Status of Pelletised Moderator Neutronics Research for the Spallation Neutron Source Long Wavelength Target Station

Article type: Research Article

Authors: Iverson, E.B. | Forsythe, D.C. | Heuser, B.J. | Carpenter, J.M.

Affiliations: Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA | Nuclear Engineering Department, University of Illinois, Urbana, IL 61801, USA | Intense Pulsed Neutron Source, Argonne National Laboratory, Argonne, IL 60439, USA

Note: [] Corresponding author. E-mail: iversoneb@sns.gov

Abstract: We explore methods for making detailed calculations on the neutronic performance of a pelletised moderator, wherein a significant fraction of the moderating medium is heterogeneously distributed. This pellet approach appears to be necessary to provide cooling capabilities to a solid moderator material under heavy heat loads, and furthermore appears to offer the only realistic mechanism for permitting solid moderators in situations where the moderator material stores energy from radiation damage at a significant rate. Current use of solid moderators (e.g. methane at the Intense Pulsed Neutron Source facility) is significantly limited by the need to avoid catastrophic release of this stored energy.

Keywords: Spallation, Neutron moderation, Pulsed moderator design, Pellet moderator, Burping

DOI: 10.1080/1023816031000100969

Journal: Journal of Neutron Research, vol. 11, no. 1, 2, pp. 107-112, 2003