ML17255A638

Tornado Missile Accident Analysis for Spent Fuel Storage Racks for Rochester Gas & Electric.

ML17255A638
Person / Time
Site:	Ginna
Issue date:	10/04/1983
From:	Linder R, Wachter W, Waite H U.S. TOOL & DIE, INC.
To:
Shared Package
ML17255A634	List: ML17255A632 ML17255A635 ML17255A636 ML17255A638
References
8367--5, 8367-00-0005, NUDOCS 8401250303
Download: ML17255A638 (19)

Text

TELEPHONE (412) 961-0323 U. S. U. S. TOQL R QIE, INC.

An NPS Corp. Subeldiery 4030 ROUTE 8 ~ ALLISON PARK, PENNSYLVANIA 15101 K)RNADO MISSILE ACCIDENT ANALYSIS SPENT FUEL STORAGE RACKS ROCHESTER GAS AND ELECTRIC 8367-00-0005 OCTOBER 4, 1983 PREPARED BY Harold H. Waite KEENED BY Will '.

7 c .

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'ATF/8 Wachter APPROVED BY

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Engineering Manager c 8D Frank E. Witsch e40iVSOSOS BOOS>8 QGa13.~ AssQx'ance Manager PDR ADOCK 05000244 P FOR

PAGE 1 OF 16 STATEMENT OF PROBLEM:

DETERMINE THE EFFECT ON THE SPENT FUEL RACK CAUSED BY THE IMPACT OF A MISSILE, AS DEFINED BY ROCHESTER GAS 6 ELECTRIC, BEING A POLE 12.5 INCHES IN DIAMETER, 35 FEET LONG AND WEIGHING 1490 POUNDS. THIS CORRESPONDES TO THE MISSILE DEFINED IN REFERENCE ¹4 AS A 13.5 INCH DIAMETER, 35 FOOT LONG UTILITY POLE, WEIGHING 1490 POUNDS.

CONCLUSION:

THIS ANALYSIS DEMONSTRATES THAT THE IMPACT OF THE MISSILE WILL NOT IMPAIR THE INTEGRITY OF THE RACK TO MAINTAIN ITS SUBCRITICAL GEOMETRIC ARRAY.

INTRODUCTION:

A 35 FOOT LONG POLE, 13.5 INCHES IN DIAMETER AND WEIGHING 1490 POUNDS COULD BE A SUGAR MAPLE WOOD HAVING A DENSITY OF 43 LB/SQ.FT. THE POLE WOULD IMPACT THE RACK WITH THE FORCE ON THE POLE PARAI,LEL TO THE GRAIN.

PROPERTIES OF SUGAR MAPLE -12 4/i MOISTURE CONTENT- FROM REF ¹6.

MODULUS OF ELASTICITY 1.83E06 PSI MAXIMUM CRUSHING STR. PARALLEL TO GRAIN = 7830 PSI MAXIMUM SHEARING STR. PARALI.EL TO GRAIN = 2330 PSI LOAD REQUIRED TO IMBED A 0.404 IN. DIAM. BALL TO 1/2 ITS DIAM. 1450 LB.

WHEN THE POLE'MPACTS THE RACK CONSIDERABLE ENERGY Wl I L BE ABSORBED BY THE POI.E. ANYONE WHO HAS USED WOODEN MALLETS OR DRIVEN ON h PIECE OF WOOD HAS OBSERVED HOW QUICKLY THE EDGES AROUND THE ENDS WILL SPLIT AWAY AND HOW THE ENDS BECOME VERY FIBROUS.

IN THIS REPORT THE ENERGY ABSORBED BY THE POLE IS NEGLECTED' FULL SCALE TEST WOULD HAVE TO BE DONE IN ORDER TO DETERMINE WHAT ACTULLY HAPPENS TO THE RACK. A 3-D FINITE ELEMENT ELASTIC-PLASTIC ANALYSIS WOULD GIVE EXCEI.LENT INSIGHT INTO HOW THE FORCES ARE DISTRIBUTED THROUGHOUT THE RACK. HOWEVER THIS TYPE OF ANALYSIS IS LABORIOUS AND EXPENSIVE.

WACHTER ASSOCIATES PERFORMED TEST DEMONSTRATING THAT THEIR RACKS..

"'"" WOULD'ITHSTA'ND A 9000'FT-LBMISSILE 'LOAD (REF. ¹2);. THESE TESTS WERE DONE ON A SINGLE BOX WHICH WAS ADEQUATE FOR THE 9000 FT-LB L'OAD. THE IMPACT FORCE IMPOSED BY THE MISSILE UNDER INVESTIGATION IN THIS ANALYSIS IS SEVERAL TIMES GREATER TROJAN THE "WACHTER" MISSILE. THE COMPOSITE RACK AS A HONEYCOMB STRUCTURE MUST BE RECOGNIZED TO DEMONSTRATE THE ADEQUACY OF THE RACK.

PAGE 2 OF 16 VERTICAL IMPACT:

TYPICAL RACK, SHOWN ON FIG. ¹1, IS MADE UP OF 140 BOXES, 8.43 INCHES SQUARE WITH A 0.090 INCH THICK WALL. THE BOXES ARE WELDED TOGETHER TO FORM A HONEYCOMB TYPE STRUCTURE. THE INTERNAL BOXES ARE ATTACHED TO EACH OTHER BY WELDS. THE GENERAI ARRANGEMENT OF THE WELDS IS SHOWN ON FIG ¹8. THE TOTAL WELD SHEAR AREA ON ONE BOX IS.'2 EA. 1/2" DIAM. FUSION WELDS ~ 2. 36 SQ. IN.

20 EA. 2" LONG FILLET WELDS ' 7.20 SQ.IN.

(Assume fiiiet welds 0.18 " thk) h EA. 1" FILLET WELDS 0.72 SQ.IN.

TOTAL WELD AREA 10.28 SQ ~ IN.

ANY VERTICAL LOADS APPLIED TO A BOX WILL BE TRANSMITTED TO THE OTHER BOXES VIA THE WELDS. A FORCE APPLIED TO A SINGLE BOX FROM ANY DIRECTION WILL BE REACTED BY THE COMPOSITE HONEYCOMB STRUCTURE.

THE SECTION OF THE RACK ENCOMPASSED BY THE IMPACT LOAD WIIL ACT AS COLUMNS UNDER COMPRESSIVE LOADING UNABLE TO BUCKLE.

THE ELASTIC STRAIN ENERGY WILL BE:

P L/2AE (REF ¹5)

'HERE: P ~ IMPACT LOAD L ~ COLUMN LENGTH A ~ CROSS SECTIONAL AREA RESISTING THE LOAD.

E ~ YOUNG'S MODULUS THE EVALUATION OF THE EFFECT OF THE MISSILE IMPACT ON A 'RACK

~ '-'IS'ONE-USING THE STRAIN 'ENERGY METHOD DESCRIBED 'IN REFERENCE., ~

¹3, SECTION 2.8-0. AND REF ¹5 CHAPTER XI.

THE RACKS EXHIBIT ENERGY RESISTANCE:

Uu ( in-Ibs/ in. )

THIS IS FOUND US ING THE AREA UNDER THE STRESS STRAIN CURVE (STRAIN ENERGY) SHOWN IN FIG. ¹5.

PAGE 3 OF 16 Uu = (Sy + Su)Ka/2 AND U = Uu z A x L WHERE: Sy = YIELD STRENGTH Su = ULTIMATE STRENGTH Ka = ULTIMATE UNIT ELONGATION U = ENERGY IMPACTED TO THE RACK A = CROSS SECTIONAL AREA ABSORBING "U" L = LENGTH OVER WHICH "U" WILL BE ABSORBED.

USING Sy ~ 30,000 psi and Su = 70,000 psi Uu ~ 50,000 Ka ENERGY IN Ml SS I LE:

THE HORIZONTAL TORNADO VELOCITY IS GIVEN AS 132 MPH.

(132 MI/HR)<5280 FT/MI)<HR/3600 SEC) 194 FT/SEC HORIZONTAL VELOCITY ~ 0. 4 < 194 ) = 78 FT/SEC VERTICAL VELOCITY ~ 0.8<78) = 62 FT/SEC.

WHEN THE MISSILE ENTERS THE POOL THE KINETIC ENERGY IS REDUCED AS IT MOVES THROUGH THE WATER. THE KINETIC ENERGY AT POINT OF CONTACT IS FOUND FROM REF 01.

Z ~ CdAcs/W WHERE: Cd = DRAG COEFFICIENT = 1.0 Acs ~ CROSS SECTIONAL AREA ENTERING POOL W = WEIGHT OF MISSILE (LBS>

D = 12.5 in.

A = 0.852 SQ.IN.

Z ~ 0.852/1090 = 0.0006 FROM CURVES FOR 20 FT DEPTHS AND .34,.FT DEPTH KE/W EQUALS 55 AND '00 'RESPECTIVELY'.NTERPOL'ATING FOR 25 FEET, DEPTH UNDER WATER OF RACK, KE/W = 53 FT-LB/LB.

KE s <53) 1490>

< = 79,000 FT-LB.

PAGE 4 OF 16 THE VALUES OF A (AREA) AND L (LENGTH) TO BE USED IN THE EQUATION ARE ARBITRARY. OBSERVING FIGURES ¹2 AND ¹3 THE AREA UNDER THE MISSILE A SHORT DISTANCE DOWN FROM THE POINT OF IMPACT IS RESISTED BY A MINIMUM OF 24 BOX SIOES.

A = (24) (8. 43 + 8.25) <0. 09) /2 "- 18.0 SQ. IN THE LENGTH OVER WHICH THE ENERGY IS ABSORBED CAN VARY UP TO THE TOTAL I ENGTH OF 160 INCHES. AS THE LOAD MOVES DOWN THE BOX IT WI LL SPREAD OUT AT APPROXIMATLEY A 45 DEGREE ANGLE.

THE TEST BOX IN REFERENCE ¹ 2 WAS 15 INCHES LONG. IT IS REASONABLE TO ASSUME 30 INCHES AS A CONSERVATIVE LENGTH.

A x L = 540 CU. IN.

U = Uu x A x L 540 Uu 79,000< 12) /540 ~ 1755 IN-LB/CU. IN.

Ka. = 1755/50,000 = 0.035 IN/IN TOTAL DEFORMATION = 0.035(30) = 1.05 IN.

IMPACT AT PERIPHERY OF RACK:

A VERTICAL IMPACT LOADING SHOWN ON FIGURE ¹4 IS ASSUMED.

18 BOX SIDES WOULD ACT TO RESIST THE LOAD.

A = 18 ( 18/24) ~ 13. 5 SQ. IN.

U = (13.5)(30)Uu = 405 Uu Uu = 79,000(12)/405 ~ 2340 IN-LB/CU.IN.

Ka = 2340/50,000 = 0.007 IN/IN.

TOTAL DEFORMATION = (0.047)(30) = 1.40 IN.

\

PAGE 5 OF 16 HORIZONTAL IMPACT A MISSILE IMPACTING THE. RACK FROM THE SIDE WILL BE REACTED BY THE SIDES PERPENDICULAR TO THE fACE OF THE MISSILE,. THE HORIZONTAL IMPACT LOAD WIIL ACT ON THE RACK AS SHOWN GN F I GURES 06 AND 07 .

THE RACK IS FREE STANDING AS SHOWN IN FIGURE 06. HOWEVER THE SEISMIC RESTRAINTS LOCATED AT THE BASE OF THE RACK WILL TEND

'O MAKE IT BEHAVE AS A CANTILEVER BEAM WHEN IMPACTED BY A M I SS I LE AT THE TOP .

THE INITIAL VELOCITY OF 78 FPS WILL BE REDUCED AS IT TRAVELS THROUGH THE WATER. IT IS ASSUMED THAT THE VELOCITY WILL REDUCE BY AT LEAST 10 '%R TO 70 FPS.

AS THE MISSILE IMPACTS THE TOP OF THE RACK THE KINETIC ENERGY IS REDUCED TO:

2 KE = WbV (C1/(1+(We/Wb) I) /(2g)

WHERE:

Wb = WE I GHT OF MI SS I LE Wm = WEIGHT OF RACK ASSEMBLEY We = EQUI VAI,ENT WEIGHT OF THE MEMBER

0. 236 Wm V = INITI AL VE LOG ITY THE WEIGHT OF THE RACK, Wm, IS USED AS THE WEIGHT OF THE EMPTY RACK PLUS THE ENTRAINED WATER.

W< ent) = (8. 25) 2 (160) (62. 4) (140) /1728 55,000 lb.

W( Rack) 20,000 lb.

W(Total) 75,000 lb.

We = 0.236 x 75,000 = 17,700 lb.

KE = (1490) (7) 2 (1/C1+(17,700/1490) i) /(2g) 8800 FT-LB THE ALLOWABLE ENERGY LOAD, OR I OAD THAT CAN BE ABSORBED ELASTICALLY IS:

U = <0. 16667Sy L/E) ( I/c )

WHERE: I = MOMENT OFINERTIA OF'ACK' c = DISTANCE TO NEUTRAL AXIS I/c = IMPACT LOAD STRENGTH

PAGE 6 OF IN THE NORTH-SOUTH DIRECTION 2 = (I I/c = 489,900/(59) 140.8 SQ.IN. FROM P.7)

IN THE EAST-WEST DIRECTION I/c " = 226,720/(42.15) ~ 127.6 SQ.IN.

Umin = (0.1667)(30,000) <160)(127.9)/(28E06ai2) c.'1 00 FT-LB THIS IS LESS THAN THE KINETIC ENERGY FROM THE MISSILE IMPACT.

THE HORIZONTAL LOAD IS CARRIED THROUGH THE RACK BY .THE SIDES OF THE BOXES AS SHOWN ON FIG. ¹7. THE SECTION BETWEEN THE BOXES MUST MAINTAIN ITS STRUCTURAL INTEGRITY TO CARRY THE LOAD. THESE SECTIONS BEHAVE AS A COLUMNS WHERE:

I ~ BH /12 (8.25)<2)(0.09) /12

0. 124 IN.

r ~ I /A = 0. 124/0. 74

0. 408 8 "-(T E/ ( L / R), ( EULER ' FORMULA) 1 . 7E09 PS I THE SECTIONS BETWEEN THE BOXES WILL CARRY THE LOAD FROM ONE BOX TO ANOTHER WITHOUT BUCKI,ING.

PAGE 7 OF IG MOMENT OF INERTIA OF THE RACK

-lg d

-I I d 9d 75d a

(I 3d d

)8.25~

Ibos = (bo4 - b, ) /12, 34.81 in. 4 E4.3 Ahoy ~ <bp 2:2 bI )

t

=3.00 in.2 I -"51's +/Ad 2 Na = NUMBER OF BOXES PARALLEL TO THE AXIS ABOUT WHICH THE MOMENT OF INERTIA IS CALCULATED.

Nb = 1/2 OF THE NUMBER OF BOXES PERPENDICUI.AR TO THE AXIS ABOUT WHICH THE MOMENT OF INERTIA . IS CALCULATED.

i=<2Nb-1)(in increments of 2)

ZNat lib a boa + Ad (~(i~ )g i=1 FOR NORTH-SOUTH SEISMIC LOADING Na ~ 10, Nb = 7, In-s = 489,900 in.4 An-s = a<20) (0;.0.90) (118'.'0'2) ~

"2 212.'4 .i.n..

FOR EAST-WEST SEISMIC LOADING Na = 14, Nb = 5, I e-w = 226, 720 in.A Ae-w = (28) <0.090) (84.3) ~ 212. 0 in.2

ZOCOO LBS Ml SSI L E IMPACT ARE A INSIDE PERIPHERY QF RAC K SID E'S RES IS Tl NG IMPAC T'OAD

AG E I 0 OF l6 Fi GUPE NO 3 M I SSI LE IMPAC T A RE A INS ID E PERIPHERY OF' pgIr, SI DE S R ESI S T I NG IMPACT LOAD

AGE I I OF IG Ft GURE NO 4 MISSILE IMPACT AWE A AT P EP.IP HEPY OF RAC 8

~l-l ]

SIDE S RES IST! NG IMP AC T L 0 AD I NG

PAGE I2 OF I6 Fl Gu 8 t:- NC.5 UH I T STRESS Su Sy UNI T ST R A IN

PAGC I 3 OF IG F)GuRv NO.6 HOAtZONTA L IMPACT FC ACE

L=lG0 R E No-7 HGR IZO N T A L IMPAC T FORCE BC X

~ ~

4 P E i5 OF ij-f= iC,uRc ~O. e WF LOS I iNCH F ILLE T V/ELDS Ig DIAM FU SION WELDS r2 INCH NELDS FI L LE T

0 PAGE 16 OF 16

REFERENCES:

1. D.R. Miller, W.A. Williams, TORNADO PROTECTION FOR THE SPENT FUEL STORAGE POOI., APED-5696, Class 1, Nov. 1968. Atomic Power Department, G.E. SanJose, Cal

2. SPENT FUEL STORAGE RACKS-FUEL BOX CRUSH TEST; Report and Calculations, 4907F17, Wachter Associates, INC.,

1/2/80.

3. ,Orner W. Blodgett, DESIGN OF WEI.DED STRUCTURES, James F.

Lincoln Arc Welding foundation. Clev. Ohio.,1975.

NUREG-0800, V.S. Nuclear Regulatory Commission, Standard Review Plan, 3.5.1.0, MISSILES GENERATED BY NATURAL PHENOMENA., Rev. 2, July 1981.

5. S. Timoshenko, STRENGTH OF MATERIALS, Part I.

D. Van Nostrand Co. Inc.,N.Y.N.Y., 1955.

6. OW. Eshbach, M. Souders, HANDBOOK OF ENGINEERING FUNDEMENTALS, John Wiley 8 Sons, N.Y.N.Y., 1974.

Attachment C In accordance with 10CFR 50.91 this change to the Technical Specifications has been evaluated against three criteria to determine if the operation, of the facility in accordance'ith the proposed amendment would:

involve a significant increase in the probability or consequences of an accident previously evaluated; or

2. create the possibility of a new or different kind of accident from any accident previously evaluated; or

3. involve a significant reduction in a margin of safety.

As outlined below, Rochester Gas 6 Electric submits that the issues associated with this amendment request are outside the criteria of 10CFR 50.91, and therefore, a no significant hazards finding is warranted.

Attachment B presented an analysis of the dose consequences.

resulting from the impact of a tornado missile. Because of the limited deflection of the rack (1.4 inches) on impact, and the, 2 of 4 storage space configuration, it is impossible to postulate damage in excess of a total number of rods equivalent to five

'ut fuel assemblies. 'sing a conservative X/Q value, considering the assumed tornado conditions, results in a dose at the EAB of 60 rem. This is well within the guidelines of 10CFR 100 and is less than what the NRC considered acceptable for the fuel handling accident inside containment (96 rem).

Therefore a no significant hazards finding is warranted for the following reasons:

There is no increase in the probability of impact of a tornado missile on spent fuel. The consequences were evaluated to be less than what the NRC considered acceptable previously because a more appropriate X/Q value for the postulated tornado condition was used.

2. The possibilty of a different kind of accident is not created.

"3. There is no significant reduction in the margin of safety. The consequences of such an accident are less than previous results.