Source Term Derivation and Radioactive Release Evaluation for JRTR Research Reactor under Severe Accident

Table 1

Design characteristics of the JRTR research and training reactor.

Reactor type	Tank-in-pool
Nominal thermal power (MW)	5
Max thermal flux (n/cm^2 s)	1.7 × 10^14
No. of fuel assemblies	18
Fuel material	U3Si2
Uranium enrichment (wt)	19.75%
No. of control elements (box shape)	4
Control plate material	Hafnium
Moderator	Light water
Internal reflector	Beryllium
External reflector	Heavy water
Coolant (flow direction)	Light water (downward)
Coolant inlet temperature (°C)	37.0
Water channel thickness (mm)	2.35
Water channel thickness between two fuel elements (cm)	0.390
Max. heat flux (W/m^2)	1,170,000
Nominal flow rate (m^3/h)	612
Average core flow velocity (m/s)	2.5
Core inlet pressure (MPa)	0.18