Mechanical and Hydraulic Loads on the Supports of the Rotary Machine Due to Shaft Seizure in a Nuclear Power Plant

2004 ◽  
Author(s):  
S. K. Gupta ◽  
B. Chatterjee ◽  
Rajesh Kumar
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Heat Transport ◽  
Transport System ◽  
Nuclear Power ◽  
Inertial Load ◽  
Secondary System ◽  
Rotating Shaft ◽  
Rotary Machine ◽  
Major Equipment

In a nuclear power plant there are two major equipment with high mechanical inertia, which have a rotating shaft. These are Pumps in the Primary Heat Transport System and Turbine in the secondary system. In both cases, the shaft seizure leads to transfer of very large loads to the supports. These supports, if not designed for seizure loads may fail. If the supports fail, there is a good possibility of a missile generated and hit the safety equipment. Seizure loads in these machines have three components namely mechanical inertial load, electrical load and hydraulic load. While the electrical and hydraulic loads have a limited peak value, the inertial load depends on the seizure time. For the normal observed seizures the three have a similar order of magnitude during seizure. As the casing is overdesigned the combined load is experienced by the supports. The pump of the Primary Heat Transport System (PHTS) of a nuclear power plant is centrifugal type run by an induction motor. If the pump shaft seizes, the seizure load will be experienced by the support structure. Due to the presence of the flywheel, the total moment of inertia of the pump motor assembly is quite high. Hence the resisting torque may be higher than the support’s design torque. Besides, the electric torque will continue to be applied as the motor trip on the overload current is delayed by several seconds as the corresponding relay is a thermal relay. Seizure torque will depend on pump seizure time. Lesser the seizure time, higher would be the load on the pump supports. The turbine in the secondary system has a large inertia due to blades. In case of a seizure the generator is tripped in hundreds of milliseconds. The load experienced by turbine supports due to seizure is significantly enhanced in the first few seconds due to sustained steam supply before it is cut off. This paper discusses the estimation of the three types of loads during seizure of the shafts in the pumps and turbine. It also discusses the possible safety consequences of these loads.

scholarly journals The Heat Transport System in a Heavy Water Nuclear Reactor

2021 ◽  
Author(s):  
Arber Puci
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Heat Transport ◽  
Transport System ◽  
Nuclear Power ◽  
Nuclear Reactor ◽  
Reference Value ◽  
Nuclear Fission ◽  
Fission Reaction ◽  
Control Goal

Nuclear power provided 10% of the world's electricity. In Ontario Nuclear provides the base electrical load on the grid. Nuclear power is very unique. It is able to release a tremendous amount of power if it is not controlled properly. There is three objectives that are required to be meet at all times when running a Nuclear power plant. These are called the three C’s. The three C’s are Control, Cool and Contain. The nuclear reaction in a power plant is required to be controlled, at all times. This is completed by maintaining the nuclear fission reaction in the reactor. The Nuclear fission reaction releases radioactivity. This radioactivity needs to be contained in the reactor and not released in the environment, at any cost. The reactor is required to be cooled at all times. This report will provide a basis on controlling the heat on a nuclear reactor. This design of the Instrumentation and Control of the Heat Transport System for a CANDU REACTOR, will be discussed in detail in this report. The Heat transport system is responsible to maintain the coolant mass balance of the nuclear power plant. The main control goal is to stabilize the water level at a reference value and to suppress the effect of various disturbances.

Optimal Main Heat Transport system configuration for a nuclear power plant

2020 ◽  
Vol 359 ◽  
pp. 110474
Author(s):  
Avinash J. Gaikwad ◽  
Naresh K. Maheshwari ◽  
K. Obaidurrahman ◽  
Aniket Gupta ◽  
Santosh K. Pradhan
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Heat Transport ◽  
Transport System ◽  
Nuclear Power ◽  
System Configuration

scholarly journals Effect of Coolant Inventories and Parallel Loop Interconnections on the Natural Circulation in Various Heat Transport Systems of a Nuclear Power Plant during Station Blackout

2008 ◽  
Vol 2008 ◽  
pp. 1-11 ◽  
Author(s):  
Avinash J. Gaikwad ◽  
P. K. Vijayan ◽  
Sharad Bhartya ◽  
Kannan Iyer ◽  
Rajesh Kumar ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Heat Transport ◽  
Nuclear Power ◽  
Natural Circulation ◽  
Heat Removal ◽  
Transport Systems ◽  
Critical Examination ◽  
Decay Heat ◽  
Station Blackout

Provision of passive means to reactor core decay heat removal enhances the nuclear power plant (NPP) safety and availability. In the earlier Indian pressurised heavy water reactors (IPHWRs), like the 220 MWe and the 540 MWe, crash cooldown from the steam generators (SGs) is resorted to mitigate consequences of station blackout (SBO). In the 700 MWe PHWR currently being designed an additional passive decay heat removal (PDHR) system is also incorporated to condense the steam generated in the boilers during a SBO. The sustainability of natural circulation in the various heat transport systems (i.e., primary heat transport (PHT), SGs, and PDHRs) under station blackout depends on the corresponding system's coolant inventories and the coolant circuit configurations (i.e., parallel paths and interconnections). On the primary side, the interconnection between the two primary loops plays an important role to sustain the natural circulation heat removal. On the secondary side, the steam lines interconnections and the initial inventory in the SGs prior to cooldown, that is, hooking up of the PDHRs are very important. This paper attempts to open up discussions on the concept and the core issues associated with passive systems which can provide continued heat sink during such accident scenarios. The discussions would include the criteria for design, and performance of such concepts already implemented and proposes schemes to be implemented in the proposed 700 MWe IPHWR. The designer feedbacks generated, and critical examination of performance analysis results for the added passive system to the existing generation II & III reactors will help ascertaining that these safety systems/inventories in fact perform in sustaining decay heat removal and augmenting safety.

Coupling of RELAP and LabVIEW to Model a Nuclear Power Plant System Realistically

2014 ◽  
Author(s):  
J. C. Pack ◽  
Z. Fu ◽  
F. Aydogan
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Virtual Instrument ◽  
Nuclear Power ◽  
System Modeling ◽  
Loop Model ◽  
Secondary System ◽  
Loss Of Coolant Accident ◽  
Accident Scenarios ◽  
Computer Simulators

Within the study and design of a nuclear power plant extensive system modeling is necessary to determine how the reactor is going to perform in any given situation, not only in the normal performance of the reactor but also transients including unanticipated transients without scram and hypothetical accidents. One of the difficulties in the performance of this modeling is that there are often separate programs used to model the primary and other loops in multiple loop systems. When the modeling requires no interaction between the loops, this method is adequate but in many of these scenarios an understanding of the interaction loops is crucial especially in the case of transients including accident scenarios. However, each loop is generally modeled individually and there is no feedback effect between loops. The purpose of this article is to demonstrate how this coupling between the primary and secondary system of a typical PWR can be performed. The primary and secondary sides of the PWR are modeled with Reactor Excursion and Leak Analysis Program (RELAP5) and Laboratory Virtual Instrument Engineering Workbench (LabVIEW) computer simulators respectively. Primary loop model includes a four loops PWR. The coupling between RELAP5 and LabVIEW has been executed with steady state and transients, in this case a loss of coolant accident (LOCA). The results of the coupling have been compared with the typical RELAP5 results without coupling.

Dynamic Simulation on Secondary System of Nuclear Power Plant

2012 ◽  
Vol 591-593 ◽  
pp. 620-625 ◽  
Author(s):  
Rui Yu ◽  
Shi Wei Yao ◽  
Chun Guo Wang
Keyword(s):  
Steady State ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Dynamic Simulation ◽  
Nuclear Power ◽  
Large Scale ◽  
Simulation Models ◽  
Secondary System ◽  
Actual System ◽  
Moisture Separator

The secondary system of Qinshan phase I nuclear power plant is simulated in this study. According to the characteristics of the JTopmeret model, the system is divided into six parts for modeling, which are the deaerator, the high pressure (HP) turbine, the low pressure (LP) turbine, the moisture separator reheater (MSR), the condensate system, and the feedwater system. All parts are built as the graphic automatic models in JTopmeret and debugged on the large-scale simulation platform GSE to complete the steady-state and dynamic simulation of the models. The results show that the steady-state and dynamic processes of the models are consistent with the characteristics of the actual system. It verifies the correctness of the simulation models. Thus, this research is able to provide guidance for the operation analysis and the equipment debugging of the secondary system of the nuclear power plant.

Analysis on Control Operating Conditions of Water Chemistry of Nuclear Power Unit

2012 ◽  
Vol 178-181 ◽  
pp. 553-556
Author(s):  
Wei Li ◽  
Jian Feng Li
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Working Condition ◽  
Operating Conditions ◽  
Effective Control ◽  
Primary System ◽  
Secondary System ◽  
Whole Plant

Hydrochemical working condition of nuclear power plant relates to the safety, stability and economical operation of the whole plant. In view of radioactive factors, it is very important to analyze, identify and supervise the chemical control working condition. Based on AP1000 cases, this article analyzes issues through elaborating the primary system and the secondary system of nuclear power plant, especially the hydrochemical control of steam generator, and then takes targeted and effective control methods to provide references for the future nuclear power plants.

scholarly journals Analysis of Wall-Thinning Effects Caused by Power Uprates in the Secondary System of a Nuclear Power Plant

2016 ◽  
Vol 15 (3) ◽  
pp. 135-140
Author(s):  
Hun Yun ◽  
Kyeongmo Hwang ◽  
Hyoseoung Lee ◽  
Seung-Jae Moon
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Secondary System ◽  
Wall Thinning
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