The Dounreay PFR Liquid Metals Disposal Project

摘要

The UKAEA Prototype Fast Reactor (PFR) at Dounreay used liquid sodium coolant for the very high power density core. It also used sodium-potassium eutectic (NaK) in the decay heat removal system. When PFR was shut down in 1994, the reactor vessel was left holding 900tonnes of slightly contaminated sodium and a further 600tonnes of liquid sodium and NaK was stored in other vessels. The liquid metal [Note a] is being removed from the reactor and other vessels by means of specialist equipment, pre-treated and then reacted in a special vessel with a nominal aqueous solution of 10 molar sodium hydroxide. During the reaction the strength of the solution is maintained by the addition of water and sodium and the removal of an equal flow of hydroxide. After neutralisation with hydrochloric acid to produce a saline solution, the product is processed to reduce the caesium content then passed to the low level liquid effluent treatment plant for eventual discharge to the sea.