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Impact on the Sustainable Development Goals (SDGs)

Analysis of institutional authors

Fernandez-Cosials K, Queral C, Robledo F, Sánchez-Perea MAuthorQueral, CesarCorresponding Author

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March 4, 2024
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Analysis of a LBLOCA with FLEX actuations in a PWR-W

Publicated to: NUCLEAR ENGINEERING AND DESIGN. 370 110908- - 2020-12-15 370(), DOI: 10.1016/j.nucengdes.2020.110908

Authors:

Fernandez-Cosials, Kevin; Queral, Cesar; Robledo, Fernando; Sanchez-Perea, Miguel
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Affiliations

Nucl Safety Council, Pedro Justo Dorado St, Madrid 28040, Spain - Author
Nuclear Safety Council, Pedro Justo Dorado Street, Madrid, 28040, Spain - Author
Univ Politecn Madrid, Alenza 4 St, Madrid 2803, Spain - Author
Universidad Politécnica de Madrid, Alenza 4 Street, Madrid, 2803, Spain - Author
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Abstract

After the Fukushima-Daiichi accident, different methods, strategies and guidelines were developed to improve the Severe Accident Management Guidelines (SAMG). One of these additions, named the FLEX strategies, relies on portable equipment to obtain power or water to restore key safety functions in the reactor. In the present study, the FLEX strategies are studied under an in-vessel molten core retention scenario; these actions will try to avoid the reactor pressure vessel failure when the core is in a degraded or molten state. In order to analyze this sequence, a large break LOCA is simulated in a three loops PWR-W using the MELCOR 2.2 code. During the simulated sequences different configurations are assessed; the water injection by the ECCS during the recirculation phase is supposed to fail at different times, and the water injection with portable equipment subsequently occurs also at different times after the ECCS failure. Additionally, different water injection rates are also analyzed to compare different portable pumps capabilities. The obtained results agree with previous literature, i.e. the reactor vessel failure could be precluded if the water injection with portable equipment starts before there is a large amount of corium in the lower head. No significant differences are found between different water injection rates (20-60 kg/s) to prevent vessel failure, but it does have an impact on the containment pressure and hydrogen generated. © 2020
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Keywords

AccidentsClean water and sanitationFailure (mechanical)FlexFukushima daiichiIvrLblocaMelcorOutagesPortable equipmentPressure vesselsPressurized water reactorsReactor pressure vesselReactor vesselRecirculationsSafety functionsSevere accidentSevere accident management guidelinesVessel failureWater injection rate

Quality index

Bibliometric impact. Analysis of the contribution and dissemination channel

The work has been published in the journal NUCLEAR ENGINEERING AND DESIGN due to its progression and the good impact it has achieved in recent years, according to the agency Scopus (SJR), it has become a reference in its field. In the year of publication of the work, 2020, it was in position , thus managing to position itself as a Q1 (Primer Cuartil), in the category Safety, Risk, Reliability and Quality. Notably, the journal is positioned above the 90th percentile.

From a relative perspective, and based on the normalized impact indicator calculated from World Citations provided by WoS (ESI, Clarivate), it yields a value for the citation normalization relative to the expected citation rate of: 1.16. This indicates that, compared to works in the same discipline and in the same year of publication, it ranks as a work cited above average. (source consulted: ESI Nov 13, 2025)

Specifically, and according to different indexing agencies, this work has accumulated citations as of 2026-04-26, the following number of citations:

  • WoS: 11
  • Scopus: 12
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Impact and social visibility

From the perspective of influence or social adoption, and based on metrics associated with mentions and interactions provided by agencies specializing in calculating the so-called "Alternative or Social Metrics," we can highlight as of 2026-04-26:

  • The use of this contribution in bookmarks, code forks, additions to favorite lists for recurrent reading, as well as general views, indicates that someone is using the publication as a basis for their current work. This may be a notable indicator of future more formal and academic citations. This claim is supported by the result of the "Capture" indicator, which yields a total of: 3 (PlumX).

It is essential to present evidence supporting full alignment with institutional principles and guidelines on Open Science and the Conservation and Dissemination of Intellectual Heritage. A clear example of this is:

  • Assignment of a Handle/URN as an identifier within the deposit in the Institutional Repository: https://oa.upm.es/94018/

As a result of the publication of the work in the institutional repository, statistical usage data has been obtained that reflects its impact. In terms of dissemination, we can state that, as of

  • Views: 20
  • Downloads: 12
Continuing with the social impact of the work, it is important to emphasize that, due to its content, it can be assigned to the area of interest of ODS 6 - Clean water and sanitation, with a probability of 57% according to the mBERT algorithm developed by Aurora University.
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Leadership analysis of institutional authors

There is a significant leadership presence as some of the institution’s authors appear as the first or last signer, detailed as follows: First Author (FERNÁNDEZ COSIALS, MIKEL KEVIN) .

the author responsible for correspondence tasks has been QUERAL SALAZAR, JOSE CESAR.

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Project objectives

Los objetivos perseguidos en esta aportación son analizar la efectividad de las estrategias FLEX en un escenario de retención del núcleo fundido dentro del vaso del reactor; evaluar la secuencia de un accidente LOCA de gran ruptura en un reactor PWR-W de tres circuitos mediante simulaciones con el código MELCOR 2.2; determinar el impacto del fallo temporal de la inyección de agua del ECCS durante la fase de recirculación y la posterior activación de equipos portátiles; comparar diferentes tasas de inyección de agua (20-60 kg/s) para evaluar la capacidad de las bombas portátiles; y caracterizar las consecuencias sobre la presión del contenedor y la generación de hidrógeno en función de las tasas de inyección.
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Most relevant results

El estudio analiza la eficacia de las estrategias FLEX en la retención del núcleo fundido dentro del vaso del reactor durante un LBLOCA en un PWR-W mediante simulaciones con MELCOR 2.2. Los resultados más relevantes son: (1) la falla del vaso del reactor puede evitarse si la inyección de agua con equipos portátiles comienza antes de la acumulación significativa de corio en el hemisferio inferior; (2) no se observan diferencias significativas en la prevención de la falla del vaso entre tasas de inyección de agua de 20 a 60 kg/s; (3) la tasa de inyección sí afecta la presión de contención y la generación de hidrógeno; (4) se evaluaron diferentes tiempos de fallo del ECCS y de inicio de la inyección portátil, demostrando la importancia del momento de actuación para la mitigación del accidente.
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