[en] This book covers the basic principles of physics for radiologic technologists, and includes new chapters on ultrasound and magnetic resonance imaging. Coverage includes magnetism, atoms and molecules, chemical elements, interactions with matter, radiation detectors, radiation exposure, light, the radiographic image in motion, image intensification, the x-ray image on film, processing radiographs, protection in diagnostic radiology, the x-ray circuit

[en] Representatives of nearly one-half of the 114 member states of the International Atomic Energy Agency (IAEA), including the United States, have participated in the development of an international nuclear safety conventions proposed multilateral treaty to improve civil nuclear power reactor safety. A preliminary draft of the convention has been developed (referred to as the draft convention for this report), but discussions are continuing, and when the final convention text will be completed and presented to IAEA member states for signature is uncertain. This report responds to the former and current Chairman's request that we provide information on the development of the nuclear safety convention, including a discussion of (1) the draft convention's scope and objectives, (2) how the convention will be implemented and monitored, (3) the views of selected country representatives on what provisions should be included in the draft convention, and (4) the convention's potential benefits and limitations

[en] We respond to comments regarding a previous paper. We conclude that both the coverage and bracketing approaches to statistical sampling are valid and self-consistent. They differ in the underlying probabilistic statement of the criteria. A re-examination of the application of multiple criteria to decision making in nuclear safety leads us to an alternative approach we have called the testing approach. In this approach the physical criteria may be absorbed into a 'black box' in which the code makes calculations and the whole process is treated as a test of a single outcome in non-parametric statistics. Using the testing approach one can determine whether or not computer code outputs simultaneously satisfy a set of physical criteria with 95% confidence that the criteria are satisfied with 95% probability, using only 59 runs. This conclusion is independent of the number of criteria and of any inter-dependencies between the outputs from the code

[en] We apply methods from order statistics to the problem of satisfying regulations that specify individual criteria to be met by each of a number of outputs, k, from a computer code simulating nuclear accidents. The regulations are assumed to apply to an 'extent', γ_k, (such as 95%) of the cumulative probability distribution of each output, k, that is obtained by randomly varying the inputs to the code over their ranges of uncertainty. We use a 'bracketing' approach to obtain expressions for the confidence, β, or probability that these desired extents will be covered in N runs of the code. Detailed results are obtained for k=1,2,3, with equal extents, γ, and are shown to depend on the degree of correlation of the outputs. They reduce to the proper expressions in limiting cases. These limiting cases are also analyzed for an arbitrary number of outputs, k. The bracketing methodology is contrasted with the traditional 'coverage' approach in which the objective is to obtain a range of outputs that enclose a total fraction, γ, of all possible outputs, without regard to the extent of individual outputs. For the case of two outputs we develop an alternate formulation and show that the confidence, β, depends on the degree of correlation between outputs. The alternate formulation reduces to the single output case when the outputs are so well correlated that the coverage criterion is always met in a single run of the code if either output lies beyond an extent γ, it reduces to Wilks' expression for un-correlated variables when the outputs are independent, and it reduces to Wald's result when the outputs are so negatively correlated that the coverage criterion could never be met by the two outputs of a single run of the code. The predictions of both formulations are validated by comparison with Monte Carlo simulations

[en] The Department of Energy's Federal Energy Management Program (FEMP) is considering the development of a technology-specific Super-Energy Saving Performance Contract (ESPC) for water conservation. Prior to the development however, FEMP requires the completion of a market assessment to better understand the water conservation opportunities and the strategies available for capturing them. Thus, this market assessment has been undertaken to evaluate the water conservation opportunities and answer the key questions necessary for FEMP to make recommendations on whether or not to proceed with strategies for water conservation primarily through the development of a water conservation technology-specific performance contract

[en] Several methods (Bayesian, testing, confidence) are presented for evaluating the probability 'p' that the outputs of a computer code, given random inputs, will meet a set of evaluation criteria. They all lead to the same expression for the confidence β that p exceeds some desired value q, based on the results of running the code independently N times. This expression is independent of the number of evaluation criteria. The 'coverage' approach to sampling, which yields a confidence β _co that the extreme values of the outputs from N independent runs of the code bound a region into which a single run of the code will fall with at least a probability γ, is shown to solve a different problem and to be unsuitable as a method for evaluating 'p', except in the special case when there is only one evaluation criterion. The method has broad application. It is developed in this paper in the context of evaluating the likelihood that a nuclear plant will meet the applicable safety criteria

[en] Nuclear reactor regulations in the USA originally specified deterministic criteria to be met by thermal/hydraulic codes. A set of results from a single run of the code was compared with a set of criteria. Codes are now becoming 'realistic' with uncertainties incorporated into the process, usually requiring many runs of the code. The result is a range of results with associated probabilities. Regulations do not currently specify how such results should be evaluated against acceptance criteria. A suggestion has been made to use a level of confidence (e.g., 0.95) that the criteria are satisfied with at least some specified probability (e.g., 0.95). Some valid and invalid ways of doing this and their consequences are presented. It is suggested that an improved process would relate the thermal/hydraulic outputs to measures of core damage or some other suitable measure of risk. Furthermore, the uncertainties modeled in the code should be combined with uncertainties and probabilities, e.g., about functioning of equipment and operator actions, that are now represented in the probabilistic risk assessment (PRA). The task of combining thermal/hydraulic codes with PRA techniques to produce an effective and feasible technology presents a challenge to the technical community

[en] Published in summary form only

[en] Let μ be the self-avoiding walk connective constant on Z^d. We show that the asymptotic expansion for β_c = 1/μ in powers of 1/(2d) satisfies Borel-type bounds. This supports the conjecture that the expansion is Borel summable.

[en] The dynamics following charge transfer to solvent from iodide to a water cluster are studied using time-resolved photoelectron imaging of I^-(H₂O)_n and I^-(D₂O)_n clusters with n≤28. The results show spontaneous conversion, on a time scale of ∼1 ps, from water cluster anions with surface-bound electrons to structures in which the excess electron is more strongly bound and possibly more internalized within the solvent network. The resulting dynamics provide valuable insight into the electron solvation dynamics in water clusters and the relative stabilities between recently observed isomers of water cluster anions