EPJ Web of Conferences
Volume 106, 2016ISRD 15 – International Symposium on Reactor Dosimetry
|Number of page(s)||8|
|Section||Dosimetry in Research and Test Reactors and in Accelerators|
|Published online||03 February 2016|
Characterization of Novel Calorimeters in the Annular Core Research Reactor *
1 Sandia National Laboratories, Applied Nuclear Technologies Department, P.O. Box 5800, Albuquerque, New Mexico 87185, USA
2 Sandia National Laboratories, Advanced Nuclear Concepts Department, P.O. Box 5800, Albuquerque, New Mexico 87185, USA
Published online: 3 February 2016
A series of pulsed irradiation experiments have been performed in the central cavity of Sandia National Laboratories' Annular Core Research Reactor (ACRR) to characterize the responses of a set of elemental calorimeter materials including Si, Zr, Sn, Ta, W, and Bi. Of particular interest was the perturbing effect of the calorimeter itself on the ambient radiation field – a potential concern in dosimetry applications. By placing the calorimeter package into a neutron-thermalizing lead/polyethylene (LP) bucket and irradiating both with and without a cadmium wrapper, it was demonstrated that prompt capture gammas generated inside the calorimeters can be a significant contributor to the measured dose in the active disc region. An MCNP model of the experimental setup was shown to replicate measured dose responses to within 10%. The internal (n,γ) contribution was found to constitute as much as 50% of the response inside the LP bucket and up to 20% inside the nominal (unmodified) cavity environment, with Ta and W exhibiting the largest enhancement due to their sizable (n,γ) cross sections. Capture reactions in non-disc components of the calorimeter were estimated to be responsible for up to a few percent of the measured response.
© Owned by the authors, published by EDP Sciences, 2016
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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