Safety Assessment Methodology Research Articles

Emerging Technology Integration - Artificial Intelligence (AI) and Machine Learning (ML) for Predictive Analysis for Safety and Toxicity Assessment in Environmental Toxicology

Environmental toxicology is facing unprecedented challenges due to the escalating complexity of environmental issues. Traditional methodologies for safety and toxicity assessment are struggling to keep pace with the rapid evolution of pollutants and their impacts on ecosystems and human health. In response to this pressing need, there has been a paradigm shift in the field towards the integration of Artificial Intelligence (AI) and Machine Learning (ML) techniques. This research article delves into the transformative potential of AI and ML in environmental toxicology, elucidating how these advanced computational tools offer promising solutions for predictive analysis. By leveraging vast datasets and sophisticated algorithms, AI and ML enable more efficient, accurate, and timely assessment of environmental risks. They empower researchers and policymakers to anticipate and mitigate potential hazards before they escalate into crises. This paper provides a comprehensive overview of the diverse applications of AI and ML in environmental toxicology, ranging from predictive modeling of chemical hazards to early detection of environmental threats. Furthermore, it highlights the potential of AI and ML to revolutionize decision-making processes in environmental management and policy formulation. By synthesizing vast amounts of data and identifying complex patterns and correlations, these technologies offer invaluable insights for crafting evidence-based policies and strategies to safeguard the environment and public health. This research article underscores the pivotal role of AI and ML in addressing the multifaceted challenges of environmental toxicology. Through their integration, we have the opportunity to enhance our understanding of environmental risks, optimize resource allocation, and ultimately, pave the way towards a more sustainable and resilient future.

Field Observations Of The Influence Of Infragravity Waves On Wave Overtopping At A Dike On A Shallow Foreshore

Infragravity (IG) waves are low-frequency waves (0.0033 Hz < f < 0.05 Hz) that exist: (i) being bound to the wave groups of high-frequency sea-swell (SS) waves (0.05 Hz < f < 1 Hz), (ii) generated by the moving breakpoint due to the groupiness of the SS waves (Bertin et al., 2018), and (iii) as free IG waves released from the SS wave groups and reflected from neighbouring coasts (Rijnsdorp et al., 2021). Offshore in deeper water (h/Hm0,o > 4, with h the water depth and Hm0,o the offshore significant wave height), IG waves become most apparent during storm conditions, but are still rather limited in wave height (order of a couple of cm). However, at the toe of coastal structures with a shallow foreshore depth (1 < ht/Hm0,o < 4, with ht the water depth at the toe), the energy of IG waves becomes more significant relative to the SS wave frequency band of the wave spectrum (Hofland et al., 2017), becomes equally important for very shallow foreshores (0.3 < ht/Hm0,o < 1), and even dominates SS wave energy for extremely shallow foreshore depths (ht/Hm0,o < 0.3). IG wave growth on mildly sloped shallow foreshores is a result of IG wave shoaling and SS wave energy transfer to IG waves via nonlinear wave-wave interactions (Bertin et al., 2018), and the relative growth of IG to SS wave energy is further aided by SS wave breaking. Coastal urban areas along the Belgian coast (and in other low-lying countries worldwide) rely on a hybrid beach-dike coastal defense system for protection against flooding. During design storm conditions, the nourished beach erodes to a very to extremely shallow foreshore in front of a low-crested impermeable sea dike. Wave overtopping at this type of structure has been shown to be affected by IG waves, based on physical (Altomare et al., 2016) and numerical modelling (Lashley et al., 2021) for shallow to extremely shallow foreshores. However, field observations of the influence of IG waves on wave overtopping have been scarce (van Gent and Giarusso, 2003) and the influence of free IG waves has not been investigated yet. Indeed, the amount of IG wave energy that is expected to arrive at the coastline, not only depends on IG waves naturally bound to the SS wave groups, but also on free IG waves generated offshore or locally reflected from the coast (edge waves). The Belgian continental shelf is characterized by the prevalence of offshore sandbanks (see Figure 1a), which might be an additional source of free IG waves, due to ss wave breaking on the shallow crest of those banks. These free IG waves are location specific and their existence can only be determined by field observations. Knowledge of the offshore boundary conditions with detailed IG wave information is indispensable for the correct prediction and modelling of surf zone hydrodynamics and beach morphodynamics (Fiedler et al., 2019), and the consequent wave overtopping on the dike. Simultaneous measurements of IG waves, offshore and on the beach-dike system during storm conditions together with wave overtopping has not been done before, as it is complex and needs a specific setup with high precision measurement equipment. In-situ measurements provide an invaluable dataset (i.e., no model nor scale effects) and are essential for validating safety assessment and design methodologies of coastal defense systems.

A Proposed Methodology for Assessment of Li-ion Cell Suitability and Safety for Suborbital Vehicle Applications

A Proposed Methodology for Assessment of Li-ion Cell Suitability and Safety for Suborbital Vehicle Applications

Advancing botanical safety: A strategy for selecting, sourcing, and characterizing botanicals for developing toxicological tools

Increases in botanical use, encompassing herbal medicines and dietary supplements, have underlined a critical need for an advancement in safety assessment methodologies. However, botanicals present unique challenges for safety assessment due to their complex and variable composition arising from diverse growing conditions, processing methods, and plant varieties. Historically, botanicals have been largely evaluated based on their history of use information, based primarily on traditional use or dietary history. However, this presumption lacks comprehensive toxicological evaluation, demanding innovative and consistent assessment strategies. To address these challenges, the Botanical Safety Consortium (BSC) was formed as an international, cross-sector forum of experts to identify fit-for purpose assays that can be used to evaluate botanical safety. This global effort aims to assess botanical safety assessment methodologies, merging traditional knowledge with modern in vitro and in silico assays. The ultimate goal is to champion the development of toxicity tools for botanicals. This manuscript highlights: 1) BSC's strategy for botanical selection, sourcing, and preparation of extracts to be used in in vitro assays, and 2) the approach utilized to characterize botanical extracts, using green tea and Asian ginseng as examples, to build confidence for use in biological assays.

Estimation of uncertainty in computation of importance factors and probability of undesirable events for safety-critical multi-unit systems, based on Binary Decisions Diagrams

This paper addresses current needs of the Multi-Unit Probabilistic Safety Assessment (MUPSA) methodology, which consists of a series of eight essential steps for conducting Probabilistic Safety Assessment (PSA) in the context of a multi-unit Nuclear Power Plant (NPP), co-located on a single site. The focus of this study revolves around one of the steps of the MUPSA methodology, which includes the examination of the importance factors and uncertainty analysis. Emphasizing the role of this step within MUPSA, the paper highlights the hypothesis and estimations made, along with the determination of system importance factors and failure frequency. To illustrate the practical application of these concepts, the paper presents three illustrative examples. The first example involves a 3-terminal reliability network, while the second example features an illustrative calculation applied to a system designed for potential use in a real NPP, compared to a Monte-Carlo simulation. Moreover, the second example involves the evaluation of a medium voltage distribution system (MVDS) designed to meet the auxiliary supply requirements of a nuclear power plant. This analysis is performed using a binary decision diagram (BDD), and the results derived from the BDD evaluation are then verified with those obtained through a Monte Carlo simulation for a comprehensive comparative analysis. Finally, an uncertainty analysis is achieved using a BDD reliability model, using the results of fault trees developed by National Company SN Nuclearelectrica S.A. (SNN), Department of Nuclear Safety, in the context of the Coordinated Research Project (CRP- I31031).

Hazard footprint of alternative fuel storage concepts for hydrogen-powered urban buses

Hydrogen mobility is a powerful strategy to fight climate change promoting the decarbonization of the transportation sector. However, the higher flammability of hydrogen in comparison with traditional fuels raises issues concerning the safety of hydrogen-powered vehicles, in particular when urban mobility in crowded areas is concerned. In the present study, a comparative analysis of alternative hydrogen storage concepts for buses is carried out. A specific inherent safety assessment methodology providing a hazard footprint of alternative hydrogen storage technologies was developed. The approach provides a set of ex-ante safety performance indicators and integrates a sensitivity analysis performed by a Monte Carlo method. Integral models for consequence analysis and a set of baseline frequencies are used to provide a preliminary identification of the worst-case credible fire and explosion scenarios and to rank the inherent safety of alternative concepts. Cryo-compressed storage in the supercritical phase resulted as the more hazardous storage concept, while cryogenic storage in the liquid phase at ambient pressure scored the highest safety performance. The results obtained support risk-informed decision-making in the shift towards the promotion of sustainable mobility in urban areas.

XBEACH IMPLEMENTATION IN THE NEW NATIONAL COASTAL FLOOD RISK ASSESSMENT FRAMEWORK FOR THE DUTCH COAST

Dunes and beaches protect large stretches of the Dutch coast against flooding from the sea. As prescribed by the Dutch Water Law, the Dutch dune coast is periodically assessed to ensure an acceptable level of flood risk in the hinterland. This safety assessment methodology is currently being renewed within the framework of the BOI program (Assessment and Design Instruments for flood defenses) to utilize the process-based storm impact model XBeach as replacement of the empirical dune erosion model DUROS+. The project consists of six steps: 1. XBeach model formulation improvements and model robustness, 2. XBeach calibration, 3. XBeach validation, 4. derivation of semi-probabilistic model input for the Dutch coast, 5. derivation of a failure definition and 6. implementing XBeach in a renewed flood risk assessment framework (Wilmink et al., 2020). The main goal of the project is to increase the accuracy of the flood risk assessment of dunes in the Netherlands by implementing XBeach as dune erosion model and develop a user-friendly GUI and guideline for the assessment framework.

Cell based models for validation of safety of cosmetic products and ingredients

The use of cosmetic products has grown many folds in recent years. The consumer and regulatory bodies are more concerned about the hazardous outcome of these products on skin health. The development of alternative and effective safety assessment methodologies to avoid animal testing is an urgent need due to restrictions and ethical considerations set by various regulatory bodies such as OECD, COLIPA, and BIS. The new integrated approaches like in-vitro assays (Cell-based and Cell-free assays) are indispensable for assessing the safety of cosmetic products. In-vitro testing systems provide advantages over animal testing as they are more cost-effective, and less time-consuming. In this article, we present the details of some of the important invitro assays that are routinely used by different laboratories for validation of the safety of cosmetic ingredients.

Safety of Streptococcus pyogenes Vaccines: Anticipating and Overcoming Challenges for Clinical Trials and Post-Marketing Monitoring.

Streptococcus pyogenes (Strep A) infections result in a vastly underestimated burden of acute and chronic disease globally. The Strep A Vaccine Global Consortium's (SAVAC's) mission is to accelerate the development of safe, effective, and affordable S. pyogenes vaccines. The safety of vaccine recipients is of paramount importance. A single S. pyogenes vaccine clinical trial conducted in the 1960s raised important safety concerns. A SAVAC Safety Working Group was established to review the safety assessment methodology and results of more recent early-phase clinical trials and to consider future challenges for vaccine safety assessments across all phases of vaccine development. No clinical or biological safety signals were detected in any of these early-phase trials in the modern era. Improvements in vaccine safety assessments need further consideration, particularly for pediatric clinical trials, large-scale efficacy trials, and preparation for post-marketing pharmacovigilance.

The Control and Comprehensive Safety Assessment of Heavy Metal Impurities (As, Pb, and Cd) in Green Tea Camellia sinensis (L.) Samples (Infusions) Available in Poland

Tea is the world’s most common drink after water, and the world’s annual sales exceed $43 billion, of which more than $11 billion is green tea (Camellia sinensis (L.)). Increasing evidence continues to show that green tea consumption and its ingredients have a variety of potential health benefits. The aim of the study was to control and assess the toxicological risk (TRA) of three heavy metals (As, Pb, and Cd) in infusions of green tea (n = 12) from Polish markets. We applied the method of inductive coupled plasma mass spectrometry (ICP-MS) to determine the selected heavy metal and designed a specific toxicological risk assessment with three crucial tiers. The first tier of our strategy was to determine the elements investigated (heavy metal impurities, µg/L). The second step was to estimate the weekly intake of green tea infusions (µg/week) based on weekly consumption. The third tier was to estimate the weekly intake per weight (µg/L/week/bw), based on the average weekly intake of green tea infusion per adult compared to the provisional weekly intake (PTWI) established by the FAO/WHO Joint Food Additives Expert Committee (JECFA). The levels of the investigated heavy metals occur at different levels in all of the investigated green tea infusions. The heavy metal profile indicated that As (0.0721–10.585 µg/L), Pb (0.386–1.695 µg/L), and Cd (0.126–0.346 µg/L) were present in all samples. Basic analysis of general content shows that As (average = 0.325 µg/L) was at a level similar to Cd (average = 0.214 µg/L). Surprisingly, the Pb content (average 0.891 µg/L) was approximately 2.75–4 times higher than that of As and Cd, respectively. The application of our proposed safety assessment methodology (three tiers) provides satisfactory results for regulatory purposes. The evaluation of the investigated heavy metals in all products analysed from green tea samples (infusions) showed that there were no health hazards to consumers due to weekly exposure. The results indicated that after drinking green tea infusions from Polish markets, the amount of investigated elements in weekly doses does not represent any health risks to consumers.

Climate change and hydrological dam safety: a stochastic methodology based on climate projections

ABSTRACT Climate change will likely increase the frequency and magnitude of extreme precipitation events and floods, increasing design peak flows that could lead to underestimates in current spillway capacity. Therefore, new methodologies for hydrological dam safety assessment considering climate change are required. This study presents a methodology that considers the impact of climate change on both inflow hydrographs and initial reservoir water levels. Moreover, the uncertainty in the procedure is assessed. The methodology is applied to the Eugui Dam in the River Arga catchment (Spain). An ensemble of 12 climate models is used. The results show an increase in the maximum reservoir water level during flood events and in the overtopping probability in the Representative Concentration Pathway 8.5 (RCP 8.5 scenario), especially in the 2071–2100 time window. The proposed methodology can be useful to assess future hydrological dam safety, fulfilling the requirements of recent regulations to consider the impact of climate change on dams.

Development of a data-driven simulation framework using physics-informed neural network

Because nuclear power plants (NPPs) are safety–critical systems with large sizes and high complexities, various methods have been developed to identify possible accidents and address potential risks. Accordingly, the probabilistic safety assessment (PSA) methodology is a prevalent nuclear risk assessment methodology. However, PSA has limitation in the consideration of dynamic interactions. As simulation methodologies develop, several simulation-based D-PSA methodologies have been developed, but there is a problem that the calculation speed and interaction of simulation cannot be considered.We propose a physics informed neural network (PINN) based data-driven simulation framework. The simulation framework comprises solution and model generators. The solution generator performs as the existing physical process model by using initial conditions, and boundary conditions. The model generator configures the most representative equation by using measurement data. Therefore, by sing the proposed framework, it is possible to construct a simulation methodology that not only has a fast simulation speed, but can also easily reflect system interactions.

Optimization of captain’s safety management

The article is devoted to the maritime safety issues in terms of captain’s management activity. Effective and safe management of captains can be achieved by identifying the importance of considering psychophysiological factors in the selection of seamen personnel, including captains, in conjunction with their managerial qualifications and high level of legal culture (knowledge and real willingness to strictly follow legal prescriptions and regulations), and by using a formal safety assessment method in relation to maritime crew management risks.
 The authors made a conclusion that the causes of accidents are rooted in the conflict between two main components: subjective (behavior – managerial decision) and objective (vessel and situation), in fact, the captain's personality (or behavior) complies with the requirements of the situation or technical condition of the vessel.
 Psychophysiological selection aims to identify abilities and qualities that appropriate professions, accompanied by significant neuropsychological strain, the severity of stressful situations, etc. It appeared that reaction disorder play a decisive role in one-third of all accidents, ergo, psychophysiological selection can reduce maritime casualties by 20-25%. In this respect, the application of the formal safety assessment method in combination with psychophysiological selection in the context of optimizing captain's safety management is proposed. The authors considered the professional selection of captains based on stable psychophysiological states and qualification while assessing the risks via formal safety assessment methodology as a dual basis of the maritime safety.
 The functional dependence of maritime safety on the policy of the shipping companies is defined: a) risk assessment, which allows to connect legal norms of safety directly with actions of the captain as much as possible, based on modelling of a situation; b) personnel activity, carried out on the basis of professional and managerial abilities of captains and taking into account the psychophysiological states; c) the level of legal culture (knowledge and strict adherence to safety rules and regulations) of the captain, who operates within the commercial, social and safety sectors, based on the complex of legal rules and regulations governing these sectors.

Update on Risk Criteria for Crude Oil Tanker Fleet

In recent years, the maritime trade of crude oil has suffered notable perturbations caused by the unbalanced relationship between supply and demand. The COVID-19 pandemic caused a drop in oil consumption in 2019, followed by a reduction in production in 2020. The seaborne transport of oil accounts for approximately 50–60% of all crude oil in world production. The crude oil market is a crucial regulator of the global economy and instabilities in this market have noticeable effects on collective risks. The immediate risks that the society see are the changes in the cost of living, which are followed by political uncertainties. Less visible are the risks that these uncertainties have on shipping companies and the level of management stability they have to maintain in order to keep seagoing safe. This paper presents an update on the overall state of risk management for the crude oil tanker fleet, evidenced by EMSA and other international marine organisations. The previous paper, entitled Safety Assessment of Crude Oil Tankers, which applied the methodology of the Formal Safety Assessment (FSA), was published in 2018 and covered the historical data related to the fleet size, accident reports, amount of oil spilled on sea and the economic value of the crude oil transport business. The particular focus of this paper is on the evolution of the risk acceptance criteria over the years and the difference in the predictions from 2018 to the present day. The effects of the pandemic on crude oil shipping are discussed through the changes in the risks. Three of them are analysed: PLL (potential loss of lives), PLC (potential loss of containment) and PLP (potential loss of property). The representation of the risk applies the F-N curves among the risk acceptance criteria lines observed for different tanker sizes. Among the three risks, the paper exposes the vulnerability of the loss of containment risk, where the strong economic impact of the oil trade outweighs the environmental concerns. In relation to the PLC, the paper proposes the approach of relating the oil spill acceptability with the spill quantity and ship revenue instead of to the cost of cleaning or the cost of environment recovery.

Methodology for the predictive assessment of the environmental safety of the use of ag-rochemicals by fertilizer seeding devices of combined potato planters

In the complex of environmental agricultural practices during of potatoes production an important place is given to the intrasoil local method of fertilizing. Technological systems for the application of this method operate as part of potato planting combined units. The use of automated technological systems for the implementation of an intrasoil local method of applying fertilizers will allow real-time dosed placement of foci of agrochemicals in those layers of the soil horizon that available for root system of plant. This will significantly reduce losses and increase the utilization rate of fertilizers while ensuring an acceptable level of environmental safety of their use and improving the working conditions of a operator. Therefore, given the random nature of the operating conditions of potato planting units, the development of an automated device for active control of the depth of placement of fertilizer foci in given horizons of the root layer the algorithm of which uses methods of predictive assessment of the state of the object is a very urgent task.

BOUNDARY CONDITIONS FORMATION OF THE STRESS-STRAIN STATE ANALYSIS OF CITY BUS BODIES

The presented research proposes a method of forming boundary conditions for the analysis of the Low-floor and Low-entry types of bus body frames under the static load conditions with appropriate measures to optimize the strength during bending and torsion modes of load. The assessment of the stress-strain state of the body frame is performed using the FEM, which is rightfully considered the most effective in the conditions of simulating the real-life behaviour of the metal structures under various load regimes. It is obvious that the main driving force behind the deep integration of FEM into the work process of developing the new bus models are the financial and time constraints of design and production. Besides the existing acute shortage of real tests of completed vehicles using strain gauges is the significant reason of various FEM-based methodologies for passive safety assessment and safety margin determination. From a mathematical point of view, the frame of the bus is a solid body, which in modelling can most strictly be described as a set of geometrically similar elements connected to each other in such a way that they form a structure as close as possible in shape to a real body. Stress-strain state of the bus body frame could be investigated for the different loading modes, but the most popular ones are the bending and torsion regimes, which are typical while the new bus model is designed and obtained. Furthermore, it’s definitely possible to judge, that the guarantee of sufficient safety under the terms of the UN-ECE Regulation (R66, R94, etc) is the height rigidity of the bus body frame during the bending and torsion tests. On the other hand, it is important to understand that the body frame must be equally strong and minimal in terms of material consumption, that’s why our goal is to investigate efficient boundary conditions formation which will provide as close to the natural tests’ behaviour as possible.

Improved formal safety assessment methodology using fuzzy TOPSIS for LPG-fueled marine engine system

In this study, a risk assessment of a Liquefied Petroleum Gas (LPG) marine engine system being developed for installation in the first LPG-powered ship in South Korea was performed and a new standard for a formal safety assessment (FSA) was proposed. Based on the FSA technique, hazards were identified through a failure mode and effect analysis (FMEA) in the first stage. An FMEA workshop was conducted to assess 110 components, and 89 hazards were identified. Of these, 19 failure modes of intolerable level were identified, and risk ranks were divided into four groups. Then, a more objective risk assessment was conducted using fuzzy set theory to compensate for the subjectivity of FMEA. Additionally, a technique for order performance by similarity to ideal solution (TOPSIS) was used to represent the risk rank of individual systems more precisely. By the second stage, risk ranks could be divided into 28 groups through the classification of a total of 89 hazards. Finally, risk control options were presented for high-ranking hazards according to the fuzzy TOPSIS results, and a cost-benefit analysis was performed. Consequently, the gross and net costs of averting a fatality were calculated as US $2.98 million and US $2.93 million, respectively. Through a cost-benefit analysis, the periodic exchange of main critical components was found to be in the range of economic criteria that could be recommended as a safety standard. The risk assessment technique proposed in this study allows a more objective and effective selection of critical hazards that necessitate risk control measures.

A safety assessment approach of the salvage based on salvor–cable–wreck coupled simulations

In order to accurately assess the safety of the whole salvage process, this paper presented a novel three-parameters safety assessment methodology on the basis of the time-domain analysis for a salvor–cable–wreck salvage system. A uniform criterion is eventually established by integrating different motion modes and comparable cases, which simplifies the description of the motion responses in the lifting operation. The water–soil–wreck interaction and salvor–cable interaction are respectively solved by the 8-degree finite element method and lumped mass method. Several groups of case studies under different sea states are numerically simulated and quantitatively assessed by utilizing the proposed method, out of the attention to the safety, stability, and energy efficiency in salvage engineering. According to the assessment scores, 30 and 150 deg could be selected as appropriate wave headings while the 180 deg wave direction is the safest. Also, small wave periods are found to be probable ideal sea states for sunken vessel salvage. The effect of the sunken object’s shape is relatively slight and mainly affects the stability of the salvor barge. Under larger wave heights or longer wave periods, the maximum tension and extra energy consumption of the lifting cables tend to increase.

Chemical Risk Assessment in a Selected Romanian Stainless Steel Processing Company

Abstract The production and use of chemicals are continuously increasing worldwide. For example, the global output of chemicals increased approximately 12 times between 1970 and 2020. The burden of disease attributable to exposure to chemicals is significant. World Health Organization estimates that globally, about 5 million deaths and 90 million disability - adjusted life years are attributable to occupational, environmental exposure and management. Public authorities and employers need access to reliable information on chemicals and practical, widely-accepted risk assessment methods in order to effectively control and minimize this threat. To support the management of chemical substances in small and mediumsized enterprises, the UK Health and Safety Executive developed the Control of Substances Hazardous to Health Essentials (COSHH Essentials), a control banding technique that determines the management method by assigning the qualitative work environment characteristics of the enterprises to a hazard and exposure prediction band. Qualitative tools were used for assessing the risk of these chemicals, creating solutions, and implementing control measures in various industrial fields. The present paper synthesizes the results of an extensive research study, dedicated to the evaluation of chemical risks within a Romanian company which has as object of activity the mechanical processing of steel laminates and their treatment by methods of electrochemical deposition of hard chromium / electrochemical nickel plating. The application of the simplified health, safety and environmental risk assessment methodology developed by the French National Security Research Institute (INRS) was considered to be the most appropriate in the preliminary phase of identifying and prioritizing the risks associated with chemicals used in technological processes in selected company. Based on the obtained results, the prevention and protection plan regarding the chemical risks was elaborated, the implementation of which led to the reduction of the workers’ exposure and to the minimization of the probability and severity of the potential consequences.

Application of external flood probabilistic safety assessment methodology to Prototype Fast Breeder Reactor

ABSTRACT This paper presents the methodology adopted, accident sequence analysis and salient results from the external flood probabilistic safety analysis exercise for Prototype Fast Breeder Reactor. The major steps performed are the probabilistic hazard estimation, fragility computation, system reliability modelling and risk quantification. The hazard analysis has been performed for rainfall, storm surge and tsunami as typically associated with a coastal site, from which correlation function relating flood level to the annual exceedance frequency is estimated. The fragility analysis of different safety systems is estimated by considering submergence mode of failure using step fragility functions. The secondary effects of flood such as debris impact, load falling and flood-induced sodium fires are not considered. The human reliability analysis of manual operations necessary for plant safety is done for the control room as well as onsite actions. The challenges encountered during the analysis, salient results and uncertainties involved are presented with inferences. Abbreviations: AHX: air heat exchanger; CDF: core damage frequency; EFPSA: external flood probabilistic safety assessment; EL: elevation levels; EOP: emergency operation procedure; ET: event tree; FT: fault tree; HRA: human reliability analysis; IE: initiating events; NPP: nuclear power plant; OGDHRS: operation grade decay heat removal system; PFBR: prototype fast breeder reactor; POT: peak over threshold; PSA: probabilistic safety assessment; PTHA: probabilistic tsunami hazard assessment; RY: reactor year; RCB: reactor containment building; RP: return period; SGDHRS: safety grade decay heat removal system; SSC: structures, systems and components