Release behavior of smoke and clogging characteristics of the ventilation filter under the fire accident. Contract research

In a part of building ventilating installation of reprocessing plant, the pre-filter is equipped in front of a HEPA filter. The pre-filter plays a role in protection and repression of clogging of HEPA filter. However, in a fire accident, it is considered that large smoke generation cause the pre-filter clogging due to smoke loading, increase of differential pressure and breakdown. In Japan Atomic Energy Research Institute, the demonstration tests to confirm the performance of ventilation filters by a fire accident were carried out. In the tests, smoke was generated from burning of the mock solid wastes (gloves made of rubber and/or cloth) or the mock recovered solvent (n-dodecane or tributyl phosphate / n-dodecane). The test data was acquired on generation of smoke, decrease evolution of smoke by transportation through the compositions of ventilation system (cell, duct, damper, filters) and clogging characteristics of the ventilation filters due to smoke loading. From the results, it was found that the performance of the whole of ventilation system was kept even if the pre-filter was breakdown. To adopt the analysis of the increase of differential pressure across the pre-filter using the safety analysis code, CELVA-1D, increase of differential pressure across the pre-filter was expressed by quadratic empirical equation with function of smoke loading per unit filtration area and it coefficients, (α, β), were estimated. (author)