Radiological protection during decommissioning – the WGDECOM working group holds its 14th meeting

RP-HANS DECOM workshop SB - team

The ISOE Working Group on Radiological Protection Aspects of Decommissioning Activities at Nuclear Power Plants (WGDECOM) held its 14th meeting on 10-13 October in Mechelen, Belgium. The event was hosted by ENGIE Electrabel (a Belgian energy corporation) and supported by the Federal Agency for Nuclear Control (FANC).

Established in 2014, the WGDECOM unites 19 experts from 12 countries in developing a process to better share radiological protection data and experience for nuclear power plants that are in decommissioning or being prepared for decommissioning. Since its first briefing in 2015, the WGDECOM meetings have included technical visits to decommissioning sites in the United States, Sweden, Spain, Switzerland, France and then Germany.

The 2023 meeting in Belgium was composed of four major components. The first was a technical visit to the Doel Nuclear Power Plant. This included presentations on ENGIE nuclear power plant fleet decommissioning, its declassification of sites, FANC’s position papers, the high-level fleet decommissioning clearance strategy, and the chemical system decontamination (CSD) at Doel 3. A walk-through of the Doel 3 decommissioning site included the reactor building, reactor pool, steam generators, primary pumps and safety injection tank. Participants were brought to see the room where the Automated Mobile Decontamination Appliance (AMDA) was installed, the synoptic command cabinet for the CSD resin tanks, the turbine hall, which will be reconverted into a container storage place for contaminated components coming from dismantling; and the construction site of a new building for storage of contaminated operational materials.

RP-HANS DECOM workshop SB - team1 

The second part of the meeting was a technical visit of the Belgian Nuclear Research Centre (SCK·CEN). Presentations were given on the role of health physics control in decommissioning, the Belgian Reactor 3 (BR3) decommissioning project, the characterisation of the BR3 biological shield, conditional clearance of aluminum hydroxide from Doel 1 and 2, and the development of a Radiological Impact Assessment Demonstration (RIAD) tool. A site walk-through included visits to BR3 and HADES, an underground research laboratory. 

The third part of the meeting featured two dedicated topical sessions. One was on the use of robotics for decommissioning, including:

  • the current status and challenges of the Fukushima Daiichi decommissioning;
  • the results of an investigation into the Fukushima Daiichi unit 1 containment vessel carried out in 2022-2023 with a submersible remote operated vehicle;
  • the Tokyo Institute of Technology's super long articulated robotic arm named “Super Dragon” and the air purification system at Fukushima Daiichi;
  • robotics in German decommissioning projects;
  • the characterisation of immobilised drummed waste in Sweden;
  • the use of robotics and drones for radiological measurements at US sites performing in-plant and site environmental characterisation;
  • feedback on the use of robotic arms for the decommissioning activities of EDF’s first-generation reactors; and
  • radiological investigations in previously inaccessible rooms using a robotic solution called ISYBOT.

The other topical session was on end-of-life shutdown preparations for decommissioning, including the transition from operation to decommissioning, from a German perspective; and the experience preparing for decommissioning of the Műhleberg nuclear power plant in Switzerland.

The fourth part of the WGDECOM meeting was on the progress made in implementing the group’s programme of work for 2020-2023. This covered compliance with decisions, agreements, commitments, actions and recommendations from the 12th (Germany, October 2022) and 13th (teleconference, June 2023) WGDECOM meetings. Participants approved the new Terms of Reference for 2024-2027.

The results will be presented by the WGDECOM Vice-Chair to the ISOE Management Board at its 33rd meeting at the IAEA in Vienna, Austria, on 4-7 December 2023.

To learn more about the WGDECOM, click here.

See also