報告書番号

281020

タイトル（和文）

放射性核種の地中移行挙動（その２）－放射性よう素ガスの吸着挙動の予測手法－

タイトル（英文）

RADIONUCLIDE TRANSFER IN UNDERGROUND MEDIA (2) -A PREDICTION METHOD FOR ADSORPTION BEHAVIOR OF RADIOIODINE GAS -

概要 （図表や脚注は「報告書全文」に掲載しております）

地下式原子力発電所の想定事故時の安全評価のために，花崗岩，凝灰岩，砂岩に対する放射性よう素の吸着係数について検討した。その結果，１）充填層における物質移動の理論計算から，吸着係数が破過時間を決定する要因であること，２）カラム実験による吸着量の値は吸着ポテンシャル理論によって説明できること，３）吸着整数の湿度による変化は－３．２％／℃である，４）吸着係数は湿度の影響を受け，岩粒子の表面粗さに依存する。

概要 （英文）

THIS PAPER DESCRIBES ADSORPTION COEFFICIENTS(KA)OF ELEMENTAL IODINE GAS,I-2,TO SUCH TYPICAL GROUND-FORMATION ROCKS IN JAPAN AS GRANITE,TUFF AND SANDSTONE,AND ALSO PREDICTS THE MOVEMENT OF I-2,THROUGH THE UNDERGROUND ROCKS FOR THE PURPOSE OF RISK ASSESSMENT OF RADIOIODINE RELEASED FROM THE UNDERGROUND NUCLEAR POWER STATION.CRUSHED ROCK SAMPLES WERE INVESTIGATED BY USING THE COLUMN TECHNIQUE AT VARIOUS STEPS OF TEMPERATURE AND GAS CONCENTRATION. MAIN RESULTS ARE AS FOLLOWS. 1) THE 1% BREAKTHROUGH TIME OF I-2 THROUGH 100M-LONG UNDERGROUNDCALCULATED WITH THE PACKED BED THEORY,IS PROPORTIONAL TO THE KA VALUE,AND CONSEQUENTLY THE KA IS A MAIN FACTOR FOR THE DETERMINATION OF THE BREAKTHROUGH TIME. 2) THE POLANYI S ADSORPTION THEORY IS IN GOOD AGREEMENT WITH OUR EXPERIMENTAL RESULTS AND ADSORPTION AMOUNTS PER UNIT SURFACE AREA OF THE UNDERGROUND ROCK ARE FIT TO THE POLANYI EQUATION. 3) THE KA VALUE DEPENDS ON TEMPERATURE AND VARIES AS -3.2% PER DEGREE(C). 4) HUMIDITY OF I-2 GAS AFFECTS THE KA VALUE AND THIS EFFECT CORRESPONDS TO SURFACE ROUGHNESS OF THE PARTICLE. 5) A SIMPLE EQUATION,WHICH CAN PREDICT THE KA VALUE AT A PARTICULAR TEMPERATURE AND GROUND FORMATION,IS PROPOSED ON THE BASIS OF CONSIDERING THE SIZE DISTRIBUTION. 6) THE KA VALUE OF THE GRANITE FORMATION IS ESTIMATED WITH THE ABOVE-MENTIONED EQUATION,AND THIS VALUE AGREES WITH THE VALUE PREDICTED WITH THE HYDRAULIC CONDUCTIVITY.

報告者

キーワード