§ Mr. Lubbock
asked the Minister of Technology (1) what is his present estimate of the annual dose equivalent to crew members of the Concorde from galactic radiation on North Atlantic 7W routes; and if he will state the number of flying hours and the number of hours at cruising altitude to which this estimate relates;
(2) what steps will be taken to monitor exposure of crews of the Concorde to galactic and solar radiation, respectively;
(3) what research he is conducting to determine the radiation dose equivalent of occupants of the Concorde in polar latitudes per unit of time at cruising altitude, with particular reference to the biological effects of energetic heavy nuclei on cells and tissues, and the relative biological effectiveness of high energy radiations at low dose rates;
(4) what research he is conducting to determine the radiation dose equivalent of occupants of the Concorde in polar latitudes per unit of time at cruising altitude, with particular reference to the development of practical methods to enable the early detection and avoidance of solar flare radiation, and the variations in quantity and quality of cosmic radiations, including primary heavy nuclei, with altitude, latitude, solar activity and shielding.
§ Mr. Benn
The estimated average annual exposure of a Concorde crew member on North Atlantic routes, based upon 700 flying hours a year, 560 of them at over 50,000 feet, is 0.65rems; this is equivalent to the dose from between 6 and 7 typical medical X-ray examinations. Concorde will carry an exposure montitoring device which will also give warning of the onset of exceptional solar flare radiation; this will then be avoided by the aircraft descending to a lower altitude.
Research conducted into radiation levels at different latitudes has shown that, although radiation at Concorde cruising altitudes roughly doubles between the equator and the magnetic poles, there is little significant difference between levels on the North Atlantic and Polar routes. There is little variation in the proportion of heavy nuclei in galactic radiation, and whilst less is known about the composition of solar flare radiation the proportion of heavy nuclei is usually small. No research is being conducted by the Ministry of Technology specifically into the composition of solar flare radiation or the biological effects of heavy nuclei, but these factors have been 8W allowed for in calculating the amount of radiation to which Concorde passengers and crew may be exposed and substantial safety margins included where appropriate. In view of the very low level of this radiation, no special shielding will be necessary.