Transient thermal-hydraulic experiments: N-Reactor inlet connector break

An N-Reactor inlet connector piping break was investigated in a laboratory study to determine the effect of this break on the affected process tube`s thermal-hydraulic performance. A full-scale mock-up of the piping between the inlet and outlet risers was used which included actual reactor valves and fittings. An electrically heated half-length section which was equivalent to the downstream half of the reactor fuel column was used to model the heat-generating portion. The simulation of the connector break at the inlet riser was made possible by actuation of high-speed valves. Six runs were made for these tests. Two runs were at 350 psi with initial flow rates of 47,000 lb/hr and test section powers of zero and 1,250 kw. Four runs were made at 1,400 psi with initial flow rates of 85,000 lb/hr and test section powers of zero and 2,500 kw. During two of these runs at 1,400 psi, the butterfly valve was closed to its stop during the flow reversal with scram delays of 1.5 and 5.0 seconds between the time of the ``connector break`` and the start of power reduction. Experimental results are given.