[en] The Bose-Einstein correlation of π⁰ pairs is studied for the first time at LEP using the L3 detector. An enhancement of π⁰ pair production with similar momentum is observed in the data when compared to Monte Carlo reference samples. Different parameterization schemes to describe the Bose-Einstein effect are examined. The observed correlation is compared with other LEP results

[en] A device that measures charge-exchange flux to determine the angular distribution of the 2XIIB plasma is described. Charge-exchange products heat circular nickel foils (placed at 15⁰ intervals in theta and at constant radius on an arc parallel to the z-axis) and the voltage drop across the foils (produced by constant-current sources) provides a measure of the changes in resistivity. The charge-exchange flux at each foil is proportional to the plasma distribution at that angle. Use of this technique is limited by the resistivity and heat resistance of the circular nickel foils, but could conceivably be extended to other shapes and materials. The Hall-Simonen and ''time-average'' measurement of angular distribution are compared and the characteristic times of loss (gain) are calculated from theory. The g(μ) detector may be used to experimentally verify these times of loss (gain) and also to analyze plasma pressure stability. Current microwave measurements show that plasma has an exponential density dependence in z and assumes a flux tube rather than a p(B) density dependence. A distinct angular distribution (determinable by the detector) is associated with each of these dependencies. The codes to simulate injection and resulting angular distribution, charge-exchange capture, and heating and signal of the detectors are also described

[en] This report describes an investigation into the applicability of high performance liquid chromatographic techniques for the separation of the complex mixtures of organic acids commonly found in groundwaters. This work has shown that reverse phase ion-pair chromatography using a large pore stationary phase can be successfully applied to humic material in both natural and concentrated groundwater from the Drigg Research Site. The methodology separates the organic species into a number of well resolved components the majority of which have a molecular weight of greater than 500 Dalton. Separations obtained have been qualitatively and quantitatively analysed using a Diode array spectrophotometer. The components in excess of 500 Dalton show UV absorption spectra similar to humic and fulvic acids where as the component with a molecular weight of less than 500 Dalton shows a sharp UV absorption cutoff at 230 nm. It was noted that this component was not removed by passage through DEAEA cellulose. Reverse phase HPLC was also investigated, and results were found to be consistent with a separation based on an ion-repulsion/size exclusion mechanism. It was concluded that any separation based on this mechanism is likely to suffer from poor inter run reproducibility and must therefore be discounted as a suitable method. Similarly, ion-suppression reverse phase was shown to be equally impracticable, requiring a mobile phase pH of less than 2 to obtain separation (this low pH renders a silica based stationary phase unstable). (author)

[en] The document chronicles, and draws summary conclusions from, the activities of the X4 R+D Support Group from the start of the project on January 1, 2000 to the time of the Technical Review Meeting in Mol: 27-29 June, 2005. The objectives to be accomplished were set out in a Baseline document. These were: to define the lower target flow configuration, within the geometric constraints imposed by the physical boundary conditions (geometrical confinement, lead- bismuth eutectic (LBE) inventory, pump capacities, target heat exchanger (THX) power, etc.); to identify, and evaluate, optimum target window design to minimise thermal loads and pressure drops, and to avoid hot-spots and flow instabilities; to demonstrate reliable cooling of the lower target enclosure (LTE); to demonstrate the structural integrity of the lower section of the Iiquid-metal container LMC) and its internal components, and that of the LTE; to provide best-estimate safety margins on target coolability and structural integrity under operational flow conditions; to investigate, quantify, and make recommendations regarding, abnormal target operation including possible accident scenarios). The time-scale set for MEGAPIE was always such that much of the design work needed to be carried out at the same time as the R+D support. Often, the target design was changing faster than the time required to perform the detailed computer simulations. As a consequence, many of the simulations reported or referenced in this document do not refer to the very latest target design, and in many respects the results and conclusions must be regarded as generic in nature. Nonetheless, very valuable work has been carried out by the various organisations, and better understanding of the expected temperature distributions and stress levels in the operating MEGAPIE target has been gained, and direct feed-back to the design team on various aspects of the design details has taken place as a consequence of this work. As the design approached maturity, the numerical models were updated and, based on the experience gained from the formative years of the X4 Group, rapid updates of results was made possible. In any cases, the basic principles had been established from the earlier, fundamental studies, and only required tuning to fit the later design details. Valuable data has come from the experiments performed in a representative MEGAPIE geometry and under near prototypic flow conditions. The data have fed directly into the project thinking, and have constituted a database for the validation of the thermal-hydraulic numerical tools used by the Group. The numerical and measured data collated in this document provides a comprehensive reference point for target behaviour in advance of it actually being connected to the coolant loops, tested, and ultimately exposed to the proton beam. The picture is not complete, and work remains ongoing, particularly in regard to fluctuations in the flow field. Nonetheless, a level of confidence in lower target coolability has been established, and is documented herein. (author)

[en] The MAXDOSE-EPA computer code is a methodology developed by the Office of Radiation Programs to estimate the potential radiation doses from accidental releases of radionuclides from a repository for high-level radioactive wastes sited in deep geologic media. The code is intended to be applicable to a generic repository. The model parameters describing the characteristics of the repository and its environment can be varied to show the effects of different characteristics. This report describes the equations used to obtain the radionuclide concentrations in the environment and to calculate radiation doses to man via inhalation of air and ingestion of water, milk, crops, beef, and fish. A listing of the code, an input guide, and a sample problem are included. The code is written in Fortran, requires less than 200 K storage, and runs in less than 30 seconds. The code calculates the maximum dose and makes many conservative assumptions that shorten the run time to under 30 seconds

[en] In support of the effort to maximize safety in nuclear power plants, Amdata, Inc., (under EPRI Contract RP 2165-08) conducted a study to determine the feasibility of utilizing the Amdata IntraSpect/98 (I/98) Ultrasonic Imaging System to inspect reactor pressure vessels. The I/98 was used to perform a full volumetric examination on a section of a low-alloy steel pressure vessel supplied by Westinghouse Electric Corporation. This specimen is reported to be typical of pressure vessels used in commercial pressurized water reactor plants. The test specimen measures 55 inches in diameter by 10.5 inches thick, weighs 7000 pounds, and has a stainless-steel clad weld along the full diameter. The volume inspected includes 36 inches along the length of the weld, 10 inches on each side of the weld centerline, and the entire 10.5 inch thickness. For the inspection, three ultrasonic transducers were mounted on a wheeled sled and positioned at three different angles (60 and 45 degrees shear wave, and 0 degree longitudinal wave). They were immersed in water to simulate the conditions of an actual inspection of a reactor pressure vessel. The test results show that the I/98 successfully inspected the Westinghouse specimen and is capable of successfully inspecting similar reactor pressure vessels. 31 figs., 2 tabs

[en] The year 2001 was marked by the extensive audit of energy research at PSI. The audit took place on 21/22 June, and nuclear energy research was evaluated by five international experts. It was possible to present the quality and relevance of our research in a convincing way. This, together with optimal use of the available resources in our department Nuclear Energy and Safety (NES), prompted the highly welcome result that the auditors attested a high degree of scientific quality to the NES projects in general, with some of them judged to be of world-class standard. They recommended all audited projects be maintained, adequate resources to be allocated accordingly and, if necessary, an increase of public funding in nuclear energy research to be granted to achieve this. Finally, it was recommended that energy research should be explicitly mentioned in the statement of the ultimate mission of PSI. At the level of 'daily work', efforts in several directions related to the future of the Hotlab were one of the main focuses during the past year. On the one hand, the safety-related backfitting of the facility (particularly in regard to fire protection) has been continued, and was coupled with intensive planning studies, and with a thorough radiological cleaning of the labs; this invariably led to some impediment to the current research activities. Despite external burdens, which have led to some delays and additional costs, three of the four refurbishment phases have been completed, and the corresponding laboratories were brought back into operation after inspection and approval by the regulatory authority HSK. Given the size and complexity of the project, progress must be considered very satisfactory. A list of scientific publications in 2000 is also provided

[en] Highlights of the main activities during the year covered by this report are given below in the framework of the corresponding projects. They include tasks that were completed during the year, as well as certain projects still in their early stages or start-up phase. While NES is encouraging a networking of its activities, both within the Department and throughout PSI (e.g. through its involvement in the MicroXAS Beamline; the MEGAPIE project; and the collaboration with the General Energy Department, ENE, in the context of the GaBE project), most of the activities are the prime responsibilities of the distinct organisational units (Laboratories) within NES. This basis forms a well-defined, scientific focus for the projects, each of which requires particular expertise and specialised equipment or facilities. (author)

[en] The Nuclear Energy Research Department consists of three Laboratories: Reactor Physics and Systems Engineering (LRS), Thermal Hydraulics (LTH), and Materials and Nuclear Processes (LWV). There are additionally two Research Programmes: 'Waste Disposal' (PES) and LWR-Safety (PLS). The Department's activities focus on three main areas: safety and safety-related operational problems of the Swiss nuclear power plants (NPPs), contributions to the issues involved in radioactive waste disposal, future reactors. In addition, scientific-technical services are provided in the nuclear and non-nuclear sectors and for the operation of the relevant site facilities. (author) figs., tabs., refs

[en] The National Coalition to Stop Food Irradiation which is actively campaigning against food irradiation in Australia, outlines both the promises and the potential problems occurring when exposing food to radiation. It is highly critical of the way the technology is being promoted and aims to provide factual information supporting public debate on the issue. A list of contacts and resource centres thorughout Australia is included. 35 refs., 3 figs