Suppression methods of radon emanation from phosphorus fertiliser and diatomaceous earth

• Published in: Radiation protection dosimetry Vol. 124; no. 2; pp. 75 - 84
• Main Authors: Sasaki, T., Gunji, Y., Okuda, T.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-04-2007
• Subjects: Desiccation - methods; Diatomaceous Earth - chemistry; Fertilizers; Hot Temperature; Phosphorus Compounds - chemistry; Radiation Dosage; Radiation Protection - methods; Radiometry; Radium - chemistry; Radon - chemistry; Radon - isolation & purification; Sulfur - chemistry
• ISSN: 0144-8420; 1742-3406
• DOI: 10.1093/rpd/ncm420

The present paper shows methods to suppress radon emanation from artificial porous materials such as phosphorous fertiliser or diatomaceous earth with a small amount of radium. The basic concept of suppression is making the radon emanation mechanism ‘null’, which comes from the fact that recoil is the main mechanism of radon emanation at room temperature. Nullifying may be done through removal of water in the pore volume by heating and through removal of pores by melting or filling with sulphur. These radon emanation suppression methods were tried for phosphorous fertiliser and diatomaceous earth with a small amount of radium. The melting method was the most effective of all. Sustainability of these methods was also studied. The melting method was the most sustainable. The heating method was also sustainable for diatomaceous earth in spite of a long-term immersion in water.