %
D'M >
NRC FORM 318 (9 74) NRCM 0240 W u. s. sovsan.asNT raiarano orr#cre ee7e eas.ea4
.__-_-________-_____._w
ENCLOSURE j
1 REQUEST FOR ADDITIONAL INFORMATION 1
PACIFIC GAS AND ELECTRIC COMPANY l
1 l
DIABLO CANYON, UNITS 1 AND 2 DOCKET NUMBERS 50-275,AND 50f-323 l
/
i i
l 1
i i
4,
3.0 DESIG!! CRITERIA - STPsVCTURES, COMPO.NEilTS, EQUIPMENT AND SYSTEMS 3.54 On page 2-6, Par. 1, two statements are made that "this combination was obtained by summing the vertical and the most critical horizontal loads within each mode. These summed horizontal.
. by the square root sum of the squares (SRSS) method." Since the natural frequencies and mode shapes of the structures are not the same in separate horizontal and vertical directions, the responses resulting from l
these analyses should not be combined on a modal basis.
Indicate if this same technique was used in the re-an#' lysis.
If so, justification s
should be provided.
3.55 on page 2-7, Par. 2, the statement is made that "for non-linear analysis that considers gaps between supports, impact damping is also considered."
Define the term " impact damping," provide the! value assigned thereto, and the method of its use and justification therefor.
3.56 On page 2-10, it is stated that a component or piping was considered to be rigid if the natural period was less than 0.05 seconds (2.2.3.3) and 0.066 seconds (2.2.3.5).
Indicate if the same criteria were used in the reevaluation.
If so, please provide justifications.
It is normally the staf f's position that a comp 6nent or equipment is considered rigid if its natural frequency is equal to or above 33 cps.
3.57 on pages 2-11, and 2-15, a seismic acceleration of "2g" is quoted as the upper bound used for certain piping systems.
Indicate if the same criterion was used in the reevaluation.
If so, justification should be provided since some in-structure response spectra may have spectral accelerations higher than 2g..
3.58 Define the term " State vector" used in Page 2-16 and other places.
' 3.59 On page 3-10, last paragraph, the statement is made:
"....the probability of exceeding the.75 g effective ground acceleration in 50 years is 0.1% or an average return period of 52,600 years...."
Although these values are consistent, the statement is not worded clearly and is subject to misinterpretation.
Please clarify.
3.60 On page 4-3, last paragraph, the. statement is made that, in the DDE analyses, theverticalresponseandoneho[izontalresponsewere
/
combined on an absolute sum basis.
This/is inconsistent with the statements on page 2-6 (see Question 1).
Please clarify.
3.61 With ref erence to Vol.1, p. 4-3, par.,5, torsional ef fects due to wave propagation appear to have been considered. However, no reference is made to ways in which tilting or. tipping. effects from wave propagation were cons'idered.
Please explain the basis for neglecting these ef fects, or indicate how you plan to consider them.
3.62 On page 4-3, par. 5, the statement is made that "this eccentricity was either 5%....or... 7%....
with the transnational results, which-l ever was greater."
This statement does not indicate how the response due to 5% additional eccentricity was combined with the transnational results.
Please clarify.
3.63 On page 4-5, par. 3, the statement that "this is in accordance with....
greater than 3000 fps"is incorrect.
The number 3000 fps should be 3500 fps in accordance w,ith Section 3.7 of the SRP.
3.64 Item 6 on Page 4-6 states that " accidental totsion is included by
.........., or an equivalent arount for buildings without rigid
, floor diaphragms".
Please specify what constitutes "an equivalent amount" I
and what constitutes a " rigid floor diaphragm" and provide justifi-l I
cations.
3.65 On page 4-6, last paragraph, the statement is made that "the inelastic response to the Hosgri motions.... do not exceed 3 on a story basis....
shear walls are limited to 1.3 and to 6 in reinforcing steel." Explain how a ductility value is determined for a ptory frame which is J
composed of beams, columns, and bracing.
Also explain how the ductility l
l values of 1.3 for shear walls and 6 for reinforcing steel were used l
l in the analysis.
3.66 On page
-7, par.2, the statement is made thit "in generating the floor response spectra for...'. elastic and inelastic using.... of material 1
s t'r'e ng th. " Explain how floor response sp'ectra were generated by-means of an inelastic analysis of the building.
3.67 On page 4-10 Paragraph 4.2.1.1, clarify:
1 I
(a) How the stiffnesses of the elemests in the F.E.M. analysis reflectedthecombinedpropbrtiesofconcreteandsteel?
If the properties of the reinforcing steel were neglected:
(1) how would the analysis for concrete cracking be performed?
(ii) discontinuities in forces at places of rebar termination could not be obtained (i.e.at El. 170'-172').
If the properties of the reinforcing steel were considered:
l l
(1) Would the elements be orthotropic?
l l
(b) How were the properties in the F.E.M. analysis formulated to account for the embedded steel sections at the bottom 20' of the
cylinder considering the slip surface due to the asbestos used at the face of the beam?
(c) How does the fixed model as shown in Figs. 4-24 and 4-26 take account of the pin connection at the containment base?
3.67 On page 4-9, Section 4.2.1, please clarify the following:
'(a)
By including the 5% (or 7%) equivalent, eccentricity in the math-ematicalmodel,theresultingfreque[ciesandmodeshapesfor a coupled motion will be changed to those which no longer represent j
the physical characteristic of the containment.
The definition of H and H n Page 4-11 appears to be misleading.
H is g
T05 g
not the horizontal response due to horizontal ground motion.
Rather, H is a horizontal component and HT05 "
- component of a coupled motion due'to a horizontal input.
In this method of analysis, H and H cann t e separated.
g TOS (b) How would the comparison be if the forces and moments were com-puted by summing up:
(i) responses using uncoupl,ed horizontal mode shapes and frequencies, and (ii) responses due to torsional moment which is the product of the equivalent eccentricity and the inertia forces from (i) above.
(c)
For responses combined on an absolute sum basis, Equation (1) on Page 4-11 should be revised to read:
H =lHgl+lX*H T
TOR (d)
How were the torsional stiffnesses in the coupled analysis c*omputed?
1
, 3 1
l (e) On page 4-11, H was defined as the torsional response at the T05 center line of the containment.
In Fig. 4-26, the coordinate q
I axes were defined at each mass point.
Clarify how the difference between these definitions was accounted' f or in the analysis.
3.68 On page 4-12, par.4, the statement is made that " vertical acceleration and displacement responses-------of the same,axisymmetric model".
1
(
Provide a comparison of results obtained b7thetwodifferenttechniques,
.o
\\
namely, response spectrum analysis and time history modal superposition l
l 1
I analysis.
1 j
3.69 On Page 4-13 Section 4.2.1.2, clarify what were the criteria used in constructing the equivalent axisymmetric model and how was the axi-symmetric finite element model modified to analyze the shear walls wasymmetric about the' structural axis?
3.70 Fig. 4-20 shows that the idealized center line of the containment and its interior structures does not coincide with that of the reactor vessel.
Clarify how this effect is ac, counted for in the axisymmetric model.
4 3.71 Provide justifications for neglecting walls above El.140' in the mathematical model for the interior structure.
3.72 Fig. 9 cited on Page 4-18, par.3 is not included. Please provide.
3.73 On Page 4-13, Par.4, the statement is made that "Model 1 in---- to the applied loads." Since the model is a coupled model which includes both geometric and 5% equivalent eccentricities, the contribution from the equivalent eccentricity cannot he separated f rom that of the 1
geometric eccentricity.
Clarify how the ABS (or SRSS) of the response due to 5% (7%) eccentricity and the remaining responses were combined.
i 3.74 The mathematical model used for vertical analysis of the interior l
l structure as shown in Fig. 4-28 does not appear to properly represent
~
l the physical characteristics of the structure.
Clarification is required.
f 3.75 On page 4-15, the last paragraph refers to/ the combination of effects 4
due to horizontal input motions.
It is not clear that in all cases the horizontal motion effects are due entirely to one direction of motion.
For example, the maximum vertical stress due to motion in 7
I l
one direction may occur at the same time as the maximum shear due i
to motion at right angles to that direction.
Please explain.
3.76 On p. 4-16, par.1, the statement is made that "the horizontal inputs do not produce a not axial force." But they do produce local axial forces.
Similarly, the vertical motion may produce local shearing forces, as for example in the dome. Were these taken into account?
Under what conditions does "the t,hree component SRSS.. combination (beceme) equal to /2" times the response due to horizontal input"?
l 3.77 On Page 4-16, Par.2, the statement is made that "in specific situations, i
a reduction....cannot be reduced." The staff position has been that in using Newmark Spectra, the reduction due to ductility consideration 1
is not permitted.
Delete the words "in general" or clarify your intention.
1 3.78 Equation (5) on Page 4-16 should be revised as fellows:
(
l l
l 6
L-_.._--____-_---_____._____._____.-__
1 7_
g*A E
- bCL
- bCL'
+
H Table lla cited on Page 4-17 is not included and should be provided.
3.79 On page 4-18, Par.5, the statements are made,that " maximum stresses due to combination of LOCA---decreasing to 60 Ks1 within a short distance."
Identify which of the New ark or Blume Hosgri spectrum was used.
If 1
the Blume Hosgri spectra were used, what would be the ductility value f
corresponding to the results?
/
o 3.80 With reference to the evaluation of the 200 Ton Polar Gantry Crane on Pages 4-18 and 19, clarify the following:
(a) What was the input used in the analysis?
(b) What was the boundary condit1ons of the ' mathematical model shown in Fig. 4-297 (c) What were the natural frequencies of the crane system?
l 3.81 On Page 4-20, Par. 4, the statement is made that "The combined transla-tional and torsional spectra---- shown in Figs. 4-30 to 4-47."
Clarify how this was done with a mathematical <nodel as shown in Fig. 4-24.
J.
4 1
3.82 Clarify if there is any difference between Equations (1) on page 4-11 and (5) on Page 4-16.
3.83 How was the floor response of the auxiliary building at El.125'-0 computed? The model, Fig. 4-108, did not show a mass point at this elevation.
3.84 Fig. 4-108 shows the base of the model at El. 85'-0. Clarify how was the response of the structure below El. 85'0 computed?
In addition
justify why the input motion was not at the foundation mat elevation.
3.85 On Page 4-26, Par.1, the statements are made that "the interaction l
l between the structure and the upward-sloping grade......on the east side of the building." It is our understanding that the soil springs l
were used to account for the effect of embedment, since the model 1
shown in Fig. 4-108 was fixed at El. 85'-0.
,Pr; vide justification for the use of the elastic half-space theory in deriving the spring stiff-
/
/
nesses.
3.86 Da Page 4-26, Par.3, the statement is made that " locations of the centers of mass....of vibration in the analysis." In order to accomplish this, the location and mass of each and every piece of equipment must already be known.
Explain why a 100 psf load had to be used in the ' computation of ' lateral masses to account for these
~
equipment.
l l
3.87 The mathematical codel shown in Fig. 4-108 includes both geometric i
eccentricities and the 5% (or 7%) acci; dental eccentricities.
Clarify how in computing f requencies and ' mode shapes and in ecmbining the transnational and torsional responses, the ef f ects of the two types of eccentricities were separated.
Clarify and justify if the consideration i
given to the effects of these eccentricities as described in Section 4.3.1.1 on Pages 4-27 and 4-28 was adequate.
3.88 It is indicated on Page 4-34, Par. I that the detailed review of critical shear walls considered the effects of embedded columns,
" flange" effect of perpendicular walls, and variable wall thickness.
E'aborate on the method used for the analycis of these effects.
l 9.-
)
l l
3.89 The details of the fuel-handling crane support structure referred to
)
on p. 4-36 are not included.
Please provide.
3.90 On Page 4-37, Par.6, the statement is made that "For a north-south input.......according to Equation (4)." It is not clear which Equation (4) was referred to.
Please clarify.
l l
3.91 With reference to Sections 4.4.5 and 4.4.6 on' Pages 4-43 and 4-44, i
i please indicate if there was any analysis performed after the modifi-cations.
If so, what were the resulting' stresses and/or deformations?
Elaborate on whether an elastic and inelastic analysis was employed
)
in the computation.
3.92 Figs. 4-308 and 4-309 used as seismic input f'r the analysis of the o
intake structure appear to correspond 'to the longer dimension of the,
intake structure.
Justify the use of these spectra for the analysis in the shorter dimension.
l l
3.93 On Pages 4-48 and 50, referring to the intake structure, what conservatism, if any, is involved in the increase of response in j
each horizontal earthquake input by a factor of 1.10, rather than using a value of eccentricity of 5% of the width.
3.94 On Page 4-49, Par.1, the statement is made that "three three-dimensional mathematical models... in the corresponding direction." If a three-dimensional model was properly developed, it could be used for analyses in"all directions.
Explain why three three-dimensional models were used for the analysis of the intake structure. Also, the description in the second paragraph of the same page does not L---______ _ _
appear to be that of a three dimensional model.
Justifications are required.
3.95 In the analysis of the intake structure, was the hydrodynamic I
effect of water considered? In the computation of total shear stresses I
snd bending moments, were the effects of hydrostatic and earth pressure l
l included? Please clarify.
1
/
3.96 on Pages 4-51 and 4-52 the piers in the iptake structure in the i
li-S direction are overstressed in flexure under the elastic analysis by an amount one-third greater than their calculated ultimate moment capacity.
Discuss how this moment was calculated and provide key calculations. What does this mean with regard to amount of inelastic I
deformation, or ductility f actor required to be mobilized? Will l
any remedy action be taken? Will'the screen wall maintain its integrity or will it collapse? Please elaborate.
t 3.97 Tabie 4-8 shows vertical displacements due to both horizontal seismic
)
inputs and vertical inputs.
Explain how you obtain verticci displace-ments due to horizontal inputs in an axisymmetric structure on a fixed base.
In addition explain why the disp]neements are less near the crown of the dome than further down at the cylindrical section of the containment building.
3.98 In addition to the shears included in Table 4-11, provide the shear l
l forces in the-dome'shell due to the vertical input.
In what directions l
l are the shears in the shell computed and how are they combined with the net shear forces on the wall.
I 1
.)
. l l
3.99 Provide descriptions and validation procedures for all the computer programs used in the analyses.
I I
)
i i
e
/
j i
l i
P t
I
hb J
w i
JUL 2 81977 l
Docket Nos. 50-275 and 50-323 NOTE TO: John F. Stolz, Chief, Light Water Reactors Branch No.1 DPkt 1
I FROM:
Dennis P. Allison. Project Manager, Light Water Reactors Branch No.1, DPM
/
SUBJECT:
DIABLO CANYON SEISMIC DESIGN - ACRS/ CONSULTANT C0t9 TENTS The attached connents have been received from ACRS consultants concerning Diablo Canyon.
Original Signed By Dennis P. Allison Dennis P. Allison Project Manaper Light Water Reactors Branch fio. 1 Division of Project Management cc:
See page 2 l
Distribution NRC PDil L. Shao 2
Local PDR H. Levin N. Gammill J. Netnore 1
J. C. Stepp
- 4. Newmark, Univ.$ of Ill.
R. Hoffmann W. Hall, Uni,v. of Ill.
J. Knight J. Devine, USGS Reston
- 1. Sihweil E. Case D. Jeng H. Denton R. Bosnak D. Muller E. Sullivan R. Royd P. Y. Chen R. Mattson J. O'Brien F. Schroeder R. C. DeYoung D. B. Vassallo J. Stolz D. Allison
%/,' (j J. Tourtellotte, ELD I
YM i
L. D. Davis, ELD I
R. Goddard, ELD l
LWML orn a *.
i DA111sco
.u...
l
\\..,.
- 7/h/77 l
meroa sur.m amom
- w.........,..-,....,u.
yt (i eeon 532<3 yg.
-c-JUL 2 61977 oc:
Pacific Gas and Electric Company Mr. William P. Cornwell ATTN:
Mr. John C. Morrissey P. O. Box 453 Vice President & General Morro Bay, California 93442 Counsel 77 Beale Street Mr. James 0. Schuyler, Nuclear San Francisco, California 94106 Projects Engineer Pacific Gas and Electric Comnany Philip A. Crane, Jr., Esq.
77 Beale Street Pacific Gas and Electric Company San Francisco, California 9d106 77 Beale Street San Francisco, California 94106 Mr. W. C. Gangloff Westinghouse Electric Corocration i
l Janice E. Kerr, Esq.
P. O. Box 355 California Public Utilities Pittsburgh., Pennsylvania 15230 Commission 350 McAllister Street Brent Rushforth, Esq.
l San Francisco, California 94102 Center for Law in the Public Interest 10203 fanta Monica Boulevard j
Mr. Frederick Eissler, President Los An'geles, California 90067 1
Scenic Shoreline Preservation l
Conference, Inc.
Arthur C. Gehr, Esq.
i 4623 More Mesa Drive Snell & Wilmer l
l Santa Barbara, California 93105 3100 Valley r nter e
Phoenix, Arizona 85073 Ms. Elizabeth E. Apfelberg 1415 Cazadero Bruce Norton, Esq.
San Luis Obispo, California 93401 3216 North 3rd Street Suite 202 Ms. Sandra A. Silver Phoenix, Arizona 85012 425 Luneta Drive San Luis Obispo, California 93401 Neil Goldberg, Esq.
Wilmer, Cutler & Pickering Mr. Gordon A. Silver 1666 K Street, N. W.
425 Luneta Drive Washington, D. C.
20006 San Luis Obispo, California 93401 David F. Fleischaker, Esn.
Paul C. Valentine, Esq.
1025 15th Street, N. W.
l
)
400 Channing Avenue 5th Floor l
Palo Alto, California 94301 Washington, D. C.
20005 Yale 1. Jones, Esq.
Mr. Paul Morton 100 Van Ness Avenue California Division of Mines and 19th Floor Geology San Francisco, California 94102 28 Civic Center Plaza Room 642 Ms. Raye Fleming Sar.ta Ana, California 92701 1746 Chorro Street San Luis Obispo, California 93401 i
Ann Arbor, Michigan 48109 r.:.. :
((,
/4/
June 28, 1977 J 49 j', ;
4..
Mr. John C. McKinley - ACRS Nuclear Regulatory Commission
- '.,y y j ;
,. U ;Bi Washington, DC 20555 S
D?ar Mr. McKinley:
I am writing to give you my impressions of the Diablo sub-committee meeting held in Los Angeles on June 21-23, 1977 The considerable discussion of the various statistical approaches did not lea.' to a resolution of the differing conclu-sions although I think they are related to the'different choices of seismicity and spectral attenuation.
In any case, it became clear that probabilistic approaches would n A fully answer our questions for this site.
Increasi ngly, I think evidence is accumulating that a mag-nitude 7} or. the Hosgri fault may be too large.
This is, of ccatrs e, scmewhat moot as the expected accelerations may well top out at magnitude 6 3/4 or.less.
1 1
I still think the nature of the Hosgri fault -- its expected stress drop and type of slip.-- is controlling! for the maximum acceleration and that its expected seismicity -- less than the San Andrc as ? -- controls the probability.
Evidence is accumulating for C.75 g as an appropriate anchor point for the Diablo spectrum.
However, questions still remain, I
particularly.with regard to the applicant's use of 7% damping and a 'b factor for the larger structures l
Professor Brune raised valid questions regarding focussing l
near the f.. ult; however, these effects will be minimized at high frequencies (greater than 2 Hz) and in my opinion, argue more for the choice of a truly conservative anchor point from existing data than for markedly increasing such an' anchor point.
Very truly yours, s
4 WM h
JTW/md OS QD&3 I
w G E O R G E ' A. T H O M P S O,N d21 Adobe Place l
Palo Alto, California 94306 Q..-
l
( Y ' 0$$-
l 0 - SunEI 5,lt977 2
h I
l U.S, !q.t.
Diablo Canyon Subcothmit' tee 40ViSt.W ;.
"d f y c
. y, RIACICR5c,,20g,(Q3 JUNE 21-23 MEETING, LOS ANGELES I
Use of an effn7 ive acceleration of 0 75 6 for an l
t earthquake of M 7 5 was discussed at length.
The con-4 ve'rgence of empirical and theoretical approaches by both Newmark and Blume brought this matter t4 resolution or very nearly so.
Residual questions abdut Tau (filtering effect for large foundations) and damping will undoubtedly be addressed by those more expert on these questions than I am.
The probabilities of aite accelerations vere treated by Blume, Smith and Ccrnell.
By excluding tne San Andreas fault and the 1927 Lompoc earthquake they,obtained pro-babilities at least two orders of magnitude smaller than those of Trifunac.
I had commented earlier in a letter to ACRS that it is not proper to include the San Andreas, because the largest geologic estimates of slip rate on the Hosgri zone are an order of maenitude'less than on the San Andreas.
A manuscript on the location of the 1927 earth-quake by Thomas Hanks of the USGS became available at the meeting.
Strong evidence is offered far a southern,loca-tion of this earthquake off the Hosgri zone.
I would add that large offsets of the ocea.; bottom and. Holocene sefi-ments are shown in the reflection seismic sections only in the southern region (opposito the Transverse Ranges).
These lines of evidence are all relevant to the Blume pro-bability calculation and, moreover, suggest that the origi-nal assumption of M 7 5 earthquakes on the Hosgri was over-conservative.
An additional line of reasoning may yield further evi-(1) What is the historical slip rate in the vicinity dence of the Hosgri zone from seismic moments in the lest 50 years?
(2) What is the Holocene (17,000 year) rate on the Hosgri from the largest permissible offsets on seismic reflection sections and coastal terraces?
(3) How do these rates com-pare with the divergent estimates of the 15 million year rate?
My impression is that the postulated 80 km offset.
if correct, occurred at a decreasing rate.
A low rate in later geologic time would explain the discontinuous strands of the Hongri fault, which are unliko large, presently active strike slip faults.
\\
\\
ygac no70/
\\
a pg.
p y
s
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _. _ - - - - - - - - - - - - - - - - - - - - - - - - - ' - - - - - - - ~ ~ - - - - - ^ - -
Robert Curry's argument that "The Hosgri must be treated like the San Andreas" was gently demolished by_
l Dr. Page's demonstration of how different the, slip rates must be.
Curry also referred to allan Lindh's study of
. California seismicity to infer that earthquake activity h
alternated between the San Andreas and offshore faults.
Lindh made no such general inference, and I have sent the relevant chapter of his thesis ( a rough draft, without his pe2 mission) to record that fact. '
I l
James Brune gave a well balanced discussion of focus-l sing of energy due to rupture propagation along faults.
Computational models show-the phenomenon clearly.
Brune himself noted that inhomogeneities would? 1.essen the effect, and Stepp noted that the earth is notoriously inhomoge-neous.
Moreover, despite the rare. instrumental racerd.7 j
that might reflect focussing (as Gazli, Russia), the much.
more complete evidence-from damage do'es not support the i* dea, at least as an engineering concern.- We simply do not see na' row zones of great damage along fenits.
If r
this topic is to be explored further'for Diablo Canyon,,
.the main question to be asked ist Can focussing effects
.be demonstrated or eliminated by damage (intensi ty) data?
I conclude that we have moved a longtway toward reso-lution of seismic problems at Diablo Canyon.
U4 I 9
i l
9 e
a C
JUL 11 1977 Docket Nos. 50-275 and 50-323 NEMORANDUM FOR: John F. Stolz, Chief. Light Water Reactors Branch No.1 FROM:
Dennis Allison, Project Manager, Light Water Reactors Branch No. 1 SUBJECT DIABLOCANYONSEISMICDESIGN-/FREEDOMOFINFORMATION (FOIA) REQUEST - FOIA-77-48 The purpose of this memorandum is to make available five documents that were released on June 30,1977 to be included in the public record of Congressional Hearings concerning Diablo Canyon.
In the NRC's response to the subject FOIA request, the five enclosed documents (along with six others) were withhsid.
Regarding some of the documents, the matter was appealed to Mr. Gossick; who upheld the previous decision.
However, on June 30, 1977, in response to a specific request contained in a letter dated June 27, 1977 from Representative Udall, the five attached documents were released. They were included in the public record of hearirigs held on that day by the House Subcommittee on Energy and the Environment.
Original Signed By Dennis P. Allison Dennis P. Allison, Project Manager Light Water Reactors Branch No. I
~
Di, vision of Project Management
Enclosures:
1.
November 24, 1976 Memo for H. R. Denton from R. B. Hofmann, Subj: Recommendations Concerning Possible Courses of Action Regarding Diablo Canyon 2
March 8, 1977 Memo for Benard C. Rusche from John O'Brien, Subj Proposed Interim License for Diablo Canyon (SEB:IIII) 3.
March 9,1977 Hemo for W. P. Gamm111 from
/f/ )/83 J. Carl Stepp, Subj: Diablo Canyon Licensing Option 1
L orrie s >
~-
eunuaus >
bb x
Ai NRC PORMals (9 76) NRCM 0240 W us s. oovanNurwT mNTING OFFICEe 107e = ese.ead gea a so 201 i) q
i O
i e
i c
2 John F. Stolz,JUl.1c M77 Enclosures Con't:
4.
Undated Draft. Highlights of PG&E Diablo Canyon Plant Seismic Design Audit 5.
December 29, 1976 Memo for D. A111sor, from J.
C'. Stapp, Subj: Response to ACRS Consultants Recensendations Regarding the Diablo Canyon Review ces w/ enclosures:
Brant Rushforth, Esquire - CLPI Malcolm Furbush, Esquire, Pacific Gas & Electric e
Company
/
L. Dow Davis, Esquire - NRC j
PDR - FOIA-77-48 File
' distribution w/o ;ncis PDR - 50/275 & 50/323 File Docket Files V LPDR - F01A-77-48 File ORR Rda LPDR - 50/275 & 50/323 File DRR Subj GErtter LVGossick WJDircks REGtRdg DJDonoghue JMavnard DDambly JFouchard RJBrady SEilperin BNorton JHoyle Accession Unit JCSten.o JMrien D.Hoffmann DAllison w/ enclosure JLonn (with original enclosures) l I
oP' 8CE P DAl__1 i fon/_ rec
.u,,,,,,.
7/ll/,77 o.v.,
j NRC PORM 318 (976) NRCM 0240 W va s.oovsanuawr ensurine orricas teve -ese4a4
_