A new type of continuous density meter, applicable for use with ThO2 slurry in high temperature-pressure systems, was tested successfully in a low temperature slurry loop.

Some refined calculations have been made, relative to a proposed delay prior to a dump, to determine the expected D2 concentration in the vent stream from the pressurizer gas bleeds during a dump of the Homogeneous Reactor Test (HRT). These calculations indicate that for vent valves have a Cv of 0.07 (venting time from 2000 psia to D2O saturation pressure of approximately 12 minutes), a delay period is not required since the D2 concentration is well below lower explosive limit. For vent valves having a Cv of 0.3 (venting time approximately 2.4 minutes), the calculation indicate that a delay before venting of approximately two minutes will be required. This is due entirely to the possibility of mass ebullition the D2. Since the pressure drops so quickly, the reactor solution becomes saturated with D2 before appreciable recombination can occur.