Package plutonium metal and oxide in flowformed canisters

Abstract

Plutonium metal and oxide are typically handled and processed in isolated enclosures (gloveboxes) and then transferred to storage packing systems. The United States Department of Energy (DOE) outlines general requirements relevant to the planned DOE activities to stabilise and package plutonium materials in containers, and place them in long term storage. Inner and outer containers have been qualified as the primary barrier to the environment during storage of the plutonium materials. The design and fabrication of the containers are consistent across the DOE complex. The flowform manufacturing process has been used for over 20 years to fabricate the weld free, precise containers for several DOE sites meeting ASME section III code, subsection NCA-3851.2 (a)(1).     

Disposal container safety assessment – drop tests with 'Yoyushindo-Disposal' waste container onto concrete target

Abstract

This paper presents technical details of the drop test performance as well as some experimental results of tests carried out with the Japanese 'Yoyushindo-Disposal' waste container for intermediate depth disposal. The drop test program comprised three single 8 m drop tests at the specimen's corner edge orientation onto a concrete slab. The slab was connected to the unyielding IAEA target of the BAM's 200 t drop test facility. The three tested specimens had masses between 20 000 and 28 000 kg depending on their content mass. The tests were accompanied by various metrology, such as strain and deceleration measurements, optical three-dimensional deformation methods, leak tightness testing and test installation for potential particle release measurements to collect a set of data for establishing a basis for safety assessment.     

Thermal analysis of proposed transport cask for three advanced burner reactor used fuel assemblies

Abstract

Preliminary studies of used fuel generated in the US Department of Energy's Advanced Fuel Cycle Initiative have indicated that current used fuel transport casks may be insufficient for the transportation of said fuel. This work considers transport of three 5-year-cooled oxide advanced burner reactor used fuel assemblies with a burn-up of 160 MWD kg^–1. A transport cask designed to carry these assemblies is proposed. This design employs a 7-cm-thick lead gamma shield and a 20-cm-thick NS-4-FR composite neutron shield. The temperature profile within the cask, from its centre to its exterior surface, is determined by two-dimensional computational fluid dynamics simulations of conduction, convection and radiation within the cask. Simulations are performed for a cask with a smooth external surface and various neutron shield thicknesses. Separate simulations are performed for a cask with a corrugated external surface and a neutron shield thickness that satisfies shielding constraints. Resulting temperature profiles indicate that a three-assembly cask with a smooth external surface will meet fuel cladding temperature requirements but will cause outer surface temperatures to exceed the regulatory limit. A cask with a corrugated external surface will not exceed the limits for both the fuel cladding and outer surface temperatures.     

International transport of uranium concentrates

Abstract

There has been discussion within industry for a number of years regarding standards for shipping uranium concentrates from producers (mine/mill operations) to uranium conversion facilities. Although the standard way of transporting ore concentrates is in drums (nominally 200–210 L size), the specific packing and securing methods for sea transport vary considerably. A major initiative was recently launched within the World Nuclear Transport Institute with the setting up of a task force to examine the aspects of the transport of uranium concentrates that include a marine component. These aspects were grouped into three areas of interest as follows: the drums used for packaging, the sea International Standards Organisation (ISO) containers themselves and the restraint of the drums in the ISO containers. The objective of the task force has been to explore the concept of standard good industry practices for uranium concentrates packaging and shipping in ISO containers. Based on the findings of the Task Force, the present paper shares the lessons learned. It discusses good industry practices, which can be used as a basis to establish common methodology for the transport uranium concentrates. It considers the value of adopting a common approach and in this regard, the present paper highlights the current variations in drum design and the range of difficulties this can pose. In addition, the present paper describes drum restraint systems within the container, explaining the way in which securing methods have had to change due to restrictions on the use of wood dunnage. The importance of using containers satisfying ISO 1496 standard and the Convention for Safe Containers is discussed. Based on industry experience, important operational procedures to ensure well packaged secure loads are also discussed.