The Western European Nuclear Regulators Association (WENRA) is an association of heads of nuclear regulatory authorities of countries operating, or having recently operated, nuclear power plants in Europe. It is voluntary and informal — there is no treaty basis — but its harmonised reference levels are influential in shaping national rule revisions.

Origin and membership

WENRA was established in 1999 as an "association of heads of nuclear regulators" with the original purpose of giving European regulators a common forum during EU enlargement and on accession candidates' nuclear safety. Membership today covers regulators from countries operating commercial reactors (France, UK, Spain, Sweden, Finland, Belgium, Netherlands, Bulgaria, Czech Republic, Germany while reactors operated, Hungary, Romania, Slovakia, Slovenia, Switzerland, Ukraine) plus regulators of countries with phased-out fleets or research reactors. Several non-EU regulators participate.

Working groups and outputs

WENRA's technical work is carried out by three Working Groups:

  • RHWG — Reactor Harmonization Working Group. Produces and maintains the Reactor Reference Levels (RLs) for operating reactors, plus "Safety Objectives for New Nuclear Power Plants".
  • WGWD — Working Group on Waste and Decommissioning. Reference levels for radioactive waste management and decommissioning facilities.
  • IRMG — Inspection Working Group, on harmonisation of inspection practice.

The Reactor Reference Levels are organised in "Issues" (Issue A safety policy, Issue B operating organisation, Issue C management system, etc.). Member regulators commit to implementing the RLs in national regulation within an agreed timetable and to report progress.

Influence on national rules

WENRA reference levels do not have direct legal force. They take effect when individual member regulators amend their national rules to bring them into line — for example, the Swedish SSMFS 2021:4 on reactor design and SSMFS 2021:6 on operation were drafted with the WENRA reference levels in mind. Similar patterns hold in France (ASN), Finland (STUK YVL), and the UK (ONR SAPs/TAGs).

After Fukushima Daiichi, WENRA contributed to the EU "stress tests" framework (ENSREG, 2011-2012) and updated the Safety Objectives for New NPPs to require essentially zero off-site releases that would necessitate long-term protective actions.

Relationship to other bodies

WENRA cooperates with the IAEA and the OECD NEA and feeds technical input into ENSREG (the European Nuclear Safety Regulators Group, the EU-level body composed of regulator heads and the Commission). WENRA reference-level methodology is often used as the technical backbone behind EU directives on nuclear safety and on waste.