Abstract Fission fragments emitted in a fissile solution create tiny gas bubbles, the size of which is determined by the linear energy transfer (LET) of the particles. The LET of fission fragments of 235U in aqueous solutions of uranyl nitrate has been determined, and using methods adapted from the literature, the size of gas bubbles generated along the tracks of these particles has been estimated, revealing important variations with respect to particle LET and solution properties. Empirical correlations are presented for the maximum radius of radiolytic gas bubbles in unsaturated solutions of uranyl nitrate as a function of solution temperature and concentration. These can be used to predict the critical concentration of dissolved hydrogen necessary for the appearance of gas voids during nuclear criticality transients. The findings are intended for use in a future model of nuclear criticality transients in aqueous fissile solutions for the purposes of nuclear criticality safety assessment.

中文翻译：

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235U裂变碎片的线性能量转移和硝酸铀酰水溶液中气泡的成核

摘要 裂变溶液中释放的裂变碎片会产生微小的气泡，气泡的大小由粒子的线性能量转移 (LET) 决定。已经确定了硝酸铀酰水溶液中 235U 裂变碎片的 LET，并使用改编自文献的方法估计了沿这些粒子轨迹产生的气泡的大小，揭示了粒子 LET 和溶液性质。给出了硝酸铀酰不饱和溶液中辐射分解气泡的最大半径与溶液温度和浓度的函数关系的经验相关性。这些可用于预测在核临界瞬变期间出现气体空隙所需的溶解氢的临界浓度。