The Mumbai Mirror, an Indian daily has been continuously publishing posts/reports highlighting the exposures from mobile towers and asking for regulation on the installation of towers and control on usage of mobile phones by children and others. The latest report published in the Mumbai Mirror (May 18, 2010) says that “half an hour of cellphone use a day increases brain cancer risk”. The study was undertaken by the World Health Organization (WHO).
The research findings are as expected. None of the mobile manufactures or the service providers seem to be bothered about the health effects which are being only confirmed over time by research. According to International Communication Union, there were estimated 4.6 billion phone subscriptions at the end of last year! This is becoming a global problem which needs urgent intervention by the countries world-over.
The International Commission on Non-Ionizing Radiation Protection has recommended the relevant safety standards which are accepted internationally. Why not enforce the standards? Governments should respect the public concerns and give clear instructions to all concerned without unduly inducing radiophobia towards radiation.
Saturday, May 22, 2010
Thursday, May 6, 2010
All missing Cobalt-60 pencils recovered
It is reported that the BARC expert team has recovered all the cobalt pencils from the scrap yard at Mayapuri, Delhi, after a month of exposure of eight people to the gamma radiation from the Cobalt-60 source. The sources were inside the Gamma Cell which was sold (as junk sale) by the Delhi University and was dismantled by the scrap dealer. It is reported, however, that there were 48 slots inside the Gamma Cell for keeping the pencils. Only 16 pencils are recovered. What about other pencils? Dummy pencils?
The incident was reported to the International Atomic energy Agency and the agency after though investigation will assign severity level for the incident. The level may be probably 3 or 4. The International Nuclear Event Scale (INES) is made up of 7 levels of increasing severity; 3 incident-levels and 4 accident-levels.
There are issues to be resolved by the concerned authorities:
1. Common man wants to know the action taken against the persons responsible for such an event. This is a criminally careless action. The action should severe enough to serve as a warning to others.
2. Investigation should be ordered to check/confirm whether such so-called decayed sources are still available in other institutes. India Government should ensure that such incidents are not repeated.
3. Proper inventory of all sources lying in research institutes and in industrial units should be made by the national regulator, AERB on Cradle to Grave basis.
4. The government should publish full report on the incident and all information/actions taken should be made transparent.
The incident was reported to the International Atomic energy Agency and the agency after though investigation will assign severity level for the incident. The level may be probably 3 or 4. The International Nuclear Event Scale (INES) is made up of 7 levels of increasing severity; 3 incident-levels and 4 accident-levels.
There are issues to be resolved by the concerned authorities:
1. Common man wants to know the action taken against the persons responsible for such an event. This is a criminally careless action. The action should severe enough to serve as a warning to others.
2. Investigation should be ordered to check/confirm whether such so-called decayed sources are still available in other institutes. India Government should ensure that such incidents are not repeated.
3. Proper inventory of all sources lying in research institutes and in industrial units should be made by the national regulator, AERB on Cradle to Grave basis.
4. The government should publish full report on the incident and all information/actions taken should be made transparent.
Wednesday, May 5, 2010
Radiation emergency in Mayapuri, Delhi
As per the reports, a Gamma Cell imported in 1968 from Canada, was being used for research at the Delhi University. It was lying unused since 1985 i.e., for the last 25 years. The Cell contained a high-intensity radioactive source, Cobalt-60 with a half life of about 5.3 years. The source is well-shielded inside the cell using lead or depleted uranium as shield material. The source is safe for handling when it is inside the shield. Without shield, it is an open, bare source which can cause severe radiation exposure to people nearby. This is a typical radiation emergency situation, which requires radiation protection experts to manage.
In every 5.3 years, the radioactivity will be reduced by half of the existing activity. The sources lose considerable radioactivity after some years and are called decayed sources (misnomer), the sources still will have enough radioactivity, the exposure to which can be fatal to humans. Such decayed sources are required to be sent to either to the supplier or to the national waste management facility at BARC. Such transfers can be done only after consulting the national regulatory body, Atomic Energy Regulatory Board (AERB) located at Anushaktinagar, Mumbai. In this case, it was just auctioned as metallic scrap material in February this year.
Legally, such radioactive source shall never be disposed off through auction or otherwise to any scrap dealer. All institutions using radioactive sources are required to inform the AERB regarding possession of the sources. AERB is supposed to keep inventory of all the radioactive sources existing with institutions/Universities and in industry. Large numbers of radioactive sources are used in industrial radiography a NDT used in quality control programs.
In every 5.3 years, the radioactivity will be reduced by half of the existing activity. The sources lose considerable radioactivity after some years and are called decayed sources (misnomer), the sources still will have enough radioactivity, the exposure to which can be fatal to humans. Such decayed sources are required to be sent to either to the supplier or to the national waste management facility at BARC. Such transfers can be done only after consulting the national regulatory body, Atomic Energy Regulatory Board (AERB) located at Anushaktinagar, Mumbai. In this case, it was just auctioned as metallic scrap material in February this year.
Legally, such radioactive source shall never be disposed off through auction or otherwise to any scrap dealer. All institutions using radioactive sources are required to inform the AERB regarding possession of the sources. AERB is supposed to keep inventory of all the radioactive sources existing with institutions/Universities and in industry. Large numbers of radioactive sources are used in industrial radiography a NDT used in quality control programs.
Monday, May 3, 2010
Gamma cell – Mayapuri incident
Gamma cell (also called gamma irradiator) is used for irradiation of materials to study the effects of radiation. The cell generally contains high energy gamma radiation sources like cobalt-60. The cobal-60 is artificially produced in nuclear reactor by neutron irradiation of Cobalt-59 isotope. The Cobalt-59 is naturally occurring isotope and is not radioactive. Cobalt-60 has a half life of 5.3 years. This only means, in 5.3 years, the radioactive content of the source becomes one-half of the initial radioactivity. As per the decay law, in 2, 3, 4, half lives (in 10.6, 15.9 and 21.2 years), the radioactivity will reduce by one-fourth, one-ninth and one-sixteenth of the initial activity. It will take many more years for the radioactivity to come down to any acceptable, safe levels.
In some news papers, it was reported that the source found in a Mayapuri (Delhi, India) scrap dealer was showing radiation level of 1000 R/h (R is the unit of exposure rate, Roentgen per hour). It is also reported that the gamma cell was bought in 1968. That means the source has decayed by 8 half-lives. The initial dose rate must have been (8x8=64) in the range of 64,000 R/h.
Invariably the gamma cells are accompanied by the operating manuals and the design details. These documents, if available will give details about the number of source pencils and their configuration inside the cell which will vary depending on the required radiation dose for irradiation.
Sources of this high dose levels are never handled openly. They are handled remotely in specially designed and well-shielded enclosures called Hot Cells. The gamma cell is also a well-designed enclosure with the radiation source inside the lead or depleted uranium shield to prevent radiation leakage outside the cell. The design is such that only authorized persons with lock & key arrangement can remotely operate the source for irradiation of sample materials.
In some news papers, it was reported that the source found in a Mayapuri (Delhi, India) scrap dealer was showing radiation level of 1000 R/h (R is the unit of exposure rate, Roentgen per hour). It is also reported that the gamma cell was bought in 1968. That means the source has decayed by 8 half-lives. The initial dose rate must have been (8x8=64) in the range of 64,000 R/h.
Invariably the gamma cells are accompanied by the operating manuals and the design details. These documents, if available will give details about the number of source pencils and their configuration inside the cell which will vary depending on the required radiation dose for irradiation.
Sources of this high dose levels are never handled openly. They are handled remotely in specially designed and well-shielded enclosures called Hot Cells. The gamma cell is also a well-designed enclosure with the radiation source inside the lead or depleted uranium shield to prevent radiation leakage outside the cell. The design is such that only authorized persons with lock & key arrangement can remotely operate the source for irradiation of sample materials.
Subscribe to:
Posts (Atom)