Can Germany restart its nuclear reactors?

The closure of nuclear reactors in Germany poses a significant challenge to the security of supply in Europe while simultaneously delaying the decarbonisation of electricity in Western Europe. Some politicians in Germany say they are ready to restart these units. According to the American consultancy firm Radiant Energy Group, this would be possible for some of them.

On 15 April 2023, Germany closed its last two nuclear reactors: Emsland, Isar 2 and Neckarwestheim 2. At the end of August 2023, the leader of the Christian Democratic Union (CDU), Friedrich Merz, declared that if the CDU were in power, it would launch the restart of nuclear power plants. In July 2023, a report by the Radiant Energy Group, an American consultancy firm, suggested that eight units could be restarted, including five in less than nine months in the “best case scenario”. In their report, the experts calculate that German electricity is now 50% decarbonised, compared with 74% if the country had not phased out nuclear power.

The restarting of German reactors is a complex subject, as there are many factors involved (technical, political, industrial, etc.), and each plant needs to be analysed. The Radiant Energy Group report states that for the restart of these eight reactors, “no insurmountable obstacle has been identified” but that “pragmatism and determination were required”. However, the political obstacle now seems high enough to maintain the situation. The question of the feasibility of such operations could arise again at the next Bundestag elections in 2025, at which point the situation will have to be reviewed again.

A restart with varying degrees of realism

In its analysis, Radiant Energy Group ranks reactors according to the ease with which they can be restarted. There are three criteria: the status of the operating licence, the position of the Länder and the operator’s position. It is important to note that the “licence” column in the table below includes both operating and decommissioning licences. For example, the licence for dismantling the Gundremmingen reactors has already been issued.

Isar 2, ready to restart –  The 1,400 MW reactor is designated as the easiest to restart. Isar-2, which was shut down a few months ago, has the support of both the operator and the Land. According to the Radiant Energy Group, it has enough fuel for “six months of production at full power” and nine months in power modulation. In addition, Isar 2 has not yet received authorisation for dismantling. Finally, the staff could easily be mobilised for the restart.

Brokdorf, Gronde & Krümmel – All three units are supported by the operator (E.on) but not by the Länder in Schleswig-Holstein, Baden-Württemberg or Lower Saxony. From a technical point of view, the Brokdorf reactor would be the easiest to restart. According to a source close to the company, Grohnde carried out decontamination of the circuits (FSD) during the summer – which would pose difficulties in terms of justifying the plant’s high level of safety – and Krümmel is in good condition but would require new equipment, including the turbo-generator set, and therefore new investment.

Neckarwestheim 2 and Emsland: the operators have turned the page – Restarting these plants, closed in April 2023, would require political and industrial support, which seems unlikely in the short term. Especially since the federal government is the main shareholder in the operator, EnBW, that RWE does not wish to continue in the nuclear field.

Grundremmingen B & C – According to the Radiant Energy Group’s report, the two Grundremmingen reactors, shut down in 2017 and 2021, have not undergone any significant decommissioning operations and can therefore be restarted “if decommissioning is suspended by the operator”, says the Radiant Energy Group. It also stresses the need for strong political action at a time when the operator, RWE, has itself thrown in the towel. The site has a decommissioning licence but also an operating licence, as mentioned above. However, “a restart under these conditions would probably be subject to a court ruling, and it is unlikely that RWE would launch such a battle”, explains a source close to the matter.

The case of Fessenheim

In France, the debate sometimes arises in the political sphere over the restarting of the Fessenheim power plant, whose two units were shut down in 2020. But in their case, restarting them is impossible. The plant has entered the pre-dismantling phase, with the dismantling of some of the equipment in the engine room. This equipment is either used in other reactors in the fleet or sent for scrap. In addition, the operating licence has been revoked. Lastly, while maintenance was carried out right up to the last day, the major work required to pass the 40-year barrier was not undertaken. ■


Gaïc Le Gros (Sfen)

Photo ©Shutterstock – Isar nuclear nuclear power plant, 2022.