Reinforced Radiological Containment Bag

Patent metadata

Field	Value
Publication number	US-2016180979-A1
Application number	US-201414573499-A
Country	US
Kind code	A1
Filing date	Dec 17, 2014
Priority date	Dec 17, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

Radiological containment bags for use in storing alpha particle emitting waste are described. The radiological containment bags are formed of a multilayer film with an inner layer of the film being a sacrificial layer that lies between the interior of the bag and a structural polymeric layer. The sacrificial layer includes a flexible composite material that in turn includes a polymeric matrix and an alpha particle energy absorber incorporated in the polymeric matrix. The sacrificial layer can include a chromophore that can detect early degradation of the sacrificial material.

First claim

1 . A flexible composite material, the flexible composite material including a polymeric matrix and an alpha particle energy absorber incorporated in the polymeric matrix.

2 . The flexible composite material of claim 1 , the alpha particle energy absorber including a conjugated ring system comprising at least two conjugated rings.

3 . The flexible composite material of claim 1 , wherein the alpha particle energy absorber comprises a chromophore, the photonic emission characteristics and/or the color of the alpha particle energy absorber varying in a detectable fashion upon degradation of the sacrificial layer.

4 . The flexible composite material of claim 3 , wherein the chromophore comprises a substituted or unsubstituted phenyl group, a substituted or unsubstituted anthracyl group, a substituted or unsubstituted phenanthryl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted heterocyclic ring, or combinations thereof.

5 . The flexible composite material of claim 3 , wherein the chromophore comprises one or more of anthracene, tetracene, pentacene, naphthodiothiophene, or anthradithiophene, or combinations thereof.

6 . The flexible composite material of claim 1 , comprising a second alpha particle energy absorber.

7 . The flexible composite material of claim 1 , the flexible composite material having a net positive charge.

8 . The radiological containment bag of claim 30 , the polymeric layer comprising a polyurethane, a polyolefin, a polyvinyl chloride, or a blend or copolymer thereof.

9 . The radiological containment bag of claim 30 , the polymeric layer comprising polyethylene.

10 . The radiological containment bag of claim 30 , the polymeric layer comprising a colorant.

11 . The radiological containment bag of claim 10 , the polymeric layer comprising a yellow colorant,

12 . The radiological containment bag of claim 30 , the polymeric layer and the polymeric matrix comprising the same polymer.

13 . The flexible composite material of claim 1 , the polymeric matrix comprising a polyvinyl alcohol.

14 . The flexible composite material of claim 1 , the alpha particle energy absorber having an electron density of about 3.0×10 23 electrons per cubic centimeter or greater.

15 . The flexible composite material of claim 1 , wherein the alpha particle energy absorber comprises a carbon nanostructure.

16 . The flexible composite material of claim 15 , wherein the carbon nanostructure comprises a fullerene, graphene, carbon nanotube, or elemental carbon.

17 . The flexible composite material of claim 16 , wherein the fullerene is C 60 .

18 . The radiological containment bag of claim 30 , the multilayer film further comprising a detection layer, the detection layer being closer to the outer surface of the multilayer film as compared to the polymeric layer, the detection layer comprising a chromophore, the photonic emission characteristics and/or the color of the chromophore varying in a detectable fashion upon degradation of the detection layer.

19 . The radiological containment bag of claim 18 , wherein the chromophore comprises substituted or unsubstituted phenyl, substituted or unsubstituted anthracyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted naphthyl, substituted or unsubstituted heterocyclic rings, or combinations thereof.

20 . The radiological containment bag of claim 18 , wherein the detection layer is continuous or discontinuous across a surface of the polymeric layer.

21 . A method for forming a radiological containment bag, the method comprising:
combining a polymer with an alpha particle energy absorber to form a composite material; applying the composite material to a surface of a polymeric layer to form a multilayer film including a sacrificial layer on the surface of the polymeric layer, the sacrificial layer comprising the composite material; and manipulating the multilayer film to form a radiological containment bag, the multilayer film being manipulated such that the multilayer film has an inner surface facing an interior of the radiological containment bag and has an opposite outer surface, the sacrificial layer being closer to the inner surface as compared to the polymeric layer.

22 . The method of claim 2 wherein the composite material is co-extruded with the polymeric layer.

23 . The method of claim 21 , wherein the composite material is applied to the polymeric layer as a solution.

24 . The method of claim 21 , wherein the alpha particle energy absorber comprises a chromophore.

25 . The method of claim 21 , further comprising forming a detection layer on a second surface of the polymeric layer, the detection layer comprising a chromophore, the detection layer being closer to the outer surface of the multilayer polymer film as compared to the polymeric layer upon formation of the radiological containment bag.

26 . A method for storing radiological materials, the method comprising:
placing radiological materials in a containment bag defining an interior, the radiological materials comprising alpha particle emitting materials, the containment bag comprising a multilayer film including a sacrificial layer and a polymeric layer, the sacrificial layer being closer to the interior of the containment bag as compared to the polymeric layer, the sacrificial layer comprising an alpha particle energy absorber, at least one layer of the multilayer film comprising a chromophore, the chromophore exhibiting a detectable variation in photonic emission characteristics and/or color upon degradation of the at least one layer due to alpha particle emission by the radiological materials; and monitoring the containment bag for the detectable variation in the photonic emission characteristics.

27 . The method of claim 26 , wherein the at least one layer comprises the sacrificial layer.

28 . The method of claim 26 , wherein the alpha particle energy absorber comprises the chromophore.

29 . The method of claim 26 , the multilayer film further comprising a detection layer, wherein the at least one layer comprises the detection layer.

30 . A radiological containment bag comprising the flexible composite material of claim 1 , the flexible composite material being a component of a multilayer film, the multilayer film having an inner surface and an opposite outer surface, the inner surface facing the interior of the containment bag, the multilayer film including a polymeric layer and a sacrificial layer, the sacrificial layer being closer to the inner surface of the multilayer film as compared to the polymeric layer, the sacrificial layer including the flexible composite material.

Assignees

• Savannah River Nuclear Solutions Llc

Inventors

• Washington Ii Aaron L
• Serrato Michael G

Classifications

• G21F1/10

  Organic substances; Dispersions in organic carriers · CPC title

• B65D31/04

  with multiple walls (B65D81/3881 takes precedence; for shock absorbing purposes B65D81/03) · CPC title

• B65D85/82

  for poisons · CPC title

• G21F5/015 Primary

  for storing radioactive sources, e.g. source carriers for irradiation units; Radioisotope containers · CPC title