In the event of an emergency, action would be taken to prevent emergency reference levels (ERL) of ra­diation dose being exceeded. However, experience at Three Mile Island showed that the public would no longer be satisfied with the information that they had not been exposed to a ‘significant level of radiation’. It was therefore decided that, for the recovery of public confidence following an incident, the CEGB should provide the best estimates of individual ef­fective dose equivalent and collective effective dose equivalent at all stages of an emergency and at levels well below the ERL. The following procedures have been adopted to make the necessary population dose assessment:

• The minimum level of individual effective dose equivalent that would be assessed is 0.5 mSv, i. e., one-tenth of the annua! dose limit for members of the public. [41] power station. The readings of these monitors are telemetered to the site emergency control centre and would provide a time profile of any release of airborne radioactivity. This information would assist in the interpolation and extrapolation of the inhalation and deposition measurements made by the off-site survey teams.

• An emergency dose assessment service has been established at Berkeley Nuclear Laboratories. This team of specialists would make an assessment of the effective dose equivalent from data supplied from the OSC by telephone teleprinter and facsimile transmission.