The importance of keeping track of the growing number of radiological sources distributed to users across the country has been underlined yet again.
Replying to a calling attention notice on April 19 in the Rajya Sabha on the radiological accident at Mayapuri in Delhi, Minister of State for Atomic Energy Prithviraj Chavan claimed that India had strict rules and regulations to keep track of radiological sources registered with the Atomic Energy Regulatory Board (AERB), and that the radioactive sources found in Mayapuri had to be of foreign origin. The subsequent discovery by the Delhi Police that the source that caused severe radiation poisoning to seven persons came from the Chemistry Department of Delhi University did not really alter this fact because it was a device imported in 1968. Whether it had gone into the inventory of the AERB remains to be established. If it had, the obvious question is how it went off the radar.
The regulatory system of inspection and monitoring put in place by the AERB, though detailed and elaborate, is actually not fool-proof. There have been instances year after year of loss and theft of sources from installations, particularly industrial sites. Most of these incidents, however, are not due to the inadequacy of the AERB's regulatory system but due to non-compliance and laxity on the part of the end-users. The Delhi University example shows this.
It is ironic that shortly before the Mayapuri incident, the AERB had issued revised regulations pertaining to safety and security of sources and announced a special meeting on ‘Regulatory Aspects of Safety and Security of Industrial Radiography Sources' on April 22. Interestingly, an AERB circular accompanying the announcement said: “In view of the recent incidents of theft of exposure devices from source storage pit, there is need to enhance the physical security of exposure devices at every radiography work site… Hence, all radiography companies are required to provide [an] additional chain in the pit for anchoring the exposure device… Also, it is necessary to provide adequate physical security arrangements to ensure safe and secure storage of industrial gamma radiography exposure devices… (emphasis added)”
There have been many cases of thefts and other unusual occurrences reported by the AERB over the years. The number of such incidents is not large considering that thousands of radiological sources have been distributed to users all over the country. But the seriousness of the radiological accidents demands that there should be zero-tolerance to such incidents. The periodic occurrences suggests that it is well within the realm of possibility that even domestic radioactive devices, supplied by the Board of Radiation and Isotope Technology and registered with the AERB, could end up in a scrap market. Such instances have occurred in the past and it is only luck that ensured that none of them resulted in Mayapuri-like havoc.
In 2004, an industrial radiography source with a relatively high activity of 2.5 Curies (Ci) of Iridium-192 was stolen from the pit room of a radiography institute. AERB experts, with the help of the police, tracked it down to a scrap dealer and, fortunately, recovered it intact. A failure of the search could have resulted in a significant radiological accident. The same year, a nucleonic gauge (meant to measure thickness) containing about 190 mCi of Co-60 (a much weaker source) that was lying unattended for long was inadvertently sold to a scrap dealer in an auction. The dealer cut it open with a gas cutter, resulting in damage to the source capsule. This led to widespread radioactive contamination of the dealer's premises. Fortunately it was a weak source and did not cause serious harm to people or the environment. The Delhi University-Mayapuri case was a similar one, but the source was much stronger and the consequences were severe.
In August 2003, three spare level gauges, each containing a Co-60 source, though of mild activity, were stolen from the radioisotope storage room of the R&D department of Tata Steel in Jamshedpur. On investigation, the police concluded that they had been pilfered two months earlier by scrap thieves by boring the storage room wall. The stuff reached scrap dealers in Delhi via Kolkata. Search operations both in Delhi and Kolkata could not, however, recover the gauges with the sources. Other reported incidents have included the following, some which border on the hilarious:
— On the night of August 26, 2009, an industrial radiography device of a company fell from a vehicle during transportation from Pune to Mumbai by road at Pimpri. AERB officials, with the help of the police, found that it had been picked up by a group of youngsters and taken to a village. From there it was recovered the next evening, fortunately intact.
— On January 22, 2009, a Chennai-based firm reported the loss of an industrial source. The AERB found that an employee had stolen the device and thrown it out. The AERB located it.
— On September 9, 2008, a 2 Ci Ir-192 industrial radiography exposure device belonging to a Delhi-based company was apparently stolen from the Hazrat Nizamuddin railway station while the radiographer was boarding the train. Despite extensive efforts, it could not be located.
— In 2007, two instances of theft of radiography Ir-192 sources of fairly high strength from the source storage pit were reported: one from a fertilizer unit at Jagadishpur near Lucknow, and another from Tata Steel, Jamshedpur. Despite extensive search at many locations, including of scrap dealers, the devices could not be traced.
— In 2006, a fairly high activity Ir-192 radiography source was lost while being transported in an autorickshaw. Despite an extensive search operation the device could not be located. If it ended up in a scrap market, there is the danger of exposure to the environment.
— In May 2005, two Ir-192 sources of moderate activity were stolen from an industrial unit, but neither the AERB nor the police could locate them. In August 2005, an industrial radiography agency in Navi Mumbai reported a fairly strong Ir-192 source, along with the flexible ‘pigtail' attached to manoeuvre the source, was stolen. The AERB, with police assistance, found that a person working for another agency had stolen the source and thrown it into the Vashi Creek. Search operations with the help of the Navy were carried out, but the source could not be located.
— In July 2002, a radiography camera with Ir-192 source of fairly high activity, kept in a locked briefcase, was lost in a public bus in which the radiography personnel of an agency were travelling. The AERB officials and the police searched the entire length of the highway they had travelled, in vain. The baggage was either stolen or had slipped out of the rear luggage hold, the AERB concluded.
Though these radiography devices are portable, they are relatively heavy (tens of kg on an average). Interestingly, however, individuals seem to manage to steal or pilfer these devices relatively easily.
More pertinently, transportation of these devices by public transport vehicles is explicitly prohibited under AERB regulations. But these incidents indicate that industrial and other users do not seem to be aware of the potential dangers their violation of the regulations pose to the public at large. The Mayapuri-Delhi University case is an example where even people who should be aware of the risks were callous.