Sources, types and quantities of radioactive waste

Radioactive wastes arise from the generation of electricity in nuclear power stations and from the use of radioactive materials in industry, medicine, research, and military. There is a wide spectrum of wastes, from those that contain high concentrations of radioactive materials, to general industry and laboratory wastes which are only lightly contaminated with activity.

The Atomic Energy Act (AEA, Article 2.18) of the Republic of Korea defines ‘radioactive waste’ as radioactive materials or materials contami­nated with radioactive materials which are subject to disposal, including spent fuel. The Enforcement Decree of the AEA defines high-level radioac­tive waste (HLW) as radioactive waste with radioactivity concentration and heat generation over the limiting volume specified by the Ministry of Edu­cation, Science, and Technology (MEST). In the strict sense, wastes other than HLW belong to the LILW category in accordance with the AEA. The limiting values on radioactivity and heat generation rate are specified in the MEST Notice No. 2008-31 (Notice of the Standards on Radiation Protec­tion, etc.) [MEST, 2008] as follows:

• radioactivity: >4,000 Bq/g for alpha-emitting radionuclides with a half­life of longer than 20 years

• heat generation rate: >2 kW/m3.

The AEA also defines the clearance level adopted from the ‘exempt waste’ concept of the IAEA radioactive waste classification. The clearance levels in Korea are such that annual individual radiation dose shall be less than 10 pSv/y and the total collective dose below one person-Sv/y concurrently. These are the same as the levels specified in the IAEA Safety Series No. 115 (1996) [IAEA, 1996].

All radioactive wastes are still to be stored in on-site temporary storage until a permanent disposal facility has been constructed. The amount of radioactive waste being stored by April 2012 is 89,865 drums from nuclear power plants (KHNP, 2012). (Hereafter, ‘drum’ means ‘200-liter drum equivalent’ unless otherwise stated.) The total capacity of temporary storage in NPP sites is 109,900 drums and the accumulated radioactive waste stored at each NPP site is around 77.7% of their storage capacity, as shown in Table 21.1 . Although the volume of waste arising from radioisotope use is still relatively small compared to power reactor waste volume, the annual gen­eration rate is expected to rise rapidly as industrial use of radioisotopes increases. The waste type and volume of LILW is shown in Fig. 21.2.

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