Pu(Ⅲ)光氧化工艺研究

摘要: 对Ｐｕｒｅｘ工艺流程中ＩＢＰ和２ＢＰ混合液流进行了紫外光照射，实现了Ｐｕ（Ⅲ）光氧化至Ｐｕ（Ⅳ）的“无盐”调价过程。光照７．５ｈ可使Ｐｕ（Ⅲ）全部氧化成Ｐｕ（Ⅳ），Ｐｕ（Ⅵ）含量＜１％，继续光照２．５ｈ仍能控制Ｐｕ（Ⅵ）含量＜７％。研究了Ｐｕ、ＨＮＯ＿３、Ｆｅ￣（２＋）浓度以及光源功率、温度变化对Ｐｕ（Ⅲ）光氧化的影响。结果表明：在Ｆｅ￣（２＋）和浓度基本维持恒定的情况下，Ｐｕ从０．３０ｇ／１、０．６６ｇ／１增至１．１４ｇ／１，ＨＮＯ＿３从１．５ｍｏｌ／ｌ增至２．７ｍｏｌ／ｌ，对Ｐｕ（Ⅲ）光氧化基本无影响；在相同条件下，光源功率增大，温度升高，Ｐｕ（Ⅲ）光氧化时间减少。此外，还对光照后溶液中Ｐｕ价态稳定性与放置时间的关系，进行了５次１０天的跟踪测定。结果表明，Ｐｕ的价态在１０天内基本稳定。

Abstract: STUDY ON PHOTOOXIDATION OF PLUT0NIUM（Ⅲ）0F 1BP IN PUREX PROCESSZHOU ZHIHONG; HU JINGXIN; DUAN YUNFU; ZHANG XIANYE（China Institutei of atomic Energy，P. O. Box 275（26），BEIJING 102413）XIE XUEYI; JIA RUIHE; WANG SHUIXIANG（Lanzhou Nuclear Fuel Complex，Lanzhou 732850）ABSTRACT Bench scale of photcooxidation plutonium（Ⅲ）of 1BP to plutonium（Ⅳ）in Purex processinstead of adding sedium nitrite has been achieved by UV Iight irradiation. The alternative tech-nology can realize so-called solt-free process. The about 99％of plutonium（Ⅲ） is oxidized to plu-tonium（Ⅳ） at 7．5h，but plutonium（Ⅵ）is less than 1％，extending 2．5h of irradiation，less than7％plutonium（Ⅵ）can be controled．The effects of concentration of plutonium ，nitric acid andferrous ion and of power of light source and of temperature on photooxidation of plutonium（Ⅲ）have been investegated．The results show that，in the constant conditions of concentration of fer-rous ion and hydrazine，changing concentration of plutonium from 0．30，0．66 to 1.14g/1，concen-tration of nitric acid from 1．5 to 2．7 mol／l，the photcoxidation of plutonium（Ⅲ） is not effected.In the same conditions，the time of photcoxidation of plutonium（Ⅲ）decreases with the increaseof power of light source and with increase of temperature. In addition，the effects of keeping timeof solution irradiated on the change of valence of plutonium have been observed． The results showthat the valence of plutonium dose not change in ten days.Key words Photcoxidation Pu（Ⅲ）Purex process Salt-free process