Table 2.

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

a
Material Type	Estimated thicknesses of material between Location A and NRU reactor core (cm)
Water	45
Steel	45
High-density concrete	700

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

a indicates that Location A was two floors below the NRU reactor core, within the reactor building

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