[en] A brief theoretical introduction to the important physical parameters involved in ionic conduction in solids is followed by order of magnitude estimates of these quantities for materials which can be considered as fast ion conductors. The major part of the review comprises a literature survey of materials which have been studied with a view to fast ion conduction. The significant physical characteristics of these materials are outlined, and conductivity and diffusion data reported where available. These data are coupled with additional technological criteria to indicate which classes of materials are considered worthy of further research. (author)

[en] The in-situ irradiation-induced attenuation of a number of commercially available multimode optical fibres has been studied as a function of temperature and dose-rate using ⁶⁰Co gamma-radiation. Silica fibres doped with germanium and phosphorus exhibited the lowest radiation sensitivity at doses < 10² Gy (10⁴ rads) and plastic clad silica (PCS) fibres at doses greater than this, up to 10⁵ Gy (10⁷ rads). The differences in radiation response for temperatures in the range 0⁰C to 100⁰C and dose-rates of 10²-10³ Gy h^-1 were small. (author)

[en] The UK programme to study fission and corrosion product behaviour in fast reactor sodium cooled system is described. The main topics are: a) the magnitude of material and radioactivity release to the primary coolant and the respective contribution from fuel cladding and structural components. b) the pattern of corrosion product and activity deposition in various parts of the circuit. c) the accuracy of estimates of activity levels deposited on the surfaces of circuit components liable to require maintenance or repair, and associated dose rates. d) the effect of corrosion product deposition on circuit hydraulics and heat transfer

[en] In the United Kingdom, the focus for work on deep geological disposal has been on intermediate level waste (ILW) from nuclear power plants and from the reprocessing of spent nuclear fuel (TRU waste). There is some discussion of the UK programme but then a broadening to consider the views and needs of implementers dealing with all types of long-lived waste worldwide. (author)

[en] The possibility of repository overpressurization was considered in Nirex 97. The calculated overpressures are assessed to be too low to give rise to significant deleterious effects on the repository system in terms of cracking. Although a number of toxic gases, such as hydrogen sulphide may be generated in the repository, it is considered that they will react with the materials in the repository, and therefore no toxic hazards will arise in the biosphere. The possibility that flammable mixtures will form in surface engineered structures has been considered. It is assessed that flammable mixtures of gases are extremely unlikely to form in engineered structures at the surface, above a repository, even in the event of a highly focused discharge. (author)

[en] This abstract summarises the issues identified at the workshop 'Regulating the Long-term Safety of Radioactive Waste Disposal' held in Cordoba, Spain under the auspices of the three NEA committees, the RWMC, the CRPPH and the CNRA in early 1997. The workshop attracted high-level representatives of policy-making bodies, regulators and implementers and had the benefit of a live case study in the certification process for the US-DOE WIPP facility. The workshop was structured around three interfacing themes that are relevant to the topic, viz: - Radioactive waste disposal criteria. - Performance assessment. - Regulatory review process. Rapporteurs analysed the presentations and discussions at the workshop according to this structure to identify outstanding issues. This paper seeks to record the issues identified in a factual and objective manner, trying to avoid any re-interpretation. (author)

[en] In 1997, the UK programme for the deep disposal of radioactive waste was ''stopped dead in its tracks'' with the refusal by the Secretary of State for the Environment to allow Nirex to go ahead with its plans for an underground Rock Characterisation Facility at Sellafield in north-west England. Since that time a House of Lords' Select Committee has held an inquiry into what went wrong and what the way ahead should be. In addition, Nirex and the nuclear industry players have also been analyzing the past with a view to learning from the experience in taking things forward. In Nirex's view this is essentially an ethical issue; the waste exists and we should deal with it in this generation. Three areas need to be better addressed if a successful program of management of the nation's radioactive waste is to be achieved: the process of how policy development and implementation can be achieved; the structure of the nuclear industry and its relationship to the waste management organization; and the behavior of the players in their interaction with stakeholders. All three are underpinned by the need for transparency. In recognition that developing a policy for managing radioactive waste has to be achieved with the support of all stakeholders, the Government instigated a consultation exercise in September 2001. The initial phase of this initiative is essentially a consultation about consultation and is intended to decide on how the next stages of a six year policy development program should be addressed. In addition to this exercise, the Government is undertaking a fundamental review of the structuring of the United Kingdom Atomic Energy Authority (UKAEA) and British Nuclear Fuels plc (BNFL). They are both shareholders in Nirex and in November 2001 the Government announced the setting up of a Liabilities Management Authority (LMA) to manage the long-term nuclear liabilities that are publicly owned, particularly through those organizations. The future of Nirex will be directly influenced by the outcome of these reviews

[en] The lessons learned are presented and problems are identified in making a case for the long-term safety of the deep geological disposal of the United Kingdom's inventory of intermediate-level and certain low-level radioactive wastes. The discussed topics include assessment of the risks, the evaluation at critical groups or potentially exposed groups, the timescale for assessment and the use of Probabilistic Safety Assessment. (R.P.)

[en] There is considerable current interest in the development of advanced rechargeable lithium batteries containing ionically conducting solid polymeric electrolytes. The cathodes in some of these batteries consist of an electroactive material embedded in a matrix of electrolyte to form a flexible film. Typically, the cathode materials are insertion compounds such as V/sub 6/O/sub 13/ or TiS/sub 2/ and the electrolytes are combinations of poly(ethyleneoxide), PEO and lithium salts such as lithium trifluoromethanesulphonate, LiCF/sub 3/SO/sub 3/. The aim of this work was to gain an increased understanding of the cathode region of solid state batteries of the type Li/PEO/sub n/:LiCF/sub 3/SO/sub 3//V/sub 6/O/sub 13/. The cathode region typically consists of 45% by volume of the elecrochemically active material, V/sub 6/O/sub 13/ and 5% of acetylene black in particulate form, together with 50% of an ionically conducting matrix of PEO/sub 9.0/:LiCF/sub 3/SO/sub 3/. It was hoped that a better characterisation of the cathode region, particularly its morphology, would enable important aspects of the problem of loss of battery capacity with usage to be effectively addressed. Results are reported of SEM/EDX, polarising microscopy and complex impedance conductivity studies of the influence of morphology on the behaviour of thin polymeric catholyte films

[en] The results of a UK-based industrial consorium, aimed at the development of high-t_c superconducting wores, tapes and bulk conductors are reviewed in this paper. The powder-in-tube method has been used to fabricate 10's of meter lengths of bismuth-based, Ag-clad, single and multifilamentary wires. Performance highlights include current densities of 23,000 angstrom cm^-2 (7A) at 77K. Bulk ceramic processing techniques, sol-gel chemsitry and plasma-spraying have also been used to fabricate a range YBCO and bismuth-based components. Currents in excess of 100 angstrom have been carried in bulk 2223 bismuth-based samples at 77K