WO1997022125B1

WO1997022125B1 - Radiation shielding

Info

Publication number: WO1997022125B1
Application number: PCT/US1996/019507
Authority: WO
Filing date: 1996-12-06
Publication date: 1997-08-21

Abstract

A radiation shield (10), and a radiation shield assembly. The shield assembly is designed to allow use of conveniently fabricated radiation shield portions (S1(1), S1(2), S1(3)) to provide a single completed radiation shield (10). The shield portions are mechanically fastened together, preferably with deck screws (22). A completed radiation shield assembly is coated with a flexible elastomeric epoxy coating (30) to protect the radiation shielding material, preferably lead, from becoming dislodged. Preferably, the radiation shield is provided in a sequence of layers, with each layer having one or more radiation shield portions. In an alternate embodiment, a lightweight, portable radiation shield (40) is provided which has at least one sheet of solid radiation shielding material (S), an outer stainless steel casing (60), and a sealant (74) located between at least portions of the at least one sheet of solid radiation shielding material (S) and the outer stainless steel casing (60). Flanges (64, 66) on the stainless steel casing (60) are fastened together, preferably by riveting to seal the casing. A stainless steel U-shaped cap (80) is provided at the top of the shield (40) for extra protection during use. The sealant (74) and the stainless steel casing (60), including the cap (80), cooperate to effectively seal the solid radiation shielding material (S) against leakage outward through the outer stainless steel casing (60).

Claims

AMENDED CLAIMS [received by the International Bureau on 15 July 1997 (15.07.97); original claim 3 cancelled; original claims 1 and 10 amended; remaining claims unchanged (2 pages)] 1. A layered radiation shield, said layered radiation shield comprising: (a) an inner layer comprising at least one sheet of solid radiation shielding material; and(b) an outer layer comprising a flexible, elastomeric coating, said elastomeric coating resistant to discoloration and coating degredation when said layer is exposed to sunlight, wherein said elastomeric coating has a shore D hardness of at least 37, as measured by ASTM Method D-2240. 2. The radiation shield as set forth in claim 1, wherein said elastomeric coating has a minimum percent; elongation, as measured by ASTM Method D- 838, of sixty percent. 4. The radiation shield as Bet forth in claim 1, wherein said elastomeric coating has a tensile shear strength, as measured by ASTM Method C-1002, of approximately 347 pounds per square inch. 5. The radiation shield as set forth in claim 1, wherein said elastomeric coating comprises a Bisphenol A epoxy coaiing. number of radiation shield layers provided; and wherein in each of said layers S1 through %, one or more shield portions is provided and wherein the number of shield portions in each of said sequence of layers may be described, in sequence, as shield portions SN(1) through SN(X), wherein X is a positive integer corresponding to the number of radiation shield portions in any layer N; and (b) an elastomeric outer coating layer, said elastomeric coating outer layer comprising a flexible, elastomeric coating, said elastomeric coating resistant to discoloration and coating degredation when said layer is exposed to sunlight, wherein said elastomeric coating has a Shore D hardness of at least 37, as measured by ASTM Method D-2240. 11. The radiation shield as set forth in claim 10, wherein the number of radiation shield portions X in any one of said sequence of layers K equals the number of radiation shield portions X in an adjacent layer N-1 therebelow. 12. The radiation shield as set forth in claim 11, wherein the number of layers N is equal to two. 13. The radiation shield as set forth in claim 11, wherein said radiation shield further comprises a pluraliry of mechanical fastenera, and wherein said plurality of mechanical fasteners are adapted to fasten radiation shield portions in said layer SN STATEMENT UNDER ARTICLE 19

1. Claims 1-30 originally were pending in the application.

2. Claims 1 and 10 have been amended.

3. Claims 2, 4-9, and 11-30 have not been amended.

4. Claim 3 has been cancelled.

claims 1 and 10 were amended to include a property of the structure which is novel and which involves an inventive step over prior art of record, namely the feature that in the instant invention, the shield is designed with high Shore D hardnes, to more clearly define the invention over Silivers'her, U.S. Patent No. 2,358,451 , and Herndon et al. U.S. Patent No. 5,139,857 (where the hardness of the coating is not specified).