The present review volume not only covers a wide range of topics pertinent to nuclear science and technology, but has attracted a distinguished international authorship, for which the editors are grateful. The opening review by Drs. Janet Tawn and Richard Wakeford addresses the difficult matter of questioning sci- tific hypotheses in a court of law. The United Kingdom experienced a substantial nuclear accident in the 1950s in the form of the Windscale Pile fire. This in itself had both good and bad consequences; the setting up of a licensing authority to ensure nuclear safety was one, the understandable public sentiment concerning nuclear power (despite the fire occurring in a weapons pile) the other. Windscale today is subsumed in the reprocessing plant at Sellafield operated by British Nuclear Fuels plc and it was inevitable perhaps that when an excess cluster of childhood leukaemia was observed in the nearby village of Seascale that public concern should be promoted by the media, leading to the hearing of a claim of compensation brought on behalf of two of the families of BNFLs workers who had suffered that loss. The review article demonstrates the complexity of und- standing such a claim against the statistical fluctuations inherent and shows how the courts were persuaded of the need to propose a biological mechanism if responsibility were to be held. The Company were undoubtedly relieved by the finding.

Some countries have moved beyond the design and operation of nuclear electricity generating systems to confronting the issue of nuclear waste disposal, whole others are still committed to further nuclear facility construction. Volume 24 chronicles these key developments and examines nuclear reactor accidents at Chernobyl, Bhopal, and TMI. The text also analyzes current international knowledge of neutron interactions; deterministic methods based on mean values for assessing radiation distributions; practical applications of the TIBERE models to explicit computation of leakage terms in realistic reactor geometry; and a technique to deal with the issues of finance, risk assessment, and public perception.

Since its initiation in 1962, this series has presented authoritative reviews of the most important developments in nuclear science and engineering, from both theoretical and applied perspectives. In addition, many original contributions are included.

The editors have pleasure in presenting this volume of our review series. We have specialised in three areas: perturbation Monte Carlo, non-linear kinetics and the transfer of radioactive fluids in rocks. These contributions are linked, however, in the demands for optimising complex systems that are a feature of the scale of nuclear power production. Kuniharu Kishida's account of Japanese thinking in the application of modern non-linear theory to reactor kinetics and control comes at a time when the community of control scholars is seeking how to apply the new ideas that have led to the prominence of chaos theory to our field. Pr- lems of maintenance in power reactors are as severe as ever and must be solved for credibility to characterise any new program. As much as 30% of unanticipated down-time, for example, is due to the failure of motor op- ated valves. We need a theory to provide for preventive maintenance. This in turn depends heavily on on-line monitoring to anticipate failure as well as expert systems to schedule preventive treatment. Noise theory with its promise of on-line interpretation of information from inchoate breakdown is the key. It is all too likely that the need to deal with major departures makes a non-linear theory of noise essential. We can be grateful that P- fessor Kishida has provided us with such a consistent account.

Dur previous volume 14 was devoted to an exposition of the topics of sensitivity analysis and uncertainty theory with its development and application in nuclear reactor physics at the heart of the discussion. In this volume, we return to our customary format as a selection of topics of current interest, authored by those working in the field. These topics range from the theoretical underpinnings of the (linear) Boltzmann transport equation to a resume of our ex pectations in what still may be thought of as twenty-first century technology, the world's fusion reactor program. In the first article of this volume, we have Protopop escu's analysis of the structure of the Boltzmann equation and its solutions for energy and space-dependent problems of an eigenvalue nature. There long has been a curious "folk history" effect in this area~ Wigner and Weinberg could de scribe it as "what was generally known was generally untrue". This account of the Boltzmann equation surely will show that a rigorous basis for our expectations of certain solutions can be well-founded on analysis. Ely Gelbard's review of the methods of determining diffusion-type parameters in complex geometries where simple diffusion theory would be welcome has required just as much rigor to determine how such modeling can be made accurate, although to a more immediate and practical purpose. The two articles can be seen as interesting contrasts, facets of the same underlying problem showing apparently different aspects of the same central core.

The Editors take pleasure in presenting Volume 13 of this annual review series, consisting, as usual, of author itative reviews of timely developments in the technical fields of nuclear engineering, science, and teechnology. No one in the community we try to serve in a post Harrisburg era will need convincing of the relevance of the first two items to be mentioned from the volume. Instru mentation for two-phase flow measurements, by Banerjee and Lahey, has applicability in the engineering research labor atory and to power reactors; the U. S. LWR still remains the dominant power reactor type and seems likely to retain its hold if only through the capital of existing plants this century. Messrs. Bohm, Closs, and Kuhn, however, have a longer time scale to respect as they view for us the prospects of nuclear waste disposal from a European viewpoint. They bring out nicely the political aspects that cannot be divorced from technical considerations in this area, or in the more militant terms of confrontation, in this arena, perhaps. We are pleased to carry in this volume two complemen tary papers on mathematical methods in nuclear engineering."

The Editors have pleasure in presenting a further volume in the se ries to our international audience. Perhaps the most significant event of the passing year has been the publication by the IAEA of its study of the prob lem of continuing radiation protection in the lands surrounding Chernobyl. The major international project undertaken in 1990 and reported in 1991 is worth reading, not only for its assessment of how radiation protection intervention should be applied de facto in accident conditions, but equally for its account of the modern view of the philosophy of radiation protection. Some would, however, wish to argue that the acknowledgement by Iraq of its three-pronged development of nuclear weapons in conditions of secrecy and antagonism was equally significant and indeed as much a deter minant of the future of peaceful nuclear power as the Chernobyl accident. But it must be clear that the developments of weapons and electricity pro duction are not inescapably bound together; the Iraqi weapons program was not linked to any peaceful power development.

Our volume in the annual review series on this occasion represents a departure from our usual practice in that it serves as a Festschrift for Eugene Wigner. Dr. Wigner has won many honours in his long, wide ranging and distinguished career spanning so many upheavals in civilized life. The editors and the authors, indeed the whole nuclear engineering community, will wish to join in a modest but further acknowledgement of the contributions he has made to nuclear engineering, not least to the morality and professionalism of nuclear engineering in a year that has raised such international concerns over safety. It suffices to make a bald statement of Eugene Wigner's life and times here, for the first article of the volume is a loving appreciation by his long-time colleague, Alvin Weinberg, an evaluation of his contribution historically during and after the Second World War but equally an account of the philosophy which Wigner provided to the burgeoning profession. Eugene Wigner was born 17th November, 1902 in Budapest, Hungary and his early schooling is described by Dr. Weinberg.

John Maynard Keynes is credited with the aphorism that the long-term view in economics must be taken in the light that "in the long-term we are aU dead". It is not in any spirit of gloom however that we invite our readers of the sixteenth volume in the review series, Advances in Nuclear Science and Technology, to take a long view. The two principal roles of nuclear energy lie in the military sphere - not addressed as such in this serie- in the sphere of the centralised production of power, and chiefly electricity generation. The immediate need for this latter has receded in the current era of restricted economies, vanishing growth rates and occasional surpluses of oil on the spot markets of the world. Nuclear energy has its most important role as an insurance against the hard times to come. But will the demand come at a time when the current reactors with their heavy use of natural uranium feed stocks are to be used or in an era where other aspects of the fuel supply must be exploited? The time scale is sufficiently uncertain and the duration of the demand so unascertainable that a sensible forward policy must anticipate that by the time the major demand comes, the reasonably available natural uranium may have been largely consumed in the poor convertors of the current thermal fission programme.

Since its initiation in 1962, this series has presented authoritative reviews of the most important developments in nuclear science and engineering, from both theoretical and applied perspectives. In addition, many original contributions are included.

The present review volume not only covers a wide range of topics pertinent to nuclear science and technology, but has attracted a distinguished international authorship, for which the editors are grateful. The opening review by Drs. Janet Tawn and Richard Wakeford addresses the difficult matter of questioning sci- tific hypotheses in a court of law. The United Kingdom experienced a substantial nuclear accident in the 1950s in the form of the Windscale Pile fire. This in itself had both good and bad consequences; the setting up of a licensing authority to ensure nuclear safety was one, the understandable public sentiment concerning nuclear power (despite the fire occurring in a weapons pile) the other. Windscale today is subsumed in the reprocessing plant at Sellafield operated by British Nuclear Fuels plc and it was inevitable perhaps that when an excess cluster of childhood leukaemia was observed in the nearby village of Seascale that public concern should be promoted by the media, leading to the hearing of a claim of compensation brought on behalf of two of the families of BNFLs workers who had suffered that loss. The review article demonstrates the complexity of und- standing such a claim against the statistical fluctuations inherent and shows how the courts were persuaded of the need to propose a biological mechanism if responsibility were to be held. The Company were undoubtedly relieved by the finding.

Some countries have moved beyond the design and operation of nuclear electricity generating systems to confronting the issue of nuclear waste disposal, whole others are still committed to further nuclear facility construction. Volume 24 chronicles these key developments and examines nuclear reactor accidents at Chernobyl, Bhopal, and TMI. The text also analyzes current international knowledge of neutron interactions; deterministic methods based on mean values for assessing radiation distributions; practical applications of the TIBERE models to explicit computation of leakage terms in realistic reactor geometry; and a technique to deal with the issues of finance, risk assessment, and public perception.

Some countries have moved beyond the design and operation of nuclear electricity generating systems to confronting the issue of nuclear waste disposal, whole others are still committed to further nuclear facility construction. Volume 24 chronicles these key developments and examines nuclear reactor accidents at Chernobyl, Bhopal, and TMI. The text also analyzes current international knowledge of neutron interactions; deterministic methods based on mean values for assessing radiation distributions; practical applications of the TIBERE models to explicit computation of leakage terms in realistic reactor geometry; and a technique to deal with the issues of finance, risk assessment, and public perception.

High Energy Electron Beam Irradiation of Water, Wastewater and Sludge; C.N. Kurucz, et al.. Introduction. Electron Beam Technology. Aqueous Chemistry of High Energy Electrons. Disinfection of Wastewater Effluents. Irradiation of Toxic Organic Chemical in Aqueous Solutions. Gamma Irradiation Versus Electron Beam Irradiation. XRay Photon Spectroscopy Calculations; J.E. Fernandez, V.G. Molinari. Introduction. Relevant Aspects of Photon Interactions with Matter. Time-Independent Photon Transport Equation. Solution in a Half Space: Multiple Scattering Effects. Multiple Scattering Effects in the Characteristic Lines. Multiple Scattering of the Rayleigh and Compton Effects. Monte Carlo Methods in Advanced Computer Architectures; W.R. Martin. Introduction. Advanced Computer Architectures. Monte Carlo on Advanced Computer Architectures. Monte Carlo on Parallel Architectures. The WienerHermite Functional Method of Representing Random Noise and its Application to Point Reactor Kinetics Driven by Random Reactivity Fluctuations; K. Behringer. The WeinerHermite Functional Method. Application to Point Reactor Kinetics Driven by Random Reactivity Fluctuations. Index.