ML20199H002

Application for Amend to License SNM-1227,including,as Authorized Activity,Storage of Moderated SNM in sea-land Containers with Storage Grids Fastened to Floors

ML20199H002
Person / Time
Site:	Framatome ANP Richland
Issue date:	01/21/1999
From:	Edgar J SIEMENS POWER CORP. (FORMERLY SIEMENS NUCLEAR POWER
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
JBE:99:004, JBE:99:4, NUDOCS 9901250087
Download: ML20199H002 (11)

Text

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L SIEMENS l

i January 21,1999 JBE:99:004 l

U.S. Nuclear Regulatory Commission i

Attn: Document Control Desk I

Washington D.C. 20555 i

k I

Gentlemen:

i

Subject:

License Amendment Application - SNM-1227, Docket 70-1257; Storage of Moderated Special Nuclear Material (SNM)in Sea-Land Containers Siemens Power Corporation (SPC) requests an amendment to its materials license to include, as an authorized activity, the storage of moderated SNM in sea-land containers with storage grids fastened to the floors.

Backaround SPC has periodically used sea-land containers to store UO pellets and uranium powder. In 2

early 1998, SPC completed its Operations Scrap Warehouse for the storage of closed, free of external contamination containers of unmoderated uranium compounds. At various workstations on plant, SPC generates moderated uranium compounds designated for i

recovery by solvent extraction. SPC needs added capacity for lag storage of this material.

The major components of the proposed storage system are:

1.

Sea-land containers, including storage grids for moderated SNM fastened to the floor; and 2.

Storage pails which meet the following dimensional requirements: diameter 5 11.25 inches and height s 13.25 inches. For storage of moderated safe batches, 4-gallon high-density polyethylene (HDPE) containers are most frequently used.

The dimensions of the 4-gallon containers used satisfy the required dimensions.

Other containers are acceptable, as long as the prescribed conditions are met.

(

I Radiation and Environmental Protection and Fire Safety Radiation and environmental protection will be provided as described in c,hapters 3,5,12, I

and 13 of SPC's license agplication. The containers of SNM to be stored are closed and Yn D.

• v*'

Siemens Power Corporation I

[

2101 Hom Rapids Road ~

Tel:

(509) 375-8100 RicNand, WA 99352 Fax:

(509) 375-8402 9901250007 990121 I

PDR ADOCK 07001257 %

C PDR b

l Document Control Desk JBE:99:004 l

January 21,1999 Page 2 free of significant external co itamination. Fire protection will be provided by minimizing combustible materials in the sea-land containers.

Criticality Safety Criticality safety will be maintained generally in accordance with the provisions of chapters 4 and 16 of SPC's I; cense application. Specifically, criticality safety of the moderated safe batch storage arrays in sea-land containers is achieved through use of pails which meet the dimensional requirements discussed above, moderated storage grids which provide 1 foot edge-to-edge spacing, and mass control of the materialinside each pail. Discussion of the criticality safety analysis and results are provided below.

Introduction and Summary The storage of moderated fissile material in pails was modeled in KENO.Va as an l

infinite planar array. The parameters used in the calculations are summarized in Table

1. Structural steel was conservatively omitted. One-foot edge-to-edge spacing was l

provided between pails. Under normal conditions (actual operations), the pails will be l

placed in grids located around the perimeter of the sea-land containers.

l 1

Analytical Methodology and Benchmarking SPC currently uses the SCALE-4.2 system of codes to do criticality safety evaluations. This syatem of codes has been extensively used and validated by SPC for this use. Documemation of the majority of SPC's validation efforts is included in EMF-94-175, " Validation and Verification of KENO.Va."

SPC code validation for urania powders is beaed on models of 36 benchmark experiments involving homogeneous uranium oxides. The 36 banchmark experiments SPC modeled are based on the experiments doce.' anted in "Y-1948 Validation of the ' KENO' Code for Nucivar Criticality Safety Ca.culations of Moderated, Low-Enriched Uranium Systems," G.R. Handley, C.M. Hopper, Union Carbide, Oak Ridge Y-12 Plant, Oak Ridge, TN, June 13,1974. The calculation bias has been determined to be 1.5051E-3. This bias is non-conservative and must therefore be added to the KENO calculated k,, + 2a when establishing upper limits on k,,,.

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Norma! Conditions l

Under normal conditions, containers with dimrasions s 13.25 inches high and s 11.25 inches in diameter containing less than 45% af a critical mass are stored one-foot apart in each of two rows. The rows are approximately 4 feet - 8 inches apart and six-inches from the sides and ends of the sera-land containers. SPC evaluated the seasitivity of k,n with respect to pail fill height, moisture content of UO,, rasu enrichment, pail diameter, mass of UO, per pail, HDPE content in pail walls, film thickness of water on pails, low-density polyethylene (LDPE) wrap on pails, pail spacing, and interspersed moderation for normal and abnormal mass loading. The i

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1 Document Control Desk JBE:99:004

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January 21,1999 Page 3 sensitivity of k,,, with respect to overbatching the mass of UO, per pail and violating spacing requirements is summarized in Table 2.

To determine the effect of the fill height of UO, within each pail, cases were lan which varied the fill height from approximately 20% to 100%, while maintaining 18 kg (safe batch) of 5 wt% 2asU enriched powder in each pail. Interspersed moderator (IM) was also varied from dry to fully flooded. The results are presented in Figure 1 and show that, for a specific batch size, pails filled with a lower density powder are more reactive than partially filled pails with a higher density powder in this arrangement due to increased neutron interaction between containers with the higher fill height.

Since lower 23sU enrichments have higher allowed mass limits, cases were run to determine how k,,, changes when the pails are filled with safe batches of various 23sU enrichments. In light of the results of the fill height stuo'y, above, these calculations contained pails filled with a safe batch (45% of a minimum critical mass) of UO2 powder saturated with H 0. The 23sU enrichment was varied from 5 wt% down to 2 2

wt%. The results are presented in Figure 2 and show that, for respective batch limits, full pails of moderated 5 wt% 2asU enriched powder are more reactive in this arrangement than pails containing lower enriched powder (higher allowed mass).

Sensitivity studies were also performed for container diameter, removal of HDPE from pail wall, water film on pail wall, and LDPE wrap around pails. The values of k.,, resulting from these studies are summarized in Table 2. After adding 2a and the bias value (1.5051E-03), all k n results for these conditions are below 0.95.

o Abnormal C:;,rattions One credible abnormal condition is overbatching the mass of material in one or more pails. The following overbatching errors were investigated:

2 Double batching the allowed mass of 5 wt% 3sU enriched UO powder (36 kg 2

per pail) in the center 25 pails in each 9x9 array of pails (-30% of pails are double batched). All other pails contain a safe batch. All pails contain powder saturated with H 0. The 9x9 array is repeated infinitely in the X and Y 2

directioris.

Double batching the allowed mass of 5 wt% "5U enriched UO, powder (36 kg per pail) in the center 3 rows of each 9 rows of pails (-33% of mi's are double batched). All other pails contain a safe batch. All pails coatain powder saturated with H 0. The 9x9 array is repeated infinitely in the A and Y 2

directions.

Each pail in the infinite planar array is filled with 1.5 times a safe batch of 5 wt% 23sU enriched UO powder (27 kg per pail) saturated with H 0.

2 2

The center pail in each 9x9 section of the infinite planar array is filled with 2 e

g/cc UO (43.166 kg UO ) saturated with H 0.

2 2

2

l Document Control Desk JBE:99:004

{

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. January 21,1999 Page 4 The center pail in each 9x9 section of the infinite planar array is filled with 4 g/cc UO (86.332 kg UO ) saturated with H 0.

2 2

2 Another credible abnormal condition is a violation of the spacing requirements. The following spacing errors were investigated:

2 spacing violations: 5 adjacent pails in a row.

2 spacing violations: 5 adjacent pails in an "L" shape.

1 2 spacing violations: 4 adjacent pails in a "T" shape.

e 2 spacing violations: 2 sets of 3 adjacent pails (in a row), f acing each other,

)

one foot apart.

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1 pail was stacked on each of the center 3 pails in each 9x9 section of the I

infinite planar array.

Edge-to-edge spacing between pails in the infinite planar array was decreased to 10".

Finally, calculations were performed to determine the maximum k,n resulting from -

placing an overbatched (1.5 times a safe batch; 27 kg) pail in the required spacing between two pails in the infinite planar array.

The results of these abnormal conditions are included in Table 2. All of the conditions analyzed result in maximum k n values less than 0.97 (including 2a and the bias).

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Docun ant Control Desk JBE:99:004 January 21,1999 Page5 l

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Table 1 Sumrnary of Parameters l

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. CONDITIONS A f s ;lm%SSUMED IN ANALYSIS 3 '%., <,g,g,'M'to MidefrdhaMps 1 ',

.. g'

~

• g 1

[., <<

"'f )

k icriticaRy aiulysis'and 'is therefore not limitedE M'"'

~ PARAMETER $f

y;dt d

< r MATEPJAL COMPOSITION Chemical Form UO -H O 2 2 Physical Form Powder Enrichment s 5.0 wt% 8U Maximum Density 4 g UO/cc DEGREE OF MODERATION Powder saturated with H O (crtimal) 2 Optimal moderation between interacting units in most cases GEOMETRY Shape Cylinder Dimensions Diameter:

11.2 5" lD Height:

13.25" Wall Thickness 70 mit (0.07") Nominal Wall Material HDPE DEGREE OF REFLECTION ProximVy Close fitting on top and bottom Top 30 cm water Bottom 30 cm water (some cases include concrete)

Sides None (infinite planar array) j INTERACTING UNITS

]

Numher of Units infinite planar array Spacing Between Units One-foot edge-to-edge NEUTRON ABSORBERS None l

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1.

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Document Control Desk JBE:99:004 Januant?1,1999 Page 6 Table 2 Summary of Results Case ID '

f. "U t '

-: kg U0,;

~ Volume % ::

', S;-

M Comments zo Mroe-?),

m.

( Enrichment

.' Per'Pau 'i interspersed J W"

+'

L(h%)'

Mderator !

m r~

everage Q :.o;

. ~evg + 2c + bles -

s500f.OOO 5.0 15.0 0

0.88326 0.00225 0.88927 Pails filled with moderated safe batch, full water reflection (f wr) s500fC.OOO 5.0 18.0 0

0.89714 0.00200 0.90265 Same as above, except concrete reflector below the array s500fd.OOO 5.0 18.0 0

0.88233 0.00223 0.88033 Pails with inside diameter reduced to 10.46",

fwr s500fnp.OOO 5.0 18.0 0

0.87910 0.00216 0.88493 Pails with no HDPE walls, fwr s500ff.OOO 5.0 18.0 0

0.88406 0.00220 0.88997 Pai!s with O.055 cm H O film on outside of 2

walls, fwr s500f2p.OOO 5.0 18.0 0

0.88490 0.00201 0.89043 Pails wrapped in 20 mit LDPE, fwr da500f.OOO 5.0 36.0 0

0.92941 0.00222 0.93536 Double batched mass in center 25 pails in 18.0 each 9x9 section of the infinite planar array, fwr db500f.OOO 5.0 36.0 0

0.92987 0.00226 0.93590 Double batched mass in center 3 rows in each 18.0 9x9 section of the infinite planar array, fwr 15oSOOfC.OOO 5.0 27.0 0

0.95884 0.00207 0.96449 All pails contain 1.5 x safe batch, water reflector above array, concrete reflector below array 2gfC.090 5.0 43.166 90 0.92422 0.00289 0.93151 Center pail in each 9x9 section of the infinite f

18.0 planar array filled with 2 g UO /ce, water 2

s reflector above array, concrete reflector below array 4gfC.OOO 5.0 86.332 O

O.89534-0.00203 0.90091 Center pailin each 9x9 section of the infinite 18.0 planar array filled with 4 g UO /cc, water 2

reflector above array, concrete reflector below array 7 2av500f.080 5.0 18.0 80 0.92769 0.00243 0.93406 2 spacing violations: 5 pails in a row,

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repeated in each 9x9 section of the infinite lj planar array, fwr v

9 a

Document Control Desk JBE:99:OO4 January 21,1999 Page 7 Case lD) -

d *5U.N]c skgUOfi iVolume %t

' :'!~M W ?kyjns 1 y

Comments J

J.f

?,% ;M (. _

%?)[ - ' EMM i:Per Psil)

Interspersed W ;g b

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W j ' N 'I ;y

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A s

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• Moderator O?

1. 5

+

4 s

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->qjy n everage _

qcow avg 42o 4 bles t

94M-WW c

g-

, 3.

2bv500f.060 5.0 18.0 60 0.93507 0.00229

.0.94116 2 spacing violations: 5 pails in an *L* shape, repeated in each 9x9 section of the infinite planar array, fwr 2cv500f.050 5.0 18.0 50 0.94897 0.00251 0.95550 2 spacing violations: 5 nails in a "T' shape, repeated in each 9x9 section of the infinite planar array, fwr 2cv500fC.050 5.0 18.0 50 0.95298 0.00219 0.95887 Same as above, ext opt concrete re flector below the array 2dv500f.070 5.0 18.0 70 0.91588 0.00247 0.92233 2 spacing violatiors: 2 sets of 3 paUs in a row, facing each 9ther, l' spart, repeated in each 9x9 sectior of the infinite planar array, fwr 350.000 5.0 18.0 0

0.90549 0.00207 0.91114 1 pail stacked in each of the 3 center pails in each 9x9 sect'on of the infinite planar array, water reflectr r above array, concrete reflector below array 100sC.OOO 5.0 13.0 0

0.91425 0.00202 0.91980 Edge-to-edge spacing between pails in tha infinite planar array reduced to 10", water refiector above array, concrete reflector below array Iv150C.OOO 5.0 27.0 0

0.95592 0.00243 0.96229 1 overbatched pail (1.5 x safe batch) in 18.0 required space between 2 pails, repeated in each 9x9 section of the infinite planar array, water reflector above array, concrete reflector l

below array

=. -

Docum:nt Control Dask.

JBE:99:004 January 21,1999 Page 8 t

Mmted Safe Batch Safe Batch (18 kg) of 5 wt% U-236 Fill Height Study i

1.00 0.95 a

0.90 -

S 0.85 %s* e - -

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n

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f i

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0.50 ~ xma -

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D.40 d

80 80

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,,0 vof% intempersed moderator l

1 Figure 1 Pails with Moderated Safe Batch (18 kg) of S wt% 2ssU Enriched UO Powder L

2 Saturated with H 0, Fill Height Sensipvity Study l

2 4

4 4

W

-=

-., _.. ~

. ' Docum2nt Control Desk JBE:99:004 January 21,1999-Page 9

?

r Akxterated Safe Batch. Safe Batch of Various Enrichments Enrichment Study i

.1.00 i

I 0.95 -

l j

0.90 I

1. h : N 4.ge::, _..

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- e-6.00 W% U2%

0.85 n.

(18 kg UO2) p,,_ p _g

<$ C g' " ? "" N $- - f,((,6 - a ~~

s ' 4--&--e-e---', -- e - 4.00 wt% U235

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(25 kB U02) j 0.80 i

- a-3.00 wt% U235 x

(42 kg UO2) k"w

-- x - 2.00 wt% U235 0.75 -

(102 kg UO2) w

-x x- - x -

0.70 0

20 40 60 80 100 120 vol% hiterspersed moderator

' Figure 2 Pails with Moderated Safe Batch of Variot.s 23su Enrichments (2 to 5 wt% 23sU), UO2 Powder Saturated with H 0, Enrichment Sensitivity Study 2

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D:cumtnt Control Dssk JBE:99:004 s

Janu-sry 21,1999 Page 10-l l

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i e

l Enclosed in support of this application, in addition to the information presented above, are six copies of page 1-11 of SPC's license application.

If you ' nave any questions oi require more.

nation, please contact me at 509-375-8663.

Very truly yours, i

J s B. Edgar Staff Engineer, Licensing

-/pg.

1 Enclosure l

l

Siemens Power Corporation - Nuclear Division eup.2 SPECIAL NUCLEAR. MATERIAL LICENSE NO. SNM-1227, NRC DOCKET NO. 20-1257 l

j PART I-LICENSE CONDITIONS

REV, t

l TABLE l-1.1 Specific Locations of Authorized Activities (Cont.d) i location SN_M Authorized Activity Sea-land Containers

&cnium Oxide (up to 5 wt, Storage of a planar array of I

% U-235) closed containers of moderated uranium oxide which are externally free of significant I

contamination, j

l t

i lJ AMENDMENT APPLCATION DATE:

PAGE NO.:

i January 21,1999 1-11 l

SPC-ND 3330 047 (R 007/92)

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