#Onthisday in 1754, the French chemist Joseph-Louis Proust was born! Though he was initially to follow in his father’s footsteps and become a pharmacist, Proust instead made significant contributions to several areas of chemistry. His most famous discovery was the “law of definite proportions”, also known as Proust’s law. Proust’s law established that the ratio of elements in chemical compounds is always the same, no matter the source. This means, for example, a molecule of uranium oxide will always consist of one atom of uranium and two atoms of oxygen, whether it’s from Canada, South Africa, or anywhere else! Before this law was understood, it was thought that elements could combine in a variety of ways. Proust’s law helped confirm John Dalton’s atomic theory, which stated that all matter is composed of atoms, and that compounds are made of elements, which always combine in the same way.

At #UNGA, IAEA Director General @rafaelmgrossi and @the_IDB President @igoldfajn signed an agreement to strengthen cooperation on the safe, secure and sustainable use of nuclear energy in Latin America and the Caribbean. The agreement, signed on September 24, will support cooperation on nuclear energy and development, including energy-system planning, technical assistance, capacity building and infrastructure. It follows recent partnerships between the IAEA and international financial institutions, including the @WorldBankGroup, @ADB_HQ, @AgendaCAF and @TheOPECFund, to help countries harness nuclear energy as an option to meet rising electricity demand. iaea.org/newscenter/pressrel…

What role could microreactors play in future energy systems? A new IAEA publication explores microreactors, a subset of small modular reactors (#SMRs), as an emerging nuclear technology to support remote or off-grid communities, industrial sites, data centres and specialized applications, including space and maritime uses. #Microreactors, which are designed to generate electrical power typically of about 10 MW(e), show promise in offering reliable, flexible, resilient and low-carbon power in environments where large scale infrastructure is unavailable, impractical or uneconomic. The new Outlook examines pathways to demonstration, deployment and commercialization of microreactors together with opportunities and challenges, and highlights the IAEA’s support through international cooperation, knowledge exchange and flagship initiatives, including the SMR Platform and the Nuclear Harmonization and Standardization Initiative. This publication is based on data from the IAEA Advanced Reactors Information System (ARIS) database, microreactor designers and publicly available sources. Read it here doi.org/10.61092/iaea.knfn-4… #NuclearEnergy

The ZNPP has adjusted the operating strategy for its emergency diesel generators (EDGs) as diesel fuel supplies at the site continue to decline, Director General @RafaelMGrossi said today. Currently the plant is receiving off-site power through its sole remaining power line, the 330 kilovolt (kV) Ferosplavna-1 line. However, repeated losses of this connection in recent months have underlined the importance of the site’s EDGs. With diesel fuel reserves running low, the plant has taken steps to reduce fuel consumption in the event of another loss of external power.  iaea.org/newscenter/pressrel…

Addressing the growing burden of cancer and global disparities in cancer diagnosis and treatment requires innovative, multi-sectoral solutions that go beyond traditional partnerships. On the margins of the 70th IAEA General Conference, the IAEA signed agreements with six private sector partners to advance comprehensive access to radiation medicine and help bridge the global gap in cancer care. Read more: atoms.iaea.org/4hmWxZb #IAEAGC

The IAEA invites experts worldwide to submit abstracts for its 2027 symposium on the future of radiopharmaceuticals. Radiochemists, radiopharmacists, biologists, physicists, technologists, medical researchers, decision makers, health regulators, academics and other professionals in the field are invited to submit abstracts for the International Symposium on Trends in Radiopharmaceuticals (ISTR-2027), to be held at IAEA Headquarters in Vienna, Austria, from 21 to 25 June 2027. Find out more: atoms.iaea.org/47gVEwk #ISTR2027

Registration and abstract submission are OPEN for the 2nd IAEA NEXSHARE Workshop on Experimental Testing and Validation for Design and Safety Analysis Computer Codes for Advanced Reactors and Small Modular Reactors! This workshop will bring together experts from industry, regulators, technical support organisations, universities, research institutes, and more. It will cover challenges in code usage and validation, updates on experimental and code validation programmes, and key lessons learned. 🗓️ 30 November - 4 December 📍 Vienna International Centre ⏳ Deadline: 16 October Participation will include attendance to the International Symposium on Nuclear Energy Research and Development held at IAEA Headquarters from 1 - 2 December 2026. Scan the QR or register here: atoms.iaea.org/4gtujvb

The IAEA has been informed of numerous drone and other military strikes in the vicinity of the Zaporizhzhya Nuclear Power Plant in recent weeks, causing several casualties and potentially threatening nuclear safety. The reported incidents earlier this month included drone attacks on the plant’s off-site training centre as well as strikes on diesel fuel transports for its emergency generators. Other attacks reportedly hit locations in the nearby city of Enerhodar, where many plant staff live. IAEA DG @rafaelmgrossi expresses deep concern about the reported incidents, which underline constant dangers to nuclear safety during the conflict, as well as to plant staff and their families. All attacks on or near NPPs are unacceptable and must stop immediately, DG Grossi says.

The 70th annual IAEA General Conference came to a close on Friday last week, following five days of discussions, events and activities related to a range of nuclear topics. Resolutions and decisions adopted at the Conference will guide the IAEA’s activities in the coming year. Read more: atoms.iaea.org/4y5VovY #IAEAGC

Check out the latest issue of the IAEA Bulletin on #RaysOfHope It features stories on: 🟦Anchor Centres making cancer care sustainable 🟦Nuclear technologies shaping the future of cancer care 🟦Radiopharmaceutical innovation and much more Find out how nuclear science and technology are making a difference in cancer care atoms.iaea.org/4j6PlCK #IAEAGC

After five days of dialogue, events and interactions, the 70th IAEA General Conference has come to a close. With over 3600+ participants, this year’s #IAEAGC was the biggest ever. This year’s conference also featured the #ScientificForum, where ‘Rays of Hope’ took centre stage. Thank you for joining us for the biggest week in nuclear. See you at the 71st #IAEAGC next year!

#IAEAGC Eleven countries have been newly elected to serve on the 35-member IAEA Board of Governors for the 2026–2028 period. The election took place on Thursday 17 September, at the plenary session of the 70th IAEA General Conference. Learn more about new IAEA Board of Governors elected countries atoms.iaea.org/4xzuonL

The IAEA has been informed that the cooling tower of a reactor unit of the Kursk Nuclear Power Plant in the Russian Federation was hit by a drone early on Thursday. It was reported that the unit was operating at the time, but its operating mode did not change and there was no fire. DG @rafaelmgrossi says all attacks on nuclear facilities are unacceptable as they could endanger nuclear safety and security, irrespective of where they occur. DG Grossi also reiterates call for maximum military restraint to prevent the risk of a nuclear accident.

It’s the final day of the 70th IAEA General Conference! Wrap up your #IAEAGC week with our last set of side events and tours. See the full list here: atoms.iaea.org/GC70 #ScientificForum #IAEAGC

Director General @rafaelmgrossi this week told IAEA Member States that the nuclear safety and security situation in Ukraine remains highly fragile, as Agency teams stationed at nuclear facilities across the country continue to report frequent air raid alarms and military activity. atoms.iaea.org/4ybHjxd

Making nuclear science accessible One year ago, the IAEA Visitor Centre in Seibersdorf, Austria, was inaugurated. Welcoming visitors from around the world to discover how nuclear science and technology contribute to areas such as human health, food and agriculture, industry, cancer care , food safety, or energy production and environmental protection, the Centre is becoming a growing hub for education and outreach. Through 33 interactive exhibits and guided tours, the Centre demonstrates how nuclear science helps address global challenges by turning complex scientific concepts into engaging experiences. Read more: atoms.iaea.org/4dBVHq7

The IAEA is pleased to announce that Italy is establishing a Member State Support Programme with the Agency. Through this programme, Italy will make a significant contribution towards the IAEA’s efforts to enhance its nuclear verification capabilities in support of effective and efficient nuclear #safeguards.

📢 We are hiring! Check all positions that are closing soon and apply before the deadline 📷 iaea.org/employment #UNjobs #IAEAjobs

Day 4 of #IAEAGC Don't miss out on the 100+ side events, guided tours and visits hosted by the IAEA, member countries and organizations. See the full list: atoms.iaea.org/GC70Wednesday