Mr. Crimondasked the Secretary of State for Energy if he will investigate the apparent discrepancy between the stocks of plutonium held by the United Kingdom Atomic Energy Authority and the amount shown in its accounts; and if he will make a statement.
§ Mr. EadieThe differences between the physical inventory and the book inventory of nuclear materials known as Material Unaccounted For (MUF) are essentially due to uncertainties in the estimation or measurement of the individual items in the "balance sheet". The United Kingdom Atomic Energy Authority and British Nuclear Fuels Ltd. are developing a variety of measurement and assessment techniques which, with improved design of plant and operation procedures to aid more accurate measurement, can be expected to reduce uncertainties in the future. Assessments of MUF are not the primary checks that material has not been lost, stolen or inadvertently discharged to the environment. The safekeeping of nuclear material, the safe and secure operation of the plant concerned and the observance of authorised limits of the dis- charge of radioactive effluent are all ensured by a number of separate procedures applied to individual plants, sources of effluent and areas within the sites.
I am advised that none of the figures of MUF nor the uncertainties in them 561W need give concern over either safety or security at nuclear installations.