Neutronics investigations for helical DEMO reactor FFHR-d1

Abstract

Radiation shielding and tritium breeding performances of the helical DEMO reactor FFHR-d1 have been investigated for the present proposed reactor component configuration. Since the core plasma position shifts to inboard side of the torus, the total thickness of the inboard breeding blanket and radiation shield of FFHR-d1 is limited to ~70 cm. To simulate the geometric features of the helical reactor, three-dimensional neutronics calculation model consisted of ~4,000 cells have been prepared for the neutron and gamma-ray transport calculations using the MCNP code. It has been confirmed that the present radiation shield configuration with WC (tungsten carbide) and FS (ferritic steel) + B4C layers would provide sufficient shielding performance for the helical coils. The tritium breeding ratio (TBR) of 1.08 has been obtained with a Flibe+Be/FS breeding blanket for the present component configuration of FFHR-d1. © 2012 The Japan Society of Plasma Science and Nuclear Fusion Research.