Non-Destructive Experimental Determination of the Power Distribution in Nuclear Fuel Assemblies

• Modern production codes for core simulation perform calculations of the thermal power distribution on the individual fuel rod level. The prevalent technique to experimentally validate such calculations involves dismantling of the fuel assemblies, whereby gamma-ray measurements on individual fuel rods are performed to determine the content of the fission product 140Ba. Here, an alternative, non-destructive technique is presented, which is based on tomography. The gamma-ray flux distribution in an axial node is recorded, whereby the relative rod-by-rod content of 140Ba is reconstructed. The method does not require the fuel to be dismantled. Neither does the fuel channel present in BWR assemblies have to be removed. The applicability of the technique has been demonstrated in measurements at the Swedish BWR Forsmark 2 using a special-purpose device. The measurements were performed on irradiated fuel with a cooling time of 4 5 weeks. Data from the production code POLCA 7 has been compared to the measured rod-by-rod contents of 140Ba and an agreement of 3.0% (1 σ) has been demonstrated.

Ämnesord

NATURVETENSKAP  -- Fysik -- Subatomär fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Subatomic Physics (hsv//eng)

Nyckelord

Nuclear physics

Kärnfysik

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