monitoring programme and in considering action to reduce doses to the public by implementing countermeasures. It is therefore convenient to divide the period of the emergency response into the three time phases as described in Section 5.7.
The early phase, where the immediate risk from the airborne release may be due to:
(i)
the inhalation of radioactive material;
(ii)
irradiation from the radioactive plume.
The intermediate phase, where the risk may be due to:
(i) external radiation dose from ground deposition;
(ii) internal radiation from inhalation of resuspended particulate radioactivity; (iii) internal radiation from ingestion of contaminated fresh food and water.
The recovery phase, where the risk may be due to:
contaminated foodstuffs;
(i)
(ii)
ground contamination.
8.3 The Emergency Monitoring Programme
Co-ordination of the Programme and Units
The emergency monitoring programme will in some circumstances involve many different Government Departments, agencies, academic institutions, etc. It is essential that a single body should co-ordinate the whole programme; the Royal Observatory should be tasked with this role.
It is important that all measurements should be recorded using a consistent system of units. This should be the Systeme Internationale d'Unites, (SI).
Emergency Alerting
In the event of an accidental release of radioactivity from the Daya Bay nuclear power station, it would be a matter of
urgency to initiate the programme of environmental monitoring and sampling so that, if necessary, early action could be taken to implement countermeasures. Arrangements will be made with the operators of the Daya Bay nuclear power station to notify the Hong Kong Authorities (initially the Royal Observatory) immediately of any incident which could give rise to a major release (see Chapter 5). However, since it is possible that in an accident situation it may be difficult in the initial stages for the operators to assess the level of a release and communicate this information accurately, reassurance can be provided by the use of fixed monitoring stations in the north-eastern area of Hong Kong.
The Early Phase of an Emergency
The primary objective during the early phase will be to provide information on which a timely decision can be made on the need for sheltering the public in any area, or to provide reassurance to the public that sheltering is
not necessary.
In the early phase of an accident, the emergency monitoring teams would require a capability to measure:
(i)
radiation dose rates from the radioactive plume,
50