Treatment consists of operations intended to provide safety or economic benefit by changing the characteristics of the waste. Three basic treatment objectives in waste treatment are:

• Volume reduction (incineration of combustible waste, compaction of solid waste, disassembly of bulky waste components or equipment).

• Removal of radionuclides from the waste (e. g., decontamination, melting of contaminated metal components, evaporation of liquid waste streams and filtration of gaseous waste streams). Decontamination can result in volume reduction by clearing waste or changing waste class to waste with end-point.

• Change of physical or chemical composition of the waste (e. g., solidifica­tion of sediment to enable disposal).

The international nuclear community recognizes the potential of nuclear energy systems to cope with increasing energy demand and international protocol for climate change even after the Fukushima accident. Interna­tional cooperative programmes have been initiated to develop new systems that secure stable energy supply and have improved public acceptance, safety, and cost-effectiveness. The Republic of Korea is actively participat­ing in these programmes currently, such as the Generation IV International Forum (GIF) and the International Project on Innovative Nuclear Reactors and Fuel Cycle (INPRO).

Korea has been a chartered member of GIF since 2000 and plays a sig­nificant role in the development of Gen-IV. GIF was organized for collabo­rative development of new generation nuclear energy systems aiming for 2030 that can be accepted by the public and the energy market with excel­lent technical features and competitive economics, with 13 members leading nuclear utilization and development in the world taking part in GIF. GIF selected six systems of the most promising concepts as the Generation IV nuclear energy systems (Gen-IV) in 2002 and has been conducting collabo­rative R&D for each system through multilateral agreements since 2005. Korea focuses on SFR (sodium-cooled fast reactor-see Fig. 21.10) and

VHTR (very high temperature reactor) among the six Gen-IV systems. SFR is expected to use and recycle uranium resources effectively and mini­mize high-level radioactive waste with proliferation resistant fuel cycles. Korea is participating in six collaborative projects, tackling safety and oper­ation, advanced fuels, and component design and balance of plant in SFR. Korea’s Long-term Development Plan for Future Nuclear Energy Systems, approved in December 2008, also presents a milestone and deliverables of SFR and pyro-processing technology.

KAERI has been developing pyro-processing technology (Fig. 21.10) for recycling useful resources from spent fuel since 1997. The process includes pre-treatment, electro-reduction, electro-refining, electro-winning, and a waste salt treatment system. The removal of transuranic elements (TRU), Cs, and Sr from spent fuel allows the repository burden to be reduced by a factor of 100, compared with the case without removal. Fission products (FP) are recovered and transferred to a repository. As a result of pyro — processing, both repository efficiency and uranium usage are increased up to 100-fold with strong proliferation resistance.

According to the analysis of KAERI, spent nuclear fuel stock at the end of this century can be maintained at a level lower than that of today by introducing SFRs coupled with pyro-processing technology in the 2030s (Fig. 21.11 ).

to be renewed in 2014. In 2008, the IAEA approved an electro­refining laboratory — the Advanced Spent Fuel Conditioning Process Facil­ity (ACPF) at KAERI which is to be built by 2011 and expanded to engineering scale by 2012. This is envisaged as the first stage of a Korea Advanced Pyro-processing Facility (KAPF) to start experimentally in 2021 and become a commercial-scale demonstration plant in 2025. In connection with renewal of the US-ROK agreement in or by 2014, discussions are proceeding on pyro-processing.

High-level radioactive waste

In line with the Specified Radioactive Waste Final Disposal Act, final dis­posal facilities are planned for the geological disposal of HLW and are scheduled to start operation in the 2030s through the following three-step selection process: selection of preliminary investigation areas, selection of detailed investigation areas, and selection of the final disposal facility areas. When local governments wish to volunteer for ‘areas to be investigated as to the feasibility of constructing final repository of HLW’, it is important that the implementor (NUMO), the government and the utility companies give sufficient understanding and awareness to the local residents about the advantages and disadvantages of the final repository and various sectors of the local community, including local government. The government, research and development (R&D) institutions and NUMO, while giving due consid­eration to their own roles and in close partnership, are expected to consist­ently promote R&D into HLW geological disposal. NUMO is expected to safely implement the final HLW disposal project and systematically perform technical development to improve the economics and efficiency of the dis­posal activities. R&D institutions, led by the JAEA, through utilization of underground research facilities, continue to conduct research on under­ground geology, basic R&D towards improved reliability of geological disposal technology and safety assessment methods, and for safety regulations.

While being aware of overseas knowledge and experience, it is important to develop and maintain an advanced knowledge base that supports final repository projects and safety regulations, as well as to appropriately reflect it in NUMO’s final disposal projects. To this end, the government and R&D institutions work together to survey the entire Japanese waste management programme systematically and efficiently. R&D institutions such as JAEA, Radioactive Waste Management Funding and Research Center, etc., need to cooperate with the government and NUMO in activities to improve the understanding and awareness of society at large. Furthermore, it is neces­sary for the government to develop specific rules concerning safety regula­tions based on the progress of these R&D activities.

Geological disposal of radioactive wastes containing transuranium elements

Some LLW containing TRU elements needs to be disposed of geologically. If some TRU waste targeted for geological disposal can be buried together with HLW (co-disposed), the number of repository sites may be reduced, improving economic efficiency. Based on assessment of the influence of TRU and HLW co-disposal on the integrity of the disposal site, the govern­ment should then consider necessary measures, including the nature of an implementing body and its own involvement.

LLW from overseas reprocessing consigned by Japan will gradually be returned from France and the UK. French reprocessing firms suggest chang­ing the solidification method from embedding in bitumen to vitrification, while UK reprocessing companies will embed the LLW in cement for geo­logical or disposal with institutional control. In the latter case, the waste returned to Japan is HLW (vitrified waste) with equivalent levels of radio­activity to the LLW exported. In light of these suggestions, it is expected that the number of shipments can be reduced and storage facilities in Japan for LLW awaiting final disposal can be downsized. Thus, the government, in response to discussions with the operators, will assess the benefits of waste treatment by the new solidification methods, suggested by France, and of the conversion indexes of waste, as suggested by the UK. If these suggestions are found to be acceptable, the government should discuss the institutional issues.

As has been shown in Section 25.2, defence wastes can have an extremely large compositional range, varying from pure metal (i. e., Pu or HEU) through well-defined chemical compounds (e. g., oxides), to the liquid and semi-solid HLW tank wastes found at various separation facilities. Any treatment process must ensure that the ultimate waste form is intrinsically (passively) safe, leach resistant, chemically stable and radiation resistant. The chosen process must also be sufficiently flexible in order to deal with the compositional variability within a waste stream and more significant variations between different varieties of waste stream.

During the Cold War period, the two major protagonists, US and Russia, operated two different philosophies on the value of plutonium which had a significant impact on the inventories of Pu-contaminated wastes and resi­dues requiring disposal (Jardine et al., 1999). Whereas US policy was to establish a Pu concentration for the various wastes and residues below which it was considered more economical to produce new metal (economic discard limit, EDL), Russian policy was to recover all Pu above a concentra­tion of 200 ppm for re-use. To implement this philosophy extensive recovery processes were installed at the Pu production facilities of Mayak, Tomsk and Krasnoyarsk.

In November 2004, in the underground laboratory of Meuse/Haute-Marne, ANDRA reached at 445 m depth, the depth of the clay layer to be studied. The first gallery was dug to install a series of experimental devices. Then the digging of the shafts continued, and at 490 metres, new galleries were dug horizontally and other experiments undertaken. The data collected fully confirmed the results of laboratory research and tests made at Mont Terri in Switzerland.

2005: submission of Dossier

A few months later, ANDRA released the Dossier 2005 (ANDRA, 2005). In 10,000 pages, it compiled 15 years of research. It concluded that the clay layer of the Meuse/Haute-Marne was perfectly suitable for receiving a disposal facility for high — and intermediate-level long-lived radioactive waste. This dossier also contained a description on the interest in granitic formations for geological disposal. A milestone had been reached for the management of radioactive waste in France.

15.3.4 2006-2010

The MRWS programme also takes into consideration some radioactive materials that are not classified as wastes in the UK. These materials include uranium, plutonium and some spent nuclear fuel associated with civil nuclear activities. They have potential value: uranium and plutonium can be used to make nuclear fuel, and spent nuclear fuel can be reprocessed to recover uranium and plutonium for reuse. However, if it was decided at some point in the future, on the basis of economics or environmental and safety issues, that these materials had no further use, they may need to be managed as wastes. Radioactive materials that are not deemed to be waste are not reported in the UK Radioactive Waste Inventory, but summary information is provided in a separate document that is published with the Inventory.

A difficult situation for previous and current owners and operators of Dounreay has been the contamination of Sandside beach neighbouring Dounreay and the immediate foreshore and seabed by radioactive particles (Rodriguez et al., 2005; Rodriguez, 2009). These particles originate from the mechanical cutting operations involved with reprocessing of DMTR fuel and have activities in the range 103-108Bq 137Cs. They are thought to have been unknowingly discharged to sea through the LLLE system during the 1960s and 1970s. The discharges of the particles, although not intended, were nevertheless unauthorised. Although risk studies by UK national institu­tions (Harrison et al. , 2005) indicate there is not a significant risk to the public by the presence of these particles, there is local concern about past discharges and current finds of particles on the publicly accessible beach (208 particles from 1983 to early 2012). The outcome of long-term environ­mental studies, academic reviews and public consultation on how to deal with the problem has been to instigate a programme of recovery of particles in an area of 60 ha of the seabed off Dounreay. The recovery operations are carried out by specialist diving teams using remote controlled seabed vehicles.

TRU waste is managed by the DOE. Defense TRU waste is disposed of in the WIPP geological repository and consists of two types. Remote-handled (RH) TRU waste emits more radiation than contact-handled (CH) TRU waste and must be both handled and transported in shielded casks. Section

18.7.7 provides more details on TRU waste and the WIPP facility.

As described in Section 19.2.2, the Government of Canada is implementing a long-term strategy, the NLLP, to deal with the nuclear legacy liabilities at AECL sites. The program addresses environmental restoration, infrastruc­ture decommissioning, waste management, and care and maintenance of the nuclear liabilities until they are addressed.

An important element of the program is the development of an inte­grated waste plan to ensure the selection of the optimal mix of enabling facilities and their implementation schedules to address the current and future wastes arising from the program ’ s activities. An interim integrated waste plan for CRL has been developed, and will be expanded to the other sites and go through multiple iterations of refinement as additional planning and waste characterization data are obtained.

As input to the refinements of the integrated waste plan, a number of studies are under way to better define the waste processing, treatment and long-term management facilities required to deal with the wide variety of legacy waste types at AECL sites. This will help to define, for example, the volume reduction and waste immobilization technologies to be used, the extent to which buried waste can be managed in place over the long term, and the available options for the long-term management of the waste that needs to be recovered.

Significant savings in long-term waste management costs at CRL could be achieved by constructing a very low level waste (VLLW) facility to receive large volumes of VLLW wastes such as soil, concrete, vegetation, asphalt and/or building materials/rubble that are being generated by NLLP infrastructure decommissioning and environmental remediation projects and activities. All pre-project activities have been completed to support the development of a VLLW facility, and formal project development activities are being initiated.

In 2006, an investigation was initiated to assess the feasibility of the bedrock at the CRL site to host a proposed geological waste management facility (GWMF) as a final enabling facility for the long-term management of low — and intermediate-level solid radioactive waste at the site.

The feasibility study involved exploring the geoscience and engineering characteristics of the proposed bedrock and the drilling and testing of char­acterization boreholes. The collected information and interpretations were then used to construct three-dimensional deterministic computer models of the geology of the site and the associated groundwater flow regime. The results of the feasibility study are currently under review by various parties to assist in the decision-making process for proceeding.

AECL has initiated discussions with the NWMO on the long-term man­agement of AECL’s varied inventory of legacy research reactor fuel waste within the NWMO APM approach.

The Necsa solid waste management system is aimed at providing principles, guidelines and standards that are aligned with sound waste management practices. The system is also aimed at managing the interfaces that exist in terms of the waste management steps and the Necsa organizational structure.

The principles of waste prevention and waste minimization are para­mount in the overall Necsa waste management system. These principles are entrenched in every step of the waste management process, from the point of operations in the various Necsa facilities to the decisions on the options for the management of different waste categories. Although not being taken into account in the past, it is also important to consider waste generation control and minimization during the design phase of future facilities at Necsa. The design of buildings and plant should be such that the minimum amount of waste is generated by the planned activities. This integrated system is shown in Fig. 20.12.

20.1.6 Solid radioactive waste categorization

A system is provided according to which radioactive waste on the Necsa site shall be categorized to enable the identification of waste for subsequent waste management processes. The scheme for the categorization of waste as well as the principles for categorization of radioactive waste is addressed in this systems document.