[en] This evaluation was done originally in September 2005 and then revised in April 2009 with a literature cut-off by the same date. Decay Scheme: The decay scheme is based on 2006Ba41

[en] The rate at which the first nuclear state becomes populated is calculated as a function of temperature up to 30 keV for compressions from 0.3 times normal density to 100 times normal density for ²³⁷U. Detailed results are also presented for ²³⁸U. The deexcitation rates are shown to change by several orders of magnitude and the excitation rates are shown to be in the order of several percent per nonosecond at high temperatures and compressions

[en] The photo-neutron cross section (σ(γ, n) have been measured for ²³⁸U using Bremsstrahlung peak energy of 8 MeV. Activation followed by off line γ-ray spectrometric technique was employed. The Bremsstrahlung flux was measured using the fission products of ²³⁸U. The ²³⁸U(γ, n)²³⁷U cross section is also calculated theoretically using TALYS 1.2. The experimentally obtained reaction cross sections were compared with the flux weighted average values from the available literature data as well as the value from TALYS based on mono-energetic photon. A good overall agreement was observed. (author)

No abstract available

[en] Results of the multidimensional analysis of fragments produced in ²³⁶U fission induced by 1 MeV neutrons are presented. Cold fragmentation sspectra have been analyzed. The global changes are shown in fragments angular distributions with moving scission point from the saddle configuration

No abstract available

[en] The aim of this work was to calculate the values of the ²³⁴U/²³⁸U activity ratio in natural environment (water, sediments, Baltic organisms and marine birds from various regions of the southern Baltic Sea; river waters (the Vistula and the Oder River); plants and soils collected near phosphogypsum waste heap in Wislinka (Northern Poland) and deer-like animals from Northern Poland. On the basis of the studies it was found that the most important processes of uranium geochemical migration in the southern Baltic Sea ecosystem are the sedimentation of suspended material and the vertical diffusion from the sediments into the bottom water. Considerable values of the ²³⁴U/²³⁸U are characterized for the Vistula and Oder Rivers and its tributaries. The values of the ²³⁴U/²³⁸U activity ratio in different tissues and organs of the Baltic organisms, sea birds and wild deer are varied. Such a large variation value of obtained activity ratios indicates different behavior of uranium isotopes in the tissues and organisms of sea birds and wild animals. This value shows that uranium isotopes can be disposed at a slower or faster rate. The values of the ²³⁴U/²³⁸U activity ratio in the analyzed plants, soils and mosses collected in the vicinity of phosphogypsum dumps in Wislinka are close to one and indicate the phosphogypsum origin of the analyzed nuclides. Uranium isotopes ²³⁴U and ²³⁸U are not present in radioactive equilibrium in the aquatic environment, which indicates that their activities are not equal. The inverse relationship is observed in the terrestrial environment, where the value of the of the ²³⁴U/²³⁸U activity ratio really oscillates around unity. (author)

[en] This study was undertaken to investigate the long-term performance of elemental iron as reactive material for the removal of uranium in passive groundwater remediation systems. By using ²³⁷U as a radioindicator it was possible to track the movement of the contamination front through a test column without taking samples or dismantling the apparatus. The stoichiometric ratio between uranium and iron was found to be 1:(1390±62). The reaction between iron and uranium is of pseudo first-order kinetics and the rate constant was measured to be (1.1±0.09)x10^-3 s^-1. These data enable the calculation of ideal lifetime for permeable reactive barriers (PRB) using iron for uranium removal neglecting hydrological factors that may impair the function of PRBs

[en] The activity of "2"4"1Pu in the biological samples (tissue, blood etc) is an important input for the assessment of internal dose received by the workers. The radiochemical separation of Pu isotopes and "2"4"1Am in a sample followed by á/â counting is a widely used method for their determination. However, this method is time consuming and needs longer time in sample preparation and radiochemical analysis. In this work, we have standardized a methodology for the determination of "2"4"1Pu in the biological sample by measuring its ã/x-rays with low energy HPGe detector. Decay scheme of "2"4"1Pu is shown. "2"3"7U achieves secular equilibrium with its parent "2"4"1Pu in 47 days, therefore ã-ray photons emitted by "2"3"7U are used for the estimation of "2"4"1Pu activity. But both the daughters of "2"4"1Pu viz "2"3"7U and "2"4"1Am decay to same isotope "2"3"7Np and populate the same excited states of "2"3"7Np, hence most of the ã-ray energies of "2"3"7U and "2"4"1Am are same. For the estimation of "2"4"1Am and "2"4"1Pu activity present in the sample 59.5 keV and 208 keV photons emitted by these radionuclides have been used in this study

[en] Operation of a plutonium separation facility requires rapid and accurate determination of the ²⁴¹Am content of the process streams and the final product solution. Most literature methods for the direct gamma spectrometric determination of ²⁴¹Am in plutonium either require access to a computer or are not applicable to freshly processed solutions due to a contribution from ²³⁷U to the 59.54 keV gamma peak. A rapid, accurate method for analysis of ²⁴¹Am in plutonium solutions using a Ge(Li) spectrometer is described. Correction for the ²³⁷U contribution to the 59.54 keV peak is made by monitoring the 208.0 keV peak, which is specific for ²³⁷U. The method requires no separation and is applicable to materials of any age. (U.S.)