Developments of gaseous water, hydrogen and methane sampling system for environmental tritium monitoring
Developments of gaseous water, hydrogen and methane sampling system for environmental tritium monitoring
复制标题
环境氚监测气态水、氢气、甲烷采样系统的研制
DOI：
10.1016/j.fusengdes.2005.08.077
复制
发表时间：
2006
影响因子：
1.7
通讯作者：
N. Momoshima
中科院分区：
文献类型：
--
作者：
T. Uda;T. Sugiyama;Masahiro Tanaka;K. Munakata;N. Momoshima
从环境安全的角度来看，必须测量核聚变设施内或周围大气中的氚浓度。大气中氚的主要化学形式是水、氢和甲烷。我们提出了一个自动顺序的过程来测量这些化学形式，允许可靠的操作和节省大量的劳动时间。水蒸气在分子筛中很容易收集。氢气或甲烷的取样方法是使用催化剂将气体氧化成水，然后在分子筛中吸收水。对于氢氧化，使用Al-Cr-Fe金属蜂窝的Pt催化剂，因为它具有较小的压降和对氚污染的记忆效应。对于甲烷氧化，使用传统的钯氧化铝催化剂。在对大气中的氚取样一周后，从分子筛中回收水。用低本底液体闪烁计数器测量回收水中的氚浓度。自动采样系统测得的大气氚浓度与人工采样系统测得的数据一致。
The atmospheric tritium concentration in or around a nuclear fusion facility must be measured, from the environmental safety point of view. The major chemical forms of atmospheric tritium are water, hydrogen and methane. We present an automatic sequential process for measuring each of these chemical forms, allowing reliable operation and saving much labor time. Water vapor is collected easily in a molecular sieve. The sampling method for hydrogen or methane is to oxidize the gas into water using a catalyst and to absorb the water in a molecular sieve. For hydrogen oxidization a Pt catalyst with an Al–Cr–Fe metal honeycomb is used because it is expected to have a small pressure drop and little memory effect from tritium contamination. For methane oxidization, a conventional Pd alumina catalyst is used. After sampling atmospheric tritium for a week, the water is recovered from the molecular sieves. The tritium concentration in the recovered water is measured with a low background liquid scintillation counter. The atmospheric tritium concentrations obtained by the automatic sampling system are consistent with the data of a manual sampling system.