Spanish Nuclear Power Plants Research Articles

Qualification Of Inspection Systems In Nuclear Power Plants. Looking For Excellence

Inspection reliability is an area of growing interest. In particular, in certain industrial sectors involving critical structures, such as nuclear power plants for energy generation, reliability of Non-Destructive Examinations (NDE) has received special attention since more than 40 years. Many initiatives and projects (PISC, EPRI NDE, ENIQ, etc.) developed and generated new findings and results. In addition, the inspection systems are regularly optimized for improving the NDE reliability as much as possible. In the early 1990s, the European Network for Inspection Qualification (ENIQ) continued the PISC NDE reliability research and, few years later, issued the European Methodology for Qualification of Non-Destructive Testing. The methodology considers the NDE system follows the modular model of reliability as well as complementary tasks to address human factors issues. Then, every country develops his own methodology based on the existing legal requirements and the ENIQ Methodology. This is the case of Spain, in which the CSN (the Nuclear Safety Body) requires the qualification of inspection systems before their application in the Nuclear Power Plants (NPP). This paper describes the main characteristics of the Spanish Methodology as well as examples to facilitate the understanding of the ideas behind the approach that currently applied in the Spanish NPPs since the mid-2000s.

Optimization of prevention and mitigation of severe accidents through Research: Major outcomes and outlook of the Spanish programme

Severe accidents research activities in Spain have grown substantially since the Fukushima-Daiichi accident. Most of these research activities have been conducting by a few organizations (national research center and academia) with the support of the Regulatory Authority, utilities and engineering companies. A great number of these activities were conducted in the analytical field and their main outcomes are contributing to a better understanding of severe accident phenomena (i.e., pool scrubbing; combustible gas distribution and combustion; fission products transport; etc.) and the efficiency of severe accident management actions (i.e., FLEX; PARs; activation of safety systems, long-term measures; etc.). The national framework set between researchers and end-users (regulators and utilities) is improving the safety of the Spanish nuclear power plants and allows for the assimilation of the research results by the nuclear industry.

NUCLEAR WASTE MANAGEMENT IN SPAIN: ANALYSIS OF THE CURRENT SITUATION AND ALTERNATIVE STRATEGIES

Centralized Temporary Storage Facility (CTS) is an industrial facility designed to store spent fuel (SF) and high level radioactive waste (HLW) generated at Spanish nuclear power plants (NPP) in a single location. At the end of 2011, the Spanish Government approved the installation of the CTS in the municipality of Villar de Cañas in Cuenca. This approval was the outcome of a long process of technical studies and political decisions that were always surrounded by great social rejection. After years of confrontations between the different political levels, with hardly any progress in its construction, this infrastructure of national importance seems to have been definitively postponed. The present research analyzes the management strategy of SF and HLW in Spain, as well as the alternative strategies proposed, taking into account the current schedule foreseen for the closure of the Spanish NPPs. In view of the results obtained, it is difficult to affirm that the CTS will be available in 2028, with the possibility that its implementation may be delayed to 2032, or even that it may never happen, making it necessary to adopt an alternative strategy for the management of GC and ARAR in Spain. Among the different alternatives, the permanence of the current Individualized Temporary Stores (ITS) as a long-term storage strategy stands out, and even the possibility of building several distributed temporary storage facilities (DTS) in which to store the SF and HLW from several Spanish NPP. Keywords: nuclear waste, storage, nuclear power plants.

Social Media: useful for high-risk industries? A study of nuclear energy in Spain

Social Media has become an unquestionable communicative tool for most organizations. Companies want to participate in the conversation on the network for various purposes: attracting new customers, promoting their products, exalting their brand, searching for prescribers, etc. However, those corporations that belong to risk sectors –as is the case of nuclear power plants– show initial suspicion because they consider that new forms of communication contribute to encouraging criticism of their business model, producing a deterioration in their image. The methodology used in this research is based on three pillars: a review of the literature on CSR, corporate reputation, Social Media and Nuclear Communication; exploration of Social Media in search of official profiles of nuclear power plants; and interviews with those responsible for communicating atomic plants to know their perception in the use of these supports. Spanish nuclear power plants do not actively use Social Media. These facilities rely on monologic communication tools and tactics, although they need dialogue for acceptance and long-term operation. Social Media are essential tools for risk sectors: to disseminate the science they make, to collect feedback and respond to criticism, and to seek consensus.

Safety Culture in the Spanish Nuclear Power Plants through the Prism of High Reliability Organization, Resilience and Conflicting Objectives Theories

Safety culture is the result of values, attitudes, and perceptions of the members of an organization that prioritize safety over competing goals. Previous research has shown the impact that organizational aspects can have in safety performance. Under the prism of the theoretical approaches from the high reliability organizations theory (HROT), resilience engineering (RE), and conflicting objectives perspective, this study was aimed at describing the overall main safety culture traits of the Spanish nuclear power plants, as well as identifying particularities associated with subcultures. For this purpose, a statistical analysis of safety culture surveys and behavioral anchored rating scales (BARS), handed over to all the operating Spanish nuclear power plants, was carried out. Results reveal that safety is a recognized value that prevails over production, there is a high degree of standardization, power plants are better prepared to organize plans and strategies than to adapt and cope with the needs of a crisis, and there is a critical and fragmented perception about the processes of resources allocation. Findings also identify that sociodemographic aspects, such as work location and contractual relationship, seem to be shaping differentiated visions. Several safety implications linked to the results are discussed.

Minimizing the Standard Deviation of the Thermal Load in the Spent Nuclear Fuel Cask Loading Problem

The paper assumes that, at the end of the operational period of a Spanish nuclear power plant, an Independent Spent Fuel Storage Installation will be used for long-term storage. Spent fuel assemblies are selected and transferred to casks for dry storage, with a series of imposed restrictions (e.g., limiting the thermal load). In this context, we present a variant of the problem of spent nuclear fuel cask loading in one stage (i.e., the fuel is completely transferred from the spent fuel pool to the casks at once), offering a multi-start metaheuristic of three phases. (1) A mixed integer linear programming (MILP-1) model is used to minimize the cost of the casks required. (2) A deterministic algorithm (A1) assigns the spent fuel assemblies to a specific region of a specific cask based on an MILP-1 solution. (3) Starting from the A1 solutions, a local search algorithm (A2) minimizes the standard deviation of the thermal load among casks. Instances with 1200 fuel assemblies (and six intervals for the decay heat) are optimally solved by MILP-1 plus A1 in less than one second. Additionally, A2 gets a Pearson’s coefficient of variation lower than 0.75% in less than 260s CPU (1000 iterations).

Nuclear engineering and technology transfer: The Spanish strategies to deal with US, french and german nuclear manufacturers, 1955–1985

We analysed the process of construction and connection to the electrical grid of four Spanish nuclear power plants with different financial and technological foreign partners: those of Zorita (PWR by Westinghouse), Garoña (BWR by General Electric) and Vandellós I (GCR by EDF) (belonging to the first generation of atomic plants and producing electricity from 1969–72) and that of Trillo I (PWR by KWU, connected in 1988). These four examples allow us to observe how the learning curve of nuclear engineering and the acquisition of skills by Spanish companies evolved. Progressively the domestic industry achieved higher levels of participation, fostered by the Ministry of Industry and Energy. When the atomic plants under construction were paralysed by the nuclear moratorium of 1984, and several other projects were abandoned by the utilities along the way, Spain had developed an industrial sector around the fabrication of service components and engineering for nuclear power plants to compete internationally.

Spanish validation of the mindful organizing scale: A questionnaire for the assessment of collective mindfulness

IntroductionMindful organizing (also known as collective mindfulness) is a team level construct that is said to underpin the principles of high-reliability organizations (HROs), as it has shown to lead to almost error-free performance. While mindful organizing research has proliferated in recent years, studies on how to measure mindful organizing are scarce. Vogus and Sutcliffe (2007) originally validated a nine-item “Mindful Organizing Scale” but few subsequent validation studies of this scale exist. The present study aimed to validate a Spanish version of the Mindful Organizing Scale. MethodThe sample included 47 teams (comprising of a total of 573 workers with an average team size of 12.19) from a Spanish nuclear power plant. A confirmatory factor analysis (CFA), reliability analysis, and an analysis of aggregation indices were carried out. A correlation analysis and CFA were used to further validate the scale in terms of its distinctiveness from, and relationship with, other team-related variables such as safety culture, team safety climate, and team learning. Finally, evidence of criterion-related validity was collected by testing the incremental validity of the mindful organizing scale in the association with various workplace safety outcomes (safety compliance and safety participation). ResultsThe results confirmed a unidimensional structure of the scale and indicated satisfactory internal consistency. Aggregation of the scores to the team level was justified while significant positive correlations between mindful organizing and other team-related variables (safety culture, team safety climate, team learning) were found. Moreover, mindful organizing showed distinctiveness from safety culture, team safety climate and team learning. Finally, incremental validity of the scale was supported, as it shows to be associated with safety compliance and safety participation above and beyond other related constructs. ConclusionsThe Spanish version of the Mindful Organizing Scale has shown to be a valid and reliable scale that can be used to measure mindful organizing. ContributionsThe validation of the unidimensional Spanish version of Vogus and Sutcliffe’s (2007) Mindful Organizing Scale provides researchers and practitioners with a reliable and valid tool to use in Spanish speaking organizations to measure mindful organizing, which has been shown to result in more reliable performance. Theoretically, this study offers four contributions. Firstly, it validates a scale that operationalizes the ‘mindful organizing’ construct in a traditional high-reliability organization (nuclear power plant) which has never been done before. Secondly, it offers evidence that a mindful organizing scale can be validated in a new cultural context and language (Spanish) to any of the previous studies done before it. Thirdly, it adds to our understanding of mindful organizing’s nomological network by distinguishing it from other team and safety-related variables. Lastly, it builds on current research showing sound psychometric properties of a one-dimensional, quantitative measure of mindful organizing.

Learning by Doing: The First Spanish Nuclear Plant

In the nuclear sector, turnkey projects can be considered an investment in obtaining information through “learning by doing” to capture rents from the next generation of reactors. As the first U.S. turnkey export project, the first Spanish nuclear power plant served that purpose and paved the way for the subsequent growth of the nuclear sector, for both Spanish and U.S. firms. Making use of archival material, we analyze the networks created by the government, experts, and business leaders, which sought to obtain, accumulate, and learn from the scarce and conflicting information about atomic technology that was available at the time. We also discern how firms on both sides of the Atlantic acquired and perfected the specific capabilities required to build a commercial nuclear reactor.

Probabilistic Prognosis of Environmental Radioactivity Concentrations due to Radioisotopes Discharged to Water Bodies from Nuclear Power Plants.

Due to their very low values, the complexity of comparing the contribution of nuclear power plants (NPPs) to environmental radioactivity with modeled values is recognized. In order to compare probabilistic prognosis of radioactivity concentrations with environmental measurement values, an exercise was performed using public data of radioactive routine discharges from three representative Spanish nuclear power plants. Specifically, data on liquid discharges from three Spanish NPPs: Almaraz, Vandellós II, and Ascó to three different aquatic bodies (river, lake, and coast) were used. Results modelled using generic conservative models together with Monte Carlo techniques used for uncertainties propagation were compared with values of radioactivity concentrations in the environment measured in the surroundings of these NPPs. Probability distribution functions were inferred for the source term, used as an input to the model to estimate the radioactivity concentrations in the environment due to discharges to the water bodies. Radioactivity concentrations measured in bottom sediments were used in the exercise due to their accumulation properties. Of all the radioisotopes measured in the environmental monitoring programs around the NPPs, only Cs-137, Sr-90, and Co-60 had positive values greater than their respective detection limits. Of those, Sr-90 and Cs-137 are easily measured in the environment, but significant contribution from the radioactive fall-out due to nuclear explosions in the atmosphere exists, and therefore their values cannot be attributed to the NPPs. On the contrary, Co-60 is especially useful as an indicator of the radioactive discharges from NPPs because its presence in the environment can solely be attributed to the impact of the closer nuclear facilities. All the modelled values for Co-60 showed a reasonable correspondence with measured environmental data in all cases, being conservative in two of them. The more conservative predictions obtained with the models were the activity concentrations in the sediments of a lake (Almaraz) where, on average, values two times higher were obtained. For the case of rivers (Ascó), calculated results were adequately conservative—up to 3.4 times on average. However, the results for coasts (Vandellos II) were in the same range as the environmental measurements, obtaining predictions that are only—at maximum—1.1 times higher than measured values. Only for this specific case of coasts could it be established that the models are not conservative enough, although the results, on average, are relatively close to the real values.

Freshwater for Cooling Needs: A Long-Run Approach to the Nuclear Water Footprint in Spain

From the invention of the steam engine to the present, water has represented a significant input to the energy system, although this has been mostly ignored in the literature. In Spain, the most arid country in Europe, studies about water footprint typically just consider domestic, agricultural and industrial water uses, but water requirements for the electricity sector are omitted despite our dependence on thermal power. It has been demonstrated that for each available cooling technology, nuclear needs and consumption of water tend to be larger per MWh generated. We calculate a first approximation to the Spanish nuclear water footprint from 1969 to 2014. Our results show that while water consumed by Spanish nuclear power plants are around 3 m3 per capita/year, water withdrawals per capita/year are around 70 m3. Moreover, our analysis allows extracting conclusions focusing on a River Basins approach. What is the water impact of our nuclear power plants? Will water limit our energy future? These are some of the issues at stake.

The Safety Culture Enactment Questionnaire (SCEQ): Theoretical model and empirical validation

This paper presents the Safety Culture Enactment Questionnaire (SCEQ), designed to assess the degree to which safety is an enacted value in the day-to-day running of nuclear power plants (NPPs). The SCEQ is based on a theoretical safety culture model that is manifested in three fundamental components of the functioning and operation of any organization: strategic decisions, human resources practices, and daily activities and behaviors. The extent to which the importance of safety is enacted in each of these three components provides information about the pervasiveness of the safety culture in the NPP. To validate the SCEQ and the model on which it is based, two separate studies were carried out with data collection in 2008 and 2014, respectively. In Study 1, the SCEQ was administered to the employees of two Spanish NPPs (N=533) belonging to the same company. Participants in Study 2 included 598 employees from the same NPPs, who completed the SCEQ and other questionnaires measuring different safety outcomes (safety climate, safety satisfaction, job satisfaction and risky behaviors). Study 1 comprised item formulation and examination of the factorial structure and reliability of the SCEQ. Study 2 tested internal consistency and provided evidence of factorial validity, validity based on relationships with other variables, and discriminant validity between the SCEQ and safety climate. Exploratory Factor Analysis (EFA) carried out in Study 1 revealed a three-factor solution corresponding to the three components of the theoretical model. Reliability analyses showed strong internal consistency for the three scales of the SCEQ, and each of the 21 items on the questionnaire contributed to the homogeneity of its theoretically developed scale. Confirmatory Factor Analysis (CFA) carried out in Study 2 supported the internal structure of the SCEQ; internal consistency of the scales was also supported. Furthermore, the three scales of the SCEQ showed the expected correlation patterns with the measured safety outcomes. Finally, results provided evidence of discriminant validity between the SCEQ and safety climate. We conclude that the SCEQ is a valid, reliable instrument supported by a theoretical framework, and it is useful to measure the enactment of safety culture in NPPs.

CAE—The Spanish Emergency Support Center: A Centralized and Shared Emergency Support Service for Beyond Design Basis Events

The Spanish nuclear power generation industry proposed the development of an external Emergency Support Center as one of the measures to strengthen the nuclear safety and Emergency Preparedness and Response, as a consequence of the stress test developed after the Fukushima accident. The CAE project was carried out to define and establish a centralized service composed of intervention equipment and specialized personnel in the framework of an Emergency Support Center shared among all the Spanish nuclear power plants (NPPs). The emergency support service aims to strengthen the NPP emergency capabilities, by integrating with the Emergency Response Organization (ERO) of plants. This service successfully developed preoperational tests at each one of the Spanish NPPs in 2014. With these tests, the development of the different aspects that make up the Emergency Support Center service, at every Spanish NPP, was validated in four stages: (1) CAE mobilization in less than 24 hrs, (2) equipment deployment to its final location in the plant, (3) checking the connections with NPP’s interfaces, and (4) functionality of the equipment. The CAE proved in this way its capability to provide support to the Spanish NPPs, to strengthen their already strong characteristics in EP&R, to face these new extended damage/beyond design basis scenarios.

Strategy, culture and safety

This article summarizes the research conducted into the emerging concern of the cultural transformation of nuclear power plants as a result of the economic deregulation of the electricity markets which began in most Western countries in the 90s. An alternative theoretical framework is proposed, the cultural organization model, which enables cultural analysis to be performed from the twofold dimension of competitiveness and safety. The empirical application of this model to analyze the cultural configurations of four Spanish nuclear power plants provides a hitherto inexistent baseline of cultural research, centered on revealing the companies' commitment to identifying problems and their capability for collective learning, two basic processes for understanding the social construction of nuclear safety.

Strengthening Safety Compliance in Nuclear Power Operations: A Role‐Based Approach

Safety compliance is of paramount importance in guaranteeing the safe running of nuclear power plants. However, it depends mostly on procedures that do not always involve the safest outcomes. This article introduces an empirical model based on the organizational role theory to analyze the influence of legitimate sources of expectations (procedures formalization and leadership) on workers' compliance behaviors. The sample was composed of 495 employees from two Spanish nuclear power plants. Structural equation analysis showed that, in spite of some problematic effects of proceduralization (such as role conflict and role ambiguity), procedure formalization along with an empowering leadership style lead to safety compliance by clarifying a worker's role in safety. Implications of these findings for safety research are outlined, as well as their practical implications.

Testing the validity of the International Atomic Energy Agency (IAEA) safety culture model

This paper takes the first steps to empirically validate the widely used model of safety culture of the International Atomic Energy Agency (IAEA), composed of five dimensions, further specified by 37 attributes. To do so, three independent and complementary studies are presented. First, 290 students serve to collect evidence about the face validity of the model. Second, 48 experts in organizational behavior judge its content validity. And third, 468 workers in a Spanish nuclear power plant help to reveal how closely the theoretical five-dimensional model can be replicated. Our findings suggest that several attributes of the model may not be related to their corresponding dimensions. According to our results, a one-dimensional structure fits the data better than the five dimensions proposed by the IAEA. Moreover, the IAEA model, as it stands, seems to have rather moderate content validity and low face validity. Practical implications for researchers and practitioners are included.

Exposure to ionising radiations arising from the operation of nuclear installations and cancer mortality

World-wide controversy continues to surround the question of whether exposure to ionising radiations arising from nuclear power plants and radioactive fuel cycle facilities could increase the risk of cancer. The objective was to analyse cancer mortality in towns close to Spanish nuclear power plants and radioactive fuel cycle facilities by reference to their history of exposure to artificial radiation generated by such emissions. An ecological cancer mortality study was conducted to know the effect of artificial radiation, estimated taken into account the magnitude of emissions, in towns ≤30 km of any installation. A model of atmospheric and aquatic dispersion of radionuclides was used. As reference, towns within a 50–100 km radius were matched with exposed by socio-demographic characteristics. For analysis purposes, log-linear Poisson models were fitted. The cumulative effective dose was the measure of exposure. Mortality rates ratios were calculated for each tumour site. Natural radiation and socio-demographic matching variables were included in the models, with ‘installation’ as a random effects term. The estimated cumulative artificial radiation dose was below 350 μSv for all sites. For nuclear power plants overall, analysis showed no positive association with increases in the cumulative dose. In the joint analysis of radioactive fuel cycle facilities, however, mortality was observed to rise with increases in the estimated radiation dose in the case of lung, bone and colorectal cancer, and in breast cancer among women. These results would not appear to be due to exposure arising from the operation of the installations, since were not reproduced around installations of the same type.

Validation of the group nuclear safety climate questionnaire

IntroductionGroup safety climate is a leading indicator of safety performance in high reliability organizations. Zohar and Luria (2005) developed a Group Safety Climate scale (ZGSC) and found it to have a single factor. MethodThe ZGSC scale was used as a basis in this study with the researchers rewording almost half of the items on this scale, changing the referents from the leader to the group, and trying to validate a two-factor scale. The sample was composed of 566 employees in 50 groups from a Spanish nuclear power plant. Item analysis, reliability, correlations, aggregation indexes and CFA were performed. ResultsResults revealed that the construct was shared by each unit, and our reworded Group Safety Climate (GSC) scale showed a one-factor structure and correlated to organizational safety climate, formalized procedures, safety behavior, and time pressure. “Impact on IndustryThis validation of the one-factor structure of the Zohar and Luria (2005) scale could strengthen and spread this scale and measure group safety climate more effectively.

The cultural organisation model: analysing the cultural construction of nuclear safety

The economic deregulation of the electricity markets which began in most Western countries in the 1990s has given rise to a previously non-existent field of research. Nuclear power plants have been particularly affected, and as a result of these financial pressures are undergoing significant cultural changes that are having a negative impact on their safety. This research aims to examine this emerging concern from an alternative theoretical framework, the cultural organisation model, which includes the four dimensions that are needed to make a cultural analysis of any organisation: content, consensus, coherence, and consistency over time. The use of this model to analyse the cultural changes taking place in Spanish nuclear power plants provides a hitherto inexistent baseline of cultural research, which facilitates an understanding of the social construction of nuclear safety.

Bayesian network analysis of safety culture and organizational culture in a nuclear power plant

Many high-hazard industries around the world have explicitly recognized the critical role that human, management and organizational risk factors play in major accidents. The findings of accident investigations and risk assessments demonstrate a growing recognition that the cultural context of work practices may influence safety just as much as technology.The objective of this paper is to establish a relationship between the concepts of safety culture and organizational culture in a Nuclear Power Plant (NPP). This study permits the identification and quantification of the possible mechanisms for improving the safety culture in the NPP acting on organizational culture. It therefore provides a methodology to identify potential strategies for safety improvement.Probabilistic (Bayesian) Networks (BNs) have been used to determine the relationships between the organizational culture and safety culture in a quantitative form. To this aim, we considered data from a survey conducted of every employee at a Spanish NPP. The resulting data-driven models allow us to establish the probabilistic relationship among organizational culture factors, including the 12 OCI (Organizational Culture Inventory) scales, that have an influence on safety culture. The study yielded a ranking of organizational cultures that can be used to improve safety culture in a NPP.