ML19211A978
| ML19211A978 | |
| Person / Time | |
|---|---|
| Site: | 07105467 |
| Issue date: | 06/30/1979 |
| From: | Honkonen D E.I. DU PONT DE NEMOURS & CO., INC. |
| To: | |
| Shared Package | |
| ML19211A967 | List: |
| References | |
| 14941, DPSPU-79-124-2, NUDOCS 7912210434 | |
| Download: ML19211A978 (13) | |
Text
DPSPU 79-124-2 (DPSP 79-716)
SUPPLEMENT TO SAFETY ANALYSIS REPORT FOR PACKAGING STEEL BANDED WOODEN SHIPPING CONTAINERS FOR SLIGHTLY ENRICHED URANIUM METAL (NLCO 1107) s June 1979 Compiled by D. L. Honkonen l'
E. l. du Pont de Nemours and Company Savannah River Plant Aiken, South Carolina 29801 S'
1637 166 10211 PREPARED FOR THE U.S. DEPARTMENT OF ENERGY UNDER CONTRACT AT(07-2) 1 12210
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DPSP-79-71-6
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.e u CC:
M. M. Anderson, 773-A D.
Baker, Jr., 773-A INTER-OFFICE MEMORANDUM A.
C. McPherson, 777-M
- h. K. Clark, 773-A SAVANNAH RIVER Pt. ANT J. Jiunnies, 703-A L. C. Brown, 704-M C. W. Mettlen, 704-M V. L. Smith, 321-M W. T. Dickenson, 703-4A H. A. Larson, 703-4A A. A. Gates, 703-llA D. A. Ward, 703-A B. S. Spang?.er, 704-M S. P. Rideout, 704-D H. A. Hardt, 313-M M. K. Carlson, 320-M June 20, 1979 TO:
\\_Ju K. PRICE LABORATORY OPEh TIONS AND SERVICES SECTION L. HONKONEN'"~'-Q 4
FROM:
D.
REACTOR AND REACTOR MATERIALS TECHNOLOGY DEPARTMENT SUPPLEMENT TO " SAFETY ANALYSIS REPORT FOR PACKAGING, STEEL B8NDED WOODEN SHIPPING CONTAINERS FOR SLIGHTLY ENRICHED URANIUM FETAL" INTRODUCTION A total of 36 tons of slightly enriched uranium metal in the form of Mark VR, VE, and 15 slugs and cores is to be returned to NLO from Building 777-M.
The most practical method of ship-ping this uranium is in the NLO wooden containers in which it was originally received (Reference 1).
However, existing ship-ping regulations were written after this uranium was shipped and the Certificate of Compliance, COC, (Reference 2) does not authorize the shipment of this uranium in these boxes and the Safe y Analysis Report for Packaging, SARP, (Reference 1) does not atscuss this uranium.
Therefore, this supplement to the SARP is intended to provide the basis for revision of the COC to permit shipping Mark VR, VE and 15 cores and slugs in NLO wooden containers.
SUMMARY
Mark VR, VE and 15 cores and slugs may be safely shipped in NLO wooden boxes by limiting the mass of uranium in each ship-ment as specified in Table 6.
These limits ensure subcritical-ity even if all cores or slugs come out of the boxes and are arranged in the most reactive array in water.
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1637 lis/
J. K. PRICE DPSP-79-71-6 DISCUSSION The adequacy of NLO wooden shipping containers (boxes) for ship-ping other forms of slightly enriched uranium is described in reference 1.
This discussion will cover only those aspects that are different.
Box Contents The NLO boxes and their maximum contents are specified in Table 1.
The material to be shipped is in the form or hollow cylinders of uranium matal withsa thin nickel plate, bare cores, and with an additional aluminum cladding, canned slugs.
These are des-cribed in Table 2.
Nuclear Criticality Safety Nuclear critiestity safety of each shipment of Mark VR, VE, and 15 will be ensured by shipping only a mass that can not be crit-ical at the opticnum arrangement in H 0, i e.
it is assumed that 2
in an accident the boxes would not maintain the slugs (or cores) at a close-packed, less reactive spacing.
These safe masses were calculated by the MGBS, TCAN, and KEFF codes (Reference 3).
Mark VE Canned Slugs -
The material bucklings of regular square lattices of Mark VE inner and outer canned slugs in water were calculated with the MGBS code for several lattice pitches.
These bucklings were adjusted based on correlations of MGBS and experi-ments for Mark VE slugs in water (Reference 4).
Extrapolation distances were calcdated by TGAN, and finally, critical and safe masses were calculated by KEFF.
Safe masses were defined as those corresponding to a keff = 0.98 (Reference'4).
The results of these calculations, given in Table 3, show that with full flooding the maximum safe mass of inner slugs is 3.4 tons and of outer slugs is 21.4 tons.
However, subsequent calculations for Mark VR and Mark 15 outer slugs show that significantly lower masses occur if the axial cavity of the outer slugs contain no water, but there is water between the slugs, (References 5 and 6).
Such a condition could occur with tightly fitting box lids that seal the axial cavity of the core or slug so that water only fills the space between the cores or slugs if the box is submerged.
No such ca culations were made for Mark VE outer slugs, but the maximum sats mass for Mark VE outer slugs can be conservatively chosen as the same as for Mark VE inner slugs, 3.4 tons.
Calculations for Mark VR described below show that this provides a large margin of safety.
Mark VR Canned Slugs - Critical and safe masses of Mark VR slugs were calculated using the procedure described for Mark VE except that the outer slugs had H O between them but the axial cavity 2
was void (Reference 5).
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J. K. PRICE DPSP-79-71-6 The results of these calculations, given in Table 4, show that the maximum safe masses of inner and outer slugs are 6.9 and 16.3 tons of uranium, respectively.
Additional calculations were performed to compare the safe masses calculated for square arrays with those calculated for triangular arrays and safe masses for fully flooded outers with those for axial cavity void outers.
At each water to uranium volume ratio, square lattice arrays gave slightly lower safe masses than did triangular arrays; e.g. the maximum safe mass of inner bare cores was 5.56 tons for a square array, and 5.91 tons for a triangular array.
The calculations show that fully flooded outer bare cores could not be critical (maximum k. = 0.988),whereas 23 tons could be critical with the axial cavity void.
Similarly, themaximumsafe(k,bk=theaxialcavityvoid,respectively.
0.98) masses are 153 and 13.8 tons for full flooding and wl Mark 15 Bare Cores - Safe masses were calculated for fully flood-ed Mark 15 inner cores and for Mark 15 or,ter cores with the axial cavity void (Reference 6).
The results, summarized in Table 5, give a maximum safe mass of 1.34 and 4.19 tons of uranium for inner cores and outer cores, respectively.
Shipment Limits - The slugs and cores will be loaded, with their axes vertical, into the NLO boxes as specified in Table 1.
The boxes will be sealed using steel bands, and then they will be loaded onto a truck in a single layer (no stacking will be per-mitted).
The smallest safe masses of uranium from Tables 3,4, and 5 shall be the limits for each Fissile Class III shipment (Ref-erence 4), as listed in Table 6.
Only one material type, e.g.
Mark VR inner canned slugs, may be in each shipment except that Mark 15 inner bare cores may be shipped with Mark 15 inner canned slugs and Mark 15 outer bare cores may be shipped with Mark 15 outer canned slugs.
Compliance with the above limits ensures that these shipments satis-fy the " Specific Standards for a Fissile Class III shipment"
@eference 7).
o Two identical undamaged shipments in contact and closely reflected on all sides by water would be subcritical.
The uranium in these two adjacent shipments would be in a layer (slab) whose thick-ness is equal to the length of the uranium.
Results of calculations using the MGBS, TGAN, and KEFF codes show that the maximum safe (keff= 0.98) thickness of an infinite slab with these uranium cores and slugs at the most reactive spacing in water and with a close fitting water reflector on all sides is greater than the actual thickness (see Table 7).
Thus, the two adj acent undamaged shipments in which the cores and slugs are not in water, a less reactive condition, are suberitical by a mup4 larger margin than shown.
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J. K. PRICE DPSP-79-71-6 o
No attempt is made to evaluate the safety of a shipment if the boxes of these slugs or cores are subjected to the hypothetical accident conditions specified in regulations (reference 8).
- Rather, it is assumed that all the cores or slugs would come out of the boxes and would be arranged in the most reactive array in water, full flooding for inner cores and slugs and the axial cavity of outer cores and slugs void.
As discussed previously, the maximum masses to be shipped (see Table 6) would be'subcritical under thcee conditions.
DLH:sgf Attachments
[/N 1637.170
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J. K. PRICE DPSP-79-71-6 References 1.
D. L. Dunaway, " Safety Analysis Report For Packaging, Steel Banded Wooden Shi ping Containers For Slightly Enriched Uranium Metal,p' NLCO-1107, National Lead Company of Ohio, July 1974.
2.
Certificate of Compliance No. USA /5467/AF(ERDA-OR),
Revision No. 3, NLO Wooden Containers, September 20,1976.
3.
H. K. Clark, " Computer Codes for Nuclear Criticality Safety Calculations," DP-1121, November 1967.
4.
H. K. Clark, " Comparison of VE Experiments and Calculations," DPST-63-297, June 12, 1963.
5.
D. L. Honkonen, " Nuclear Safety Criteria for Unirradia-4 ted Mark V-R," RTR-794, Dec. 16, 1965.
6.
Memo D. L. Honkonen to R. H. Dietz, R. M. Radford, and T. L. Evans, " Nuclear Criticality Safety Analysis No. 15, Revised Mark 15 Development Program," June 27, 1972.
7.
10 CFR 71 " Packing Of. Radioactive Material For Transport and Transportatios of Radioactive Material Under Certain Conditions."
Section 71.4 0 8.
Ibid., Appendix B.
li537 17.1 DPSP-79-71-6 TABLE 1 NLO BOX CONTENTS MAXIMUM WEIGHT BOX TYPE, PER BOX, POUNDS MATERIAL TYPE NLO DRAWING NO.
NO. PER BOX, MAX.
' N ET GROSS Mark V R inner canned slugs G-4214 105 1070 1125 Mark VR outer canned slugs G-4214 45 650 705 Mark VE inner canned slugs G-4214 105 1010 1065 Mark V E outer canned slugs G-4214 45 610 665 Mark 15 inner bare cores G-4292*
60 980 1080 Mark 15 inner canned slugs G-4292
- 60 1015 1115 Mark 15 outer bare cores G-4292
- 30 580 680 Mark 15 outer canned slugs G-4292
- 30 610 710
- A wooden false bottom will be placed in each box to reduce the inside useable height from 16 1/8 to 11 1/2 inches.
.35 1637 172
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i TABLE 2 DESCRIPTION OF SLIGHTLY ENRICHED URANIUM SLUGS NOMINAL DIMENSIONS, INCllES MATERIAL TYPE 2350 Content,WT %
CLAD,*GD Bare,** OD BARE,** ID CLAD,* ID BARE ** LENGTH CLAD
- LENGTH
}brk VR outer 0.86 1 0.006 3.074 3.016 2.460 2.402 8.442 8.840 Mark VR inner 0.86 1 0.006 1.972 1.914 1.226 1.168 8.442 8.840 Mark VE outer 0.947 1 0.006 3.076 3.016 2.460 2.400 8.030 8.400 Mark VE inner 0.947 1 0.006 1.974 1.914 1.226 1.166 8.04'O 8.400 Mark 15 outer 1.100 1 0.006 3.700 3.640 3.165 3.105 11.11 11.5 tbrk 15 inner 1.100 1 0.006 2.665 2.605 2.018 1.958 11.11 11.5
- Canned slugs are clad with aluminum
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Led DPSP-79-11-6 TABLE 3 CRITICAL AND SAFE
- MASSES OF MARK VE CANNED SLUGS IN A SQUARE LATTICE IN H O 2
I H 0/y TONS OF U TYPE 2
SLUG TYPE FLOODING PITCH,IN.
u Critical Safe
- Inner Full
+
-1.97 1.0 38.7 15.4 2.13 1.5 7.4 4.6 2.32 2.0 5.2 3.4 2.50 2.5 8.5 4.7 Outer Full 3.08 2.75 475 25.6 3.18 3.00 242 21.4 3.27 3.25 376 22.2 Corresponds to a keff = 0.98.
The smallest of these values is the maximum safe mass.
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e DPSP-79-71-6 TABLE 4 Critical and Safe
- Masses of Mark VR Canned Slugs in Square Lattice in H2O Tons of U Lattice VH02 /Vu Critical Safe
- Type Slug Type Flooding Pitch, in.
Inner Full 1.99 1.158 43.7 16.4 2.04 1.282 28.1 12.3 2.23 1.757 13.2 7.0 2.32 2.012 13.6 6.9 2.42 2.278 17.8 8.1 2.61 2.843 409.5 25.3 Outer Between Slugs 3.19 1.161 56.8 30.0 (axial cavity 3.29 1.424 34.9 19.8 void) 3.39 1.694 28.7 16.3 3.58 2.263 72.3 26.7 Corresponds to a k,ff = 0.98.
The smallest of these values is the maximum safe mass.
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DPSP-79-71-6 TABLE 5 Critical and. Safe
- Masses of Mark 15 Bare Cores in Sauare Lattice in H2O Lattice V
Safe
- H02 /Vu Mass Tons of U Type Core Type Flooding Pitch, in.
Inner Full 2.605 2.19 1.48 2.692 2.40 1.42 2.846 2.80 1.34 2.920 3.00 1.36 3.062 3.40 1.49 3.131 3.60 1.63 3.455 4.60 4.39 Outer Between Cores 3.770 1.50 6.10 (anial cavity 3.935 2.00 4.45 void) 4.000 2.20 4.24 4.062 2.40 4.19 4.124 2.60 4.29 4.245 3.00 4.99 Corresponds to a keff = 0.98.
The smallest of these values is the maximum safe mass.
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DPSP-79-71-6 TABLE 6
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Shipping Limits for Slightly Enriched Uranium Maximum Amount of Piece Designation Type Uranium per Shipment, Tons Mark VR Canned Slugs Inner 6.9 Outer 16.3 Mark VE Canned Slugs Inner 3.4 Outer 3.4 Mark 15 Bare Cores &
Inner 1.3 canned slugs Outer 4.1 e.3 n
.L i o 'q 4 1637 177 DPSP-79-71-6 TABLE 7 Maximum-Safe
- Thickness of An Infinite, Fully Water Reflected Slab Maximum Safe
- Slab Actual Slab Material Type Type Flooding Thickness, in.
Thickness,in.
Mark VE inner canned slugs Full 17.4 8.04 outer canned slugs Between slugs 17.4 8.03 (axial cavity void)
Mark VR inner canned slugs Full 21.7 8.44 outer canned slugs Between slugs 34.0 8.44 (axial cavity void)
Mark 15 inner bare cores Full 12.3 11.11 canned slugs 13.1 11.11 outer bare cores Between cores 22.1 11.11 canned slugs (axial cavity 23.1 11.11 void)
- Corresponds to a keff = 0.98 1637 178
.