Date:15/04/2010 URL: http://www.thehindu.com/thehindu/seta/2010/04/15/stories/2010041551311400.htm
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Lessons to be learnt from Delhi radiation incident
Photo: K. PIchumani
The source: Virtually all instances of steel contamination seem to have been caused by radioactive sources which came with imported scrap. —
At 12:45 hrs on April 7, 2010 the Atomic Energy Regulatory Board (AERB) received a fax message from Indraprastha Apollo Hospital, Delhi stating that a scrap metal dealer admitted to the hospital showed symptoms suspected to be caused by radiation exposure.
Six more workers who also exhibited similar symptoms were admitted elsewhere. On receiving the information, two AERB officers who were already in Delhi inspected the shop and its surroundings, identified high radiation levels and promptly shielded some suspected high radiation locations with metal sheets to reduce the radiation levels.
As per the procedure in place, a team of scientists from Bhabha Atomic Research Centre (BARC)and the Narora Atomic Power Station , mobilized by the Crisis Management Group of the Department of Atomic Energy (DAE) and scientists from AERB visited the site again and restored normalcy by safely removing the sources into appropriately shielded containers. By April 9, 2010, the radiation levels at the site became normal background radiation levels.
“It was indeed a difficult operation; we collected cobalt-60 sources of high strengths in the form of wires under trying circumstances and secured them in special containers. We instituted strict dose control procedures which ensured that the radiation doses to us were within limits,” said Dr. K.S.Pradeep Kumar, Senior Scientist and Head, Emergency Response System and Methods Section.
“We learnt a few lessons. The team from Narora brought many tools and accessories; their support proved to be very crucial,” he clarified. He paid compliments to the excellent cooperation extended by the Delhi police.
A handful of radiation incidents in which persons got exposed to very high radiation doses occurred in India. Most of the cases were because of gross violation of safety procedures in handling industrial gamma radiography sources.
In the most serious case, a railway gang man received high dose as he kept gamma source in his pocket for a few hours. The source was lost in transit because of negligence of radiation workers in a company. Follow up action led to the winding up of the company.
The victim pocketed the shining object assuming that it is valuable. He was admitted into BARC Hospital initially for three months and was followed up for one and a half years. He survived after several skin drafts and other procedures.
The Delhi incident was a serious one. That such incidents were rare would be poor consolation for those seven persons who were exposed to radiation. There must be zero tolerance to such events.
AERB had suggested several preventive measures ( The Hindu, Nov 13, 2008). In the light of a few steel contamination incidents, AERB proposed to put in place a multi layered radiation check system ( The Hindu, February 26, 2009). These need closer review, strengthening and more effective enforcement.
Many scrap dealers have bought radiation monitors. The proposal to erect radiation monitors at major ports is yet to be implemented. Since virtually all instances of steel contamination seem to have been caused by radioactive sources which came along with imported scrap, radiation monitors must be installed urgently at all ports. The radiation incident at Delhi must be considered as the final wake up call. There are plans to equip selected police stations in major cities with radiation monitors. The task is humongous but achievable through dedicated efforts.
Radiation exposure from “orphan sources” was a topic of discussion in many meetings held by the International Atomic Energy Agency (IAEA) since 1998.An initial review indicated that, more than 110 countries may not have minimum infrastructure to properly control radiation sources (IAEA, 1999).
Since 1990, 300 radioactive sources were recovered from Georgia. There were instances in which intense radiation sources used in agricultural research such as mutation studies were found abandoned in trucks
In the United States alone, the Nuclear Regulatory Commission (NRC) annually receives about 200 reports of lost, stolen or abandoned radioactive sources. This is disconcerting as U.S. has a stringent regulatory system. AERB receives less number of reports annually, presumably because we have far less number of sources in use. Also as in U.S., AERB has a very effective system to track high intensity sources.
K.S. PARTHASARATHY
FORMER SECRETARY, AERB
ksparth@yahoo.co.uk
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