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Chan S.,International Nuclear Services | Harvey J.,NDA Radioactive Waste Management Direc.
Packaging, Transport, Storage and Security of Radioactive Material | Year: 2014

The Radioactive Waste Management Directorate (RWMD) of the UK's Nuclear Decommissioning Authority (NDAi) has responsibility for planning and implementing a Geological Disposal Facility (GDF) in the UK. The responsibility for demonstrating and providing a safe transport operation will be shared between a number of organisations acting as consignors, carriers and the consignee (the GDF operator). The radioactive waste transport system is national in scope. Its main objective is to deliver packaged waste to a facility for disposal in a manner that is safe, secure, planned, timely, cost effective, flexible, environmentally sound and robust against future changes. To fully appreciate the implications for ensuring transport safety a better understanding of the range of options for a GDF transport system is required. One extreme, the current planning assumption in the UK is that each waste producer (consignor) is individually responsible for organising their own transport to a GDF. The other extreme is where a single organisation is responsible for the provision of the transport system (an integrated transport service). Intermediate options will exist where the actual implementation could be anywhere on the scale between the two extremes. A fundamental issue for a GDF transport system for the delivery of Intermediate Level Waste (ILW), High Level Waste (HLW) and spent fuel is the timescale between initial waste packing and final sentencing to the repository. ILW, HLW and spent fuel will need to be managed until a GDF is available and delivery is confirmed. The timescales could be over 65 years given current assumptions. This paper reviews the feasibility of an integrated transport service for the delivery of ILW, HLW and spent fuel to a GDF. It defines the key elements of the integrated transport service, highlighting the advantages and disadvantages. Finally, it sets out the key considerations to be addressed during packing of wastes which will not be transported for up to 65 years. © W. S. Maney & Son Ltd 2014.

Purcell P.C.,International Nuclear Services | Carr N.,Radioactive Waste Management Ltd
Packaging, Transport, Storage and Security of Radioactive Material | Year: 2014

Radioactive Waste Management Limited (RWM) of the Nuclear Decommissioning Authority (NDA) is developing concepts to demonstrate the viability of using a standardised range of disposal canister (DC) designs for geological disposal of high level waste and spent fuel in the UK. The standardised DC are designed for disposal in a geological disposal facility with integrity requirements in the range 10 000 to 100 000 years. International Nuclear Services (INS) is also a subsidiary of the NDA and working with RWM to develop a design of packaging for transporting these DC, which is called the disposal canister transport container (DCTC). Initial studies undertaken by INS focused on optimising payload and geometry for the canister designs. Subsequent studies focused on achieving criticality safety requirements for transport, which established the use of multiple water barriers, were required for higher enriched spent fuels. The results of this initial work were presented at the International Nuclear Engineering society conference at London in 2012. Subsequently, RWM commissioned INS to develop the design of DCTC to a level where it would be viable for licensing as a transport package with appropriate level of technical understanding. A specific requirement of RWM was that the loaded DCTC should be capable of transportation on an existing design of four axle rail wagon, within a gross mass of 90 t, this giving considerable logistic and overall cost benefits. Recent development work has focused on detailed impact, thermal and shielding analysis and how these influence the DCTC transport mass and the position of that mass in relation to the four axle rail wagon, both of which influence its capability for the required transport. In terms of meeting mass limits, achieving the specified radiation shielding performance (neutron and gamma) for the spent fuel was found to be a major challenge. However, of equal challenge was to accommodate the high forces generated under impact accident conditions due to the high mass ratio of contents to container. In order to mitigate these forces, the shock absorber designs needed to be carefully judged because their dimensions were restricted by the rail wagon design. This paper describes the DCTC development work, how the design challenges were addressed and the conclusions reached. © W. S. Maney & Son Ltd 2014.

Acker B.,International Nuclear Services
Packaging, Transport, Storage and Security of Radioactive Material | Year: 2013

The decommissioning and clean-up of the UK's nuclear legacy generates unique transport and package requirements that need to be managed appropriately to minimise their impact. The movement of category I material (transport of plutonium, 20% or above enriched uranium and/or U233 above the regulatory limit) is being considered within the Nuclear Decommissioning Authority estate to consolidate the storage locations and to minimise security costs. To facilitate this, the International Nuclear Services is considering the feasibility and business case for the development of a new package that could increase transport efficiency, enhance safety and represent best value for the UK taxpayer. The 3578 transport package concept has been developed to meet the requirements and constraints of multiple users, in respect of geometry, operator dose uptake, handling procedures and interfaces. It offers a double containment system and incorporates high safety margins. The design has been optimised to take account of as many product types as possible. This approach means that the package can be considered for both on site and off site movement. Owing to its flexible handling arrangements and transport capability, and its simple loading/unloading procedure, the 3578 can be readily used in most nuclear facilities worldwide. The 3578 concept benefits from .20 years' experience of design, manufacturing and operation of radioactive material containers in the UK and around the world. © 2013 W. S. Maney & Son Ltd.

Cummings A.D.,International Nuclear Services | Krywonos J.,International Nuclear Services | Purcell P.,International Nuclear Services | Rothwell G.,Liverpool John Moores University | Matthews C.,Liverpool John Moores University
Packaging, Transport, Storage and Security of Radioactive Material | Year: 2013

The design and development of nuclear packages is critical for the safe transportation of new fuel and irradiated waste. The renaissance of the nuclear industry in recent years has increased motivation for the development of optimised transport and storage solutions. The design of mechanisms to safely constrain nuclear packages, commonly referred to as tie down systems, has become more challenging as package masses have increased. This paper focuses on characterising the loading environment that a tie down system is subjected to using signal processing techniques on previously measured acceleration and strain time histories. The measurements were taken on a tie down system for a nuclear package, weighing 99·7 tonnes, during a routine rail journey. Similar previous studies on tie downs have omitted frequency analysis of the measured signals on tie down systems. A frequency analysis has been used to determine the nature of the loading experienced by a tie down system and also the extent of vibration transmission into the package. A means for obtaining a suitable filter cutoff frequency is also presented by comparing frequency spectra from different measurement points. To extract quasi-static accelerations from the raw data, several digital filters have been designed to study their effects on the resulting signals. By comparing the low pass and band pass filtered time histories, some insightful trends in the accelerations peaks have been found. To demonstrate what constitutes a good or bad filter design, sensitivity studies have been conducted to show how the distributions of peaks and their statistics are altered significantly with poorer filter choices. © 2013 W. S. Maney & Son Ltd.

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