Program - Brookhaven National Laboratory

• Recent developments on data evaluation tools, particularly to include uncertainty and covariance
matrices, as well as updates of simulation tools to facilitate the regular use of these covariances in
standard problems,
• Comparisons of new calculation tools, data and codes, with criticality and experimental reactor
benchmarks as well as with dedicated integral experiments, and feedback to evaluators and measurement
programs,
• Recent validation of high energy reaction models, new data from neutrons beyond 100 MeV and
progress in the high energy reactions models for improving accuracy and extending the energy range
of applicability.
Finally an outlook of the additional results expected by the end of the project will also be included.
Session CF Fission Yields
Monday March 4, 2013
Room: Central Park East at 1:30 PM
CF 1 1:30 PM
Fission Product Yields for Fast and 14 MeV Neutrons
M.B. Chadwick
Los Alamos National Laboratory
This poster will summarize recent Los Alamos fission product yield work in experiment [1], theory, and
evaluation [2], that culminated in work we recently incorporated into ENDF/B-VII.1 [3]. The poster will
focus on describing recent developments in experiment, and theory, since we published our results, and will
describe how these works relate to our recent ENDF/B-VII.1 evaluations. There are 2 main questions we
are trying to settle through additional work: (1) We proposed energy dependencies for plutonium FPY over
the fast neutron energy region, from 0.5 - 2 MeV. These are needed to accurately infer plutonium burnup
from fission product measurements; (2) There are systematic differences in the magnitude of key FPY
for plutonium. Although Livermore’s recent evaluations now agree with LANL’s, the CEA measurements
from Laurec et al still show a 5-10% systematic difference with the US data. We are trying to resolve
this discrepancy. The main experimental efforts being pursued are at TUNL (Triangle University Nuclear
Laboratory) - a collaboration between Duke University , LANL, and LLNL; at LANL (new detectors being
built at LANSCE) and by LANL at the Nevada critical assemblies. This contribution will summarize these
results.
1. H. Selby et al., Nucl Data Sheets 111, 2891 (2010); MacInnes, NDS 112, 3135 (2011) 2. M.B. Chadwick
et al., Nucl Data Sheets 111, 2923 (2010) 3. M.B. Chadwick et al., Nucl Data Sheets 112, 2887 (2010)
CF 2 2:00 PM
Fission Product Yield Study of 235 U, 238 U and 239 Pu Using Dual-Fission Chambers
C. Bhatia, B. Fallin, C. Howell, W. Tornow
TUNL,Duke University,Durham, North Carolina 27708, USA
M. Gooden, J. Kelley
TUNL, North Carolina State University, Raleigh, North Carolina 27695, USA
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