ML19242C484

Cask Drop Analysis

ML19242C484
Person / Time
Site:	Mcguire, McGuire, 07002623
Issue date:	08/02/1979
From:	DUKE POWER CO.
To:
Shared Package
ML19242C483	List: ML19242C482 ML19242C484
References
NUDOCS 7908100473
Download: ML19242C484 (6)

Text

_

McGuire Nuclear Station Cask Drop Analysis In order to allow an alternative to the use of the Duke Power Ccmpany NFS-4 cask for the shipment of spent fuel from Oconee Nuclear Station to McGuire Nuclear Station, we submit the following information concerning the use of an NLI-1/2 cask.

This nualysis evi.luates the consequences of dropping or c.ipping, or a combination of..both, of the NLI-1/2_ cask in the McGuire spent

,Eual handling building f

~

The NLI-1/2 cask is a truck cask licensed by National Lead Company and is Model No. NLI-1/2. The cask weighs approximately 25 tons and is 200 inches long in-cluding top and bottom energy absorbers. The area in which the cask is handled is designed for a 30 foot drop of a proposed 100 ton rail cask and the struc-ture is reinforced concrete with a rock foundation. Local damage to the con-crete will be negligible and no safety related equipment is located in the cask travel path. The following circumstances of dropping the cask were considered to be most critical and the assumptions and conclusions are presented:

Case #1 - The cask handling crane is assumed to be traveling at its maximum speed of 50 fpn and hits the crane stops nearest the spent fuel pool. The crane stops, and the cask is assumed to continue traveling toward the spent fuel pool rotating about a line through the cer'erline of the crane drum.

The cask continues to swing until the kinetic energy is completely converted to potential energy (i.e. the cask raises up as it rotates about the crane drum). At the instant the cask swings as close to the spent fuel pool as possible, the cable breaks and the cask falls. The conclusion is that the cask falls on the edge of the spent fuel pool wall and falls away from the spent fuel pool due to its center of gravity being behind the wall. See Sketch #1 for an illustration of this case.

Case d2 - The cask handling crane is assumed to be traveling at its maximum speed of 50 fpm and hits the crane stops neartst the spent fuel pool. The crane stops and the cable breaks at the same instant, therefore the cask does not swing but is moving at 50 fpm. The cask is assumed to be at its highest position, which is approximately 4 feet off the floor. The distance the cask travels at 50 fpm in the time it takes for the cask to fall 4 feet is deter-nined. The cask will hit the spent fuel pool wall and tend to rotate about its edge on the wall.

It is determined that the amount of kinetic energy is not sufficient to cause the cask to fall into the spent fuel pool. See Sketch d2 for an illustration of this case.

Case d3 - The cask is assumed to be over the edge of the cask pit wall and the cable breaks. The cask either drops on the edge of the wall or the cask is lowered on to the edge of the wall. Either case gives the same initial conditions because in the event of a drop the kinetic energy is assumed to be absorbed by the cask's bottom energy absorber. Therefore, the cask's potential energy will cause the cask to tip toward the spent fuel pool wall.

Energy losses at impact with the spent fuel pool wall are conservatively con-sidered and the results of the analysis show that the remaining energy is not sufficient to cause the cask to fall into the spent fuel pool. See Sketch 43 for an illustration of this case.

1 790810co s

~

SMo7(

McGuire Nuclear Station Cask Drop Analysis, con't.

In order to provide additional assurance that the cask will not fall into the spent fuel pool, the path of the cask will be controlled by application of administrative control as shown on Sketch #4.

By requiring the cask to follow this path, the circumstances of Case #3 cannot occur and any potential for the cask falling into the spent fuel pool is negated.

2 g]2[ $

[

J~

~ ~~'

t 4_. Crane Drum nl Crane Against stop3 1

11 l

i 4

L_

7-I l

I l

l I

^W I

i i

emTruck Cask - Model No NL11 2

7v i

I O

I I

th-1 I

i co.

1 I

i i

i a

I I

I I

I I

1 - t--

i i

i I

i i

I i

[

l I

I I

I I

i I

1 I

l I l

_ _1._,

i j

l i

i l

i

_2 i

I y

i l

' - ~

~ '-

Cask Pit Fuel Pool i.7-0 I

I c co. _ I 2;.

_e c_ _,,_ o.

d) ' V* 4 u.-f M EIC.H

4 l

f 1

NTruck Cask - Model No NLI l I

a

i i

-- q j

p_.

i e

i e

g L_. 7_ _ 7 - ~~T-J l

l l

i l

I i

I I

I I

I I

l i a

\\

v t_

I i

l I

I I

l l

I I

I I

. _I g_

{.__

l i

l ill I

I i

I I

i1 1

I ll l

l i

7 I

ll I

of l

.i l

y

,. _ z.-

u.

1 i

i i

l i

i t_

i l

'^

• Cask Pit l

, To_ L 5 Nel F"I ac l

YA

n. - u n - f.

C"AbICh 47L

i i

i i

i l J ruck Cask -Model No. NLI 'z T

I I

l i

I l

I I

I i

l1 Water Jacket Gyp.)

I I

I rw I

m I

I i

i i

l I

i l

l

'/

/

I l

/

l i

\\/,/ /,f '

i I

u l,

/

/

/

\\

W -~'

f _,/

y..

I y;

/

Cask Pi+

Fuel Pool TO 5'-O '

s N

I N

N N

's s

's N

N 1

N N

A man,/

N

\\

y s

N N

/

's G

s.

____2______.

w__-_

g s

~

n..,..

I x

s N

\\

Cask Pit N

CT-O 5-O,'

nn<'~',

r-

~

v. m.

uel Pool bKE.TCH *$

4 SI n

_ _ _ _ _ _ _._ _ _ _ _ _ _ _ _ _ f, Edreme of Main %k I

I i

I l

n l

H[

A 3

Q sf

.ol a

I

~

r v

I

~\\

M l

}

f l

_f e

I r-m

-l l

l L

1 u

+

---

4 50 I

3 3

pl a

e Cask Pit i

o Fuel Pool F

S I$6 6-0,

d:.9 i-l s

=

o l

l

~

D f

l r

l

~d5 I

I Ik, I

ye bJ l

Oi uJ b

i l

j

<r I

N' i

<a i

b l

l i

1 i

D i

m m

54

}"

I l

Gr

/

i f

I l

=_

--f_

i I

-_ f 4q raw f L~v ~ -.' b W F_TC H h