Table 2 Intervening shielding/building material between the NRU reactor core and Locations (a) A and (b) B

From: Stand-off nuclear reactor monitoring with neutron detectors for safeguards and non-proliferation applications

a
Material Type Estimated thicknesses of material between Location A and NRU reactor core (cm)
Water 45
Steel 45
High-density concrete 700
  1. a indicates that Location A was two floors below the NRU reactor core, within the reactor building
  2. b indicates that Location B was at ground level outside of the reactor building. The main reactor hall was at ground level, enclosed by the reactor building exterior walls. The main reactor hall surrounded the top and side shielding of the reactor core
b
Material type Estimated thicknesses of material between location b and nru reactor core (cm) main reactor hall top reactor shielding Side reactor shielding Reactor building exterior wall
Water 300 30
Steel 120 30
High-Density Concrete 270 15
  1. a indicates that Location A was two floors below the NRU reactor core, within the reactor building
  2. b indicates that Location B was at ground level outside of the reactor building. The main reactor hall was at ground level, enclosed by the reactor building exterior walls. The main reactor hall surrounded the top and side shielding of the reactor core