A. Le Coq,
"Design of a Safeguards Instrument for Plutonium Quantification in an Electrochemical Refining System,"
M.S. Thesis, Nuclear Engineering, Texas A&M University, College Station, TX (2013).
There has been a strong international interest in using
pyroprocessing (or electrochemical refining system) to close the
fast nuclear reactor fuel cycle and reprocess spent fuel
efficiently. To commercialize pyroprocessing, safeguards
technologies are required to be developed. In this research, the
use of Self- Interrogation Neutron Resonance Densitometry (SINRD)
has been investigated as a method to safeguard the process and more
precisely quantify the Pu-239 content of pyroprocessing materials.
This method uses a detector array with different filters to isolate
the low-energy resonance in Pu-239 neutron fission crosssection.
The relative response of the different detectors allows for the
quantification of the amount of Pu-239 in the pyroprocessing
The Monte-Carlo N-Particle (MCNP) code was used to design a
SINRD instrument. This instrument is composed of a neutron source
pod and a SINRD detector pod. Experimental measurements were also
performed to validate the MCNP model of the instrument. Based on
the results from simulations and experiments, it has been concluded
that the MCNP model accurately represents the physics of the
experiment. In addition, different SINRD signatures were compared
to identify which of them are usable to determine the fissile
isotope content. Comparison of different signatures allowed for
reduction in the uncertainty of the Pu-239 mass estimate. Using
these signatures, the SINRD instrumentation was shown to be able to
quantify the Pu-239 content of unknown pyroprocessing
Associated Project(s):Design of a Safeguards Instrument for Plutonium Quantification in an Electrochemical Refining System