Vulnerability of Nuclear Power Plants to Voltage Sag Induced by Disturbances in the Transmission Grid: The Concept of Zone of Vulnerability for Voltage

2009 ◽  
Author(s):  
Nick Abi-Samra ◽  
Alberto Del Rosso ◽  
Frank Rahn
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Plant ◽  
Voltage Sag ◽  
Voltage Sags ◽  
Diesel Generator ◽  
Power Station ◽  
Transmission Grid ◽  
Nuclear Plants ◽  
Different Types

Nuclear plants are particularly sensitive to events on the grid that may lead to undervoltage on the auxiliary or safety buses. Momentary voltage dips can cause separation from offsite power and operation of emergency diesel generator. Grid disturbances that occur in certain areas or “zones” in the surrounding network, may affect the operation of the nuclear plant, while disturbances from outside these zones may be cause no threat to the nuclear plant. A zone inside which a nuclear power station would be vulnerable to events on the surrounding grid can be defined as the Zone of Vulnerability (ZoV). Different types of ZoVs can be defined depending on the nature of the vulnerability being considered. This paper deals specifically with the Zone of Vulnerability associated with the risk of voltage sags in the safety and auxiliary for safety and auxiliary buses of nuclear plants induced by faults in the power grid. The paper first introduces the concept of ZoV_v and its importance for nuclear plants security. A methodology for determining the ZoV_v is then described.

Methodology to Evaluate Nuclear Power Plant Vulnerability to Events in the Transmission Grid

2014 ◽  
Author(s):  
Alberto Del Rosso ◽  
Jean-François Roy ◽  
Frank Rahn ◽  
Alejandro Capara
Keyword(s):  
Risk Assessment ◽  
Nuclear Power ◽  
Power Plants ◽  
Assessment Tool ◽  
Transmission Grid ◽  
Simulation Tools ◽  
Nuclear Plants ◽  
Western Electricity Coordinating Council ◽  
The Impact ◽  
The U.S

This paper presents a general approach to evaluate the risk of trip or Loss of Off-site Power (LOOP) events in nuclear power plants due to contingencies in the power grid. The proposed methodology is based on the Zone of Vulnerability concept for nuclear plants introduced by EPRI in previous work. The proposed methodology is intended to be part of an integrated probabilistic risk assessment tool that is being developed under ongoing EPRI R&D programs. A detailed analysis of many events occurred in actual nuclear plants has been performed in order to identify, classify and characterize the various vulnerability and type of failures that may affect a nuclear plant. Based the outcome of that analysis, a methodology for evaluating the impact of off-site transmission system events on nuclear plants has been outlined. It includes description of the type of contingencies and conditions that need to be included in the analysis, as well as provisions regarding the simulation tools and models that should be used in each case. The methodology is illustrated in a simplified representation of the Western Electricity Coordinating Council (WECC) system in the U.S.

Conceptual Design of a 4 × 300 MW Modular Nuclear Plant

2011 ◽  
Author(s):  
Asko Vuorinen
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Plant ◽  
Medium Size ◽  
Modular Construction ◽  
Construction Costs ◽  
University Of Technology ◽  
Nuclear Plants ◽  
Original Estimate ◽  
Under Construction

The Finnish companies have built four medium size nuclear power plants. In addition they have constructed two nuclear icebreakers and several floating power plants. The latest 1650 MWe nuclear power plant under construction Olkiluoto-3 has had many problems, which have raised the costs of the plant to €3500/kWe from its original estimate of €2000/kWe and constriction schedule from four to eight years. It is possible to keep the costs down and schedule short by making the plant in shipyard and transport it to site by sea. The plant could be then lifted to its place by pumping seawater into the channel. This kind of concept was developed by the author in 1991, when he was making his thesis of modular gas fired power plants in Helsinki University of Technology. The modular construction of nuclear plants has made in a form of two nuclear icebreakers, which Wa¨rtsila¨ Marine has built in Helsinki Shipyard. The latest modular nuclear plant was launched in 2010 in St Petersburg shipyard. One of the benefits of modular construction is a possibility to locate the plant under rock by making the transportation channels in tunnels. This will give the plant external protection for aircraft crash and make the outer containment unnecessary. The water channels could also be used as pressure suppression pools in case of venting steam from the containment. This could reduce the radioactive releases in case of possible reactor accidents. The two 440 MW VVER plants build in Finland had construction costs of €1600 /kWe at 2011 money. The author believes that a 1200 MW nuclear plant with four 300 MW units can be constructed in five years and with €3300/kW costs, where the first plant could be generating power within 40 months and next units with 6 month intervals.

A New Paradigm: Cycling Operations at Nuclear Power Plants in the United States

2014 ◽  
Author(s):  
Douglas Hilleman ◽  
Nikhil Kumar ◽  
Steven Lefton
Keyword(s):  
United States ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
The United States ◽  
Nuclear Plant ◽  
New Paradigm ◽  
Load Following ◽  
Nuclear Plants ◽  
Relative Damage

Nuclear power plants are no longer immune to cycling operation. While certain nuclear power plants in Europe have been performing load following operation, this type of operation has largely been avoided in the United States. Due to increasing contribution of nuclear generation in the mix, European operators were forced to make modifications to increase the maneuverability of their nuclear generation assets. However, in the United States, nuclear generation is still a relatively smaller contributor (19%). Still, with rapid increase in renewable generation, some nuclear plants are being asked to operate at reduced power and cycle to lower power levels. With most future renewable integration studies advocating for increased flexibility on the grid, nuclear generation maneuverability will allow system operators with another resource to mitigate system costs. This paper presents the results of a detailed study of a 1,150 MW boiling water reactor nuclear plant when cycled to low loads. The authors present the relative damage of cycling to various reduced power levels 80% to 15% power levels compared to a cold startup and shutdown of a nuclear plant. An assessment was made of the systems that had fatigue damage and costs. We also discuss some of the limitations of cycling that a nuclear plant has and present and discuss recommendations to reduce damage and costs.

scholarly journals Application of Explosion-Proof RFID Technology in Nuclear Power Plants

2020 ◽  
Vol 20 (2) ◽  
pp. 127-132
Author(s):  
Namjin Cho ◽  
Dongsu Im ◽  
Jungdon Kwon ◽  
Teayeon Cho ◽  
Junglim Lee
Keyword(s):  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Ignition Source ◽  
Rfid Technology ◽  
Nuclear Plants ◽  
Frequency Identification

Nuclear power plants store and use flammable gases and liquids and consequently risk explosions. Therefore, nuclear plants employ explosion-proof equipment; however, this equipment is not always sufficiently maintained. This lack of maintenance can affect the safety-related equipment intended to shut down the reactor, because the explosion-proof equipment itself can act as an ignition source. Radio-frequency identification (RFID) technology should be explored as a tool to improve both the convenience and efficiency of maintenance. We analyzed and compared explosion-proof RFID technology that can be used in nuclear power plants.

Evaluation on Radiological Consequence Induced by MSLB Accident With Alternative Source Term

2010 ◽  
Author(s):  
Jingxi Li ◽  
Gaofeng Huang ◽  
Lili Tong
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Source Term ◽  
Control Room ◽  
Power Station ◽  
Alternative Source ◽  
Radiological Consequence

The major threat that nuclear power plants (NPPs) pose to the safety of the public comes from the large amount radioactive material released during design-basis accidents (DBAs). Additionally, many aspects of Control Room Habitability, Environmental Reports, Facility Siting and Operation derive from the design analyses that incorporated the earlier accident source term and radiological consequence of NPPs. Depending on current applications, majority of Chinese NPPs adopt the method of TID-14844, which uses the whole body and thyroid dose criteria. However, alternative Source Term (AST) are commonly used in AP1000 and some LWRs (such as Beaver Valley Power Station, Units No. 1 and No. 2, Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 And 2, Kewaunee Power Station and so on), so it is attempted to adopt AST in radiological consequence analysis of other nuclear power plants. By introducing and implementing the method of AST defined in RG 1.183 and using integral safety analysis code, a pressurized water reactor (PWR) of 900 MW nuclear power plant analysis model is constructed and the radiological consequence induced by Main Steam Line Break (MSLB) accident is evaluated. For DBA MSLB, the fractions of core inventory are assumed to be in the gap for various radionuclides and then the release from the fuel gap is assumed to occur instantaneously with the onset of assumed damage. According to the assumptions for evaluating the radiological consequences of PWR MSLB, dose calculation methodology is performed with total effective dose equivalent (TEDE) which is the criteria of dose evaluation. Compared with dose criteria of RG 1.183, the dose of control room, exclusion area boundary and outer boundary of low population zone are acceptable.

The Need for Strategic Planning for Nuclear Power Plant I&C Upgrades

2002 ◽  
Author(s):  
J. Douglas Hill ◽  
Paul Moore
Keyword(s):  
Strategic Planning ◽  
Control Systems ◽  
Digital Technology ◽  
Nuclear Power ◽  
Power Plants ◽  
Short Term ◽  
Nuclear Plants ◽  
And Control ◽  
Plant Control

Nuclear power plants rely on Instrumentation and Control (I&C) systems for control, monitoring and protection of the plant. The original, analog designs used in most nuclear plants have become or soon will be obsolete, forcing plants to turn to digital technology. Many factors affect the design of replacement equipment, including long-term and short-term economics, regulatory issues, and the way the plant operates on a day-to-day basis. The first step to all modernization projects should involve strategic planning, to ensure that the overall long and short-term goals of the plant are met. Strategic planning starts with a thorough evaluation of the existing plant control systems, the available options, and the benefits and consequences of these options.

Economic Evaluation of Proactive Replacement of Upper Internals Guide Tube Support Pins (Split Pins)

2005 ◽  
Author(s):  
Robert K. Perdue ◽  
G. Gary Elder ◽  
Gregory Gerzen
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Net Present Value ◽  
Time To Failure ◽  
Guide Tube ◽  
Reliability Modeling ◽  
Nuclear Plants ◽  
Zinc Addition ◽  
Primary Water ◽  
The Impact

Certain nuclear power plants have “Rev B” reactor vessel upper internals guide tube support pins, commonly referred to as split pins, made from material with properties similar to Alloy 600 and known to be susceptible to primary water stress corrosion cracking (PWSCC). This paper describes a rigorous probabilistic methodology for evaluating the economics of a preemptive replacement of these split pins, and describes an application at four of Exelon Generation’s nuclear plants. The method uses Bayesian statistical reliability modeling to estimate a Weibull time-to-failure prediction model using limited historical failures, and a Westinghouse proactive aging management simulation tool called PAM to select a split pin replacement date that would maximize the net present value of cash flow to a plant. Also in this study is a sensitivity evaluation of the impact of zinc addition on split pin replacement timing. Plant decisions made based in part on results derived from applying this approach are noted.

Analysis of Cured-in-Place Piping for a Nuclear Plant Application

2011 ◽  
Author(s):  
Alton Reich ◽  
Victor Newman ◽  
Roberto Di Salvo ◽  
John Charest
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Analytical Approach ◽  
Structural Integrity ◽  
Nuclear Plant ◽  
Operating Pressure ◽  
Repair Technique ◽  
Pressure Pipe ◽  
Case Basis ◽  
Design Challenges

Cured-in-place piping (CIPP) is used to repair existing pressure pipe that has compromised structural integrity and is no longer capable of holding operating pressure without leaking. It is often used to repair buried piping where digging the piping up to replace it would be inconvenient and/or cost prohibitive. CIPP is routinely used to repair water and sewer lines, and an ASTM specification exists to guide the design of the pipe repair for these applications. CIPP can also be used as a repair technique for piping at nuclear power plants; however, such use must be approved on a case-by-case basis. This paper discusses some of the design challenges associated with designing the CIPP for a nuclear plant application. It presents an overview of the analytical approach and the results.

Study on PRA Procedure Considering Combination of Multiple Events Using DQFM Methodology

2018 ◽  
Author(s):  
Hirohisa Yamakawa ◽  
Hitoshi Muta
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Seismic Event ◽  
Seismic Events ◽  
Power Station ◽  
Component Failure ◽  
Multiple Events ◽  
Fukushima Daiichi ◽  
Tsunami Event ◽  
Direct Quantification

Fukushima Daiichi Nuclear Power Station accident occurred by the Great East Japan Earthquake on March 11, 2011. After that, continuous enhancement of nuclear safety is being required in Japan. The accident of Fukushima was caused by the seismic induced tsunami event, namely, multiple events. The other examples of multiple events due to the seismic event are such as internal fire and internal flooding in the nuclear power plants. In addition, structures, such as a building, and piping might be damaged by the seismic event, which could impact component failure dependently. In order to consider these kinds of events, the development of PRA procedures for multiple events caused by the seismic events will be highly demanded. So, we developed a basic PRA methodology for seismic induced tsunami events using “Direct Quantification of Fault Tree using Monte Carlo simulation (DQFM) methodology”. And we verified its applicability through the evaluation.

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