Evolution of the Cavern-Extended Storage (CES) Concept for Flexible Management of HLW

2003 ◽  
Vol 807 ◽  
Author(s):  
Ian G. McKinley ◽  
Fiona B. Neall ◽  
Paul A. Smith ◽  
Julia M. West ◽  
Hideki Kawamura

ABSTRACTThe search for greater public acceptance for radioactive waste disposal has meant that repository planning increasingly includes monitoring, institutional control and flexibility with respect to retrieval and reversability. However, the fundamental repository designs are generally unchanged. This paper describes an alternative – the Cavern Extended Storage concept – which aims to incorporate requirements for flexibility and choice for future generations into a deep geological disposal concept that provides a much safer option than extended surface storage.

Author(s):  
Hiroyoshi Ueda ◽  
Satoru Suzuki ◽  
Katsuhiko Ishiguro ◽  
Kiyoshi Oyamada ◽  
Shoko Yashio ◽  
...  

NUMO (Nuclear Waste Management Organization of Japan) has the responsibility for implementing deep geological disposal of high-level (HLW) and transuranic (TRU) radioactive waste from the Japanese nuclear programme. A formal Requirements Management System (RMS) is planned to efficiently and effectively support the computerised implementation of the management strategy and the methodology required to drive the step-wise siting processes, and the following repository operational phase. The RMS will help in the comprehensive management of the decision-making processes in the geological disposal project, in change management as the disposal system is optimised, in driving projects such as the R&D programme efficiently, and in maintaining structured records regarding past decisions, all of which lead to soundness of the project in terms of long-term continuity. The system is planned to have information handling and management functions using a database that includes the decisions/requirements in the programme under consideration, the way in which these are structured in terms of the decision-making process and other associated information. A two-year development programme is underway to develop and enhance an existing trial RMS to a practical system. Functions for change management, history management and association with the external timeline management system are being implemented in the system development work. The database format is being improved to accommodate the requirements management data relating to the facility design and to safety assessment of the deep geological repository. This paper will present an outline of the development work with examples to demonstrate the system’s practicality. In parallel with the system/database developments, a case research of the use of requirements management in radioactive waste disposal projects was undertaken to identify key issues in the development of an RMS for radioactive waste disposal and specify a number of use cases to guide the overall development of the system. The findings of the case research will also be shown in the paper to provide general information on the application of an RMS in a radioactive waste disposal programme, the difficulties of successful implementation and suggestions on how these difficulties can be overcome.


Author(s):  
Kazumi Kitayama

The programme for disposal of radioactive waste in Japan is now moving ahead on a number of fronts. On the regulatory side, responsibility for TRU waste disposal has been assigned to NUMO and guidelines for the safety goals for disposal of LLW have been published. NUMO, as the implementer for the deep geological disposal programme, has been developing the special tools for project management that are needed as a result of the decision to adopt a volunteering approach to siting. NUMO is also building up the technical infrastructure for flexible tailoring of site characterisation, repository design and the associated safety assessment to the conditions found in any volunteer site. This work requires openness and transparency in decision-making but, as several sites may need to be investigated in parallel, particular emphasis is placed on operational practicality.


2015 ◽  
Vol 79 (6) ◽  
pp. 1265-1274 ◽  
Author(s):  
Timothy A. Marshall ◽  
Katherine Morris ◽  
Gareth T.W. Law ◽  
J. Frederick W. Mosselmans ◽  
Pieter Bots ◽  
...  

AbstractUranium incorporation into magnetite and its behaviour during subsequent oxidation has been investigated at high pH to determine the uranium retention mechanism(s) on formation and oxidative perturbation of magnetite in systems relevant to radioactive waste disposal. Ferrihydrite was exposed to U(VI)aq containing cement leachates (pH 10.5–13.1) and crystallization of magnetite was induced via addition of Fe(II)aq. A combination of XRD, chemical extraction and XAS techniques provided direct evidence that U(VI) was reduced and incorporated into the magnetite structure, possibly as U(V), with a significant fraction recalcitrant to oxidative remobilization. Immobilization of U(VI) by reduction and incorporation into magnetite at high pH, and with significant stability upon reoxidation, has clear and important implications for limiting uranium migration in geological disposal of radioactive wastes.


Author(s):  
Stan Gordelier ◽  
Pa´l Kova´cs

The world is facing energy difficulties for the future, in terms of security of supply and climate change issues. Nuclear power is virtually carbon free and it contributes to energy security, being a quasi-domestic source. Whilst it cannot provide a complete answer to these challenges, it is certainly capable of providing a significant component of the answer. However, nuclear power remains controversial. In order to gain public acceptance, it is widely recognised that a number of key issues need to be addressed, amongst which is resolution of the high-level radioactive waste (HLW) (including spent fuel) disposal issue. This is an important issue for all countries with an existing nuclear programme, whether or not it is intended that nuclear power should be phased out or expanded — the waste already exists and must be managed in any event. It is equally important for countries planning a new nuclear power programme where none has previously existed. Since nuclear power was first developed over fifty years ago, HLW arisings have been stored as an interim measure. It is widely believed by experts (though not by many opponents of the nuclear industry, nor by the public) that deep geological disposal, after a reasonable cooling time in interim storage, is technically feasible and constitutes a safe option [1] at an acceptable cost. The total volume of HLW from nuclear reactors is relatively small. A key issue, however, is the time-scale for developing such a final disposal solution. Considerations of security and inter-generational equity suggest that geological disposal should be implemented as soon as possible irrespective of whether or not new arisings are created. The question of managing HLW is not necessarily related to the issue of building new nuclear power stations. However, many opponents argue that there has been insufficient demonstration of the long-term safety of deep geological disposal. The same opponents also argue that there should be a moratorium on building new nuclear power plants (NPPs) until the issue of long-term management of HLW is resolved. These arguments have a powerful influence on public opinion towards both the construction of a waste repository and the building of new NPPs. The intent of this paper (developed from the current OECD NEA study on “Timing of High Level Waste Disposal”) is to identify and discuss some of the factors influencing the timing of the implementation of a HLW disposal strategy and to demonstrate to decision makers how these factors are affecting country strategies, based on current experience. Determining an optimum timescale of HLW disposal may be affected by a wide range of factors. The study examines how social acceptability, technical soundness, environmental responsibility and economic feasibility impact on the timing of HLW disposal and can be balanced in a national radioactive waste management strategy taking the social, political and economic environment into account. There is clear evidence that significant fractions of the public still have serious misconceptions with respect to the issues surrounding nuclear waste. The nuclear industry, together with governments in those countries who would like a component of nuclear power in their energy mix, has a responsibility for and a significant challenge in presenting its case to the public.


2008 ◽  
Vol 1124 ◽  
Author(s):  
Yasushi Yoshida ◽  
Hideki Yoshikawa

AbstractConcentrations of Ra in groundwater was thought to be affected by substitution reactions with alkaline earth elements contained in a mineral, because the concentration of Ra is less than the solubility of known Ra containing phases. The substitution reaction was simulated using a partition coefficient. Calcite is a dominant mineral to react with Ra in a geological disposal system. However, previous identification of reactive layers of calcite or reversibility of the substitution reaction has not been confirmed. A re-distribution experiment was therefore undertaken and it was found that an estimated 21±13 layers near the surface were reactive and within them substitution equilibrium was achieved. Using these results, a model to estimate Ra concentration was established and adopted to analyze Ra migration. The effects of substitution of Ra and Ca were reasonably simulated.


Author(s):  
P. Marjatta Palmu ◽  
Torsten L. Eng

Several European waste management organizations have started the work on creating a technology platform to accelerate the implementation of deep geological disposal of radioactive waste in Europe. There is an increasing consensus in the international community [1] about geological disposal as the preferred option for solving the long-term management of spent fuel, high-level waste, and other long-lived radioactive wastes. At the same time, the European citizens [2] have a widespread wish for a solution for high-level radioactive waste disposal. A majority of the European countries with nuclear power have active waste management programmes, but the current status and the main challenges of those programmes vary. The most advanced waste management programmes in Europe (i.e. Sweden, Finland and France) are prepared to start the licensing process of deep geological disposal facilities within the next decade. Despite the differences between the timing and the challenges of the different programmes, there is a joint awareness that cooperation on the scientific, technical, and social challenges related to geological disposal is needed, and the cooperation will be beneficial for the timely and safe implementation of the first geological disposal facilities. Such a demonstration of a viable solution for the management of high-level radioactive waste will enhance stakeholder confidence in Europe. Several decades of research, development and demonstration (RD&D) have been carried out in the field of geological disposal. International opportunities of cooperation and establishing a technology platform were explored in the European Commission co-funded projects like Net.Excel [3] and CARD [4]. According to the CARD project, the majority of the funding for RD&D in waste management comes from the implementing organizations. It is envisaged that a technology platform would enhance European cooperation in this area. The platform intends to constitute a tool for reducing overlapping work, to produce savings in total costs of research and implementation, and to make better use of existing competence and research infrastructures. After the final workshop of the CARD project in 2008, SKB (Sweden) and Posiva (Finland) were committed to lead the preparation work to set-up the Implementing Geological Disposal of Radioactive Waste Technology Platform (IGD-TP). Other implementers from France, Germany, Switzerland, Great Britain, Spain, and Belgium joined en suite. A Vision Document for the IGD-TP is about to be finalized after a wider consultation was carried out in July 2009. The final Vision Document and the platform are launched during November 2009. Simultaneously, the preparation of the Strategic Research Agenda for the technology platform’s joint work starts.


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