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28 results on '"Purba, Julwan Hendry"'

1. Event Sequence Based Fault Tree Analysis to Evaluate Minimal Combination of Event Sequences Leading to the Reactor Core Damage.

Author

SONY TJAHYANI, Damianus Toersiwi, PURBA, Julwan Hendry, EKARIANSYAH, Andi Sofrany, WIDODO, Surip, SUSYADI, Susyadi, and TYAS, Ratih Luhuring

Subjects
*FAULT trees (Reliability engineering), *NUCLEAR reactor cores, *SYSTEM failures, *SYSTEM safety, *STORAGE tanks
Abstract

Probabilistic safety assessment has been widely used to evaluate nuclear power plant safety systems. It couples fault tree (FT) analysis and event tree (ET) analysis. The FT analysis is to develop failure scenarios, to quantify the failure probability, and to identify critical components. The ET analysis is to develop event sequences (ESs) leading to reactor core damage and quantify core damage frequency. Currently, there is no approach in probabilistic safety assessment that can be used to identify minimal combinations of safety system failures leading to reactor core damage. This study proposes an event sequence based fault tree analysis, which integrates the FT model with the ET model. The ET model is to identify the ESs leading to the reactor core damage. Meanwhile, the FT model is to identify minimal combinations of those ESs found in the ET model. The motivation of this study is how to identify critical safety systems in nuclear power plants to mitigate disturbances caused by a group of postulated initiating events to avoid core damage. To confirm the feasibility and the applicability of the proposed approach, the performance of the AP1000 passive core cooling system is evaluated. It is found that if an in-containment refueling water storage tank, an automatic depressurization system - full, an accumulator, a core make-up tank, and a passive residual heat removal work properly, the reactor core will remain intact. These results confirmed that the proposed approach could be applicable to identify minimal combinations of safety systems to keep the reactor core intact. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Nuclear power plant probabilistic safety assessment by fuzzy approach: current states, future research directions and challenges

Author

Purba, Julwan Hendry, Hendayun, Mokhamad, Tjahyani, Damianus Toersiwi Sony, I, Susila, Putu, Wahanani, Nursinta Adi, and Waskita, Arya Adhyaksa

Abstract

Probabilistic safety assessment (PSA) has been widely implemented in nuclear power plant (NPP) safety analysis. In PSA, all events are always assumed to have their own historical failure data. This becomes the technical challenge in PSA. To deal with this limitation, fuzzy PSA has been proposed. Fuzzy concept is introduced to model system reliability when quantitative historical failure data is limited or unavailable. This study reviews the implementation of fuzzy fault tree analysis and fuzzy event tree analysis in NPP safety assessment. To stimulate further research directions, the limitations of existing fuzzy PSA and challenges for future studies are also discussed. The study confirms that fuzzy PSA offers some features to overcome the constraints of conventional PSA. Nevertheless, fuzzy PSA still has some challenges to be dealt with. To improve the capabilities of fuzzy PSA in the future, those limitations and challenges still need to be practically and scientifically overcome.

Published
2023
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15. The Implementation of Fault Tree Analysis Approaches in Nuclear Power Plant Probabilistic Safety Assessment.

Author

Purba, Julwan Hendry, Sony Tjahyani, Damianus Toersiwi, and Deswandri

Abstract

Probabilistic safety assessment (PSA) has been extensively implemented to assess the performance of nuclear power plant (NPP) safety systems. One well-known modeling approach in NPP PSA is a fault tree analysis (FTA). A fault tree is a graphical representation of possible failure scenarios of the system being evaluated. To estimate the top event failure probability, a quantitative analysis needs to be performed based on those scenarios. Prior to performing quantitative analysis, basic events’ failure probabilities of the system fault tree need to be provided well in advance. Conventional FTA assumes that basic events always have precise probability distributions characterizing their lifetime to failure. However, in practical applications, this is not the case. For example, a new system will not have sufficient operating experiences to probabilistically estimate reliabilities of their components. To deal with this limitation, a number of approaches has been developed and proposed. Each approach offers advantageous but also has disadvantageous. Since the results of FTA will be used to verify NPP designs, it is necessary to select the most suitable approach. It is, therefore, essential to clearly understand the strengths and weaknesses of each approach. The purpose of this study is to review the implementation of various FTA approaches in NPP PSA. The strengths and weaknesses of each approach are also discussed. To achieve research objectives, this study classified those FTA approaches into conventional FTA and fuzzy FTA. Fuzzy FTA is further grouped into fuzzy hybrid FTA and fuzzy based FTA. This study concludes that safety analysts need to, firstly, confirm the type of reliability data at hands. Secondly, if epistemic uncertainty is essential and need to be considered in the study being performed, fuzzy based FTA should be applied. Otherwise, safety analysts should apply conventional FTA or fuzzy hybrid FTA depending on how the basic events’ failure probabilities are generated. [ABSTRACT FROM AUTHOR]

Published
2019
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21. Experts' Selection in the Application of Fuzzy Fault Tree Analysis to Evaluate an RSG - GAS Primary Cooling System.

Author

Kumaraningrum, Anggraini Ratih, Hermansyah, Heri, and Purba, Julwan Hendry

Subjects
FAULT trees (Reliability engineering), PROBABILITY theory, NUCLEAR reactors, RELIABILITY in engineering, COOLING systems
Abstract

Reliability data are very important for probabilistic safety assessment by fault tree analysis. Due to the limitations of historical failure data of the system being evaluated, generic data have been occupied. However, generic data comes with uncertainties and, hence, cannot represent its real performance. To overcome this limitation, fuzzy probability has been integrated into conventional fault tree analysis to evaluate the performance of nuclear reactors' safety systems. In fuzzy fault tree analysis, the qualitative judgments of experts are collected to assess the failure possibility of basic events. Furthermore, the membership functions of fuzzy numbers are used to convert those qualitative judgments into quantitative data. The assessment made by experts is a subjective judgment. Each expert has varying levels of expertise, so assessment of the same basic event will provide different judgments. The experts who are involved in the assessment process should be selected properly, because expert judgment is very influential on the final outcome of analysis. This study proposes a four stage expert selection process. Through the implementation of the proposed approach, five groups of experts has been selected. The five groups consisted of (1) head of division (reactor maintenance division, reactor operation division, and occupational and operation safety division); (2) head of subdivision (mechanical system subdivision, electrical system subdivision, instrumentation and control subdivision, operation reactor subdivision, and operation safety subdivision); (3) supervisor of reactor and supervisor of maintenance; (4) operator of reactor and maintenance technician; (5) radiation protection officer and staff of operation safety subdivision. [ABSTRACT FROM AUTHOR]

Published
2018
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27. Safety Analysis Technique for System with Limited Data: Case Study of the Multipurpose Research Reactor in Indonesia.

Author

Hermansyah, Heri, Kumaraningrum, Anggraini Ratih, Purba, Julwan Hendry, Edison, and Yohda, Masafumi

Subjects
FAULT trees (Reliability engineering), CASE studies, MULTIPURPOSE buildings, RESEARCH reactors, CHEMICAL engineering, SYSTEM analysis, NUCLEAR industry, NUCLEAR energy
Abstract

Fault tree analysis (FTA) is frequently applied to deductively evaluate the safety systems of complex engineering systems such as chemical industries or nuclear facilities. To perform this analysis, generic data are commonly used due to the limitation of historical failure data of the system being evaluated. However, generic data have a degree of uncertainty and hence cannot represent the system's actual performance. In addition, generic data are not applicable to older components due to the aging process, which obviously degrades the reliability of those components. To deal with this limitation, another safety analysis method, called fuzzy fault tree analysis (FFTA), has been proposed. The purpose of this study is to apply FFTA to evaluate the performance of the primary cooling systems of G.A. Siwabessy Multipurpose Reactor (RSG-GAS). RSG-GAS is a research reactor, which belongs to the National Nuclear Energy Agency of Indonesia (BATAN). Expert justifications were used to evaluate the failure occurrences of basic events in the primary cooling system of the RSG–GAS through questionnaires. The assessment by experts is in the form of qualitative data, which are then converted into quantitative data by applying FFTA. Then, the top event probability generated from FFTA was applied to calculate the event probability using event tree analysis (ETA). It was obtained that the highest event probability was 4.304 × 10−8/year. Since it complies with The International Atomic Energy Agency (IAEA) specified core damage frequency (CDF) limit, i.e., not greater than 10−5/year of reactor operation, the reactor is safe to operate. [ABSTRACT FROM AUTHOR]

Published
2020
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28. Journal of Physics. Conference Series

Author

Rahayu, Yuni Sri, Ekawati, Rooselyna, Nandiyanto, Asep Bayu Dani, Lukito, Agung, Wibawa, Setya Chendra, Purnomo, Yoppy Wahyu, Roza, Liszulfa, Aziz, Tian Abdul, Perbowo, Krisna Satria, Ulfah, Syafika, Escobar, Carlos Ruiz, Noordmans, Jacob, Lehnert, Ralf, Potting, Robertus, Meshkov, Sydney, Faryad, Muhammad, Sunaryo, Geni Rina, Purba, Julwan Hendry, Olivieri, Giacomo, Rajo-Iglesias, Eva, Gargano, Angela, Coraggio, Luigi, Itaco, Nunzio, Chruściel, Piotr T., Grant, James, Kunzinger, Michael, Minguzzi, Ettore, Bylander, Jonas, Löfwander, Tomas, Misiorny, Maciej, Motlan, Motlan, Restuati, Martina, Rajagukguk, Juniastel, Gröbner, Julian, Costa-Felix, Rodrigo P. B., Jiaotong, Yong Yue Xi'an, Tahir, Dahlang, Benova, E., Atanasova, M., Khaerudini, Deni S., Febriani, Febty, Oemry, Ferensa, Sugihartono, Iwan, Setiawan, Riza, Syuhada, Syuhada, Widayatno, Wahyu Bambang, Sugiarti, Eni, Ma, Yufei, Isnaeni, Isnaeni, Izzuddin, Hubby, Susila, I Putu, Sudiro, Toto, Herbani, Yuliati, Tai, Yan, Sanden, M.C.M. van de, Suris, R. A., Vorobjev, L. E., Firsov, D. A., Shalygin, V. A., Raikher, Yuriy, Balasoiu, Maria, Rogachev, Andrey, Bunoiu, Madalin, Jatmiko, Budi, Madlazim, Madlazim, Munasir, Munasir, Supardi, Imam, Deta, Utama Alan, Govindarajan, A., Siva, E. P., Suja, K., Jimenez, Javier, Flórez, Fernando Durán, Niño, Ely Dannier V., Atta Makki, Sameer, Abdul Latef, Firas Abdul Hameed, Tawfig, Luma Naji Mohammed, Al-Radi Al-Bakri, Nahla Abdul, Shakir, Raied Mustafa, Junjunan, Soleh Fajar, Prayogi, Afrido, Windya, Sridana, Dafik, Dafik, Surzhikov, Sergey T., Vaz da Costa, Bismarck, Martins, Paulo Henrique, Mol, Lucas Alvares, Pereira, Luiz Felipe C., Plascak, João Antonio, Mandaglio, Giuseppe, Trifirò, Antonio, Trimarchi, Marina, Indriyanti, Nurma Yunita, Ramli, Murni, Karyanto, Puguh, Pramesti, Getut, Warsito, Budi, Putro, Sapto Purnomo, Khumaeni, Ali, Kettani, Houssain, Sivakumar, R., Song, Iickho, Hernandez, Hector, Chacón, Guillermo, Sabido, Miguel, Raj, Ewa, Znajdek, Katarzyna, Hoang, Trinh Xuan, Tuan, Hoang Anh, Tuoc, Vu Ngoc, Taniguchi, Shigeru, Arima, Takashi, Ohzeki, Masayuki, Teppei, Ikeya, Kuwatani, Tatsu, Nakanishi-Ohno, Yoshinori, Miyama, Masamichi J., Obuchi, Tomoyuki, Averkiev, Nikita S., Poniaev, Sergey A., Sokolovskii, Grigorii S., Han, Jong, Kim, Ki-Seok, Correa, Rafael, Roa, Luis, Soto, Leopoldo, Navarro, Ignacio Herrera, Kaczmarczyk, Stefan, Zhao, Yichuan, Maeda, Atsutaka, Yoshida, Yoshiyuki, Hidaka, Mutsuo, Kuwabara, Toshihiko, Hama, Takayuki, Kuroda, Mitsutoshi, Takahashi, Susumu, Yamanaka, Akinori, Koscielniak, Shane, Khalimullovich, Salakhov Myakzyum, Vladimirovich, Samartsev Vitalii, Khamitovich, Gainutdinov Renat, Tseng, Juinling, Kotenko, Igor, Asnafi, Nader, Sokołowska, Dagmara, Acosta, Luis, Amador-Valenzuela, Paulina, Velazquez, Victor, Spindloe, Christopher, Risdiana, Risdiana, Furukawa, Yukio, Sulaiman, Shukri, Rusydi, Andrivo, Alatas, Husin, Oughaddou, Hamid, Kara, Abdelkader, Bendounan, Azzedine, Lasri, Karima, Mayne, Andrew, Kaddouri, Abedlilah, Rochdi, Nabil, El Boujlaidi, Abdelaziz, Lemaire, Jean-Louis, Amine, Khalil, Tétard, Laurène, Saadoune, Ismael, Jafri, Zubir Mat, Mahmud, Shahrom, Omar, Ahmad Fairuz, Arshad, Suhana, Gorlatch, Sergei, Mladenov, Georgi, Mufti, Nandang, Ivanov, V. A., Grishina, I. A., Voronova, E. V., Subiantoro, Agung Wijaya, Suyanto, Slamet, Butar Butar, Ferry, Borman, Vladimir D., Zank, G. P., Muskulus, Michael, Bottasso, Carlo L., Tande, John Olav Giæver, Kvamsdal, Trond, Fiangga, Shofan, Jakfar, M., Tomasini, Enrico Primo, Li, Wei, Sumiyoshi, Abe, Wang, Alexandre, Morales, Jimmy Alexander, Reyes, Ángel Manuel Meléndez, Gutiérrez, Jorge Andrés Calderón, Palma, Ricardo A. Torres, Ramdani, Rahmat, Kurniawati, Frida, Chen, Chuei Yee, Lee, Lai Soon, Kilicman, Adem, Ismail, Fudziah, Midi, Habshah, Gafurjan, Ibragimov, Husain, Sharifah Kartini Said, Ibrahim, Siti Nur Iqmal, Romanenko, Vladislav, Bogdanova, Ekaterina, Smirnov, Anton, Balakin, Boris, Simon, Martin, Kolbinger, Bernadette, Widmann, Eberhard, Karshenboim, Savely, Sivasankaran, S., Eswaramoorthi, S., Sudira, Putu, Djatmiko, Istanto Wahyu, Asnawi, Rustam, Suprapto, Nadi, Herawan, T., Vlachos, Dimitrios S., George, Fr. Augustine, Pandian, A. Sevuga, Vinothina, V., Donald, A. Cecil, Laosiritaworn, Y., Pattanaporkratana, A., and Thountom, S.

Published
2018

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