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India-based Neutrino Observatory (INO)

Published: 22nd Nov, 2018

The National Green Tribunal (NGT) has recently upheld the environmental clearance granted to the India-based Neutrino Observatory (INO), a major research facility proposed in Theni district of Tamil Nadu.



  • The National Green Tribunal (NGT) has recently upheld the environmental clearance granted to the India-based Neutrino Observatory (INO), a major research facility proposed in Theni district of Tamil Nadu.
  • The decision has removed all current legal hurdles in building the facility, but there are still other obstacles to be overcome before work can begin on this project, which has been in planning since 2001.


  • Neutrino Observatory (INO) Project is a multi-institutional effort aimed at building a world-class underground laboratory with a rock cover of approximately 1200 meter.
  • Once built, INO would be the biggest research facility in India conducting basic research on the elementary particle called neutrino. It will be located nearly 1.5 km below the Earth’s surface, where a giant neutrino detector is to be placed.
  • The underground laboratory, consisting of a large cavern of size 132m × 26m × 20m and several smaller caverns, will be accessed by a 1900 m long and 7.5 m wide tunnel.
  • INO project is jointly supported by Department of Atomic Energy (DAE) and Department of Science & Technology (DST) with DAE also acting as the nodal agency.
  • Presently, 21 research institutes, universities and IITs are involved in this project.



  • It has a tiny mass, no charge and half spin. It interacts weakly with other matter particles.This interaction is so weak that every second trillions of neutrinos fall on us and pass through our bodies unnoticed.
  • Predicted in 1931, neutrinos were detected for the first time in 1959, and now considered to be the second most abundant particle in the universe — after the photon, or light particle.
  • The Sun, and all other stars, produce neutrinos copiously due to nuclear fusion and decay processes within their core. As they rarely interact, these neutrinos pass through the Sun, and even the Earth, unhindered.
  • Other natural sources of neutrinos are exploding stars (supernovae), relic neutrinos (from the birth of the universe), natural radioactivity, and cosmic ray interactions in the atmosphere of the Earth. These can also be produced in the lab.
  • Neutrinos are of three types – electron neutrino, tau neutrino and muon neutrino. They can change from one type to another as they travel. This process is called neutrino oscillation and is an unusual quantum phenomenon.
  • The India-based Neutrino Observatory (INO) will study atmospheric neutrinos only.
  • Nobel prize has been awarded for research on neutrinos in 1988, 1995, 2002 and 2015.

Why detect Neutrinos?

  • Neutrinos hold the key to several fundamental questions on the origin of the Universe and the energy production in stars.
  • It is by far the most numerous of all the particles in the universe (other than photons of light) and so even a tiny mass for the neutrinos can enable them to have an effect on the evolution of the Universe through their gravitational effects.
  • Neutrinos are also used in the areana of neutrino tomograph of the earth (detailed investigation of the structure of the Earth) as they are the only particles capable of probing the deep interiors of the Earth.

Need for an underground facility

  • Mass of neutrino is non vanishing (non-zero everywhere) but it is difficult to detect neutrinos due to the uncertaintity of the mass of three individual neutrino types.
  • It becomes even more notoriously difficult to detect in a laboratory because of their extremely weak interaction with matter. The cosmic rays and natural radioactivity makes it almost impossible to detect them on the surface of the Earth. This is primarily why neutrino observatories are located deep inside the Earth’s surface.

One of the earliest laboratories created to detect neutrinos underground was located more than 2000 m deep at the Kolar Gold Field (KGF) mines in India. The first atmospheric neutrinos were detected at this laboratory in 1965.

There are now four major laboratories around the world:  Sudbury in Canada; Kamioka in Japan; under the Gran Sasso mountains in Italy and in Soudan mines in the USA.



  • INO is expected to galvanise interest in basic science research and provide opportunity to students across the country to pursue cutting edge research in the field of particle physics.
  • Efforts will be made to improve the infrastructure and academic standards of the surrounding schools as permitted by governing rules. Exhibitions and other similar facilities will be arranged to enhance the scientific spirit of the local youngsters, etc.
  • The construction contract of the facility will specify that local labour should be used, based on the skill levels, to the maximum extent possible.


  • Ecological threats: Using explosives to build a subterranean facility — even controlled blasts will be a threat to the fragile ecology of the Western Ghats.
  • Radiation: There is considerable danger of radiation, although particle physicists argue that the risk is negligible and these allegations arise from misconceptions in basic physics.
  • Priority: Scientific research of this kind withdraws mammoth financial amount which some argue could be used for socio-economic needs of a developing nation like India. But innovation in the field of S&T is equally essential. This can be proved by the enormous achievements 20th century has brought in on the pillars of relativity and quantum mechanics.

Challenges before INO

The project has been mired in all kinds of trouble— litigation, public protests, opposition from NGOs and political parties, besides government apathy.

  • It had to change locations once, because the nearby Mudhumalai National Park had been declared a tiger reserve during the same time.
  • Environmental clearance granted in 2011 for the second site, too, was put in abeyance by the NGT because the project was within 5 km of the Mathikettan Shola National Park in Idukki, and no application had been moved for the approval from the National Board of Wildlife.
  • Fresh environmental clearance was given in March 2018 by the Expert Appraisal Committee (EAC) of the Ministry of Environment and Forest. This was challenged in the NGT again.
  • This has resulted into delayed operation, it was originally scheduled to start in 2012. It is now unlikely to begin before 2025.
  • In 2015, Union government approved budget for the project based on cost assessments done in 2012. It is estimated that project would cost now at least 25% more.

Possible future applications of neutrino science

  • Understanding properties of the Sun: Both visible light emiting from the surface of the sun and solar nuetrinos which come from the core of the sun approximately reach at the same time on earth. Studying these neutrinos can help understand what goes on in the interior of the sun.
  • Probing early universe: The extragalactic neutrinos observed may be coming from the distant past. These inviolate messengers can give a clue about the origin of the universe and the early stages of the infant universe soon after the Big Bang and also what is made up of.
  • Medical imaging: There are many technological applications of the detectors that will be used to study them. For instance, X-ray machines, PET scans, MRI scans, etc., all came out of research into particle detectors. Hence, the INO detectors may even have applications in medical imaging. 


While apprehensions about projects like INO are understandable, they also illustrate the fact that communication between the scientific community and citizens needs to be more informed and democratic. At a time when India is battling a brain drain epidemic, doing this could give its scientific community a much-needed boost while making science accessible to the larger public. INO will also be a catalyst for improvement in academics and living standards of the citizens.

Learning Aid

Practice Question:

The India-based Neutrino Observatory (INO) promises to be the biggest research facility in India. What are the challenges before the project? Discuss its significance for India.


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