Subheading 8401 10 of the Combined Nomenclature covers nuclear reactors, which are enclosed systems in which a controlled nuclear fission reaction takes place. This subheading classifies power reactors (pressurised water PWR, boiling water BWR, pressurised heavy water PHWR), research reactors, and small modular reactors (SMR). A reactor as a complete unit includes the pressure vessel, internal structural components, and the control rod drive system. The classification does not cover separate reactor parts (subheading 8401 40) or fuel elements (subheading 8401 30). Heading 8401 falls within Section XVI, Chapter 84 of the Combined Nomenclature, covering machinery and mechanical appliances. Classification is carried out in accordance with the General Rules for the Interpretation (GRI), rules 1 and 6, taking into account the Notes to Section XVI and Chapter 84. Nuclear reactors are goods of strategic importance and are subject to special export and import control regulations under the Euratom Treaty. A Binding Tariff Information (BTI) ruling is recommended given the complexity of classifying such equipment.

Import of nuclear reactors under subheading 8401 10 into the EU is subject to strict regulatory control extending beyond standard customs procedures. The Euratom Treaty and its implementing regulations govern the trade in nuclear materials and equipment within the EU. Regulation (EU) 2021/821 on the control of exports of dual-use items lists nuclear reactors in Category 0 of Annex I, requiring an export and import licence. The importer must hold an EORI number and obtain authorisation from the national nuclear regulatory authority. Directive 2009/71/Euratom establishes the nuclear safety framework, while Directive 2013/59/Euratom sets radiation protection standards. The Machinery Regulation (EU) 2023/1230 does not apply to nuclear equipment, which is subject to separate sectoral regulations. Required import documentation includes the dual-use licence, national nuclear regulatory authorisation, complete reactor technical documentation, nuclear safety analysis, and environmental impact assessment report. Transport is governed by IAEA regulations and ADR rules for Class 7 radioactive materials.

MFN duty rates for nuclear reactors under subheading 8401 10 should be verified in the current TARIC database of the European Commission. Given the strategic nature of the goods, trade in nuclear reactors is governed primarily by non-tariff restrictions arising from nuclear safety and nuclear non-proliferation regulations. The Nuclear Non-Proliferation Treaty (NPT) and IAEA safeguards have a direct impact on trade conditions. The Nuclear Suppliers Group (NSG) establishes export control guidelines for nuclear technology, which the EU implements through the dual-use regulation. Import from countries subject to EU sanctions (Russia, Iran, North Korea) is subject to severe restrictions or an outright ban. Chapter 84 products are not subject to the CBAM mechanism (Regulation (EU) 2023/956). Preferential tariff rates under FTA agreements may be theoretically available, but in practice trade in nuclear reactors is regulated primarily by safety and non-proliferation rules. All current rates and trade measures should be verified in the European Commission's TARIC database.