Modelling Radionuclide Transport in Cracks Through Cemented Radioactive Waste

1994 ◽  
Vol 353 ◽  
Author(s):  
A. V. Chambers
Keyword(s):  
Radioactive Waste ◽  
Computer Programs ◽  
Intermediate Level ◽  
Radionuclide Transport ◽  
Intermediate Level Radioactive Waste ◽  
The Uk ◽  
Radionuclide Release

AbstractIt is currently proposed to site the UK repository for intermediate-level radioactive waste (ILW) underground at a depth of several hundred metres, and to use a cementitious backfill to fill spaces between disposal packages within the repository vaults. Flow of water through the repository could be concentrated within cracks that may form in the backfill. This paper describes the CRACK and CRACK2 computer programs. These are used to predict radionuclide release via cracks, and radionuclide distributions within the vault. The programs are applied to an assessment of the release of inventory- and solubility-limited radionuclides from hypothetical ILW vaults. Calculations are reported for different densities of cracking, and for different repository designs, and the dominant modes of transport within cracks in repository vaults are discussed.

The Management of Historic Intermediate Level Radioactive Waste in the United Kingdom

2003 ◽  
Author(s):  
David Horsley ◽  
Bruce McKirdy
Keyword(s):  
United Kingdom ◽  
Radioactive Waste ◽  
Waste Management ◽  
Storage Conditions ◽  
Intermediate Level ◽  
The United Kingdom ◽  
Environmentally Sound ◽  
Intermediate Level Radioactive Waste ◽  
The Uk

Nirex is the organisation responsible for long-term radioactive waste management in the UK. Our Mission is to provide the UK with safe, environmentally sound and publicly acceptable options for the long-term management of radioactive materials. The United Kingdom has a significant legacy of long-lived intermediate level radioactive waste. This has arisen from 50 years of investigation and exploitation of nuclear technology. Some of the waste is stored in old facilities that do not provide the standards of containment that would be incorporated in modern facilities. Also the risk to people and to the environment from the inventory in these facilities will increase with time as the structures age and degrade, increasing the chance of containment failure. There is, therefore, a need to retrieve this raw waste and process and package it to make it demonstrably safe for continued storage, pending a decision on disposal of radioactive waste. This packaging should, as far as is practicable, be compatible with the UK long-term waste management strategy. Nirex has developed its Phased Disposal Concept for intermediate and low-level radioactive waste. Based on that concept, Nirex has developed waste package specifications and carries out assessments of waste packaging proposals. For legacy wastes it may not always practicable to demonstrate full compliance with all Nirex disposal criteria. This paper describes an approach, agreed between Nirex and BNFL, for managing these wastes. The proposed approach takes account of long-term waste management issues whilst recognising the need for timely improvement of storage conditions.

The Assessment of the Performance of the Engineered Barriers in a Repository for the Disposal of Low- and Intermediate-Level Radioactive Waste

1991 ◽  
Vol 257 ◽  
Author(s):  
A. Atkinson ◽  
A.W. Harris ◽  
C.C. Naish ◽  
S.M. Sharland ◽  
A.C. Smith
Keyword(s):  
Radioactive Waste ◽  
Intermediate Level ◽  
Uniform Corrosion ◽  
Short Term ◽  
Deep Underground ◽  
Ph Conditions ◽  
Engineered Barriers ◽  
Intermediate Level Radioactive Waste ◽  
Radionuclide Release ◽  
Modelling Approach

ABSTRACTCurrent plans for the disposal of low- and intermediate-level radioactive waste in the U.K. comprise emplacement of steel or concrete containers of waste in a deep underground repository where they will be surrounded by a cementitious backfill. Research is in progress to assess the effectiveness of steel and concrete as barriers to radionuclide release from the repository. A joint experimental and modelling approach is used. Studies of the transport properties of dissolved radionuclides and gases through concrete, and the ability of the concrete to control the pH in the repository are described. Localised and uniform corrosion of carbon and stainless steels are investigated in the high pH conditions of the repository. The research shows that engineered barriers of concrete and steel can provide useful physical containment in the short term and contribute to chemical containment for hundreds of thousands of years.

An Integrated Safety Assessment System for Near-Surface Disposal of Low- and Intermediate-Level Radioactive Waste in Korea

2003 ◽  
Author(s):  
JooWan Park ◽  
Chang-Lak Kim ◽  
Jin Beak Park ◽  
Eun Yong Lee ◽  
Youn Myoung Lee ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Safety Assessment ◽  
Assessment System ◽  
Intermediate Level ◽  
Radioactive Waste Disposal ◽  
System Level ◽  
Assessment Methodology ◽  
Regulatory Requirements ◽  
Near Surface ◽  
Intermediate Level Radioactive Waste

An integrated safety assessment system to be used for evaluation of near-surface disposal concept has been developed within the framework of safety assessment methodology taken for low- and intermediate-level radioactive waste disposal in Korea. It is to provide an evaluation of the safety of the disposal system in a clear, comprehensive and well-documented manner, and to integrate the results into a defensible package showing reasonable assurance of compliance with regulatory requirements for licensing application. This system is made up of two key components, a system-level safety assessment code and an input database/quality assurance module for safety assessment, which both are interfaced with each other.

Assessment of Package Performance During Long-Term Storage of Intermediate-Level Radioactive Waste

2003 ◽  
Author(s):  
A. V. Chambers ◽  
W. R. Rodwell ◽  
M. Kelly ◽  
A. R. Hoch ◽  
A. J. Baker
Keyword(s):  
Extended Period ◽  
Intermediate Level ◽  
Passive Safety ◽  
Long Term Storage ◽  
Waste Storage ◽  
Disposal Option ◽  
Intermediate Level Radioactive Waste ◽  
The Uk ◽  
The Impact

In the UK, the need for the long-term management of intermediate-level radioactive wastes arises from the absence of an established deep disposal option. As a consequence there is a requirement to demonstrate the ‘passive safety’ of waste packages in stores over a necessarily lengthy period (perhaps 150 years or more). ‘Passive safety’ is taken here to imply that the waste packages themselves would remain safe without intervention; it is assumed however, that the store building and associated infrastructure would need to be actively maintained and that the store may need to be ventilated. Importantly, methods for waste storage also need to ensure that possible future options for disposal are not foreclosed. An extended period of storage suggests that emphasis will need to be placed by waste producers on understanding a number of issues such as: • the impact of corrosion on container integrity; • the assessment of container vents and other features as a pathway for the release of radioactivity; • the extent to which wastes are conditioned for storage and the selection of appropriate methods; • the generation and behaviour of toxic or flammable gases in the storage facility; and the mitigating steps that might be needed to address adverse impacts (e.g. the type of ventilation that the store requires). In this paper, we review the requirements and current state of knowledge relevant to the assessment of operational releases of radioactive, flammable and toxic gases from wastes in long-term interim storage.

Measurement Methodology for Fulfilling of Waste Acceptance Criteria for Low and Intermediate Level Radioactive Waste in Storages

2011 ◽  
Author(s):  
M. Sokcic-Kostic ◽  
F. Langer ◽  
R. Schultheis
Keyword(s):  
Radioactive Waste ◽  
Waste Treatment ◽  
Storage Period ◽  
Intermediate Level ◽  
Acceptance Criteria ◽  
Waste Storage ◽  
Measurement Methodology ◽  
Treatment Facilities ◽  
Intermediate Level Radioactive Waste ◽  
Radioactive Waste Storage

Low and intermediate level radioactive waste must be sorted and treated before it can be sent to radioactive waste storage. The waste must fulfil an extensive amount of acceptance criteria (WAC) to guarantee a safe storage period. NUKEM Technologies has a broad experience with the building and management of radioactive waste treatment facilities and has developed methods and equipment to produce the waste packages and to gather all the required information.

Commercialization Project of Ulchin Vitrification

2010 ◽  
Author(s):  
Hyun-Jun Jo ◽  
Cheon-Woo Kim ◽  
Tae-Won Hwang
Keyword(s):  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Cold Test ◽  
Intermediate Level ◽  
Performance Tests ◽  
Cold Crucible ◽  
Commercial Operation ◽  
Intermediate Level Radioactive Waste ◽  
Hot Test

The Ulchin Vitrification Facility (UVF), to be used for the vitirification of low- and intermediate-level radioactive waste (LILW) generated by nuclear power plants (NPPs), is the world’s first commercial facility using Cold Crucible Induction Melter (CCIM) technology. The construction of the facility was begun in 2005 and was completed in 2007. From December 2007 to September 2009, all key performance tests, such as the system functional test, the cold test, the hot test, and the real waste test, were successfully carried out. The UVF commenced commercial operation in October 2009 for the vitrification of radioactive waste.

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