ML20058A972

NNFD-SA-2 Shipping Container Safety Analysis

ML20058A972
Person / Time
Site:	07105910
Issue date:	10/31/1990
From:	BABCOCK & WILCOX CO.
To:
Shared Package
ML20058A970	List: ML20058A967 ML20058A972
References
NUDOCS 9010290330
Download: ML20058A972 (66)

Text

- _ - _ _ - _ _ _ _ _ _ - - _ _ _ _ _ _ _ _ _ - _ _ _ - _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _

0 o

USA /5910/B( )F (NRC)

NNFD-SA-2 SHIPPING CONTAINER SAFETY ANALYSIS Published October, 1990 The Babcock & Wilcox company Naval Nuclear Fuel Division Lynchburg, Virginia o01029033o 901026 ADOCK0710ggO DR

o ABSTRACT The NNFD-SA-2 Shipping Container, USA /5910/B( ) F, is used for shipping fuel elements via an approved carrier.

The Model NNFD-SA-2 container has been in service since 1970.

The current Certificate of Compliance No. 5910, Rev.

4, is dated October 24, 1984.

The purpose of this report is to consolidate the supporting documentation and to present the evaluation in a format consistent 6

with Regulatory Guide 7.9.

It consists of an inner box and an outer birdcage overpack designed to meet the requirements for Normal Conditions of Transport and of the Hypothetical Accidents.

The authorized uranium fissile content limit is 4.0 kilograms of U-235.

The container has been evaluated to demonstrate that the NNFD-SA-2 Shipping Container has an adequate margin of safety to ensure sub-criticality when loaded with the maximum permitted quantity of fissile materials in the most reactive configuration, and subject to the maximum credible accident conditions.

The analysis and testing has shown compliance with Standards for Nor mal Conditions of Transport and with the Hypothetical Conditionts of Transport in accordance with 10CFR71 for radioactive shiFPing containers.

o s

TABLE OF CONTENTS 1.0 GENERAL INFORMATION B4m 1.1 Introduction 1-1 1.2 Package Description.

1-1 1.2.1 Packaging 1-1 1.2.2 Operational Features.

1-2 1.2.3 Contents of Package 1-2 1.3 Appendix 1-2 2.0 STRUCTURAL EVALUATION 2.1 Structural Design.

2-1 2.1.1 Discussion 2-1 2.1.2 Design Criteria.

2-1 2.2 Weights and Centers of Gravity 2-1 2.3 Mechanical Properties of Materials 2-1 2.4 General Standards for All Packages 2-2 2.4.1 Minimum Package Size.

2-2 2.4.2 Tamper-proof Device 2-2 2.4.3 Positive closure 2-2 2.4.4 Chemical and Galvanic Reactions 2-2 2.5 Lifting and Tiedown Standards for All Packages 2-2 2.5.1 Lifting Devices 2-2 2.5.2 Tiedown Devices 2-2 2.6 Normal Conditions of Transport 2-2 2.6.1 Heat 2-3 2.6.1.1 Summary of Pressured and Temperatures 2-3 2.6.1.2 Differential Thermal Expansion.

2-3 2.6.1.3 Stress Calculations 2-3 2.6.1.4 Comparison With Allowable Stress.

2-3 2.6.2 Cold.

2-3 2.6.3 Reduced External Pressure 2-4 2.6.4 Increased External Pressure 2-4 2.6.5 Vibration 2-4 2.6.6 Water Spray 2-4 2.6.7 Free Drop 2-4 2.6.8 Corner Drop 2-4 2.6.9 Compression 2-5 2.6.10 Penetration.

2-5 2.7 Hypothetical Accident Conditions 2-5 2.7.1 Free Drop 2-5 2.7.1.1 End Drop.

2-5 2.7.1.2 Side Drop 2-5 2.7.1.3 Corner Drop 2-6 2.7.1.4 Oblique Drop.

2-6 2.7.1.5 Summary of Results.

2-6 2.7.2 Puncture.

2-6 2.7.3 Thermal 2-6 2.7.3.1 Summary of Pressures.

2-6 2.7.3.2 Differential Thermal Expansion.

2-6 2.7.3.3 Stress Calculations 2-7 2.7.3.4 Comparison with Allowable Stresses.

2-7 i

l

s 2.7.4 Immersion - Fissile Packages.

2-7 2.7.5 Immersion - All Packages.

2-7 2.7.6 Summary of Damago 2-7 2.8 Special Form 2-8 2.9 Fuel Rods.

2-8 2.10 Appendix 2-8 3.0 THERMAL EVALUATION 3.1 Discusrion 3-1 3.2 Summary of Thermal Proporties of Materials 3-1 3.3 Technical Specifications of Components 3-1 3.4 Thermal Evaluation from Normal Conditions of Transport.

3-1 3.4.1 Thermal Model 3-1 3.4.2 Maximum Temperatures.

3-1 3.4.3 Minimum Temperatures.

3-2 3.4.4 Maximum Pressure.

3-2 3.4.5 Maximum Thermal Stresses.

3-2 3.4.6 Evaluation of Package Performance for Normal Conditions of Transport 3-2 3.5 Hypothetical Accident Thermal Evaluation 3-2 3.5.1 Thermal Model 3-2 l

3.5.2 Package Condition and Environment.

3-2 e

3.5.3 Package Temperatures 3-3 3.5.4 Maximum Pressure 3-3 3.5.5 Maximum Thermal Strossos 3-3 3.5.6 Evaluation of Package Performan for Hypothetical Accident Thermal conditions 3-3 3.6 Appendix 3-3 l

4.0 CONTAINMENT 4.1 Containment Boundary 4-1 4.1.1 Containment Vessel.

4-1 4.1.2 Containment Ponotrations.

4-1 4.1.3 Seals and Wolds 4-1 4.1.4 Closure 4-1 4.2 Requirements for Normal Conditions of Transport.

4-1 4.2.1 Containment of Radioactive Material 4-1 4.2.2 Pressurization of Contair.mont Vessel 4-2 4.2.3 Containment Criteria 4-2 4.3 Containment Requirements for Hypothetical Accident Conditions

. 4-2 4.3.1 Fission Gas Products 4-2 4.3.2 Containment of Radioactive Material 4-2 4.3.3 Containment Criteria 4-2 4.4 Special Requirements 4-2 4.5 Appendix.

.4-2 11 1

4 5,0 SHIELDING EVALUATICA 5.1 Discussion and Results 5-1 5.2 Source Specification 5-1 5.3 Model Specification.

5-1 5.4 Shielding Evaluation 5-1 5.5 Appendix 5-1

6.0 CRITICALITY EVALUATION

6.1 Discussion and Results 6-1 6.2 Package Fuel Loading 6-1 6.3 Model Specification.

6-2 6.3.1 Description of Calculational Method.

6-2 6.3.2 Package Regional Densities 6-3 6.3.2.1 Fuel Region 6-3 6.3.2.2 Fuel Box Region 6-3 6.3.2.3 Reflector and Moderator Regions 6-4 6.4 Criticality Calculation.

6-6 6.4.1 Calculational Method 6-6 6.4.2 Optimization 6-6 6.4.3 Criticality Results.

6-7 6.5 Critical Benchmark Calculations 6-7 6.5.1 Benchmark Experiments.

6-7 6.5.2 Benchmark Calculations 6-8 6.5.3 Results of Benchmark Calculations.

6-8 6.6 Appendix 6-9 j

6.6.1 Fuel Loading Optimization.

6-9 6.6.1.1 Discussion and Results.

. 6-9

'6 6.1.2 Package Fuel Loading.

6-10 6.6.1.3 Model Specification 6-10 4

6.6.1.3.1 Plate Geometry 6-10 6.6.1.3.2 Homogenized Geometry 6-11 6.6.1.3.3 Regional Densities 6-12 6.6.1.3.3.1 Plate Model 6-12 6.6.1.3.3.2 Homogenized Model 6-12 6.6.2 Interspersed Moderations Optimization.

6-15 6.6.2.1 Discussion and Results.

6-15 6.6.2.2 Package Fuel Loading.

6-15 6.6.2.3 Model Specification 6-15 6.6.2.3.1 Model Geometry 6-15 6.6.2.3.2 Package Regional Densities 6-15 6.6.2.3.2.1 Fuel Region Densities 6-16 6.6.2.3.2.2 Fuel Box Densities.

6-16 6.6.2.3.2.3 Moderator Densities 6-16 6.6.2.4 Criticality Calculations.

6-16 6.6.2.4.1 Calculational Method.

6-16 6.6.2.4.2 Optimization.

6-16 6.6.2.4.3 Optimization Results.

6-17 111

I o

i l

7.0 OPERATING PROCEDURES 1

7.1 Procedures for Loading the NNFD-SA-2

. 7-1 7.2 Procedures for Unloading Package 7-2 7.3 Preparation of Empty Package for Transport 7-3 7.4 Appendix 7-3

)

8.0 ACCEPTANCE TESTS AND MAINTENANCE PROGRAM I

8.1 Acceptance Tests 8-1 8.1.1 Visual Inspection.

8-1 8.1.2 Structural and Pressure Tests.

8-1 8.1.3 Leak Tests 8-1 8.1.4 Component Tests.

8-1 8.1.5 Tests for Shielding Integrity.

8-1 8.1.6 Thermal Acceptance Tests 8-1 8.2 Maintenance Program.

8-1 9.0 REFERENCE 8 9-1 i

1 iv

r l

i LIST OF TABLES I

i i

Page Table 1.1 NNFD-SA-2 Shipping Container Attributes 1-3 i

(

Table 6.1 Characteristics of Design Basis Fuel.

6-2 Table 6.2 Measured Versus Calculated Values of X,g 6-20 Table 6.3 Average KENOIV-to-Measured Differences.

6-21 l

Table 6.4 Comparison of KENOIV Calculations with l

Measured Data 6-22 i

Table 6.5 Data General KENOIV-to-Measured Differences 6-23 i

I.

i l

l

- i i

h a

c 4

V I

+l

,. ~.,. -, - -, - -

w---

--n-x

--v-

LIST OF FIGURES Page Figure 1.1 NNFD-SA-2 Shipping Container Sketch 1-4 Figure 1.2 Shipping Container Inner Box Sketch 1-5 Figure 1.3 NNFD-SA-2 Shipping Container Birdcage Assembly.

1-6 Figure 1.4 Inner Box (102") for NNFD-SA-2 (Sheet 1 of 2) 1-7 Figure 1.5 Inner Box (102") for NNFD-SA-2 (Sheet 2 of 2) 1-8 I

l Figure 1.6 Inner Box (72") for NNFD-SA-2 (Sheet 1 of 2) 1-9 Figure 1.7 Inner Box (72") for NNFD-SA-2 (Sheet 2 of 2) 1-10 Figure 2.1 Shipping Container Test Model Sketch.

2-9 Figure 6.1 Array Model for Criticality Analysis.

6-5 Figure 6.2 Sketches of Fuel Region-Optimization Models 6 -Figure 6.3 KENO Input Listing for Staggered 12 Plate Model 6-14 Figure 6.4 KENO Input for Homogenized Array Model.

6-19 t

i vi 7

1.

GENERAL INFORMATION 1.1 Introduction The model NNFD-SA-2 Shipping Container design has been evaluated by the Babcock & Wilcox Company.

The container is used as a Fissile Class III container for the shipment of U-235 onriched uranium fuel elements. The fuel elements consisting of a sintered uranium oxide core with bonded Zircaloy cladding.

This document demonstratec that the model NNFD-SA-2 container complies wi+.h the requirements

" Packaging and Trans portation of Radioactive of 10 CFR 71 Material", including the results of testLng and evaluations needed for qualification of containers in which fissile materials are transported.

The purpose c'

this report is to consolidate the supporting documentation and to present the ovaluations in a format consistent with Regulatory Guide 7.9.

The results of this evaluation show I

that the container complies with the applicable regulations.

1.2 Packaoe Descrintion 1.2.1 Packaaina l

The NNFD-SA-2 container (Figuro 1.1) consists of a steel frame and a fuel container centered within the framo.

The maximum weight of the assembly is 520 pounds.

The steel frame will have outside dimensions of 2 feet by 2 foot by 12 feet in length.

The frame will be fabricated from slotted 3 inch x 1 1/2 inch x 0.104 inch thick steel angles fastened together with 3/8 inch steel bolts.

The fuel container will be centered in this frame with sections of slotted steel angle bolted directly against the six sides of the i

box.

The angles will form a stool framework around the inner box that functions as a fuel container.

The birdcage provides a geometric constraint to control the array spacing of adjacent containers.

The fuel elements are contained in an innor box (Figure 1.2) f abricated. from 14 gage mild stool with a maximum sectional area of 8.5 square inches.

The box has a hinged lid and uses a Neoprene gasket for an environmental seal.

Two box lengths are permitted; 96 inches and 102 inches.

Tho innor box is not a pressure vessel and is not designed to limit water in-leakage.

After mounting the inner box.in the steel frame, the additional lengths of angle will bo bolted in place to retain the box inside l

the birdcage frame, j

Coolants are not applicable and there are no heat dissipation l

requirements (since the contents are not irradiated).

No shielding, noutron absorbers, moderators, or pressure-relief systems are employed in the design.

1-1

1.2.2 Operational Features 1.2.3 contents of Packaaina The model NNFD-SA-2 container will carry Zircaloy clad fuel elements.

Within the cladding, the Special Nuclear Material will be unirradiated uranium enriched in the U-235 isotope.

The dimensions of the elements for transport will be approximately 0.090 inches x 3.5 inches x 96 inches long.

The maximum contents of each package will not exceed 240 lbs. and the U-235 content will not exceed 4 kilograms.

No heat buildup, pressure buildup, or cooling requirements were considered since the contents are unirradiated.

The minimal activity level of the shipments negates the need for any shielding.

1.3 ADpendix None Applicable.

i L

1' 1-2 l

7 g

,y

TABLE 1.1 NNFD-SA-2 Shipping Container Attributes Package ID USA /5910/B( )F Fissile Class III Package Configuration A Steel Inner Box within a Steel Birdcage Frame Gross Package Weight 550 Pounds Overall Dimensions

-- Birdcage Frame 2 Ft x 2 Ft x 12 Ft long

-- Inner Box - 102" 1.625 in. x 5 in. x 102 in.

long

-- Inner Box - 72" 1.625 in. x 5 in. x 72 in.

long Capacity 240 Pounds with a Maximum of 4.0 kg of U-235 Contents Unirradiated Fuel Elements Enriched to any degree in the U-235 isotope L

1-3 h

,..,e.A_4_.h.%Aa,a.__d_,_ga6--*=.Mhsawam-Med*-4 4 ee-4"*+----54 em~ha#-

-da*'M^^-^4-e M e#**^*'*-ud'

1. 1. '#*h^

^*#

-" * --*-'-'"~*-

4 N

3

/s

/

t n

t

.h i

~~

uh

!j f.

7 8

E h

z

~

~N g

8$

m i

1-4 1

1 i

~. _.. _ _

o O

S

-e-w

.C U

4J 0)X to X

k e4 wed z.e u

G C

C H

u (D

C b

• e4 (U

4J C

OU tT.

C

• -4 b

k cL

• e1

.C La o

i N

N Q) -

W

$tn

• a

$Le 1-5

F

.a l

.l l

I

}

i

• ~ - -

i es d

L

... we. i. x -

u.m...=---

a....

pA p2

,, ox.. w _

L i e. oo.. no -.

,, wo..,,o c.1 I.l q,

f i 1 I

I l

l

.a -

-s

-1 u

__t 1 - -.

,._____J.

4:

/

n L

+

4A 42

.e..

h NNFO-SA-2 SHIPPING CONTAINER 8

a.. Co. 50 2

w,, w..w a

_c/

I

c. 7 7,

y.,

e

/

<+

j t

i.

.s_

l j'..

".l.l - * *h

.- p.

l-

,0-1 1

c.y 7.-

c.

v --

4 x s'

-_____t._,

l l

g VIEW A-A SECTION 2-2 a

i a

i i

i i

,4 a.

i i

=

i i

i i

i St APERTt!L CARD p

Also Available 01.

Aperture Card

. u.ow...oo a

.iu, -,.i.<

1

- I-g,

,gg

3

_iro, n t" Ele" -.

pJ:t

. '*9' '

% iro,n artMn ~.

EJC

(

.ro,,,se n.v:'m -,

m*Ie

)

6.!%. -

WJ;6 e %

j ero,e,ie[ M,.s.. ~,

/i i _ /____..

/

f WZ4N sto,u,e s_.

~~~

e s iro,.is M 7.'".

Fll%

i t

i ro,i n t Y,*if.h!.

sten 11 %

frovelet Ba@

h_

_/ /

/-_ !I m.

~

1. taATUtt ALs ELOffED AMELt lacre.

'"'"'' Mi@'P%fTJ. w m BIROCAGE ASSEMBLY

+

Esft,#'3,48:5Dl%*.bbt'"l

g%I%'.';it? '.?f; t%MW'a-8 4

4

-- = =r, e.-

I m ' a n %9 a: ~15.2 %

..I L

_L.,,..-,.,,-..

.,=J g

Figure 1.3 NNFD-SA-2 Shipping Container Birdcage SECTION X-X Assembly W'lbI Ech2*?."2 IriE.,,S..F..T.

W m,

e 1 2071iIE 8

~..

I l-6 i

1 1

I a

i l

- = =

PbC2.90330 -O/

\\

t I

e I

e I

i

.m l l

1 il 3

et

,x,x x,x,x,x

- x,3,x,x

,x,

,x

,x,x,x

, x,x,x x

x x x x x

/

1 s

.i

/

q

(

s

/

r' s

l P

2 1

7 1

1 1

1 1

1 1

1 1

1 1

1 7

7 1

1 7

1 1 1 1,

P 9.00 $N$l06 $0E D3a4 4 10 4 BOX CROSS SECTION (TYPICAL)

+

e 3

/

p t xr xa xa x x xr xr x x xr xr xr x x xr s xr x x xr xr xE'x x x -

r s

/

N s

i. ore mar l

1 1

7 7

7 7

1 1

7 7

1 7

7 1

1 1

1 7

7 1 1

1 7

7 1

7 7

7 7

r r r r 1

I e

iO2' 1NB10E 80s DIWN510N

~

INNER BOX SIDE SECTIO e

a

'e. Y k. w is j.

is i

n i

l 3

e i

e

i i

i i

1 I

l S1 APEltTUlt E CARD j

l dl$Jd%D$\\*I)!Ok)'

d Aliei tiiit C.rtr(i J

k

~

4 DILL OP nanttmtAL q

r m.-

==.

ames.

.s 1

tF078 t M twem hos atesagm V (102'I e

/

ta I

i t 707I tM 90s bottas STttL 7

1 a poit 1M SON Ltp BTttt 8

I F09 9 t M 40Pete tatyt?

NOTE F 4

4 1907 8 t N 6&AW D1fv tur attsseLY STREL

=

d 9

9 1701t IN ant.twe plass-etAW ELirv STitt

@ ftte

1. tanftmlALs le Sam ti!LD StatL Dett 3700t,

..,.;yie.ag.e. GA.n 9.n

.T.

3. gt{

genAY St ATTAGED TO T4 EPO

4. gtgNEtt ApO HAFS Amt 70 St

~

l S. ENTing p/ fan SMAct TO 98 PAINTED ItuY.

4-a i

PIt?.*. a5'&omb'"i!.WEboA i

~ ~ ~ ~ ~ ~

i s

.. 0 mu l

s

<s-o 1

1

/

/.

C f

4 Figure 1.4 Inner Box (102") for NNFD-SA-?

i (Sheet 1 of 2) 90/0290330 -0e

~

!W BOX 102*)

,7 '.. ".T. * *."".

-e FCR P4#0 5 -2

.-==.a

• e

. =

lt$.'.T *

• • '.*'"J.'*"***

.. bd_

SHIPP]NO

• E' CCNTA{NEA SPEET I 0F 2 sa l

l t207112E i

t t

a 1

i i

a i

i

~~

4 17

i i

i i

.el.. i i

9 l

r-te

@ LID-FRONT VIEW iu.oo -

P l

l I

I i

r..

i I

i i

j i

BOTTOM BACK SIDE VIEW ion.co

+

t e

STCTION Z-Z - CROSS SECTION tktba%Mit!,'oa-f umuo.,

l E

I t.

@ BOTTOM-FRONT VIEW u

.1siiEs ~

(.ow,

j /.A q

l

..o30 TYP DETAIL - A i

l-

'a i

=

i i.

i 4,_.

i i

i i

t i

y....

gi T

APERTURE

~

CARD i

_ f,','

Also Available On Aperture Card s.=

1

.ove e

~ l'AM&N.i'2Es

~ ~ ' ' ' '

i

.on

~.o79 4

I I

.o7e SEE DETalL.a Qg l

SEE DEtalb-a h

sam h _. _ _

l V

I are - Z Z

r.

2. -

9.156 W 1;

l PEi'A! !'. 7JhoE % : m i = 4 pi Figure:1.5 Inner Box (102") for NNFD-SA-2 (Sheet 2 of 2)

.o m g;

M E" * ('02")

.=:.v:-:::n

-. w--

tw o - sa 2

E-3E'E.*

SHIPPING CONTAINER

~~~

SHEET 2 OF 2 3:

p 1207112El i

-i i

a i

a i

,__1 4

i 90/0290330 -03

+

• 8 I is l it I

n I

i e

e l

l

~ ~ -

i..

1 es e

t e

N

,x x

x x,x,x x,x x x x

,x,.,x

,x,1,1 x,x,x x x x

s N

/

(P /'

(

/

a,

/

/

/

9 i

1 1

1 1

1 1

1 1

1 1

1 1

1 1

1 1

1 1 1 1

- /.

1 1 1 eum 9.00 IN$t0E DOM OltE % IONS BOX CROSS SECTION (TYPICAL)

+

s 3

,.o

/

l} } }

11111111

'1I11;

/

/

~

//

/

3

/

4.87S M?

/

c

/

/

,/

1 1

1 1

1

, 7 1

1 1

1 1

1 1

1 1

1 1

1 1

,,,1 1

1 1

/

?L IN6t0E Sox O! WEN 510N INNER BOX SIDE SECTION M

i a

i

'a i

a i

i i

i

- 4

l' o

i l

I I

a e

c..

. ~.

SI APERTURE CARD t

/

Also Available On Aperture Card 81LL al' anATEnt AL

__r w s nc iA

=

I 2071 i W !*e4A tom ASSEneLv (T2*)

e 1

8 12071 ( M BON GOTT(ks tfEEL 2

6 120711 M 90N LIO STEEL 3

% 1207 t l M

• EasastENE &aarET NOTE 2 e

4 12o711M.aAvv Duty say Asunety STEEL 9

6 120?l l M eutt tvut Miums..sAvv euvv STEla.

PCTE$s I. tanTERI ale le GAM tilLD STEEL SEET 5700(.

3. esgA{aLeg SAMKET 94ET 5T00(

3. p lNat gasAY M ATTA04D TO T4 EPC

4. g (MyNSES AND HAPS AM TO M

~

S. ENTIRE QUf5R SAE' ACE TO M PAINTED GRAY.

Y a

~

e

./

1 1 ', ' ' 1 WP 8

l N

.540 fetr P N i} & W 2 8 0) M b.c'o*u %

~

/

C

.___1 1

7 7

7 7 Figure 1.6 Inner Box (72") for NNFD-SA-2 (Sheet 1 of 2)

..,, coo z w n sou

.~'_.2.~.~".

'su%%s'g72-)

' ~.~. E*W '

w w G

CONTA! HEM y

!>4EET I QF 2 1207113E l

1-9_

q e

i i

a i

i i

90/0290330 4

.m l

i. i i

i i

i i

l

@ LID-FRONT VIEW M

-nw P

~!$nid3J Sif!1s1 I

I l

(

I I

i i

i BOTTOM-BACK SIDE VIEW n.w -

4 SECTION Z-Z - CROSS SECTION o

J.06 7v*

--- rgg* gpajrgren i-h BOTTOM-FRONT VIEW C

a S CES 1

b 9

/r TYP d }

n.03:

DETAI a

a i

i i

.i o.

%# Nayd i

+'

i i

i i

i i

~.

~. f>40 arp g)

APERTURE CARD

. a,. -r

+

[g

. o r.,,

I bo Available On

=

9.00

[

Aperture L., art

.ov..cr 6

r I

!1 l

L

[

r

.07 Mr

. 0 79 Mr 4*

j S.00

.079 Mr

$EE Otra!L -a 8

- 4.825 q,,

f W OLES g

su oce.it..

T'Yn

-I

.0i. arr -

Z Z

., r. --

5.156 E

ANV!l,ACQU jW C - ll.

.,- a.c.m v r

~

T,.

L Figure 1.7 Inner Box (72") for NNFD-SA-2 (Sheet 2 of 2)

,.A

.. Lecco INNER BOX (72*)

"" *" " " "" l FOR

?L1I;*=*=**E.* 3 i *

==

I*'.**=*="e*me*.'.Y *

-M' NNFQ $A-2 i

=*

SHIPPING CONTAINER M*A* "* * *

• SHEET 2 OF 2

{.

trovi ise_j i

4p t

i

-,-- - p 1-10 D

0

yy k l. $

?.-

2.

STRUCTURAL EVALUATION 2.1 Structural Desian 2.1.1 Discussion The. container consists of a steel frame and a fuel container centered within the frame.

The maximum weight of the assembly is 520 pounds.

The steel frame will have outside dimensions of 2 feet by 2 feet by 12 feet in length.

The frame will be fabricated from slotted 3 inch x 1 1/2 inch x 0.104 inch thick steel angles fastened together with 3/8 inch steel bolts.

The i'uel container will be centered in this frame with sections of slotted steel angle bolted directly against the six sides of the box.

The angles will form a steel framework around the inner box that functions as a fuel container.

The birdcage provides a geometric constraint to control the array spacing of adjacent containers.

The-fuel elements are contained in an inner box fabricated from 14 gage mild steel with a maximum cross sectional area of 8.5 square inches.

The box has a hinged lid and uses a Neoprene gasket for an environmental seal.

Two box lengths are permitted; 96 inches and 102 inches.

The inner box is not-a pressure vessel and is not designed to limit water in-

-_ leakage.

After mounting the inner box in.the steel

frame, the additional lengths of angle will be bolted-in place to retain the box inside the birdcage frame.

- 2.1.2 Desian Criteria v

2.2 Weichts and Center of Gravity

'Loadeddfor shipment,-the NNFD-SA-2 container 'has a maximum 1 weight of 540 pounds.

This' includes!the maximum payload of-

240 pounds.

The container is symmetrical in design.

Therefore, the' center-

'of gravity will be at or very near the. geometric center of the

-rectangular container.

g 2.3 Mechanical Properties of' Materials.

v.

O Standard commercial materials are used in the construction of

'the NNFD-SA-2 shipping container.

.The primary material for the contai.ner.is carbon steel, either as slotted angle iron or-

?,M '

14. gage sheet stock.

Neoprene is used as the gasket material 4..'

for. the inner box.

The materials list is shown on the.

4 N ['

container drawings, Figures 1.3, 1.4 and 1.6.

u-2,

j I t f..

,,.N ' n'j !

',,('

{

p s 4'

...... ".5'.....

2.4 General Standards for All Packaoes 2.4.1 Minimum Packace Size The minimum overall dimension of the container is at each end, which is 24" x 24".

2.4.2 Tamoer Proof Feature Taper proof seals are located at several strategic locations on the package in order to prevent tampering.

2.4.3 Positive Closure The design incorporates provisions for padlocks and hasps to provide a

positive closure that cannot be opened unintentionally.

After the inner box is loaded, the box is banded with 0.75 inch-wide steel bands for positive closure.

2.4.4 Chemical and Galvanic Corrosion The materials of' construction (mostly painted carbon steel, L

steel bolts and Neoprene gasket) will not exhibit significant chemical, galvanic,-or other reactions between the container parts or with the Zircaloy clad payload and polyethylene packing: material.. NNFD-SA-2 containers have been used for more than; twenty years with no problems with unacceptable-levels of corrosion.

2.5 Lifting and-Tiedown Standards for All Packaces 2.5.1 Liftino Devices Lifting. devices.are'not provided on the NNFD-SA-2 container.

L The container is lifted from the bottom by a fork lift truck.

l This container has been successfully. handled in this manner.

i for overt 20. years.

.i 2.5.2 Tiedown Devices

}

L No tiedown devices.are' incorporated into the packaging.

The-l ltiedown system is part of the transporter.

L

' 2 '. 6 ' Normal-Conditions of Transoort~

1

.The.information provided in this section demonstrates-i complianceiof-v.he NNFD-SA-2 container with the requirements.

L

_ for ' the normal conditions of transport as-specified in 10CFR71.;

.Each condition is assessed separately. and, a-

' determination 'iu presented that the container design satisfied

.the applicable requirement. Where appropriate, references-are.

2-2 L

made to the licensing testing performed on the NNFD-SA-2 container.

2.6.1 linAt For the normal condition heat test for transport per 10CFR71 regulations, the package is to be subjected to an ambient temperature of 38'C (100'F).

Insolation requirements are also stated.

The specified increases in temperature and insolation input would not be of any consequence to the " birdcage" construction.

Likewise, the payload container would not be affected significantly by the temperature increase or the heat input rate because of the thin wsil construction.

Heatup of the payload itself (fuel platen) is also not of consequence, since they are designed for high temperature operation and significantly more rapid temperature changes.

In addition, there is no internal heat source since the payload contains unirradiated uranium.

2.6.1.1 Summary of Pressures and Temocratures Pressures are of no consequence since the container is not a pressure vessel.

The effects of the required temperature range (-40'C to +38'C) is of no consequence.

No liquids are involved in the materials used in construction.

2.6.1.2 Differential Thermal Expansion Within the temperature range specified (-40'C to +38'C) and considering insolation, the clearances and materials of construction do not present a

differential thermal expansion problem. Therefore, differential expansions were not computed.

2. 6.1 '. 3 -Stress Calculations The container has been successfully used for over 20 years.

'Although stress computations are not available, the history

.of usage speaks for the structural ' integrity _ of' the container, 2.6.1.4 Comoarison with Allowable Stress Not available, as stated above.

2. 6'. 2 fdtlsi

.The'affects of exposure to a steady-state-temperature =of -40'C

(-40'F) ' were considered as required.

The mild _ steel used in

. constructing ~the' container is not subject to brittle fracture

.at'this temperature.

U 2-3

(

m.

T 2.6.3 Reduced External Pressure The shipping container (inner box) is not a pressure retaining 12

. ' boundary.

No additional stresses would be imposed by a reduced external pressure.

T 2.6.4 Increased External Pressure The shipping container (inner box) is not a pressure retaining boundary.

No additional stresses would be imposed by a increased external pressure.

2.6.5 Vibration It is required to assess the container for the effects of vibration.

While no quantitative analysis has boon performed, the container has had a long history of successful use.

The physical inspections required prior to each use also provide assurance that-the container is in proper condition.

The i

design.is inherently

sturdy, is a

geometrically simple structure, and is not heavily loaded.

Considering the inspection requirements, design, and other test loading.that were required to qualify the container, any vibration that would be experienced during transport would be inconsequential i

to the required functional integrity.

2.6.6 Water Sorav A' water. spray test. was - performed as a part of the initial qualification of the container design.

The container was exposed to.the spray for 30 minutes..No water was found in the container following exposure to the spray.-

considering i

the design, there is no reason to believe that a longer period of exposure or a higher flow rate of spray would.have made any difference in test >results.

2 '. 6. 7J Free DroD' A dropftest was performed from a height of 4: feet as'requ' ired.

~

. The.'. test:was.' conducted such that the impact was to-the long horizontal edge of.the. container frame..-The: test is described as.having negligible'effect on the container.

The drop test.

was notl performed within the:specified time interval following the waterLapray test'.

However, the materials of construction and the. container: design are such that the' water spray. test

~would not have any effect on the results of this drop test.

2.6.8 : Corner Droo Not applicable.

(Only required for fiberboard or wood packages).

2-4 J

,I

.s.

4 2.6.9 Comoression For the test conducted, the container weight was 163 pounds.

The compression test load was 3633 pounds for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

For the-vertically projected area of the test model, 1728 ina (2 ft. x 6f t. ), the required load would be the greater of 1066

- pounds or five times the weight of the package (815 pounds).

Thus, the test, as performed, exceeded current requirements by approximately a factor of three.

Test results were satisfactory, there were no discernable affects on the package after the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test.

2.6.10 Penetration

'A penetration test was performed in 1965 using a steel cylinder weighing 12 pounds rather than the currently required 13 pounds.

However, the drop was made from a height of 4 ft.

-(48 inches) rather than the current 40 inches or one meter.

The added kinetic energy of the cylinder when dropped from 8 inches greater height should compensate for the slightly lower weight of.the cylinder.

The impact was. to the center payload container box and resulted in no penetration of the box.

This result is considered:a satisfactory demonstration that the package is resistant to penetration.

2.7 Hvoothetical Accident Conditions 2 7.1 Free Droo

. A - free - drop - test from a height of 30 feet - (9 meters) was performed on a shortened-prototype container.

See Figure 2.3.

This. test ' container accurately represents a

full length container during the~ drop test.

-2.~7.1.1

-End Dron A prototype container was allowed to free fall from a height of 30 feet.(9 meters) on to a concrete pad.

The container-was oriented so that the impact was on the end of the: container.

'An. inspection of the container after-the drop revealed no

.significant damage to the container.

There was no loss of material. from the inner box. -The position of the inner' box -

within the' birdcage remained unchanged.

'2.7.1.2 Side Droo Not '. Applicable.

The end drop was determined to be the bounding. case for damage to the container.

4 l

2-5

c.

-2.7.1.3 Corner Droo Not Applicable.

The end drop was determined to be the bounding case for damage to the container.

2.7.1.4 Obliaue Drop _g Not Applicable.

The end drop was determined to be the bounding case for damage to the container.

2.7.1.5 Summary of Results There was no significant damage to the NNFD-SA-2 container as the result of the free fall test.

The test did not impair the ability'of the NNPD-SA-2 container to contain the radioactive material in the inner box.

2.7.2 Puncture The puncture test was performed by dropping the prototype container on a 6 inch diameter post from a height of 40 inches (1 meter).

Impact was on the long axial side of the birdcage frame.

The drop height was measured from the bottom of the birdcage to the top of the post.

The post was 8 inches long with a 6 inch diameter.

A visual inspection of the container was made after the puncture drop.

There was a slight distortion of the angle iron frame at the point of impact.

This deformation did not affect the ability.of-the container to contain the inner box and to maintain the spacing with adjacent containers.

There was no damage to the inner box.

2.7.3 Thermal A thermal test was'not performed on the NNFD-SA-2 container.

. The' evaluation of ' the container is based on its physical

. dimensions and the - high melting point of the materials of construction..

2.7.3.1

-Summary of' Pressures and Temperatures ThereLare no significant pressure differentials acting on the container structure since -in inner box: is not- ?

pressure boundary.

Y

'Due to the thin wall construction, there are no'significant temperature gradients in the container structure.

-u:

L 7. 3. 2' Differential Thermal Exnansion s

As' discussed in Section 3, both the inner box and the bird cage outer structure are made from steel and would exhibit similar. thermal expansions.

The relatively thin wall-(14 6-n

i 4

gage).; sheet stock used in the fabrication of the inner box would not develop any significant thermal gradient or associated stresses during the fire accident transient.

A similar case can be made for the angle iron birdcage structure.

2.7.3.3 Stress Calculations There are no significant thermal stresses induced in the container structure as the result of thermal gradients or differential thermal expansion.

This is applicable to both normal operating conditions or the consequence of a hypothetical fire accident event.

2.7.3.4 Comoarison with Allowable Stresses Not Applicable.

No stress analysis was performed on the NNFD-SA-2 container.

Compliance with the design requirements was demonstrated by testing.

' 2.7.4-Immersion - Fissile Material Not Applicable.

Water in-leakage was assumed in the

- criticality-analysis for the accident cases, therefore, this test'is not. required.

2.7.5 Immersion - All Packaces

'I The regulations are'that an undamaged container be subjected to a water-pressure equivalent to immersion under a head of L

water of at least 50' feet (15 meters) for a period of not less thanreight hours.

An external-pressure of 21 psi (147

~

kilopascals) is considered equivalent to the immersion test.

j i

Thecinner1 box of'the NNFD-SA-2' container is not designed to o

. limit water-in-leakage. The thin wall construction used for.

the: inner boxL with -its high cross-section to length-ratio precludes a leaktight containment.

The inner box gasket acts

~

onlylas-an environmental. seal against a water spray.. Water s.

in-leakage prevents any significant pressure differential from a

developing across the box walls.

In a " worst case" scenario,

?

the inner box'could be' deformed, but due to the large physical size.of" the fuel L elements, there would be no dispersal of.

radioactive material.

i The immersion test would not have any effect on the birdcage structure due to its open: construction.

o 2.7.6 Summarv of Damagg The. hypothetical accident conditions do not have a significant i

impact,.on :the integrity-of-the NNFD-SA-2 container or. Its

' ability ~to contain the radioactive material.

A thirty foot-

~

free. drop and a puncture - test was performed on a sample g

container with only minor damage to the container.

The fire

(

2-7

)

i s

-l 1

I.

t test and immersion conditions were determined not to have a-significant effect on the container.

2.8 Spscial Form Not. Applicable.

2.9 Fuel Rods Not Applicable.

As discussed in Chapter 4, the fuel element cladding is not considered as the containment boundary.

The cladding functions only as environmental boundary to protect the uranium core material.

2.10 Annendix None Applicable, i

2-8

u e

~

i' Cont,,"*E Tegy Mode 3 sketch 4

El9tive 2 2 shiPP1n9 i

i i

d 0 e

n e

.j s

s e j

t,

..A1.

e 8 *3 e

O i

2

.s o

g b

e f

o G*#

~

l e

._f#..

A I

6 l

e W

l i

2 l

0 is i

O 6'

i l

gt te.

k l

l l

i i

f t

i l

~r

l 3.

THERMAL EVALUATION 3.1 Discussion The-Zircaloy cladding ~of the un-irradiated fuel elements is not considered to provide the containment boundary of the enriched uranium material shipped in the NNFD-SA-2 container.

Confinement of the uranium material is provided by the inner container box. A fuel element coasists of a solid uranium oxide core clad with a layer of Zircaloy 2 bonded to the core material.

Dimensionally, the fuel elements are approximately 3.5 inches wide by 96 inches '.ong with a thickness 0.090 inches.

No powder or liquid As shipped in the container.

There is no decay heat associated with the container contents.

3.2 Summary of Thermal Properties of Materials The materials of construction of the NNFD-SA-2 shipping containers are standard materials with well documented thermal characteristics.

The open bird cage is fabricated from mild steel slotted angle iron.

The inner box is fabricated from 14 gage steel sheet stock, and provides confinement of the nuclear material.

The thermal properties for the materials of construction are not required =since no thermal analysis was performed.

All materials have a melting point well above the temperatures expected for the conditions of normal transport and during the hypothetical fire accident.

3.3 Thermal Specifications of Components

'None Applicable.

3.4 Thermal Evaluation for Normal Conditions of Transoort The NNFD-SA-2 container meets the' requirements for the normal conditions of transport.

The container contents do not generate heat and there is no pressure containing-boundary in y

the'NNFD-SA-2 container.- 'There is no credible failure mode for the NNFD-SA-2 container. for the normal condition of transport.

3.4.1 Thermal'Model J

Not Applicable.

3.4.2 Maximum-Temoeratures There is'no indication that a temperature increase above the 1

1 ambient (100 F-for the normal conditions of transport) would-Fresult in a loss of function for the container or its components.

[

l 3-1

\\

h

3.4.3 Minimum Temoerature The minimum temperature for the container is the ambient

' temperature associated with the normal conditions of transport 40 'F) since there is no decay heat from the container L(

contents.

An empty container would experience the same temperature range as a loaded container.

3.4.4 Maximum Pressure The gasketed inner box that contains the fuel elements is not pressurized.

The gasket functions as en environmental barrier to protect the fuel elements from water, dirt and other contaminants.

Any pressure due to the thermal expansion of the air inside of the box would be relieved by air leakage from the box.

Due to the physical dimensions of the-box, a small deflection of the box ar.d/or lid would quickly relieve any pressure differential without any permanent deformation of the structure.

3.4.5 Maximum Thermal Stresses The are no significant thermal stresses generated within.the NNFD-SA-2 container or its contents.

Adequate clearances are r

.provided between components to accommodate thermal expansion.

3.4.6 Evaluation of Packace Performance for Normal Conditions of Transnort-t The NNFD-SA-2 container will perform -as intended for all-normal conditions of. transport.

3.5 Hvoothetical' Accident Thermal Evaluation

.The NNFD-SA-2 cont'ainer meets the requirements - for normal conditions of transport.

The container contents 'do not

' generate-heat andithere is no pressure containing boundary in the NNFD-SA-2 container.

3.5.1 Thermal Model Not Applicable.

No thermal analysis'was performed.

L 3.5.2 Packace Condition and Environment

. There-wasino'significant damage to the NNFD-SA-2 container as go the result of the free' drop and puncture tests.

An undamaged container is1the limiting case in considering the effect of l

the fire accident.

3-2 r

i

,4

3. 5. 3 -

PAckaae Temoeratures The maximum temperature that the NNFD-SA-2 would experience during the regulatory fire accident is approximately 1500 'F, the temperature sf the fire.

3.5.4 Maximum Pressure The.'gasketed inner box that contains the fuel elements is not

' pressurized.- The gasket functions as an environmental barrier to protect the fuel elements from water, dirt and other contaminants.

As is the case for the normal conditions of transport, any pressure due to the thermal expansion of the air iaside of the box would be relived by air leakage from the box.

Due to the physical. dimension of - the box, a small deflection of the box and/or lid would quickly relive any pressure differential without any permanent deformation of the structure.

3.5.5 Maximum Thermal Stresses s

The are no significant thermal stresses generated within the NNFD-SA-2 container or its contents.

Both.the inner box and the birdcage outer structure are made from steel and would exhibit similar thermal expansions.

The-relatively.ithin wall (14 gage) sheet stock used in ~ the fabrication'of the inner box would not develop.any significant thermal ' gradient or associated stresses during the fire accident transient.

A similar caso can be made for the angle iron. birdcage:-structure.

l 3.5.6 Evaluation of Packace Performance for Hvoothetical

. Accident Thermal Conditions During a hypothetical-fire accident, the. temperature of the container 'and contents would be approximately'1500 F, the fire

' temperature.

The NNFD-SA-2 is a all metal container with the exception of the Neoprene gasket.

The melting temperatures of theimetals is greater than the temperature experienced during-the' fire.

.No structural degradation is expected as a result of - the l fire.-

Both the ' container structure and-the fuel element would survive a - fire accident ' impact.- The. inner box gasket ~would be degraded during.the fire.

Since the gasket is not>part of the containment boundary, loss of the gasket is an acceptable-consequence:of;the fire.

Based on this scenario,

. there; would be"no: dispersal of the radioactive contents from j

the' container'as the result of the fire accident.

3.GApnendix None Applicable.'

d.

3-3

^

.i L

4.

CONTAINMENT 4.1 Containment Boundary Containment of the contents. of the NNFD-SA-2 shipping container is based on the principle of confinement of the radioactive material.

The container prevents the dispersal of large pieces of radioactive material.

The relatively large size and solid construction of the fuel elements shipped in the 'NNFD-SA-2 container preclude any concern for small particulate or gaseous leakage.- No gases,-powder or liquids are permitted to be shipped in the NNFD-SA-2.

r Dimensionally, the large size of the fuel elements (3.5 inches x 96 inches long. With a 0.090 inch thickness) limits the

-possible mode for dispersal of any radioactive material.

The Zircaloy 2 clad is bonded to the core material.

This cladding provides a level of environmental protection for the uranium oxide core.

It also precludes the release of any fine particulate from the core material, i

4.1.1 Containment Vessel Not Applicable.

4.1.2 Containment Penetrations Not Applicable.

4~1.3 Seals and Wolds Not Applicable.

14 1.4 Closure Not Applicable.

4.2-Reauirements for Normal Conditions of Transoort'

4.2.1 Containment of Radioactive Material Containment of the-contents-of the NNFD-SA-2 shipping container isubased.on1the preventing the dispersal of large,

. pieces'of radioactive-material.

The'relatively-large-size and solid' construction of the fuel elements shipped in_the NNFD-SA-2 container preclude any concern forLsmall particulate or gaseous leakage.

No gases, powder or liquids are permitted to be shipped in the NNPD-SA-2.

4-1 41

?

9 4.2.2 Pressurization of Containment Vessel

~

Not Applicable.

The fuel element cladding is bonded directly to the core material.

4.2.3 Containment Criteria Not Applicable.

4.3 Containment Recuirements for Hyoothetical Accident Conditions 4.3.1 Fission Gas Products Not Applicable.

Only un-irradiated fuel elements are permitted to be shipped in the NNFD-SA-2 container.

4.3.2 ggntainment of Radioactive Material As'is the case for normal conditions of transport, containment of the contents of the NNFD-SA-2 shipping container is based on preventing _the dispersal of large pieces of radioactive material.

The relatively large size and solid construction of the fuel elements shipped in the NNFD-SA-2 container preclude any' concern.for 'small particulate or gaseous leakage.

No gases, powder or liquids are permitted to be shipped.in the NNFD-SA-2.

4.3.3 Containment criteria Not Applicable.

4.4 Special Recuirements Not Applicable.

4.5 Anoendix

.None Applicable.

h 1

i

('; '

u h

t'

), '

4-2 L

in

e 5.

SHIELDING EVALUATION 5.1 Discuscion and Results only unirradiated fuel elements are permitted to be shipped in the NNFD-SA-2 container, therefore the shielding concerns are minimal.

There are no design features specifically incorporated into the container design for the purpose of radiation shielding.

Radiation levels at the container boundary are measured as part of the shipping procedures.

These dose rates must be within-prescribed limits in order for the loaded container to be shipped.

5.2 Source Specification Not Applicable.

5.3 Model Specification i

Not Applicable.

5.4 Shieldina Evaluation o

Not Applicable.

5.5 Appendix None Applicable.

i 5-1

6.0 CRITICALITY EVALUATION

6.1 Discussion and Results The NNFD-SA-2 package is designed to contain unirradiated clad fuel elements with a maximum U-235 loading of 4 kilograms.

The fuel elements will measure approximately 0.2286 cm x 8.89 cm x 243.84 cm(0.09" 'x 3.5" x 96").

The maximum loading of any element will

- consist of 320 grams of U-235 in the form of sintered uranium oxide wafers.in a bonded Zircaloy-2 cladding.

Any enrichment of the U-235 isotope is allowed.

The fuel elements are contained in a 14 gauge steel box with a maximum cross sectional area of 53.84 2

a cm (8. 5 in ).

The fuel box is centered in a birdcage framework consisting of 0.264 cm(0.104") steel angles.

The nominal outside dimensions of the birdcage are 60.96 cm x 60.96 cm x 304.8 cm(2' by 2'

by 12').

This chapter illustrates-that the NNFD-SA-2 package meets the requirements of Sections 71.55 and 71.61 of 10 CFR Part j

71 for Fissile Class III shipment of nine(9) packages.

1 The analyses for this package used the KENO-IV Monte Carlo program with the 123 group XSDRN cross section setz.

An array of 36 packages was modeled with KENO box type geometry.

The package model consisted of the fuel box filled with a homogeneous mixture of -U-23 5 and water.

The 6-by-6 array contained optimal hydrogenous moderation and was closely reflected with water.

The analysis of this model yielded neutron multiplication values as follows:

h,,,

sigma h,

0.66320 0.00283 0.709 The-analysis shows that the design of the package has a neutron multiplication

factor, with correction for uncertainty and bias (k that.is significantly below 0.95.

The analyses -that derr.onsk)r, ate :

conformance to-this criterion were bounding and extremely.-ccnservative.

They include:'1) 4 kilograms of infinite

- dilute U-235~ homogeneously mixed with water at maximum density, 2) no,other fuel element material, i.e.

zirconium, oxygen, U-238, included in.the model, 3) fuel box steel at minimum thickness but-

- with maximum internal cross section area to increase the H/U ratio,

~

4) no ~ consideration of -the structural material of the birdcage framework, 5) array spacing based upon' minimal birdcage ' square

- dimensions, 6) evaluation of optimal interspersed moderation (about 5%: dense water), and 7) an optimal array configuration with twice the number of elements required for the normal condition evaluation -

.and four times the' accident condition evaluation.

ll 6.2-Packace Fuel Loadinc The NNFD-SA-2 package is designed to transport unirradiated, clad fuel elements. The characteristics of these elements are presented

'in Table 6.1.

6-1 s

e an,

TABLE 6.1 CHARACTERISTICS OF DESIGN BASIS FUEL Fuel element width-0.2286 cm(0.09 in.)

. Fuel element height 8.89 cm(3.5 in.)

Fuel element length 243.84 cm(96 in.)

Cladding material Zircaloy-2 Fuel. Wafer material Sintered Uranium Oxide Maximum Enrichment, U-235 100%

Maximum U-235 weight / element 320 grams Maximum.U-235 weight / package 4000 grams i

6.3 Model Specification

(

This section describes the model used in the criticality analysis.

The model represents an 6-by-6 array of packages under accident conditions.

This model will bound any actual shipment of packages for either normal or accident conditions.

6.3.1

' Description of Calculational Model L

Nine NNFD-SA-2-packages are to be shipped as Fissile Class III.

For this ' class of - shipment.10 CFR 71 - Sections 71.55 'and 71.61' require that-the shipment remain subcritical for the normal condition with twice'the number of packages closely reflected on-all sides ;by water, and for the accident condition with one.

L (shipment of - packages closely reflected by water with optimal interspersed moderation. The' calculational model' considers a 6-by-6 array of packages.

The package is represented as the fuel box filled.with a homogeneous mixture of. water and 4 kilograms of U-235. Optimized intersporsed moderation, about 5%, fills the region-between units of the-array which'is-surrounded by.a 45.72 cm(18")

l thick water -reflector. - A sketch of the model is provided in Figure 6.1.

The model provides a bounding analysis for both the normal and the accident conditions.

The package contains uranium oxide fuel-plates; clad with zircaloy-2. =Neither.the cladding nor the~ oxide material of the plates are" included in the analytical fuel model.

l The fuel is considered to be U-235 metal homogeneously mixed with-h the water moderator rather than assigned to a plate region.

In-L addition,' tolerances on the fuel box dimensions are included-to l

l

.6-2 i

t.

m

increase the inner volume of the box so as to increase the amount of moderator in the fuel region.

A minimal fuel box wall thickness is used to reduce absorption in the walls.

The array contains only the fuel box material without the structural members of the birdcage.

The fuel boxes are placed on a 59.69 cm(23.5") center-to-center spacing in the array.

This represents the minimal dimensions of the birdcago and hence, the smallest array spacing.

The discussion contained in Section 2 indicates that under normal or accident conditions no significant damage occurs to the birdcage or the fuel box.

Any bowing or twisting of the birdcage due to the accident will only serve to increase the inter-package spacing, lending conservatism to the analysis.

The array case for zero density interspersed moderation, as discussed in section 6.6.2, essentially represents the conditions required for the normal condition analysis.

Thus, the array model proves a conservative model for both the normal and accident conditions for a shipment of nine packages.

6.3.2 Packace Recional Densities The densities used in the criticality analysis are as follows:

Material Densitv(a/cc)

U-235 17.53 H2O 0.999973 Steel 7.8 6.3.2.1 Fuel Realon Heterogeneous. and-homogeneous number densities for the fuel region interior to the fuel box are:

Material Density f at'om/ barn-cm)

Heterogeneous Homogeneous U-235 4.491-2 7.484-4 H(H 0) 6.685-2 6.574-2 O(H 0) 3.343-2 3.287-2 6.3.2.2 Fuel Box Realon The fuel. box material is specified as mild steel.

For the

analysis, ASTM grado 1005 ' stool was assumed to obtain the following heterogeneous number densities:

Material Densitv(atom / barn-cm)

Carbon

,2.346-4 Manganes.

2.992-4 Iron 8.376-2 6-3 I

9 6.3.2.3 Reflector and Moderator Reaions The analysis assumed that a water reflector surrounded an array containing a low density interspersed water moderator.

The maximum reactivity for the array occurred for an interspersed moderator density of about 5%.

The heterogeneous number densities for the reflector and moderator regions are:

-Material Qpnsitv(atom / barn-cm)

Reflector H(H 0) 6.685-2 3

O(H O) 3.343-2 2

5% Moderator H(H 0) 3.343-3 O(H 0) 1.671-3 1

.i, I

6-4 l

1

9 t

Figure 6.1 Array Model for Criticality Analysis i

End View Side View 120' S

\\

102.01' 0.0677' 1.636' L

\\

23.5' -

23.5"

,'),memus,

+ a.927' s.e27=--

5 o3 g

9

\\

\\

\\

9 T **'" ~ \\

\\

H 0, Variable Density 2

\\

\\\\

H 0,100% Dense

\\-

\\\\

f 2

j

\\

\\ \\

/

\\

\\'s

{

/

\\\\

\\

\\

l 18"_

em

\\

-h Fuel Box -

,as

==

E a c h C e ll -

(typ.)-

4 6-5

., ~

l 5 -

I 6.4 Criticality Calculation This-section describes the criticality analyses for the NNFD-SA-2 packages.

The analyses demonstrate

that, including all calculational uncertainties and bias, the shipping package remains subcritical for both normal and accident conditions.

)

6.4.1-Calculational Method The criticality analyses were performed for both the normal and accident conditions of the package.

An optimized, conservative fuel region description was assumed.

Package tolerances were chosen to provide a conservative model with optimized interspersed moderation between units of the array.

The combination of these elements assure an analysis that demonstrates safety under the most reactive conditions.

The criticality analyses for-this package were performed with the KENO-IVI Monte Carlo.

Infinitely dilute cross sections were obtained'from the 123 group XSDRN cross section setz.

This is an industry accepted methodology.

KENO-IV uses the array model described in Section 6.3.1 with the number densities listed-in Section 6.3.2 to determine the neutron multiplication f actor for an array of packages.

The input listing for the KENO-IV case for the most reactive array configuration, 5% interspersed moderation, is shown in Figure 6.3.

6.4.2

'Ontimization This analysis optimized both the fuel contents of the package and the interspersed' moderation in the array of packages.

The analysis for the: package employed these optimized parameters for both the fuel and moderator regions.

The fuel region contents consist of: clad fuel plates containing uranium-oxide wafers.

A maximum weight of 320= grams of U-235 enriched to any extent is allowed in each plate.

A limit of 4 kilograms of U-235 is allowed in the fuel region.

The packing i

material in the fuel region consists of thin polyethylene bags around each plate and industrial paper stuffing. An evaluation was performed to_ determine an ' optimized fuel loading using a plate geometry.

Based upon the results.of that study, a homogeneous U-

~235 and water-fuel model:was determined to represent an optimized fuel loading.

'A discussion of the optimization evaluation is provided.in Section 6.6.1.

.The spacing and configuration of the package array indicated that optimization of the interspersed moderation between array members must be examined.

Section 6.6.2 describes the analysis that resulted in use of an optimized interspersed water moderator density of about 5%.

a-6-6 n

6.4.3. criticality Results KENO-IV calculations were performed for an array of packages using the methodology previously described.

The results from the optimized fuel and interspersed moderation. cases were shown to i

bound any actual configuration for either normal or accident configurations.

The results from the case with a homogenized U-235 and water fuel region in an array with a

5%

dense interspersed water moderator are introduced into the equation obtained in Section 6.5 to account for bias and uncertainty:

k,,, + 2* sigma +0.04 k,

=

The KENO-IV results and calculated k, are as follows h,,,

sicma h,

0.66320 0.00283 0.709 Thus nine packages can be shipped under both normal and accident conditions with a k, significantly less than 0.95.

6.5 Critical Benchmark Calculations 6.5.1 -Benchmark-Exceriments The KENO-IV bias estimated for this calculation is based upon the comparison of KENO-IV results with those of 21 critical experiments

.as documented in reference 3.

The critical. experiments consisted of low-enriched 00 fuel pins arranged in a water-moderated lattice 2

to simulate-LWR fuel assemblies.

Twenty-one configurations >were constructed to simulate a

variety of close-packed storage arrangements.

The spacings between assemblies ranged from 0" to 2.576" with and without interspersed absorber materials..

The absorber materials included stainless steel plates,? B C rods, and 4

borated aluminum plates.

All pertinent data for. each critical configuration is' documented in reference 3 to' permit use of,these data-for validatin calculational methods according to ANSI Standard N16.9-1976'g 7

and ANSI /ANS-8.1-1983.

These benchmark experiments. provide a set of data for a general verification of the methods used for these calculations.

The fuel Lgeometry of the experiments differ from that of.the package 11n:the cylindrical pin arrangement as compared to the plate. configuration.

However,- if the experimental modeling of a fuel assembly is

. considered, the experiment approximates on a larger-scale.the plate

arrangement. of-the package.

In. addition. -the pin-by-pin representation in the assembly can be viewed as an approximation.to a: homogeneous representation of the fuel assembly.

The fuel in the.

experiment' is only enriched to 2.459 weight percent compared to-full: enrichment of the package material.

The explicit modeling of this. fuel loading including the resonance material,-

U-238, 6-7

i represents a more severe verification case than use of only U-235.

-Thus, comparison of KENO-IV results for these critical experiments will provide a more rigorous benchmark of the method.

The placement of absorber materials between the experimental fuel assemblies provide effects similar to the fuel box material l

containing the fuel.

The primary lacunae in the benchmark are explicit measurements of low density interspersed moderator.

The experimental arrangement only considers full density water, whereas the optimization calculations for the package show that about 5%

. interspersed moderation provides a maximum k-eff for the package i

array.

From a neutronics pof.nt of view, a smaller spacing of full density water, i.e. about 1.2" for the package, is equivalent to the combination of low density moderator and spacing. This spacing is bounded by the experimental results.

6.5.2 Benchmark Calculatipns Detailed information on KENO-IV benchmark calculations is provided in reference 3.

The methodology includes the 123 group XSDRN cross sections 2 5

used for the package calculttions, the NITAWL cross section processing code (used in the package calculations only to provide the proper format for KENO-IV), and the KENO-IV code.

The primary difference between the calculations provided in reference 3

and those for-the package is the computer on which the calculations were performed.

Those in reference 3 were done an a CDC computer, while those for the package were executed on a Data General Computer.

Selected experimental configurations were executed on the Data General to verify conformity with the results obtained on the CDC machine.

These are discussed in section 6.5.3 below.

6.5.3 Results of Benchmark Calculations Table 6.2 presents results for.both the critical experiments and the. KENO-IV results obtained - on the CDC computer as given in reference 3.

A review of 'the data in Table 6.2 indicates no direct correlation between the KENO-IV results-and those measured as a function of material placed between the assemblies.

The - only I

obvious correlation is related to the spacing between assemblies.

Table 6.3 illustrates.the trend.

This table lists the average calculated-to-measured: differences for core configurations 1

-through 21 for-each spacing.

The differences for cores with only water moderated assemblies is also given.-

An average bias l

. independent of the spacing is also given for all configurations and the water only configurations.

-The trend of increasing negative bias-with spacing'is apparent.

To verify the code on the Data General

computer, five configurations were, considered.-

The results of these cases both with experiment and'with-CDC results is - provided - in Table 6.4.

Results between computers generally agree within the statistics of the cases..

Comparison of the Data General results with those of 6-8 l

l 1

i

the critical experiments are shown in Table 6.5 along with the

'cesults of equivalent cases for the CDC machine.

The Data General versian shows the same trend as the CDC, i.e. bias increasing with spacing.

For small spacing, the Data General version indicates a positive bias, i.e. conservative results, whereas the CDC versjon indicates a negative bias.

Ilowever, within the statist.ics of the cases, the results are essentially identical.

Based upon the equivalent spacing of 23.5" of 5% interspersed moderation and about 1.2" of full density water, a bias of -0.011 1 0.005(case XVI of Taolo 6.5) would be appropriate.

To cover the differences in the package configuration for geometry and fuel loading, a total bias of 4%, including both calculational and measurement uncertainties, will be assumed for this calculation.

This is about twice a reasonable value and will bound any actual bias expected for these calculations.

Thus, the value for k,

which Lncludes all calculational bias and uncertainties, Is calculated for any KENO-IV result by the following equationt k,,, + 2* sigma + 0.04 k,

=

is the calculated multiplication factor obtained by KENO-Where k,Nigel. is the statistical uncertainty of the calculational IV and method.

6.6 Annendix This appendix contains a description of the optimization analyses that lead to the final KENO-IV model described in Section 6.3.

Two optimization analyses are described.

The first in Section 6.6.1 determines an optimized fuel loadinq.

The second in Section 6.6.2 uses the optimized fuel loading % 4tinian the moderation for the array calculation.

6.6.1 Fuel Loadina Ontimization 6.6.1.1 Discussion and Results The NNFD-SA-2 package accommodates uranium oxide fuel plates containing a maximum of 320 grams of U-235 to any enrichment.

A maximum of 4 kilograms of U-235 may be shipped in a package.

To ensure criticality

safety, the most reactive fuel configuration in the fuel box must be determined.

A series of calculations for a plate type fuel geometry and a homogeneous fuel configuration were done to determine an optimized fuel loading configuration.

These calculations yielded a reactivity for a homogeneous mixture of water and 0 235' metal in the fuel box that bounds any realistic configuration of the package.

6-9

6.6,1.2 Packace Puel Loadina The parameters of the fuel plates are listed in Table 6.1.

6.6.1.3 Model Soecification Two geometrical models were used to optimize the fuel loading.

The first used a plate geometry while the second homogonized the fuel over the fuel box region.

Each geometry is discussed below.

6.6.1.3.1 Plate Geometry To assess the most reactivo configuration, a single fuel box was modeled with the box-typo geometry of KENO-IV.

A series of configurations were modeled to assess the cotimum loading and arrangement of plates within the fuel box.

.he model assumed a varying numb 9r of plates within a fuel box with a 30.48 cm(12")

water reflector.

Twolve and a half fuel platos are required to provide about 4 kilograms of U-235 in the fuel box with each plate containing 320 grams.

To provide a minimum number of plates, 12 plates each with 334 grams of U-235 were modeled.

Such an arrangement provides the maximum moderation within the fuel box for the maximum loading.

The first series of 3 cases examined the arrangement of 12 plates within the fuel box.

Figure 6.2 provides a sketch of the geometry for these cases.

The first case staggered the fuel plates in the box.

This provided more moderation between each plate by positioning alternate plates such that the upper right corner of the first plate touched the upper right corner of the fuel box while the lower left corner of the second plate touched :he lower left corner of the fuel box.

The plates woro positioned with equally spaced water gaps between the fuel plates and the plates and ad-)acent walls.

A listing of the 12 element staggered case is provided in Figure 6.3.

The second case aligned the edges of the plates in the center fuel box but maintained the spacing between plates and walls.

The last case compressed the plates to remove the water gaps betwoon plates.

The KENO results of these cases are as follows, case Descriotion k-off sinma 12 Plates Staggercd 0.4412 0.0047 12 Plates Aligned 0.3719 0.0048 12 Plates Compressed 0.3156 0.0041 This indicates that the arrangement with the most ' moderator between the twelve platos 7;ovides the optimal fuel loading.

Three additional cases wre executed to determine if a reduced number of plates and increased moderator would be more optimal.

Cases for 9,

6, and 3 plates were executed with a staggered 6-10

i plate geometry.

All cases provided equal water gaps between the j

plates and adjacent walls.

The KE!10 results for these casos are as follows.

Case Description k-off g,Lgan 9 Plates Staggered 0.4434 0.0048 6 Plates Staggered 0.4207 0.0046 3 Plates Staggered 0.3348 0.0042 Thus it is seen that an optimum occurs betwoon 9 and 12 plates for the staggered configuration with water betwoon the plates.

Based upon a review of the results of the KEl10 cases, it was judged that the 12 element case would provide the maximum i

reactivity.

It was noted the polyothylene is used as a packing material.

The 12 element case was rerun with polyethylene replacing the water betwoon the fuel platos.

This case gave a effective multiplication factor of 0.4593 with a sigma of 0.0053.

The increase in k-off is expected duo to the increased hydrogen content of polyethyleno.

It is a conservative value since the polyethylono thickness of tho slooves is about-15 mils rather than the nearly 20 mils assumed for this cast.

6.6.1.3.2 Homocenized Goomotry Due to the uncertainty of tho arrangements of platos within the fuel be v, a homogonized model was examined to determine a bounding configuration.

Two homogonization techniques were examined.

The first assumed used the volume of the fuel plates to obtain the homogenized number densities.

This assumed that the U-235 volume fraction was the volume fraction of the fuel plates within the fuel box.

The second assumed the density of U-235 metal, 17.53 g/ce, to calculate the volume of the 4 kilograms of-U-235 in the fuel box.

This volume was used to obtain the U-235 volume fraction and the regional number densities.

The number densition for thoso casos are listed in section

6. 6.1. 3. 2.

The homogeneous fuel / water mixtures were then placed in a

single fuel box surrounded by a water reflector.

The results of the two casos are as follows.

Case Description k-of(

siama Fuel Plate Homogenization 0.4788 0.0050 Uranium Metal Homogenization 0.6022 0.0056 Based upon these results, it is seen that the homogonization of 4 kilograms of U-235 provides the maximum reactivity results.

This is an extremely conservativo model and is seen to bound any of the normal configurations examined.

It is the fuel model that is used for the package analysis.

6-11

6.6.1.3.3 Realonal Dengities The densities of the fuel box and water reflector are as described in Sections 6.6.3.2 and 6.6.3.3.

The densities of the fuel region are as follows.

6.6.1.3.3.1 Plate Model For the plate model the density of U-235 in the plate was obtained by dividing the mass of U-235 in the plate b,r the plate volume (495.5 g/cc).

For the plate model it was necessary to i

assume 334 grams per plate to provide 4 kilograms of U-235 with only twelve plates.

Thus, the U-235 density in the plate is 0.67 g/cc which provides a U-235 number density in the plate of 1.7268-2 atoms / barn-cm.

Polyethylene has a density of 0.92 g/cc with constituent number densitics(atoms / barn-cm) of 7.90-2 for hydrogen and 3.95-2 for oxygen.

6.6.1.3.3.2 flomoaenized Model For the homogenization based upon plato volume fraction, the heterogenous number density from the plato model above was used.

For this model the 12 fuel plates occupied 43% of the volume with the remaining 56% occupied by water.

The homogeneous number densition are:

Material llomoceneous Density f atom / barn-cm)

U-235 7.499-4

-l H (ll 0) 3.782-2 O(H 0) 1.891-2 For the case with 4 kilograms of metal homogenized over the ruel box' region the honogeneous densities as follows.

Material llomoaeneous Density f atom / barn-cm).

t U-235 7.484-4 H(H 0) 6.574-2 O (11 0 )

3.287-2 6-12

Figure 6.2 Sketches of Fuel Region Optimization Models iw.

f d;akysw

/

s a

a

,} (,

1. 1I N

M i r

. I l

I i

/ /

f i.e f

f l l-l

..e

- i..n-

1. 1 1. Statt Staggered Plate Model

/

,C....

/Yhhh

/////////////

3 7

h-l.

l 1.v

,f

/

/

/,/ /_/_/

/

/, /

/

--r. *. oc 4'

4

-r.s-e sar y

9

,l,,,.

'. 3,e i-

.hre e i ni Aligned Plate Model Compressed Alinned Plate Model 6-13

4 6

Y Figure 6.3 KENO Input Listing for Staggered 12 Plate Model 32-1200320-00, bird cage.12 plates, 334 gm/ pit 1000 70 301 3 123 75 6 4 8 10 4 2511-6 1 0 1000 00 1 00000 00 0 0 0.0 0.0 0.0 0.0 0.0 0.0 1 -922351 1.726892-3 2

10001 6.6853849-2 2

80004 3.342692-2 3

260001 8.37647-2 3

60002 2.34638-4

. 3 250005 2.99254-4 4

10001 3.342692-3 4

80004 1.671346-3 BOX TYPE 1

CUBOID 1

0.2286 0.0 12.7254 3.81 259.1054 15.24 123Z CUBOID 2

0.2286 0.0 12.7254 0.0 259.1054 0.0 123%

BOX TYPE 2

CUBOID 1

0.2286 0.0 8.89 0.0 243.84 0.0 123Z CUBOID 2

0.2286 0.0 12.7254 0.0 259.1054 0.0 123Z BOX TYPE 3

CUBOID 1

0.2286 0.0 10.785 1.905 251.46 7.62 123Z CUBOID 2

0.2286 0.0 12.7254 0.0 259.1054 0.0 123Z BOX TYPE 4

CUBOID 2

0.10844 0.0 12.7254 0.0 259.1054 0.0 123Z CORE BDY 0

4.15292 0.0 12.7254 0.0 259.1054 0.0 123Z CUBOID 3

4.324878 -0.171958 12.897158 -0.171958 259.277358 -0.171958 123Z CUBOID 2

34.805 -30.652 43.55 -30.652 289.758 -30.652 123Z 1

2 22 4

11 1 1110 2

4 24 4

111 1110 4

1 25 2

111 1111

- END CASE END KENO i

i E

1 6-14 I

J

6.6.2 Interseersed Moderation Ootimization 6.6.2.1 Qig.qussion and Results The analysis for the accident condition requires use of optimized interspersed moderation in the array of packages.

Due to the wide spacing and lack of absorbors betwoon fuel regions for the birdcage package, an evaluation of the reactivity ef fect of lower density intersporsed moderation is necessary.

The analytical model used for this analysis is that described in Section 6.3.1.

This includes a homogenized fuel region in a 6-by-6 uniform array of packages with a water reflector.

A series of cases with the interspersed moderator density varying between zero and one hundred percent density were examined to find the near optimum condition.

Based upon the analysis discussed in this section, a moderator density of about 5% provided the maximum reactivity for the reficcted array.

6.6.2.2 Packaac Puol Loadina The basic fuel paramotors aro listed in Table 6.1.

Those have been modified to represent a homogenized region of U-235 and water as discussed in Section 6.6.1.3.3.

6.6.2.3 Model Soecification A series of cases woro executed with varying densities of interspersed moderation to assess the reactivity effect of the interspersed moderator betwoon oloments of the array of packages.

The model used in the KENO-IV calculations is described below.

6.6.2.3.1 Model Geometry The geometrical model for this analysis consisted of a 6-by-6 array of packages with an 45.72 cm(18")

water reflector surrounding the array.

The fuel region consisted of the steel fuel box filled with a homogenized mixture of U-235 and water.

The fuel boxes were placed on a conter-to-center spacing of 59.69 cm(23.5") which represents the minimum square dimension of the package.

The structural material of the birdcage, i.e. the steel angles, were not included in the model.

Thus the only material between the fuel regions is the low density moderator.

A sketch of the geometry is provided in Figure 6.1.

The KENO-IV input for the 5% dense interspersed moderator case is listed in Figure 6.4.

6.6.2.3.2 Packaac Recional Densities The package regional densities are as follows.

6-15

.___._____.__a-__m

_m_m._.

_.m.. _. _. _ _. _ _

_._.-.___.--.___-.__m--s.m____-__.__.__.m.--_mm.___m.-_______________-_-_--__m-_s..-.m._.--

__m__._____*__.-te_m

4 6.6.2.3.2.1 Fuel Realon Densities Material Homoneneous Density (atom / barn-em)

U-235 7.484-4 H(H O) 6.574-2 2

O(H O) 3.287-2 2

i 6.6.2.3.2.2 Puel Box Densities The fuel box material is specified as mild steel.

For the

analysis, ASTM grade 1005 steel was assumed to obtain the following heterogeneous number densitiest Material Densityfatom/ barn-cm)

Carbon 2.346-4 Manganese 2.992-4 Iron 8.376-2 6.6.2.3.2.3

. Moderator Densities Cases with interspersed moderation at various water densities will be examined for the array casos, the number densities for these cases are:

Density ND ND 0

0.b 0.b 3

2.006-3 1.003-3 5

3.343-3 1.671-3 7

4.680-3 2.340-3 10 6.685-3 3.343-3 30 2.006-2 1.003-2 100 6.685-2 3.343-2 6.6.2.4.

Criticality calculations This section describes the criticality analyses to the determine the optimized interspersed moderation between units of the array of packages.

6.6.2.4.1 Calculational Method The calculational method is described in Section 6.4.1.

6.6.2.4.2 Ootimization The fuel loading optimization is described in Section

6. 6.1.

This section discusses the analyses used to determine the optimum interspersed moderation density.

6-16 1 '

6.6.2.4.3 Ootimitation Resulta The determination of the reactivity effect of the interspersed moderation in the array of packages is determined with a series of seven KENO-IV cases.

The results of those cases is provided below.

i Moderator Density k-eff siama 0

0.5929 0.0050 3

0.6482 0.0038*

5 0.6632 0.0028*

7 0.6410 0.0034*

10 0.5869 0.0051 30 0.4696 0.0067 100 0.5970 0.0051

• These cases were executed with additional histories after the general trend was exhibited (100K for 5%, 50K for 3 & 7%, and 20K histories for others).

Based upon these results it is soon that the maximum reactivity occurs with an interspersed moderator density of about 5%.

As was noted in Section 6.6.1.3.1, polyethylene sleeves are used as packing for the fuel elements.

In that section it was seen that for the plate geometry the replacement of water with polyethylene causes a reactivity increase of about 2% delta k.

Due to the extreme conservatism of the homogenized fuel model, the inclusion of the polyethylene was not considered a

reasonable assumption.

However, to very conservatively assess the effect of the polyethylene one additional case with 5%

interspersed moderation was executed.

This case used the polyethylene number densitics listed in Section 6.6.1.3.3.1 to replace those of water in the fuel region.

The number densities were not reduced by the water volume fraction of the region which increases the hydrogen content of the region.

The effective multiplication factor for this case is 0.7018 with a sigma of 0.0025 for 100K histories.

Thus this overly conservative case shows an increase in k-off of about 4% over the equivalent water case.

This result in still significantly below the 0.95 criticality limit.

As a final note, the k-offective of the normal condition of the array of packages, i.e. with no interspersed moderation and a close water reflector around the array should be conservatively represented by the 0% interspersed moderation case.

This k-eff is seen to be 0.5928 with a sigma ' of 0.0050.

The single package k-eff is conservatively represented. by the 100%

interspersed moderation case with a k-eff of 0.5970 with a sigma of 0.0051.

6-17

?

i i

j From these analyses, it is seen that under optimal fuel loading and moderation conditions, the array of packages is critically j

safe with a k significantly below 0.95.

They further show that both the,,n,ormal condition and the single package are safe I'

by about the same margin.

I t

n i

i 1

i i

i i

P i

k k

D k

?

I

?

3 1

f 6-18

~,,wc

-v--n-e

-we,-

see--

---

er.

-w n

--e s-v -

w

--wr*w

+

Figure 6.4 KENO Input for Homogenized Array Model 32-1200320-00, bird cage, HOMOGENIZED,6X6 ARRAY, 5 % DENSE H2O MOD 1000 70 301 3 123 7564 10 5 1

6 6 1 -6 1 0 2000 00 1 00000 00 0 0 0.0 0.0 0.0 0.0 0.0 0.0 1 -922351 7.48449-4 1

10001 6.57397979-2 1

80004 3.2869899-2 2

10001 6.6853849-2 2

80004 3.342692-2 3

260001 8.37647-2 3

60002 2.34638-4 3

250005 2.99254-4 4

10001 3.342692-3 4

80004 1.671346-3 BOX TYPE 1

CUBOID 1

6.3627 -6.3627 2.07645 -2.07645 281.9654 22.86 123Z CUBOID 3

6.53466 -6.53466 2.24841 -2.24841 282.1374 22.688 123Z CUBOID 4

29.845 -29.845 29.845 -29.845 304.80 0.0 123Z CORE BDY 0

358.14 0.0 358.14 0.0 304.80 0.0 123Z CUBOID 2

403.86 -45.72 403.86 -45.72 350.52 -45.72 123Z 1 161 161 1 11 1

END CASE END KENO 6-19 l

Table 6.2 Spacing Measured Versus Calculated Values of Keff between Material KENOIV (CDC)

Measured KENOIV-

assys, between K,,, i Unc*

K,,, i Unc*

Measured i Unc*

inches Core assvs None I

HO 0.99810.006 1.000210.0005

-0.00210.006 2

II HO 1.00710.004 1.000110.0005

+0.00710.004 2

0.644 III HO O.99910.004 1.000010.0006

-0.00110.004 2

-IV 84 B C Pins 1.00410.007 0.999910.0006

+0.00410.007 4

XI SS Plate 1.01510.004 1.000010.0006

+0.01510.004 d

XIII 1.6B/A1 Plate 1.00810.005 1.000010.0010

+0.00810.005 XIV 1.3B/A1 Plate 1.00310.004 1.000110.0010

+0.00310.004 XV O.41B/A1 Plate 0.99510.005 0.999810.0016

-0.00510.005 XVII O.24B/A1 Plate 0.99310.005 1.000010.0010

-0.00710.005

{

XIX O.1B/A1 Plate 0.99110.004 1.000210.0010

-0.00910.004 1.288 V

64 B C Pins 1.00510.005 1.000010.0007

+0.00510.005 4

VI 64 B C Pins 0.99810.004 1.009710.0012

-0.01210.004 4

XII SS Plate 0.99110.005 1.000010.0007

-0.00910.005 XVI 0.41B/A1 Plate 0.990i0.005 1.000110.0019

-0.01010.005 XVIII 0.24B/A1 Plate 1.00510.005 1.000210.0011

+0.00510.005 XX 0.1B/A1 Plate 0.99710.005 1.000310.0011

-0.00310.005 1.932 VII 34 B C Pins 0.99410.005 0.999810.0009

-0.00610.005 4

VIII 34 B C Pins 1.00310.005 1.008310.0012

-0.00510.005 4

X HO O.98810.004 1.000110.0009

-0.01210.004 2

XXI 0.1B/A1 Plate 0.98110.004 0.999710.0015

-0.01910.004 2.576 IX HO 0.98710.005 1.0030io.0009

-0.01610.005 2

• All uncertainties are 1 sigma.

b 1.6 is the aversge weight percent of boron in the borated aluminum plate.

Table 6.3 Average KENOIV-to-Measured Differences

• Spacing Cores 1-21 Average Water Cores h

h Inches (KENOIV - Experimental) i Unc (KENOIV - Exp) i Unc 0.00

+0.0025 1 0.0051

+0.0025 i 0.0051 0.644

+0 0010 1 0 0049

-0.0010 1 0.0040 1.288

-0.0040 0.0050 1.932

-0.0105 i 0.0047

-0.0120 1 0.0040 2.576

-0.0160 1 0.0050

-0.0160 1 0.0050 Core 1-21 Avg

-0.0033 i O.0048

-0.0048 1 0.0047 e

b 1

• All calculations were performed on the CDC mainframe computer.

b Unc = ( '(Unc )2/k)M where k is - the number of calculated KENOIV j

values. All uncertainties are 1 sigma.

e p_,--

w g

_f.

g 7g wp-

,6%

.y y

yaw.,

y

.gr, o+

___aw-,,

s3-

_3, m

Table 6.4 Comparison of KENOIV Calculations with Measured Data Spacing between Material KENOIV on DG KENOIV on CDC.

assys, between K,,, i Unc*

K,,, i Unc*

Measured i Unc*

inches.

Core assys None I

HO 1.00910.006 0.99810.006 1.000210.0005 2

0.644 XIX O.1B/A1 Plate 1.00310.004 0.99110.004 1.000210.0010 1.288 XVI O.41B/A1 Plate-0.98910.005 0.99010.005 1.000110.0019 1.932 XXI O.1B/A1 Plate 0.99110.004 0.98110.004 0.999710.0015 2.576 IX HO 0.98810.005 0.98710.005 1.003010.0009 2

T

• All uncertainties are 1 sigma.

i b 1.6 is the average weight percent of boron in the borated aluminum plate.

-l

,--w

.+,

9 Table 6.5 Data General KENOIV-to-Measured Differences Spacing KENOIV on DG KENOIV on CDC Inches Core (KENOIV - Meas) i Unc*

(KENOIV - Meas) i Unc*

O.0 I

+0.009 i O.006

-0.002 i O.006 0.644 XIX

+0.003 i O.004

-0.009 i O.004 i

1.288-XVI

-0.011 i O.005

-0.010 i O.005 1.932 XXI

-0.009 i O.004

-0.019 i O.004 2.576 IX

-0.012 i O.005

-0.013 i O.005 T

C:

• Unc = ( (Unc ) 2 + (Unc,) 2) M,. where Unc is the KENOIV uncertainty g

y and Unc, is the. measured uncertainty.

All uncertainties are 1 sigma and rounded to three decimal places.

h

7.0 OPERATING PROCEDURES General The NNFD-SA-2 container is routinely used to ship unirradiated uranium Fuel Elements at any enrichment of the U-235 isotope.

The detailed loading and unloading procedures are given below and are in compliance with cubpart G of 10 CFR 71.

All operating procedures for the NNPD-SA-2 container are approved by NNPD plant management.

7.1 Procedures for Loadina the NNFD-SA-2 Each container must first be inspected by Quality control in accordance with procedure,

" Inspection of in use shipping container approved by Certificate of Compliance"(E45-1) or "In use of non-B&W, NNPD Owned Specification Shipping Container"(E45-6). Shipping containers not acceptable for use shall be marked in accordance with the above procedures.

1.

Assure that the container is to be loaded per the Certificate of Compliance and record this on the appropriate shipment documentation.

2.

Move container to loading area using a fork lift or other approved handling equipment.

3.

Unbolt and remove the short " slotted angle" end stop that runs transverse to the long axis of the container.

4.

Unbolt and remove the longer " slotted angle" that holds the inner container top.

5.

Open the hinged inner container box.

6.

The contamination level (loose and fixed) shall be determined on the exterior surface of the material to be loaded.

Record the contamination levels on the appropriate form.

7.

Three knowledgeable Accountability personnel shall load the material into the inner box container.

8.

Close the hinged lid on the inner box.

9.

Band the inner box with 3/4 inch wide steel banding, 10.

Install and bolt the long

" slotted angle" that transverses to the long axis of the container and apply the 3/4 inch steel banding.

11.

Apply tampersafe seal and record appropriate information on shipping papers and the tampersafe seal application form (E4-44).

7-1

0 l

l 12.

Notify Radiation Safety to conduct radiation surveys in accordance with 49 CPR 173.441 and 49 CFR 173.443.

Record the survey results on the proper form.

13.

Move the loaded container to the storage area or shipping vehicle loading dock.

f 14.

Tie-down or blocking devices shall be used on the shipping vehicle. On the Safe Secure Trailer (SST) tie down devices provided by the DOE shall be used.

15.

The Shipping Container Checklist (E4-97) shall be completed and filed with the shipping documentation.

7.2 Procedures for Unloadina Packace The following procedure shall be used in situations when NNFD personnel are required to unload containers.

1.

Notify Radiation Control to conduct surveys to determine contamination

levels, and assure contamination levels are in compliance with limits specified in 49 CPR 173.441 and 173.443 and the unloading area.

If not, the area shall be roped off identifying it as a controlled area.

Record results on form E4-50.

2.

Container to be moved by lifting with a fork lift or other appropriate moving devices.

3.

Verify the tampersafe seal and record on receipt inspection form.

4.

Remove the tampersafe seal (s).

5.

Remove banding from the outer container (if.

applicable).

6.

Unbolt and remove the short '-slotted angle" that runs transverse to the long axis of the container.

7.

Unbolt and iemove the longer " slotted angle"that holds the inner container top.

8.

Remove the inner container from the birdcage frame.

Cut and remove the steel banding from around the inner container (if applicable).

9.

Open the hinged inner box container.

10.

Remove the material and associated packing tom the hinged box and place in'an approved storage location within the receiving facility.

7-2

I 11.

Clean the inner container, if necessary. Secure the inner container top and install the outer container lid.

Label the NNFD-SA-2 container as " Empty" and place in storage or return to shipper.

7.3 ELepJration of Jmnty Packace for Transnort Each NNFD-SA-2 shipping container shall be inspected prior to shipment to assure that the following requirements are mett o

All labels from previous shipments shall be removed from the con'ainer.

o Inner container is empty.

Shipping container is labeled

" Empty".

o The containers shall be surveyed to ensure contamination levels are within the requirements as described in 49 CFR 173.427.

o The empty package shall be securely closed and sealed in the presence of security personnel.

7.4 Appenclix None Applicable.

l l

l 7-3 1

L

L O

8.

ACCEPTANCE TE8T8 AND MAINTENANCE PROGRAM 8.1 Accentance Tests l

8.1.1 Visual Inspection All NNTD-SA-2 containers are visually inspected to the design requirements at time of fabrication.

i 8.1.2 Etructural and Pressure Testa

]

Not Applicable.

8.1.3 Leak Tests Not Applicable.

8.1.4 Component Tests Not Applicable.

8.1.5 Tests for Shieldina Intearity Not Applicable.

8.1.6 Thermal Accentance Tests Not Applicable.

8.2 Maintenance Procram The NNPD-SA-2 Shipping container is not a pressure vessel, employs no shielding materials, and does not require a cooling system or other thermal mechanism for dissipation of heat.

l Materials of construction are commonplace,

durable, and readily available.

The container has no systems or subsystems such as valves, rupture disks, or other moving components.

1 The maintenance program for the NNFD-SA-2 consists of repair, refurbishment, or replacement as necessary.

Containers are L

visually inspected prior to.cach use, and deficiencies noted and recorded at that time.

Packages with unacceptable l

conditions are temporarily stored until such time the l

container can be redressed to conform to DOT specifications.

8-1

0 l

9.0 REFERENCES

j

)

1.

L.M. Petrie, N.F. Cross, " KENO IV, An Improved Monte Carlo Criticality Program,"

ORNL-4938, Oak Ridge National Laboratory, November, 1975.

2.

W.R. Cable, "123-Group Neutron Cross Section Data Generated From ENDF/B-II Data for Use in the XSDRN Discrete Ordinates Spectral Averaging Code",

DLC-16, Radiation Shielding Information Center (1971).

3.

M.N.

Baldwin, et al.,

" Critical Experiments Supporting Close Proximity Water Storage of Power Reactor Fuel," BAW-1484-7, Babcock & Wilcox, Lynchburg, Virginia, July 1979.

4.

American National Standard, " Validation of Calculational Methods for Nuclear Safety criticality Saf ety," ANSI N16.9-1976.

5Property "ANSI code" (as page type) with input value "ANSI N16.9-1976.</br></br>5" contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process..

L.M. Petrie, et al.,

"NITAWL(Nordheim's Integral Treatment and Working Library),"

AMPX Module, ORNL/TM-3706, Oak Ridge National Laboratory, Oak Ridge, Tennessee, March 1976.

6.

Regulatory Guide 7.9, " Standard Format and Contents of Part 71 Applications for Approval of Packaging for Radioactive Material" Proposed Revision 2,

U.S.

Nuclear Regulatory Commission, dated May 1986.

7.

American National Standard, " Nuclear Criticality Safety in Operations with Fissionable Material outside Reactors",

ANSI /ANS-8.1-1983.

L i

I i

9-1 I