Convention on Supplementary Compensation / CSC meaning

In legal practice, the Convention on Supplementary Compensation for Nuclear Damage (CSC) describes a global nuclear third‑party liability regime that supplements national compensation for nuclear damage through an international fund. It is an iaea treaty adopted on 12 September 1997 and in force since 15 April 2015, following Japan’s approval, which took the combined installed nuclear capacity of Contracting Parties over the 400,000‑unit threshold. Key features include strict, exclusive channelling of liability to the nuclear operator, compulsory financial security/insurance, a minimum national compensation level of 300 million SDR, and a supplementary tier funded by Contracting Parties (assessed by installed capacity and the UN scale) to meet cross‑border claims. Jurisdiction lies with the courts of the Installation State, with recognition/enforcement provisions and specified limitation periods. Contracting Parties include, among others, Argentina, Canada, Ghana, India, Japan, Montenegro, Morocco, Romania, the United Arab Emirates and the United States. UK relevance: the UK is not a CSC party and applies the Paris and Brussels Conventions via the Nuclear Installations Act 1965 (as amended); Ireland is also not a CSC party. The term is treaty‑based rather than defined in UK or Irish statute, and is most relevant to cross‑border projects, insurance placement and claims strategy involving CSC jurisdictions.