Abstracts and Available Papers Presented at the 2002 International RERTR Meeting
TEST RESULTS AND MODEL EVALUATION FOR
THE HEU TO LEU CONVERSION OF THE UMASS-LOWELL
John R. White, Professor, Chemical and Nuclear Engineering Department
Leo Bobek, Reactor Supervisor, UMass-Lowell Radiation Laboratory
of Massachusetts Lowell
Lowell, MA 01854
The 1 MW UMass-Lowell Research
Reactor (UMLRR) switched from high-enriched uranium (HEU) fuel to low-enriched
uranium (LEU) fuel in August 2000.
Several months prior to conversion, a detailed physics study was
undertaken to fully characterize the new LEU core, with focus on providing
computational support for the actual startup and on estimating the radiation
environment in the various experimental facilities in the new LEU-fueled core.
During startup testing, a series of actual reactivity
evaluations and thermal flux magnitude and distribution measurements were
made. These startup tests not only
established operability of the new core, they also allowed direct evaluation of
the computational models and methods used to design and characterize the new LEU core.
This paper highlights this evaluation by summarizing the
overall startup test program and the computational methods in use at UMass-Lowell, and by providing a set of comparisons between
the measurement results and the computational estimates. Although some differences were observed, it
is apparent from the results presented that the overall computational
methodology was quite satisfactory --
since the as-built system operates essentially as designed.