H-3 Measurement in Radioactive Wastes: Efficiency of the Pyrolysis Method to Extract Tritium from Aqueous Effluent, Oil, and Concrete

Abstract

Tritium measurement in nuclear waste is a key to determine the type of repository. This paper describes the methodology used to validate tritium measurement in various matrices using pyrolysis method with a new instrument available in the market. The efficiency obtained for tritium recovery in aqueous matrix, oil and concrete are respectively higher than 95%, 93% and 85%.

Intercomparison exercise on difficult to measure radionuclides in activated steel: statistical analysis of radioanalytical results and activation calculations

“…The iterations of the robust mean and standard deviations were continued until there was no change in the 3rd significant figure of the robust means and standard deviations [2]. In this paper, the robust means and standard deviations of 55 Fe, 63 Ni, 14 C and 60 Co calculated from participant's results are referred to as measured assigned values.…”

“…The radiochemical analyses of 55 Fe, 63 Ni and 14 C were based on either internal or published procedures. A general summary of the procedures is presented by Leskinen et al [3] and detailed procedures in the references [6][7][8][9][10][11][12][13][14]. Due to anonymity, procedures were not linked with specific analytical results.…”

“…The analysis of 14 C was carried out either using an acid digestion with oxidation of carbon to CO 2 or by using a dedicated equipment for volatile radionuclides, namely Oxidizer (Perkin Elmer), Pyroxidiser (Eraly) and Pyrolyser (RAD-DEC). All the dedicated equipment are furnaces with oxygen as carrier gas in first equipment and air supplemented with oxygen in the last two equipment.…”

“…All the dedicated equipment are furnaces with oxygen as carrier gas in first equipment and air supplemented with oxygen in the last two equipment. In all cases, the released 14 C is trapped in a basic solution (generally Carbosorb or NaOH) which is then analysed by LSC. 14 C yields were determined using liquid sources.…”

“…Analysis of difficult to measure (DTM) radionuclides, such as 3 H, 14 C, 36 Cl, 41 Ca, 55 Fe, 63 Ni etc., in radioactive waste is a challenging task not only due to the lengthy radiochemical procedures with several sources of uncertainties but also due to the possible heterogeneity of the studied waste material. In addition, uncertainties can also originate from the sampling technique.…”