Experiment data report for Semiscale Mod-1 Test S-29-3; integral test from reduced initial pressure. [PWR]

Recorded test data are presented for Test S-29-3 of the Semiscale Mod-1 special heat transfer test series. This test is among several Semiscale Mod-1 experiments conducted to investigate the thermal and hydraulic phenomena accompanying a hypothesized loss-of-coolant accident in a pressurized water reactor system. Test S-29-3 was conducted from an initial cold leg fluid temperature of 544/sup 0/F and an initial pressure of 1,760 psia. A simulated double-ended offset shear cold leg break was used to investigate the system response to a depressurization transient starting from a lower initial pressure than that usually associated with pressurized water reactor operation. System flow was set to achieve a full core fluid temperature differential of 66/sup 0/F at full core power of 1.6 MW. The flow resistance of the intact loop was based on core area scaling. An electrically heated core with a peaked radial power profile was used in the pressure vessel to simulate the effects of a nuclear core. During system depressurization, core power was reduced from the initial level of 1.6 MW to simulate the surface heat flux response of nuclear fuel rods until such time that departure from nucleate boiling might occur. Blowdown to the pressure suppression system was accompanied by simulated emergency core cooling injection into both the intact and broken loops. Coolant injection was continued until testtermination at 200 seconds after initiation of blowdown. The purpose of the report is to make available the uninterpreted data from Test S-29-3 for future data analysis and test results reporting activites. The data, presented in the form of graphs in engineering units, have been analyzed only to the extent necessary to assure that they are reasonable and consistent.