Radiation damage to 30 vol.% TBP (Tributyl phosphate)/Kerosene solvent was investigated on the behavior changes of fission products and nitric acid in extraction and in stripping with 0.01 N nitric acid at 25°C.
In these extraction-stripping experiments, three types of solvent were used; namely, ⁶⁰Co γ-ray irradiated (10⁴-10⁸r) solvent, non-irradiated solvent and synthetic “damaged solvent”, or DBP (Dibutyl phosphate)-MBP (Monobutyl phosphate), Butanol or Pyrophosphoric acid added TBP/Kerosene.
It has been revealed in beaker scale experiments that ⁹⁵Zr-⁹⁵Nb is extremely effected in extraction-stripping with radiation damaged and synthetic damaged solvent comparing with ¹⁰⁶Ru-¹⁰⁶Rh, ¹³¹l, ¹⁴⁴Ce_¹⁴⁴Pr and gross fission products, and that its behavior change depends mainly on the formation of DBP-MBP, but not on that of Butanol or Pyrophosphate.
¹⁰⁶Ru-¹⁰⁶Rh is hardly effected in extraction with damaged solvent and is effected only in stripping from damaged solvent.
Neither ¹⁴⁴Ce-¹⁴⁴Pr nor nitric acid is influenced by radiation damage to the solvent.
¹³¹l behavior change is different from others.
Emulsion formation was observed only in ⁹⁵Zr-⁹⁵Nb extraction with 10⁷r or more irradiated and DBP-MBP added solvent (0.1g or more/l-solvent).
Settling time or phase separation time changes may not affect the process significantly except in the case of emulsion formation.

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The fluid flow resistance through the round tube in boiling is different from the two-phase flow, but it is not very identified.
It has been definitely shown that as the result of semi theoretical analysis and experiments in net boiling of forced flow in 20∅ tube at 3 to 13m/sec, 2 to 150 ata and in 14×10⁵kcal/m²hr, the turbulency of flow by turbulent energy based upon the detach from the tube wall and growth of the bubbles is generated, and the fluid flow resistance is also changed. But this turbulency is not larger than the turbulency of normal flow in tube except cases of low flow velocity or low pressure, and that effect is neglisible in practice. Then the coefficient of frictional flow resistance through the round rough tube in normal turbulent flow is available to in heigh velocity flow at heigh pressure in net boiling too.

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The excitation functions for the reactions ⁴⁸Ti (α, n) ⁵¹Cr and ⁵¹V (α, n) ⁵⁴Mn up to E_α=31 MeV have been measured by the activation method using a stacked-foil technique. The cross sections at maximum yield in the (α, n) reactions for ⁴⁸Ti and ⁵¹V are (6.8_-2.0^+1.4)×10^-25cm² and (5.6±1.1)×10^-25cm², respectively. The (α, n) reaction for ⁵¹V is economically attractive for the production of carrier-free ⁵⁴Mn.

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The results in the öre processing and metal production tests carried out over one year at pilot plants of Tokai Refinery, Atomic Fuel Corporation, Tokaimura, Ibaraki Pref. are givén and the prospect to commercial plants, of 100t. ore/day and 100t. U/year each, is presented in terms of material balance diagrams with few reasonable assumptions based on test results.
On the ore processing, a prospect on domestic ore reserve and its grade as well is disclosed, the adaptability of domestic ore to milling is analysed, and then ore characteristics in processing is given summarizing from the test results on acid leaching, solid-liquid separation and solvent extraction-stripping. The mill cost is studied from the view point of economical feasibility to enterprising, illustrating the relation between allowable cost of ore as well as product price on one hand and mining cost on the other.
On the metal production, the superiority of the new refining process, “Excer” process, to the conventional one is demonstrated based on test results and the mechanism and operation of equipment such as Higgins column for ion exchange, ionic cell for electrolysis are reported in detail.
Reduction step from wet-processed UF₄ to metal is reported so as to introduce for the first time the practice into plant scale operation. Low tap density inherent to wet-processed UF₄ showed no unfavorable effect on the reduction at all. Studies on briquette reduction, amine extraction and scrap recovery are also briefed. They will in due course be useful to improve the operation very much.

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