Non-primordial technetium

The activity of the precipitate was counted with a low-background /T-countcr, with a background of about 0.7 counts per min. The observed activity measured in the precipitate per kg ore was 1.8, 1.7 and 2.1 counts per min for the three pitchblende samples, respectively. The average half-thickness value of 7 1 mg/cra aluminum was in agreement with the accepted half-thickness value of 7.2 mg/cm Al for Tc. The atomic ratio Tc/ U in pitchblende was found to be fairly conformable with the 

Some billion years ago natural nuclear reactors must have operated and generated Tc as a high yield fission product by induced fission of with slow neutrons. The relics of a natural reactor were discovered in 1972 at the Oklo uranium mines in the Republic of Gabon, Africa. lire Oklo phenomenon occurred 1.72 billion years ago and produced a greater amount of Tc than detected in other uranium ores [20. Ruf-fenach et al. [21] reported values of integrated flux of thermal neutrons for the Oklo uranium ores of up to 1. . 2 10 n cm and a atomic ratio down to 0.00410, 

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