AN EXPERIMENTAL STUDY OF THE RECOVERY OF PLUTONIUM FROM NON-COMBUSTIBLE WASTES
Removal of loose PuO-2 from non-combustible plutonium contaminated waste by Arklone (1,12-trichloro,1,2,2-trifluoro-ethane) has been demonstrated on a laboratory scale. While aqueous containing media are generally more effective decontaminants, Arklone has the advantages of being non-moderating and easily recycled by distillation. Although low pressure spraying and vibrocleaning are effective contacting methods, ultrasonics gave the highest DFs, reducing residual Pu levels to 1-10 mug/cm**2. Lower levels are unattainable in a simple batch process due to redeposition of particulates in small surface flaws. More aggressive processes are needed to achieve further decontamination, such as paint stripping from mild steel followed by treatment with Marshall's solution (<10**4 muCi/cm**2), or electrochemical decontamination for stainless steel (<10**-5muCi/cm**2). Microscopic smoothness has been identified as the most significant parameter in determining PuO-2 retention and subsequent ease of decontamination. To maintain this, radiation resistance is important as also is surface hardness under abrasive conditions. For facility walls and ceilings, therefore, electropolished stainless steel, 316L or PEEK foil faced GRP, and epoxy paint (treated with fine TiO-2, to block any surface defects) are recommended to reduce residual PuO-2 to <1mug/cm**2 after ultrasonic washing, while work hardened polish rolled stainless steel and bright nickel or chrome electroplates are suggested to achieve similar levels on the floor.
Bibliographic Reference: EUR 10491 EN (1986) FS, 115 P., BFR 400, EUROFFICE, LUXEMBOURG, POB 1003
Availability: Can be ordered online
Record Number: 1989124110400 / Last updated on: 1987-01-01
Available languages: en