DISSOLUTION AND BURNUP DETERMINATION OF IRRADIATED U-Zr ALLOY NUCLEAR FUEL BY CHEMICAL METHODS

• Published in: Nuclear engineering and technology Vol. 38; no. 3; pp. 301 - 310
• Main Authors: Kim, Jung-Suk, Jeon, Young-Shin, Park, Soon-Dal, Song, Byung-Chul, Han, Sun-Ho, Kim, Jong-Goo
• Format: Journal Article
• Language: Korean
• Published: 한국원자력학회 01.04.2006
• Subjects: 원자력공학; Nd Isotope Monitor; Burnup Measurement; IDMS; U-Zr Alloy Fuel
• ISSN: 1738-5733; 2234-358X

Destructive methods were used for the burnup determination of U-Zr alloy nuclear fuel irradiated in the High-flux Advanced Neutron Application Reactor (HANARO) at KAERI. The dissolution rate of unirradiated U-Zr alloy fuel in $HNO_3$/HF mixtures was investigated for the experimental conditions of a different temperature, and initial concentrations of HF and $HNO_3$. The irradiated U-Zr alloy fuel specimen was dissolved in a mixed acid condition of 3 M HNO3 and 1 M HF at $90^{\circ}C$ for 8 hours under reflux. The total burnup was determined from measurement of the Nd isotope burnup monitors. The method includes U, Pu, $^{148}Nd,\;^P{145}Nd+^{146}Nd,\;^{144}Nd+^{143}Nd$ and total Nd isotopes determination by the isotope dilution mass spectrometric method (IDMS) using triple spikes $(^{233}U,\;^{242}Pu\;and\;^{150}Nd)$. The effective fission yield was calculated from the weighted fission yields averaged over the irradiation period. The results are compared with that obtained by the destructive -spectrometric measurement of the $^{137}Cs$ monitor.