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A Tribune Exclusive
Cobalt-60 imported as industrial waste?
Aditi Tandon
Tribune News Service

New Delhi, April 11
It is highly unlikely that cobalt 60, the radioactive isotope that made it to a scrap dealer’s shop in West Delhi a few days ago and left five persons critically ill, came from hospital or industrial waste originating in India.

Scientists investigating the presence of the radiation source in public — a matter that raised concerns about India’s ability to handle nuclear waste — have almost ruled out the possibility of the detected cobalt 60 originating indigenously. They believe it most probably came as part of the industrial waste imported from abroad, from international scrap markets, to be more specific. That means the said source made it through the customs - a clear lapse.

Reason the scientists are extending for this possibility is this - the Department of Atomic Energy is the sole supplier of cobalt 60 and other radiation sources for use by indigenous industry or hospitals. The Board of Radiation and Isotope Technology under the DoAE is the principal supplier of such things and follows a strict supplying, monitoring and retrieving mechanism to ensure safe use and disposal of radioactive waste.

Any institution wanting cobalt 60 must first approach the DoAE to get a licence for procurement. When the source loses its radioactive strength, the said institution must again approach the DoAE for its disposal. Only when the procured source is disposed of does the institution get access to new source.

Speaking exclusively to The Tribune today, Dr SK Malhotra of the Bhabha Atomic Research Centre , who is part of the team investigating cobalt 60’s presence in Delhi, ruled out the detected cobalt’s origin to any hospital.

“This source is not from any hospital because the cancer therapy machines and other medical equipment use cobalt pencils or pellets. The source we detected in Delhi is in the shape of a wire. It is essentially industrial waste, but not locally generated. The highest probability is that it is part of the industrial waste imported from abroad, most likely from international scrap markets. How this source made it through the customs check is something for the police to investigate. The customs officials are trained to detect radioactive material.”

The scientist also explained why indigenous tracing of detected cobalt 60 was being ruled out. “Since we are the sole suppliers of cobalt 60 and our safety record is fairly strong, it is highly unlikely that the source under study came from indigenous industrial waste. It looks like imported from abroad. We are investigating the material for signatures and source of the country of origin and will inform the police accordingly. The investigation will take time. We have to first disentangle the cobalt from the junk we picked up in Delhi in a hurry to avoid prolonged exposure to radiation,” Dr Malhotra said, pointing to thriving scrap markets of India, where imported metallic junk fetched handsome prices.

In India, the procurement and disposal of cobalt 60 and radioactive sources is regulated by the Atomic Energy Regulatory Board, Mumbai, which implements the Atomic Energy (Radiation Protection) Rules, 2004. These rules apply to institutions using ionising radiation for medical applications, such as teletherapy and brachytherapy units, nuclear medicine labs, diagnostic X-ray installations, including dental X-ray, mammography and interventional radiology and CT scan. They also cover units using sealed radiation sources for industrial radiography. Every handler of radioactive material must have a radiation safety officer, who becomes the custodian of such material. Any lapse in the disposal invites cancellation of the licence to handle the material by the AERB.

As regards cobalt 60 disposal, an institution must first write to the AERB that sends its people to the site for inspection and then recommends packaging strategy. Cobalt 60 is normally transported in lead caskets to BARC, where scientists send it to engineered disposal systems located at Trombay and Kalpakkam.

ALL ABOUT COBALT

Cobalt and cobalt-60 comes from…

• Commercial use in linear accelerators.
• As a by-product of nuclear reactor operations, when structural materials, such as steel, are exposed to neutron radiation.

• length of exposure
• distance from the source (for external exposure)
• whether the cobalt-60 was ingested or inhaled.