Sebastian Martorell

• Full Professor
• Head of Department at Polytechnic University of Valencia

A radiochemical procedure has been developed for the quantification of uranium and thorium isotopes in NORM samples from the ceramic industry, such as zirconium sands, zirconium flours, micronized zircon, pigments and personal aerosol filters. The method is based on a fusion pretreatment with borate salts, a separation with anion exchange resins an...

The nuclear industry is currently facing a significant demand for well-trained personnel. Due to the high market demand, it is essential to raise awareness among new target groups, including high school pupils and (pre-service) STEM teachers, about the potential and opportunities of pursuing a nuclear career. With this in mind, a new strategic part...

This paper presents a summary of theoretical and applied achievements in the field of integrated methods of nuclear safety analysis produced by Spain's nuclear safety community. These integrated methods combine deterministic as well as probabilistic tools and include the approaches termed "Extended Best-Estimate Plus Uncertainty" (E-BEPU), dynamic...

The development of Probabilistic Safety Analysis, which began in Spain in 1986, is based on the document "Integrated Program on Development and Use of Probabilistic Safety Analysis in Spain" adopted by the Spanish regulatory body. A second edition of this document in 1998 considered the activities needed to apply its principles in different fields....

This paper reviews the published terminology, mathematical models, and the possible approaches used to characterise the risk of foodborne chemical hazards, particularly pesticides, metals, mycotoxins, acrylamide, and polycyclic aromatic hydrocarbons (PAHs). The results confirmed the wide variability of the nomenclature used, e.g., 28 different ways...

Best-Estimate Plus Uncertainty (BEPU) nuclear safety analysis is an approach widely used in the field of nuclear engineering and reactor safety assessment. It aims to provide a more realistic assessment of reactor safety by considering a combination of best-estimate models and the quantification of the uncertainty of the input and code data. The Sp...

La protección radiológica es una actividad multidisciplinar que tiene como finalidad la protección de las personas y del medio ambiente contra los efectos nocivos de la exposición a radiaciones ionizantes (CSN 2023). Esta actividad está relacionada con varios de los Objetivos de Desarrollo Sostenible (ODS) de la Agenda 2030, como el ODS 3 (salud y...

To reach a Net Zero Emission scenario, on 1st January 2022 the European Union (EU) declared nuclear and gas as transitional activities under strict safety conditions. A central challenge is that many nuclear reactors in operation are close to or have reached their design life, so that, it is required to demonstrate the influence of equipment ageing...

Risk-informed decision making permits a more effective water safety management. In this framework, this article introduces the rationale and proposes a new approach to carry out a quantitative risk assessment along the water chain, from river source to tap water, by integrating predictive modelling combined with event-tree and fault-tree techniques...

The aim of this work is to present the rationale, formulation, and application of the probability of exceedance (POE) as a metric capable of characterizing public health risks due to exposure to non-threshold chemical hazards in food. One of the main advantages of this metric is that it complements the information provided by the MOE and supports r...

This paper analyses the relationship between the evolution of occupational health indicators, i.e. frequency rate (FR), severity rate (SR) and days lost per accident (DLA), and the performance of relevant influencing factors related to the labour market, the productivity structure and the economy using regression shrinkage methods: the Lasso, Elast...

This paper presents a three-stage protocol for gross alpha and gross beta evaluation in water samples in emergencies. The novelty of this approach is the great level of detail for its application in this type of sample, following the criteria proposed in well-established safety guidelines. This protocol makes use of a rapid method adapted from diff...

This paper contains the fundamentals and a comparison of different alternatives in the context of risk-informed surveillance requirements that consider the full effects of implementing the maintenance rule. A case study is included to demonstrate the performance of the different alternatives, which focus on a motor-operated valve and make use of an...

In this work the fundamentals and application results of an uncertainty analysis of a loss of coolant and loss of cooling accident in a spent fuel pool are presented. The spent fuel pool was modeled with TRACE V5.0 Patch 5 using a VESSEL 3D component in Cartesian coordinates. A more detailed nodalization was necessary as compared with a previous st...

One of the problems of measuring high radioactivity in an emergency scenario is the fact that the detector can become saturated or reach a measuring dead time too high to give reliable results, which means repeating the measurement in different conditions with the associated delay in obtaining the results and the laboratory workers' risk of exposur...

This study describes a rapid method for sequential determination of uranium and plutonium isotopes in soil and sediment samples and its application to the study of Anthropocene sedimentary records. Different pretreatment methods have been tested (open-vessel digestion, borate salts fusion and NaOH salt fusion) achieving the complete dissolution of...

Occupational accidents pose considerable burdens to people, businesses and society in general. The analysis of trends in the evolution of time series related to occupational health indicators is an important tool to help determining the extent to which economic or structural changes in the sectors of industry, agriculture, construction and services...

This study describes a rapid and novelty method for radiostrontium determination in aerosol filters and vegetation based on the use of plastic scintillation resins (PS resin), which combines the separation and measurement preparation into a single step. The optimization of the pre-treatment steps and the use of PS resin allows a simplification of t...

According to World Health Organization (WHO), the radon is the second leading cause of lung cancer. This work is centered on a Waste Water Pre-Treatment Plant (WWTP) with radon concentration above Spanish action level (600 Bq per cubic meter). The authors have developed a novelty method based on gamma and alpha spectrometry to measure the radon equ...

Environmental samples analyzed in gamma spectrometry laboratories usually contain natural radionuclides such as ²³⁸U and ²³²Th. Using gamma spectrometry techniques is possible to estimate the activity of these radionuclides by measuring the gamma emissions of radionuclides belonging to their decay chain. Nonetheless, some of these radionuclides emi...

Los actuales planes de estudio del Espacio Europeo de Educación Superior (EEES) incluyen una serie de competencias transversales y específicas que deben adquirir los alumnos al finalizar las distintas titulaciones. A través del proceso de acreditación “Accreditation Board for Engineering and Technology” (ABET), llevado a cabo en algunas titulacione...

This work is focused on studying the capabilities of different Monte Carlo tools to complement the Full Energy Peak Efficiency (FEPE) calibration procedures of the Environmental Radioactivity Laboratory of the Universitat Politècnica de València, UPV. In this frame, detailed models of a High Purity Germanium detector have been implemented using MCN...

Although in risk screening of equipment structures, systems and components, changes can be accomplished directly using RG 1.174, a plant change may also include changes to human actions. Human reliability analysis is an integral part of probabilistic safety assessment modeling. Using best estimate codes can identify unknown accident sequences as we...

Gross alpha (Aα) and gross beta activities (Aβ) were measured weekly in the airborne of the Universitat Politècnica de Valencia campus (in the east of Spain) during the period 2009-2015 (7 years). The geometric mean values of weekly Aα and Aβ were 0.53·10-4 Bq m-3 and 5.77·10-4 Bq m-3, respectively; with an average ratio Aα/Aβ of 0.097. This study...

The safety analysis of nuclear power plant is moving toward a realistic approach in which the simulations performed using best estimate computer codes must be accompanied by an uncertainty analysis, known as the Best Estimate Plus Uncertainties approach. The most popular statistical method used in these analyses is the Wilks’ method, which is based...

One can find many reliability, availability, and maintainability (RAM) models proposed in the literature. However, such models become more complex day after day, as there is an attempt to capture equipment performance in a more realistic way, such as, explicitly addressing the effect of component ageing and degradation, surveillance activities, and...

This study describes a new and rapid procedure for radiostrontium determination in milk samples based on the use of plastic scintillation resins (PS resins). The proposed method reduces the time of analysis by at least 2 h by combining separation and measurement preparation into a single step and optimizing the pre-treatment steps. The method is ro...

This paper discusses system codes benchmarking activities on an ASTRID-like heterogeneous fast core under a representative design basis accident condition: the unprotected loss of flow accident (ULOF). The paper provides evidence that all the system codes used in this exercise are capable to simulate the transient behavior of heterogeneous SFR core...

The Nuclear Energy Agency auspices simulation of experiments in different facilities under several programs. One on them consisted of performing a counterpart test between ROSA/LSTF and PKL facilities, with the main objective of determining the effectiveness of late accident management actions in a small break loss of coolant accident. The results...

Después de la implantación de los nuevos Grados y Másteres, la Universitat Politècnica de València (UPV) publicó una lista de competencias genéricas para agrupar los diferentes perfiles competenciales. Esta lista consta de un total de 13 competencias que deben trabajarse y evaluarse en las diferentes materias. En este marco, se debe mejorar la coor...

Forecasting the 7Be air concentration is a target value in analyzing fluctuations that could reveal important information on the motions of atmospheric air masses. In this study we first propose a Seasonal Autoregressive Integrated Moving Average (SARIMA) model with a historical data time window of eight years (2007-2014) to forecast 7Be activity....

The International Atomic Energy Agency (IAEA) produced guidance on the use of Deterministic Safety Analysis (DSA) for the design and licensing of Nuclear Power Plants (NPPs) in “DSA for NPP Specific Safety Guide, No. SSG-2”, which proposes four options for the application of DSA. Option 3 involves the use of Best Estimate codes and data together wi...

The reliability, availability and maintainability (RAM) modelling of safety equipment has long been a topic of major concern. Some RAM models have focussed on explicitly addressing the effect of component degradation and surveillance and maintenance policies, searching for an optimum level of the safety component RAM by adjusting surveillance and m...

The concept of Food Safety Margin (FSM) was introduced in microbiological risk analysis as an alternative approach to risk characterization within the informed-risk decision-making process. Its aim was to verify compliance with food safety objectives by assessing the effects of uncertainties. This paper describes the fundamentals and develop a new...

We analyze in this paper a Waste Water Pre-Treatment Plant (WWTP) located at the Mediterranean coast with air radon concentration above Spanish action level (600 Bq per cubic meter). This paper presents a method for radon equilibrium determination by gamma spectrometry measuring of the radon progeny concentrations in the air, in order to estimate W...

Nuclear power plant risk has to be quantified in full power and in other modes of operation. This latter situation corresponds to low power and shutdown modes of operation in which the residual heat removal (RHR) system is required to extract the heat generated in the core. These accidental sequences are great contributors to the total plant risk....

Be is a cosmogenic radionuclide widely used as an atmospheric tracer, whose evaluation and forecasting can provide valuable information on changes in the atmospheric behavior. In this study, measurements of ⁷Be concentrations were made each month during the period 2007–2015 from samples of atmospheric aerosols filtered from the air. The aim was to...

There is an attempt nowadays to provide a more comprehensive and realistic safety assessment of design and operation of Nuclear Power Plants. In this context, innovative approaches are being proposed for safety assessment of nuclear power plants design including both design basis conditions and design extension conditions. An area of research aims...

One of the goals of Generation IV reactors is to increase safety from those of previous generations. Different research platforms have been identified the need to improve the reliability of the simulation tools to ensure the capability of the plant to accommodate the design basis transients established in preliminary safety studies. The paper descr...

Be air concentrations were measured at the UniversitatPolitècnica de Valencia campus (in the east of Spain) during the period 2007–2014. The mean values of monthly ⁷Be concentrations ranged from 2.65 to 8.11 mBq/m³, showing significant intra and interannual variability. A seasonal-trend decomposition methodology was applied to identify the trend-cy...

The aim of this paper was to calculate the True Coincidence Summing Correction Factors (TSCFs) for an HPGe coaxial detector in order to correct the summing effect as a result of the presence of (88)Y and (60)Co in a multigamma source used to obtain a calibration efficiency curve. Results were obtained for three volumetric sources using the Monte Ca...

There are many models in the literature that have been proposed in the last decades aimed at assessing the reliability, availability and maintainability (RAM) of safety equipment, many of them with a focus on their use to assess the risk level of a technological system or to search for appropriate design and/or surveillance and maintenance policies...

The safety verification of nuclear systems can be done by analyzing the outputs of Best-Estimate Thermal-Hydraulic (BE-TH) codes, which allow predicting the system response under safe and accidental conditions with greater realism as compared to conservative TH codes. In this case, it is necessary to quantify and control the uncertainties in the an...

This paper presents the fundamentals and examples of application of the relationship between the most commonly used occupational accident indicators in Spain and risk components, which could be therefore used for the risk-informed decision-making on occupational safety and health within a risk-based management context. Since there are many differen...

Experimental facilities are scaled models of commercial nuclear power plants, and are of great importance to improve nuclear power plants safety. Thus, the results obtained in the experiments undertaken in such facilities are essential to develop and improve the models implemented in the thermal-hydraulic codes, which are used in safety analysis. T...

This paper presents an approach for the evaluation of risk impact of Surveillance Requirement changes addressing identification, treatment and analysis of uncertainties in an integrated manner, which is intended to be used in an optimization context. It is also presented an example of application of the methodology to study a SF change of the React...

Safety (S) improvement of industrial installations leans on the optimal allocation of designs that use equipment that is more reliable and testing and maintenance activities to assure a high level of reliability, availability and maintainability (RAM) for their safety-related systems. However, this also requires assigning a certain amount of resour...

This paper proposes a new approach to Ageing Probabilistic Safety Assessment (APSA) modelling, which is intended to be used to support risk-informed decisions on the effectiveness of maintenance management programs and technical specification requirements of critical equipment of Nuclear Power Plants (NPP) within the framework of the Risk Informed...

La asignatura “Control de Riesgos en Instalaciones Industriales y Agroalimentarias”pertenece al Master de Prevencion de Riesgos Laborales de la UPV y en ella se analiza la normativa de seguridad aplicable a instalaciones de industrias genericas y agroalimentarias. La asignatura la cursan actualmente unos 18 alumnos de perfil multidisciplinar, inclu...

Over the last decade, risk analysis has gradually been introduced as a tool to make decisions about food safety policies. In this framework, the ALOP (Appropriate Level of Protection) concept, which can be seen as a statement of the degree of public protection that should be attained in a country, was introduced. In addition, FSO (Food Safety Objec...

(222)Rn is a naturally occurring gas created from the decay of (226)Ra. The long-term health risk of breathing radon is lung cancer. One particular place where indoor radon concentrations can exceed national guidelines is in wastewater treatment plants (WWTPs) where treatment processes may contribute to ambient airborne concentrations. The aim of t...

Environmental radioactivity monitoring includes the determination of radionuclides in foods since they are an important way of intake of radionuclides to the human organism. Moreover, knowledge of the levels of radionuclides in foodstuffs will inform about the environmental radioactivity background permitting to control possible contamination due t...

Nuclear policies have experienced an important change since Fukushima Daiichi nuclear plant accident and the safety of spent fuels has been in the spot issue among all the safety concerns. At many countries, the spent fuel of nuclear power plants is not reprocessed so it has to be stored inside the facilities, normally in pools. As nuclear power pl...

This paper presents an approach and an example of application for the evaluation of risk impact of changes to Completion Times within the License Basis of a Nuclear Power Plant based on the use of the Probabilistic Risk Assessment addressing identification, treatment and analysis of uncertainties in an integrated manner. It allows full development...

This paper presents a three steps based approach for the evaluation of risk impact of changes to Surveillance Requirements based on the use of the Probabilistic Risk Assessment and addressing identification, treatment and analysis of model and parameter uncertainties in an integrated manner. The paper includes also an example of application that fo...

Nowadays, there is an increasing demand for Condition Based Maintenance (CBM) activities as time-directed maintenance is observed to be inefficient in many situations. CBMis a maintenance strategy based on collecting information concerning the working condition of equipment, such as vibration intensity, temperature, pressure, etc., related to the s...

Nuclear Power Plant safety analysis is mainly based on the use of best estimate (BE) codes that predict the plant behavior under normal or accidental conditions. As the BE codes introduce uncertainties due to uncertainty in input parameters and modeling, it is necessary to perform uncertainty assessment (UA), and eventually sensitivity analysis (SA...

Dosimetría de la Radiación is a subject to be coursed in the Master de Seguridad Industrial y Medioambiente. One of the main objectives of this subject is to provide the appropriate tools to the students for the estimation of external and internal dose. The course is organized with many practical sessions, in which the students use calculation tool...

A specific feature of wind power generation is the stochastic behavior of wind velocity which determines the energy produced, and also influences the turbine degradation process due to the stochastic load suffered by the wind turbine. Thus, wind turbines present a degradation process more complex than the equipment that work under stationary condit...

Nowadays, there is an increasing demand for Condition Based Maintenance (CBM) activities as time-directed maintenance are observed to be inefficient in many situations. CBM is a maintenance strategy based on collecting information concerning the working condition of equipment, such as vibration intensity, temperature, pressure, etc., related to the...

This paper presents the optimization of design and test policies of safety instrumented systems using MooN voting redundancies by a multi-objective genetic algorithm. The objectives to optimize are the Average Probability of Dangerous Failure on Demand, which represents the system safety integrity, the Spurious Trip Rate and the Lifecycle Cost. In...

Maintenance planning is a subject of concern to many industrial sectors as plant safety and business depend on it, and can be formulated in terms of a multi-objective optimization problem where reliability, availability, maintainability and cost act as decision criteria and surveillance test and maintenance strategies act as decision variables. Usu...

The loss of the residual heat removal system in mid-loop conditions may occur with a nonnegligible contribution to the plant risk, so the analysis of the accidental sequences and the actions to mitigate the accident are of great interest in shutdown conditions. In order to plan the appropriate measures to mitigate the accident is necessary to under...

The storage requirements of Spent Fuel Pools have been analyzed with the purpose to increase their rack capacities. In the past, the thermal limits have been mainly evaluated with conservative codes developed for this purpose, although some works can be found in which a best estimate code is used. The use of best estimate codes is interesting as th...

Many industrial sectors are concerned on developing optimal maintenance planning because of the importance of maintenance on the economy and safety. Traditionally, the maintenance planning is formulated in terms of a multi-objective optimization problem where reliability, availability, maintainability and cost act as decision criteria and surveilla...