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Men stationed on nuclear-powered submarines are occupationally exposed to external ionizing radiation at very low levels and radiation dose for each individual is closely monitored. Little is known about ionizing radiation (IR) risks of cancer mortality for populations with levels of cumulative ionizing radiation exposure this low. This historical cohort study followed 85,033 enlisted men who had served on a nuclear-powered submarine in the U.S. Navy between 1969 and 1982 to determine patterns of cancer mortality. Occupational radiation doses were measured by badge dosimeters for each individual for all periods of Navy service potentially involving radiation exposure. Deaths were ascertained through 1995 by searches of multiple national mortality databases. Within-cohort dose-response relationships for cancer mortality were estimated using linear Poisson regression models. Individual-level smoking status was not available so cancer risks were estimated separately for cancers with and without previously published evidence of consistently moderate or strong associations with smoking. A total of 584 cancer deaths occurred during a follow-up period of up to 27 years. The mean and median cumulative occupational radiation doses received while in the Navy were 5.7 and 1.1 milliSieverts (mSv), respectively, range 0-242 mSv. Mortality Excess Relative Risks (ERRs) per 10 mSv and 95% confidence intervals (CI) were 0.053 (CI -0.03, 0.17) for all cancers, 0.052 (CI -0.03, 0.18) for all solid cancers, and 0.003 (CI -0.29, 0.30) for leukemias excluding chronic lymphocytic leukemia. The ERRs per 10 mSv were 0.052 (CI -0.07, 0.17) for cancers previously associated with smoking and 0.012 (CI -0.10, 0.12) for cancers that were not. The ERR point estimates for solid cancers and leukemia were statistically compatible with those reported in previously published studies of other ionizing radiation-exposed and monitored cohorts, albeit with wide confidence intervals. This study, with high-quality measurements of in-Navy occupational external IR doses, high follow-up proportion, and detailed IR dose-response analyses, is consistent with the premise of small excess cancer risks from low-dose IR.
To describe the long-term mortality experience of a cohort of enlisted men who served on nuclear-powered submarines in the United States Navy and breathed recirculated filtered air for extended periods of time. In this historical cohort study we estimated standardized mortality ratios (SMRs) and used within-cohort Poisson regression analyses to address healthy worker biases. Three thousand two hundred sixty three deaths occurred among 85,498 men during 1,926,875 person-years of follow-up from 1969 to 1995. SMRs were reduced for most cause-of-death categories, prostate cancer had a twofold elevation. In within-cohort comparisons, prostate cancer mortality did not increase with duration of submarine service, but ischemic heart disease mortality increased 26% per 5 years of submarine service. Long periods of submarine service do not increase mortality in most cause-of-death categories. Increased mortality from ischemic heart disease likely reflects the effects of tobacco smoke.
The impact of a pharmacy officer on patient compliance and blood pressure control on a deployed nuclear-powered aircraft carrier for a 2-week at-sea period was evaluated. Before any counseling by a pharmacy officer, 43 crewmembers on chronic medications anonymously completed a compliance questionnaire. The pharmacy officer then counseled these crewmembers. A follow-up compliance questionnaire was completed 2 weeks later. After counseling, compliance had increased 58% (p < 0.0001) from compliance measured before counseling. The pharmacy officer also initiated therapeutic interventions. Among 26 crewmembers diagnosed as hypertensive, preintervention blood pressure (BP) measurements were obtained. Ten to 14 days after the initial BP measurement, BP was remeasured. After intervention, 31% (p < 0.02) more crewmembers were at BP goal compared with before intervention. A pharmacy officer, working closely with a medical officer, improved patient compliance and blood pressure control. One problem identified was that these warships require computer software that can prospectively identify drug-drug interactions.
The influence of nuclear-powered utilization (disjunction) upon the state of health of the soil, vegetation and atmospheric air was studied. It was stated that the concentration of hazardous metals in the air of an industrial site did not exceed the permissible levels. In the residential area the cases of increased concentrations of manganese and chromium were noted. The major pollutants of vegetation are manganese, titanium, copper and nickel. The authors propose a complex of anthropogenic factors to be the cause of the environmental contamination by hard metals. The volume activity of radioactive aerosols in the studied site is confined to the local hum.
From 1973 through 1987, 164 radioisotope powered ("nuclear") pacemakers were implanted in 139 patients at the Newark Beth Israel Medical Center. Patient survival was much as might be expected from an age group as selected for this program. At 31 years (January 2005), 12 of the 139 patients (9%) were still alive. The experience reported here encompassed a span of 16 years of implantation with a follow-up of slightly more than 31 years. The problems encountered along the way were not remarkably different from those encountered in general clinical experience with pacemakers, except that the number of reoperations was fewer. In fact, most patients died with the initial implant in place. Deaths most commonly were due to cardiac causes (54%). The frequency of malignancies was similar to that of the age-matched population; primary tumor sites were randomly distributed. These results show that nuclear pacemakers were safe and reliable. Their longevity and the resulting decrease in reoperations offset their greater initial cost.
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In the current geopolitical context, the possibility of a radiological incident resulting from an attack on nuclear infrastructure or a nuclear-powered naval vessel in active maritime theaters of conflict cannot be entirely dismissed. This paper presents a suite of Lagrangian radionuclide transport models covering the marine domains most directly affected by the present Middle East war: the Red Sea, the Persian Gulf, and the Northern Indian Ocean. The models incorporate advection by currents derived from a global ocean model, three-dimensional turbulent mixing, radioactive decay, and dynamic water-sediment interactions described through reversible kinetic adsorption-release reactions. Tidal transport, which is particularly relevant in semi-enclosed basins such as the Persian Gulf and the Red Sea, can be optionally included via tidal currents obtained from a previously validated tidal propagation model. The modelling framework is consistent with the recommendations of the International Atomic Energy Agency MODARIA programme regarding the availability of marine radionuclide transport tools for rapid deployment in nuclear emergency scenarios. Some illustrative simulations of a hypothetical release of 137Cs from a nuclear facility located in the southern Persian Gulf and from a ship in the entrance of the Gulf of Oman are presented. The models are ready to be operationally applied should a radiological emergency arise in any of these regions.
This paper innovatively presents an integrated nuclear-powered supercritical carbon dioxide (S-CO2) system for aircraft carriers, replacing the conventional secondary-loop steam Rankine cycle with a regenerative S-CO2 power cycle. The system comprises two modules: a nuclear reactor module and a S-CO2 power module. Comprehensive thermodynamic, economic, and compactness analyses were conducted, using exergy efficiency, levelized energy cost (LEC), and heat transfer area per unit power output (APR) as objective functions for optimization. Parameter analysis revealed the influence of key operating parameters on system performance, and a multi-objective optimization approach based on genetic algorithms was employed to determine optimal system parameters. The results indicate that the system achieves an exergy efficiency of 45%, an APR of 0.168 m2 kW-1, and an LEC of 2.1 cents/(kW·h). This high compactness, combined with superior thermodynamic and economic performance, underscores the feasibility of the S-CO2 system for integration into nuclear-powered aircraft carriers, offering significant potential to enhance their overall performance and operational efficiency.
There has been an increase in the activities of naval nuclear-powered vessels in the High North and vessels carrying radioactive waste along the Norwegian coastline. Previously, there have been incidents with such vessels in the sea area near Norway, which also require emergency handling from the Norwegian authorities. This article gives some examples of historical events that have been particularly interesting. The incidents include reactor or cooling system failures, fires and the actions of crews.
Our goal is to improve the aerothermodynamics performance of the marine nuclear-powered turbine and control the exhaust humidity of the blade grid, thereby improving the operating efficiency and power of the turbine and ensuring safety. We propose a method for parameterized reconstruction of steam turbine blade profiles based on their geometric parameters using a coordinate equation developed based on the third-order Bezier curve. By combining the blade parameterized reconstruction method with a Kriging approximation model and a multi-objective genetic algorithm (GA), we developed an optimized system for thermodynamic performance in turbines. The optimization objective was the cascade core thermal parameters of steam turbine under multiple operating conditions. The design parameters were the geometric parameters of the parameterized blade profile. Based on the calculation results of wet steam non-equilibrium condensation flow of steam turbine, the optimization method and process of multi-objective thermodynamic performance of steam turbine blades based on Kriging model were proposed. Then, we executed parameterized reconstruction of a Dykas planar cascade and a steam turbine 3D cascade to achieve multi-parameter, multi-condition design optimization of planar and 3D cascades. The analysis results showed that after optimizing the turbine cascade under different operating conditions, the outlet humidity decreased by 6.1-8.9%, the maximum droplet diameter decreased by 11.4-15.8%, and the isentropic efficiency increased by 0.6-0.9%. Using the proposed novel method, the isentropic efficiency and stage power of steam turbine cascades at variable operating conditions were enhanced, thermodynamic parameters (e.g., velocity, temperature, and pressure) were more homogeneously distributed, and overload condition sites showed more significant improvements. Thus, the proposed method achieved multi-condition, multi-constraint thermodynamic performance design optimization of wet steam turbine blades, thereby providing insights for intelligent design optimization and operation of wet steam turbine cascades.
The Arctic region is facing growing demands for energy to support various economic activities, while also grappling with the profound impacts of climate change. Black carbon particulate matter emissions reduction is a key objective to mitigate the susceptibility of the Arctic's ecosystems to the impact of climate change. Nuclear power has been suggested as a potential source of clean energy to decarbonize maritime transport in the Arctic. However, although the operation of nuclear-powered vessels and floating nuclear power platforms in the region ensures energy security and reduces black carbon emissions, it may pose significant risks of nuclear material release and radiological accidents and raise concerns about improper radioactive waste disposal. In regulating these nuclear-powered vessels and floating nuclear power platforms in the Arctic, the existing international legal regime faced a series of challenges. This research employs a method of policy analysis to analyze these legal challenges and explores how the international community could work together to cope with the challenges that arise in the Arctic during the operation of nuclear-powered vessels and platforms for maritime decarbonization purposes.
Submarines represent extremely confined environments where breathing air is continuously recirculated for extended periods with minimal renewal, generating complex multipollutant atmospheres. This critical narrative review aims to (i) summarize sources and composition of submarine indoor air, (ii) evaluate respiratory and cardiovascular risks for crews, and (iii) assess current purification technologies. A narrative review was conducted following PRISMA recommendations applicable to non-systematic reviews. The PubMed search covered all years from inception to September 2025, complemented by backward citation tracking and technical reports. Eligible studies consistently report elevated levels of CO2, VOCs, NOX, CO, PM2.5, and bioaerosols aboard submarines. Evidence from submariner cohorts and toxicological studies indicates risks of airway irritation, impaired mucociliary defenses, endothelial dysfunction, cardiovascular stress, and neurobehavioral alterations. Submarine indoor air quality is a credible determinant of crew health. Existing filtration systems mitigate some risks but do not address multipollutant mixtures adequately. Improved real-time monitoring, advanced filtration, CFD-guided airflow optimization, and longitudinal medical surveillance are necessary.
In recent years, the use of nuclear energy as propulsion for merchant ships has been proposed as a means of promoting the transition toward maritime decarbonization and environmentally sustainable shipping. However, there are concerns that nuclear-powered merchant ships could pose risks to the marine environment in the event of accidents, such as collisions, machinery failure or damage, fire, or explosions. The current international regulatory framework for nuclear-powered merchant ships is insufficient to address these risks. This research aims to address this gap by conducting a policy analysis of the existing regulations and a critical examination of their effectiveness in addressing the environmental risks of nuclear-powered merchant ships. Through this analysis, the study identifies the shortcomings and insufficiencies in the current framework and explores potential solutions to improve it, with the goal of enhancing the international community's ability to mitigate the potential impacts of radioactive marine pollution from nuclear-propelled ships in an era of maritime decarbonization.
The effects of thermal radiation and thermophoretic particles deposition (TPD) on the hybrid nanofluid (HNF) flow across a circling sphere have momentous roles in research and engineering. Such as electrical devices, projectiles, thermal conveyance, sheet production, renewable energy, and nuclear-powered plants. Therefore, the current study presents the stagnation point flow of HNF flows about an orbiting sphere. The HNF is organized with the accumulation of aluminum alloys (AA70772 and AA7075) nanoparticles in the water. The HNF flow model equations are changed into the non-dimensional form of ODEs through the similarity variables and then numerically solved through the parametric simulation. It has been perceived that the significance of the rotation factor boosts the velocity curve, while the flow motion drops with the increasing numbers of AA7072 and AA7075 nanoparticles. Furthermore, the addition of AA7072 and AA70775 nano particulates in water lessens with the temperature profile. The energy distribution rate in case of hybrid nanoliquid enhances from 3.87 to 13.79%, whereas the mass dissemination rate enhances from 4.35 to 11.24% as the nanoparticles concentration varies from 0.01 to 0.03.