HC Deb 28 March 1984 vol 57 cc209-10W
Mr. Wilson

asked the Secretary of State for Defence if he will publish data to show the extent of radioactive fallout in the area of G1 monitoring station No. 7, Fitzroy Crossing, for the period 16 to 23 May 1956 after the atmospheric nuclear explosion carried out by the United Kingdom at the Monte Bello Islands.

Mr. Pattie

The radioactive fallout in the area of the monitoring station at Fitzroy Crossing resulting from the first of the two tests of the 1956 series (MOSAIC G1) on 16 May 1956 expressed in terms of millicuries per square meter (mCi/m2) of mixed fission products at one hour after detonation, was 0.74 mCi/m2. The fallout would have arrived at about 30 hours after detonation and it may be assumed to decay according to a t-1.2 law. The second test (MOSAIC G2) was not fired until 19 June 1956 and would not have added to the radioactive fallout in the period from 16 to 23 May 1956. Although the information available does not identify Fitzroy Crossing with monitoring station No. 7, the results given above refer to the station closest to Fitzroy Crossing.

A total of four sampling points were within about 100 miles of Fitzroy Crossing. The range of values at these points was from 0.2 mCi/m2 to 11 mCi/m 2.