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Morii, Tadashi*; Himeno, Yoshiaki
PNC TN9410 87-006, 51 Pages, 1987/01
In the study, the test results from SOLFA-2 of the SAPFIRE facility were used. But, the calculated results using the standard input data underestimated the test results. So, the other calculations by changing the following parameter were conducted. (1)Burning rate constant of a sodium droplet. (2)Gas buoyant force. (3)Pool burning effect. (4)E㎜isivity of aerosol containing gas. (5)Spray droplet size. Changing the above parameter from (1) to (4) did not make any significant improvement, in other words, the results still underestimated the test results. But, changing of the (5)parameter improved the calculated results. However, the best estimated results was with a spray droplet whose size is a half of a real one.
Himeno, Yoshiaki; ; Kawada, Koji*; Kawabe, Ryuhei*; *; *; Miyaguchi, Kimihide
PNC TN941 85-130, 65 Pages, 1985/09
Test of sodium fires in an auxiliary building of the fast reactor has been conducted by use of a test rig in which reduced scale models of a sodium pipe, a floor liner, a sodium drain pipe, and a smothering tank were installed to simulate the configuration of fire mitigation systems in the reactor. In the test, a 150kg sodium at temperature of 505 
C was spilled from the model sodium pipe at flow rate of 1 
/sec for 3 minutes. Then a whole accident sequence that starts from a sodium spill and ends at a self-extiguishment of fire within the smothering tank was studied. From the test results obtained and through their analysis, the following conclusions were drawn. (1)A whole sodium leak and fires accident sequence proceeded as expected in the Monju design, i,e., a spilled sodium was smoothly drained into the smothering tank via the floor liner and the drain pipe, then sodium fire was self-extinguished in the smothering tank. (2)In regard to the model sodium pipe, failures of the thermal insulation jackets due to sodium corrosion and due to generated sodium combustion heat are not found. The thermal insulation jackets kept its original geometries and functioned propely as a barrier to prevent the dispersion of spilled sodium into the atmosphere during the test. No flow blockage of a spilled sodium occured both on the floor Liner and in the drain pipe. Combustion heat of mixed fires (a columnar fire and a pool fire) that occured within an accident cell of the test rig was determined to be 1.6 times of that of a pool fire. This value is not so large as expected and indicates that the mild fires proceeds during the test. (3)With the smothering tank, temperatures data of sodium, steel liner, perlite concrete, and structural concrete were obtained. The data of concretes indicated that the structural concrete was not heated so high as to interfere its structural integrity. A total water released from the concretes per unit surface area of the liner ...
Kawabe, Ryuhei*; Himeno, Yoshiaki; *; *; *
PNC TN941 84-124, 56 Pages, 1984/08
At Sodium Leak-Fire Basic Test Rig (SOFT-1), three tests were performed, which were : (1)Run-A1 : For the aim of understanding the sodium combustion phenomena, 180 sodium was burnt in an open pool, and temperature transients in sodium was measured and burning rate were determined. (2)Run-B1 : For the evaluation of efficiency of fire suppression board, burning sodium was covered by a slitted board and change in burning rate was observed and drain test was performed using 530 C sodium to confirm the function and integrity of draining pipe. (3)Run-B2 : In order to clarify the burning-hydraulic behavior of sodium on liner, 505C, 180 sodium was discharged onto 1.2m
2.4m steel plate with 1/100 gradient, and temperature transients and mass of residuum were measured. Following results were obtained. (i)When sodium was heated up to 400C and exposed to air, the sodium was ignited. (ii)The surface temperature reached 650 C, 7 min. after the ignition and the temperature was almost constant from that. (iii)Under a conservative condition where air flowed over the fire suppression board by forced convection, the sodium burning rate and the aerosol generating rate where pool surface were covered by fire suppression board (opening area 1%) was about 3 % and 5 % of those in open pool burning respectively. (iv)The maximum heat flux to the draining pipe wall reached 1.210
W/m
. Any cracking, however, was not found on the draining pipe wall even by color check. (v)In the liner test Run-B2, on the liner there remained large amount of sodium oxide, which worked as wick, and the soaked sodium burned after sodium supplying finished, resulting liner temperature 643 C which was higher than the supplied sodium temperature. The amount of sodium oxide was 8.7kg/m on the liner after the test. (vi)The maximum temperature, flow velocity and burning rate of sodium on liner and maximum heat ...
