First wheat certified reference material for organically bound tritium measurement in the environment.

Measuring the radioactivity of organically bound tritium in environmental samples is difficult. For the past twenty years, many laboratories have been working on the development of reliable tritium measurement methods. In this context, several interlaboratory comparisons have been organised to develop these methods and enable laboratories to compare themselves.

Treatment of radioactive liquid effluents by reverse osmosis membranes: From lab-scale to pilot-scale.

The recent use of the reverse osmosis (RO) process at the damaged Fukushima-Daiichi nuclear power plant generated a growing interest in the application of this process for decontamination purposes. This study focused on the development of a robust RO process for decontamination of two kinds of liquid effluents: a contaminated groundwater after a nuclear disaster and a contaminated seawater during a nuclear accident. The SW30 HR membrane was selected among other in this study due to higher retentions (96% for Cs and 98% for Sr) in a true groundwater.

Investigation of gamma radiation effect on the anion exchange resin Amberlite IRA-400 in hydroxide form by Fourier transformed infrared and 13C nuclear magnetic resonance spectroscopies.

Radiation-induced decomposition of the anion exchange resin Amberlite IRA-400 in hydroxide form by gamma radiolysis has been studied under different irradiation doses and irradiation atmospheres. In this work, we focused on the degradation of the solid part of the resin by Fourier transformed infrared (FTIR) and (13)C nuclear magnetic resonance (NMR) spectroscopies associated with chemometric treatments. FTIR and (13)C NMR techniques showed that only -CH(2)N(+)(CH(3))(3) groups were detached from the resin whereas the polystyrene divinylbenzene backbone remains intact.

Structural characterisation of degradation products formed upon di-n-butyl phthalate radiolysis by high-performance liquid chromatography electrospray tandem mass spectrometry.

Structural characterisation of 15 degradation products, formed upon di-n-butyl phthalate (DBP) radiolysis, has been achieved using a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) coupling. The dissociation behaviour of protonated DBP was first established to be further used to characterise structural deviation in the degradation products. Based on accurate mass measurements, compounds shown by HPLC-MS analysis were all found to be DBP oxidation products, amongst which various sets of isomers could be distinguished.

Radon (222Rn) level variations on a regional scale: influence of the basement trace element (U, Th) geochemistry on radon exhalation rates.

The approach proposed in this study provides insight into the influence of the basement geochemistry on the spatial distribution of radon (222Rn) levels both at the soil/atmosphere interface and in the atmosphere. We combine different types of in situ radon measurements and a geochemical classification of the lithologies, based on 1/50,000 geological maps, and on their trace element (U, Th) contents. The advantages of this approach are validated by a survey of a stable basement area of Hercynian age, located in South Brittany (western France) and characterized by metamorphic rocks and granitoids displaying a wide range of uranium contents.

Study of 222Rn permeation through polymer membranes II: calibration curves of a new device equipped with a polyethylene membrane, for continuous measurement of 222Rn in water-saturated soils.

The permeation of 222Rn through plastic membranes has been studied in order to improve a solid-state measuring device BARASOL and to use it in water-saturated soils. Preliminary results show that polyethylene is the most efficient membrane (sufficiently permeable to radon and impermeable to water). In the present study, we have adapted polyethylene membranes to the BARASOL probe and tested them, in this configuration, with a special experimental set-up.

Study of 222Rn permeation through polymer membranes: application to continuous measurement of 222Rn in water.

Membranes that exclude water but are permeable to radon can extend the range of environments where many radon detection systems could operate. We have studied the permeation of 222Rn through polypropylene membranes separating air and water phases. The permeation coefficient and the activation energy were calculated for various conditions.