In Japan, the radioactivity concentrations of low-level radioactive wastes (LLW), to be disposed of at the Rokkasho Low-Level Radioactive Waste Disposal Center (Rokkasho Disposal Center), are determined by the scaling factor (SF) method.
As it has been applied SF are calculated by a conservative method according to the type of waste. Based on about ten years’ experience and research in waste disposal, rationalization of the radioactivity evaluation method was studied from the following standpoints:
i) Rationalization of the SF method using Cs-137 as a key nuclide;
ii) Rationalization of the SF calculation method.