The combined use of nitric and formic acids, in lieu of formic acid alone, to reduce H-2 emissions during the treatment of high-level radioactive waste sludge was investigated. The H-2 generation can be mitigated substantially by substituting a fraction of formic acid with nitric acid as the required acid source, and then using formic acid as the required reductant source. The peak H-2 generation rate was reduced by more than a factor of 2, and a more gradual rise in the H-2 evolution resulted. However, the addition of mercury to the sludge increased the evolution of H-2 as did increasing the amount of nitric acid used and the rate of addition of the formic acid source. Overall, these results provided clear insight into what controlled the evolution of H-2 from high-level waste sludge and a means of mitigating it. References: 13
展开▼
