[en] The aim of this is to derive a reliable neutron spectrum information to be used in further shielding calculation. Consequently, it was intended to improve the quality of these information by emphasizing correct evaluation of the related uncertainty data. In order to meet these objectives, existing methods and procedures for neutron spectrum calculation and measurement were improved. (author)

No abstract available

No abstract available

[en] The program ANS which is the graphical user friendly program to process evaluated neutron data files for interpretation of transmission experiments. The ANS program was written in the Turbo Pascal v. 5 language and may work on the IBM AT with Math CoProcessor. 3 refs.; 1 fig

[en] The calculated sensitivity coefficients show that in a hybrid reactor the greatest influence on the principal functionals is exerted by the secondary neutron spectra of the reactions ²³⁸U(n, 2n), ^23BU(n, n/prime/) cont, and Fe(n, n/prime/) cont, for which the contribution to the fission rate in ²³⁸U and, therefore, in neutron multiplication per source neutron, may be considerable. The indeterminacy of the functionals, owing to the 15-20% inaccuracy of the spectra, is estimated for the hybrid reactor model studied to be 3-4.5% for the fission rate and 2-2.5% for the tritium yield

[en] Results from the HP irradiation test have been shown to reduce uncertainties associated with calculation of axial and radial flux and reaction rate distributions, flux perturbations due to core heterogeneities, neutron flux and reaction rates outside the fuel region, activation of structural components and sodium, and fuel burnup. Improved knowledge of reaction rates (hence burnup, power and flux distributions) is expected to result in better prediction of the performance of experiments irradiated in FFTF

No abstract available

No abstract available

[en] Two levels of neutron spectrometry are in regular use at nuclear power plants: some techniques used in the laboratory produce detailed spectra but require specialist operators, while simple instruments used by non-specialists to measure the neutron dose-rate to operators provide little spectral information. The standard portable instruments are therefore of no use when anomalous readings are obtained which require further investigation. AEA Technology at Winfrith has developed a Transportable Neutron Spectrometer (TNS) which is designed to produce reasonable spectra in routine use by staff with no specialist skill in spectroscopy, and high-quality spectra in the hands of skilled staff. The TNS provides a level of information intermediate between those currently available, and is also designed to solve the problem of imperfect dose response which is common in portable dosimeters. The TNS system consists of a power supply, a probe and a signal processing and data acquisition unit. (author)

[en] It has long been recognized that different neutron spectrum unfolding codes will produce significantly different results when unfolding the same measured data. In reviewing the results of such analyses it has been difficult to determine which result if any is the best representation of what was measured by the spectrometer detector. A proposal to develop a benchmarking procedure for spectrum unfolding codes is presented. The objective of the procedure will be to begin to develop a methodology and a set of data with a well established and documented result that could be used to benchmark and standardize the various unfolding methods and codes. It is further recognized that development of such a benchmark must involve a consensus of the technical community interested in neutron spectrum unfolding