ML19309B889
| ML19309B889 | |
| Person / Time | |
|---|---|
| Site: | La Crosse File:Dairyland Power Cooperative icon.png |
| Issue date: | 04/03/1980 |
| From: | Hiestand O MORGAN, LEWIS & BOCKIUS |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| TASK-02-04, TASK-2-4, TASK-RR NUDOCS 8004070303 | |
| Download: ML19309B889 (9) | |
Text
,
MORGAN, LEWIS & BOCKlUS~
PHiLADELPHsA COUN S ELORS AT L Aw Los ANortes M
N Ew YOR M 18 0 0 M ST R E ET, N W.
1Mi PARIS H A9::e S B U RG WAS HIN GTON, D.C. 2 0 03 6 Tasse oac faoas e7a-sooo W
April 3, 1980 s
f, Of Docxnyo llSNRc '
APR 3
6-31SS),
NIe![dl8s"j87 y Mr. Harold Denton,~ Director Branch Office of Nuclear Reactor g
Regulation a)
U.S.-Nuclear Regulatory Commission Washington, D.C.
20555 Re:
Dairyland Power Cooperative (LACBWR)
Docket No. 50-409 (Show Cause)
Dear Mr. Denton:
There were a number of revisions to the original version of Dairyland's Answer to the Order to Show Cause, and the Dames & Moore Report which accompanied this Response, which were inadvertently not reflected in'the final version of this Answer filed on March 25, 1980.
These revisions primarily involve refinements of certain tables and graphs in the D&M Report and the characterization of related aspects of the Report contained in the Answer itself.
Enclosed are copies of corrected pages 3 and 6 of the Answer and pages containing corrected Table 2 and Figures 1-3 of the D&M Report.
Please substitute these corrected j
pages for the ones contained in the March 25, 1980 Answer.
We regret any inconvenience that this' oversight may have caused.
Sincerely,
- ~'s n:
s O.
S'. Hiestand Attorney for Dairyland Power Cooperative
/mbi cc:
Service List 8 004 070 3N9]3
i
-3 l
2.
Dairyland admits that the general discussion contained in Part II of the Show Cause: Order adequately sum-
)
marizes the events leading up to the issuance of the Show Cause Order, as well as the positions of the various parties involved in the analysis of the liquefaction issue.
- However, Dairyland denies each allegation, charge, and/or statement of fact contained in Part II to the extent that it is contrary to the information, data, and conclusions contained in the.D&M Response.
3.
Dames & Moore submitted a report on September 28, 1979 which demonstrated that the " threshold liquefication resis-tance level for the LACBWR site corresponds to a Safe Shutdown Earthquake (SSE) producing an acceleration between 0.18g and 0.20g at the ground surface."
Based on its review of the soils data contained in this report, the Staff has concluded that if sustained strong ground motion with peak accelerations of.12g or higher occurs at the LACBWR site, liquefaction can occur down to a depth of 40 feet.
The Staff determined that the soil strength curves contained in this D&M report, based on the ad-ditional soils samples taken by D&M pursuant to the NRC-approved soils properties investigation-program designed to determine the resistance of the soils at the LACBWR site to liquefaction, were 3/
"not adequately conservative." -
The Staff then adjusted.
-3/
The bases for this conclusion appear to be the Staff's belief that Dames & Moore (a) did not properly account for the effects of soil densification during sampling and testing, and (b) did not use the " Magnitude curve" corresponding to the Japanese' earthquake at Niigata while using the corrected SPT-N values in the empirical procedure.
Show Cause Order
.at 4-6.
-6 striaxial' test strengths'to account for the changes in densities
~
p'ointed out by the NRC_ Staff.
The factors of' safety identified in.the September 28 Report and the.D&M Response are valid and high enough to-demonstrate _ that ru) measures are necessary to mitigate against the liquefaction potential associated with seismic conditions producing a peak ground acceleration of.12g at the LACBWR site.
7.
In any event, the Staff has itself concluded that the general level of seismic hazard is sufficiently low to permit continued operation of LACBWR.
This conclusion is based upon the Staff's determination that the return period for
-an earthquake resulting in a peak acceleration of.12 g "would be at least 1,000 years" and that "the actual return period could be an order of magnitude higher."
Show Cause Order at 6-7.
The LACBWR site is located in the Central Stable Region where historically the seismic activity is very low.
Using seismicity data developed by the TERA Corporation for Lawrance Livermore Laboratory and the NRC, in conjunction with a computer program designed to perform seismic risk-analysis, Dames & Moore has determined that-the return period for an earthquake of this size is at-least 10,000 years and more likely between 10,000 and 100,000 years.
The seismic hazard perceived by the Staff is
-thus-low enough-to permit continued operation of LACBWR for the anticipated remaining life of the plant. -4/
4/
Dairyland's management recently approved plans to phase out the operation of LACBWR -by ~1990.
An amendment to the
'.pending FTOL application which will reflect this development is now being' prepared, E
t
g
, ;. m TABLE 2 h
SUMMARY
OF LIQUEFACTION' ANALYSIS ANALYSIS-TESTING APPROACH
[
ACCELERATION =.12 g
{
Free-Field Under Reactor T
2 3
Depth (ft) av T
FS T
S 3
ov T
FS 30 (top of 233 350 1.50 268 550 2.05
-reactor
(~
foundation) 35 265 410 1.55 304 650 2.14 P
L-40 290 480 1.66 332 750 2.26 45 315 540 1.71 359 840 2.34 l.
T*
cverage cyclic shear stress = (maximum cyclic shear stress from
=
one-dimensional analysis for free field conditions) x (0.65) 2.
T
=
cyclic shear strength under field conditions = (triaxial cyclic shear strength) x (0.57)
[
3.
FS factor of safety against liquefaction
=
4.
{
T, same as (1) above (see Note (1) below)
=
5.
t
=
(triaxial cyclic shear strength) x (0.9)
(L Note (1):
Driving 'of piles creates complex stress conditions which may be determined by more sophisticated analysis than has been done here. Cyclic shear stresses induced under the reactor have been approximated here by one-dimen-
{
sional wave propagation analysis with.12 g acceleration applied at the level of the top of the reactor foundation (depth 30 f t).
2
{
Note (2): All strengths and stresses are in Ib/ft,
[L g
r L-F r
J o.
I II 1I 1I 0.6 20-l 4 It
> 0.5 j
98 E
4
's 4
4 I
h $ OA d a L
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L
{
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[
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$3 0.1 2
oI
[
3h
$I
+c y
o 0
to 20 30 40 50 60 70 MODIFIED PENETRATION RESISTANCE Nj* blows / foot rL I
L CORRELATION BETWEEN PREDICTED PENETRATION RESISTANCE UNDER REACTOR AND FIELD LlOUEFACTION BEHAVIOR OF SANDS FOR LEVEL GROUND CONDITIONS F
BORING DM.7 L
F L
=== = = smoos
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hy amax.12g 66
=
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0 10 20 30 40 50 60 70 MODIFIED PENETRATION RESISTANCE Nj'-blows / foot r
u-I~L CORRELATION BETWEEN PREDICTED PENETRATION RESISTANCE UNDER REACTOR AND
- FIELD LIQUEFACTION BEHAVIOR OF SANDS FOR LEVEL GROUND CONDITIONS F
BORING DM-8 L
I L-,
~
names a moone FIGURE 2
0.6 Z
O h
4 88 l
\\ $ *
f e8 a
's 4
4 d a p h 0.4 IZ 05 a2
$E 0.3 o$
'c t i
- m 5
0.2 4 (n (0.16, 82)
- Q
{
}g amax.12g g
ee
=
m :s
$3 0,1 uZ 3 t:
0 10 20 30 40 50 60 70 MODIFIED PENETRATION RESISTANCE Nj'-blows / foot
[
[
CORRELATION BETWEEN PREDICTED PENETRATION RESISTANCE UNDER REACTOR AND FIELD LIQUEFACTION BEHAVIOR OF SANDS FOR LEVEL GROUND CONDITIONS 1
BORING DM 10 L
m ommusamoonu FIGURE 3
.q UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION Before the Director of the Office of Nuclear Reactor Regulation In the Matter of
)
}
DAIRYLAND POWER COOPERATIVE
)
Docket No. 50-409
)
(Show Cause)
(La Crosse Boiling Water
)
Reactor)
)
CERTIFICATE OF SERVICE Service has on this day been effected by personal delivery or first class mail on the following
- persons:
Charles Bechhoefer, Esq.,' Chrm.
Docketing & Service Section Atomic Safety and Licensing Office of the Secretary Board Panel U.S. Nuclear Regulatory U.S. Nuclear Regulatory Commission Commission Washington, D.C.
20555 Washington, D.C.
20555 Atomic Safety and Licensing Mr. Ralph S. Decker Board Panel Route 4 U.S. Nuclear Regulatory Box 190D Commission Cambridge, Maryland 21613 Washington, D.C.
20555 Dr. George C. Anderson Atomic Safety and Licensing Department of Oceanography Appeal Board University of Washington U.S. Nuclear Regulatory Seattle, Washington 98195 Commission Washington, D.C.
20555
4
-2 Colleen'Woodhead, Esquire Office of Executive Legal Director U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Steve Burns,~ Esquire Office of Executive Legal Director U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Richard Shimshak Plant Superintendent Dairyland Power Cooperative La~ Crosse Boiling Water Reactor Genoa, Wisconsin 54632 Fritz Schubert, Esquire Staff Attorney Dairyland Power Cooperative 2615 East Avenue, South
- La Crosse, Wisconsin 54601 Coulee Region Energy Coalition P. O. Box 1583 La Crosse, Wisconsin 54601 Attn:
Anne Morse Mr. Harold Denton, Director Director of Office of Nuclear Reactor Regulation-U.S. Nuclear Regulatory Commission l
Washington, D.C.
20555 I
il t
~ t A p _ '( w.
7; s
(
\\
0; S. Hiestand i
April 3, 1980
.