HC Deb 03 March 1993 vol 220 c210W
Mr. Simon Hughes

To 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. McLoughlin

The 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.