An amendment to the 1987 Convention on the Physical Protection of Nuclear Materials (CPPNM) entered into force on 8 May. The CPPNM was first adopted by states in 2005, but it took more than 10 years for it to secure the adherence of two-thirds of states needed for it to become legally binding. That was achieved on 8 April when Nicaragua became the 102nd state to adhere to the amendment. There are currently 152 parties to the CPPNM.

The CPPNM covers the physical protection of nuclear materials used for peaceful purposes during international transport. The amendment broadens its scope to cover the protection of nuclear facilities or nuclear material in domestic use, storage and transport, and makes it legally binding for states to establish, implement and maintain an appropriate physical protection regime applicable to nuclear material and nuclear facilities under their jurisdiction.

IAEA director general Yukiya Amano said: "The Agency has worked hard, in particular in the last few years, to encourage countries to adhere to the amendment … Our collective efforts have now paid off. The world will be a safer place as a result." Under the amendment, countries are required to establish appropriate physical protection regimes for nuclear material. They also take on new obligations to share information on sabotage and credible threats of sabotage.

However, there are 50 parties to the CPPNM that have not adhered to the amendment. "I continue to urge all states to adhere to this important legal instrument," said Amano. "Universal implementation of the amended convention will help to ensure that nuclear material throughout the world is properly protected against malicious acts by terrorists."

"While some countries have already made legislative changes, the new international notification and cooperation requirements will only become fully operational now that the amendment has entered into force," the IAEA said. The amount of nuclear material in peaceful use around the world has grown by 70% since 1999 and "will continue to grow in the coming decades as global use of nuclear power increases", the IAEA said. Almost 2800 incidents involving radioactive material "getting out of regulatory control" have been reported to the agency by member states since 1995. Only a few of these cases involved material that could be used to make a nuclear explosive device, although some could be used with conventional explosives to make a ‘dirty bomb’, it added.