CBRN event in India on Sat 7th April 2012

On April 07, 2010, AERB received a report from a hospital in New Delhi about a patient, a scrap metal dealer with suspected radiation-induced symptoms. It was also informed that the patient is a scrap metal dealer and has a shop in Mayapuri New Delhi. Two AERB officers were promptly sent to the site who confirmed the presence of radioactive material in the scrap shop of the dealer. Their survey also indicated presence of radioactive material in two other shops in the neighbourhood. As an immediate measure they provided shielding by covering the identified high-radiation locations with metal sheets to reduce the radiation levels. The designated emergency response agencies of Department of Atomic Energy (DAE), Government of India were notified, who swung into action and in an overnight operation on April 8, 2010 they were successful in locating and securing the radioactive pieces safely into shielded containers. As a result, by forenoon of April 09, the area was declared safe from radiological considerations. The doses received by the experts and workers who performed the recovery operation were monitored and found to be within specified limits. AERB representatives were present at site during the entire operation.
As a follow up to the above incident, radiation survey of scrap metal shops in neighbouring areas was carried out. Elevated radiation level in one of the scrap metal shops located around 500 m. away from the earlier ones was detected. Subsequent search operation involving experts from Units of DAE and National Disaster Response Force (NDRF) was successful in recovery of two additional radioactive Cobalt-60 sources. One more Cobalt-60 source was recovered from the possession of a patient admitted to another hospital in Delhi. A subsequent radiation survey of the entire market area encompassing surroundings of several hundred shops was carried out to rule out the presence of any additional sources. No elevated radiation levels were found in all the areas surveyed. This indicated absence of any more radiation sources in the area. Only some low level contamination left by dust particles of cobalt was detected in a number of spots. By May 2010 the entire Mayapuri scrap market area was cleaned up including removal of contaminated soil-and declared open for public access and habitation. Concretization of the road in front of the affected shops was also done.
The dose assessments indicated that the scrap metal dealer who had reported to the hospital with radiation injuries has received a dose of 3.7 Gy. A total of 7 patients with radiation induced symptoms reported in various hospitals. Their assessed doses through bio-dosimetry were in the range of 0.4 Gy to 3.7 Gy. One of the affected persons who had received a radiation dose of 3.1 Gy died in the hospital. All other persons were discharged from the hospitals by May 24, 2010. Subsequent investigations established that the radioactive Co-60 sources were from an old gamma cell (Model No 220) made by Atomic Energy Canada Ltd. The gamma cell had 16 pencils and each pencil had 7 slugs. The total activity content when the cell was imported was 3978 Ci and the present activity content is 18.6 Ci. The source was purchased by Delhi University in 1969 and was not being used for about last 15 years. This was auctioned by the University in Feb 2010. All the radioactive sources originally present in the gamma cell were recovered and accounted for their number and source strength. This was done by counting of the recovered cobalt slugs in the hot cells. Facilities and equipment that use Co-60 are required to be individually licensed / authorized by AERB. Furthermore, replacement of Co-60 in these facilities / equipment needs AERB consent, which is granted on the basis that the used Co-60 is returned safely to its original supplier. The unauthorized disposal of the gamma cell as a scrap is in violation of the Atomic Energy (Safe Disposal of Radioactive waste) Rules, 1987 and the Atomic Energy (Radiation Protection) Rules 2004. In view of this, AERB issued a show cause notice to the University and advised the university to suspend forthwith all activities involving the use of radiation sources.