Russia's invasion of Ukraine is increasingly fraught with a vital connection between Ukrainian nuclear power plants and the power grid. Nuclear facilities rely on outside electricity to keep critical safety systems running, but those links are weakening as power lines are reported to be damaged.
Fuel in nuclear facilities releases a lot of heat. Without the cooling systems, which normally rely on an external power source, the fuel could melt and lead to a catastrophic release of radioactive materials.
There are several levels of backup systems that must fail for the worst case scenario. But fighting and power losses in Ukraine have experts worried about the country's nuclear facilities in the long run.
The war unleashed by Russia in Ukraine denies any rules and conventions. In addition, it touched upon radiation monitoring, communications and long-term maintenance and cleaning of nuclear power plants throughout Ukraine.
Chernobyl, the site of the worst nuclear power plant accident in history, lost electricity the day before due to failure of lines power lines. Zaporizhzhya, Ukraine's largest operating power plant and the site of a terrible fire last week, also suffered damage to two of the four power lines feeding the plant.
So far, the International Atomic Energy Agency (IAEA) has reported that it
“sees no critical safety impact” due to blackout at Chernobyl. Zaporozhye is still under the control of the Ukrainian authorities, but in the six days that have passed since the seizure of the ZNPP by Russian troops, the situation at the facility has only worsened.
A power outage to any nuclear facility is a concern. Electricity from the grid is one of the indispensable pillars of nuclear safety. It keeps the fuel at a safe temperature, preventing meltdowns, and powers key systems for maintaining and monitoring radioactive materials.
There are three main components at Ukraine's nuclear facilities that must remain energized. We'll talk about them later.
Russian troops captured Chernobyl shortly after < strong>Ukraine was invaded on February 24. Since then,spent fuel cooling pools have been the main vulnerability of these sites.. They store most of the fuel from three closed reactors that continued to operate long after the plant's fourth reactor exploded in 1986.
Even spent fuel can release enough heat tocause catastrophic consequences
strong>, so it is usually stored for years in pools and refrigerated. Such pools rely on external power to pump water in and out of the pool, keeping the water surrounding the fuel cool and clean. It also prevents the water from evaporating and reaching the external fuel it is supposed to protect.
Fortunately, Chernobyl's cooling pool is probably safe now, regardless of power outages. This is confirmed by both IAEA experts and other specialists. And all because the fuel stored in it had enough time to cool significantly.
The thermal load of the spent fuel storage pool and the volume of cooling water it contains is sufficient to maintain efficient heat removal without the need for power supply,– according to the IAEA statement dated March 3 after the partial shutdown of the Chernobyl nuclear power plant.
There are also cooling pools in Zaporozhye. The fire broke out at the station on March 4 after the facility was shelled, which was the first ever attack on an operating nuclear power plant. According to the IAEA, the fire was eventually extinguished and the safety systems of the nuclear reactors were not affected. But CEO Rafael Mariano Grossi noted that the situation was on the brink of disaster! Artillery shelling or an uncontrolled fire could cut off the station's connection to the network.
The remains of the reactor that exploded in Chernobyl is another huge problem. It is cordoned off by a giant steel dome that was completed in 2017. This$1.7 billion structure was built to replace an old “sarcophagus” that was hastily built after a 1986 crash to store the remaining 200 metric tons of radioactive materials.
According to Claire Corkhill, Chair of Nuclear Degradation at the University of Sheffield, the ventilation system inside the dome, which requires electricity, prevents corrosion from eating away at what's left of the reactor and the old sarcophagus.
Ukraine's national power grid operator Ukrenergo has called for a ceasefire around Chernobyl and passes for maintenance crews to repair power lines and restore power from the grid. The site has diesel generators with enough fuel to run for48 hours, but that time is running out.
In addition, due to the lack of power supply, there is, accordingly, no communication with the personnel of the station directly located on the site. Regulatory control over the state of nuclear and radiation safety at the plant site and the territory of the exclusion zone, as well as control of nuclear materials at the enterprise is impossible.
Important! Diesel fuel was recently delivered to the station. This was reported in the State Nuclear Regulatory Authority. The volume of diesel should provide emergency power supply to spent nuclear fuel storage facilities.
From day to day, we are seeing a deterioration in the situation at the Chernobyl nuclear power plant, especially radiation safety and for the personnel who manage the facility in extremely difficult conditions. I reiterate my urge to the forces in effective control of the plant to comply with internal radiation protection procedures, facilitate the safe rotation of personnel and take other important steps to ensure safety, Grossi said in a March 9 statement.
< h2 class="news-subtitle cke-markup">Active Reactors
Grossi also drew attention to the deteriorating conditions in Zaporozhye.
“This is yet another example of how the guarantees for providing external power supply to all nuclear facilities from the network have been violated,” she said.
Because this is an operating power plant – the fuel in both the reactors and the spent materials pools is hotter than in Chernobyl. That is why it is important that the plant's cooling systems are connected to the network.
Keeping nuclear power facilities running in a war zone has always been difficult, but more importantly, Ukraine usually gets about half of its electricity from nuclear power plants.
According to the IAEA, this is the first time that war has broken out in a place where the power system is so overwhelmed. powered by nuclear energy.