Category: Clauses & wordings · Reviewed by Taylor Watts, Broker · New Business · Last reviewed June 2026
A standard clause excluding loss, damage, cost or liability caused by, contributed to by, or arising from ionising radiation, radioactive contamination, nuclear fuel, nuclear waste, or nuclear assemblies, reflecting the channelling of nuclear liability to licensed site operators under UK statute.
The nuclear exclusion (often called the “radioactive contamination” or “nuclear energy risks” exclusion) is one of the oldest and most universal exclusions in the global insurance market. It removes cover for loss or damage caused by ionising radiations or contamination by radioactivity from any nuclear fuel or from any nuclear waste from the combustion of nuclear fuel, and for loss arising from the radioactive, toxic, explosive or other hazardous properties of any explosive nuclear assembly or nuclear component thereof.
The clause originated in the 1950s following the commercial development of nuclear power. The London market’s view, codified in NMA1622 (nuclear/chemical/biological terrorism exclusion is a later companion), was that nuclear risks were uninsurable on a conventional basis because of their catastrophic potential, the difficulty of pricing low-frequency/high-severity events, and the international legal framework channelling liability exclusively to nuclear site operators. Cover for the operators themselves is provided by Nuclear Risk Insurers Limited (NRI), the UK mutual pool that succeeded the British Insurance (Atomic Energy) Committee, and reinsured by similar national pools worldwide.
The exclusion applies regardless of any other cause or event contributing concurrently or in any sequence to the loss — language designed to preclude arguments that a non-nuclear concurrent cause should save the claim. It is found in property, marine, aviation, motor, engineering, liability and many specialty wordings.
For most UK commercial insureds, the practical effect is that nuclear-triggered losses are uninsured under standard policies. Cover is available only through the nuclear pool or by purchasing dedicated nuclear cover from specialist markets. Carve-outs exist for small quantities of radioactive material used in medical, industrial or research applications (typically under a “radioactive isotopes” write-back).
The UK statutory framework rests on the Nuclear Installations Act 1965, which implements the Paris Convention 1960 and the Brussels Supplementary Convention 1963 (as amended by the 2004 Protocols, brought into force in the UK in 2016 by the Nuclear Installations (Liability for Damage) Order 2016). Section 7 of the 1965 Act imposes strict, exclusive liability on licensed site operators for any occurrence on the site involving nuclear matter that causes injury to any person or damage to property. Section 12 provides that no other person is liable in respect of an occurrence to which section 7 applies — the principle of “channelling” of liability to the operator.
The operator’s liability is capped (currently EUR 1.2 billion under the 2004 Protocols, with state cover above that level up to EUR 1.5 billion and supplementary international funds above that). The Nuclear Decommissioning Authority and individual operators (EDF Energy, Sellafield Ltd, Magnox Ltd, etc.) carry insurance through Nuclear Risk Insurers.
Because section 12 channels liability exclusively to the operator, third-party insurers writing general liability cover need not (and should not) provide indemnity for nuclear incidents at licensed sites — the legal liability simply does not attach to their insured. The exclusion reflects and reinforces this statutory scheme.
The Energy Act 2013 and the Nuclear Safeguards Act 2018 (post-Brexit) provide the wider regulatory framework. The Office for Nuclear Regulation (ONR) is the safety regulator under the Energy Act 2013.
Market wordings include NMA1622 (Nuclear Energy Risks Exclusion), NMA1975A and NMA1976A (radioactive contamination and explosive nuclear assemblies), and the LMA5218 series for property risks. Marine wordings rely on the Institute Radioactive Contamination, Chemical, Biological, Bio-chemical and Electromagnetic Weapons Exclusion Clause (CL.370).
The exclusion is rarely tested in UK litigation because the statutory channelling makes nuclear claims against ordinary commercial insurers commercially and legally unviable. The exclusion does, however, generate practical issues at the margins.
Small-quantity radioactive material: Hospitals, universities and industrial users handle radioactive isotopes for diagnostic, therapeutic or research purposes (e.g., technetium-99m, iodine-131, americium-241 in smoke detectors and density gauges). A blanket nuclear exclusion would defeat cover for fire damage to a hospital incidentally involving such material. Most wordings include a radioactive isotopes write-back permitting cover for “naturally occurring or artificially produced radioactive isotopes (other than nuclear fuel) when such isotopes are being prepared, carried, stored or used for commercial, agricultural, medical, scientific or other similar peaceful purposes.”
Transport of nuclear materials: Carriage of irradiated fuel by road, rail or sea is governed by the Carriage of Dangerous Goods Regulations 2009 and the IAEA Transport Regulations. Liability during transit is channelled to either the consignor or consignee operator depending on the journey leg. Carriers’ liability insurance excludes nuclear matter, with cover provided by the nuclear pool.
Marine and aviation: The CL.370 RACE clause excludes radioactive, chemical, biological and electromagnetic weapons in a unified clause. The CL.380 cyber attack exclusion sits alongside as a separate exclusion.
Concurrent causation: The exclusion’s “regardless of any other cause” wording is intended to defeat any argument that a concurrent non-nuclear cause should save the claim. The Wayne Tank principle (Wayne Tank & Pump Co Ltd v Employers Liability Assurance Corp [1974] QB 57) — that a concurrent excluded cause defeats cover — supports this outcome even without the explicit wording, but the explicit drafting puts the matter beyond doubt.
Dirty bombs and CBRN terrorism: A radiological dispersal device (“dirty bomb”) would engage both the terrorism and nuclear exclusions. Pool Re cover historically excluded CBRN attacks; some scheme variants now write CBRN back for member insurers. Brokers should check policy wording carefully where clients have exposures to CBRN risk (e.g., critical national infrastructure, large public venues).
Disclosure under ICOBS 6.1 is important: the catastrophic nature of nuclear risks means brokers should ensure clients are aware that nuclear-triggered losses fall outside standard cover, particularly for clients near licensed nuclear sites or in industries handling radioactive materials.
A pharmaceutical research facility in Cheshire holds a commercial combined policy with the standard NMA1622 nuclear exclusion and a radioactive isotopes write-back permitting cover for isotopes used in research. A fire breaks out in a laboratory storing sealed sources of caesium-137 and americium-241 used in calibration of radiation detection equipment. The fire damages the laboratory and ruptures the source containment, causing localised radioactive contamination. Clean-up costs are GBP 380,000 (specialist decontamination) and property damage GBP 220,000.
The insurer’s loss adjuster considers two issues. First, does the radioactive isotopes write-back apply? The sealed sources are clearly within the write-back wording — they are artificially produced isotopes used for peaceful (research) purposes. Second, are the decontamination costs covered? The policy covers physical damage to insured property and reasonable costs of debris removal and clean-up; the specialist nature of radiological clean-up is recoverable subject to the policy limit.
The claim is admitted for GBP 600,000 subject to the GBP 5,000 deductible. The Environment Agency is notified under the Environmental Permitting (England and Wales) Regulations 2016, and the Office for Nuclear Regulation is informed under the Radiation (Emergency Preparedness and Public Information) Regulations 2019.
If the source had been nuclear fuel rather than a small isotope, the radioactive isotopes write-back would not have applied and the NMA1622 exclusion would have defeated cover. The insured would have needed dedicated cover through Nuclear Risk Insurers or a specialist nuclear pool.
By Matt Bartlett, Director, on 2026-06-11. Next review: 2026-12-11.
SEO meta: - Title: Nuclear exclusion | UK Insurance Wiki | Apex Insurance Brokers - Slug: /wiki/nuclear-exclusion/ - Schema: DefinedTerm + Article + BreadcrumbList
This entry is part of the Apex Insurance Wiki. Last reviewed by Matt Bartlett on 2026-06-11. Apex Insurance Brokers Limited, FCA FRN 724952, Companies House 07014570. Not regulated advice — consult your broker on your specific position.
Apex Insurance Brokers serves UK professional services firms and commercial businesses. Call 0117 325 0027, email hello@apexinsurancebrokers.co.uk, or request a quotation.
Get a quote