Precise radiocarbon determination in radioactive waste by a laser-based spectroscopic technique

Year: 2022

Authors: Santi MGD., Insero G., Bartalini S., Cancio P., Carcione F., Galli I., Giusfredi G., Mazzotti D., Bulgheroni A., Ferri AIM., Alvarez-Sarandes R., de las Heras LA., Rondinella V., De Natale P.

Autors Affiliation: CNR, Ist Nazl Ott, I-80078 Pozzuoli, Italy; CNR, Ist Nazl Ott, I-50019 Sesto Fiorentino, Italy; Ist Nazl Ric Metrol, I-10135 Turin, Italy; European Lab Nonlinear Spect, I-50019 Sesto Fiorentino, Italy; PpqSense Srl, I-50013 Campi Bisenzio, Italy; Univ Firenze, Dipartimento Ingn Ind, I-50139 Florence, Italy; European Commiss, Joint Res Ctr JRC, D-76125 Karlsruhe, Germany; CNR, Ist Nazl Ott, I-50125 Florence, Italy.

Abstract: The precise and accurate determination of the radionuclide inventory in radioactive waste streams, including those generated during nuclear decommissioning, is a key aspect in establishing the best-suited nuclear waste management and disposal options. Radiocarbon (C-14) is playing a crucial role in this scenario because it is one of the so-called difficult to measure isotopes; currently, C-14 analysis requires complex systems, such as accelerator mass spectrometry (AMS) or liquid scintillation counting (LSC). AMS has an outstanding limit of detection, but only a few facilities are available worldwide; LSC, which can have similar performance, is more widespread, but sample preparation can be nontrivial. In this paper, we demonstrate that the laser-based saturated-absorption cavity ring-down (SCAR) spectroscopic technique has several distinct advantages and represents a mature and accurate alternative for C-14 content determination in nuclear waste. As a proof-of-principle experiment, we show consistent results of AMS and SCAR for samples of concrete and graphite originating from nuclear installations. In particular, we determined mole fractions of 1.312(9) (FC)-C-14 and 30.951(7) (FC)-C-14 corresponding to similar to 1.5 and 36.2 parts per trillion (ppt), respectively, for two different graphite samples originating from different regions of the Adiabatic Resonance Crossing activator prototype installed on one irradiation line of an MC40 Scanditronix cyclotron. Moreover, we measure a mole fraction of 0.593(8) (FC)-C-14 (similar to 0.7 ppt) from a concrete sample originating from an external wall of the Ispra-1 nuclear research reactor currently in the decommissioning phase.

Journal/Review: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

Volume: 119 (28)      Pages from: e2122122119-1  to: e2122122119-6

More Information: We thank Prof. Roberto Caciuffo for his contribution in importing the SCAR technology into the nuclear field. We also thank the team of the CologneAMS at the University of Cologne and in particular, Dr. Erik Strub for endless support in the interpretation of the AMS results and the Analytical Service of the Joint Research Centre (JRC) Karlsruhe for the total carbon determination. The realization of a SCAR setup in Karlsruhe was funded by the European Commission, Joint Research Centre under the Exploratory Research Programme.
KeyWords: nuclear waste; decommissioning; radiocarbon; nuclear safety; saturated-absorption cavity ring-down spectroscopy
DOI: 10.1073/pnas.2122122119

Citations: 7
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-17
References taken from IsiWeb of Knowledge: (subscribers only)
Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here