Consejo de Seguridad Nuclear CSN

Madrid, Spain

Consejo de Seguridad Nuclear CSN

Madrid, Spain
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Sanchez-Doblado F.,Hospital Universitario Virgen Macarena | Sanchez-Doblado F.,University of Seville | Domingo C.,Autonomous University of Barcelona | Gomez F.,University of Santiago de Compostela | And 28 more authors.
Physics in Medicine and Biology | Year: 2012

Neutron peripheral contamination in patients undergoing high-energy photon radiotherapy is considered as a risk factor for secondary cancer induction. Organ-specific neutron-equivalent dose estimation is therefore essential for a reasonable assessment of these associated risks. This work aimed to develop a method to estimate neutron-equivalent doses in multiple organs of radiotherapy patients. The method involved the convolution, at 16 reference points in an anthropomorphic phantom, of the normalized Monte Carlo neutron fluence energy spectra with the kerma and energy-dependent radiation weighting factor. This was then scaled with the total neutron fluence measured with passive detectors, at the same reference points, in order to obtain the equivalent doses in organs. The latter were correlated with the readings of a neutron digital detector located inside the treatment room during phantom irradiation. This digital detector, designed and developed by our group, integrates the thermal neutron fluence. The correlation model, applied to the digital detector readings during patient irradiation, enables the online estimation of neutron-equivalent doses in organs. The model takes into account the specific irradiation site, the field parameters (energy, field size, angle incidence, etc) and the installation (linac and bunker geometry). This method, which is suitable for routine clinical use, will help to systematically generate the dosimetric data essential for the improvement of current risk-estimation models. © 2012 Institute of Physics and Engineering in Medicine.


Berg H.-P.,Bundesamt Fur Kerntechnische Entsorgungssicherheit BfE | Albaizar E.A.,Consejo de Seguridad Nuclear CSN | Fritze N.,Bundesamt Fur Kerntechnische Entsorgungssicherheit BfE | Rowekamp M.,GRS Society for plants and Reactor Safety
PSAM 2016 - 13th International Conference on Probabilistic Safety Assessment and Management | Year: 2017

The international database OECD FIRE on fire incidents in nuclear power plants (NPP) has been recently investigated regarding the operating experience in the participating member countries with respect to event combinations of fires and other events. Causally related events, either fires and consequential events or initiating events and consequential fires, have been observed as well as combinations of fires and other events having occurred independently of each other at the same time. The fact that the amount of such event combinations is more than 10 % of the entire 448 event records in the database, of which the majority are fire events without safety significance, is notable. In total 49 event combinations have been identified in the FIRE Database up to the end of 2015, the vast majority of them representing combinations of initial internal hazards, such as high energy arcing faults (HEAF), explosions or missiles, and consequential fires. Approximately 1 % of the entire events collected in the FIRE Database are fires resulting from external hazards. Approximately one quarter (12 events) of the above mentioned 49 event combinations recorded are fires and consequential events: seven of these initial fires resulted e.g. in an internal flooding as a consequential event. The number of records of fire event combinations with more than one consequential event, of which at least one represents a fire, is seven representing 15 % of all event combinations identified in the database. This number is nonnegligible and also indicates potential domino effects which may impair nuclear safety. One general conclusion from this study is that event combinations fires and other events (hazards) and their potential consequences to plant safety need to be more systematically analyzed and considered in probabilistic risk assessment (PRA). They have also to be adequately addressed in the plant design. This underpins similar lessons learned from post-Fukushima investigations. Combinations of a majority of internal and external hazards not exceeding the design basis have already been accounted for in the plant fire safety concepts and are also addressed in the regulations of several countries. However, some consequences of fires, in particular flooding from extinguishing activities, need more systematic consideration. Moreover, the consequences of event combinations involving HEAF and fire need further in-depth investigation. This may result in plant modifications in the future including improved procedures.


Garcia-Talavera M.,Consejo de Seguridad Nuclear CSN | Garcia-Perez A.,Spanish University for Distance Education (UNED) | Rey C.,Consejo de Seguridad Nuclear CSN | Ramos L.,Consejo de Seguridad Nuclear CSN
Journal of Radiological Protection | Year: 2013

Identifying radon-prone areas is key to policies on the control of this environmental carcinogen. In the current paper, we present the methodology followed to delineate radon-prone areas in Spain. It combines information from indoor radon measurements with γ-radiation and geological maps. The advantage of the proposed approach is that it lessens the requirement for a high density of measurements by making use of commonly available information. It can be applied for an initial definition of radon-prone areas in countries committed to introducing a national radon policy or to improving existing radon maps in low population regions. © 2013 IOP Publishing Ltd.


Dusic M.,International Atomic Energy Agency | Dutton M.,Consultant | Glaeser H.,GRS Society for plants and Reactor Safety | Herb J.,GRS Society for plants and Reactor Safety | And 3 more authors.
Nuclear Technology | Year: 2014

In 2009 the International Atomic Energy Agency (IAEA) published "Deterministic Safety Analysis for Nuclear Power Plants Specific Safety Guide," Specific Safety Guide No. SSG-2 (hereinafter referred to as SSG-2). SSG-2 addresses four options for the application of deterministic safety analyses. Option 1, which has been used since the early days of civil nuclear power and is still used today, uses conservative codes/models and conservative initial and boundary (I&B) conditions. Option 2, which is frequently used worldwide, uses realistic codes/models but with conservative I&B conditions. Option 3 uses realistic codes/models and realistic I&B conditions and therefore needs also to consider the associated uncertainties. Today, option 3 is known as the Best Estimate Plus Uncertainty option. Option 4 is not developed in SSG-2 and only indicates that option 4 is an attempt to combine insights from probabilistic safety analyses with a deterministic approach, which results in a risk-informed safety analysis. In options 1, 2, and 3, the availability of safety systems is based on conservative assumptions, whereas in option 4, the availability of safety systems is derived by probabilistic means. This paper explains in more detail the approach proposed for option 4 and provides illustrative examples for its application, recognizing the fact that option 4 is still a research option and will remain so for some time.


Ibanez-Llano C.,Comillas Pontifical University | Rauzy A.,Dassault Systemes | Melendez E.,Consejo de Seguridad Nuclear CSN | Nieto F.,Comillas Pontifical University
Reliability Engineering and System Safety | Year: 2010

Binary decision diagrams are a well-known alternative to the minimal cutsets approach to assess the reliability Boolean models. They have been applied successfully to improve the fault trees models assessment. However, its application to solve large models, and in particular the event trees coming from the PSA studies of the nuclear industry, remains to date out of reach of an exact evaluation. For many real PSA models it may be not possible to compute the BDD within reasonable amount of time and memory without considering the truncation or simplification of the model. This paper presents a new approach to estimate the exact probabilistic quantification results (probability/frequency) based on combining the calculation of the MCS and the truncation limits, with the BDD approach, in order to have a better control on the reduction of the model and to properly account for the success branches. The added value of this methodology is that it is possible to ensure a real confidence interval of the exact value and therefore an explicit knowledge of the error bound. Moreover, it can be used to measure the acceptability of the results obtained with traditional techniques. The new method was applied to a real life PSA study and the results obtained confirm the applicability of the methodology and open a new viewpoint for further developments. © 2010 Elsevier Ltd. All rights reserved.


Ibanez-Llano C.,Comillas Pontifical University | Rauzy A.,Dassault Systemes | Melendez E.,Consejo de Seguridad Nuclear CSN | Nieto F.,Comillas Pontifical University
Reliability Engineering and System Safety | Year: 2010

Over the last two decades binary decision diagrams have been applied successfully to improve Boolean reliability models. Conversely to the classical approach based on the computation of the MCS, the BDD approach involves no approximation in the quantification of the model and is able to handle correctly negative logic. However, when models are sufficiently large and complex, as for example the ones coming from the PSA studies of the nuclear industry, it begins to be unfeasible to compute the BDD within a reasonable amount of time and computer memory. Therefore, simplification or reduction of the full model has to be considered in some way to adapt the application of the BDD technology to the assessment of such models in practice. This paper proposes a reduction process based on using information provided by the set of the most relevant minimal cutsets of the model in order to perform the reduction directly on it. This allows controlling the degree of reduction and therefore the impact of such simplification on the final quantification results. This reduction is integrated in an incremental procedure that is compatible with the dynamic generation of the event trees and therefore adaptable to the recent dynamic developments and extensions of the PSA studies. The proposed method has been applied to a real case study, and the results obtained confirm that the reduction enables the BDD computation while maintaining accuracy. © 2010 Elsevier Ltd. All rights reserved.


Garcia-Talavera M.,Consejo de Seguridad Nuclear CSN | Matarranz J.L.M.,Consejo de Seguridad Nuclear CSN | Salas R.,Consejo de Seguridad Nuclear CSN | Ramos L.,Consejo de Seguridad Nuclear CSN
Journal of Environmental Radioactivity | Year: 2011

Radioactive and chemical risks coexist in NORM industries although they are usually addressed separately by regulations. The European Union (EU) has developed extensive legislation concerning both matters, which has been diversely reflected in national policies. We consider the case of the Spanish phosphate industry and analyse to which extent regulatory mandates have reduced the historical and ongoing radiological impact on the environment of phosphate facilities. Although no specific radiological constraints on effluent monitoring and release or on waste disposal have yet been imposed on NORM industries in Spain, other environmental regulations have achieved a substantial reduction on the phosphate industry impact. Nevertheless, a more efficient control could be established by eliminating the current conceptual and practical separation of chemical and radioactive risks in NORM industries. We highlight research needs to accomplish so and propose shorter-term measures that require active cooperation among the regulatory bodies involved. © 2010.


Jimenez M.A.,Consejo de Seguridad Nuclear CSN | Martin-Valdepenas J.M.,Consejo de Seguridad Nuclear CSN | Garcia-Talavera M.,Consejo de Seguridad Nuclear CSN | Martin-Matarranz J.L.,Consejo de Seguridad Nuclear CSN | And 3 more authors.
Journal of Environmental Radioactivity | Year: 2011

In the frame of an epidemiological study carried out in the influence areas around the Spanish nuclear facilities (ISCIII-CSN, 2009. Epidemiological Study of The Possible Effect of Ionizing Radiations Deriving from The Operation of Spanish Nuclear Fuel Cycle Facilities on The Health of The Population Living in Their Vicinity. Final report December 2009. Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III, Consejo de Seguridad Nuclear. Madrid. Available from: http://www.csn.es/images/stories/actualidad_datos/especiales/epidemiologico/epidemiological_study.pdf), annual effective doses to public have been assessed by the Spanish Nuclear Safety Council (CSN) for over 45 years using a retrospective realistic-dose methodology. These values are compared with data from natural radiation exposure. For the affected population, natural radiation effective doses are in average 2300 times higher than effective doses due to the operation of nuclear installations (nuclear power stations and fuel cycle facilities). When considering the impact on the whole Spanish population, effective doses attributable to nuclear facilities represent in average 3.5×10 -5mSv/y, in contrast to 1.6mSv/y from natural radiation or 1.3mSv/y from medical exposures. © 2011 Elsevier Ltd.


PubMed | Consejo de Seguridad Nuclear CSN
Type: Journal Article | Journal: Journal of environmental radioactivity | Year: 2010

Radioactive and chemical risks coexist in NORM industries although they are usually addressed separately by regulations. The European Union (EU) has developed extensive legislation concerning both matters, which has been diversely reflected in national policies. We consider the case of the Spanish phosphate industry and analyse to which extent regulatory mandates have reduced the historical and ongoing radiological impact on the environment of phosphate facilities. Although no specific radiological constraints on effluent monitoring and release or on waste disposal have yet been imposed on NORM industries in Spain, other environmental regulations have achieved a substantial reduction on the phosphate industry impact. Nevertheless, a more efficient control could be established by eliminating the current conceptual and practical separation of chemical and radioactive risks in NORM industries. We highlight research needs to accomplish so and propose shorter-term measures that require active cooperation among the regulatory bodies involved.


PubMed | Consejo de Seguridad Nuclear CSN
Type: Journal Article | Journal: Journal of environmental radioactivity | Year: 2011

In the frame of an epidemiological study carried out in the influence areas around the Spanish nuclear facilities (ISCIII-CSN, 2009. Epidemiological Study of The Possible Effect of Ionizing Radiations Deriving from The Operation of Spanish Nuclear Fuel Cycle Facilities on The Health of The Population Living in Their Vicinity. Final report December 2009. Ministerio de Ciencia e Innovacin, Instituto de Salud Carlos III, Consejo de Seguridad Nuclear. Madrid. Available from: http://www.csn.es/images/stories/actualidad_datos/especiales/epidemiologico/epidemiological_study.pdf), annual effective doses to public have been assessed by the Spanish Nuclear Safety Council (CSN) for over 45 years using a retrospective realistic-dose methodology. These values are compared with data from natural radiation exposure. For the affected population, natural radiation effective doses are in average 2300 times higher than effective doses due to the operation of nuclear installations (nuclear power stations and fuel cycle facilities). When considering the impact on the whole Spanish population, effective doses attributable to nuclear facilities represent in average 3.510(-5)mSv/y, in contrast to 1.6mSv/y from natural radiation or 1.3mSv/y from medical exposures.

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