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Publication numberUS3432666 A
Publication typeGrant
Publication dateMar 11, 1969
Filing dateMar 12, 1965
Priority dateMar 13, 1964
Also published asDE1514957A1, DE1514957B2, DE1514957C3
Publication numberUS 3432666 A, US 3432666A, US-A-3432666, US3432666 A, US3432666A
InventorsGeoffrey James Chetewoode Nash, Keith Harding
Original AssigneeAtomic Energy Authority Uk
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Containers for transporting radioactive and/or fissile materials
US 3432666 A
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Description  (OCR text may contain errors)

March 11, 1969 c, NASH ETAL 3,432,666

CONTAINERS FOR TRANSPORTING RADIOACTIVE AND/OR FISSILE MATERIALS Filed March 12, 1965 United States Patent 10,719/ 64 US. Cl. 250-108 Int. Cl. G21f /00 7 Claims ABSTRACT OF THE DISCLOSURE A transport container for radioactive material comprising a casing which includes a radiation attenuating substance dispersed in a matrix including a moderator material, the substance also affording fire protection for the container. Fire protection is achieved by employing a hydrated salt of boron which absorbs heat as its water of crystallization is driven off through vent holes in a layer surrounding the casing.

This invention relates to containers for use in transporting radioactive and/ or fissile materials.

It has been suggested that an efficient container for transportaation of radioactive materials should withstand a drop test from thirty feet without damage sufficiently severe to cause a release of the contents and a fire test at 800 C. for thirty minutes without appreciable reduction of radiation shielding effect.

Containers so far designed have incorporated steel or lead for gamma attenuation, wood for neutron moderation and cadmium to absorb neutrons.

However, the known arrangement of wood and cadmium is no barrier to fast neutrons originating inside the container.

Additionally, wood gives rise to certain drawbacks in use. Thus, it is of variable density and water content, requires to be fabricated to fit into an outer canister and to receive the isotope vessel. Furthermore, wood is liable to split as it dries out and may give rise to wood acids which could corrode adjacent metals.

It is one object of the present invention to avoid these drawbacks.

According to the present invention a container for use in transporting a radioactive material comprising an inner vessel to receive the radioactive material and a casing surrounding the vessel comprising a neutron moderating substance and a neutron capturing substance uniformly distributed in a matrix of cast plastic material, said casing also affording fire protection to the vessel.

In this arrangement neutrons emitted from fissile material inside or outside the container will be sufliciently moderated by the matrix material for the probability of their capture to be very high.

An embodiment of the invention will now be described, by way only of example, with reference to the accompanying drawing which is a sectional elevation.

In the drawing is shown a transport container having an aluminium vessel 1 for carrying non-irradiated fissile material, with a screw cap or lid 2. The vessel 1 is enclosed in a casing 3 of a mixture of borax and epoxy resin in the weight ratio 1:1. The casing has a lid 4 of the same mixture. The casing is surrounded by a metal layer including a steel canister 5 having a lid 6 with suitably placed vent holes V, the lid 6 being retained in place on the canister 5 by a retaining band 7. The shuttering 8 is 3,432,666 Patented Mar. 11, 1969 provided to define the space in the matrix material for receiving the vessel 1 and the lid 4.

In using the container, the fissile material to be transported is deposited Within the vessel 1 and cap 2, lid 4 and lid 6 are placed in position and secured.

In this arrangement neutrons emitted from fissile material inside or outside the container will be sufiiciently moderated by the hydrogen contained in the borax and resin matrix for the probability of their capture by the boron in the borax present, to be very high.

Borax is used in the above example as a typical hydrated salt. Such salts act to introduce extra hydrogen into the casing as well as absorber atoms. They also serve as heat insulators insofar as they absorb heat in having their water of crystalisation driven off through ventholes V in the casing. Gamma shielding can also be added in the form of a heavy metal or such of its compounds, for example lead chromate, as may conveniently be added to the plastic. The final choice of loading material will depend, for a fissile material container, on the optimum combination of hydrogen and neutron absorber to give a minim-um casing thickness and hence minimum overall size. It is an advantage in utilising a plastic as casing as opposed to wood, in that it can be pumped, whilst liquid, into the canister to fill any cavity so as to surround the vessel and provide a casing of uniform hydrogen and radiation attenuating distribution.

The plastic afiords adequate fire resistance for the contents whilst the steel canister serves mainly as shuttering during the casing and is retained to provide additional impact and abrasion protection to the casing.

We claim:

1. A container for use in transporting radioactive material comprising an inner vessel to receive radioactive material, a means for attenuating radiation and a casing around the vessel comprising a neutron moderating substance and a neutron capturing substance uniformly distributed in a matrix of cast plastic material, and a means, including vents, for venting from said casing water of crystallization derived from said neutron capturing substance of said matrix.

2. A container according to claim 1 wherein said means for attenuating radiation includes a radiation attenuating substance uniformly distributed in said matrix.

3. A container according to claim 2 wherein said radiation attenuating substance is a heavy metal.

4. A container for use in transporting a radioactive material according to claim 1 in which the neutron capturing substance comprises a hydrated salt.

5. A container for use in transporting a radioactive material according to claim 4 in which the hydrated salt is borax.

6. A container according to claim 3 in which the radiation attenuating substance is lead chromate.

7. A container for use in transporting a radioactive material according to claim 4 wherein the casing is mounted in a metal canister which affords impact and abrasion protection to the casing.

References Cited UNITED STATES PATENTS 3,106,535 10/1963 Blanco 250-108 3,114,838 12/1963 Pontet 250-108 X 3,114,839 12/1963 Peters 250-108 3,133,887 5/1964 Alliegro et al. 250-108 3,126,351 3/1964 Blair et al. 250-108 X 3,229,096 1/1966 Bonilla et al. 250-108 ARCHIE R. BORCHELT, Primary Examiner.

US. Cl. X.R. 250-106

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3106535 *Dec 28, 1959Oct 8, 1963Ici LtdNeutron radiation shielding material
US3114838 *Jul 25, 1960Dec 17, 1963Charles Pontet HermannContainers for radioactive isotopes
US3114839 *May 25, 1959Dec 17, 1963Lukens Steel CoRadiation shielding plastic clad
US3126351 *Dec 31, 1958Mar 24, 1964JohnsHydrated lead borate products
US3133887 *Oct 6, 1958May 19, 1964Norton CoNeutron shields and methods of manufacturing them
US3229096 *Apr 3, 1963Jan 11, 1966Nat Lead CoShipping container for spent nuclear reactor fuel elements
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3723742 *Apr 11, 1968Mar 27, 1973Trw IncRadioisotope capsule protection structure
US3749917 *May 12, 1971Jul 31, 1973Kucherer HDevice for encapsulating a radioactive resin-water slurry
US3754141 *Jul 12, 1972Aug 21, 1973Atomic Energy CommissionShipping and storage container for high power density radioactive materials
US3780306 *May 27, 1971Dec 18, 1973Nat Lead CoRadioactive shipping container with neutron and gamma absorbers
US3883742 *Jul 27, 1973May 13, 1975Packard Instrument Co IncScintillation counter, segmented shield
US3886368 *Feb 27, 1973May 27, 1975Nuclear Fuel ServicesSpent fuel shipping cask
US3930166 *Dec 14, 1973Dec 30, 1975Robatel SlpiPackage for transporting or enclosing radioactive materials
US3982134 *Sep 19, 1974Sep 21, 1976Housholder William RShipping container for nuclear fuels
US4022317 *Jul 7, 1975May 10, 1977Kms Fusion, Inc.Package for fragile objects
US4560069 *May 2, 1985Dec 24, 1985Simon B KennethPackage for hazardous materials
US4569818 *Apr 19, 1983Feb 11, 1986Deutsche Gesellschaft Fur Wiederaufarbeitung Von Kernbrennstoffen MbhIrradiated reactor fuel elements
US4588088 *Jan 10, 1983May 13, 1986Allen Arthur AContainer assembly for storing toxic material
US4595112 *Jul 12, 1984Jun 17, 1986Greif Bros. CorporationThermal container
US4747512 *Jun 19, 1987May 31, 1988Lo Kin KTransportation packaging for liquids
US4752437 *Dec 4, 1985Jun 21, 1988Kabushiki Kaisha Kobe Seiko ShoPackaging of radioactive materials
US4846235 *Jun 9, 1987Jul 11, 1989Halliburton CompanyRadioactivity shielding transportation assembly
US4869299 *Oct 11, 1988Sep 26, 1989Halliburton CompanyRadioactivity shielding transportation assembly and method
US4880119 *Jun 24, 1988Nov 14, 1989Simon B KennethCushioned container for hazardous material
US5008084 *Aug 13, 1990Apr 16, 1991Instruments for Research and Industry I2 R, Inc.Keeping biological samples cold after transfer from a freezer to work place
US5303836 *Jul 21, 1993Apr 19, 1994The Babcock & Wilcox CompanyShipping container for highly enriched uranium
US5337917 *Mar 2, 1993Aug 16, 1994Sandia CorporationCrash resistant container
US5995573 *Sep 18, 1997Nov 30, 1999Murray, Jr.; Holt A.Dry storage arrangement for spent nuclear fuel containers
US6230877 *Mar 12, 1999May 15, 2001Team Safepac I Karlskoga AbSafety packaging
EP0036961A2 *Mar 5, 1981Oct 7, 1981Forschungszentrum Jülich GmbhContainer for storing tritium
WO1995013617A1 *Nov 10, 1993May 18, 1995American Intercontinental InveRadioattenuant composition, method and container
Classifications
U.S. Classification250/506.1, 976/DIG.343, 220/560.1, 206/527, 376/272, 206/524.1, 220/62.11, 220/902, 206/523
International ClassificationG21F5/005
Cooperative ClassificationY10S220/902, G21F5/005
European ClassificationG21F5/005