Leon Cizelj, JSI: Reactors Could Have Lifespans of Up to 100 Years

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Leon Cizelj, JSI: Reactors Could Have Lifespans of Up to 100 Years

Date: January 19^th 2021

Author: Alenka Lena Klopčič

Category: En.vision

Topic: Electricity , Energy policy , New technologies , Nuclear Energy

The lifespans of research reactors – not unlike power reactors or cars – could be, “technically speaking, almost endless”, says Leon Cizelj, the Head of the Reactor Engineering Division at the Jožef Stefan Institute (JSI), Ljubljana. Does this mean that the life of the Krško nuclear power plant could be extended again after the end of its first lifetime extension, provided that steady investment is made in equipment overhaul and upgrades? In principle, it could be, says the nuclear expert, citing cases from the U.S., where operating licenses have been granted for as many as 80 years to plants with similar characteristics than that in Krško. In its latest video interview (in Slovenian only), Energetika.NET spoke to Cizelj about the future of nuclear energy, starting with research reactors.

On issues in nuclear

A big challenge in a nuclear power plant is replacing all the cables, another issue is the reactor vessel, which is exposed to very high levels of radiation. One of the minor problems with units that are 40 or 50 years old, is that very few original equipment producers still exist. This can lead to a situation in which the technologies used may no longer be attractive to young experts, said Cizelj in reply to the question about the lifespans of a nuclear reactors (and the challenges thereof).

Cizelj mentioned the case of France: in its deliberation on whether or not to keep research reactors alive, the country got to the point where it closed all its research reactors while saying it wants to stay an industrial nuclear superpower. Is there any other way France could be successful in its endeavours without research reactors? According to Cizelj, the country is now constructing a large experimental facility called the Jules Horowitz Reactor. However, the reactor will be used for testing materials in radiation environments rather than new types of reactors. In Cizelj’s view, France has gone from a leader to a follower and will struggle to compete with Russia and China.

The fact is that changes in nuclear energy take a very long time, added Cizelj. To illustrate his point, he mentioned small modular reactors, where the U.S. has laid the groundwork with 20 or more years of research. Similarly, it had taken decades of preparation to construct and launch the Krško plant back in the early 1980s.

On the importance of research reactor for Slovenian (nuclear) energy industry

The above suggests that commercial nuclear plants need research reactors as their base. Would Triga, Slovenia’s research reactor, be enough to build a second nuclear unit in Krško, or would the country need Triga 2? If Slovenia decides to add a new unit in the Krško nuclear plant, its primary focus should be on adequately trained staff, said Cizelj. Here, he referred to another case from abroad: Olkiluoto, Finland, where some 500 experts were needed during construction – as many as there are required to operate a running nuclear reactor. Since a similar ratio can be expected in the case of Krško, this requires thorough preparation, and one way to train staff is in a research reactor, noted Cizelj.

In his view, a research reactor is a good small test of the entire system. According to Cizelj, the idea of Triga 2 is worth thinking about, not least because after the second Krško unit has been built (if a decision is taken to this effect), unit 1 will have to be decommissioned, and the Triga research reactor could be a training ground to practice decommissioning.

With lifespans as long as those mentioned in the introduction – up to 80 or even 100 years – it should come as no surprise if the original producers who supplied the equipment are no longer there to service it. This was the case with Westinghouse, said Cizelj. When asked about the memorandum of understanding concerning strategic civil nuclear cooperation, which Slovenia signed with the U.S. in December (MORE, Slovenian only), he said he welcomed it as something that could lead to collaboration at the level of science.

On nuclear, hydrogen, and other ‘nuclear developments’

“When you have negative electricity prices, any technology applied to use surplus nuclear power is good enough,” said Cizelj, adding that solutions such as using nuclear power to produce hydrogen should be considered in advance, while the project for a new reactor is still being developed.

Hydrogen has been widely discussed recently in the EU in the context of the search for clean technology solutions. If Slovenia decides to build the second unit in Krško, should the project consider electrolysis as an option? (This question has been explored in one of Energetika.NET’s articles last year; available in Slovenian only.)

“Yes, definitely,” confirms Cizelj, adding that generation II nuclear reactors, specifically, are not very good at load following, so it is easiest if they are operated at full capacity at all times. Now that the highly variable renewable power capacity keeps growing, it therefore makes sense to combine nuclear power plants with other technological solutions, including hydrogen production.

As regards the power plants that use nuclear fission, there has been much talk of small modular reactors, with some two hundred start-ups working on this technology globally. Lastly, Cizelj also addressed some other developments in nuclear energy, highlighting the importance of science today in an era faced with the need to move towards sustainability.