In another method , called the van Arkel-de Boer process , the oxide was chemically converted to a halide ( chloride , bromide or iodide ) and then reduced in a vacuum with an electrically heated metallic filament : 2 PaI5 → 2 Pa + 5 I2 In 1961 , the United Kingdom Atomic Energy Authority ( UKAEA ) produced 125 grams of 99.9 % pure protactinium by processing 60 tonnes of waste material in a 12-stage process , at a cost of about 500,000 USD .
In 1961 , the United Kingdom Atomic Energy Authority was able to produce 125 g of 99.9 % pure protactinium , processing 60 tons of waste material in a 12-stage process and spending 500,000 USD .