Abstract Canadian Nuclear Laboratories (CNL) has many decades of thoria research and development experience, including fabrication, irradiation testing, and post–irradiation examination. CNL has previously shown fission gas release (FGR) to be dependent on fuel microstructure in thoria fuels. Lower density fuel with large granules surrounded by porous regions results in higher FGR. Higher and more uniform density fuel results in superior FGR results in thoria fuels with a similar irradiation history. In this paper, this effect of fuel microstructure on FGR is shown empirically using the most recent post–irradiation examination (PIE) results of CNL’s DME-176 and DME-221 thoria experiments. Previously reported PIE results of CNL’s BDL-422 and DME-221 thoria experiments are also compared.

中文翻译：

---

评估燃料微观结构对钍裂变气体释放影响的实验测量

摘要 加拿大核实验室 (CNL) 拥有数十年的钍研发经验，包括制造、辐照测试和辐照后检查。CNL 先前已表明裂变气体释放 (FGR) 取决于钍燃料中的燃料微观结构。具有被多孔区域包围的大颗粒的低密度燃料导致更高的 FGR。在具有相似辐照历史的钍燃料中，更高和更均匀密度的燃料导致优异的 FGR 结果。在本文中，燃料微观结构对 FGR 的这种影响使用 CNL 的 DME-176 和 DME-221 钍实验的最新辐照后检查 (PIE) 结果以经验方式显示。之前报道的 CNL 的 BDL-422 和 DME-221 钍实验的 PIE 结果也进行了比较。