Nuclear Society of Slovenia
& Head of Planning GEN energija
Tomaž’s early introduction to nuclear (0:06)
0:06-8:45 (Tomaž explains how he first became interested in the nuclear sector as a high school student and how he later transitioned to working in a research reactor.)
Q. How did you join the nuclear field?
A. Tomaž Žagar is currently the President of Slovene Nuclear Society and Head of Planning at GEN. Tomaž’s interest in nuclear first began as a high school student. His high school was closely connected to Jožef Stefan Institute, enabling Tomaž to join a research project as a high school student. Here, he mapped contamination from Chernobyl in Slovenia. The contamination included volatiles of mainly cesium and iodine which spread over Europe in a cloud and reached the ground through rain. This research not only gave Tomaž the opportunity to leave the classroom to conduct field work, but also taught him about natural background, the cesium from atomic bomb testing and how mountains with increased rainfall caused Slovenia and Austria to be impacted more than most other European countries from Chernobyl. He also learned that the fallout from Chernobyl was 10 times smaller than that of the atomic bomb testing, understanding that the media emphasizes or deemphasizes magnitudes.
After high school, Tomaž studied physics in university. When he needed to choose an emphasis, he was attracted by energy because Tomaž’s family were engineers. While he thought about pursuing hydrogen power, he thought the nuclear diploma was easier and would help him reach the industrial sector sooner. Tomaž’s first jobs were working in a research reactor measuring fuel depletion. Tomaž created models for prediction and compared this work to what actually occurred in the research reactor. Research reactors are critical in understanding fuel depletion to optimize fuel cycles for power reactors, which do not have the time to undertake research themselves. Research reactors also investigate other topics, including the possibility of recycling fission products.
Fission products and neutron speeds (8:46)
8:46-12:49 (Tomaž explains the limitations of manipulating neutron speeds in reactors.)
Q. How much difference is there between the fission products that are produced based on the fuel type that is in a metal fuel in a TRIGA research reactor versus a uranium oxide mix in a ceramic fuel pellet typical for nuclear power plants?
A. The physics of uranium is the same in each reactor. The enrichment is what differs, changing the speed of neutrons. The material of the reactor and the amount of water used influences this spectrum. It is important to know how uranium reacts to different speeds of neutrons. Once this is known, you can calculate the fission products. This information can be used to calibrate a power reactor and validate tests. This data is collected into libraries and shared within the industry.
Producing less iodine by manipulating neutron speeds to shift the spectrum is difficult. Fission produces many different isotopes. The neutron distributions can be tweaked to an extent, but they are distributed, meaning one change would affect the entire distribution.
Radiation misconceptions (12:50)
12:50-19:13 (Tomaž discusses the common misconceptions about radiation and how radioactive material is not as dangerous as people think.)
Q. We often see radionuclides as dangerous, but in reality they have only hurt a few people and saved billions of lives, right?
A. Yes. For example, technetium is a fission product isotope used in medicine. Additionally, some isotopes can be used for future fuel or in other industries. Not all fission products are useful, but several are. The total waste from a reactor is only about one to two percent while the rest of the products can be recycled. This means that the nuclear power technology is close to zero waste as 97 to 99 percent of products are recycled.
This low waste percentage has somehow been inflated in magnitude. This may be because spent fuel is dangerous and must be handled with care and shielded. However, this shielding need only be 6 meters of water, which is a perfect substrate for shielding fuel. Concrete or steel can also be used for dry storage of spent fuel.
Another misconception is about how far radiation can travel. Radiation is very similar to radio waves. Radio waves can be heard from a meter or an antenna, but distance from a radio wave source removes someone from wave exposure. The only difference is the emitter. For radio waves, everyone can see the source. But for radiation, the source is from atoms which can not be seen by the naked eye. Some people also misunderstand contamination, which is the spreading of radiation emitters. Physical protection and limited access to the sources decreases the possibility of contamination, containing the radiation. Limiting time of exposure also decreases potential for contamination and the radioactive material itself. Radioactive decay is constant and is used to measure the age of the universe. Communicating radiation to the public is sometimes a challenge.
Becoming President of the Slovene Nuclear Society (19:14)
19:14-24:05 (Tomaž expands on his experience within the nuclear sector and how this led him to the Slovene Nuclear Society.)
Q. How did you get involved in the Slovene Nuclear Society?
A. The first president had approached Tomaž and asked if he had wanted to join the Society to translate some publications. The Society was small and wanted to attract more young people in Slovenia to work in nuclear. Tomaž’s experience made him a good fit for the Society.
Tomaž also spent his compulsory army service in his early 20s in chemical defense, which he was assigned based on his prior experience. After Tomaž’s PhD in decommissioning and activation of concrete, Tomaž joined the European joint research center institute in Germany. Here, he looked into the transmutation of uranium, plutonium and other transuranium elements. He returned to Slovenia and decided to approach the utility GEN for work, which was becoming more independent at the time.
24:06-30:15 (Tomaž explains GEN’s resource portfolio and their activity with other European countries.)
Q. What is the portfolio of GEN’s resources and how does GEN think about supplying electrons to the country?
A. Slovenia has two independent utilities. GEN owns the Slovenian half of the Krško nuclear power plant. Between 99.6 and 99.7 percent of GEN’s produced electricity is carbon free. GEN focuses on using both nuclear and hydropower to maximize electricity output. The nuclear and hydro plants are on the same river, allowing GEN to efficiently use the water between the plants in summer months.
The variations between day and night power demands are becoming smaller as society becomes more dependent on electricity. The European market is also becoming more integrated. GEN has a branch dedicated to trading with Central and Eastern Europe and buying and selling electricity between countries. Renewable trading is increasing, as is energy trade from Eastern to Western Europe. Energy consumption is growing, especially in Western Europe, but production is not.
Volatile markets (30:16)
30:16-35:19 (Tomaž discusses why electricity production has not been able to keep up with consumption. He also explains the need to increase public education.)
Q. Why has production not been able to keep up with consumption?
A. Markets are becoming more volatile, making it more difficult to secure investment. The increased number of renewables has caused this volatility. Solar, wind and small hydro receive government subsidies, causing investors to add these sources to national grids. In rare extreme cases this causes market prices to fall below zero when renewables are plentiful, decreasing investment. This means operating on the grid requires utilities to pay.
Society has become complacent, creating a challenging need to communicate to the public where electricity comes from. Decreasing accessibility to electricity also decreases the ability to grow economically and contribute to society.
Challenges of decarbonizing Slovenia (35:20)
35:20-41:01 (Tomaž discusses the challenges of decreasing CO2 in Slovenia.)
Q. Slovenia has the potential to become a leader in clean electricity and could decrease the per person CO2 consumption to zero, right?
A. On paper, this is easy, requiring just three nuclear power units. While we could produce clean electricity all around the world by building two nuclear plants for every two million people, Tomaž thinks this would not be easy. This is because transportation must first be decarbonized and heating demand must decrease. Additionally, some power needs are not directly related to electricity. Only 26 percent of Slovenia’s total power consumption is electricity, meaning a dependence on liquid fuels exists.
While the second generation nuclear plants are already providing district heating to some small European cities, distributing heat over larger distances presents a problem. Using small reactors for heat distribution seems easy when looking at a map. But securing a licensed nuclear energy location is difficult. Tomaž has experience working with nuclear licensing, and understands the paperwork and workload required to secure just one nuclear site.
Nuclear industry strengths (41:02)
41:02-47:05 (Tomaž explains how the nuclear industry is stricter than coal when it comes to regulation and permitting. He also explains how the nuclear industry succeeds at utilizing existing infrastructure and how this can be used to secure society’s reliance on energy.)
Q. How do coal mines get their permits?
A. The nuclear industry is very strict in Slovenia and follows all the best examples and practices. Tomaž questions if the regulations across industries are really on the same playing field.
One of the great skills of the energy industry is how well existing infrastructure is utilized. This includes electricity and gas grids. The nuclear industry can use waste heat and clean heat to provide heating to cities on these well established pipe systems. This clean energy could also be used to produce the incredibly efficient synthetic hydrocarbon fuels. These are easily transported and can be used to power cars. This use case also puts to work employees of the automotive and liquid fuel industries rather than casting these industries aside. Increasing nuclear adoption will secure the future of civilization which relies on access to clean energy. Society has a reliance of 80 percent on fossil fuels and we must replace this with a clean energy source soon.