LANL Plutonium Assessment

At the Los Alamos National Laboratory (LANL), low level nuclear waste (LLW) is processed for disposal at the Waste Isolation Pilot Plant. This waste is processed in a glovebox and then placed into a 55 gallon drum and sent to a nondestructive assay (NDA) laboratory to determine if the waste within the drum\u27s reactivity is below 100nCi/g stipulated by the regulation held by the Enviromental Protection Agency (EPA). In several cases every year, the reactivity of the drum is exceeded, thus requiring a costly and dangerous procedural deviation to divide the contents of the drum to reach an acceptable level of radioactivity. To avoid this problem, an in-line waste assay system must be developed to measure specifically plutonium-240 but also must give a possibility of measuring other types of radioactive materials such as Uranium-235. This product must have the ability to be applied to gloveboxes globally. This will require that the device has the capability of assaying a fully loaded 55-gallon drum that is inserted into the glovebox through a penetration in the floor of the glovebox before movement to the NDA laboratory. This assay must be completed within an hour, while maintaining an ergonomically efficient design. To satisfy these requirements, the goal was to take a neutron counting system available on the market and develop a mechanized collar to hold these devices while it assays the drum\u27s waste underneath the glovebox. The neutron counter that will be applied to the design is Canberra Industries\u27 model JCC-71,72, and 73 [2] accompanied with the JR-14 shift register [3] and neutron counting software [4]. The main aspect of the design will be the development of a mechanized collar operating underneath the glovebox around the floor penetration to safely assay the waste in 2-3 sections on the drum. This will require the collar to have a vertical drive mechanism, a controls component and the construction of a holding rack for the counting slabs. The design will accompany the 6 He-3 slabs fashioned around the drum with one of the holding positions having the ability to accompany a passive or active slab depending on the application desired. The design will include a minimal amount of areas with hard to clean spaces. This design will accomplish all of the specifications explained above and hope to make the operations at nuclear processing facilities more efficient

Safety and safeguards by design - Glove box in-line waste assay system

The work discussed in this paper focuses on creating a device for processing low-level nuclear waste produced from glove box operations on plutonium as well as improving the process to undertake this task. Clean up items such wipes and rags are contaminated with plutonium during the normal operations. Assaying of waster drums is currently performed after the drums are filled with contaminated waste items. As a result, it is possible that a waste drum may contain more than allowable limits of radioactivity. In such cases, the drum contents must be unloaded into additional drums to distribute the radioactivity to the allowable limits per drum. In this work we have analyzed the current process and developed and designed a new device for online assaying of glove box waste drums. By monitoring the radioactivity levels per drum during glove box operations, we have mitigated the possibility of overloading a drum beyond the allowable activity levels. The mechanical operation of the device was tested and proved to meet design and customer specifications. Suitable radiation detectors were researched and selected for compatibility with the mechanical automation device and desired counting of radioactivity