Development of sodium columnar combustion code SOFIRE-M3

Ohno, Shuji  ; not registered

Conputational code SOFIRE-M3 has been developed to evaluate the thermal consequences which would be brought by the sodium columnar leak and fire accident postulated in the FBRs. New code is the improved version of SOFIRE-MII and has following features. (1)Sodium columnar combustion rate is calculated from the empirical formula which has been derived from the results of Run-E3 test series and has the terms of sodium leak rate, leak height, and oxygen concentration in the atmosphere. (2)Calculational parameters of heat distribution fraction, which determine the reaction heat transferred to both sodium and gas, have been optimized by the post-test calculations of Run-E3 using the SOFIRE-M3 code. The code predicts heat transfer phenomena within 30% of accuracy when the optimized parameters are used. Calculations of large-scale sodium leak and fire tests Run-E2 and Run-D2, which had been performed at the SAPFIRE facility in 1985 and 1986 respectively, showed good agreement between code calculated and measured data. This SOFIRE-M3 code can contribute in the near future to the more optimized designing and safety evaluation of FBR p1ant. Refinement of the empirical formula and improvement of the code remain as future subjects related to the effect of sodium leak rate on the columnar combustion rate.