Purification of Gaseous Emissions by 14C Removal During Reprocessing of Spent Uranium-Plutonium Nuclear Fuel

Abstract

Methods for trapping the ¹⁴C in waste gases by means of a combined technology are examined. The wastes gases from pyrochemical production can be purified by removing ¹⁴C by passing the gases at rates to 5 m³/h through a 0.5 m high layer of Ba(OH)₂·8H₂O granules in a 0.14 m in diameter apparatus after dilution with atmospheric air. The purification of the waste gases from hydrometallurgical production by removal of ¹⁴C (50 m³/h) is best accomplished by passage through a 0.28 m in diameter packed tower with 2.7–4 m high packing irrigated by an alkali solution which is regenerated by means of calcium hydroxide. The waste gases from pyrochemical production can also be passed through a packed tower. In this case the ¹⁴C is fixed in insoluble calcium carbonate and is placed in a storage facility and subsequently buried. The proposed technologies make it possible to purify the waste gases formed during the reprocessing of spent uraniumplutonium nitride nuclear fuel in a reprocessing module used in an on-site nuclear fuel cycle by removing ¹⁴C to a level admissible for air in production enclosures.