Studies on the Impact of Various Physical Forms Iodine on Source Term and Radiological Impact Assessment During Severe Accident Conditions for VVER-1000
A. Biswangri, P. Krishna Kumar, Y.K. Pandey, H.P. Rammohan (Nuclear Power Corporation of India, Ltd)
During Severe Accident conditions, studies on the Radioactive Iodine isotopes are crucial as it helps in assessing the Radiological impact and the counter measures that would be required to mitigate the consequences. The impact of the radioactive isotope depends on the amount of Iodine source term and its physical and chemical forms. Severe Accidents involving iodine release to the environment has been studied and evaluated for VVER-1000. Typically,Iodine isotopes are classified into three physical forms a) Molecular b) Aerosol and c) Organic and each have their different behavior in the containment. The objective of the article is to bring out the impact of these physical forms of iodine, which have different type of interactions with the containment surface, different type of diffusion through the containment wall and have different filter efficiencies. The combined effect of these parameters were studied for the Radiological Impact Assessment (RIA) of the iodine source term.
VVER-1000のシビアアクシデント状態におけるソースタームおよび放射線影響評価に対するさまざまな物理的形態のヨウ素の影響に関する研究
A. Biswangri, P Krishna Kumar, Y.K.Pandey, H.P. Rammohan (Nuclear Power Corporation of India, Ltd)
我々はいかにしたらカナダで復旧段階の科学を先験的に開発できるのかを実証し、降下物事象の時間的経過を予測するために使用できるパラメータとモデルを提示するために、オタワ川上流域（59,246 km2）での兵器実験降下物を用いる。Cs-137の質量収支は過去のデータに加えて、水、堆積物、土壌、針葉樹、落葉樹及び下層植物のサンプルから組み立てられた。現在、兵器実験のCs-137降下物の95%がオタワ川上流域に残っており、流出によって失われたのは5%のみで、80%が土壌の最上層15 cmに存在している。土壌中のCs-137のインベントリは流域全体で極めて類似しており（937 ± 66 Bq m-2）、土壌の種類やKdの間に有意な差は見られない。しかし、土壌から植物への移行には数桁の差があり、氷河湖成粘土に由来する土壌からの移行率は非常に低く、粘土がほとんど含まれない土壌からの移行率ははるかに高い。
