四川省粉煤灰中天然放射性含量及安全性评价

对四川省（ 含重庆）８ 个大、中型火力发电厂排出的干／湿粉煤灰中天然放射性核素的组成和含量进行了测定和分析；并调查了我省粉煤灰的综合利用情况。结果表明，四川省火力发电厂排出的粉煤灰中天然放射性核素主要由２３８Ｕ，２３２Ｔｈ，２２６Ｒａ，４０Ｋ４ 种核素组成，放射性比活度变化在０～１０９７９ ±１６６９（２３８Ｕ），８２０５ ±２７８ ～２２４４７ ±１１７３（２３２Ｔｈ），６３９２ ±２７５ ～２５５８ ±３８６（２２６Ｒａ），１１７７２±１４７７ ～１１４７４３±３４５１（４０Ｋ）Ｂｑ／ｋｇ 。根据国家标准ＧＢ６５６６ － ８６，四川省火力发电厂粉煤灰用做建筑材料时，以江油（ 湿灰） 、内江、攀枝花、宜宾和雅安（ 湿灰） 调查点的灰样放射性比活度不超标，其余调查点的灰样均属超标范围，根据ＧＢ６７６３－ ８６ 中限制式计算，其最高用量不能超过建筑材料总重的６８６７ ％ ～６９５８ ％ （干灰） 和６８６９ ％ ～９１４０％ （ 湿灰） 。干粉煤灰的比放射性活度普遍高于湿灰。粉煤灰在农业上的利用具有潜在的优势，本文就此进行了较为详细的分析

Detection and Assessment on the Safety for Natural Radioactivity of Fly Ash of the Coal-Fired Power Plants in Sichuan Province

Composition and radioactivity of natural radioactive nuclides of dry and wet fly ash in eight coal fired powder plants in Sichuan province and Chong Qing city were detected, meanwhile the related synthetic utilization situations were investigated. The results show that the natural radioactivity of the fly ash of the coal fired powder plants in Sichuan province and Chong Qing are chiefly composed of four nuclides 238 U, 232 Th, 226 Ra, 40 K and their radioactivity ranges 0～109 79±16 69( 238 U), 82 05±2 78～224 47±11 73( 232 Th), 63 92±2 75～255 8±3 86( 226 Ra), 117 72±14 77～1147 43±34 51( 40 K) (Bq/kg), respectively. According to the standard of the People's republic of China GB 6566-86, the radioactivity of the dry and wet fly ash used as building materials in Jiang You (wet), Nei Jiang, Pan Zhihua, Yi Bing and Ya'an (wet) do not exceed the limited safe scales, but one of the other investigated areas does, whose highest useful percent of total weight of building material couldn't exceed 68 67%～69 58% (dry) and 68 69%～91 40% (wet) based on the other standard of the People's republic of China GB 6763-86. The potential advantage of fly ash applied for agriculture is discussed carefully in this paper.