Development of cesium standard from irradiated U₃SI₂/AL of 2.96 gU/cm³ fuel solution by CsClO₄ precipitation method

A considerable ammount of irradiated nuclear fuel solutions exist in the hotcell area of Radiometallurgy Instalation (IRM). These solutions were generated from sampling activities for bumup test. The solutions can not be disposed due to the present of ¹³⁷Cs isotope and other heavy elements that have a long half time, but the solutions can be used as a secondary source of ¹³⁷Cs standard for analysis purposes. Post-irradiation fuel analysis is always conducted by a valid method and with a calibrated spectrometer-γ. The standard used in the calibration of spectrometer-γ energy or activity is ¹³⁷Cs isotope. There have been some restriction in the use of spectrometer-γ because spectrometer-γ calibration can not be performed routinely due to the unavailability of standard sources. The availability of ¹³⁷Cs isotope for R&D is still dependent on abroad suppliers. Therefore, in this research, PTBBN and PTKMR aim to develop a secondary standard source of ¹³⁷Cs isotope with 10330 ± 411 Bq activity. The standard source was obtained from a solution of ¹³⁷Cs separated from U₃Si₂/Al irradiated fuel. The separation was done by precipitation method with CsNO₃ and HClO₄ as the carrier. The result of the separation is ¹³⁷CsClO₄ precipitate, dried and weighed for obtaining greater activity and measured with a spectrometer-γ. The dried precipitate ¹³⁷CsClO₄ was subsequently packed as closed standard source (shield source). This standard sourced was certified by PTKMR as secondary standard isotope of ¹³⁷Cs and is ready to be used for energy calibration of spectrometer-γ. (author)