Following is a question by the Hon Henry Wu and and a written reply by the Secretary for Health and Welfare, Dr E K Yeoh, in the Legislative Council today (February 28):
It has been reported that a man was found in a wartime air-raid shelter used for storing radioactive waste on the 19th of last month. In this connection, will the Government inform this Council:
(a) whether the man was contaminated by radio-activity as a result;
(b) of the locations and current usage of the existing wartime air-raid shelters;
(c) of the present number of air-raid shelters used for storing radioactive waste, and whether regular tests are conducted to determine the ambient radiation level in these air-raid shelters; if so, the frequency of such tests and the date and findings of the last tests;
(d) whether it will consider installing devices so that the department concerned will be immediately alerted to any unauthorized entry to an air-raid shelter used for storing radioactive waste; and
(e) of the measures in place to prevent persons who have entered such air-raid shelters from being contaminated by radio-activity?
(a) The person concerned was examined at the scene by health physicists of the Department of Health (DH). No detectable radioactivity was found on his body and clothing.
(b) There are currently 82 disused tunnel networks known to the Civil Engineering Department. Of these, 29 were purposely constructed as air-raid precaution tunnels, and the remainders were constructed for a variety of purposes. The number of disused tunnel networks located at Hong Kong Island, Kowloon, and the New Territories & Islands are 54, 18 and 10 respectively.
Three tunnel networks are currently being used by the Government, namely:
(i) one network in Queen's Road East used for storage of low-level radioactive wastes;
(ii) one network at Shouson Hill used for storage of soil and rock samples; and
(iii) one network at Lei Yue Mun used as part of the Hong Kong Museum of Coastal Defense.
(c) Only a small section of the Queen's Road East tunnel network has been used for storing low-level radioactive wastes. DH carries out monthly monitoring of ambient radiation outside the network and monitoring of the cumulative radiation dose inside the network. The radiation levels outside the network have been consistently found to be the same as the normal natural background levels. In the section of the network where there are waste materials in store, the general radiation level satisfies the principles of occupational safety and protection set by the International Commission on Radiological Protection.
(d) To prevent a recurrence of unauthorized entry into the tunnel network in Queen's Road East where radioactive wastes are being stored, the locking devices on the steel doors have been immediately strengthened after the incident. We will consider devising further measures to prevent unauthorized entry.
(e) The low-level radioactive wastes stored in the Queen's Road East tunnel network, all in solid form, are sealed in stainless steel double-layer drums which are reinforced with a sealant in between the layers. This form of high-standard containment will effectively prevent the wastes from leaking out even during transportation. Persons entering the tunnel network will not be contaminated by radioactivity.
End/Wednesday, February 28, 2001