ML23331A693

Appendix 4, Ujv Report: Z-1172-Amendment 1, a SKODA MCNP Calculation of Cask Criticality for Atabor Internals of Thickness 4 Mm, Amendment 1, May 2004

ML23331A693
Person / Time
Site:	07103103
Issue date:	05/01/2004
From:	Secured Transportation Services
To:	Boyle R Office of Nuclear Material Safety and Safeguards, US Dept of Transportation (DOT), Office of Hazardous Materials Safety
Shared Package
ML23331A280	List: ML23331A675 ML23331A681 ML23331A683 ML23331A684 ML23331A686 ML23331A688 ML23331A690 ML23331A692 ML23331A693 ML23331A695 ML23331A697 ML23331A698 ML23331A700 ML23331A702
References
CAC 001794, EPID L-2023-DOT-0004
Download: ML23331A693 (10)

Text

Ústav jaderného výzkumu ez a.s.

Divize reaktorových sluzeb

ÚJV Report: Z - 1172 - Amendment 1

MCNP Calculation of Cask Criticality for ATABOR Internals of Thickness 4 mm

- Amendment 1

Prepared by: Stanislav Flíbor

Department Manager: Ing. Milan Marek, CSc.

DRS Manager: Ing. Jan Kysela, CSc.

ez, May 2004

píloha 4Adod1-kritinost.doc

1. Fuel EK-10 with 10% enrichment of 235U in a square stainless steel sheath

1.1 Material composition of fuel

Used library of effective cross-Enrichment 10.00% sections 235U weight portion 7.67% 92235.60c 238U weight portion 69.01% 92238.60c Mg weight portion 13.00% 12000.60c O weight portion 10.32% 8016.60c

235U weight 128.80 g 238U weight 1159.20 g Mg weight 218.36 g O weight 173.35g

Total 1679.72g

Active part length 50 cm Fuel volume 307.8761 cm3

U density 4.1835 g.cm-3 Fuel density 5.4558 g.cm-3

U atomic density 1.0597E+22 at.cm-3 Fuel atomic density 4.9364E+22 at.cm-3

235U mol. weight 235.0439 g.mol-1 238U mol. weight 238.0508 g.mol-1 Mg mol. weight 24.3050 g.mol-1 O mol. weight 15.9994 g.mol-1

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Fig. 1: Model of a basic cell with fuel EK-10 10% in a square stainless steel sheath

Fig. 2: Cross section of a cask with fuel EK-10 10% in a square stainless steel sheath

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Fig. 3: Longitudinal section of a cask with fuel EK-10 10% in a square stainless steel sheath

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1.2 Results of calculations for the change of water density

Water density keff error Water density keff error

[g.cm-3] 2 [g.cm-3] 2 0.001161 0.1691 0.0008 0.5 0.3461 0.0024 0.025 0.1956 0.0011 0.525 0.3499 0.0025 0.05 0.2154 0.0013 0.55 0.3540 0.0023 0.075 0.2308 0.0014 0.575 0.3589 0.0025 0.1 0.2437 0.0015 0.6 0.3669 0.0027 0.125 0.2540 0.0016 0.625 0.3655 0.0027 0.15 0.2627 0.0016 0.65 0.3718 0.0024 0.175 0.2721 0.0016 0.675 0.3767 0.0028 0.2 0.2785 0.0018 0.7 0.3810 0.0027 0.225 0.2873 0.0018 0.725 0.3837 0.0026 0.25 0.2938 0.0020 0.75 0.3929 0.0029 0.275 0.3002 0.0018 0.775 0.3968 0.0027 0.3 0.3044 0.0019 0.8 0.3999 0.0026 0.325 0.3099 0.0021 0.825 0.4067 0.0027 0.35 0.3150 0.0022 0.85 0.4078 0.0030 0.375 0.3202 0.0021 0.875 0.4134 0.0030 0.4 0.3244 0.0022 0.9 0.4178 0.0030 0.425 0.3300 0.0022 0.925 0.4267 0.0029 0.45 0.3344 0.0023 0.95 0.4263 0.0030 0.475 0.3412 0.0023 0.975 0.4345 0.0031 0.998203 0.4338 0.0028

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1.3 Results of calculations for flooding a cask with water

Water level in a cask keff error

[cm] 2

-5.75 0.1684 0.0009 4.25 0.1791 0.0012 9.25 0.2036 0.0014 14.25 0.2583 0.0018 19.25 0.3054 0.0024 24.25 0.3434 0.0026 34.25 0.3899 0.0029 44.25 0.4200 0.0029 54.25 0.4311 0.0031 64.25 0.4360 0.0029 74.25 0.4367 0.0034 84.25 0.4353 0.0029 94.25 0.4343 0.0030

(zero water level corresponds to the cask bottom)

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1.4 Results of calculations for individual tolerances

keff error 2

Calculations for individual temperature states of a cask 95,3°C - option 1 acc. to Ae 10622/Dok Rev.1 0.4339 0.0024 132,4°C - option 2a acc. to Ae 10622/Dok Rev.1 0.4325 0.0023 103,6°C - option 2b acc. to Ae 10622/Dok Rev.1 0.4325 0.0023 88,4°C - option 3a acc. to Ae 10622/Dok Rev.1 0.4333 0.0025 103,9°C - option 3b acc. to Ae 10622/Dok Rev.1 0.4322 0.0024 232°C - option 4 acc. to Ae 10622/Dok Rev.1 0.4339 0.0023

Calculations for B concentrations in ATABOR 1,2 % 0.4338 0.0028 1,6% 0.4150 0.0023

Calculations for tolerances of ATABOR internals thickness 3,6 mm 0.4338 0.0028 4,0 mm 0.4283 0.0024

Calculations for tolerances of total U weight in fuel

-5% 0.4271 0.0025

+5% 0.4421 0.0025

Calculations for enrichment tolerances

-1% 0.4328 0.0024

+1 0.4321 0.0025

Calculations for specified tolerances of matrix contents 11.7 % portion of Mg 0.4316 0.0024 14.3 % portion of Mg 0.4320 0.0024

Calculations for displacement of elements inside the rack Cask resting on its side 0.4281 0.0022 Aggregation of elements 0.4271 0.0022

Calculations for tolerances of fuel active part length 48 cm 0.4374 0.0025 52 cm 0.4296 0.0025

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1.5 Conclusion With respect to criticality the transport and stor age cask for spent fuel from research reactors for fuel EK-10 with 10 % enrichment of 235U in a square stainless steel sheath satisfies the requirement for subcriticality according to §7 of the SÚJB Decree No. 106/1998 Col.

keff = 0.460

The resulting value of keff was determined according to the formula indicated in Chapter 5.

This calculation is conservative with respect to the number of fuel rods in one sheath (calculated for the maximum possible number of rods).

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