Simulation of Loss of RHR During Midloop Operations and the Role of Steam Generators in Decay Heat Removal Using the RELAP5/MOD3 Code

1993 ◽  
Vol 103 (3) ◽  
pp. 310-319 ◽  
Author(s):  
Yassin A. Hassan ◽  
Laxminarayan L. Raja
Keyword(s):  
Heat Removal ◽  
Steam Generators ◽  
Decay Heat

scholarly journals Preliminary Assessment of Decay Heat Removal Systems in the ESFR-SMART Design: The Role of Natural Air Convection Around Steam Generators Outer Shells in Accidental Conditions

2020 ◽  
Author(s):  
Jeremy Bittan ◽  
Clement Bore ◽  
Joel Guidez
Keyword(s):  
Natural Circulation ◽  
Heat Removal ◽  
Steam Generators ◽  
Preliminary Assessment ◽  
Safety Criterion ◽  
Safety Level ◽  
Decay Heat ◽  
Air Convection ◽  
The Impact

Abstract In the frame of the ESFR-SMART European project, aiming at improving the safety level of the European Sodium cooled Fast Reactor (ESFR), this paper presents the preliminary assessment of decay heat removal systems in the ESFR-SMART design: the role of natural air convection around Steam Generators outer shells in accidental conditions. Both theoretical and CATHARE code (Thermal Hydraulics reference code) calculations are presented. The impact of an additional chimney at the top of each casing as well as running primary and secondary pumps on the heat removal capacity are equally evaluated. This paper shows that the evacuation of decay heat thanks to completely passive air natural circulation alone, in case of Fukushima like accident, should lead to temperatures of sodium in the reactor vessel temporarily exceeding the safety criterion of 650°C. The addition of chimneys increase the capacities but is not sufficient to evacuate the decay heat safely. If the primary and secondary side pumps are running, the safety criterion should be met.

3D CFD simulation of passive decay heat removal system under boiling conditions: Role of bubble sliding motion on inclined heated tubes

2016 ◽  
Vol 145 ◽  
pp. 245-265 ◽  
Author(s):  
Nitin Minocha ◽  
Jyeshtharaj Bhalchandra Joshi ◽  
Arun Kumar Nayak ◽  
Pallipattu Krishnan Vijayan
Keyword(s):  
Cfd Simulation ◽  
Heat Removal ◽  
Decay Heat ◽  
Sliding Motion ◽  
Heat Removal System ◽  
Removal System

Simulation Model of a Passive Decay Heat Removal System for Lead-Cooled Fast Reactors

2012 ◽  
Author(s):  
Lorenzo Damiani ◽  
Alessandro Pini Prato
Keyword(s):  
Fast Reactor ◽  
Heat Removal ◽  
Coolant Temperature ◽  
Feed Water ◽  
Steam Generators ◽  
Fast Reactors ◽  
Primary Coolant ◽  
Reaction Heat ◽  
Generator System ◽  
Decay Heat

The generation IV lead cooled fast reactors are of particular interest for the Italian research: several influential companies (Ansaldo Nucleare, ENEA) are involved in these important European R&D projects. At present, one significant European project in progress is LEADER (Lead cooled European Advanced DEmonstrator Reactor) which includes, among its goals, the construction of a lead-cooled fast reactor demonstrator, ALFRED (Advanced Lead Fast Reactor European Demonstrator). The demonstrator has to include technical solutions that simplify the construction phase and assure full safety in operation; according to the latest guidelines, ALFRED final configuration will be characterized by a secondary loop providing bayonet-tube steam generators. The Authors have addressed the issue of bayonet-tube steam generators proposing the EBBSG (External Boiling Bayonet Steam Generator) system, in which the reaction heat is extracted from the lead by means of coolant under vapor phase. This is possible thanks to an external feed-water boiling, based on the known Loeffler scheme, coupled to the bayonet tube concept. In the present paper, the Authors propose a decay heat removal (DHR) system to match the EBBSG scheme. The DHR system is fully passive, exploiting natural circulation phenomena. The performance of the proposed DHR system is investigated through a Matlab-Simulink model. The results are satisfactory since, according to the simulations, the proposed DHR system is able to keep the primary coolant temperature within a safety range for a sufficient time, avoiding the lead freezing or over-heating.

Simulation Model of a Passive Decay Heat Removal System for Lead-Cooled Fast Reactors

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Lorenzo Damiani ◽  
Alessandro Pini Prato
Keyword(s):  
Fast Reactor ◽  
Natural Circulation ◽  
Heat Removal ◽  
Coolant Temperature ◽  
Feed Water ◽  
Steam Generators ◽  
Fast Reactors ◽  
Primary Coolant ◽  
Reaction Heat ◽  
Decay Heat

The generation IV lead cooled fast reactors are of particular interest for the Italian research: several influential companies (Ansaldo Nucleare, ENEA) are involved in these important European R&D projects. At present, one significant European project in progress is lead cooled European advanced demonstrator reactor (LEADER) which includes, among its goals, the construction of a lead-cooled fast reactor demonstrator, advanced lead fast reactor European demonstrator (ALFRED). The demonstrator has to include technical solutions that simplify the construction phase and assure full safety in operation; according to the latest guidelines, ALFRED final configuration will be characterized by a secondary loop providing bayonet-tube steam generators. The authors have addressed the issue of bayonet-tube steam generators proposing the external boiling bayonet steam generator (EBBSG) system, in which the reaction heat is extracted from the lead by means of coolant under vapor phase. This is possible thanks to an external feed-water boiling, based on the known Loeffler scheme, coupled to the bayonet tube concept. In the present paper, the authors propose a decay heat removal (DHR) system to match the EBBSG scheme. The DHR system is fully passive, exploiting natural circulation phenomena. The performance of the proposed DHR system is investigated through a Matlab-Simulink model. The results are satisfactory since, according to the simulations, the proposed DHR system is able to keep the primary coolant temperature within a safety range for a sufficient time, avoiding the lead freezing or over-heating.

scholarly journals Decay Heat Removal and Transient Analysis in Accidental Conditions in the EFIT Reactor

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Giacomino Bandini ◽  
Paride Meloni ◽  
Massimiliano Polidori ◽  
Maddalena Casamirra ◽  
Francesco Castiglia ◽  
...  
Keyword(s):  
Natural Circulation ◽  
Thermal Power ◽  
Heat Removal ◽  
Normal Operation ◽  
Steam Generators ◽  
Flow Paths ◽  
Decay Heat ◽  
Driven System ◽  
Accelerator Driven System ◽  
Relap5 Code

The development of a conceptual design of an industrial-scale transmutation facility (EFIT) of several 100 MW thermal power based on accelerator-driven system (ADS) is addressed in the frame of the European EUROTRANS Integral Project. In normal operation, the core power of EFIT reactor is removed through steam generators by four secondary loops fed by water. A safety-related decay heat removal (DHR) system provided with four independent inherently safe loops is installed in the primary vessel to remove the decay heat by natural convection circulation under accidental conditions which are caused by a loss-of-heat sink (LOHS). In order to confirm the adequacy of the adopted solution for decay heat removal in accidental conditions, some multi-D analyses have been carried out with the SIMMER-III code. The results of the SIMMER-III code have been then used to support the RELAP5 1D representation of the natural circulation flow paths in the reactor vessel. Finally, the thermal-hydraulic RELAP5 code has been employed for the analysis of LOHS accidental scenarios.

Pre-design of an innovative passive decay heat removal system for ATRIUM AMR-SFR

2021 ◽  
Vol 378 ◽  
pp. 111259
Author(s):  
A. Pantano ◽  
P. Gauthe ◽  
M. Errigo ◽  
P. Sciora
Keyword(s):  
Heat Removal ◽  
Decay Heat ◽  
Heat Removal System ◽  
Removal System

Validation of CATHARE V2.5 Thermal-Hydraulic Code Against Full-Scale PERSEO Tests for Decay Heat Removal in LWRs

2010 ◽  
Author(s):  
Giacomino Bandini ◽  
Paride Meloni ◽  
Massimiliano Polidori ◽  
Calogera Lombardo
Keyword(s):  
Experimental Data ◽  
Heat Exchangers ◽  
Heat Removal ◽  
Full Scale ◽  
Experimental Program ◽  
Decay Heat ◽  
The Past ◽  
Reserve Pool ◽  
Large Water ◽  
Safety Systems

The PERSEO experimental program was performed in the framework of a domestic research program on innovative safety systems with the purpose to increase the reliability of passive decay heat removal systems implementing in-pool heat exchangers. The conceived system was tested at SIET laboratories by modifying the existing PANTHERS IC-PCC facility utilized in the past for testing a full scale module of the GE-SBWR in-pool heat exchanger. Integral tests and stability tests were conducted to verify the operating principles, the steadiness and the effectiveness of the system. Two of the more representative tests have been analyzed with CATHARE V2.5 for code validation purposes. The paper deals with the comparison of code results against experimental data. The capabilities and the limits of the code in simulating such kind of tests are highlighted. An improvement in the modeling of the large water reserve pool is suggested trying to reduce the discrepancies observed between code results and test measurements.

Quality Management during Manufacturing of High Tempertaure Thin Walled Austenitic Stainless Steel Sodium Tanks of Prototype Fast Breeder Reactor

2013 ◽  
Vol 794 ◽  
pp. 507-513
Author(s):  
R.G. Rangasamy ◽  
Prabhat Kumar
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Austenitic Stainless Steel ◽  
Quality Management ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Heat Removal ◽  
Fast Breeder Reactor ◽  
Decay Heat ◽  
Thin Walled

Austenitic stainless steels are the major material of construction for the fast breeder reactors in view of their adequate high temperature mechanical properties, compatibility with liquid sodium coolant, good weldability, availability of design data and above all the fairly vast and satisfactory experience in the use of these steels for high temperature service. All the Nuclear Steam Supply System (NSSS) components of FBR are thin walled structure and require manufacture to very close tolerances under nuclear clean conditions. As a result of high temperature operation and thin wall construction, the acceptance criteria are stringent as compared to ASME Section III. The material of construction is Austenitic stainless steel 316 LN and 304 LN with controlled Chemistry and calls for additional tests and requirements as compared to ASTM standards. Prototype Fast Breeder Reactor (PFBR) is sodium cooled, pool type, 500 MWe reactor which is at advanced stage of construction at Kalpakkam, Tamilnadu, India. In PFBR, the normal heat transport is mainly through two secondary loops and in their absence; the decay heat removal is through four passive and independent safety grade decay heat removal loops (SGDHR). The secondary sodium circuit and the SGHDR circuit consist of sodium tanks for various applications such as storage, transfer, pressure mitigation and to take care of volumetric expansion. The sodium tanks are thin walled cylindrical vertical vessels with predominantly torispherical dished heads at the top and bottom. These tanks are provided with pull-out nozzles which were successfully made by cold forming. Surface thermocouples and heaters, wire type leak detectors are provided on these tanks. These tanks are insulated with bonded mineral wool and with aluminum cladding. All the butt welds in pressure parts were subjected to 100% Radiographic examination. These tanks were subjected to hydrotest, pneumatic test and helium leak test under vacuum. The principal material of construction being stainless steel for the sodium tanks shall be handled with care following best engineering practices coupled with stringent QA requirements to avoid stress corrosion cracking in the highly brackish environment. Intergranular stress corrosion cracking and hot cracking are additional factors to be addressed for the welding of stainless steel components. Pickling and passivation, Testing with chemistry controlled demineralised water are salient steps in manufacturing. Corrosion protection and preservation during fabrication, erection and post erection is a mandatory stipulation in the QA programme. Enhanced reliability of welded components can be achieved mainly through quality control and quality assurance procedures in addition to design and metallurgy. The diverse and redundant inspections in terms of both operator and technique are required for components where zero failure is desired & claimed. This paper highlights the step by step quality management methodologies adopted during the manufacturing of high temperature thin walled austenitic stainless steel sodium tanks of PFBR.

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