§ Mr. Simon HughesTo ask the Secretary of State for Employment what quality factors are normally used by health physics staff at nuclear installations; what alterations were made in them during the recent radioactive leak at Sellafield; and for what reason.
§ Mr. McLoughlinThe quality factors normally used by health physics staff at nuclear installations for radiological protection purposes are:
Factor For 'x' rays, gamma rays and beta particles QF = 1 For 'thermal' neutrons QF = 2.3 For 'fast' neutrons QF = 10 For alpha particles, multiple charged particles QF = 20 Since different types of radiation have different biological effects, absorbed doses have to be multiplied by a "quality factor" before they can be expressed on a common "dose" scale for radiation protection purposes —that is, put in terms of the "dose equivalent". No alterations were made to them in assessing the potential dose of radiation to a member of the public during the recent releases of radioactivity from the B204 and B6 stacks at Sellafield.