India has ratified the International Atomic Energy Agency (IAEA) Convention on Supplementary Compensation for Nuclear Damage (CSC), which it signed in 2010. The CSC relates to liability and compensation in the event of a nuclear incident. The instrument of ratification has been deposited with the agency’s deputy director-general and head of the nuclear safety and security department, Juan Carlos Lentijo. The convention comes into force for India on 4 May.

India’s external affairs ministry said the ratification marked "a conclusive step in addressing issues related to civil nuclear liability in India", as the country steps up talks with international reactor supplies towards expanding its civil nuclear programme. Towards the end of 2015, India and Japan started the "final stages" of negotiations towards signing a civil nuclear cooperation deal and in January the Nuclear Power Corporation of India Limited signed a cooperation agreement with France’s EDF Group for the proposed construction of up to six European pressurised water reactor (EPR) units at Jaitapur, in Maharashtra state. Talks with the US are continuing. However, all these projects have been delayed because of concerns about liability. Only Russia was undeterred by the liability issue and has built two reactors at Kudanakulam NPP with two more planned and others to follow.

India’s nuclear liability regime has provided a stumbling block for would-be suppliers. In most countries nuclear plant operators are liable for any damage caused in the event of an accident, against which they take out liability insurance ,but up until 2010 – when the Indian government passed its Civil Liability for Nuclear Damage Act – India had been a notable exception, with reactor suppliers potentially liable for damages in the event of an accident. The 2010 legislation makes Indian operators primarily liable for any nuclear accident, but still keeps open the possibility of recourse to suppliers.

In addition to India, five other states have signed and ratified the CSC – Argentina, Morocco, Romania, the United Arab Emirates and the US. A total of The CSC aims to increase the amount of compensation available in the event of a nuclear incident through public funds made available by its contracting parties on the basis of their installed nuclear capacity and United Nations rate of assessment. It also aims to establish treaty relations among states whether or not they belong to the existing nuclear liability conventions, notably the Vienna Convention on Civil Liability for Nuclear Damage, which came into force in 1977, and the Paris Convention on Third Party Liability in the Field of Nuclear Energy, which came into force in 1968. The Vienna and Paris conventions, which have both since been amended, were linked by a joint protocol in 1988.

The CSC was adopted in 1997 but could only enter into force after it had been ratified by five states with a minimum of 400GW (thermal) of installed nuclear capacity. Japan became the fifth such state to ratify the convention in January 2015, and it entered into force 90 days later.