宝鸡燃煤电厂原煤及粉煤灰中天然放射性水平

NATURAL RADIOACTIVITY LEVEL IN COAL AND ASH COLLECTED FROM BAOJI COAL-FIRED POWER PLANT

本文调查测量了宝鸡电厂原煤(3个样品)、粉煤灰(17个样品)、底灰(6个样品)中天然放射性核素226Ra、232Th和40K的比活度,分析了燃煤产生的底灰和粉煤灰中上述核素的含量特征,及其与原煤相比的浓集倍数。宝鸡电厂原煤和粉煤灰样品中天然放射性核素226Ra、232Th和40K的比活度水平与北京电厂和上海电厂的接近。依据国家标准(GB 6566-2001),对宝鸡电厂粉煤灰用作建筑材料的可行程度进行了评价,得出当建材原料100%为粉煤灰时,约有29%的样品超过国家标准的限制值。所以,应对用作建材原料的粉煤灰作放射性检测,选用合格的部分,控制高比活度粉煤灰在建材原料中的配比,以确保达到合理使用的效果。

Specific activities of natural radionuclides ^226Ra, ^232Th and ^40K were assessed in coal （3 samples）, fly ash （17 samples）and bottom ash （6 samples） collected from Baoji coal-fired power plant. This paper analyzed the characteristics of ^236Ra, ^232Th and ^40K contents in bottom ash and fly ash, and studied the concentration factors of these radionuclides in ash in relation to those in coal. The level of natural radionuclides ^226Ra, ^232Th and ^40K of coal collected from Baoji coal-fired power plant are in the range of radionuclides contents of Chinese coal. The natural radioactivity level of fly ash collected from Baoji coal-fired power plant is close to Beijing and Shanghai coal-fired power plants. The paper farther assessed the possibility of fly ash of Baoji coal-fired power plant used as building materials according to the state standard. The results show that there are 29% samples exceeding the state limit when fly ash used as building materials. So the usage of fly ash in building material should be controlled.