At the beginning of 2024, the owners of the nuclear power plants Forsmark and Ringhals made a directional decision to extend the operating time of the five existing reactors, from 60 to 80 years. This would provide a supplement of fossil-free electricity totalling to about 800 TWh, which is around six times Sweden’s current electricity consumption per year, an important contribution in light of the fact that the demand for electricity is expected to increase drastically.

“Nuclear power has played and will continue to play an important role in Swedish electricity generation going forward. It is therefore of the utmost importance to continue investing in our existing reactors while planning for new nuclear power. Following the extensive modernisations previously carried out, the conditions are good for extending the operating time by another 20 years,” says Johan Dasht, Head of Business Area Generation at Vattenfall.

After the directional decision was made, an in-depth investigation was initiated to identify what needs to be done and by when, to make detailed cost calculations and to analyse the risks around, among other things, suppliers and competence. The goal is to present the basis for a final investment decision to Vattenfall’s Board and the other owners in 2026.

Major advantages with extended operating time

The feasibility study carried out shows that it is economically efficient to utilise investments already made and that it contributes to an electricity system with low carbon dioxide emissions. The fact that nuclear power will remain for a longer period also creates opportunities for the energy transition. It is a platform and a baseload that stabilises the grid, which increases the opportunity for energy transition in the society and building more wind and solar power.

“Continuing to generate fossil-free power at existing plants is both economically and environmentally beneficial,” says Dasht. “Additionally, the extended operating time for the existing reactors does not entail complex permit processes, and the assessment is also that the extra nuclear waste can be accommodated within the nuclear waste system for the existing reactors.”

The sooner the better

Long-term planning is crucial for operations at Forsmark and Ringhals. Therefore, the sooner this kind of decision is made, the better as it increases the opportunities to optimise processes and measures going forward.

“For the investments we make today, we have a planning horizon of around 60 years, and work based on a given maintenance strategy. With a horizon of 80 years, we can make strategic decisions to instead replace components at an earlier stage and thus avoid unnecessary costs,” says Dasht.

Investments are planned for the 2030s

According to today’s estimates, most of the work will be carried out during the 2030s and will culminate around the year 2035. Apportioning the measures over several years is a conscious strategy based on needs and ability to carry out the work adequately, sustainably and safely.

The investments are estimated at SEK 40–50 billion for replacing or renovating systems and components such as turbines, condensers, generators, and for modernising steering and control systems. Investments will also need to be made in switchgear and power lines, plant buildings and other infrastructure.

“We replace many of the components on an ongoing basis, at different intervals depending on how they wear. The only difference now is that it will be on a larger scale,” says Dasht.

Ensuring adequate competence

The right skills are essential for a project of this magnitude. Being involved and learning from the start provides significant opportunities to build knowledge. The challenge lies in having access to the right basic skills and attracting the best talent, both to Vattenfall and to the supply chain. If done right, a solid base of experience and know-how will be built, that we and the industry will benefit greatly from.

“It is an extremely positive decision for those of us who work in nuclear power as well as for Vattenfall as a company,” says Dasht.