ML20050B781

Submits Final Review Re Geological Aspects of Site as Presented in Fsar,Chapter 2.5.Data Sufficient to Provide Basis for Reasonable Assurance That Faults Are Not Capable

ML20050B781
Person / Time
Site:	Perry
Issue date:	03/10/1982
From:	Devine J INTERIOR, DEPT. OF, GEOLOGICAL SURVEY
To:	Rolonda Jackson Office of Nuclear Reactor Regulation
References
NUDOCS 8204070404
Download: ML20050B781 (6)

Text

-

s. .

p United States Department of the Interior GEOLOGICAL SURVEY RESTON, VA. 22092 N f &)

In Reply Refer To:

ECS-Mail Stop 908 March 10, 1982 g gh-g, ,

3 %'o%go

> 2 N ,

Robert E. Jackson 6 U.S. Nuclear Regulatory Commission \

Of fice of Nuclear Reactor Regulation #

to ,*

Washington, D.C. 20555

Dear Bob:

Enclosed is the Final Review for the Ferry Nuclear Power Plant, Perry, Ohio, docket nos. 50-440 and 50-441. Although the applicant was not able, under the restricting condition of sub-lake tunnel boring, to demonstrate conclusively that the tunnel faults are not capable, the data provided are sufficient that prudent use of scientific judgment and cognizance of the present stress regime provides the basis for reatonable assurance that the faults are not capable.

The review was prepared by M. T. Hait, Jr. and H. S. Swolfs.

Sincerely, f

smnd gamesF.Devine Assistant Director - for Engineering Enclosure Qool s

/

/)no'-

&,{

9, Sc.he'/

G204070404 820310 PDR ADOCK 05000440 A pyg

Final Review Perry, Ohio M. H. Hait, Jr.

H. S. Swolf s March 8, 1982 i Cleveland Electric Illuminating Company Perry Nuclear Power Plant, Units 1 and 2 Lake County, Ohio NRC Docket Nos. 50-440 and 50-441 Comments We have reviewed the geological aspects of the Perry Site as presented in Chapter 2.5 of the FSAR and Appendices, and the responses ,

to NRC questions 231.3 and 231.4. The questione are covered by a July 28, 1981, memo from Jackson (DE/NRC) to Schwencer (DL/NRC); the responses are in a document covered by an October 30, 1981, letter from Davidson (Cleveland Electric Illuminating Company) to Tedasco (DL/NRC) . Our review is based on information supplied by the applicant and the U.S. Geological Survey has not conducted any original investigations pertinent to the Perry Site. The principal concern centered on the thrust faults discovered in the intake and discharge tunnels.

The applicants responses present reasonable summaries of the various data on the tunnel f aults. Thrust f aults identified in the tunnels were investigated by the applicant, however, the age of last movement was not unambiguously determined. According to the applicant, the fault gouge consolidation tests gave an. age possibly younge.r than that of the unbroken crystals in microcracks = in the f ault. plane.

However, the applicant's analysis that movement on these f aults in the 1

4.

present stress regime is highly unlikely appears to be reasonable. This analysis shows the present principal stress to be aligned perpendiculer to the stress which caused the original. faulting. The applicant's analysis to determine the present stress regime used two dif ferent kinds of data: (1) regional data cited in the literature and (2)

I hydrofracturing tests. These data are conformable, therefore, the present stress regime seems to be adequately defined.

Our evaluation of the applicants analysis of the possibility of faulting being initiated in the present stress regime is summarized in Figures 1 and 2. It shows that existing stresses required for thrust movement (in the plane narmal to the fault) are lower by a factor of about 2.5 than even the minimum theoretical limit of instability for thrust faults sliding on a smooth preexisting f racture. Preexisting f ractures that contain gouge within an irregular f ault zone, as does the tunnel fault, require yet higher stresses for movement. The sliding

, resistance imposed by the cohesiveness of the gouge is added to the i resistance provided by the 70-f t-thick " buttress" postulated by Voight (FSAR, Appendix D, p. D-57). This increase in resistance would require stresses measured in thousands of psi. Such a stress level far exceeds that presently known at the site.

i Figure 1 schematically shows the relationship between the tunnel f ault and the present-day stress regime. It can be seen that the minimum horizontal stress, if it is high enough relative to the vertical stress, is the stress direction that will cause thrust movement on the existing fault surface. To show the relationship between the ratio of 2

l. l i

those existing stresses, and the theoretical fields of thrust fault instability, we constructed Figure 2, in which we plot the ratio data of -

~

Roegiers (FSAR, Appendix E, table 11) in relation to the limits of the th rus t fault instability fields.

At the tunnel level, the stresses extrapolated f rom downhole in 4

boring TX-11 (FSAR, Appendix E) are of small magnitude, so that the stresses will not contribute to movement on the faults. For movement to occur, the minimum horizontal stress component parallel to the f ault dip

would have to increase by a f actor of 3 to 5 or more. This is a stress increase perhaps equivalent to continental collision or renewed I

f glaciation.

i In conclusion, available data suggests that the faults are stable under the present stress regime. Based upon the applicant's data and our analysis of stress we concur with the applicant's conclusion that t

the tunnel f aults are not capable and therefore do not pose a hazard to the category I structures of the Perry Nuclear Power Plant.

i i

t i

a 3

c i

0 v~

i' N mex

' \

- s b in A. p .. *""

%t e"d

\ I

} Mru<h rg min \ %i',i' 1%< '

stresses

% n ma i O

d by C~v Qe l

'" 16. , rgSen '

B. . .

sFreses  !

4 (dettA. ht-om q  ;'%'. Tx-il, Ape.E.) .

6A *# At ',

a naic,J a.o

%,>' %2 4 ,3',

rim r:tmu herit.*es. 4 3.q %. d 07r.,,< rnan m horis ec55 g* i i

Figwe .1.- RelaMnslugs hc 4 ween shess recj Ecs.

A,4o crecdc. 4unnel +hru% S, present clcq '

sfecsses Som hydroftc.cko4ngdo3cco(

FSAR Appech E.  ;

Perry N PP, fal revicvs.

3-s-et.

(usG6)M.H. Rd, Jc, +1.5. Svee@

u o

i I!

il il

@ ~;,, / rv o / 2 3 4 5 6 .

c.% a i _.

L lam f leved ~

/p p . La TktCII

-47 f f..& i ,

I

. .. . . 4u r.nel leve.\ l 8

7.te - [

l

, e e

{*

l l'j I

.~ 5 13

. "+vn p ol Aon I

• • • N

'{

l'

?

t +.

(ta 4 .r es i

. .k I2 1

+

% I <5 1.2 Ip

'y 480 - (e) e I

u g i, X 8 i l

'O It 0 i h-1%

l5 l-Ee I

Eimu m

<.4 re ra8 eno\cp

$ 648- (c) g ~ l.31 S

f g i

/ *h 3' r(A 3 ) pp.4 o I i 40*I 47*

A i j (s) O [ s Goo- I i -:

(D G I ,

I l l

60 t o i l I I i i 7oo -

@ le l I i

l I i l i G Recq/ css (Apf f ,R.th j .I ,

Q o.le 0.7 0. 8 c.f i'. o

,cuy..mua .;a-, nu,. ,

c~v Theoreb cel 4bru.h -fath in54c.

slidin$ ebili %,n pCie.ld 4r-re uisMng frmue .

Ryre 2.- Rela %nA;p b ebecn hyy to.h o end

% d .fo uit i s h M I, h4 4cid.

Pcyng N PP,[tda.\ revicvJ 3 6'?

(usGs)M.H.HA.Jr., M. bolo t