The modern energy market is undergoing permanent development despite all international conflicts, political crises and the global agenda to reduce dependence on minerals and carbon footprint. On the other hand, it is the last point that significantly affects the implementation of many projects, both in the field of fossil sources and in the field of renewable energy (hereinafter referred to as RES), as well as other alternative solutions.

Various subjects of international relations choose the most suitable ones for themselves, in terms of geographical location and scientific potential, energy sources. By far the most common are: oil, gas, hydropower and nuclear power.

Despite the fact that the development of nuclear energy began almost immediately after the end of World War II, which was based on the research obtained during the development of weapons of mass destruction, modern technologies, on the one hand, have largely moved away from the first reactor installations (hereinafter referred to as RI), but on the other hand, they have retained the fundamental principles principles.

Today, various types of RI are actively developing. Large reactors such as VVER-1200 or HPR1000 do not always meet the needs of new customers, the main reasons are the high cost of implementing projects and the lack of need for a large amount of electricity. Based on this reason, the world's leading companies are actively engaged in the design of small, medium and modular reactors (hereinafter - SMMR), whose capacity is limited to 300 MW. The main designs that exist today are: RITM-200 (Russian Federation), KAREM (Argentina), SMART (Republic of Korea). The applicability of SMMR is quite wide, since they can be used not only as a source of electricity for densely populated areas, but also as an energy source for individual industries, remote settlements without central electricity supply, as well as as an energy installation on ships.

Despite the wide range of potential uses, the international community today faces a significant problem in the field of regulatory regulation of the SMMR, since reactors of this type have their own peculiarity, which limits the applicability of existing documentation. This problem is especially evident when it comes to small high—temperature gas—cooled reactors (hereinafter referred to as HTGR) and molten salt reactors (hereinafter referred to as MSR), where, in addition to their compact size, there is a problem of determining materials applicable to the construction of the reactor and the plant as a whole, since the operating temperature of HTGR exceeds 600 degrees Celsius and can reach 1000, the construction of metal structures should be made of heat-resistant materials, the temperature limits of which allow them to function within the specified limits. Another problem with MSR is its design features, which complicate the application of the principle of deep-layered protection.

However, in this work, special attention is paid to the use of small modular (Hereinafter — SMR) light-water reactors, the active use of which is implied on ships, including ice navigation.

During the history of shipbuilding in the world, it has been designed and used

4 nuclear-powered commercial vessels: Savvana (USA), Otto Hahn (Germany), Mutsu (Japan) and Sevmorput (USSR). Three of them, shortly after entering into the operation, were returned to ports and no longer used as nuclear-powered ships. The main reasons, in addition to the complex design, were economic inexpediency and the lack of international practice in the field of regulation, which complicated the passage of the vessel through the territorial waters of third countries and its stay in the ports of destination. Moreover, the general mood among the population of many states, after the accidents at the Three Mail Island station and the Chernobyl nuclear power plant, had a negative impact on the development of the nuclear industry and was characterized by disregard for the use of nuclear fuel in general.

Since then, the only country that has continued to develop nuclear shipping is Russia. The Sevmorput, which was previously mentioned, remained the only nuclear-powered vessel operating to this day. At different times, this vessel was sailing to Odessa, Vietnam, Vladivostok, North Korea, Murmansk and Dudinka. In addition to lighter, the Russian Federation has 7 operating icebreakers and 4 under construction. So, on January the 26th of 2024, the President of the Russian Federation launched the construction of the fifth serial universal nuclear icebreaker project 22220 Leningrad.

The Russian Navy also houses the world's only floating nuclear power plant (hereinafter referred to as the FNPP) named after. Academician Lomonosov.

Based on the above, it can be argued that Russia is the most developed country in the field of using nuclear energy at sea.

At the same time, against the background of the successful functioning of the domestic nuclear fleet and the emergence of new SMR designs, many foreign companies are increasingly showing interest in the development of this area.

Despite the attractiveness of this sector and the economic prospects it brings, experts around the world are increasingly talking about the need to create an appropriate regulatory framework capable of fully regulating the activities of nuclear-powered ships in international and territorial waters. Such a position is the most pragmatic, since analysing the existing experience, it can be concluded that all the technologies being developed can remain only on paper and have no implementation, in the absence of further changes in the field of regulation.

For this reason, many nuclear regulators, along with maritime registries, were concerned about the lack of suitable documentation, since most of them are either outdated or do not cover the full range of modern technologies, such as FNPP.

Today, there is a system of regulation of the law of the sea, which includes such fundamental documents as the UN Convention on the Law of the Sea and the Convention for the Safety of Human Life at Sea.

However, in the context of legal regulation, I would like to pay special attention to the applicability of international documents to FNPP, as the most complex element of this area.

Despite the fact that many experts provided a list of regulatory documents related to the regulation of the FNPP, their list was relatively incomplete and missed some fundamental documents necessary for the development of this area. Speaking of IMO documents that could potentially be applicable to the transportation

and operation of a floating nuclear power plant, it is worth mentioning:

1. The 1982 United Nations Convention on the Law of the Sea

2. International Convention for the Safety of Life at Sea – SOLAS 1974

3. International Code for the Carriage of Dangerous Goods by Sea 1965

4. The Code of Safety of Special Purpose Vessels of 1984

5. International Convention for the Prevention of Pollution from Ships — MARPOL 1973

6. International Code for the Safe Transport of Spent Nuclear Fuel, Plutonium and Highly Radioactive Waste in Containers on Ships 1999

7. Maritime Labour Convention, 2006

8. Guidelines for First Aid in Case of Accidents involving Dangerous Goods 1998

9. Emergency response procedures for ships carrying dangerous goods, including emergency schedules 1997

10. International Convention on the Training and Certification of Seafarers and Watchkeeping, 1978

It should be emphasized that due to the presence of RI at the FNPP, its regulation is not limited only to the IMO sphere, it includes the IAEA recommendations in the field of nuclear safety and security, as well as radioactive fuel management. However, I would like to mention two of the most relevant and important documents for the legal basis of the activity of the FNPP.

The first document is "Safety Consideration in the Use of ports and Approaches by Nuclear Merchant Ships", which was created jointly by IMO and the IAEA and outlined considerations related to the safe use of ports and harbors by ships with nuclear installations. However, to date, this document is invalid and will require further revision in order to update the available information and re-enter it into force. The second and no less important, created in 1981 and a pleasant resolution A. 491 (XII) is the Code for the Safety of Nuclear Merchant Ships (hereinafter referred to as the Code of Nuclear Ships). This document was developed as a guide for administrations on internationally recognised safety standards in the design, construction, operation, maintenance, inspection, salvage and disposal of nuclear merchant ships. It is an addition to international conventions, in particular to article VIII of the SOLAS Convention, as well as to the codes and recommendations adopted by IMO.

It is worth noting that this document does not lose its relevance to this day, despite its adoption more than 40 years ago. The Code of Nuclear Vessels is an integral part of many documents regulating the use of atomic energy on the water surface. As an example, we can consider the "federal rules and regulations" of the Russian Federation in the field of nuclear energy use. Thus, in the preamble NP-022-17 "General safety assurance provisions for ships and other floating craft with nuclear reactor", the names of the fundamental documents are indicated: "Developed on the basis of regulatory legal documents of the Russian Federation, federal norms and regulations in the field of the use of atomic energy, the rules of the classification Society "Russian Maritime Register of Shipping", as well as taking into account the IAEA documents "Fundamental Safety Principles. Safety Fundamentals" (SF-1), IMO "Code for the Safety of Nuclear Merchant Ships" (Resolution A.491(XII) of 11/19/1981.) [3].

An example of the use of the Code of Nuclear Ships by foreign States is a document of the United Kingdom of Great Britain and Northern Ireland "Guide. Nuclear vessels MGN 679 (N)" in the introduction of which there are references to two significant IMO documents in the field of regulation of nuclear-powered vessels, which in turn served as the basis for the creation of their own internal document of the United Kingdom. "1.1 This notification contains guidance on the application of the Merchant Shipping (Nuclear-powered Vessels) Regulations 2022 (SI 2022/1169) ("Rules 2022"), which implement Chapter VIII of the Annex to the International Convention for the Safety of Human Life at Sea 1974 (SOLAS), concerning commercial vessels with nuclear engines ships. The 2022 Rules also include the provisions of IMO resolution A.491 "Code of Safety for Nuclear Merchant Ships" ("The Nuclear Code"), which contains the basic requirements for the design, construction and operation of nuclear vessels and is intended to become a global standard."

According to this document, its main objectives are: 1) protection of people and the environment from the dangers associated with the exit and the further spread of radioactive substances; 2) ensuring the safety of the vessel not only from the point of view of the RI, but also from the interaction of the nuclear installation with the environment, personnel and the structure of the vessel. The Nuclear Ship Code is a comprehensive guide for Administrations in the field of regulating the use of nuclear energy at sea, which provides recommendations regarding design criteria both for the RI and for the ship, including in terms of the use of mechanical and electrical installations, reactor core and protection systems, instrumentation, rescue equipment and fuel behavior in the reactor. The document also pays attention to the training and sufficient qualifications of the personnel of the vessel, and the skills that they must possess.
Thus, the relevance of this document is confirmed by the fact that the leading states of the world use and implement it into domestic legislation to this day. However, despite this fact, the Code of Nuclear Ships requires revision not only within the framework of the International Maritime Organization, but also with the involvement of expert opinion from the IAEA, for example, within the framework of the International Nuclear Safety Advisory Group (INSAG). This need is due to the creation of modern safety systems, both active and passive, the comprehensive development of the nuclear industry, a vivid example of which are new types of reactors MSR and HTGR, as well as the creation of and the functioning of a floating nuclear power plant, about which, in 1981, few people thought. In addition, the regulatory framework regarding the international recommendations of the IAEA has also undergone significant changes, which may be applicable in the future to the Code of Nuclear Ships. Moreover, it should be noted that the existing experience of the Russian Federation in terms of the creation and regulation of nuclear vessels can be laid down as the basis for future work in this area.

In conclusion, it should be emphasized that the new challenges that arise as a result of the development and creation of new technologies in the nuclear energy sector, require consolidated efforts from not only international organizations such as the IAEA and IMO, but also from States.

In this case, international entities can be divided into vendor countries that have technologies for the creation and operation of reactor installations on water and those that, due to their geographical location or economic industry, plan to locate in the territorial waters the FNPP in the near future. Consideration of the points of view of both sides, with the participation of international organizations, will allow us to obtain the most understandable and complete picture of the situation in which the world community currently finds itself, including the most acute and weak aspects of international legal regulation of the use of nuclear energy at sea.

Moreover, the set of international legal documents that currently exists within the framework of the International Maritime Organization and which can be used with respect to ships with RI requires detailed consideration and analysis to identify weaknesses, which means the absence of requirements for floating nuclear power plants or the impossibility of their application from the point of view of the technical features of the FNPP.

In conclusion, it should be noted that the regulation of the activity of the FNPP can be divided into two stages. The first is the transportation of the station to its destination, which, is most likely to be carried out using a semi—submersible cargo ship, an example of which is MV Blue Marlin. The second is the operation of the NPP in the territorial waters of the receiving State, where international legal regulation is also necessary to prevent the occurrence of situations involving both pollution of the international ocean and danger to the population of the country importing electricity.