تعیین کیفی و کمی تکنسیم-99 در پسماند تغلیظ شدۀ نیروگاه اتمی بوشهر

Technetium-99 in nuclear waste as one of the toxic and hazardous radioactive pollutants should be quantitatively and qualitatively identified before final disposal. In the present research work, Technetium -99 in the aqueous phase of the concentrated waste of Bushehr nuclear power plant was qualified and quantified. To achieve this goal, Cesium-134 and 137 were firstly separated using potassium cobalt hexacyanoferrate(II) adsorbent. Then, tritium was removed using thermal treatment at 60˚C, and finally technetium-99 in this media was purified by removing beta emitter radioisotopes such as cobalt- 60, iron-55, and nickel-63 using precipitation process with iron(III) hydroxide. The samples were qualitatively and quantitatively evaluated using gamma spectrometry and liquid scintillation counter instruments. The results showed that purified Technetium-99 has a high radiochemical purity and other radioisotopes were removed from the media with an efficiency of about 100%. Also, the beta spectrum of the sample was in complete accordance with the beta spectrum of the standard samples. The total yield of the proposed processes using the increase of Technetium-99m tracer to the original sample was equivalent to 80.69%. Taking into account the 93% efficiency of the liquid scintillation counter and the processes yield (80.69%), the specific activity of Technetium-99 was calculated as 10554.13 Bq.L^-1.