[en] The apparent diffusion coefficient of ³⁶Cl is used to assess pore geometric changes in allophane soil resulting from drying. The diffusion method is based on the boundary condition of a planar source diffusing into an infinite medium. The extent of structural changes accompanying drying was indicated by changes in slope of a plot between geometric and interaction factors versus volumetric moisture content. Structural change was least for freeze drying to be followed by a larger but equal change for air and oven drying. (M.A.C.)

No abstract available

No abstract available

[en] The monitoring of long-lived radionuclides is of great importance in the context of the surveillance of nuclear facilities, during their operation as well as during their decommissioning. This is especially true for radionuclides of rather volatile elements, such as chlorine and iodine, the main interest being in ³⁶Cl and ¹²⁹I. Liquid Scintillation Counting (LSC) is a widely used measurement technique especially for the determination of ³⁶Cl that requires a thorough and selective sample preparation in order to give accurate results. Sample preparation methods frequently employed such as volatilization and/or repeated precipitation steps can be rather elaborate and time consuming. Therefore, an attempt has been made to develop an 'easy to use' extraction chromatographic resin that allows extraction, and subsequent separation, of chloride and iodide from pretreated environmental and decommissioning samples for their determination via LSC. First results of the characterization of the resin including D_w values of Cl^-, I^- and potential interferents, and of the method development are presented as well as the result of the analysis of a simulated real sample. (author)

[en] Prior to 2005, the EDF initial version for the radiological inventory of graphite was based on the maximum values of the measures, namely a very pessimistic way. In 2008, a scientific method was developed by EDF to evaluate the inventory by reverse activation calculation, in order to limit the overestimation. The radiological inventory computation principles can be compared to those of all engineering studies. First, the calculation is simplified by taking margins, and if the results are not satisfactory enough, some simplifications are suppressed to reduce these margins even if computation becomes more complicated. On EDF piles, the gain obtained in 2008 represented a factor 50 relative to the initial version of Cl-36, even with a very penalizing multiplicative factor for uncertainty. Today, the accurate calculation of the uncertainty no longer justifies such a factor. A gain of about 150 now occurs compared to the initial version of Cl-36. It is more than 2 orders of magnitude, which is already enough to assess again the necessary type of disposal because Cl-36 is one of the key radionuclides. After global presentation of graphite waste management in France, the paper focuses on the inventory scientific process of EDF nuclear graphite, the purity of graphite and its consequences, its particular sampling, the lessons learned, the initial method description, the link with the demonstration of the completely random point process of chlorine in nuclear graphite and the last suggested precise uncertainty computation of inventory of Cl-36. The method confirmation for concentration assessment, the history of the EDF method development and its benefits are also emphasized. (authors)

[en] Abstract only

No abstract available

[en] Published in summary form only

[en] The results are reported on the measurement of the thermal cross section of the (n,p) reaction for the ³⁶Cl radioactive nucleus. For spectrometry analysis and identification of low-energy charged particles the ionization chamber with two grids was used. For the first time the thermal cross section has been found to be equal σ(n_th,p)=0.4 ±0.1 b. It makes possible to determine the ³⁶Cl/³⁵Cl ratio on the 10^-8 level, which could be interesting for the isotope chronology

[en] This paper reports on the results of measurements of the (n,p) and (n,α) reactions on ²⁶Al and ³⁶Cl, in the neutron energy region up to 140 keV and 350 keV, respectively. The experiments were carried out at the GELINA neutron facility of the IRMM (Geel, Belgium). For both reactions several resonances could be identified which were never observed before. Using the obtained cross section data, reaction rates were calculated and compared with other experimental and theoretical values