INTEGRATED TRANSPORT SYSTEM FOR NUCLEAR FUEL ASSEMBLIES

• US 3,732,427 A
• Filed: 03/17/1971
• Issued: 05/08/1973
• Est. Priority Date: 03/17/1971
• Status: Expired due to Term

• Current Assignee: Arthur G. Trudeau, Darrow F. Haagensen
• Original Assignee: Arthur G. Trudeau, Darrow F. Haagensen
• Inventors: Trudeau, Arthur G., Haagensen, Darrow F.
• Primary Examiner(s): Borchelt, Archie R.
• Application Number:
  US05/125,259
• Time in Patent Office: 783 Days
• Field of Search: 250/16R,16S,18R 105/1,366 280/29,443 303/21CE,21CF 340/48,52
• US Class Current: 250/505.1
• CPC Class Codes: G21F 5/14 Devices for handling containers or shipping-casks, e.g. transporting devices loading and unloading, filling of containers cranes, load-engaging elements or devices for cranes, capstans, winches or tackles B66C

Abstract

A transport system for conveying nuclear fuel assemblies from a nuclear power plant to a plant for reprocessing or to a burial ground comprising a unique two part shipping cask and a trailer transporter for the cask or casks, constructed on the single spar concept. The novel cask as well as the transporter are constructed with fast neutron as well as gamma ray attenuation materials thereby providing adequate shielding for the formidable array of radiation emitted by spent fuel assemblies used in recent advanced light water converter reactors as well as first generation fast breeder reactors. The trailer transporter may be interchangeably wheeled for transit over conventional roadways or railways, or a modified rail car may be provided onto which the entire cask and trailer transporter may be loaded. A plurality of such cars so loaded form a unit train, having a locomotive to haul the train and a control car immediately therebehind to monitor heat, radiation and stress parameters of each loaded car making up the unit train.

Claims

1. An integrated nuclear fuel transport system for transporting a nuclear fuel assembly including fuel rods in a basket or the like comprising:

a. A primary cask sub-assembly having radiation shielding within its walls for receiving a fuel assembly including nuclear fuel rods in a basket or the like;

b. A secondary cask assembly having radiation and thermal energy shielding within its walls, for receiving said primary cask sub-assembly, said primary cask sub-assembly being separable therefrom; and

c. A trailer transporter having at least one support bay therein integrally receiving said secondary cask assembly having said primary cask sub-assembly therewithin.

2. The invention as recited in claim 1, wherein said primary cask sub-assembly comprises:

a. An inner shell of structurally rigid material serving as a hopper for a spent nuclear fuel assembly having a plurality nuclear fuel rods;

b. An intermediate shell of radiation absorbing material; and

c. An outer cladding of structurally rigid material encasing said intermediate shell.

3. The invention as recited in claim 2, wherein both said inner shell and outer cladding are made of stainless steel.

4. The invention as recited in claim 2, wherein said intermediate shell is made of uranium.

5. The invention as recited in claim 1, wherein said secondary cask assembly comprises:

a. An inner shell of structurally rigid material serving as a hopper for said primary cask sub-assembly;

b. A shield of hydrogenous material adjacent said secondary cask inner shell for attenuating neutron emissions from spontaneously fissionable transuranium elements;

c. A shield of gamma ray, alpha particle and beta particle absorbing material adjacent said hydrogenous material shield for attenuating emissions caused by radioactive decay; and

d. An outer cladding of structurally rigid material encasing said gamma ray shield.

6. The invention as recited in claim 5, wherein said secondary cask further comprises an intermediate shell of structurally rigid material interposed between said hydrogenous material shield and said gamma ray shield.

7. The invention as recited in claim 6, wherein said secondary cask inner shell, outer cladding, and intermediate shell are made of stainless steel.

8. The invention as recited in claim 5, wherein said gamma ray shield is made of uranium.

9. The invention as recited in claim 5, wherein said hydrogenous material comprises wet plaster.

10. The invention as recited in claim 1, wherein said trailer transporter comprises:

a. A substantially vertically disposed elongate support spar running the length of said transporter;

b. A substantially horizontal floor mounted on top of said support spar;

c. At least one secondary cask support bay integrally mounted therein aDjacent the junction of said support spar and floor, beneath said floor; and

d. At least one pair of wheel support means located at corners of said transporter.

11. The invention as recited in claim 10, wherein said transporter includes a pair of secondary cask support bays, one to each side of said support spar beneath said floor.

12. The invention as recited in claim 10, wherein each of said secondary cask support bays further comprises an external circulating cooling system for dissipating thermal energy emitted from said secondary cask.

13. The invention as recited in claim 10, wherein said trailer transporter further comprises:

a. A pair of elongate structural side wall means interconnecting the outer longitudinal edges of said floor and the base of said support spar; and

b. A plurality of support blocks disposed along at least one of said side wall means for supporting said secondary cask support bay along the length thereof.

14. The invention as recited in claim 13, wherein a space defined by said floor, side wall means, support bay and support spar is filled with hydrogenous material.

15. The invention as recited in claim 14, wherein said floor includes a hydrogenous material supply tank mounted thereupon, communicated to said space through check valve means.

16. The invention as recited in claim 14, wherein said hydrogenous material filled space includes at least one layer of gamma ray absorbing material interposed therein.

17. The invention as recited in claim 16, wherein each of said support blocks includes a layer of gamma ray absorbing material interposed therein.

18. The invention as recited in claim 14, wherein said space filling hydrogenous material comprises paraffin.

19. The invention as recited in claim 14, wherein said space filling hydrogenous material comprises wet plaster.

20. The invention as recited in claim 14, wherein said space filling hydrogenous material comprises water.

21. The invention as recited in claim 10, wherein said floor includes an interposed layer of radiation shielding.

22. The invention as recited in claim 10, wherein said transporter further comprises a semi-cylindrical personnel shield mounted over said floor.

23. The invention as recited in claim 10, wherein said wheel supports are four in number, one at each corner of said trailer transporter, each wheel support including:

a. A removable axle bracket; and

b. A wheel mounted on said axle bracket.

24. The invention as recited in claim 23, wherein said wheels include a logic circuitry controlled braking system comprising:

a. Braking means on each wheel;

b. Sensing means on each wheel reading the rotational speed thereof;

c. Logic circuitry means for reading and comparing data from the sensing means with a programmed reference speed; and

d. Control means from the logic circuitry means to the braking means applying braking power to each wheel in response to impulses from said logic circuitry means.

25. The invention as recited in claim 1, wherein said integrated nuclear fuel transport system further comprises a railroad car having an internal upwardly facing configuration conforming to the underside configuration of said trailer transporter for removably slidably receiving said trailer transporter thereon.

26. The invention as recited in claim 25, wherein said integrated nuclear fuel transport system further comprises a unit train having:

a. Locomotive means for the train;

b. A plurality of said railroad cars each having said trailer transporter thereon; and

c. A control car interposed between said locomotive means and said plurality of railroad cars, for monitoring and recording at least thermal, radiation and pressure parameters of each transporter loaded railroad car.

27. A nuclear fuel cask assembly for a nuclear fuel assembly including fuel rods in a basket or the like comprising:

a. A primary cask sub-assembly having radiation absOrbing material in the walls thereof for receiving a nuclear fuel assembly having nuclear fuel rods in a basket or the like therein; and

b. A secondary cask assembly having radiation and thermal energy shielding within its walls, for receiving said primary cask sub-assembly therein, said primary cask sub-assembly being separable therefrom.

28. The invention as recited in claim 27, wherein said primary cask sub-assembly comprises:

a. An inner stainless steel shell arranged as a hopper for a spent nuclear fuel assembly;

b. An intermediate layer of uranium shielding; and

c. An outer cladding of stainless steel, encasing said uranium shielding.

29. The invention as recited in claim 28, wherein said uranium shielding is of substantial thickness with respect to said inner stainless steel shell, said inner shell and outer cladding being approximately equal in thickness.

30. The invention as recited in claim 27, wherein said secondary cask assembly comprises:

a. An inner stainless steel shell arranged to receive said primary cask sub-assembly;

b. A layer of hydrogenous, neutron absorbing and reflecting material surrounding said secondary cask inner shell;

c. Uranium shielding enveloping said secondary cask hydrogenous material; and

d. An outer cladding of stainless steel about said secondary cask uranium shielding.

31. The invention as recited in claim 30, wherein said secondary cask assembly further comprises an intermediate stainless steel shell, interposed between said secondary cask uranium shielding and hydrogenous material.

32. The invention as recited in claim 30, wherein said hydrogenous material is made of water.

33. The invention as recited in claim 30, wherein said hydrogenous material is made of wet plaster.

34. The invention as recited in claim 30, wherein said hydrogenous material is made of paraffin.

35. The invention as recited in claim 30, wherein said hydrogenous material is made of polypropelene plastic.