Maarg Manthan · Topic 13.11

Nuclear and Radiological Disasters

Science & Technology › Nuclear Technology and Energy · Topic 13.11

A nuclear or radiological disaster is an emergency in which radioactive material is released into the environment and harms people, animals or property. Causes include accidents at nuclear power plants, accidents in the handling of radioactive sources in hospitals and industry, loss or theft of sources, transport accidents, and deliberate acts such as attacks on nuclear facilities or the use of a radiological dispersal device, also called a dirty bomb, which spreads radioactive material with conventional explosives. The worst power plant accidents so far, rated level 7 on the International Nuclear and Radiological Event Scale, were Chernobyl in Ukraine in 1986 and Fukushima Daiichi in Japan in 2011. In India, the National Disaster Management Authority issued guidelines on the management of nuclear and radiological emergencies in 2009.

5 min read · UPSC Prelims · Science & Technology · Nuclear Technology and Energy

At a Glance

Level 7 accidents Chernobyl 1986, Fukushima 2011
Level 5 accident Three Mile Island, 1979
Dirty bomb Radiological dispersal device
Indian guidelines NDMA, 2009
Protection Time, distance, shelter, iodine
Exam link UPSC Prelims, Science & Technology: Nuclear Technology and Energy

Where Does It Fit?

This is the last topic of the macro on nuclear technology and energy. It covers the risk side of nuclear technology and the way in which countries prepare to respond to nuclear and radiological emergencies. Previous topic: Radioactive Waste and Nuclear Waste Management. Next topic: Regulatory Bodies for ICT in India (Ministry of Communications and IT).

Which Major Accidents Have Occurred?

Event	Details
Windscale (UK), 1957	A fire in a graphite reactor released radioactive iodine. INES level 5
Kyshtym (USSR), 1957	Explosion of a waste tank released radioactivity. INES level 6
Three Mile Island (USA), 1979	Partial core meltdown after cooling failure and operator errors. INES level 5. Little radiation outside the plant
Chernobyl (Ukraine), 26 April 1986	Explosion and fire in a reactor during a test, with large release of radioactivity over Europe. INES level 7. Led to evacuation of about 350,000 people and an exclusion zone
Fukushima Daiichi (Japan), 11 March 2011	An earthquake and tsunami cut power and cooling, causing meltdowns in three reactors. INES level 7. Led to evacuation of over 100,000 people
Goiania (Brazil), 1987	Scavengers opened an abandoned caesium-137 radiotherapy source, killing four and contaminating many people. A radiological accident
Mayapuri (India), 2010	A cobalt-60 source in scrap sold from a Delhi University laboratory caused radiation injury and one death in Delhi

How Do Countries Prepare and Respond?

Emergency planning zones: areas around plants for evacuation and sheltering
Protective actions: sheltering indoors, evacuation, taking potassium iodide tablets to protect the thyroid, controlling food and water
Potassium iodide: blocks uptake of radioactive iodine by the thyroid if taken in time
Decontamination: removing contaminated clothing and washing skin
Monitoring: radiation detectors and aerial surveys to map contamination
NDMA guidelines 2009: give roles for central and state authorities, the Department of Atomic Energy, NDRF, medical teams and armed forces in nuclear and radiological emergencies
NDRF: the National Disaster Response Force has special battalions trained for chemical, biological, radiological and nuclear emergencies
Crisis Management Group: the Department of Atomic Energy has an emergency response system and a crisis management plan

What Else Should You Remember?

Radiological dispersal device: a dirty bomb contaminates an area with radioactive material but is much less destructive than a nuclear bomb, and its main effects are fear and the cost of cleanup
Security of sources: international codes on security of radioactive sources and the Convention on the Physical Protection of Nuclear Material
International conventions: India is party to the Convention on Early Notification of a Nuclear Accident and the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency, 1986
IAEA role: the International Atomic Energy Agency helps countries with emergency preparedness and runs the Incident and Emergency Centre
Long term effects: increased cancer risk, thyroid cancer in exposed children after Chernobyl, mental health and displacement
Mock drills: periodic exercises at plants test preparedness, with the participation of district administration
Safety culture: design, training and regulation are the best protection, as in Atomic Energy Regulatory Board (AERB) and Safety Standards in Nuclear Plants
India’s record: India has not had a major off-site release from its plants, but has had incidents, such as a fire at Narora in 1993 and a leak at Kakrapar in 1994
Radiological accidents: most accidents involve lost sources, as in Goiania and Mayapuri, so source tracking and scrap control matter
Nuclear war: nuclear weapons produce blast, heat and fallout, and civil defence planning is separate from plant emergency plans
Lessons from Fukushima: protect backup power, plan for multiple failures, and prepare for natural hazards
Link: radiation basics are in Radiation and Radioactivity

Why Does It Matter for the Exam?

Accidents and levels: Chernobyl, Fukushima, Three Mile Island
Terms: dirty bomb and RDD
Preparedness: NDMA 2009 and NDRF
Current affairs link: nuclear plant safety near conflict zones
Common errors: confusing a dirty bomb with a nuclear weapon or giving wrong year for Chernobyl

As an analytical point, nuclear accidents are rare but severe, so preparedness must be built before they occur. Strong regulation, security of radioactive sources and regular drills limit the harm.

Why Is This Topic Important?

Cases Chernobyl, Fukushima
Preparedness NDMA, NDRF
Threat Dirty bomb

What Came Next?

The next macro covers information technology, telecommunications and computers. Next topic: Regulatory Bodies for ICT in India (Ministry of Communications and IT).

Key People and Terms

INES Nuclear event scale
RDD Radiological dispersal device
Meltdown Overheated and damaged reactor core
Exclusion zone Area closed to public
KI Potassium iodide
CBRN Chemical, biological, radiological, nuclear

Exam Corner

Points to Remember

Chernobyl: 26 April 1986, level 7.
Fukushima: 11 March 2011, level 7.
Three Mile Island: 1979, level 5.
NDMA nuclear guidelines: 2009.
Mayapuri incident: 2010, Delhi.

Do Not Confuse With

Dirty bomb and nuclear bomb Spreads radioactive material versus nuclear explosion
Nuclear accident and radiological accident Reactor event versus source mishandling
Sheltering and evacuation Staying indoors versus moving away

Memory Hook

Three Mile Island five, Chernobyl and Fukushima seven; shelter, iodine, and know your source.

Mains Angle

Questions ask for accident facts and preparedness. These points help.

Risks Plants and sources
Response NDMA and NDRF
Lessons Prevention

A Question You May Face

An original practice question, not a past paper question.

“Discuss the nature of nuclear and radiological disasters and evaluate India’s preparedness to deal with them.”

How to Answer

Types Plants and sources.
Cases Chernobyl, Fukushima, Mayapuri.
Response NDMA, NDRF.
Way Drills, source control.

GS Relevance

Prelims: major accidents, INES levels, dirty bomb, NDMA guidelines. GS Paper 3: disaster management, nuclear safety, internal security.

Frequently Asked Questions

What is a radiological emergency?

A radiological emergency is an event in which radioactive material is released or an uncontrolled radiation source exposes people or the environment to radiation. It can arise from a nuclear power plant accident, loss or theft of a radioactive source, a transport accident, or a deliberate act such as a dirty bomb.

What was the Chernobyl disaster?

The Chernobyl disaster occurred on 26 April 1986 at the nuclear power plant in Ukraine, then in the Soviet Union, when a reactor exploded and burned during a test. It released large amounts of radioactivity across Europe, led to evacuation of about 350,000 people and an exclusion zone, and is rated level 7.

What happened at Fukushima in 2011?

On 11 March 2011 a powerful earthquake and tsunami struck Japan and cut off power and cooling at the Fukushima Daiichi plant, causing meltdowns in three reactors and release of radioactivity. More than 100,000 people were evacuated. It is rated level 7 and led countries, including India, to review safety of their plants.

What is a dirty bomb?

A dirty bomb, or radiological dispersal device, is a conventional explosive combined with radioactive material that is spread when it explodes. It is not a nuclear weapon and causes far less destruction, but it can contaminate an area, force evacuation, and cause fear and expensive clean-up. Security of radioactive sources is the main defence.

How is India prepared for nuclear emergencies?

India has the National Disaster Management Authority guidelines of 2009 on nuclear and radiological emergencies, a crisis management plan of the Department of Atomic Energy, emergency plans around plants with periodic drills, and National Disaster Response Force battalions trained for radiological and nuclear emergencies, with radiation monitoring and medical support.

PYQ Practice — Statement Analysis

1 The Chernobyl accident occurred in 1986.

True

INES level 7.

2 A dirty bomb is the same as a nuclear weapon.

False

It spreads radioactive material with conventional explosives.

3 Potassium iodide protects the thyroid against radioactive iodine.