オーストリアで利用可能な木材燃料およびその灰の137Csと90Srの測定
Viktoria Herzner1, Christian Katzlberger1, Christoph Pfeifer2
1Department for Technical Radiation Protection, Austrian Agency for Health and Food Safety, Spargelfeldstraße 191, 1220 Vienna, Austria.
Radiation protection dosimetry
|August 28, 2025
まとめ
オーストリアの木炭灰は放射能の危険性が低い. 木灰に含まれるセシウム137とストロンチウム90の含有量は,健康に重大な危険をもたらさないため,輸入制限は必要ないことを示している.
科学分野:
- 環境科学
- 放射線医学
- 核化学
背景:
- 木材燃料はオーストリアで広く使用されていますが,特に灰からの放射能の影響は完全に理解されていません.
- 商業的に調達された木材燃料は起源が不明であり,放射性プロファイルが異なる輸入材料を含む可能性があります.
- 木灰に伴う放射線リスクの評価は,公衆衛生と環境安全にとって極めて重要です.
研究 の 目的:
- オーストリアにおける木材燃料とその灰による放射線リスクの評価
- 主要な放射性核素であるセシウム137 (137Cs) とストロンチウム90 (90Sr) の活性濃度を,様々な木材燃料およびその生成した灰で定量化する.
- 放射線安全性に基づく輸入規制が必要かどうかを判断する.
主な方法:
- 69個の木材燃料サンプル (チップ,ログ,ペレット,ブリケット) と27個の灰サンプルを採取して分析した.
- 高純度ゲルマニウム検出器を用いたガンマ線スペクトロメトリを用いて137Csの活性濃度を測定した.
- 化学分離後の液体シンチレーション計数による12個の灰の活性濃度の定量化.
主要な成果:
- 木材燃料における137Csの活性度は平均で2.1 Bq kg-1 (範囲は0.3278.36 Bq kg-1) であった.
- 灰中の137Csの活性度は平均で310 Bq kg-1 (範囲は11.80867 Bq kg-1) であった.
- 灰中の90Srの活性度は平均655Bqkg-1 (範囲は363~1200Bqkg-1) であった.
結論:
- 木材燃料と灰における137Csと90Srの測定された活性濃度は,放射能の重大なリスクとみなされるレベルを下回っている.
- 現在,オーストリアで利用されている木材燃料は,灰を通して放射能の危険性を有しません.
- 放射線安全に関する懸念に基づく木材燃料の輸入規制の必要性を裏付ける証拠はない.
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