Jackson D, Zimmerman C H, Gray J
Westlakes Scientific Consulting Limited, Cumbria, UK.
J Radiol Prot. 1998 Jun;18(2):111-8. doi: 10.1088/0952-4746/18/2/006.
The radionulide 85Kr, which has a half-life of 10.72 years, is produced, almost exclusively, by reprocessing operations during which the fission product is released from irradiated nuclear fuel by chemical dissolution. Reprocessing plants at Sellafield, in Cumbria, have released the noble gas to atmosphere since operations commenced in 1952. Historically, krypton discharges were classified for security reasons, although these have been monitored and published by BNFL for each year since 1977. This paper reviews discharges of 85Kr from Sellafield, and consequent radiation doses, since its earliest operations. Over the past three years, discharges of 85Kr have increased due to the operation of the Thermal Oxide Fuel Reprocessing Plant (Thorp). Nonetheless, the associated annual committed effective dose to individuals remains low, peaking around 1.5 microSv a-1 to the identified critical groups, which compares with typical annual committed effective doses from natural sources of radiation of 2200 microSv. Maximum collective doses predicted from any single year of operations are 0.6 man Sv, 2 man Sv and 42 man Sv to the UK, Europe and the world respectively. Comparison may be made to natural background committed effective doses, which are of the order of 130,000 man Sva-1, 750,000 man Sva-1 and 13,000,000 man Sva-1 to the UK, EU and world populations respectively.
放射性核素氪-85的半衰期为10.72年，几乎完全是在后处理操作过程中产生的，在后处理过程中，裂变产物通过化学溶解从辐照核燃料中释放出来。自1952年运营开始以来，位于坎布里亚郡塞拉菲尔德的后处理厂就一直将这种惰性气体排放到大气中。从历史上看，出于安全原因，氪的排放量被列为机密，尽管自1977年以来英国核燃料公司（BNFL）每年都对其进行监测并公布相关数据。本文回顾了塞拉菲尔德从最早运营以来氪-85的排放情况以及由此产生的辐射剂量。在过去三年中，由于热氧化物燃料后处理厂（Thorp）的运行，氪-85的排放量有所增加。尽管如此，相关的个人年约定有效剂量仍然很低，确定的关键人群的年约定有效剂量峰值约为1.5微希沃特/年，而天然辐射源的典型年约定有效剂量为2200微希沃特。任何一年运营预测的最大集体剂量分别为：英国0.6人希沃特、欧洲2人希沃特、全球42人希沃特。与之相比，天然本底约定有效剂量分别约为：英国人口130000人希沃特/年、欧盟人口750000人希沃特/年、世界人口13000000人希沃特/年。
