The licensing of SMRs will be affected by the Fukushima accident in the same way as for large reactors. Regarding licensing status and regulatory issues relevant to SMRs, the analysis of recent publications leads to the following observations:

• All of the advanced SMRs addressed in the present study have been designed or are being designed in compliance with current national regulations.

• SMRs available for deployment, which are the CANDU-6, PHWR, QP-300, CNNP-600, and the KLT-40S, have already passed the licensing procedures in the countries of origin, which is a confirmation of their compliance with the national regulations. The CANDU-6 and the QP-300 have been deployed in countries other than the country of origin, which means they have also been licensed in those countries.

• Regarding advanced SMR designs, three of them are in a formal licensing process in Argentina (CAREM-25), China (HTR-PM) and the Republic of Korea (SMART), and several others are in pre-licensing negotiations in the United States (NuScale, mPower, Westinghouse SMR, New Hyperion Power Module) and India (AHWR).

Regulatory issues and delays regarding advanced SMR licensing may be observed due to the following main reasons:

• Some advanced water cooled SMR design concepts incorporate novel technical features and components targeting reduced design and operation and maintenance complexity which need to be justified by the designers and accepted by the regulators. Regulatory provisions for such an acceptance may be not readily available. [84]

• Some of the advanced SMR design concepts provide for a long-life reactor core operation in a “no on-site refuelling mode”. The regulatory norms providing for justification of safety in such operation modes may be not readily available in national regulations.

A governmental programme to support licensing of selected advanced SMRs could help overcome the delays due the above mentioned and other reasons.