JOURNAL OF ISOTOPES

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Separation of Fission Molybdenum from Low Enriched Uranium Products by Precipitation with α-Benzoin Oxime

WANG Qing-gui;LIANG Ji-xin;WU Yu-xuan;XIANG Xue-qin;LUO Zhi-fu   

  1. Department of Isotope, China Institute of Atomic Energy, Beijing 102413, China
  • Online:2016-11-20 Published:2016-11-21

α-安息香肟沉淀法分离低浓铀裂变产物中的钼

王清贵;梁积新;吴宇轩;向学琴;罗志福   

  1. 中国原子能科学研究院 同位素研究所,北京102413

Abstract:

To separate molybdenum-99 from fission products of low enriched uranium (LEU) by precipitation with α-benzoin oxime (α-BO), influences of temperature, concentration of nitrate, molar ratio of α-BO to Mo, radiation dose and uranium concentration on precipitating molybdenum with α-BO had been evaluated. Re-dissolution of MoO2(α-BO)2 was performed. The decontamination factors of impurity elements including strontium、 zirconium、 ruthenium、 cesium、 cerium、 iodine-131 and uranium had been determined. The recovery yield of Mo for the separation procedure was calculated. It showed that, at the room temperature, with 1 mol/L of nitric acid concentration , higher than 2 of molar ratio of α-BO to Mo, when α-BO was dissolved in anhydrous ethanol or 0.4 mol/L sodium hydroxide solution, higher than 95% of Mo recovery yield could be obtained. Under the radiation dose rate of 5 000 Gy/h, when the radiation dose increased, Mo recovery yield decreased instead. When the total radiation dose of α-BO was below 8.25×105 Gy, Mo recovery yield was higher than 85%.When uranium concentration increased, Mo recovery yield decreased. MoO2(α-BO)2 precipitate could be dissolved in sodium hydroxide of 0.5 mol/L within 15 minutes. Effective decontamination for all major impurity elements including strontium, zirconium, ruthenium, cesium,cerium, iodine and uranium were observed. This study has paved the pay for further research for fission 99Mo production.

Key words: low enriched uranium, α-benzoin oxime, precipitation, separation, fission molybdenum

摘要:

为研究α-安息香肟(α-BO)沉淀法从低浓铀裂变产物中提取裂变99Mo工艺,考察了α-BO沉淀法提取99Mo的条件,包括温度、HNO3浓度、α-BO与Mo摩尔比、辐照剂量、U浓度对α-BO沉淀Mo的影响,探索了MoO2(α-BO)2沉淀的再溶解条件,测定了α-BO沉淀法对131I、Sr、Zr、Ru、Cs、Ce、U等杂质元素的去污系数,以及Mo回收率。结果表明,在室温下,当HNO3浓度为1 mol/L,α-BO与Mo摩尔比大于2时,在无水乙醇和0.4 mol/L NaOH两种α-BO溶解体系下,Mo回收率均大于95%。保持辐照剂量率为5 000 Gy/h,α-BO沉淀法提取Mo的回收率随α-BO辐照剂量的增大而降低。辐照剂量低于8.25×105 Gy时,两种α-BO溶解体系下,Mo回收率均大于85%。随着U浓度的上升,Mo回收率逐渐下降。MoO2(α-BO)2沉淀可在15 min内溶于0.5 mol/L NaOH溶液中。以上结果表明,采用α-BO沉淀法分离靶件溶解模拟液时,对Sr、Zr、Ru、Cs、Ce、I、U等杂质元素有较好的去污效果。研究结果可为低浓铀生产裂变99Mo提供参考。

关键词: 低浓铀, &alpha, -安息香肟, 沉淀法, 分离, 裂变钼