Effect of Regulation Valves Installation in High Pressure Injection System Pipelines on the Formation of Reactor Vessel Thermal Stress Conditions

2014 ◽  
Author(s):  
Aleksander Mazurok ◽  
Maksym Vyshemirskyi
Keyword(s):  
High Pressure ◽  
Thermal Stress ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Stress Conditions ◽  
Severe Accident ◽  
Injection System ◽  
Pressure Injection ◽  
Cooling Water Flow Rate ◽  
High Pressure Injection

Effect of regulation valves (RV) installation in high pressure injection system (HPIS) pipelines on the formation of reactor pressure vessel (RPV) thermal stress conditions was analyzed. Modernization is implemented at South-Ukrainian nuclear power plant (SUNPP) Unit 1 within the framework of life extension, which finished by the end of 2013. The main goal of the modernization is to expand the HPIS functionality for small leak accident and protection against the cold overpressurization due to flow rate and primary pressure effectively regulation. The thermal hydraulic model for RELAP5/mod3.2 code with detailed downcomer (DC) model and changes in accordance with modernization was used for calculations. Detailed (realistic) modeling of piping and equipment was performed. Also, an algorithm for the RVs was developed. Applying of cooling water flow rate regulation avoids excessive primary cooling and, consequently, helps to preserve the RPV integrity and to prevent reaching through crack formation, which can lead to a severe accident.

scholarly journals High Pressure Injection of Chemicals in a Gravel Beach

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 525
Author(s):  
Geng ◽  
Abdollahi-Nasab ◽  
An ◽  
Chen ◽  
Lee ◽  
...  
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Lithium Bromide ◽  
Injection Pressure ◽  
Tidal Range ◽  
Application Of Surfactants ◽  
Pressure Injection ◽  
Oil Biodegradation ◽  
High Pressure Injection ◽  
Gravel Beach

The remediation of beaches contaminated with oil includes the application of surfactants and/or the application of amendments to enhance oil biodegradation (i.e., bioremediation). This study focused on evaluating the practicability of the high pressure injection (HPI) of dissolved chemicals into the subsurface of a lentic Alaskan beach subjected to a 5 m tidal range. A conservative tracer, lithium, in a lithium bromide (LiBr) solution, was injected into the beach at 1.0 m depth near the mid-tide line. The flow rate was varied between 1.0 and 1.5 L/min, and the resulting injection pressure varied between 3 m and 6 m of water. The concentration of the injected tracer was measured from four surrounding monitoring wells at multiple depths. The HPI associated with a flow rate of 1.5 L/min resulted in a Darcy flux in the cross-shore direction at 1.15 × 10−5 m/s compared to that of 7.5 × 10−6 m/s under normal conditions. The HPI, thus, enhanced the hydraulic conveyance of the beach. The results revealed that the tracer plume dispersed an area of ~12 m2 within 24 h. These results suggest that deep injection of solutions into a gravel beach is a viable approach for remediating beaches.

Assessment of MELCOR 1.8.5 Versus Different Versions of SCDAP/RELAP5 MOD 3.3 With Lower Head Creep Rupture Analysis of Alternative Accident Sequences of the Three Mile Island Unit 2

2004 ◽  
Author(s):  
Sang Lung Chan
Keyword(s):  
Flow Rate ◽  
Creep Rupture ◽  
Injection System ◽  
Base Case ◽  
Head Penetration ◽  
Pressure Injection ◽  
Lower Head ◽  
High Pressure Injection ◽  
Accident Sequences ◽  
Head Temperature

The objective of this analysis is to assess MELCOR 1.8.5-RG against SCDAP/RELAP5 MOD 3.3kz (SR5m33kz), and SCDAP/RELAP5 MOD 3.3bf (SR5m33bf). This lower head creep rupture analysis considers: (1) Three Mile Island Unit 2 (TMI-2) alternative accident sequence-1, and (2) TMI-2 alternative accident sequence-2. SCDAP/RELAP5 model of TMI-2 alternative accident sequence-1 includes the continuation of the base case of the TMI-2 accident with the reactor coolant pumps (RCP) tripped, and the High Pressure Injection System (HPIS) throttled after approximately 6000 s accident time, SCDAP/RELAP5 model of TMI-2 alternative accident sequence-2 is derived from the TMI-2 base case accident by tripping the RCP after 6000 s, and the HPIS is reactivated after 12,012 s. MELCOR model of TMI-2 alternative accident sequence-1 is based on MELCOR TMI-2 phase-2 model by tripping the RCP and throttling back the makeup flows to zero from 6000 s onward. In MELCOR model of TMI-2 alternative accident sequence-2, the RCP are tripped from 6000 s and the constant makeup flow rate of 3.75 kg/s — including pump seal flow rate, but without HPIS flow rate — is activated from 6000 s and beyond 10440 s. The simulation is run until the lower head wall ruptures. In addition, the lower head penetration failure is also calculated with MELCOR for both TMI-2 alternative accident sequences. Lower head temperature contours calculated with SCDAP/RELAP5 are visualized and animated with open source visualization freeware ‘OpenDX’. Significant findings of the analysis include: (1) the TMI-2 lower head wall fails by creep rupture with either deactivations or activations of the HPIS; (2) for the TMI-2 alternative accident sequence-1 the time to creep rupture calculated with MELCOR 1.8.5-RG, SR5m33kz, and SR5m33bf agrees reasonably; (3) the calculation with MELCOR for the TMI-2 alternative accident sequence-1 predicts that the lower head wall failure occurred earlier than penetration failure, while MELCOR predicts the opposite for the TMI-2 alternative accident sequence-2; (4) calculation with MELCOR for TMI-2 alternative accident sequence-2 shows that when the lower head wall fails the temperature calculated with MELCOR is 1810.9 K, which exceeds the melting temperature of 1789 K for carbon steel; (5) calculations with both SR5m33kz and SR5m33bf for both TMI-2 alternative accident sequences indicate that different lower head wall locations fail rapidly one after another by a delay of a few seconds, while this is not the case for MELCOR.

A Comprehensive Thermodynamic Approach to Acoustic Cavitation Simulation in High-Pressure Injection Systems by a Conservative Homogeneous Two-Phase Barotropic Flow Model

2005 ◽  
Vol 128 (2) ◽  
pp. 434-445 ◽  
Author(s):  
Andrea E. Catania ◽  
Alessandro Ferrari ◽  
Michele Manno ◽  
Ezio Spessa
Keyword(s):  
High Pressure ◽  
Wave Propagation ◽  
Flow Model ◽  
Acoustic Cavitation ◽  
Injection System ◽  
Pure Liquid ◽  
Two Phase ◽  
Pressure Injection ◽  
Barotropic Flow ◽  
High Pressure Injection

A general conservative numerical model for the simulation of transmission-line unsteady fluid dynamics has been developed and applied to high-pressure injection systems. A comprehensive thermodynamic approach for modeling acoustic cavitation, i.e., cavitation induced by wave propagation, was proposed on the basis of a conservative homogeneous two-phase barotropic flow model of a pure liquid, its vapor, and a gas, both dissolved and undissolved. A physically consistent sound speed equation was set in a closed analytical form of wide application. For the pure-liquid flow simulation outside the cavitation regions, or in the absence of these, temperature variations due to compressibility effects were taken into account, for the first time in injection system simulation, through a thermodynamic relation derived from the energy equation. Nevertheless, in the cavitating regions, an isothermal flow was retained consistently with negligible macroscopic thermal effects due to vaporization or condensation, because of the tiny amounts of liquid involved. A novel implicit, conservative, one-step, symmetrical, and trapezoidal scheme of second-order accuracy was employed to solve the partial differential equations governing the pipe flow. It can also be enhanced at a high-resolution level. The numerical model was applied to wave propagation and cavitation simulation in a high-pressure injection system of the pump-line-nozzle type for light and medium duty vehicles. The system was relevant to model assessment because, at part loads, it presented cavitating flow conditions that can be considered as severe, at least for a diesel injection system. The predicted time histories of pressure at two pipe locations and of injector needle lift were compared to experimental results, substantiating the validity and robustness of the developed conservative model in simulating acoustic cavitation inception and desinence with great accuracy degree. Cavitation transients and the flow discontinuities induced by them were numerically predicted and analyzed.

A Comprehensive Thermodynamic Approach to Acoustic Cavitation Simulation in High-Pressure Injection Systems by a Conservative Homogeneous Barotropic-Flow Model

2003 ◽  
Author(s):  
Andrea E. Catania ◽  
Alessandro Ferrari ◽  
Michele Manno ◽  
Ezio Spessa
Keyword(s):  
High Pressure ◽  
Wave Propagation ◽  
Numerical Model ◽  
Acoustic Cavitation ◽  
Injection System ◽  
Thermodynamic Approach ◽  
Pure Liquid ◽  
Model Assessment ◽  
Pressure Injection ◽  
High Pressure Injection

A general conservative numerical model for simulation of transmission-line unsteady fluid-dynamics has been developed and applied to high-pressure injection systems. A comprehensive thermodynamic approach for modeling acoustic cavitation, i.e. cavitation induced by wave propagation, was proposed on the basis of a homogeneous barotropic mixture model of a pure liquid in equilibrium with its vapor and a gas, both dissolved and undissolved. For the pure liquid flow simulation outside the cavitation regions, or in the absence of these, temperature variations due to compressibility effects were taken into account, for the first time in injection system simulation, through a thermodynamic state equation which was derived from energy considerations. Nevertheless, in the cavitation regions, an isothermal flow was retained which is consistent with negligible thermal effects due to vaporization because of the tiny amounts of liquid involved. A novel implicit, conservative, one step, symmetrical and trapezoidal scheme of the second-order accuracy was applied to solve the hyperbolic partial differential equations governing the pipe flows. It can also be enhanced at a high-resolution level. The numerical model was applied to wave propagation and cavitation simulation in a high-pressure injection system of the pump-line-nozzle type for light and medium duty vehicles. The system was of relevance to the model assessment because it presented severely cavitating flow conditions. The predicted pressure time histories at two pipe locations and injector needle lift were compared to experimental results, substantiating the validity and robustness of the developed conservative model in simulating cavitation inception and desinence with great degree of accuracy. Cavitation transients and the flow discontinuities induced by them were numerically analyzed and discussed.

Analysis of PWR RPV lower head SBLOCA scenarios with the failure of high-pressure injection system using MAAP5

2014 ◽  
Vol 77 ◽  
pp. 48-64 ◽  
Author(s):  
Wei Li ◽  
Xiaoli Wu ◽  
Yapei Zhang ◽  
Deyou Ma ◽  
Yongzheng Chen ◽  
...  
Keyword(s):  
High Pressure ◽  
Injection System ◽  
Pressure Injection ◽  
Lower Head ◽  
High Pressure Injection
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