With its long half-life (5730 years) and high mobility in the environment, C-14 is a radionuclide of considerable interest in nuclear power production. Carbon-14 is present in virtually all parts of nuclear reactor primary system and has a high production rate. It is released to the environment through gaseous and liquid discharges and though the disposal of solid radioactive waste. This paper summarizes existing scientific understanding of C-14 issues surrounding nuclear power production. Two main purposes of the paper are: (1) To provide the basic/up-to-date understanding of the life cycle of C-14, starting from its production in reactors, to eventually its transport and its potential incorporation in natural cycles; (2) To present the technical issues in current C-14 waste management. The emphasis of the paper is on Light Water Reactors (LWRs, which include Pressured Water Reactors-PWRs, and Boiling Water Reactors-BWRs) and Heavy Water Reactors (HWRs-CANDU type reactors). Major issues with C-14 in HTGR are also addressed. (C) 2005 Elsevier Ltd. All rights reserved.