Structural Analysis on the Hot Plenum Design of Experimental Power Reactor (Farisy Yogatama Sulistyo1,a, Roziq Himawan2, Ari Nugroho3, Syaiful Bakhri1, SriSudadiyo1)

Abstract. The bottom reflector plays an important role in the internal core structure of Experimental Power Reactor (RDE).
However, it must be able to bear the load either the pebbles that is situated inside the core reactor and from its self-load. The
Bottom reflector has column to distribute helium gas from small hole in the cone shaped to through the larger hole in the hot gas
chamber. This column, known as hot plenum, is a simple column that consist of circular graphite block. However, this type
of structure is vulnerable to collapse. Therefore, this paper will simulate the strength of the bottom reflector based on height of
the graphite block that corresponds to the load and analyse Factor of Safety (FOS) to predict the bottom reflector safety. The
higher FOS value mean the design is safe. This simulation employs finite elements method under the SolidWork software. The
models of hot plenum are named H.250mm, H.200mm, H.150mm, H.100mm and H.50mm, which resulting the minimum FOS
of 40.782, 40.891, 41.374, 42.257, 43.394, respectively. Based on calculation among these results, model H.50mm has the
maximum value of FOS. This result will be benefit for Experimental Power Reactor design criteria of failure, the design brittle
fracture behavior, and the design material selection.
Keywords: internal ceramics, factor of safety, brittle material, structural stress, hot plenum HTGR