Nuclear Ship Research Articles

Анализ безопасности плавучего энергоблока при столкновениях

The article considers a possible navigational accident associated with the ramming of a modernized floating power unit (MFPU) by another ship. The authors suggest an approach to determine the consequences of a collision using the finite element method. The finite element model has been developed for modeling the destruction of ship hull structures, to determine the energy intensity of ship hull structures during ramming, and to calculate the critical velocity of ramming ships. The study results provide the following conclusions: 1) the use of the finite element method in the analysis of collisions of nuclear ships helps removing excessive conservatism characteristic of engineering approaches that underestimate the energy intensity of structural elements during destruction. 2) when determining the volume of destruction of the hull structures of colliding ships and the critical velocity of ramming ships, it is necessary to use the model of the deformable bow of a ramming ship. 3) ramming the floating power unit by an icebreaker does not lead to radiation consequences at icebreaker velocity of less than 18 knots. The ramming of an unfastened floating power unit with a similar one caused by extreme natural impacts during its mooring does not lead to radiation consequences, since the critical velocity of the floating power unit of 10.4 knots cannot be achieved. Thus, it is shown that the modernized floating power unit has a high level of safety in case of navigation accidents associated with collisions.

The United States Navy and Employees with Cancer: The Time for Change Is Now.

The US Navy, including the US Marine Corps and Naval Nuclear Propulsion Program (NNPP), has a robust radiological protection and monitoring program meeting (and typically exceeding, in the name of conservatism) federal law requirements. The program covers the variety of ways in which the Navy produces and uses ionizing radiation and radioactive sources: in medicine, nuclear ship propulsion and repair, industrial and aircraft radiography, and myriad other unique uses in carrying out its vital mission. In executing these programs, thousands of people across the world are employed as active-duty Sailors and Marines, government civilians, and government contractors. These workers include physicians, reactor operators, radiation safety officers, and nuclear repair workers, to name but a few. The health protection standards for these workers are promulgated in the publicly available Navy Medicine P-5055 Radiation Health Protection Manual (NAVMED P-5055), published February 2011 with Change 2 published December 2022, and are applicable to Navy and Marine Corps and NNPP radiation protection programs. The NAVMED P-5055 outlines the individual medical requirements for those qualified and able to receive exposure to ionizing radiation as part of their duties and requires that "Radiation workers receive focused medical examinations to establish whether or not cancer is present which would medically disqualify a person from receiving occupational radiation exposure." Additionally, without scientific or medical basis, the NAVMED P-5055 requires disqualifying those employees who have a history of cancer, cancer therapy, radiation therapy including radiopharmaceuticals received for therapeutic purposes, or bone marrow suppression from drawing dosimetry, entering radiation areas, or handling radioactive material. This policy, which exists regardless of lifetime occupational radiation dose or projected future radiation dose, applies to all cancers except adequately treated basal cell carcinoma. The policy is not supported by relevant scientific and medical literature; does not align with reasonable professional ethical standards; does not conform to US Navy radiological training, which stipulates the assumed increased risk of developing cancer from Navy and Marine Corps and NNPP occupational radiation exposure is small; and removes critical leadership and mentoring capability from the workforce unnecessarily. This article discusses in detail (1) this policy and its ramifications to the Navy and Marine Corps and NNPP workforce and (2) recommendations, benefits, and impacts for the Navy and Marine Corps and NNPP to remove this policy and still maintain a robust radiation protection program.

Reliability analysis for the power system of the nuclear ship Savannah

The power system, including the power transmission, distribution, and support system, is one of the largest and most complex systems established by humans. In addition to the normal considerations of power plants on board, the design of nuclear power merchant ships is also based on the need for uninterruptible power supplies. Based on the relevant data of the nuclear power ship “Savannah,” the qualitative and quantitative analysis is performed using the fault tree analysis method to analyze the reliability of its power system. The probability of basic events in certain accident conditions is evaluated according to the literature survey. In addition, this study also examines the common cause failure of diesel generators in the power system, as well as the analysis of sensitivity and importance of basic events. The installation of primary, auxiliary, and emergency power stations, the use of automated equipment for generator synchronization and power conversion, and the application of special internal communication and alarm systems unique to nuclear-powered ships can effectively eliminate the possibility of complete power outages for Savannah.

СОВЕРШЕНСТВОВАНИЕ НОРМАТИВНОГО ОБЕСПЕЧЕНИЯ РАДИАЦИОННОЙ БЕЗОПАСНОСТИ ПЕРСОНАЛА ПРИ УТИЛИЗАЦИИ КОРАБЛЕЙ С ЯДЕРНЫМИ ЭНЕРГЕТИЧЕСКИМИ УСТАНОВКАМИ И СУДОВ АТОМНОГО ТЕХНОЛОГИЧЕСКОГО ОБСЛУЖИВАНИЯ

Results: Information is provided on the developed regulatory and methodological documents including health physics and organizational requirements for the radiation safety and protection supervision in the course of work on decommissioning and dismantling of nuclear submarines, nuclear service ships and surface vessels with nuclear installations, as well as during storage of reactor compartments of decommissioned nuclear submarines and block packs of nuclear service ships. 
 Conclusion: The developed documents are aimed at further improving the regulatory legal and methodological support of citizens’ rights to safe working conditions, health protection and social protection.

Entering new markets: nuclear industry challenges

Nuclear ship propulsion and isolated islands energy supply are unexplored markets for nuclear vendors. Carbon taxes and fuel regulations may make fossil fuels more expensive. Such markets pay more for energy because of organization and transport costs and use of small machines, which are less efficient than grid generators. The goal of this work is to find the measures the nuclear industry needs to take to get into new potential markets. This work shows the different actors and their interests and points the natural or physical constraints they face. Considering interests and constraints, this work named the most probable market niches where nuclear power may beat other power sources. After considering natural constraints, this paper analyses human-generated constraints and presents a way on how to mitigate or solve them. This study shows that nuclear industry needs to take technical, administrative, and political measures before nuclear power arrives to a wider market. This work is based on literature review and qualitative analysis and cannot point precise thresholds where nuclear power should be competitive. Future work will consist of statistical analysis to find precise thresholds to help in the decision-making process.

大型核动力船舶应急计划区分区策略研究

大型核动力船舶应急计划区分区策略研究

Nuclear Ship Reactor Installations: From Gen 1 to 5

The use of nuclear energy on submarines has made autonomous and independent navigation possible for long periods of time. OKBM Afrikantov – one of the leading enterprises of the Rosatom State Corporation – has been supplying Russia’s naval ships with nuclear reactor installations for more than 65 years commencing with the development of equipment for the installations on first-generation submarines. Currently, all active ships – second, third, and fourth generation submarines and nuclear surface ships – are powered by reactor installations developed by OKBM. Commencing with the complete nuclear reactor installation set for the Yasen class nuclear submarine, OKBM has functioned as the complete supplier of equipment for all installations developed and being developed for ships and vessels which are under construction or being modernized. Currently, OKBM is designing ship nuclear reactor installations for promising naval ships.

Аспекты утилизации надводных кораблей с ядерной энергетической установкой в Приморском крае

<b>Object and purpose of research. </b>This study is devoted to the scrapping of nuclear ships for the risk assessment of their decommissioning activities <br><b> Subject matter and methods.</b>Based on available publications, this paper discusses various concepts for scrapping SSV-33 Ural, a large nuclear-powered ELINT ship, in the Primorsky Kray. The study was performed as per common research methods (analysis, comparison, instantiation). <br><b>Main results. </b>This paper investigated the first experience of scrapping a nuclear-powered surface ship in the Primorsky Kray and, taking this Project 1941 ship as a case study, gave an insight to technical and organizational aspects of its scrapping process. <br><b> Conclusion. </b>The study concludes that the floating unit with the reactor compartment of SSV-33 Ural needs further work to reduce its size and weight so that it could be sent to Ustrichny boneyard for long-term storage of reactor compartments. The paper also suggests an alternative variant of decommissioning nuclear-powered surface ships, by unloading their iron-water protection tanks with nuclear steam-generating plant and merge them into a single item for long-term storage, without any intermediate modules.

Study on Rating Method of Nuclear Events in Marine Nuclear Power Plant

According to the operational safety characteristics of marine nuclear power plant and the nuclear safety rating needs of nuclear ships in case of abnormal events during sea navigation, the rating evaluation standards are established referring to the international nuclear event rating table, which consider three aspects of “radioactive safety impact”, “defense in depth capability impact” and “power output impact” in abnormal events. The potential common cause characteristics of the event are additionally considered. Then the rating procedure for nuclear safety events of marine nuclear power plant is proposed. The study is of great significance for accurately evaluating the severity of abnormal events and effectively guaranteeing nuclear safety of marine nuclear power plant.

The Rijeka draft of a Convention on the liability of operators of nuclear ships

Sixty years ago, from 20th to 26th September 1959, the Nineteenth Conference of the International Maritime Committee (Comité Maritime International) was held in Rijeka. Facing the challenges arising from contemporary plans to use nuclear power in marine transport (in particular to use nuclear reactors as a source of transport for both civil and military ships), the Conference adopted a draft of a convention that aimed to address the issue of liability of the operators of nuclear ships. The draft convention reflected the fact that liability issues arising from nuclear ships considerably differ from those issues, arising from the operation of land-based nuclear reactors. This draft convention, which became later widely known as “the Rijeka Draft” in legal literature, provided for basic liability principles that were to be applied to operators of nuclear ships. The Rijeka Draft became crucial for the later developments in the field of international nuclear law, in particular for the adoption of the Brussels Convention on the Liability of Nuclear Ships at the Eleventh Session of the Diplomatic Conference on Maritime Law in 1962. However, it also influenced the content of several other bi-lateral agreements. The 60th anniversary of the Rijeka Draft allows a good opportunity to revisit the principles provided by the draft convention as well as to revisit the impact of this draft on further development of international nuclear law.

Fuel options for nuclear ship reactors featuring reactivity swing below one dollar

Environmental protection against air pollution and climate change has drawn great and increasing public attention in recent decades. Nuclear power involving no pollutant and CO2 emissions provides a more sustainable way for commercial shipping activities. Nine fuel options are simulated to find the combinations of key parameters that make the core to have a lifetime reactivity swing below one dollar. Such a low reactivity swing, when combined with a negative feedback reactivity coefficient, may facilitate passive load follow and passive safety, which means the reactivity can be controlled through temperature or thermal expansion of the reactor core. These fuel options are compared regarding reactor physics and thermal hydraulics, under certain constraints associated with ship reactors. WIMS code is used for burnup, perturbation and parameter calculating. MONK and SERPENT codes are used to verify the WIMS model. It is found that ship-based lead-cooled fast reactor can be designed to have superior core safety and good economics. Different fuel options show diverse characteristics in terms of power output limits, refuelling intervals, natural circulation cooling capabilities and other safety related parameters.

Оценка радиационной обстановки в районе расположения судоремонтных предприятий, осуществляющих утилизацию судов с ядерной энергетической установкой

Purpose: To study radiation and health physics situation in the vicinity of the shipyards “The 10th Shipyard, a Holder of Order of the Red Banner of Labor” (JSC “10 SRZ”) and “The Nerpa Shipyard” – a branch of the JSC “The Shipyard Center “Zvezdochka” (SRZ “Nerpa”) after the completion of the main stage of nuclear submarine dismantling and to assess potential effect of on-going activities to the environment and population.
 Material and methods: The following methods were used in radiation survey: pedestrian gamma survey of the site using portable gamma spectrometry complexes, gamma spectrometry and radiochemistry methods to determine the activity of manmade radionuclides in samples of environmental media. 
 Results: Radiation and health physics studies were carried out from 2013 till 2017. It was shown that gamma dose rate within the health protection zones and supervision areas (SA) of the shipyards including the territories of the nearest cities – Snezhnogorsk and Polyarnyi – was at the level of regional values and did not exceed 0.14 µSv/h. The activities of radionuclides in soil from the surveyed sites did not exceed 23 Bq/kg for 90Sr and 100 Bq/kg for 137Cs. Concentrations of 90Sr and 137Cs in plants (mosses) at the surveyed sites did not exceed 70 and 48 Bq/kg, respectively, this is a bit higher than the background levels of the reference village of Belokamenka (1 and 20 Bq/kg, respectively, for 90Sr and 137Cs). The activity of seawater (Barents Sea) in 2016–2018 reached 60 mBq/l for 90Sr and 4 mBq/l for 137Cs, at mean values from 2 to 4 mBq/l over the period between 1990 and 2000 for the studied radionuclides. Data for 137Cs and 90Sr measured in samples of local wild plants, in particular, mushrooms, did not exceed 100 Bq/kg, this is much lower than the established permissible specific activities.
 Conclusion: Considerable impact of the work on the dismantling of nuclear submarines, maintenance ships and ships with a nuclear energy installation on the radiation situation in the areas of shipyards and health effects in the population of Snezhnogorsk and Polyarnyi was not revealed. However, along the external border of the surveyed shipyards some local parts of the sites of 5500 m2 area were found, where the specific activities of 90Sr and 137Cs in soil exceeded background levels and bordered by the level of permissible specific activity for unlimited use of solid materials (137Cs – 100 Bq/kg).

Nuclear Power Plants for the Icebreaker Fleet and Power Generation in the Arctic Region: Development Experience and Future Prospects

The technical characteristics of a power series of reactor installations developed at Afrikantov OKBM are presented. The technical qualities making facilities equipped with modern ship reactor installations commercially attractive are shown to have undergone evolutionary improvement. First and foremost these are facilities for universal nuclear icebreakers under construction and an icebreaker in the design stage. Designs of optimized floating and ground-based power-generating units with improved user qualities are being developed on the basis of the experience gained in the development of a floating nuclear heat-and-power plant based on the Akademik Lomonosov floating power-generating unit. Promising reactors of the type RITM are used in these designs. They differ fundamentally from the block-type units by the integral steam-generating unit, heightened energy resource, and long intervals between refuelings, which are possible owing to the innovative core with metal-ceramic fuel and new structural materials. The possibility of significantly increasing the resource of the new reactor installations is confirmed by its stepped increase on operating nuclear ships and by scientific-technical studies.

Обоснование ядерной и радиационной безопасности атомного судна при внешних воздействиях

Обоснование ядерной и радиационной безопасности атомного судна при внешних воздействиях

Bolt fatigue parametric study of a bolted assembly

Structural integrity of aircraft, nuclear power plants, space rockets, ships, automotive structures, biomedical devices, and many other applications, is a major design purpose and concerns various components subjected to cyclic loads for which fatigue is generally the dominant factor leading to its failure. The fatigue damage cumulation phenomenon is a process which may lead to cracks initiation and possibly to the structure failure under the action of variables stresses cycles. The mechanical components are generally subjected to multiaxial stress states. Taking into account this stress states triaxiality generally deals with multiaxial fatigue criteria. They are suitable tools for assessing the material fatigue resistance against periodical stress states, especially when they are multiaxial. The study carried out in this paper aims to analyze the fatigue behaviour of pre-stressed bolts involved in a so-called tee-stub bolted assembly that is subjected to variable loads. A multiaxial fatigue post-processing tool using two multiaxial fatigue approaches (integral approach and critical plan approach) is developed and implemented on Matlab software in order to assess the bolt fatigue damage and then its fatigue life through an iterative process. The tool is validated by fatigue test results on bolted assemblies found in the literature, which are additionally compared with those obtained by standards (Eurocode, VDI). A parametric study on the tee-stub is then performed.

Archaeological Survey of the Ex-USS Bugara (SS/AGSS331)

In August 2017, a multidisciplinary team conducted the first archaeological survey of the deep water (242 m) wreck of the ex-USS Bugara (SS/AGSS331) using the remotely operated vehicles Argus and Hercules. The survey provided 8 h of direct observation with video and still camera documentation of the wreck, which previously had been identified by sonar and a brief ROV survey of portions of the hull in 2001. The 2017 assessment added considerably to an understanding of changes to Bugara after it sank while under tow in 1971. Bugara, a World War II-era submarine, served at the end of that conflict and through the Cold War. The submarine reflects a series of modifications to “modernize” it within the context of the Cold War. The examination of the wreck, along with additional archival research, offers more details not only on the probable cause of the sinking but also on subsequent site formation processes. The characterization of the wreck resulted in a reassessment of the site as more than an obsolete vessel accidentally lost when relegated to target practice. The archival record, now declassified, shows that Bugara’s loss also reflects its ultimate use, within the context of the Cold War, as a target for the Mark 48 torpedo, a newly developed “sub and ship killing” weapon designed in the late 1960s and tested through 1971 to take out Soviet deep-diving nuclear submarines and high-performance surface ships.

Comparative Analysis of Thermodynamic Cycles of Selected Nuclear Ship Power Plants With High-Temperature Helium-Cooled Nuclear Reactor

Abstract This paper presents a comparative analysis of thermodynamic cycles of two ship power plant systems with a high-temperature helium-cooled nuclear reactor. The first of them is a gas system with recuperator, in which classical gas chamber is substituted for a HTGR reactor (High Temperature Gas-cooled Reactor). The second of the considered cycles is a combined gas-steam system where working medium flux from gas turbine outlet is directed into waste heat boiler and its heat is utilized for production of superheated steam to drive steam turbine. Preliminary calculations of the combine cycles showed that it is necessary to expand the system by adding to its steam part an inter-stage overheat for secondary steam, owing to that a required degree of steam dryness at outlet from the turbine can be reached, ensuring its correct operational conditions. The analyzed power systems were compared to each other with regard to efficiency of their thermodynamic cycles. Also, efficiency of particular cycles were subjected to optimization in respect to such parameters as : working gas temperature at outlet from reactor in gas system as well as steam pressure at outlet from waste heat boiler and partition pressure in steam part of combined system. Advantages of nuclear power plants compared with the classical power systems dominating currently in sea transport were also discussed.

Performance Analysis of a Naval Reactor for Nuclear Powered Ship

Abstract Nuclear power-driven ships are becoming progressively more popular in advancing ship technology. Nuclear ships use naval reactors, which have lower fuel costs and last for many years and have almost zero emissions. The working of a Nuclear Ship is derived from the simple nuclear fission reaction. One more important factor that has spurred on the continuous investigates of nuclear power generation within ships is the irregular cost of flammable fuels. The unfavorable effects of burnt fuel being dispelled into the sea are also a concerning factor for green and sea life activists. Nuclear power applications have been limited due to safety concerns, but the new war against global warming is perched to drive its progress. In a span of a few years, safety risks may be minimized and nuclear power for power generation, in medicine and aboard ships and even in cars—may be the norm. The paper focuses the analysis of design for a nuclear-powered ship and the subsequent safety analysis of that ship in comparison with its fossil fuel ship. The final result of this paper shows that a suitable naval reactor for developing nuclear powered ship, while being technically feasible, will alternative to a fossil fuel powered ship. Keywords : Fuel cost, naval reactor, nuclear propulsion and ship designs Cite this Article Juwel M.M.H., Khondoker M.R.H., Khan R.A.. Performance Analysis of a Naval Reactor for Nuclear Powered Ship. Journal of Nuclear Engineering & Technology . 2018; 8(1): 1–6p.

China’s Naval Leadership Reshuffle, Evolving Maritime Strategy and Professionalisation

Appointing a naval officer to command the Southern Theatre indicates the relative importance of the South China Sea to the People’s Liberation Army (PLA), mainly in terms of its strategic location and its deep depth, immense space and unfettered transit to the Western Pacific for operating PLA Navy’s strategic nuclear submarines and major surface ships. For the reshuffling of naval leadership, functional and technical expertise-based, or professional criteria may play a primary role.

Аспекты утилизации судов атомного технологического обслуживания в Приморском крае

Аспекты утилизации судов атомного технологического обслуживания в Приморском крае