Delayed settling of the ash particles and poor drainage of water from the pond ash are the major problems faced during the hydraulic stowing of pond ash. In this study the effect of polymeric flocculant on settling of...Delayed settling of the ash particles and poor drainage of water from the pond ash are the major problems faced during the hydraulic stowing of pond ash. In this study the effect of polymeric flocculant on settling of the ash particles and drainage of water during pond ash stowing are investigated. In addition, the parameters, viz. drainage and absorption of water during pond ash stowing are quantified by stowing a mine goaf model with pond ash slurries of five different concentrations added with and without flocculant. The study revealed that addition of only 5 10 6 of Sodium Carboxymethyl Cellulose (Na-CMC) flocculant with the pond ash slurries during stowing offers best result in terms of quicker settling of the ash particles and enhanced water drainage from the hydraulically stowed pond ash. Besides, it resulted in drainage of more than 85% of the total water used in the initial 45 min of stowing. The improvement in drainage is caused due to coagulation and flocculation of the pond ash particles because of charge neutralization and particle-particle bridging. This study may provide a basis for estimating the drainage and absorption of water during the real pond ash stowing operation in underground mines.展开更多
The LIVE （Late In-Vessel Phase Experiments） test program investigates in-vessel melt pool behaviour and cooling strategies for in-vessel corium retention during severe accidents in light water reactors （LWR）. The ...The LIVE （Late In-Vessel Phase Experiments） test program investigates in-vessel melt pool behaviour and cooling strategies for in-vessel corium retention during severe accidents in light water reactors （LWR）. The main part of the LIVE facility is a 1：5 scaled semi-spherical lower head of a typical pressurized water reactor. Up to now, LIVE experiments have been performed in different initial external cooling conditions, melt volumes and internal heat generations. At present the well-known simulant material KNO3-NaNO3 in non-eutectic composition （80 mole% KNO3-20 mole% NaNO3） and in eutectic composition （50 mole% KNO3- 50 mole% NaNO3） is used in the live program. The 3D heat flux distribution through vessel wall, melt pool temperature, crust thickness and the pool melt composition can be measured or determined. Extensive results have been obtained concerning the melt pool thermal hydraulic behaviour in transient and in steady state conditions.展开更多
文摘Delayed settling of the ash particles and poor drainage of water from the pond ash are the major problems faced during the hydraulic stowing of pond ash. In this study the effect of polymeric flocculant on settling of the ash particles and drainage of water during pond ash stowing are investigated. In addition, the parameters, viz. drainage and absorption of water during pond ash stowing are quantified by stowing a mine goaf model with pond ash slurries of five different concentrations added with and without flocculant. The study revealed that addition of only 5 10 6 of Sodium Carboxymethyl Cellulose (Na-CMC) flocculant with the pond ash slurries during stowing offers best result in terms of quicker settling of the ash particles and enhanced water drainage from the hydraulically stowed pond ash. Besides, it resulted in drainage of more than 85% of the total water used in the initial 45 min of stowing. The improvement in drainage is caused due to coagulation and flocculation of the pond ash particles because of charge neutralization and particle-particle bridging. This study may provide a basis for estimating the drainage and absorption of water during the real pond ash stowing operation in underground mines.
文摘The LIVE （Late In-Vessel Phase Experiments） test program investigates in-vessel melt pool behaviour and cooling strategies for in-vessel corium retention during severe accidents in light water reactors （LWR）. The main part of the LIVE facility is a 1：5 scaled semi-spherical lower head of a typical pressurized water reactor. Up to now, LIVE experiments have been performed in different initial external cooling conditions, melt volumes and internal heat generations. At present the well-known simulant material KNO3-NaNO3 in non-eutectic composition （80 mole% KNO3-20 mole% NaNO3） and in eutectic composition （50 mole% KNO3- 50 mole% NaNO3） is used in the live program. The 3D heat flux distribution through vessel wall, melt pool temperature, crust thickness and the pool melt composition can be measured or determined. Extensive results have been obtained concerning the melt pool thermal hydraulic behaviour in transient and in steady state conditions.
