ML20037A642

Summary of 730215 Meeting W/Util,Dames & Moore & Corps of Engineers at Coastal Engineering Research Center Re Probable Max Storm Surge Estimates

ML20037A642
Person / Time
Site:	Crystal River
Issue date:	02/22/1973
From:	Hulman L US ATOMIC ENERGY COMMISSION (AEC)
To:	Gammill W US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 8003250652
Download: ML20037A642 (2)

Text

.

)

n-

~., _

^

~

%)%

r t

FEB 2 2 573 Willian P.

Gannill,~ Chief, Site Analysis Branch, L FEBRUARY 15, 1973 KEETING WITH FLORIDA POWER CORPORATION ON PROSAELE MAXIHUM STORM SURGE ESTIMATES FOR THE CRYSTAL RIVER NUCLEAR POWER PLANT, DOCKET 20. 50-302 On February 15, 1973, a meeting van held at the Coastal Esaineering 2csaarth Cantar of the Corps of Susincere (CE2C - our courultant ce the Regulacory staff on these matters) to discuss differeaces in probable caximun hurricane curge estimates of apprc=inately four feet for the subject site.

Attached is a Jist of the attendaes.

Ecyresentatives of Lance and Moore, censult:sts to the applicant, presented tha entheast1 cal and tefr'.cs1 t: es fer their hurricana surga nodel.

This infor-ation has not been availabic to the staff er eur consultant (0020) f o r p revie ns discusalona of atorn eurges for the Subjss; Jud Oth44-0i;54 Daa;4 uad Moors ;130 pr03 200 d' the results of parasatric stadiaa in which sev2ral different casumptions (of both Dases and Moore end CORC) of probable narimum hur:1cana paranerers and medal calibration coefficients werc nsad.

The results of these studias using.che Dames and Moore nodel indicated that surge estimages could vary substantially, depending pri--

narily upon. assumptions of the basic nodal calibration coefficients.- Furthermore, it was f ound-that t'a o tuo surge models saa produca different surge es timates when using the s aa'eDealib ration coefficients.

Surge model cakibratioafecaf ficients are b'asically of twel botton f riction' sad water surf ace' f ric tion'. s Dames

' ff]-

and Moota provided the technical bases forf their calibration ";.-~.

types:

- - coef ficients and presented the results-of studies made to

~ ~ '

verify their modal using a nistorical hurricane for an analytical' reproduction o f paah wate r level.

This

~

verificationJwas discussed in detail'.

4 Damas and Moora-representatives indicated that'as n part of the

~

vtrification,Jit was assumed that the historical-hurricane -

vind field (as presented in the literature) remained

-f cons tant for about 13. hours before th e.s torm cleared"the

- _, _ y

~T h

g, n

,,o

_ss-u.

UlH KIB y

gpg;

=

=

2-FEB 2 2 a73 Willian P.

Cammill

the coast lina.

Our consultant, Mr. D. E. Nunn, pointed out that this historical hurricane actually weakened con-sidorably as the stora mov.d onshora, and this was not considered by the applicant.

Therefore, dus to the use of isappropriata hurricane paranaters, the verification is not velid.

de further stated that a singular peak-surge eneck would be inconclusive even if the appropriate wind fields and associated parausters were used.

The-Dames and Moore model should be verified (for the total surge hydrograph and not just the peak only) by accurately reproducing several different hurricanes at several different shore locations with the appropriate wind fields and other parameters, including tining and forward speeds, yor instanca, the original calibration studies of heir model by the Corps of Engincors (as published by Cecrga Marinos and Jarry Woodward, ASCE - Journal of Waters and Harbors Division. May 1960), about 6 different recorded burricanes along the Culf coast and their appropriata track and parlaaters vero used ce twetoduco recorded surgo hydrographa at vart ow4 tocations (iocut 12 hydrographs in all).

Tha 03astal Zagis;;ria; 5.ca u a rc.

sr improved the origiual nodal Cup Marinos and Woodward'; Ly aodifying bottom struss coefficients and the vini, cress ralatioa6 and rep roduced

.o Galvaston aufga hydrudraph for he:cicane Ccmilie.

Preliziacry cospurison of tae oriSinel mods 1 vith t,he current CERC nodal on hypothetical hurricanes indicare no significant differences in the racults obtained froc the two nodels.

'dovover, farther varificatica is needad using hurri' canes'aur'surgea of record :o assure there is no significadr ' difference in the two models.

~

Discussion of the technical basas for the Dauas and Moore i

surgefabdel indicated that_the nunarical. techniques employed (exalmatve of calibration coef ficients) could reduce truncation errors'in storm surge estiastes; and could tend T

~

l l

s te pteduce thigher surgef estimates than would mathematical.

techniques'which de metjeffectively reduce.er" eliminate-7

.truasationierrors.sfDiscussions ofcthe CIRC,model indicated

- ths' pds'aibilityk th'at some^ truncation. arrers might develop

~

and, therefore.^the-use of the CERC medal could possibly underestinats surgs#1evels.

Horover, it was noted that CERC n-l f; fealibration _coef ficients,2 based ~ upon reproduction of'saveral

/G' historical hurrisene surges, woulds tead to compensate for'

_. 7 ' truncationle'rrerar.T Although'some verification of the CERC-

.. ' n me~de1 has'heam'heimplaced,'{it was noted that additional work

~

J

1. M v' uld' be[iregini' ired.:tf assare ' Ehat n'e'eurate calibration _

o d eaefficientsiyforei eing used.~' - _

b f.

-i' mm 7._

xw j, sk.-

[i. - 1 : ~,

X-*

D-~

"Jillita F. Gemmill pgg g 4,, p cid The two prinary dif f erences between the D:=es and Necre and CERC modsla appear to be in the numerical techniques being used, and the aesumptions of botton and surface friction calibration coefficients.

Traditica:117, calibration coefficients are developed by reproduction of histertral surges.

Thess :cefficients, however, are calibration function of the nodel being esployed and the acoefficients for the two models can not be conpared directly.

It was felt, however, that if the Dames and Moore model was more ecapletely verified by reproducing several historical hurricanes, and the CERC model was refined to reduco truncation errors and then recalibrated, more conpatible surge estinates for the Crystal River site could probably be produced.

Danes and Moore The undersiEned requested CERC te reviev the nodal in detail to further decernine its ralidity, sud to investigate wascher it is necessary to sodify the CERC nodel to reduce truncation errors and undertake the required reca11Leation.

Cancs ced Moore provided their scorn 6arge nodel and saveral corputer runs tc the undersi;ned an :

proprietary baais.

C212 aae best asked to treet the Dines and Xcore infernstion as proprietary.

Iha unde r31;nud and cur condaltant. CI2C as rc:ranented by se:11 water 14:21 30.'

Mr.

1. Jacacvakt. concludec ras s

fact above nee low vster is required at the Crystal niver plant site seaed upon preseatly avallisla estiza:12n tecaniq=ca.

Hawever, this cculd ha nodified 511ch:ly upwards or devnvards as a resalt of additional research on models and medal. calibration coefficiests.

Furthernorc, the Danes and Itocre andel uas considered to represent possible advances in surge astinsting nodels (pcading detailed review confirmation), but calibration by the comaultant is unacceptable since only one historical peak water level reproduction had been hurricane surge undertaken.

This reproduction used incorrect. wind field and pressbre data.

It is noted that-couplete surge hydro-graph reproduction for several storsa at esveral locations is ganarally required to provide acceptsble verification of both nodel and calibration coeffietects.

L.

G.

suiman, 34sior Cydraulie Engineer 31:e Analysis 3 ranch gh

_,,gg g g {

Og VW Inclosure ut.c ex.tcensees

}.~.4..h$.

y U

e.

}

u u{

- - ~.

e sy,,q,, 4 ~

g

%y.N ' j y sa:g See attach,ed.sh'et -

_l

.o e

s a pw 4

y; mw

[

q w---...

t u

~

~.

y;.

a-s -

s.-

m

.e_.

FEB 2'2lG73:

~'

W1111an P. Gammill-.

cc:

v/anciosure H.

R.

Denton A.

Ctambusso A.

Schwancar H.

Faulkner 3.

Sucklay 9

-R.

Jachowski, CERC-E D

D. Nunn, Consultant u

'% $)

sb DISTRIBUTION 9

LDocket File L:Rd; L:5A3 L:AD/SS cmer >

..L. ".S A3

~

f LE3A3 E'CX

.,1 D j V.J-- i-b suawat > l. gay,31,sTW,,,LGHulman 9

1

.. 2./.2 2./.D......l. 2 LEF_/.Z 3 om.

r_.uc..i.,u.

m acu g,o

... ->-~ ~,own

~.

s LIST OF ATTENDEES DAMES & MOORE Run Noble, Los Angeles Dr. James A.

Hendrick, (Exec. Offices) Los Angeles DAMES & MOORE CONSULTANTS Charles L.

3retschneider, Consultant Ricahrd O.

Eaton, Consultant FLORIDA POWER CORPORATION John A.

Hancock ATOMIC ENERGY COMMISSION L.

G.

Hulman hh ATOMIC ENERGY COMMISSION CONSULTANTS

.3 o

'5\\' * ~

g Dwight E.

Nunn, Nunn, Snyder & Associates NCAA C.

?.

Jelesnisaski CERC Robert A.

Jachewski 3.

P.

3vdine Barry E.

Herchenroder CERC CONSULTANT Robert O.

Reid, Texas A&M University

_/

s