Radiation shock

Published : May 21, 2010 00:00 IST

Experts examining the scrap loaded in a vehicle to identify the sources of radiation, on April 9.-SHIV KUMAR PUSHPAKAR

Experts examining the scrap loaded in a vehicle to identify the sources of radiation, on April 9.-SHIV KUMAR PUSHPAKAR

THE radiological accident in early April at the Mayapuri scrap metal bazaar in New Delhi, which caused radiation poisoning to seven persons, one of whom has since died, is believed to be the result of abandoned radiation sources having got mixed with scrap metal originating from various places, including foreign countries. The scrap industry recycles such scrap metal, largely iron, into low-grade steel, which is then converted into various products or is exported. Other metals, such as zinc, copper and nickel, too are extracted, but in smaller quantities. If radioactive sources too get melted along with the scrap during the smelting process, the products would become radioactively contaminated.

According to the Atomic Energy Regulatory Board (AERB) of the Department of Atomic Energy (DAE), which oversees and regulates all nuclear and radiological activities in the country, detailed search operations in the entire market area covering several hundred shops following the accident resulted in the recovery of eight sources from one shop, where six persons were affected, and two more (a few days later) from another shop located 500 metres away. In addition, an individual was found to be in possession of one more source.

All these sources have been identified with the help of a portable spectrometer to be cobalt-60 (Co-60), a radioactive isotope of the element cobalt that emits gamma rays. Co-60 sources are used in industrial gamma radiography cameras for non-destructive testing (NDT), nucleonic gauges for thickness measurements and gamma irradiators and also in medical brachytherapy devices. Most of the devices recovered from Mayapuri are apparently industrial radiological sources, which generally are of much higher activity (tens to hundreds of Curies, Ci) as compared to sources used for medical and research purposes (milli Ci). One of them seems to be a blood irradiator, used for irradiating blood products, which is usually a bundle of Co-60 pencils packed in a unit.

Since the sources seem to have been cut open and rendered bare without even the cladding, let alone the heavy metal radiation shielding (usually lead or depleted uranium) and the outer packaging with symbols and markings, and that too badly mangled to enable any identification of the origins of the sources, it is not clear if the number of sources refers to 10 individual units or 10 pieces of a smaller number of sources. Some lead was also found in the premises. Apparently lead has its own market and fetches a good price and hence the attempt to dismantle the device for disposing of the lead shielding.

These sources do not seem to be of the kind supplied to Indian users by the Board of Radiation and Isotope Technology (BRIT) of the DAE and registered with the AERB. While Co-60 sources, both indigenous and imported, supplied by BRIT are in the form of pellets encapsulated in stainless steel, the Mayapuri sources were in the form of wires or pencils encapsulated in cylinders, according to the AERB. Also the casing of some of the sources seems to be of aluminium, which BRIT does not use. Also, the blood irradiator seems to be 20-30 years old. The AERB was established only in 1983. This could mean that even sources legally imported into the country earlier than 1983, which may not have been registered with it, could find their way into the scrap market.

All these suggest that the sources are perhaps from abroad and have found their way into the countrys scrap market. Only the last leg of their journey across continents seems to be known that they came from Faridabad, an industrial hub in Haryana close to Delhi. For the AERB and the National Disaster Management Authority (NDMA) to pin down the exact origin of the scrap and the radioactive sources through investigations based on this bit of information alone can be a formidable task given the extent of scrap imports into the country and the countrywide spread of the scrap-to-steel industry.

Radioactive contamination of scrap-derived steel products exported from India is not a new danger. Perhaps the first report of radioactively contaminated steel exported to the United States was in 1991. Since then there have been several incidents of such exports and subsequent complaints to the Indian authorities by the importing countries around the world, which shows the unmonitored and unregulated nature of the scrap market and industry. Contaminated steel products that have been exported have included steel door handles, manhole covers, steel tension bars, steel wires, metal components used in leather bags, metal scraps used for packaging, and so on. Clearly, the danger of contamination exists not only in exported items but in domestic steel products, including household steel goods and appliances.

The most recent report came in Der Spiegel in February 2009, which said that during 2008-2009 the authorities in Germany detected large amounts of radioactive steel in factories in 19 incidents across 12 States. The products included steel bars, cables, chippings and valve housings. These were all found to be contaminated with radioactive cobalt. Between August 2008 and February 2009, as much as 150 tonnes of contaminated steel had been seized. Some of it had been sent back to India after informing the authorities, the report said. The rest had been stored by the companies pending its safe disposal by waste radioactive management authorities. The newspaper said that the imports had apparently been made from three steelworks, in particular Vipras Castings Ltd, a company near Mumbai.

Vipras Castings was also one of the companies implicated in radioactive steel exports to France a little before the German incident. In October 2008, the elevator manufacturer Otis decided to replace 30,000 steel lift buttons from 350-500 sites across France after these were found to be radioactive. According to the French Nuclear Safety Authority (ASN), about 20 workers at the plant of the firm Mafelec, which manufactured the buttons, were found to have been exposed to 1-3 milliSieverts (mSv), levels of radiation that are above the safe limit of 1 mSv for a whole year (for non-nuclear industry workers). The firm had delivered these buttons to Otis between August and October 2008.

According to ASN, steel received from five Indian companies was found to be contaminated with Co-60. These companies were identified as Bunts, Laxmi Steel, SKM Steels, Vipras Castings Ltd and Pradeep Metals Ltd, all Maharashtra-based companies. Mafelec had supplied buttons to Germany as well and these too had been called back. However, steel components received prior to August 2008 were apparently free of radioactivity, which the company used for replacing the contaminated ones.

According to the AERB, radioactively contaminated steel was also reported in products exported to the U.S., the United Kingdom, Spain and Turkey. Investigations carried out by the AERB apparently revealed that the contamination originated from a single steel foundry. Inspection of 20 steel recycling factories found radioactive-contaminated items in some of them. Similar contaminated steel exports to the U.S. and the U.K. during 2006-07 were traced to factories in Kolkata. The AERB conducted inspections of 24 factories in Kolkata and located radioactive-contaminated items in six of them.

While such cases were reported rarely during the 1990s, as a result of increased globalisation there has been a spurt in the number of reports of contaminated steel being produced from imported scrap metal since 2004. More pertinently, radiological sources are used in a much larger number of countries than those having a nuclear power programme and an associated regulatory system. Security controls over radiological sources in such countries are weak and these may not be safely disposed of after use and thus are likely to get mixed with scrap and exported.

Indeed, the Directorate General of Foreign Trade has been issuing appropriate amendments since 2004 to the import regulations for metal scrap under the Exim Policy of 2004-2009, which significantly states that the exporter of scrap (shredded or unshredded) shall furnish, among other documents relating to the export, a pre-shipment certificate to the effect that the consignment does not contain any type of radioactive-contaminated material in any form as well as a copy of the contract between the importer and the exporter stipulating that the consignment does not contain any radioactive-contaminated material in any form. The policy has also stipulated that while shredded metal scrap could be imported through any port, unshredded/compressed/loose scrap could be imported through the following 17 ports: Chennai, Kochi, Ennore, Jawaharlal Nehru Port Trust (Navi Mumbai), Kandla, Mormugao, Mumbai, New Mangalore, Paradip, Tuticorin, Visakhapatnam, ICD (International Container Depot) Tughlakabad, Pipava, Mundra, Kolkata, ICD Ludhiana and ICD Dadri, Greater Noida.

Given that there are only a limited number of entry points into the country, a strict surveillance of imported scrap is certainly feasible. But clearly, this is not happening.

With a variety of radiation monitoring instruments available in the market and it being mandatory for the ports to ensure that imported metal scrap is not radioactive, the fact that radioactive-contaminated scrap continues to slip into the country shows the extreme laxity in the enforcement of rules in our ports.

Replying to a calling attention notice in the Rajya Sabha on April 19, Minister of State for Atomic Energy Prithviraj Chavan claimed that the country had very strict rules and regulations for keeping track of radiological sources registered with the AERB and that the radioactive sources found in Mayapuri had to be of foreign origin. So can tightening the entry gates into the country with sophisticated radioactivity monitoring devices alone completely eliminate such radiological accidents? Not really, as we shall see now. While other indications seem to suggest that the Mayapuri case involved only imported sources, the regulatory system of inspection and monitoring, though detailed and elaborate, is not completely foolproof given the yearly instances of loss and theft of sources from various installations across the country, particularly industrial sites. Most of these incidents, it must be said, are not because of inadequacy of the AERBs regulatory system but because of non-compliance and laxity on the part of the industrial units.

The AERB periodically reports violations of regulations by industrial units. These include loaning of radiography exposure devices without prior approval of the Board, insufficient shielding of the installation, inadequate physical security for exposure devices, unauthorised radiography source movements from one site to another, non-declaration of radioactive consignment in transportation documents, conduct of radiography work at unauthorised sites by trainee radiographers, improper maintenance of log book records and non-submission of relevant documents to the AERB. Such violations do attract penalties from the Board, including suspension of authorisation and licence, and withdrawal of the certificates of radiography personnel.

Unusual occurrences, some of them bordering on the hilarious, have been reported by the AERB over the years (see box). Though the number of such incidents may not be large compared with the large number of radiological sources distributed to various users all over the country (see table), the regulatory framework should be one of zero-tolerance towards such incidents because of the potential radiation hazard that these pose to the general public. But, unfortunately, every year the AERB does receive reports of a few cases.

But the Mayapuri incident is perhaps the severest radiological accident that the country has witnessed so far. While that may have been because of sources that made their way into the country illegally, given the widespread use of radiological sources in the country today it is well within the realm of possibility that some domestic radioactive devices could actually end up in a scrap market even if there is the strictest control over imports of scrap metal. Such instances have occurred in the past and it is only chance that none of these has resulted in a Mayapuri-like havoc.

Indeed, in the year 2004, an industrial radiography source with a relatively high activity of 2.5 Ci of Iridium-192 was stolen from the pit room of a radiography institute. The discovery of the theft led AERB experts, helped by the police, to a scrap dealer and, fortunately, to the recovery of the source intact. Failure in the search could have resulted in a major radiological accident or the use of contaminated products at the very least.

In the same year, a nucleonic gauge 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 open the device with the gas cutter, which resulted in damage to the source capsule. This led to widespread radioactive contamination on the premises of the scrap dealer. Two things led to this incident: one, the supplier failing to collect the source for disposal in time, and, two, the user failing to monitor its safe storage and ensure its security. Fortunately, it was a weak source and did not cause any serious harm to people or the environment. But clearly, this could happen with a strong source as well.

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 TISCO, Jamshedpur. On investigation, the police concluded that the sources had been pilfered two months earlier by scrap thieves by making a hole in the storage room wall and had reached prominent scrap dealers of Delhi via Kolkata. Search operations both in Delhi and Kolkata could not, however, help recover the gauges with the sources. Despite the apparently enhanced security measures put in place at TISCO, another incident was reported in 2007 indicating that these were not adequate.

It is in a sense ironical that shortly before the Mayapuri incident, the AERB had issued a number of revised regulations pertaining to the safety and security of sources and announced a special meeting on Regulatory Aspects of Safety and Security of Industrial Radiography Sources, to be held on April 22, to provide a forum for interaction with radiography users. An AERB circular accompanying the announcement said the following: 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 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).

Given the large number of sources in the country and their highly dispersed nature in thousands of institutions, industrial units and medical facilities, keeping a continually updated historical record of these can be a difficult proposition. One can imagine the high probability of sources being orphaned, sources that are lost from regulatory control because of loss, theft, pilferage, and so on. The AERB does have a cradle to grave control system that is exercised in three stages: in a pre-licensing stage, during its useful life, and after its useful life.

During the useful lifetime, the licensees are supposed to send periodic status reports. Upon completion of useful life, the user is supposed to return the source to the original supplier; if it is imported then it is shipped back, and if that is not feasible the Waste Management Division (WMD) of the Bhabha Atomic Research Centre (BARC) has the responsibility of disposing of the source. A computerised national registry is apparently maintained at the AERB, which is constantly updated on the basis of information from the licensees.

While the AERB does report annually some of the unusual radiological incidents that come to light, it does not put out data on the number of orphaned sources every year. Keeping track of sealed radioactive sources is one area where the inventory and record-keeping system perhaps needs strengthening. Human resource constraint is certainly a limiting factor.

For example, while there are 1,485 institutions in which the 7,850 nucleonic gauges are located, only 16 inspections were done during 2008-09. Similarly, while 249 institutions have radiotherapy units, only 10 inspections could be done; for 505 industrial radiography units only 39 inspections were done. Of course, given the nature of installations and the nature of operations, not every installation needs to be inspected every year. But even in terms of sampling an adequate number, the number of inspections carried out by the Board would seem to fall short.

In the context of the Mayapuri incident, it needs to be pointed out, especially given the ongoing debate on the proposed civil nuclear liability Bill, 2009 that there is no law at present in the country that can be invoked for the immediate payment of compensation to radiological accident victims. The Public Liability Insurance Act (1991), which provides immediate relief to persons affected by accidents occurring while handling any hazardous substance and for matters connected therewith or incidental thereto, specifically excludes all nuclear including radiological accidents.

The proposed civil nuclear liability Bill, too, explicitly excludes such cases. Nuclear material, as defined in the Bill, does not include radioisotopes which have reached the final stage of fabrication so as to be usable for any scientific, medical, agricultural, commercial or industrial purpose. So there is no provision in the Indian legislature at present for immediate relief to such victims. Relief or compensation will come only through the general tort law provisions. It is surprising, therefore, that Prithviraj Chavan should have pitched for the passage of a nuclear liability law to enable payment of compensation to radiological accident victims in his Rajya Sabha speech of April 19.

Radiological accidents are not unique to India. It is a worldwide phenomenon and the famous Goiania radiological accident in Brazil in 1988 is indicative of the potential danger that orphaned sources pose. Other famous incidents include: 1. The Ankara, Turkey, incident of 1993 where three disused Co-60 sources meant for re-export to the U.S. ended up in a family home, causing radiation poisoning to 18 people. 2. The May 1998 incident in Los Barrios, Spain, where an unnoticed caesium-137 source was melted in an electric furnace, causing radioactively polluted emissions. The radiological consequences of the incident to people were, however, minimal. 3. The Samut Pakarn, Thailand, incident in February 2000, in which a disused Co-60 radiotherapy source was stored in the open in a junkyard. This led to three deaths and affected nearly 1,870 persons living within 100 m of the junkyard.

There is heightened concern today about Radiological Security, which is increasingly perceived to be a component of Nuclear Security. The International Atomic Energy Agency (IAEA) defines the term nuclear security thus: The prevention and detection of and response to, theft, sabotage, unauthorised access, illegal transfer or other malicious acts involving nuclear material, other radioactive substances or their associated facilities. The term Nuclear Security thus subsumes security of radiological sources in the areas of research, medical and industrial applications.

In contrast to weapons security aimed at ensuring that weapons-grade fissile material does not fall into the wrong hands (non-state actors), where the problem is localised and tractable, radioactive sealed sources in their diverse applications are widespread. A potential danger of lost radioactive sources is that they can be used in Radiological Dispersal Devices (RDDs). An RDD, or a dirty bomb, is a conventional explosive device in which the radioactive material has been so added that, on explosion, there will be dispersal of radioactivity in the environment. An RDD itself will not lead to any fatality. The fatalities, if any, would primarily be due to the explosion. However, it may contaminate a reasonably large area, besides causing widespread panic among people. Radioactive material from orphaned sources can also be generally released into the environment, say the water supply system, posing a danger to a sizeable population. Instead of weapons of mass destruction, in the case of pilfered radiological sources, we have weapons of mass disruption.

According to the IAEA, there is no worldwide central repository of information on radioactive sources. The total number of sources worldwide is not known, but it is generally accepted that there are well in excess of 100,000 Category 1 and 2 sources and a far greater number of Category 3 sources (sources categorised from 1 to 5, with 1 signifying sources with the highest activity and hence posing the greatest hazard). Though the terms nuclear terrorism and radiological terrorism are frequently used synonymously, the two are quite distinct. Indeed, the probability of the latter is far greater than the former and hence the need for greater security on that count.

In fact, the phenomenon of orphaned sources is widespread in the states of the former Soviet Union. Even the U.S. Nuclear Regulatory Commission (NRC) has reported that it has lost track of over 1,500 sealed sources since 1996 and more than half the number have never been traced. In fact, the U.S. National Nuclear Security Administration (NNSA) has a major ongoing programme for the recovery of orphaned sources. A European Union (E.U.) study estimated that about 70 sources are orphaned every year. A recent European Commission report estimated that about 30,000 disused sources in the E.U. that were held in local storage at the users premises were at risk of being lost from regulatory control.

President Barack Obamas much-touted Nuclear Security Summit in early April did not discuss aspects of radiological security. But it is apparent that the issue deserves much greater global concern than is evident because the risk of radiological accidents, in particular the threat from non-state actors, is far greater than the threat of use of a clandestine nuclear weapon.

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