PASCAR: Long burning small modular reactor based on natural circulation

2011 ◽  
Vol 241 (5) ◽  
pp. 1486-1499 ◽  
Author(s):  
Sungyeol Choi ◽  
Jae-Hyun Cho ◽  
Moo-Hoon Bae ◽  
Jun Lim ◽  
Dina Puspitarini ◽  
...  
Keyword(s):  
Natural Circulation ◽  
Small Modular Reactor

Analysis of the natural circulation flow map uncertainties in an integral small modular reactor

2021 ◽  
Vol 378 ◽  
pp. 111156
Author(s):  
Seyed Ali Hosseini ◽  
Reza Akbari ◽  
Amir Saeed Shirani ◽  
Francesco D'Auria
Keyword(s):  
Natural Circulation ◽  
Circulation Flow ◽  
Small Modular Reactor ◽  
Flow Map

Power Maximization of Fully Passive Lead-Bismuth Eutectic Cooled Small Modular Reactor

2014 ◽  
Author(s):  
Jaehyun Cho ◽  
Yong-Hoon Shin ◽  
Il Soon Hwang
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Natural Circulation ◽  
Reactor Core ◽  
Design Stage ◽  
Pressurized Water ◽  
Small Modular Reactor ◽  
Power Maximization ◽  
Lead Bismuth Eutectic ◽  
Water Reactors

Although the current Pressurized Water Reactors (PWRs) have significantly contributed to the global energy supply, PWRs have not been considered as a trustworthy energy solution owing to its several problems; spent nuclear fuels (SNFs), nuclear safety, and nuclear economy. In order to overcome these problems, lead-bismuth eutectic (LBE) fully passive cooling Small Modular Reactor (SMR) system is suggested. It is possible to not only provide the solution of the problem of SNFs through the transmutation feature of LBE coolant, but also increase the safety and economy through the concepts of the natural circulation cooling SMRs. It is necessary to maximize the advantages (safety and economy) of this type of Nuclear Power Plants for several applications in future. Accordingly, objective of the study is to maximize the reactor core power while the limitations of shipping size, materials endurance, long-burning criticality as well as safety under Beyond Design Basis Events must be satisfied. Design limitations of natural circulating LBE-cooling SMRs are researched and power maximization method is developed based on obtained design limitations. It is expected that the results are contributed to reactor design stage with providing several insights to designers as well as the methods for design optimization of other type of SMRs.

Sensitivity Analysis of the SBLOCA Induced Severe Accident for a Natural Circulation Small Modular Reactors

2018 ◽  
Author(s):  
Longze Li ◽  
Jue Wang ◽  
Yapei Zhang ◽  
G. H. Su
Keyword(s):  
Sensitivity Analysis ◽  
Heat Sink ◽  
Natural Circulation ◽  
Management Strategies ◽  
Severe Accident ◽  
Severe Accidents ◽  
Small Modular Reactor ◽  
Fraction Increase ◽  
Crack Position

The natural circulation small modular reactor (NCSMR) is a 330 MW reactor which has no reactor coolant pumps (RCP) and no active safety injection systems at all. The reactor is mainly comprised of the reactor pressure vessel (RPV) with integral pressurize r and steam generator. RPV is enclosed by a vacuumed pressure containment vessel (PCV) and the PCV is submerged in the underground containment pool. A MELCOR model and corresponding input deck are developed for the RPV, PCV, and containment pool. The containment pool takes the role of ultimate heat sink (UHS) in accident situations. The containment pool may crack and leak in some critical accidents as the earthquake, leading to the severe accident of the reactor. A TMI-2 like SBLOCA in the RPV (stuck open RVVs) along with the containment pool crack (loss of ultimate heat sink) is simulated in the work. So me key parameters as the RRVs stuck open fraction, the PCV-SRVs open or not, the containment pool crack position would have large influence on the severe accident sequence. The sensitivity of these parameters to the accident sequence is analyzed in the work. According to the simulation results, the RPV pressure decreased with the RRVs stuck open. The depressurization of RPV accelerated with the RPV-SRV open fraction increase. The PCV pressure increased after that. Two cases as the PCV-SRV open after PCV pressure increase to 5 MPa, and PCV break while the RV d id not open, are analysis. The coolant discharge mass flo wrate in RPV and PCV were different in two cases, leading to the different degradation situation of the core. Since the containment pool is so important for the accident mitigation, sensitivity analysis is done for the containment pool crack position in the pool. The work will be meaningful in gaining an insight into the detailed process involved. One of the final goals of this work would be to identify appropriate accident management strategies and countermeasures for the potential extreme natural hazard induced severe accidents during the design process of NCSMR.

Advanced passive design of small modular reactor cooled by heavy liquid metal natural circulation

2015 ◽  
Vol 83 ◽  
pp. 433-442 ◽  
Author(s):  
Yong-Hoon Shin ◽  
Sungyeol Choi ◽  
Jaehyun Cho ◽  
Ji Hyun Kim ◽  
Il Soon Hwang
Keyword(s):  
Liquid Metal ◽  
Natural Circulation ◽  
Heavy Liquid ◽  
Small Modular Reactor ◽  
Passive Design

scholarly journals Experimental investigation of natural circulation instability in a BWR-type small modular reactor

2015 ◽  
Vol 85 ◽  
pp. 96-107 ◽  
Author(s):  
Shanbin Shi ◽  
Joshua P. Schlegel ◽  
Caleb S. Brooks ◽  
Yu-Chen Lin ◽  
Jaehyuk Eoh ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Natural Circulation ◽  
Small Modular Reactor

Modeling Passive Safety in the Westinghouse Small Modular Reactor: Assessment of Wall Condensation and CMT Natural Circulation

2013 ◽  
Author(s):  
Jun Liao ◽  
Vefa N. Kucukboyaci
Keyword(s):  
Natural Circulation ◽  
Passive Safety ◽  
Reactor Safety ◽  
Heat Transfer Mechanism ◽  
The Core ◽  
Design Basis ◽  
Loss Of Coolant Accident ◽  
Small Modular Reactor ◽  
Loss Of Coolant ◽  
Safety Design

Passive safety design that utilizes gravity, natural circulation, heat sink and stored potential energy for reactor safety functions is being increasingly adopted in advanced reactors, especially in the small modular reactor (SMR) designs. The passive safety design of the Westinghouse SMR is described in details and compared with the AP1000® passive safety design. The natural circulation loops and heat transfer mechanism in a postulated Westinghouse SMR loss of coolant accident (LOCA) are discussed. The key thermal hydraulic phenomena pertinent to the passive safety design of the Westinghouse SMR have been identified in the small break LOCA Phenomena Identification and Rank Table (PIRT). Among the identified phenomena, condensation on the containment wall and natural circulation in core makeup tank (CMT) loop are highly ranked. Those passive safety phenomena are expected to be assessed using the WCOBRA/TRAC-TF2 LOCA thermal hydraulic code, which will provide the design basis LOCA analysis in the SMR design control documentation. In this paper, the progress on the assessing two key phenomena in passive safety of Westinghouse SMR is reported. The preliminary assessments against UCB tube condensation tests and Westinghouse core makeup tank tests reveals the capability of WCOBRA/TRAC-TF2 code to reasonably predict the condensation on the containment wall and natural circulation in the core makeup tank (CMT) loop.

scholarly journals INVESTIGASI KARAKTERISTIK TERMOHIDROLIKA TERAS REAKTOR DAYA KECIL DENGAN PENDINGINAN SIRKULASI ALAM MENGGUNAKAN RELAP5

2016 ◽  
Vol 18 (1) ◽  
pp. 1
Author(s):  
Susyadi Susyadi ◽  
Hendro Tjahjono ◽  
Sukmanto Dibyo ◽  
Jupiter Sitorus Pane
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Natural Circulation ◽  
Safety Margin ◽  
Inherent Safety ◽  
Hydraulic Characteristics ◽  
Primary Coolant ◽  
Pressurized Water ◽  
The Core ◽  
Small Modular Reactor

ABSTRAK INVESTIGASI KARAKTERISTIK TERMOHIDROLIKA TERAS REAKTOR DAYA KECIL DENGAN PENDINGINAN SIRKULASI ALAM MENGGUNAKAN RELAP5. Reaktor modular daya-kecil (small modular reactor, SMR) memiliki prospek tinggi untuk dibangun di Indonesia. Keluaran dayanya yang relatif kecil dan disainnya yang kompak serta dapat dikonstruksi secara modular memberikan keunggulan fleksibilitas pembangunan yang lebih baik dibanding reaktor konvensional berdaya besar. Disain sistem reaktor kategori ini sangat bervariasi, salah satu diantaranya adalah jenis reaktor air tekan (pressurized water reactor, PWR) yang menerapkan sirkulasi alamiah pada sistem pendingin primernya. Selain itu reaktor ini juga memiliki teras (core) lebih pendek dibanding PWR konvensional. Dari kedua perbedaan tersebut maka terdapat kemungkinan perbedaan pola perpindahan panas yang dapat berimplikasi terhadap keselamatan secara keseluruhan. Oleh karena itu, pada penelitian ini dilakukan investigasi terhadap karakteristik termohidrolika teras reaktor tersebut khususnya karakteristik temperatur fluida dan bahan bakar serta laju alir fluidanya. Tujuannya adalah untuk mengetahui perbedaan marjin keselamatan temperatur teras reaktor bila dibanding dengan PWR konvensional. Investigasi dilakukan dengan menggunakan program RELAP5, dimana secara parsial teras reaktor dimodelkan menggunakan model-model generik yang ada pada program dan dilakukan beberapa perhitungan kondisi tunak. Hasil perhitungan menunjukkan bahwa saat beroperasi pada daya nominalnya, reaktor modular ini memiliki margin temperatur pendidihan sebesar 2K lebih baik dibanding reaktor konvensional. Selain itu, keunggulan marjin keselamatan reaktor modular daya-kecil ini juga ditunjukkan dari naiknya laju alir mengikuti kenaikan dayanya yang berarti memiliki sifat keselamatan yang melekat (inherent safety). Kata kunci: reaktor modular daya-kecil, PWR, sirkulasi alam, RELAP5, termohidrolika   ABSTRACT INVESTIGATION ON CORE THERMAL HYDRAULIC CHARACTERISTICS OF SMALL MODULAR REACTOR WITH NATURAL CIRCULATION COOLING USING RELAP5. Small modular reactor (SMR ) is very prospective to be deployed in Indonesia. Its low output power, compact design and capability to be constructed modularly provide better deployment flexibility compared to a large conventional reactor. There are various designs of SMRs, one of them implements natural circulation for its primary cooling system or in other words the reactor uses no primary pumps. Besides, the dimension of fuel element is shorter than the one used by large reactor. These two aspects may produce different heat transfer behavior, which could lead to a safety implication.  For that reason, this research investigates thermal hydraulic characteristics of the core of SMR with naturally circulating coolant, especially on the fuel and coolant temperatures and mass flow rate. The purpose is to identify the thermal safety margin difference of the reactor compared with conventional PWR.  The investigation was performed using RELAP5 in which the core was partially represented by means of generic models of the program and continued with steady state calculations. The result shows that during nominal power operation, the reactor has better of 2K  degree for boiling temperature margin than the large conventional PWR. In addition, the excellence of SMR safety margin was shown by the increase of primary coolant flow rate following the increase of power, which means that the reactor has a distinctive inherent safety. Keywords: small modular reaktor, PWR, natural circulation, RELAP5, thermal-hydraulic

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