Measurement of low-activity uranium contamination by gamma-ray spectrometry for nuclear decommissioning

A Reliable Absolute and Relative Bayesian Method for Nuclear Decommissioning: Low-Level Radioactivity Detection With Gamma-Ray Spectrometry

“…In this perspective, the availability of a physical model of uranium surface contaminations, as well as of high-resolution spectra from an HPGe detector, encouraged us to develop novel Bayesian hypothesis tests to compete with the frequentist ones presented in [2]. We recall that the main purpose of this study is to ensure, with an acceptable measurement integration time, an operational trade-off between TDR and FAR in the context of nuclear decommissioning.…”

“…Gamma-ray spectrometry based on HPGe detector (HPGe) is the best available solution to detect low uranium activity because of its high energy resolution [7]. This figure of merit of HPGe, indeed, allows to define narrower regions of interest (ROI) around selected gamma-ray peaks in order to increase signal-to-noise ratio (SNR) for low activity measurement [2], [8,9]. Nevertheless, high detection limits under low SNR (typically in the order of 1 over 1s), are still observed with traditional algorithmic approaches, which forms a major limitation in the application field of nuclear decommissioning.…”

“…Hanan Arahmane, Jonathan Dumazert, Eric Barat, Thomas Dautremer, Nicolas Dufour, Frédérick Carrel, Maugan Michel, Frédéric Lainé A of low-activity uranium contamination on nuclear facilities' concrete surfaces [2]. These tests allowed to perform a computation of the measurement statistical power, and thus to define the confidence interval of the true detection rate (TDR) and false alarm rate (FAR).…”

“…However, the absolute CNB test has the weakness of being impacted by any significant variation (  5 % ) associated with the background signal intensity. Hence, it was necessary to introduce an alternative version of the test, taking into account the dispersion of the counting intensity [2]. To this aim, a relative and unilateral test, based on the cumulative function of a Beta Binomial law (CBB), was developed.…”

Optimization of Plastic Scintillator for Detection of Gamma-Rays: Simulation and Experimental Study

“…In terms of radiation management, radioactive waste generated from nuclear facilities requires thorough radiological measurement and evaluation because there is a possibility of radiation exposure of workers and the release of radioactive materials into the environment during decommissioning. The scintillation detector widely used for in situ measurements is one of the most representative methods of indirect ionization and consists of a scintillator and an optical sensor [18][19][20][21][22]. The scintillator interacts with radiation such as gamma-rays and then emits light in the UV or visible region, and the photosensor converts the light into an electrical signal.…”