§ Mr. Martyn JonesTo ask the President of the Board of Trade if he will give the quantities of plutonium material unaccounted for for each of the last 10 years of Magnox reprocessing at Sellafield, and details of projections of MUF quantities of plutonium once the thermal oxide reprocessing plant is in operation.
§ Mr. EggarSince 1977, British Nuclear Fuels plc (BNFL) and the AEA have issued annual press releases giving the difference between the book inventory of nuclear materials on each site and the measured physiical inventory. This difference, known as 'material unaccounted for'—MUF—indicates an apparent gain of material 187W when positive and an apparent loss when negative. It is not normally evidence of an actual loss or gain of material but often reflects measurement error.
The figures published by BNFL and the AEA for the 10 years to 1991–92 were:
Kg 1982–83 -0.5 1983–84 +4.2 1984–85 +9.1 1985–86 +4.0 1986–87 +2.2 1987–88 -1.5 1988–89 +4.0 1989–90 -1.0 1990–91 -11.5 1991–92 +9.8 Once the thermal oxide reprocessing plant comes into operation, its contribution to Sellafield MUF will be reflected in the site figures in the normal way. The impact on the total will depend on the plant's performance.
The safeguards system for THORP has been described in papers presented at the 15th European Safeguards Research and Development Association—ESARDA—symposium in Rome in May 1993 which make it clear that the tracking of nuclear material inventories is only part of an overall safeguards system covering a variety of arrangements.