Experimental investigation of the hot water layer effect on upward flow open pool reactor operability

الملخص EN

The open pool reactor offers a high degree of reliability in the handling and manoeuvring, the replacement of reactor internal components and the suing of vertical irradiation channels.

The protection of both the operators and the reactor hall environment against radiation hazards is considered a matter of interest.

So, a hot water layer is implemented above many of the research reactors main pool, especially those whose flow direction is upward flow.

An experimental work was carried out to ensure the operability of the upward flow open pool research reactor with / without the hot water layer.

The performed experiment showed that, the hot water layer is produced an inverse buoyant force make the water to diffuse downward against the ordinary natural circulation from the reactor core.

An upward flow - open pool research reactor (with a power greater than 20 Mwatt) could not wok without a hot water layer.

The high temperature of the hot water layer surface could release a considerable amount of water vapour into the reactor hall, so a heat and mass transfer model is built based on the measured hot water layer surface temperature to calculate the amount of released water vapour during the reactor operating period.

The effects of many parameters like the ambient air temperature, the reactor hall relative humidity and the speed of the pushed air layer above the top pool end on the evaporation rate is studied.

The current study showed that, the hot water layer system is considered an efficient shielding system against Gamma radiation for open pool upward flow reactor and that system should be operated before the reactor start up by a suitable period of time.

While, the heat and mass transfer model results showed that, the amount of the released water vapour is increased as a result of both the increase in hot water layer surface temperature and the increase in air layer speed.

As the increase in hot water layer surface temperature could produce a good operability conditions from reactor safety point of view, it could harms the reactor hall walls paint and some components due to the condensation of water vapour.