Abstract Activated cooling water in nuclear facilities can present a significant radiation source around primary cooling system causing radiation damage to electrical components, increasing doses to personnel and in the case of fusion facilities additional heating to superconducting coils. As currently no fusion reactors fusing deuterium and tritium are capable to perform water activation experiments with sufficient accuracy, fission research reactors present an opportunity to study the effects of activated water decay that can be extrapolated to fusion reactors. An irradiation system using activated cooling water as the source of energetic gamma rays is proposed at the Jožef Stefan Institute TRIGA Mark II research reactor. The conceptual designs utilizing radial piercing port for water activation is presented and analysed in the paper. At reactor full power and the maximum flow rate of 1 l/s the 16 N decay rate in the irradiation facility was calculated to be around 1.7 × 10 8 s−1 which will produce ambient dose equivalent rates up to 2 mSv/h. The proposed irradiation facility will allow shielding characterization at high gamma energies. An analysis of shielding experiment with fusion relevant materials, such as tungsten, Eurofer, SS 304L, etc., which can be implemented in the proposed water activation facility was performed. From all analysed material SS 304L and Eurofer are the best candidate materials for shielding around primary cooling water in fusion reactors to reduce additional nuclear heating to superconducting coils and other important tokamak components. From the analysis it can be concluded that around 30 cm of SS 304L or Eurofer is needed to reduce the high energy gamma ray flux by half.

中文翻译：

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JSI TRIGA 研究堆活化水辐射源辐照实验分析

摘要 核设施中的活化冷却水可以在主冷却系统周围提供重要的辐射源，从而对电气元件造成辐射损坏，增加人员受到的剂量，并且在聚变设施的情况下，超导线圈会额外加热。由于目前没有融合氘和氚的聚变反应堆能够以足够的精度进行水活化实验，裂变研究反应堆提供了一个机会来研究活化水衰变的影响，这些影响可以外推到聚变反应堆。Jožef Stefan 研究所 TRIGA Mark II 研究堆提出了一种使用活化冷却水作为高能伽马射线源的辐照系统。本文介绍并分析了利用径向穿孔口进行水活化的概念设计。在反应堆全功率和 1 l/s 的最大流速下，辐照设施中的 16 N 衰减率计算为大约 1.7 × 10 8 s-1，这将产生高达 2 mSv/h 的环境剂量当量率。拟议的辐照设施将允许在高伽马能量下进行屏蔽表征。对融合相关材料（如钨、Eurofer、SS 304L 等）的屏蔽实验进行了分析，这些材料可以在拟议的水活化设施中实施。从所有分析的材料中，SS 304L 和 Eurofer 是屏蔽聚变反应堆中初级冷却水周围的最佳候选材料，以减少对超导线圈和其他重要托卡马克组件的额外核加热。