MMW shielding design and analysis
Abstract
Reactor shielding for multimegawatt (MMW) space power must satisfy a mass constraint as well as performance specifications for neutron fluence and gamma dose. A minimum mass shield is helpful in attaining the launch mass goal for the entire vehicle, because the shield comprises about 1 to 2 percent of the total vehicle mass. Also, the shield internal heating must produce tolerable temperatures. Finally, the shield materials must remain physically and chemically stable for the lifetime of the vehicle. Shield performance for neutrons and gammas is studied. The derived heating rates are essential inputs for auxiliary calculations to predict temperature profiles, thermal expansion, thermal stresses, and structural strength. Topics addressed include cross section preparation for multigroup 2D S sub n transport analyses, and the results of parametric design studies on shadow shield performance and mass versus key shield design variables such as cone angle, number, placement, and thickness of tungsten layers, and shield top radius. Finally, adjoint methods are applied to the shield in order to spatially map its relative contribution to dose reduction, and to provide insight into further design optimization.
- Publication:
-
Transactions of the Fifth Symposium on Space Nuclear Power Systems
- Pub Date:
- 1988
- Bibcode:
- 1988snps.symp..409O
- Keywords:
-
- Gamma Rays;
- Neutron Irradiation;
- Radiation Shielding;
- Reactor Design;
- Space Power Reactors;
- Radiation Dosage;
- Structural Stability;
- Structural Weight;
- Temperature Distribution;
- Thermal Expansion;
- Thermal Stresses;
- Tungsten;
- Nuclear and High-Energy Physics