Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (3): 559-565.doi: 10.3866/PKU.WHXB201501092

• PHOTOCHEMISTRY AND RADIATION CHEMISTRY • Previous Articles     Next Articles

Effect of HNO3 on the γ Radiolysis and Radiolytic Liquid Products of N, N-Dimethylhydroxylamine

WANG Jin-Hua1, CAO Xiao-Jun1, LI Chun1, WU Ming-Hong1, BAO Bo-Rong1, ZHENG Wei-Fang2, HE Hui2, ZHANG Sheng-Dong2   

  1. 1. Shanghai Applied Radiation Institute, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, P. R. China;
    2. Radiochemistry Department, China Institute of Atomic Energy, Beijing 102413, P. R. China
  • Received:2014-09-23 Revised:2015-01-09 Published:2015-03-06
  • Contact: WANG Jin-Hua
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20771074, 11025526) and Program for Innovative Research Team in University, China (IRT13078).


N,N-dimethylhydroxylamine (DMHA) is a novel salt-free reductant used for the separation of U from Pu and Np in the reprocessing of spent fuel. We investigated the effect of HNO3 on the radiolysis of DMHA and its radiolytic liquid product. Results show that 0.1 and 0.5 mol·L-1 DMHA containing 0.3-1.0 mol· L-1 HNO3 have good radiation stability at a reasonable dose level during the U/Pu separation cycle and the Pu purification cycle. For 5-25 kGy the main radiolytic liquid products are N-methyl hydroxylamine, HCHO, HCOOH, and HNO2. The concentration of these organic compounds is much higher than that of HNO2 and increases with both HNO3 concentration and absorbed dose. At the same HNO3 concentration and dose, the concentration of N-methyl hydroxylamine in irradiated 0.1 mol·L-1 DMHA-HNO3 is higher than that in irradiated 0.5 mol·L-1 DMHA-HNO3. However, the HCHO concentration in 0.1 mol·L-1 DMHA-HNO3 is lower than that in 0.5 mol·L-1 DMHA-HNO3. The HCOOH concentration in 0.1 mol·L-1 DMHA-HNO3 is higher than that in 0.5 mol·L-1 DMHA-HNO3 at higher HNO3 concentrations. The relationship of HNO2 concentration with HNO3 concentration and dose depends on the original DMHA and HNO3 concentrations.

Key words: N,N-dimethyl hydroxylamine, Nitric acid, γ-Radiolysis, Radiolytic liquid product, Reprocessing of spent fuel