A Device for Nondestructive Experimental Determination of the Power Distribution in a Nuclear Fuel Assembly

• Published in: Nuclear science and engineering Vol. 152; no. 1; pp. 76 - 86
• Main Authors: Jansson, P., Svärd, S. Jacobsson, Håkansson, A., Bäcklin, A.
• Format: Journal Article
• Language: English
• Published: La Grange Park, IL Taylor & Francis 01.01.2006; American Nuclear Society
• Subjects: Applied Nuclear Physics; Applied sciences; Energy; Exact sciences and technology; Fuels; Fysik med inriktning mot tillämpad kärnfysik; nuclear fuel; Nuclear fuels; Physics with specialization in Applied Nuclear Physics; Preparation and processing of nuclear fuels; Tillämpad kärnfysik; tomography; Computation code; Nuclear fuel; Nuclear reactor; Boiling water reactor; Gamma radiation; Fission product; Fuel assembly; Power distribution; Tomography; Numerical simulation; Fuel rod; Barium 140; Non destructive test; Reactor core; Pressurized water reactor
• ISSN: 0029-5639; 1943-748X; 1943-748X
• DOI: 10.13182/NSE06-A2565

There is a general interest in experimentally determining the power distribution in nuclear fuel. The prevalent method is to measure the distribution of the fission product 140 Ba, which represents the power distribution over the last few weeks. In order to obtain the rod-by-rod power distribution, the fuel assemblies have to be dismantled. In this paper, a device for experimental nondestructive determination of the thermal rod-by-rod power distribution in boiling water reactor and pressurized water reactor fuel assemblies is described. It is based on measurements of the 1.6-MeV gamma radiation from the decay of 140 Ba/La and utilizes a tomographic method to reconstruct the rod-by-rod source distribution. No dismantling of the fuel assembly is required. The device is designed to measure an axial node in 20 min with a precision of >2% (1σ). It is primarily planned to be used for validation of production codes for core simulation but may also be used for safeguards purposes.