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Ohno, Shuji; Matsuki, Takuo*
JNC TN9400 2000-106, 132 Pages, 2000/12
Sodium fire analyses were performed on 7 kinds of sodium leak tests using a computer code ASSCOPS which has been developed to evaluate thermal consequences of sodium leak accident in an FBR plant. By the comparison between the calculated and the test results of gas pressure, gas temperature, sodium catch pan temperature, wall temperature, and of oxygen concentration, it was confirmed that the ASSCOPS code and the parameters used in the analysis give valid or conservative results on thermal consequences of sodium leak and fire.
; ; Tanabe, Hiromi; Ohno, Shuji; Miyake, Osamu;
PNC TN9410 97-030, 93 Pages, 1997/04
A sodium fire analysis code, ASSCOPS(Analysis of Simultaneous Sodium Combustions in Pool and Spray) was developed coupling the computer codes of SPRAY-IIIM and SOFIRE-MIl to assess temperature-pressure transients resulting from sodium spray and pool combustions, simultaneously. The validation of ASSCOPS was conducted using the experimental results obtained from sodium spray fire experiments using 21 m
vessel and the accuracy of calculated results was discussed. The following results were obtained: (1)Study under inert gas atmosphere. The comparison between analysis and experiment with regard to the pressure and the temperature showed a good agreement. (2)Study under air atmosphere. The comparison between analysis and experiment with regard to the pressure and the temperature also showed a good agreement. (3)Effects of parameter used in evaluating the design of Monju. The peak pressure and temperature obtained by the analysis overestimates the experimental results. From these results, it was concluded that the development and validation of ASSCOPS indicate a improvement on the burning and the heat transfer models in SPRAY-IIIM.
*; *; Himeno, Yoshiaki; Haga, Kazuo*; Miyake, Osamu; *; *
PNC TN9410 90-119, 58 Pages, 1990/03
With a view to giving reasonable requirements for design of containment features in a large LMFBR, this study discusses the following issues: selection of representative events considered in the safety design/evaluation, consideration of the effect of sodium on FP retention in the "Hypothetical Accident" (site evaluation accident), and evaluation of safety margin against beyond-design-basis events. This report contains some technical documents which are provided to the study group meeting.
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.
Morii, Tadashi*; *; *
PNC TN9410 86-124, 61 Pages, 1986/12
PNC-TN9410-86-124.pdf:3.08MBPNC-TN9410-86-124TR.pdf:3.23MB
On Sept. 27, 1985, a large scale sodium spray fire test (RUN-E1) has been conducted in an air atmosphere using the SOLFA-2 test vessel (100m made from SUS) of the SAPFIRE facility. The major test conditions are as follows. (Spray Rate : 510 g/sec) (Spray Period : 1800 sec) (Spray Inlet Temperature : 505 
C) (Spray Falling Height : 4 m) As a sodium spray started, the gas pressure and temperature rose rapidly and reached to the maximum values 1.24kg/cm
-g and 700C, respectively, after about 1.2 minutes. The oxygen in the test vessel was consumed completely after 4 minutes. From oxygen consumption rate during this time, burning rate of sodium was calculated to be 160g-Na/sec that was equivalent to about 30% of the sodium spray rate (under the assumption of 100% Na
O production). Many thermo-couples installed in a spray corn region have been failed due to their exposure to the high temperature above 1000 C, which suggested the existence of a burning zone around the sodium droplets. No remarkable distribution of oxygen concentration was observed in the vertical direction of the vessel during a spray, indicating that the gas within the vessel was well mixed by natural convection due to gas temperature difference between the outside and the inside of a spray corn. Aerosol concentratian has reached the maximum value of 17.5g-Na/m after 5 min and decreased below 1 g-Na/m after 20 min.