高能X射线整车原木辐照检疫中的感生放射性

Induced radioactivity by high-energy X-ray irradiation of quarantine vehicle logs

利用加速器产生的高能电子束或者高能X射线进行原木辐照处理过程中,原木和车厢有可能会产生感生放射性,从而可能会对工作人员或后续的消费者带来不必要的辐射照射风险。采用MonteCarlo方法,使用FLUKA程序结合解析经验公式,以25MeV和35MeV高能X射线装置为例,建立了高能X射线整车原木辐照检疫中的感生放射性计算模型,并比较了16、20、25、35MeV的辐照装置可能产生的感生放射性核素的剂量率。结果表明:由于木材的感生放射性核素多为短寿命核素,故不需要考虑原木被辐照后的感生放射性的影响;但只有16MeV辐照装置能够满足工作人员每年20mSv的剂量限值要求,因此需要对车厢经过辐照后对工作人员的长期辐照进行防护。

The use of high-energy electron beams or X-rays produced by high-energy accelerators to inspect logs and trailers causes those items to become radioactive resulting in unnecessary radiation exposure to the staff and even to consumers. A Monte Carlo law analysis was used to evaluate the effects of 25 MeV and 35 MeV high-energy X-rays on a log irradiation quarantine system based on the FLUKA program and empirical formulas. Comparison of the dose rates from activated radionuclides produced by 16 MeV, 20 MeV, 25 MeV and 35 MeV radiation beams shows that the induced radiation effects do not have to be considered since the activated radionuclides in logs are all short-lived. However, workers experiencing long-term exposure to the irradiated trailers need to be protected, since only the 16 MeV irradiation meets the 20 mSv per year dose limit for workers.