Thermal-hydraulic Fortran program for steady-state calculations of plate-type fuel research reactors

Abstract

The safety assessment of research and power reactors is a continuous process covering their lifespan and requiring verified and validated codes. Power reactor codes all over the world are well established and qualified against real measuring data and qualified experimental facilities. These codes are usually sophisticated, require special skills and consume a lot of running time. On the other hand, most research reactor codes still require much more data for validation and qualification. It is, therefore, of benefit to any regulatory body to develop its own codes for the review and assessment of research reactors. The present paper introduces a simple, one-dimensional Fortran program called THDSN for steady-state thermal-hydraulic calculations of plate-type fuel research reactors. Besides calculating the fuel and coolant temperature distributions and pressure gradients in an average and hot channel, the program calculates the safety limits and margins against the critical phenomena encountered in research reactors, such as the onset of nucleate boiling, critical heat flux and flow instability. Well known thermal-hydraulic correlations for calculating the safety parameters and several formulas for the heat transfer coefficient have been used. The THDSN program was verified by comparing its results for 2 and 10 MW benchmark reactors with those published in IAEA publications and a good agreement was found. Also, the results of the program are compared with those published for other programs, such as the PARET and TERMIC

Lumped parameter model for the safety assessment of the IAEA 10MW benchmark reactor during a protected loss of flow accident

“…Before going forward in our study, in this section, a verification of the correlations used to evaluate the safety criteria, ONBR, OFIR, DNBR and BOR is performed separately, throughout the uses of steady state solution. So, after we have calculated the different safety criteria, thereafter is compared with the results of Khedr (2008), as given in tables 1 and 2.…”

“…In table 1, we present a comparison between the average heat fluxes of our calculation with those of Khedr (2008) at steady conditions, where a significant difference between both results is noticed may be due to the difference of used correlations.…”

“…For a given plate assembly there is a critical flow velocity at which the plates become unstable and large deflections of the plates can occur. To avoid that, the coolant velocity of coolant should verify the following condition, Khedr (2008),…”