Separate effects tests to determine the effective thermal conductivity in the PBMR HTTU test facility

Recent SAM Code Improvement to Heat Transfer Modeling Capabilities

“…The SANA [15] experiment was performed in the 1990s in Germany to demonstrate the passive decay heat removal capability of pebble bed reactor designs, which has been widely used for code benchmark/validation purpose in nuclear reactor thermal-hydraulics community. Later, the HTTU experiment [16] [17] was performed in South Africa to directly investigate the effective thermal conductivity of a prototypical pebble bed.…”

“…The High Temperature Test Unit (HTTU) facility, developed by the PBMR company in collaboration with the North-West University and M-Tech Industrial (Pty) Ltd. in South Africa, is an experiment facility dedicated to study the different thermal-fluid phenomena of pebble bed type of HTGR [17]. A separate effect test has been performed to investigate the effective thermal conductivity of the pebble bed.…”

Effect of scale on the modeling of radiation heat transfer in packed pebble beds

“…In the HTTU test, the natural convection can be neglected and the conduction part of effective thermal conductivity k c is about 2 W/(mÁ°C) [4]. The dependence of conductivity of graphite material on temperature is [3] k s ¼ 186 À 39:54 Â 10 À2 t þ 4:89 Â 10 À4 t 2 À 2:91 Â 10 À7 t 3…”

“…The bed is operated in inert gas (helium or nitrogen) atmosphere and the effect of natural convection cannot be neglected under lower heating power. The HTTU test is another new experiment with negligible natural convection [4]. The facility is filled with nitrogen as interstitial gas and operated under very low pressures.…”

Externally fired gas turbine technology: A review

“…Another design in South Africa was the 400 MW th pebble bed modular reactor (PBMR) reactor with three-shaft magnetic bearing gas turbine [49]. The design was verified with several R&D experimental facilities [50][51][52][53]. However, the EFGT plant was discontinued and redirected to a conventional steam-based cogeneration plant [10].…”