DETERMINATION OF THE 234U ISOTOPE CONTENT IN URANIUM-BEARING MATERIALS USING HIGH-RESOLUTION GAMMA SPECTROMETRY

The paper presents an overview of the research into the available non-destructive methods of determining the 234U isotope content in uranium-bearing materials. An alternative approach to a problem of detector calibration by the characteristic “intrinsic” efficiency is proposed. Certified reference uranium-bearing materials CRM 969 and CRM 146 (a range of 235U enrichments studied was 0.3…93%) were used as test samples, measurements were carried out with a wide-range energy detector based on the high-purity BeGe 3830 germanium (Canberra, USA) with 38 cm2 area and 3 cm thickness. An approach used for the “intrinsic” efficiency calibration for the 234U analysis permits to decrease the measurement error to 7.5% in the whole range of 235U enrichment (from 0.3 to 93%) and 234U concentrations (20 to 9800 µg/g). The proposed method does not demand standard samples for equipment calibration and does not depend on the physical (chemical) form of the investigated material and measurement geometry.

Internal dose rate in quartz grains: Implications for luminescence dating

<div> <p>This study assesses how internal dose rate in quartz grains impacts luminescence dating.  In 2018, the Gliwice Luminescence Laboratory implemented innovative μDose system which combines advantages of alpha and beta counting measurement techniques with additional radioactive identification capabilities. The device allows measurements of small samples and results verification with an independent high-resolution gamma spectrometry method. </p> </div><div> <p>All measurements of internal dose rate were made on  pure quartz grains after standard chemical pretreatment. Grains with diameters between 125 and 200 μm were selected for measurements. This material was dried and grounded to approx. 20 μm using a planetary ball mill prior to measurements on the μDose systems.  </p> </div><div> <p>Internal dose rate reported here is particularly important because of low (about 0.8-0.9 Gy/ka) or very low (0.4-0.6 Gy/ka) external dose rates. Internal dose rate in quartz grains in our measurements is a significant fraction of the total dose rate, often exceeding 10%. Ignoring this correction would make luminescence ages in our study artificially older.</p> <p><span xml:lang="EN-US" data-contrast="auto"><span>Presented results were obtained with support of Polish National Science Centre, contract number 2018/30/E/ST10/00616</span></span><span> </span></p> </div>

A Study of Greek Building Materials as Indoor Radon Sources

A survey of radon emanation in building materials commonly used in Attica has initiated at our laboratory as part of a broader EU program. The objective is to obtain a characterisation of the Greek building materials as indoor radon sources and identify the cases where some specific countermeasures should be applied. Up to now, bricks commonly used in Attica have been studied for both radium content and radon emanation. Gamma-ray spectroscopy techniques, as well as radon exhalation measurements, have been employed. For determination of radon exhalation rate, besides the trivial method which consist of a single measurement of radon concentration in a closed vessel containing the sample, a short-time continuous accumulation/counting method has been established. The results of exhalation measurements have been used together with high-resolution gamma-spectrometry in order to determine radon emanation coefficients.