The International Atomic Energy Agency (IAEA) states that the fourth pillar of international nuclear law is liability compensation.  A number of initiatives since the accident at Chernobyl in 1986 have worked to strengthen the international liability regime.  One such initiative is the Convention on Supplemental Compensation for Nuclear Damage (CSC).  This paper will summarize the objectives of the CSC created separate from the existing Vienna or Paris liability conventions. 
Opened for signature in 1997 as a free-standing instrument, the United States ratified the CSC in 2008.  The CSC went into effect in 2015 when it was ratified by Japan as the sixth party because the installed capacity of treaty members exceeded four hundred gigawatts of thermal power.  Several other nations have accepted the CSC; currently there are eleven contracting parties and another eleven signatories that have not yet ratified it.
After exploring the history of the CSC, this paper will explore its terms.  The CSC requires a State Party to accept the higher compensation amounts, including participation in an international fund, a broader definition of nuclear damage, and the updated jurisdiction rules that agree to litigate in the courts of the nation where the incident occurred.  The provisions of the CSC on these matters take precedence over any similar provisions in other nuclear liability instruments to which a Nation might adhere.  The CSC established two tiers of compensation with the first tier that specified the minimum amount that a State must make available under its national law to compensate for nuclear damage.  A second tier is provided by other parties in the event of nuclear damage that exceeds the first tier.  Each nation’s contribution varies depending on the number of operating plants in the nation at the time the second tier is called.
With that foundation, the paper will explore the benefits and drawbacks parties considering accepting the CSC face.  A global nuclear civil liability regime would promote international trade in peaceful use of nuclear technology by bringing more predictability to the market. It would also encourage improvements in civilian nuclear plant safety by helping ensure sharing of improved nuclear safety technology to all nations. Lastly, the CSC's creation of a supplementary international fund is expected to help ensure that potential victims of a civil nuclear incident overseas will be adequately compensated compared to the dismal compensation provided after the Chernobyl accident. 
Any nation considering entering or expanding its participation in commercial nuclear technology whether as a user or a supplier should weigh its options for upholding the fourth pillar of international nuclear law.  Joining the CSC is one option to weigh, and this paper will help inform that choice.