Nuclear safety and radiation protection situation in Ukraine

The Federal Environment Ministry is currently analysing the repercussions of Russia’s attacks against Ukraine, which are in violation of international law, particularly with regard to nuclear safety and radiation protection. The BMUV is continuously monitoring the situation, supported by the Federal Office for Radiation Protection (BfS) and the technical support organisation GRS (Gesellschaft für Anlagen- und Reaktorsicherheit). The Ukrainian government, the International Atomic Energy Agency (IAEA) and international partners are sharing their information with Germany.

If there are any indications of increased radioactive levels, the BfS is following up on them. For up-to-date information please refer to the BMUV press releases and Twitter channel and the BfS website and Twitter channel.

Currently, the Ukraine is operating 15 reactors, all of them pressurised water reactors of the Soviet type VVER, at four different sites: Zaporizhzhia NPP (6 units), Rivne NPP (4 units), Khmelnitsky NPP (2 units) and South Ukraine NPP (3 units). In addition, there are three decommissioned units (type RBMK) and the damaged unit 4 at the Chernobyl site. At Chernobyl there are still 21,000 spent fuel elements from units 1 to 3 and the fuel containing masses in unit 4.

None of the Ukrainian nuclear power plants in operation is located in the immediate vicinity of the Russian border or the areas occupied or claimed by separatists (Donetsk Oblast and Luhansk). The Zaporizhzhia NPP is situated approximately 150 kilometres from the Donetsk Oblast and the Russian-occupied Crimean Peninsula. However, Rivne NPP and Chernobyl NPP are just 60 and 10 km away from the Belarussian border.

The consequences of an immediate, direct military attack on a nuclear facility would be unprecedented and cannot be predicted in advance. This also applies to unintentional damage or possible sabotage.

A targeted attack on Ukrainian nuclear power plants with its unpredictable radiological impact – also for Russia and Belarus – would be a crime of unpredictable dimensions and would not be in anyone’s interest, including Russia.

At present, there is no information available to the BMUV concerning specific measures undertaken by Ukraine against targeted attacks on its NPPs. Such measures are the responsibility of the country in which the respective NPP is located, and any information on them is subject to confidentiality.

The following can generally be said: Violent conflicts can give rise to additional risks for reactor safety. Accidental shelling or an aircraft crash can present an immediate hazard. Supply bottlenecks and disruptions to the power grid may also cause safety risks for nuclear power plants.

This is because even a shutdown NPP continues to produce heat (known as decay heat), which requires continued active cooling, although to a lesser extent than during power operation. If the external power supply fails, diesel generators ensure cooling of the shutdown NPP. Fuel supplies are available at the sites to operate these generators for a few days. For the long term, either the external power supply must be restored or the diesel tanks refilled.

The BMUV is currently sharing information with staff of the Ukrainian State Nuclear Regulatory Inspectorate (SNRNIU) through the Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) and the Federal Office for Radiation Protection (BfS). This communication is currently (as per the end of February) complicated due to the situation in Ukraine. The BMUV is also receiving information from the International Atomic Energy Agency (IAEA).

Since the early 1990s, the BMUV has been working together with the Ukrainian State Nuclear Regulatory Inspectorate (SNRNIU). The main goals of this cooperation have been to strengthen the Ukrainian nuclear regulatory authority, increase the safety of Ukrainian nuclear power plants and recover from the consequences of the Chernobyl disaster. Projects are carried out by the Gesellschaft für Anlagen- und Reaktorsicherheit (GRS). If Ukraine asks for technical support and advice, the BMUV will provide it through GRS. In terms of radiation protection, there is also contact with Ukrainian colleagues at the technical (expert) level, in particular at the Federal Office for Radiation Protection (BfS). If Ukrainian colleagues asked for technical support, the BMUV immediately would look at how to provide support in this difficult situation.

On the one hand, any projections about the extent to which Germany could be affected by an attack on a Ukrainian NPP are highly uncertain as there has never been an attack on a nuclear power plant.

On the other hand, Germany has had tools to assess the radiological situation for many years, for example the Integrated Measuring and Information System for the Surveillance of Environmental Radioactivity (IMIS) operated by the Federal Office for Radiation Protection (BfS). The approximately 1,700 measuring probes for the local dose rate and other monitoring networks continuously supply data on environmental radioactivity.

In a radiologically relevant situation, this system can be switched into intensive operation and detect any increase in radioactivity in the atmosphere virtually in real time. This information can then serve as the basis for further monitoring and measuring activities and – if necessary – protective measures. In addition, information is also being shared with partner countries such as Finland which have similar monitoring networks and make their monitoring data available to Germany. The international information system of the IAEA also supplies data.

If the BMUV has any indication that a radiological emergency with major consequences is developing in Ukraine, the Radiological Situation Centre of the Federation (Radiologisches Lagezentrum des Bundes - RLZ) at the BMUV would assess the situation, inform the public and – if necessary – provide recommendations on what action to take.

Due to Germany’s distance to Ukraine, we do not expect that taking iodine tablets could become necessary. People are discouraged from self-medicating as high-dose iodine tablets involve health risks, without any benefit at present.

Iodine tablets are only effective if they are taken at the right time.

High-dose iodine tablets only protect against radioactive iodine being absorbed into the thyroid gland and not against radiation entering the body from the outside or against the effects of radioactive substances other than iodine that have been absorbed into the body.

Please find detailed information on the medical background in the Recommendation by the German Commission on Radiological Protection (SSK) ”Use of Iodine Tablets for Thyroid Blocking in the Event of a Nuclear Emergency with Release of Radioactive Iodine”.

In case of a radiological emergency with an impact on Germany, the Radiological Situation Centre of the Federation (Radiologisches Lagezentrum des Bundes - RLZ) would start working. One of its responsibilities is to provide information to the population that might be affected. In addition, the population would be informed on what to do in case of an emergency.

Around 1,700 measuring probes of the Integrated Measuring and Information System for the Surveillance of Environmental Radioactivity (IMIS) for the local dose rate and other monitoring networks continuously supply data on environmental radioactivity in Germany. In a radiologically relevant situation, this system can be switched into intensive operation and indicate any increase in radioactivity in the atmosphere almost in real time. This then serves as a basis for further measuring activities and – if necessary – protective measures.>/p>

The availability of staff is key for the safety of a nuclear power plant. At the Zaporizhzhia NPP, for example, there are protected rooms for staff members. However, if staff at a nuclear power is under constant siege over several days, as was the case in Chernobyl, they do not only suffer from mental stress due to the military activities, but also from typical symptoms of fatigue and exhaustion because they do not have sufficient rest breaks. This can lead to human error and thus to hazards during the operation of the nuclear power plant. However, according to the Ukrainian State Nuclear Regulatory Inspectorate, staff rotation has already been resumed at the Zaporizhzhia NPP.

In recent years the safety in Ukrainian nuclear power plants has increased considerably, in part through retrofitting programmes. Following the nuclear accident in Fukushima in Japan, Ukraine voluntarily participated in a stress test for nuclear power plants in the EU. Action plans were developed on the basis of the stress test results, making safety-enhancing measures obligatory. These include, for example, the provision of mobile emergency generators and mobile pumps to ensure the water supply of the spent fuel pond and the steam generators and that the spent fuel pond is continuously cooled in the event of a complete power failure for an extended period.

These measures also include refilling the spray ponds required for aftercooling. A spray pond is a pool into which the used heated cooling water is sprayed to allow it to cool down. Cooler water is taken from another part of the pond and used for aftercooling. Aftercooling refers to the reactor cooling once the reactor has been shut down. To guarantee the safety of the containment vessel or the containment against inadmissible pressure build-up, pressure relief possibilities have been and are being created.

Nuclear power plants are protected against external influences. However, if they cannot be cooled and shut down in a systematic, targeted and regulated manner, dangerous situations can arise. The extent of the potential hazard, however, can only be assessed in each specific case.

Nuclear power plants are generally not designed to withstand all kinds of military attacks. The six units in Zaporizhzhia are among the Ukrainian reactors equipped with a better security system against external influences. In accordance with the design of the nuclear power plant, the containments, which are essential for the protection against radioactive leaks, are intended to withstand the impact of an aircraft weighing 10 tonnes and travelling at 750 km/h. The design parameters of the smaller units in the Ukraine are at a lower level.

The containments are designed to withstand pressure waves from bomb impacts. It is not clear to what extent a direct bomb strike on the containment is similar to that of an aircraft. However, the penetration of the containment does not automatically lead to the release of radioactive substances. This would only be the case if there were also a failure of the fuel element cooling in the reactor or in the fuel element storage pool causing damage to the fuel elements (in particular a partial or complete melting of the fuel elements) with particles that could escape to the outside through the damaged containment. It would take either massive mechanical damage to the emergency cooling and aftercooling systems, located in the interior of the containment, or a complete failure of the power or cooling water supply to trigger this kind of cooling failure.

General questions about radiation protection and nuclear safety are answered in these FAQs.