Determination of the Fuel-Assembly Burnup in a Research Reactor by Repeated Short-Time Irradiation Followed by g Spectrometric Measurements

• Published in: Atomic energy (New York, N.Y.) N.Y.), 2004-08, Vol.97 (2), p.571-576
• Main Authors: Bushuev, A V, Kozhin, A F, Li, G, Zubarev, V N, Portnov, A A, Alferov, V P, Shchurovskaya, M V
• Format: Article
• Language: English
• ISSN: 1063-4258; 1573-8205
• DOI: 10.1023/B:ATEN.0000047684.15193.2d

Experiments performed to determine the absolute fuel burnup in spent fuel assemblies in the IRT research reactor at the Moscow Engineering Physics Institute are described. The method is based on measuring the residual amount of super(235)U in the spent fuel asemblies with respect to the activity of the fission product super(140)La accumulated in fresh and spent fuel assemblies after they were irradiated for a short time in the reactor core. A fresh fuel assembly with known uranium mass was used as a standard. The neutron flux was monitored using Al + Cu and Al + Co wires placed at the center of the fuel assembly. Small corrections for the difference in the spectrum amd the flux density of the neutrons in fuel assemblies with different uranium content were obtained from the calculations. The burnup of the three fuel assemblies studied was determined to within less than 2%.