Steady state thermal hydraulics analysis of GHARR-1 using the pl temp/anl v 4.0 code

Thermal-hydraulics analysis of the Ghana Research Reactor-1 (GHARR-1) has been carried out. The reactor consists of an assembly of 344 HEU vertical fuel rods cooled by natural convection. The Steady State thermal-hydraulics Analysis of the axial temperature distributions of the fuel rods, cladding surface and coolant channels in a sub-cooled boiling regime using the PLTEMP/ANL v 4.0 code has been modeled. External coupling of the Monte Carlo N Particle version 5 (MCNP5) Code provided the axial power peaking factors that sufficed the entire modeling process. At a steady state inlet temperature of 30°Celsius and pressure of 0.1237 MPa, the peak fuel and clad surface temperatures were predicted to be 110.55°Celsius and 104.25°Celsius respectively which are all below the eutectic temperature of the U-Al alloy i.e. (640°Celsius). The maximum outlet coolant temperature was predicted to be 50°Celsius giving a coolant temperature rise of 20°Celsius. Standard correlations in the PLTEMP/ANL code was used to compute the various axial properties of the fuel rods such as: coolant flow rates, coolant velocity, density, pressure drop, heat fluxes, fractional powers per rod at the margins to Onset-of-Nucleate Boiling (ONB), Minimum Departure from Nucleate Boiling ratio (MDNBR) and the Minimum Flow instability Power ratio (FIR). Most of the model predictions in this study were consistent with experimental results in the Safety Analysis Report (SAR). Outcomes of the research certify that GHARR-1 can be operated at a steady state thermal power of 30kW without compromising on safety. (au)