Deposition of airborne radioiodine species on surfaces of metals and plastics

In this study the deposition velocity of gaseous radioiodine species I2, HOI and CH3I on several materials, which are commonly used in nuclear industry, was experimentally evaluated. Materials were identified which cause minimal deposition loss of airborne radioiodine sample in remote sampling systems. It was found that carbon steel and stainless steel, both extensively used in the construction of sampling lines, have high affinity for elemental iodine vapour. This causes significant loss of iodine sample due to wall deposition, particularly at high humidities which prevail under emergency release conditions. Aluminum, polyethylene and teflon cause minimal loss of iodine sample in remote sampling applications under both normal and emergency release conditions in nuclear power plants