Neutronics, Shielding, and Activation Analyses
The three closely coupled activities include:
- Three-dimensional modeling using DAG/MCNP interface
- Neutron streaming through gaps and penetrations
- Neutron wall loading profile
- Optimal radial build, dimension, and composition
- Breeding potential of candidate blankets
- Radiation damage and service lifetime of structural components
- Optimal shield design to protect vital components (such as magnets and vacuum vessel)
- Activation level and decay heat for LOCA/LOFA assessments
- Waste management approaches (disposal, recycling, or clearance)
- Radiation dose around plant for maintenance activity
- Bioshield design for personnel protection during operation
- Integration of nuclear activity with economics and safety activities.
In the area of radiation shielding, we developed an optimization methodology
and a cost-effective shielding concept that have been adopted internationally
by numerous European and Japanese fusion designs. Our recent activation analysis
placed UW as the leading U.S. institute for
radwaste management assessments.
These activities drew the attention of our colleagues in Europe, South Korea and Japan,
requesting collaboration with UW in this unique area of research.
Recognizing the importance of the accurate estimation of the tritium
breeding ratio (TBR), we couple the CAD model with MCNP via the
DAG-MCNP code, permitting faster implementation of design changes
and iterations.
We developed in the late 1980s a simple scheme to
estimate the overall TBR based on 1-D analysis. We defined a new term
called the neutron coverage fraction (NCF), representing the blanket area
fraction weighted by the neutron wall loading distribution. In other words,
it is the fraction of neutrons incident on any FW segment. The overall TBR can
then be estimated by combining the NCF with the 1-D local TBR value. We applied
this methodology to many designs and confirmed our estimate with 3-D analysis.
Comparing the results showed excellent agreement between the simple 1-D,
quick method and the 3-D analysis.
Publications
- ARIES Project
- ITER Project
- APEX Project
- HAPL Project
- Z-Pinch Project
- PPPL Pilot Plant
- CAD-Based Neutronics
- Other Projects