[en] A radiochemical method has been developed for the determination of ⁹⁹Tc in low-level radioactive waste from nuclear facilities, using ^99mTc as an internal tracer. Radioactive contaminants were removed by carrier hydroxide precipitation and chelating extraction with NaDDC/CHCl₃ system at pH 4. The final technetium was chelated with NaDDC in 3N HCl solution and extracted selectively into chloroform. The average of radiochemical recovery for various types of LLW sample is about 90%. The decontamination factors for most radioactive nuclides are higher than 10⁵. The detection limit for ⁹⁹Tc in a sample of about 10 g is 0.17 pCi/g (6.5Bq·kg^-1) for a 100-minute count. (author) 34 refs.; 2 figs.; 10 tabs