Patent Application
20230268094
This invention relates to containing radioactive waste and more particularly this invention relates to a closure means and method for isolating waste in a radioactive material packaging.
Improper disposal of disused radiological sealed sources used by the oil and gas industry, manufacturing, medicine, research, academic institutions, and even government entities continues to have severe environmental and therefore health ramifications. Sealed sources will eventually reach a point where they are no longer usable for their intended purpose, after which they need to be removed, temporarily stored, transported, and ultimately disposed of in a licensed radioactive waste site.
In general, the higher the level of radioactivity in the sealed source, the stricter the regulatory control that should be applied to its use, control, and ultimate disposition. However, lack of control and oversight can and do lead to sources ending up in the wrong place, for example, as orphan sources in uncontrolled storage, disposed in a sanitary landfill, melted down in metal recycling operations and/or incorporated into consumer products.
Furthermore, these sources may be handled by an unsuspecting member of the public. There have been many publicized events during which sealed sources were lost or stolen that resulted in serious injuries and death to unsuspecting members of the public, and massive economic loss, particularly over concerns of potential malicious use by terrorists as radioactive dispersion devices.
Many factors contribute to this problem, but in many cases, lack of availability of certified Type B transportation packaging is a barrier to the safe and secure management of disused radiological sealed sources. A Type B package design must not only demonstrate its ability to withstand tests simulating normal shipping conditions, but must also withstand a sequential set of severe accident conditions without releasing its contents, considering an environmental temperature range of minus 20° F. to plus 100° F. These severe accident conditions include the following:
A need exists in the art for a system and method for safely sequestering radioactive waste in Type B transportation packages. The system and method should enable loading and unloading of waste into a hinged-lid containment vessel (HLCV) in confined spaces and either dry or wet. The system and method should also permit self-alignment and uniform sealing between the HLCV lid and the containment vessel (CV) body.
An object of the invention is to provide a system and method for isolating material in HLCVs that overcomes many of the drawbacks of the prior art.
Another object of the invention is to provide a system and method for hermetically sealing radioactive waste in HCLVs of a Type B transportation package. A feature of the invention comprises a CV lid having a double hinge. An advantage of the invention is that the double hinge permits self-alignment and uniform sealing between the lid and the CV body.
Briefly, the invention provides a containment structure, the containment structure comprising a vessel with an upwardly facing opening defining a periphery; a lid in rotatable and slidable communication with the periphery; and a plurality of rods contained within the lid and in slidable communication with the periphery.
Also provided is a method for sealing and unsealing a HLCV defining a body with a longitudinal axis and a lid, the method comprising simultaneously moving the lid parallel to the longitudinal axis and orthogonal to the longitudinal axis.
The invention together with the above and other objects and advantages will be best understood from the following detailed description of the preferred embodiment of the invention shown in the accompanying drawings, wherein:
The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings.
All numeric values are herein assumed to be modified by the term “about”, whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (e.g., having the same function or result). In many instances, the terms “about” may include numbers that are rounded to the nearest significant figure.
The recitation of numerical ranges by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).
The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.
As used herein, an element or step recited in the singular and preceded with the word “a” or “an” should be understood as not excluding plural said elements or steps, unless such exclusion is explicitly stated. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.
Furthermore, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property.
Both Government and industry, domestic and international, have potential uses of this invention. The inventors at Argonne National Laboratory have developed a new compact Type B transportation packaging, designated as Model 9602, for storage, transport, and disposal of disused radiological sources. The new Type B package's stainless steel structural components are designed to provide long-term performance against corrosion during dry storage (more than 50 years); thus, it may be possible to transport the package directly to a disposal facility without repackaging.
The invented Model 9602 compact Type B package design with HLCV is the only one providing a holistic solution for end-of-life management of disused radiological sources that can be used for transportation, long term storage (>50 years), and final disposal. Significant advantages of the Model 9602 package design with HLCV are compact in dimensions, lightweight, easy to handle and simple loading/unloading of contents, low cost, and amenable to high-volume production.
This invention comprises a CV closure design for containment vessels of a Type B transportation package of radioactive material (RAM). While the illustrations show a vessel with a circular cross section, other shapes (square, polygonal, spheroid, etc., may be accommodated. The invented system is depicted as numeral 10 in
The lid 14 rotatably and simultaneously slidably communicates with a periphery defined by the opening of the CV body 12 via a double hinge system 16. The lid has a circular periphery to complementarily nest within a periphery defining the opening of the CV body 12. The periphery is circumscribed by a flanged collar 13 which is a radially directed portion of the CV body. As such the flanged collar 13 defines a cantilevered ridge which projects over the remaining longitudinally extending exterior surface of the cylinder. Regions of the lid define a radially projected portion 17, the underside of which attaches to and is flush with a surface defined by structures of the double hinge 16. The hinge 16 itself is fastened to a notched portion of the aforementioned flange so as to enable the hinge to be countersunk relative to an upwardly facing surface of the flanged collar 13.
The closure lid 14 is connected to the CV body 12 through the double hinge 16, with locking mechanisms provided by a lid-cap and latch-rod subassemblies. The subassemblies comprise guide pins and springs for closing and opening of the hinged-lid CV (HLCV) by application of an external load.
Loading and unloading of radioactive material or other type contents into the HLCV can be accomplished in confined spaces either dry, as, for example, in a mobile hot cell, or wet, as in a pool.
A version of the HLCV may be used in conjunction with other elements of the Model 9602 compact Type B package design for end-of-life management of disused radiological sealed sources. It may also be used in transportation of reactor- and accelerator-generated radioisotopes.
The double hinge 16 permits automatic self-alignment and uniform sealing between the HLCV lid and the CV body 12. As such, this self-alignment can be done remotely, i.e., via robotics such that constant human intervention is not required to assure accurate lid placement. The lid simultaneously aligns and contacts an opening defined by the HLCV without manually imposing a continuous force on the lid.
The double hinge 16 comprises a first substrate 18 rotatably attached to a second substrate 20. The first substrate 18 defines an upwardly facing flat surface 22 which is attached to and flush with an underside surface of the radially projecting region 17 of the lid 14.
A second feature comprises the first substrate 18 slidably communicating with the second substrate 20 in a direction generally perpendicular to the longitudinal axes of the two substrates. This sliding action is facilitated by a first region of the first substrate 18 opposing and contacting a second region of the second substrate 20. Both the first and second regions form surfaces resembling a sine wave such that both regions have a concave portion 22 integrally molded with a convex portion 24.
The first region of the first substrate 18 and the second region of the second substrate each comprise two convex portions 24 which flank a rod 26 disposed between each pair of convex portions such that the rod is in rotatable communication with its flanking convex portions. As such, each rod is positioned between two convex portions. (In typical hinge hardware parlance, the convex portions may be thought of as the knuckles and each of the rods considered the pin.) The rods are rigidly attached to each other via a bridging substrate 28 connecting longitudinally extending and opposing surfaces of the two rods.
When the hinge is in an open configuration (
As the hinge proceeds from an open position (
A center region of the lid defines a reversibly depressable region 30 (
As shown in
In situations where the sealed HLCV are placed on their sides, all of the rods may be positioned flush with or otherwise countersunk with the external surface of the flange to facilitate rolling of the HLCV. Then, some of the rods may be extended to prevent rolling of the HLCV, while the distal tips of the other rods remain flush or countersunk with the exterior surface of the CV flange, this to facilitate close proximity to containers laid on top or to prevent snagging of the HLCV by rigging or other securement vehicles. Extension of some rods but not other rods beyond the periphery of the CV flange may be achieved by initially installing longer rods along peripheral portion of the lid during lid fabrication. Other rod extension means may include an extension adapted to be received by distal ends of some of the rods.
When the center region 30 is withdrawn from its countersunk configuration (
The track pins 50 and guide pin springs 52 are anchored to the underside of the center cap 30 via a track assembly 53. Generally circular in its periphery, the track 53 assembly has two regions: a superior disk-shaped portion referred to herein as a guide disk 54, and a depending tongue portion 58 defining a closed track 62, coaxial to the center of the disk, defining a track adapted to slidably communicate with a superior distal end 59 of a follower 60 described infra.
The guide disk 54 has a cross section that is complementary to the cross section of an inside periphery of the center portion 30 so as to be threadably received by a periphery of an interior void defined by the underside of the center portion 30. The guide disk 54 serves as a track in that it defines regions forming transverse apertures through which the pins 50 and springs 52 extend.
Distal ends 51 of the pins 50 define threads so as to be threadably received by threaded apertures formed in a basement surface of the void space 33 (
The configuration depicted in
A follower 60 and a follower clamping block 56 are utilized to restrain the lid center portion 30 so that the center portion remains in contact with the lid. The follower 60 resembles a crank such that it defines a central region 57 terminating in two opposite extending protuberances such that the protuberances extend at an angle that is generally orthogonal to a longitudinal axis of the central region 57. The follower is arranged so that its longitudinal axis is parallel to the longitudinal axis of the HLCV 12; in this configuration, a first superior protuberance 59 is maintained above a lower inferior protuberance 61. The lower inferior protuberance is anchored to the basement surface 37 of the void space 33. by the follower clamping block 56. Thus, the first superior protuberance is the distal end of the follower and not permanently attached to a similar structure.
As discussed above, the first superior protuberance 59 reversibly nests within the track 62 formed in a laterally facing surface of the depending tongue.
When the lid center portion 30 is in the countersunk configuration (
The outer groove incorporates a non-metallic gasket (e.g. an elastomeric seal such as EPDM) while the inner groove incorporates a metallic seal. The inner metallic seal provides the containment boundary, has a long life and withstands a wide range of environments. The outer elastomeric seal is used during packaging assembly for leak testing of the containment boundary.
A force of between 20 thousand and 60 thousand pounds may be required to hermetically seat the metal and elastomeric seals during sealing of the lid to the CV body. Conversely, that amount of force would also be necessary to remove the lid from the CV body. The force may be applied, either hydraulically or pneumatically, to lid 14. The hydraulic or pneumatic force may be applied directly to lid 14 such that any closure tool physically contacts and forces the lid downwardly. Alternatively, the hydraulic or pneumatic force may be applied to the exterior bottom surface of the CV body while maintaining the closed but not yet sealed CV body in a vise or other restraining means. The aforementioned forces would not be required to activate/deactivate the sealing of the lid to the body such that manually applied force to the center region 30 of the lid from an average person (so between 40 and 100 pounds of force) will actuate the latch rods described above. The rods are provided to maintain the sealing force imposed by the aforementioned metal and elastomeric seals.
In operation, the invented system is placed upon a support surface with its lid 14 in an open position. Material is loaded into the CV body, after which the lid is closed and automatically aligned with the CV body, said closure usually done remotely given the harmful nature of the material. Such remote closure includes a gloved hand (or hands) in conjunction with a glove box or containment room, levers, robotic arms, or a combination of thereof to provide an inertial push on the lid to continue closing.
Visual inspection of the lid is typically made to confirm accurate alignment with the CV body. After such confirmation, a first axial force is applied to the lid, the axial force extending along the longitudinal axis of the CV body. A suitable first force necessary to actuate the metallic seals is applied to assure sealing of the lid to the CV body. The first axial force may be applied to regions of the lid diametrically opposed to the hinge positioned between the lid and the CV body. Alternatively, the first axial force may be applied along the entire periphery of the upwardly facing surface of the lid. The first axial force would not be applied at this juncture to the center of the lid, as depression of the center is associated with the rod actuation action described supra. Such axial force may be directed downwardly so as to be directed toward the bottom of the CV body. Or the first axial force may be directed upwardly so as to be applied from the bottom of the CV body, in which instance upwardly facing, peripheral regions of the lid are secured to both maintain contact of the lid with the seals and also prevent movement of the CV body as such force (e.g., mechanical or pressure) is applied from beneath the CV body.
This first axial force is applied until the metallic seals are actuated. Actuation may be confirmed via leak testing after the outer O-ring is emplaced. Once the metallic seal is actuated, a second axial force is applied to the center of the lid 30 so as to urge the latch rods in a radial direction to mate with the CV body. This second axial force may be applied after the first axial force is applied, or it may be applied simultaneously while the first axial force is maintained. In the later instance, the first seal is maintained until the rods are actuated in a radial direction.
Once the rods are nested into their receiving apertures formed in the CV body, all forces are removed, and the HICV is deemed sealed after passing the leakage test (per ANSI N14-5 2014) for storage, transport, rolling, or other handling.
To unseal the HLCV, axial forces are reapplied in reverse order.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the invention, they are by no means limiting, but are instead exemplary embodiments. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. § 112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” “more than” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. In the same manner, all ratios disclosed herein also include all subratios falling within the broader ratio.
One skilled in the art will also readily recognize that where members are grouped together in a common manner, such as in a Markush group, the present invention encompasses not only the entire group listed as a whole, but each member of the group individually and all possible subgroups of the main group. Accordingly, for all purposes, the present invention encompasses not only the main group, but also the main group absent one or more of the group members. The present invention also envisages the explicit exclusion of one or more of any of the group members in the claimed invention.
This invention was made with government support under Contract No. DE-AC02-06CH11357 awarded by the United States Department of Energy to UChicago Argonne, LLC, operator of Argonne National Laboratory. The government has certain rights in the invention.
