Performance of wood and wooden materials as radon sealant

本文从房屋的建造方法和使用材料等方面对室内氡浓度进行了调查，结果表明，木结构房屋的氡浓度低于钢筋混凝土房屋。某些RC建筑在高空气压缩和空调条件下显示出极高的浓度，超过100 Bq/m^3。考虑到日本未来的住宅状况，RC住宅将成为住宅的常见形式，完全空调将广泛普及。值得注意的是，氡浓度高的钢筋混凝土房屋数量增加。但在施工中不可避免地要使用无机材料。在这种情况下，防止无机材料的氡析出被认为是重要的。本研究是为了了解木材作为日本未来住宅室内氡密封材料的能力而进行的。实验结果表明，厚度小于1 mm的薄木材材料可以防止30-40%的无机材料的氡析出。即使在气体扩散条件下，薄板也能阻止90%以上的氡扩散。我们发现，改进木制材料将有可能提供一种良好的内部材料，防止氡从无机材料中散发出来。

Circumstances of indoor randon concentration were investigated in connection with the method of building construction and used materials in houses.The results revealed that the radon concentration in wooden houses showed lower than that of RC-houses. Some RC-buildings showed extremely high concentration, over 100 Bq/m^3, in cases of high air tightened and air conditioned conditions.Considering Japanese housing situation in the future it would be obvious that RC-house would become common for dwelling and the complete air condition would be widely spread. Then it should be noticed that RC-houses which have high radon concentration increase in the number. But it would be impossible to avoid to use inorganic materials in the construction. At the cases it is considered to be important to prevent radon emanation from inorganic materials.This investigation was carried out to know the ability of wood as radon sealant indoor materials for future housing of Japan.The experimental results showed that thin wooden materials less than 1 mm in the thickness prevent 30-40% radon emanation from inorganic materials. Even in the case of gas diffusion condition the thin boards prevent over 90% of radon diffusion.We found that improvement of wooden materials would make possible to provide a good interior materials which prevented radon emanation from inorganic materials.