Stable iodine prophylaxis

Despite rigorous safety systems in a nuclear reactor, there remains a finite probability that an accident can occur that can lead to the fuel in the core overheating or melting. If such an event were to occur, there is a chance that radioactive fission products may be released to the environment. The potential radiation exposure of the population will be influenced by many parameters such as: the amounts of the radionuclides released, the meteorological conditions affecting the dispersion and deposition of the released radioactive material, human and environmental factors and the effectiveness of any protective actions taken.

Isotopes of iodine particularly I-131, is likely to be important components of the release from a severe accident. Radioactive iodines can give rise to both external exposure and internal exposure (from inhalation and ingestion). Stable iodine prophylaxis is a protective action, for which preparedness arrangements can be made as part of the overall emergency response plan. This step can protect specifically against internal exposure from inhalation, and ingestion of radioiodines by consumption of I-131 contaminated milk/milk products. It should be noted that the term “iodine prophylaxis” refers to the blocking of the uptake of radioiodine by the thyroid gland after nuclear accidents.

The selective and rapid concentration and storage of radioactive iodine in the thyroid gland results in internal radiation exposure of the thyroid, Deterministic effects from thyroid exposure are hypothyroidism and acute thyroiditis. Stochastic effects from thyroid exposure are thyroid cancer and benign thyroid nodules.

As per the WHO document on iodine prophylaxis (update-1999), it recommended that in the management of nuclear reactor accidents, stable iodine prophylaxis for children up to the age of 18 years and for pregnant and lactating women be considered at 10 mGy dose, that is 1/10th of the generic intervention level dose of 100mGy for adults recommended in the IAEA International Basic Safety Standards for Protection against Ionizing Radiation.

The recommended single dosage of stable iodine for prompt administration for adults over 12 years is 130 mg of KI or 170 mg of KIO3, for children (3 to 12 years), the dose recommended is 65mg of KI and 85mg KIO3 and for infants (1 month to 3 years) the dose is 32 mg of KI and 42 mg of KIO3.

Loss-of-Coolant Accident (LOCA) – Nuclear reactors

A loss-of-coolant accident (LOCA) is a mode of failure for a nuclear reactor. If not managed properly and effectively, the results of a LOCA could result in reactor core damage. In every nuclear reactor, a separate Emergency Core Cooling System (ECCS) exists specifically to deal with the situation like LOCA.

Nuclear reactors generate heat internally in the fuel by the fission reaction, neutron with a fissile material uranium-235. This heat is removed by a coolant system to produce steam and is converted into useful electrical power. If this coolant flow is reduced, or lost altogether, the nuclear reactor's emergency shutdown system is designed to stop the fission chain reaction automatically. However, even after reactor shut down, due to radioactive decay of the fission products, the nuclear fuel will continue to generate a significant amount of heat. This decay heat needs to be taken out through secondary cooling system to maintain integrity of the fuel. If all of the independent cooling systems of the ECCS fail to operate as designed due to some reason such as failure of the pumps, this heat can increase the fuel temperature to the point of damaging the fuel and the reactor.

Damage to the reactor containment will result in the radioactive releases from the reactors. Iodine-131 and Xe-133 have half life of 8 days and 5.2 days and hence are detected in the environment in such situations. Depending upon the wind direction and speed, the radioactive isotopes will travel in dispersed form to large distances.

ICRP Publication 111, 2009

In this document, the International Commission on Radiological Protection (ICRP) provides guidance on “Application of the Commission's Recommendations to the Protection of People Living in Long-term Contaminated Areas after a Nuclear Accident or a Radiation Emergency” for the protection of the people considering effects of: the pathways of human exposure, the types of exposed populations, and the characteristics of exposures. Although, the focus is on radiation protection considerations, the report also recognizes the complexity of post-accident situations, which cannot be managed without addressing all the affected domains of daily life, i.e. environmental, health, economic, social, psychological, cultural, ethical, political, etc. The report explains how the ICRP-103 (2007) Recommendations apply to this type of existing exposure situation, including consideration of the justification and optimization of protection strategies, and the introduction and application of a reference level to drive the optimization process.

The report also considers practical aspects of the implementation of protection strategies, both by authorities and the affected population. The role of radiation monitoring, health surveillance and the management of contaminated foodstuffs and other commodities is described. The Annex summarizes past experience of long term contaminated areas resulting from radiation emergencies and nuclear accidents, including radiological criteria followed in carrying out remediation measures (Extracted for the ICRP site).

Is India prepared for radiological emergency?

Political situation in Pakistan is very fluid and the terrorist organizations/extremists have stepped up calls for Jihad against India. It is possible that they may even be in position to get their hands on the nuclear weapons in Pakistan and this is going to be matter of deep concern for the security of India. The organizations threaten nuclear war for Kashmir.

In any case, even if nuclear weapons are not used, there is good possibility the use of a radiological dispersion device (RDD) or “dirty” bomb. This is a conventional explosive wrapped in radiological material. Terrorists may use an RDD to disperse radioactive material across a populated area, causing casualties, economic damage and panic. A mere presence of radioactive contamination will create full-blown media coverage and the nuclear program envisaged for the benefit of the country will be in jeopardy.

Is India prepared for such an eventuality, called radiological emergency in any part of the country in terms of trained man power, equipment and logistics?

The Jaitapur nuclear project is courting too many risks

An article on Jaitapur nuclear project, published in one of the leading news papers in India today seems to be misleading the common man who is not aware of the radiation risks and nuclear power reactor safety. The project is not courting too many risks. The article shows the lack of in-depth knowledge of the writer on the subject.

It is very difficult to comprehend the real reasons for someone to delay the project causing avoidable delays in starting and completion of India’s infrastructure projects. India needs power for its development. Nuclear is undoubtedly the cleaner power as compared to coal and gas.

There are insignificant numbers of fatalities reported from incidents/accidents in nuclear reactors! There is absolutely no justification for over-protection. Today, any major power project or other infrastructure projects commonly consider and provide for seismicity, floods and terrorist activities while designing the plants/projects. Safe management, including transport of radioactive waste is well established and regulated rigorously in Indian nuclear facilities. France is one of the countries which believed strongly in the use of nuclear as the major contributor for their power requirements. They are the masters in the technology. There is some risk of using any technology for the development. Only ensure that the benefits outweigh the risks.

In a rough estimate, about 20 to 30% of the total projects cost goes for safety related systems to ensure safe operations of nuclear reactors. Just imagine how much money is spent to save a single life? Is it justified?

See this in comparison with the figure of 1,96,000 people in India were killed in road accidents alone in 2007 (WHO figures)! Let us not oppose infra projects just for opposing or for political gains.

Environmental clearance for Jaitapur Site

For the proposed ambitious power projects which are being planed at Jaitapur, Maharashtra to generate around 33,000 MW of power mix (nuclear share is 9,900 MW), green nod has come from the Ministry of Environment, Indian government. The ministry has stipulated conditions to ensure preservation of the ecologically sensitive Western Ghats. All other new power plants coming up in the coastal area coal-based and burning of the fusil fuel is going to generate Greenhouse gases such as carbon dioxide. Locally, the temperatures in the water body is also going to rise unless a good heat/hot water recycling system is thought about, and discharges from the plants are well-controlled by the authorities.

It is stated that the nuclear power plants are environmental friendly and with enforcement of strict regulation can be the ideal choice for production of “clean” electricity. In view of this, why not the Jaitapur site is kept reserved for only nuclear power rather than mixing the coal-based plants with nuclear plants at the same site?

IAEA Board of Governors Elects New Chairman

The IAEA Board of Governors has elected Mr. Ansar Parvez, as its Chairman for 2010-2011 (one year mandate) at Vienna. Mr. Parvez is also serving as the Chairman of the Pakistan Atomic Energy Commission.

The Ambassadors and Resident Representatives of Denmark and Ukraine were also elected as Vice-Chairmen. They are Mr. John Hartmann Bernhard, Governor for Denmark, and Ms. Olena Mykolaichuk, Governor for Ukraine.

Eleven countries were elected last week to serve on the 35-member IAEA Board of Governors for the two-year period 2010-2012. The action was taken by Member States meeting at the IAEA General Conference in Vienna. The newly elected Board members are Belgium, the Czech Republic, Chile, Ecuador, Italy, Jordan, Niger, Portugal, Singapore, Tunisia and the United Arab Emirates.

Other Member States represented on the IAEA Board during 2010-2011 are Argentina, Australia, Azerbaijan, Cameroon, Canada, China, Denmark, France, Germany, India, Japan, Kenya, the Republic of Korea, Mongolia, the Netherlands, Pakistan, Peru, Russian Federation, South Africa, Ukraine, the UK, the USA and Venezuela (IAEA News).