Program - Brookhaven National Laboratory

the Handbook. Since ND 2007, the contents of the International Handbook of Evaluated Reactor Physics
Benchmark Experiments has increased from 16 different experimental series that were performed at 12
different reactor facilities to 68 experimental series that were performed at 36 reactor facilities. Significant
additions of reactor physics measurement data have also been made to previously published evaluations.
The status of the ICSBEP and the IRPhEP will be discussed, selected benchmark configurations that have
been added to the ICSBEP and IRPhEP Handbooks since ND 2007 will be highlighted. A preview of the
new benchmark evaluations that will appear in the September 2013 edition of the ICSBEP Handbook will
also be provided. The future of both projects will be outlined.
CE 2 2:00 PM
Evaluation of Delayed Critical ORNL Unreflected HEU Metal Sphere
Margaret A. Marshall, John D. Bess
Idaho National laboratory
Thomas M. Murray
University of Utah
In 1971 and 1972 experimenters at the Oak Ridge Critical Experiment Facility performed critical experiments
using an unreflected metal sphere of highly enriched uranium (HEU). The sphere used for the
criticality experiments, originally used for neutron leakage spectrum measurements by General Atomic
Company, consisted of three main parts and were assembled with a vertical assembly machine. Two configurations
were tested. The first was nearly spherical with a nominal radius of 3.467 inches and had a
reactivity of 73.1 ± 2.0 cents. The sphere parts were then re-machined as a sphere with a nominal radius
of 3.4425 inches. This assembly had a reactivity of -23 cents. When 16 surface mass adjustment buttons
were added the reactivity of the 3.4425-inch-nominal-radius sphere the reactivity was increased to 12.4
cents. The method, dimensions, and uncertainty of the critical experiment were extensively recorded and
documented. The original purpose of the experiments was for comparison to GODIVA I experiments. The
ORNL unreflected HEU Metal Spheres have been evaluated for inclusion in the International Handbook
of Evaluated Criticality Safety Benchmark Experiments (expected to be in the September 2013 edition).
CE 3 2:20 PM
Characterization of the CALIBAN and PROSPERO Critical Assemblies Neutron
Spectrums for Integral Measurements Experiments
P. Casoli, N. Authier and X. Jacquet
Commissariat à l’Energie Atomique et aux Energies Alternatives, CEA, DAM, VALDUC, F-21120 Is sur
Tille, France
J. Cartier
Commissariat à l’Energie Atomique et aux Energies Alternatives, CEA, DAM, DIF, Bruyères-le-Châtel,
F-91297 Arpajon, France
CALIBAN and PROSPERO are two metallic critical assemblies managed by the Criticality, Neutron Science
and Measurement Department located on the French CEA Research Center of Valduc. Both cores are
made of highly enriched uranium alloys. PROSPERO core is surrounded by a depleted uranium reflector.
Each reactor is composed of two cylindrical blocks which can be placed in contact and of four control rods
which allow the reactor to be driven and to reach delayed criticality. CALIBAN and PROSPERO assemblies
are suited for integral measurements in fission neutron spectrums: in particular, each reactor is fitted
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