WorldWideScience

Sample records for blackouts

  1. Shuttle Communications Blackout Study

    Science.gov (United States)

    Haben, R. L.; Budica, R. J.

    1983-01-01

    Space Shuttle Orbiter Entry Communications Blackout Study computer program models, investigates, and predicts communication blackout envelopes based on mission entry trajectory and associated data from tracking stations. Of interest to those designing and using communications systems susceptible to blackout. Program is readily adapted to predict entry communications blackout for any nonablative entry vehicle.

  2. Alcohol-Induced Blackout

    Directory of Open Access Journals (Sweden)

    Dai Jin Kim

    2009-11-01

    Full Text Available For a long time, alcohol was thought to exert a general depressant effect on the central nervous system (CNS. However, currently the consensus is that specific regions of the brain are selectively vulnerable to the acute effects of alcohol. An alcohol-induced blackout is the classic example; the subject is temporarily unable to form new long-term memories while relatively maintaining other skills such as talking or even driving. A recent study showed that alcohol can cause retrograde memory impairment, that is, blackouts due to retrieval impairments as well as those due to deficits in encoding. Alcoholic blackouts may be complete (en bloc or partial (fragmentary depending on severity of memory impairment. In fragmentary blackouts, cueing often aids recall. Memory impairment during acute intoxication involves dysfunction of episodic memory, a type of memory encoded with spatial and social context. Recent studies have shown that there are multiple memory systems supported by discrete brain regions, and the acute effects of alcohol on learning and memory may result from alteration of the hippocampus and related structures on a cellular level. A rapid increase in blood alcohol concentration (BAC is most consistently associated with the likelihood of a blackout. However, not all subjects experience blackouts, implying that genetic factors play a role in determining CNS vulnerability to the effects of alcohol. This factor may predispose an individual to alcoholism, as altered memory function during intoxication may affect an individual‟s alcohol expectancy; one may perceive positive aspects of intoxication while unintentionally ignoring the negative aspects. Extensive research on memory and learning as well as findings related to the acute effects of alcohol on the brain may elucidate the mechanisms and impact associated with the alcohol- induced blackout.

  3. Modelling, controlling, predicting blackouts

    CERN Document Server

    Wang, Chengwei; Baptista, Murilo S

    2016-01-01

    The electric power system is one of the cornerstones of modern society. One of its most serious malfunctions is the blackout, a catastrophic event that may disrupt a substantial portion of the system, playing havoc to human life and causing great economic losses. Thus, understanding the mechanisms leading to blackouts and creating a reliable and resilient power grid has been a major issue, attracting the attention of scientists, engineers and stakeholders. In this paper, we study the blackout problem in power grids by considering a practical phase-oscillator model. This model allows one to simultaneously consider different types of power sources (e.g., traditional AC power plants and renewable power sources connected by DC/AC inverters) and different types of loads (e.g., consumers connected to distribution networks and consumers directly connected to power plants). We propose two new control strategies based on our model, one for traditional power grids, and another one for smart grids. The control strategie...

  4. Modeling Radio Communication Blackout and Blackout Mitigation in Hypersonic Vehicles

    Science.gov (United States)

    Kundrapu, Madhusudhan; Loverich, John; Beckwith, Kristian; Stoltz, Peter; Shashurin, Alexey; Keidar, Michael

    2015-05-01

    A procedure for the modeling and analysis of radio communication blackout of hypersonic vehicles is presented. The weakly ionized plasma generated around the surface of a hypersonic reentry vehicle is simulated using full Navier-Stokes equations in multi-species single fluid form. A seven species air chemistry model is used to compute the individual species densities in air including ionization - plasma densities are compared with experiment. The electromagnetic wave's interaction with the plasma layer is modeled using multi-fluid equations for fluid transport and full Maxwell's equations for the electromagnetic fields. The multi-fluid solver is verified for a whistler wave propagating through a slab. First principles radio communication blackout over a hypersonic vehicle is demonstrated along with a simple blackout mitigation scheme using a magnetic window.

  5. Modeling radio communication blackout and blackout mitigation in hypersonic vehicles

    CERN Document Server

    Kundrapu, Madhusudhan; Beckwith, Kristian; Stoltz, Peter; Shashurin, Alexey; Keidar, Michael

    2014-01-01

    A procedure for the modeling and analysis of radio communication blackout of hypersonic vehicles is presented. A weakly ionized plasma generated around the surface of a hypersonic reentry vehicle traveling at Mach 23 was simulated using full Navier-Stokes equations in multi-species single fluid form. A seven species air chemistry model is used to compute the individual species densities in air including ionization - plasma densities are compared with experiment. The electromagnetic wave's interaction with the plasma layer is modeled using multi-fluid equations for fluid transport and full Maxwell's equations for the electromagnetic fields. The multi-fluid solver is verified for a whistler wave propagating through a slab. First principles radio communication blackout over a hypersonic vehicle is demonstrated along with a simple blackout mitigation scheme using a magnetic window.

  6. 78 FR 21275 - Station Blackout Mitigation Strategies

    Science.gov (United States)

    2013-04-10

    ...; ] NUCLEAR REGULATORY COMMISSION 10 CFR Parts 50 and 52 RIN 3150-AJ08 Station Blackout Mitigation Strategies... plant licensees' station blackout mitigation strategies. Appendix A of the draft regulatory basis... involving station blackout mitigation strategies, the NRC is making preliminary documents publicly...

  7. Power System Blackouts: Analysis and Simulation of August 9, 2004 Blackout in Jordan Power System

    OpenAIRE

    Abdullah I. Al-Odienat

    2006-01-01

    Large blackouts are usually caused by a complicated sequence of cascading failures. Initial failures weaken the system and cause further failures, which further weaken the system and so on. This study investigates the blackout that occurred on 9th August in the Jordanian Power System. For modeling the blackout, a base case was established by creating a power flow simulation for the system with both of Egypt And Syria links. The analysis shows that the blackout has occurred as a result of full...

  8. Blackouts during navigation in narrow passages

    OpenAIRE

    Roos, Tuomas; Virkkunen, Jerry

    2016-01-01

    This thesis gives you the basic knowledge about the characteristics of blackouts. You will also learn how to react as an officer in a blackout situation. The thesis consists of two parts: theory and research. The theory part will give you details on what a blackout is, details on ship electricity and emergency power sources and above all, things to consider as an officer in a blackout situation. The theory part also includes law text in an easy to understand form. The latter part is a d...

  9. 78 FR 44035 - Station Blackout Mitigation Strategies

    Science.gov (United States)

    2013-07-23

    ... COMMISSION 10 CFR Parts 50 and 52 RIN 3150-AJ08 Station Blackout Mitigation Strategies AGENCY: Nuclear... concerning nuclear power plant licensees' and applicants' station blackout mitigation strategies. The...-415- 4737, or by email to pdr.resource@nrc.gov . The regulatory basis document, ``Station...

  10. 47 CFR 76.128 - Application of sports blackout rules.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Application of sports blackout rules. 76.128... Sports Blackout § 76.128 Application of sports blackout rules. The cable and satellite sports blackout rules (§§ 76.111 and 76.127) may apply when the sports event is not available live on any of...

  11. Blackouts

    Science.gov (United States)

    ... and learn how to operate it. - Keep your car’s gas tank at least half full; gas stations rely on electricity to power their pumps. -Have an extra battery on hand for battery- operated wheelchairs. - Turn off ...

  12. Study on self organized criticality of China power grid blackouts

    International Nuclear Information System (INIS)

    Based on the complex system theory and the concept of self organized criticality (SOC) theory, the mechanism of China power grid blackout is studied by analyzing the blackout data in the China power system from 1981 to 2002. The probability distribution functions of various measures of blackout size have a power tail. The analysis of scaled window variance and rescaled range statistics of the time series show moderate long time correlations. The blackout data seem consistent with SOC; the results obtained show that SOC dynamics may play an important role in the dynamics of power systems blackouts. It would be possible to propose novel approaches for understanding and controlling power systems blackouts

  13. 47 CFR 76.127 - Satellite sports blackout.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Satellite sports blackout. 76.127 Section 76... Sports Blackout § 76.127 Satellite sports blackout. (a) Upon the request of the holder of the broadcast rights to a sports event, or its agent, no satellite carrier shall retransmit to subscribers within...

  14. 47 CFR 76.111 - Cable sports blackout.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Cable sports blackout. 76.111 Section 76.111... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.111 Cable sports blackout. (a) No community unit located in whole or in part within the...

  15. Psychological Consequences of Alcohol Induced Blackout among College Students.

    Science.gov (United States)

    Buelow, George; Koeppel, John

    1995-01-01

    In a college student sample, significant correlations were found between students' alcohol abuse scores, blackout risk taking, and intrusiveness of stressful thoughts about the blackout incident. Men were significantly more likely than women to take risks during the blackout incident and to experience more stressful intrusive thoughts afterward.…

  16. Engaging Honors Students through Newspaper Blackout Poetry

    Science.gov (United States)

    Ladenheim, Melissa

    2014-01-01

    This article describes the author's attempt to convince her students that poetry can be "their thing," and also show them how much it can shape the way they think about the world and their place in it. In this article Melissa Ladenheim describes the technique known as "newspaper blackout" poetry. The exciting thing about this…

  17. Station blackout analysis of natural circulation reactor

    International Nuclear Information System (INIS)

    Full text of publication follows: The natural circulation reactor is a vertical pressure tube type boiling light water cooled and heavy water moderated reactor. One of the important passive design features of this reactor is that the heat removal is achieved through natural circulation of primary coolant at all power level with no primary coolant pumps. There is no auxiliary feed pump available as Isolation Condenser (IC) is meant to remove decay heat. Station Blackout lead to feed water pump trip and loss of condenser vacuum which in turn results in to loss of feed water as well as the turbine trip on low condenser vacuum signal. This leads to bottle up of the system, leading to pressure rise in PHT. The bypass flow is not available due to loss of condenser vacuum. Reactor is tripping on high pressure signal. As the pressure continue to raise, IC valve starts opening at a pressure of 76.0 bar to limit the pressure rise. Relief valve may open in case of IC's capacity is not adequate. This analysis highlights the thermal hydraulic conditions following station blackout with IC's to limit the pressure rise. The paper discusses the thermal hydraulic transient analysis for evaluating the safety of the reactor; following station blackout with IC's using RELAP5/MOD3.2. Predictions are made for different parameters like pressure, temperature, steam quality and flow in different parts of the Primary Heat Transport (PHT) system. In this paper summary of analysis for event is presented. In this paper, various modeling complexities are brought out; evaluation of acceptance criteria is made and design implications of event are discussed. (authors)

  18. Delayed Station Blackout Event and Nuclear Safety

    OpenAIRE

    Andrija Volkanovski; Andrej Prošek

    2015-01-01

    The loss of off-site power (LOOP) event occurs when all electrical power to the nuclear power plant from the power grid is lost. Complete failure of both off-site and on-site alternating current (AC) power sources is referred to as a station blackout (SBO). Combined LOOP and SBO events are analyzed in this paper. The analysis is done for different time delays between the LOOP and SBO events. Deterministic safety analysis is utilized for the assessment of the plant parameters for different tim...

  19. Station blackout calculations for Peach Bottom

    International Nuclear Information System (INIS)

    A calculational procedure for the Station Blackout Severe Accident Sequence at Browns Ferry Unit One has been repeated with plant-specific application to one of the Peach Bottom Units. The only changes required in code input are with regard to the primary containment concrete, the existence of sprays in the secondary containment, and the size of the refueling bay. Combustible gas mole fractions in the secondary containment of each plant during the accident sequence are determined. It is demonstrated why the current state-of-the-art corium/concrete interaction code is inadequate for application to the study of Severe Accident sequences in plants with the BWR MK I or MK II containment design

  20. Delayed Station Blackout Event and Nuclear Safety

    Directory of Open Access Journals (Sweden)

    Andrija Volkanovski

    2015-01-01

    Full Text Available The loss of off-site power (LOOP event occurs when all electrical power to the nuclear power plant from the power grid is lost. Complete failure of both off-site and on-site alternating current (AC power sources is referred to as a station blackout (SBO. Combined LOOP and SBO events are analyzed in this paper. The analysis is done for different time delays between the LOOP and SBO events. Deterministic safety analysis is utilized for the assessment of the plant parameters for different time delays of the SBO event. Obtained plant parameters are used for the assessment of the probabilities of the functional events in the SBO event tree. The results show that the time delay of the SBO after the LOOP leads to a decrease of the core damage frequency (CDF from the SBO event tree. The reduction of the CDF depends on the time delay of the SBO after the LOOP event. The results show the importance of the safety systems to operate after the plant shutdown when the decay heat is large. Small changes of the basic events importance measures are identified with the introduction of the delay of the SBO event.

  1. 17 CFR 245.101 - Prohibition of insider trading during pension fund blackout periods.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Prohibition of insider trading during pension fund blackout periods. 245.101 Section 245.101 Commodity and Securities Exchanges...-Blackout Trading Restriction) § 245.101 Prohibition of insider trading during pension fund blackout...

  2. Reactor coolant pump shaft seal stability during station blackout

    International Nuclear Information System (INIS)

    Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of parameters having the most influence on overall hydraulic seal performance. Predicted seal failure thresholds are presented for a range of station blackout conditions and shaft seal geometries

  3. Natural hazard impact on the technosphere: "blackouts

    Science.gov (United States)

    Petrova, E. G.

    2012-04-01

    In recent years, natural-technological accidents (NTA) and disasters are increasing in their number and severity all over the world. The term "natural-technological accident (disaster)" applies for an accident (disaster) in the technosphere triggered by any natural process or phenomenon. Their growth is caused, on the one hand, by observed increasing in the frequency and intensity of some natural hazards and hazardous events due to climate change and, on the other hand, by a growing complication of the modern technosphere exposed to natural impacts and advancement of economic activities into the area at natural risk. The most large-scaled natural-technological disaster happened on March 11, 2011 in Japan, as a result of a massive earthquake and tsunami that caused a number of serious technological accidents, including accidents at "Fukushima-1" nuclear power plant, etc. Severe social, ecological and economic consequences of large-scaled NTA make investigation of these events especially important. The most frequent among NTA occurring in Russia are breakdowns in electric power supply systems that lead to so-called "blackouts" (accidental power outages). They are mainly caused by strong winds, snowstorms, deposition of ice, sleet, and snow, rainfalls, floods, and hailstones. Among other triggers earthquakes, hard frost, fierce heat, thunderstorms, landslides, snow avalanches, and debris flows should be mentioned. The great part of transmission facilities in Russia falls on overhead lines that are especially vulnerable to natural impacts. In general, natural triggers are responsible for more than 70 percent of all accidents in power supply systems. They occur more often in Far East, in the Southern and North-Western federal districts, and in some regions of the Central Russia, which are prone to hurricanes, cyclones, snowstorms, and heavy rainfalls accompanying by hailstones, icing, and sleet. A distinctive feature of these events is their synergistic nature, as power

  4. Initial Evidence for Self-Organized Criticality in Electric Power System Blackouts

    International Nuclear Information System (INIS)

    We examine correlations in a time series of electric power system blackout sizes using scaled window variance analysis and R/S statistics. The data shows some evidence of long time correlations and has Hurst exponent near 0.7. Large blackouts tend to correlate with further large blackouts after a long time interval. Similar effects are also observed in many other complex systems exhibiting self-organized criticality. We discuss this initial evidence and possible explanations for self-organized criticality in power systems blackouts. Self-organized criticality, if fully confirmed in power systems, would suggest new approaches to understanding and possibly controlling blackouts

  5. Design Provisions for Withstanding Station Blackout at Nuclear Power Plants

    International Nuclear Information System (INIS)

    International operating experience has shown that the loss of off-site power supply concurrent with a turbine trip and unavailability of the standby alternating current power system is a credible event. Lessons learned from the past and recent station blackout events, as well as the analysis of the safety margins performed as part of the ‘stress tests’ conducted on European nuclear power plants in response to the Fukushima Daiichi accident, have identified the station blackout event as a limiting case for most nuclear power plants. The magnitude 9.0 earthquake and consequential tsunami which occurred in Fukushima, Japan, in March 2011, led to a common cause failure of on-site alternating current electrical power supply systems at the Fukushima Daiichi nuclear power plant as well as the off-site power grid. In addition, the resultant flooding caused the loss of direct current power supply, which further exacerbated an already critical situation at the plant. The loss of electrical power resulted in the meltdown of the core in three reactors on the site and severely restricted heat removal from the spent fuel pools for an extended period of time. The plant was left without essential instrumentation and controls, and this made accident management very challenging for the plant operators. The operators attempted to bring and maintain the reactors in a safe state without information on the vital plant parameters until the power supply was eventually restored after several days. Although the Fukushima Daiichi accident progressed well beyond the expected consequences of a station blackout, which is the complete loss of all alternating current power supplies, many of the lessons learned from the accident are valid. A failure of the plant power supply system such as the one that occurred at Fukushima Daiichi represents a design extension condition that requires management with predesigned contingency planning and operator training. The extended loss of all power at a

  6. Station blackout core damage frequency in an advanced nuclear reactor

    International Nuclear Information System (INIS)

    Even though nuclear reactors are provided with protection systems so that they can be automatically shut down in the event of a station blackout, the consequences of this event can be severe. This is because many safety systems that are needed for removing residual heat from the core and for maintaining containment integrity, in the majority of the nuclear power plants, are AC dependent. In order to minimize core damage frequency, advanced reactor concepts are being developed with safety systems that use natural forces. This work shows an improvement in the safety of a small nuclear power reactor provided by a passive core residual heat removal system. Station blackout core melt frequencies, with and without this system, are both calculated. The results are also compared with available data in the literature. (author)

  7. Tarapur atomic power station: analysis of station blackout scenario

    Energy Technology Data Exchange (ETDEWEB)

    Contractor, A.D.; Lele, H.G.; Vaze, K.K. [Bhabha Atomic Research Centre, Mumbai (India). Reactor Safety Division; Srivastava, A.

    2015-03-15

    India is currently operating two BWR built by General Electric Company. The design features of these reactors are similar to the Fukushima's BWR except some better containment features in Indian BWR. This paper discusses the enveloping scenario of station blackout of infinite duration with no operator action and no component failure. The paper describes the details of modelling the TAPS-BWR plant model including SCDAP modelling of reactor core in system code RELAP5 and further thermal hydraulic safety assessment of station blackout scenario. The analysis brought out effectively the response of the plant to this high-pressure severe accident scenario. The time line of the severe accident progression will give details of various stages of accident progression along with hydrogen generation, which will be useful in evolving suitable severe accident management guidelines.

  8. Reactor coolant pump shaft seal behavior during station blackout

    International Nuclear Information System (INIS)

    A testing program designed to provide fundamental information pertaining to the behavior of reactor coolant pump (RCP) shaft seals during a postulated nuclear power plant station blackout has been completed. One seal assembly, utilizing both hydrodynamic and hydrostatic types of seals, was modeled and tested. Extrusion tests were conducted to determine if seal materials could withstand predicted temperatures and pressures. A taper-face seal model was tested for seal stability under conditions when leaking water flashes to steam across the seal face. Test information was then used as the basis for a station blackout analysis. Test results indicate a potential problem with an elastomer material used for O-rings by a pump vendor; that vendor is considering a change in material specification. Test results also indicate a need for further research on the generic issue of RCP seal integrity and its possible consideration for designation as an unresolved safety issue

  9. Analysis of operator response strategies to station blackout

    International Nuclear Information System (INIS)

    A 'Station Blackout' transient in a three-loop PWR nuclear power plant was analyzed by using the RELAP/SCDAPSIM code. A comparison was made of different operator strategies to depressurize the reactor coolant system. The plant response to 'Station Blackout' was evaluated with respect to safety challenges as: size of the radioactive source term, fuel degradation and loss of its coolability, hydrogen production, containment bypass due to creep failure of steam generator tubes. Special attention was given to the thermal load on pressurizer relief valves, since successful implementation of primary side depressurization depends on the valves' reliable operation. The study results indicate that the operator strategy to depressurize the primary system when the core exit temperatures exceed 643 [K] allows to achieve minimum challenges to plant and public safety and provide the longest period of time to restore AC power to the plant engineered safeguards system. (author)

  10. Tarapur atomic power station: analysis of station blackout scenario

    International Nuclear Information System (INIS)

    India is currently operating two BWR built by General Electric Company. The design features of these reactors are similar to the Fukushima's BWR except some better containment features in Indian BWR. This paper discusses the enveloping scenario of station blackout of infinite duration with no operator action and no component failure. The paper describes the details of modelling the TAPS-BWR plant model including SCDAP modelling of reactor core in system code RELAP5 and further thermal hydraulic safety assessment of station blackout scenario. The analysis brought out effectively the response of the plant to this high-pressure severe accident scenario. The time line of the severe accident progression will give details of various stages of accident progression along with hydrogen generation, which will be useful in evolving suitable severe accident management guidelines.

  11. Communications Blackout Predictions for Atmospheric Entry of Mars Science Laboratory

    Science.gov (United States)

    Morabito, David D.; Edquist, Karl

    2005-01-01

    The Mars Science Laboratory (MSL) is expected to be a long-range, long-duration science laboratory rover on the Martian surface. MSL will provide a significant milestone that paves the way for future landed missions to Mars. NASA is studying options to launch MSL as early as 2009. MSL will be the first mission to demonstrate the new technology of 'smart landers', which include precision landing and hazard avoidance in order to -land at scientifically interesting sites that would otherwise be unreachable. There are three elements to the spacecraft; carrier (cruise stage), entry vehicle, and rover. The rover will have an X-band direct-to-Earth (DTE) link as well as a UHF proximity link. There is also a possibility of an X-band proximity link. Given the importance of collecting critical event telemetry data during atmospheric entry, it is important to understand the ability of a signal link to be maintained, especially during the period near peak convective heating. The received telemetry during entry (or played back later) will allow for the performance of the Entry-Descent-Landing technologies to be assessed. These technologies include guided entry for precision landing, hazard avoidance, a new sky-crane landing system and powered descent. MSL will undergo an entry profile that may result in a potential communications blackout caused by ionized plasma for short periods near peak heating. The vehicle will use UHF and possibly X-band during the entry phase. The purpose of this report is to quantify or bound the likelihood of any such blackout at UHF frequencies (401 MHz) and X-band frequencies (8.4 GHz). Two entry trajectory scenarios were evaluated: a stressful entry trajectory to quantify an upper-bound for any possible blackout period, and a nominal likely trajectory to quantify likelihood of blackout for such cases.

  12. Communications Blackout Prediction for Atmospheric Entry of Mars Science Laboratory

    Science.gov (United States)

    Morabito, David; Edquist, Karl

    2005-01-01

    When a supersonic spacecraft enters a planetary atmosphere with v >> v(sub sound), a shock layer forms in the front of the body. An ionized sheath of plasma develops around the spacecraft, which results from the ionization of the atmospheric constituents as they are compressed and heated by the shock or heated within the boundary layer next to the surface. When the electron density surrounding the spacecraft becomes sufficiently high, communications can be disrupted (attenuation/blackout). During Mars Science Laboratory's (MSL's) atmospheric entry there will likely be a communication outage due to charged particles on the order of 60 to 100 seconds using a UHF link frequency looking out the shoulders of the wake region to orbiting relay asset. A UHF link looking out the base region would experience a shorter duration blackout, about 35 seconds for the stressed trajectory and possibly no blackout for the nominal trajectory. There is very little likelihood of a communications outage using X-band (however, X-band is not currently planned to be used during peak electron density phase of EDL).

  13. Mitiiation of Blackout in Kigali Using a Microgrid with Advanced Energy Storage and Solar Photovoltaics

    OpenAIRE

    Karugarama, Marvin Kiiza

    2016-01-01

    A blackout is defined as the loss of electric power for a given period in a particular area. With increasing dependence on reliable electric power, the social and economic ramifications of blackouts are dire, negatively impacting the productivity, safety, and security of communities. To reduce blackout occurrence, power system planners incorporate redundancy and advanced controls to the grid to make it more adaptable to disturbances. However, adding redundant transmission lines is not only ex...

  14. Health Impact in New York City During the Northeastern Blackout of 2003

    Science.gov (United States)

    Lin, Shao; Fletcher, Barbara A.; Luo, Ming; Chinery, Robert; Hwang, Syni-An

    2011-01-01

    Objective This study assessed the health effects of the 2003 Northeastern blackout, the largest one in history, on mortality and hospital admissions due to respiratory, cardiovascular, and renal diseases in New York City (NYC), and compared the disease patterns and sociodemographic profiles of cases during the blackout with those on control days. Method We investigated the effects of the blackout on health using incidence rate ratios to compare the disease on blackout days (August 14 and 15, 2003) with those on normal and comparably hot days (controls). Normal days were defined as summer days (June–August) between the 25th and 75th percentiles of maximum temperature during 1991–2004. Comparably hot days were days with maximum temperatures in the same range as that of the blackout days. We evaluated the interactive effects of demographics and the blackout using a case-only design. Results We found that mortality and respiratory hospital admissions in NYC increased significantly (two- to eightfold) during the blackout, but cardiovascular and renal hospitalizations did not. The most striking increases occurred among elderly, female, and chronic bronchitis admissions. We identified stronger effects during the blackout than on comparably hot days. In contrast to the pattern observed for comparably hot days, higher socioeconomic status groups were more likely to be hospitalized during the blackout. Conclusions This study suggests that power outages may have important health impacts, even stronger than the effects of heat alone. The findings provide some direction for future emergency planning and public health preparedness. PMID:21553667

  15. Areva T and D market opportunities after the US and EU Blackouts

    International Nuclear Information System (INIS)

    This document presents the events on the transmission systems during August 2003 in Usa and in September 2003 in Italy. The author analyzes the causes of the blackouts (small margins in transmission system, not adequate control, weaknesses in interconnections between regions), the market opportunity arising out of the blackouts, the economic regulatory and environmental structure/issues today and developments, the scenario for Areva after the blackout (the market size today and in the future) and Areva strength in relation to blackout. (A.L.B.) opportunities

  16. Station blackout at nuclear power plants: Radiological implications for nuclear war

    International Nuclear Information System (INIS)

    Recent work on station blackout is reviewed its radiological implications for a nuclear war scenario is explored. The major conclusion is that the effects of radiation from many nuclear weapon detonations in a nuclear war would swamp those from possible reactor accidents that result from station blackout

  17. Electrical network reliability and system blackout development simulations

    Science.gov (United States)

    Nepomnyashchiy, V. A.

    2015-12-01

    The main regulations of the author's model of electrical network reliability and system blackout development are stated. The model allows one to analytically determine the main technical and economic parameters indicators of reliability of electrical network operation, taking into account the generating power dislocations and electric loads, operation conditions, and dynamic and static stability of operation, while simultaneously calculating short circuit currents. The model also considers open-phase modes at singlephase short circuits and allows one to choose the most efficient operation conditions. The calculations are finished with an estimate of the annual averages of undersupply of energy and economic losses of customers due to their power supply interruptions.

  18. Station blackout and public confidence: a cautionary tale

    International Nuclear Information System (INIS)

    The recent ''station blackout'' (ie loss of on-site and off-site AC power) incidents at the Vogtle PWR in the US and Hinkley Point B AGR in the Uk have led to further public concern about the safety of nuclear power, even though in each case the actual increase in the chance of an accident leading to a release of radioactivity to the environment was negligible. The industry may be wise to invest precautionary measures to reduce the frequency of such incidents and to increase public confidence. (author)

  19. Reproducing continuous radio blackout using glow discharge plasma

    International Nuclear Information System (INIS)

    A novel plasma generator is described that offers large-scale, continuous, non-magnetized plasma with a 30-cm-diameter hollow structure, which provides a path for an electromagnetic wave. The plasma is excited by a low-pressure glow discharge, with varying electron densities ranging from 109 to 2.5 × 1011 cm−3. An electromagnetic wave propagation experiment reproduced a continuous radio blackout in UHF-, L-, and S-bands. The results are consistent with theoretical expectations. The proposed method is suitable in simulating a plasma sheath, and in researching communications, navigation, electromagnetic mitigations, and antenna compensation in plasma sheaths

  20. Safety aspects of station blackout at nuclear power plants

    International Nuclear Information System (INIS)

    The principal focus of this report is on existing light water reactor nuclear power plants. However, many of the considerations discussed herein can be equally applied to new plants, i.e. those not yet in construction. This report is organized to provide a description of design and procedural factors which safety assessments and reviews of operating experience have shown to be important. These are divided into the off-site power system, the on-site AC power systems and alternate (or nearby) sources of power. The latter may be used in the unlikely event that both normal off-site and on-site sources fail. It must be emphasized that first priority should be placed on designing and maintaining high reliability of both the off-site and on-site AC power systems. This basic concept also applies to the capabilities for restoring power sources which failed and making use of all available alternative and nearby power sources during an emergency, to restore AC power in a prompt manner. Discussions on these aspects are provided in chapters 2 and 3 of this report. Because the expected event frequency and associated confidence in such estimations of station blackout are uncertain, preparations should be made to deal with a station blackout. The nature of those preparations, whether they be optimizing emergency procedures to use existing equipment, modifying this equipment to enhance capabilities, or adding new components or systems to cope with station blackout, must be made in light of plant-specific assessments and regulatory safety philosophies/requirements. Discussions on these matters are provided in chapter 4. General and specific conclusions and recommendations are provided in chapter 5. Appendix A provides a description of several case studies on station blackout and loss of off-site power. Abstracts of papers and presentations are provided in Appendix B with authors and affiliations identified to facilitate personal contact. The References and Bibliography contain a

  1. The 4 november 2006 blackout: an outage of 'technical' democracy?

    International Nuclear Information System (INIS)

    With its power plants and exportation of electricity to neighboring lands, France imagined that it was sheltered from blackouts. But in the autumn of 2006, five million French households were deprived of electricity due to an error by a German operator. What to think of this? The internationalization of the electricity market, though useful to consumers, should not mean deregulation or the relinquishment of rules and regulations to power companies. Supervision of the grid must be reinforced on behalf of all European users of electricity. (author)

  2. Reactor Cavity in Case of Station Blackout in RBMK-1500

    Directory of Open Access Journals (Sweden)

    Algirdas Kaliatka

    2007-01-01

    Full Text Available Ignalina NPP is equipped with channel-type boiling-water graphite-moderated reactor RBMK-1500. Results of the level-1 probabilistic safety assessment of the Ignalina NPP have shown that in topography of the risk, the transients with failure of long-term core cooling other than LOCA are the main contributors to the core damage frequency. The total loss of off-site power with a failure to start any diesel generator, that is station blackout, is the event which could lead to the loss of long-term core cooling. Such accident could lead to multiple ruptures of fuel channels with severe consequences and should be analyzed in order to estimate the timing of the key events and the possibilities for accident management. This paper presents the results of the analysis of station blackout at Ignalina NPP. Analysis was performed using thermal-hydraulic state-of-the-art RELAP5/MOD3.2 code. The response of reactor cooling system and the processes in the reactor cavity and its venting system in case of a few fuel-channel ruptures due to overheating were demonstrated. The possible measures for prevention of the development of this beyond design basis accident (BDBA to a severe accident are discussed.

  3. Thermohydraulic and Safety Analysis for CARR Under Station Blackout Accident

    International Nuclear Information System (INIS)

    A thermohydraulic and safety analysis code (TSACC) has been developed using Fortran 90 language to evaluate the transient thermohydraulic behaviors and safety characteristics of the China Advanced Research Reactor(CARR) under Station Blackout Accident(SBA). For the development of TSACC, a series of corresponding mathematical and physical models were considered. Point reactor neutron kinetics model was adopted for solving reactor power. All possible flow and heat transfer conditions under station blackout accident were considered and the optional models were supplied. The usual Finite Difference Method (FDM) was abandoned and a new model was adopted to evaluate the temperature field of core plate type fuel element. A new simple and convenient equation was proposed for the resolution of the transient behaviors of the main pump instead of the complicated four-quadrant model. Gear method and Adams method were adopted alternately for a better solution to the stiff differential equations describing the dynamic behaviors of the CARR. The computational result of TSACC showed the enough safety margin of CARR under SBA. For the purpose of Verification and Validation (V and V), the simulated results of TSACC were compared with those of Relap5/Mdo3. The V and V result indicated a good agreement between the results by the two codes. Because of the adoption of modular programming techniques, this analysis code is expected to be applied to other reactors by easily modifying the corresponding function modules. (authors)

  4. Safety analysis of Joyo in case of station blackout

    International Nuclear Information System (INIS)

    Due to the 2011 off the Pacific Coast of Tohoku Earthquake, and the accident of Fukushima Daiichi Nuclear Power Station on March 11, 2011, the importance of safety securement in case of power source function loss was reaffirmed. This paper describes the safety evaluation results of the reactor core and water cooling pond for storing spent fuel of 'Joyo' at the time of station blackout. Even when the forced circulation function is lost due to station blackout, the cooling system equipment is positioned with a height difference so as to remove the decay heat through natural circulation. In addition, the decay heat of the core can be removed by natural ventilation in the main cooler as the final heat removing device of the secondary cooling system. This fact has been demonstrated by the experiment of MK-I core and MK-II core, and it was also confirmed that even in MK-III, cooling by natural circulation is possible. As for the evaluation of the spent fuel cooling pond, even in the water cooling pond that is the nearest to reactor building block where the result is severest, water temperature rises up to about 70 deg C at a maximum, which gives an allowance of about 3.5 months until the cooling water is evaporated and fuel-filled can top is exposed. It is possible to replenish the cooling water during this period, so it was confirmed that the spent fuel can be cooled safely. (A.O.)

  5. Station blackout with reactor coolant pump seal leakage

    International Nuclear Information System (INIS)

    The U.S. Nuclear Regulatory Commission (NRC) amended its regulations in 10CFR50 with the addition of a new section, 50.63, open-quotes Loss of All Alternating Current Power.close quotes The objective of these requirements is to ensure that all nuclear plants have the capability to withstand a station blackout (SBO) and maintain adequate reactor core cooling and containment integrity for a specified period of time. The NRC also issued Regulatory Guide (RG) 1.155, open-quotes Station Blackout,close quotes to provide guidance for meeting the requirements of 10CFR50.63. Concurrent with RG-1.155, the Nuclear Utility Management and Resources Council (NUMARC) has developed NUMARC 87-00 to address SBO-coping duration and capabilities at light water reactors. Licensees are required to submit a topical report based on NUMARC 87-00 guidelines, to demonstrate compliance with the SBO rule. One of the key compliance criteria is the ability of the plant to maintain adequate reactor coolant system (RCS) inventory to ensure core cooling for the required coping duration, assuming a leak rate of 25 gal/min per reactor coolant pump (RCP) seal in addition to technical specification (TS) leak rate

  6. Integrated MELPROG/TRAC analyses of a PWR station blackout

    International Nuclear Information System (INIS)

    A complete, coupled, mechanistic analysis of the entire reactor coolant system during a station blackout accident (TMLB') has been completed using the MELPROG/TRAC code. The analysis includes the failure of the seal on all coolant pumps at 100 min into the accident; in all other respects the case is identical to a previous station blackout calculation. Both cases started at accident initiation and continued through boiloff of the water, failure of the control and fuel rods, oxidation of the zircaloy and the formation of U-Zr-O eutectics, failure of the vessel internal structures due to melting and loading, massive core disruption, and subsequent vessel failure. The two cases reached significantly different end conditions. The basic TMLB' resulted in a high pressure (15 MPa) vessel failure approximately 4 h after accident initiation. The addition of a 12.5-mm hole in each pump seal caused the water in the loop seal to clear and resulted in a significantly lower pressure (0.27 MPa) at vessel failure, which occurred almost 10 h after accident initiation. Therefore, high pressure melt ejection (HPME) and the potential for subsequent direct containment heating (DCH) were predicted not to occur in the TMLB' accident scenario with pump seal failure. (orig.)

  7. Emergency management and the August 14, 2003 blackout

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, B.L. [Wilfrid Laurier Univ., Waterloo, ON (Canada)

    2004-06-01

    This paper presents the results of a general population survey conducted after the blackout in August 2003 which left 50 million people in the northeast United States and southwestern Ontario without electricity for about 48 hours. The telephone survey questioned 1,203 people in order to determine the ability of households to deal with emergencies. The results offer a perspective of Ontario residents on the emergency management system in place during the blackout. They also reveal people's coping strategies and community patterns. Although millions of people were affected over a wide geographic range, the impacts were similar to those of a minor emergency, not a major disaster because no infrastructure was damaged and few, if any people were killed or hurt during the event. The results point to important emergency management concerns regarding the emergency preparedness of Ontario residents. It was concluded that Ontario residents are not well prepared for emergencies and disasters and that information regarding emergency preparedness should be provided through several sources and delivery methods. It was recommended that all levels of government should continue to upgrade their proactive emergency management. 2 tabs., 13 figs.

  8. Estimation of the inconvenience cost of a rolling blackout in the residential sector: The case of South Korea

    International Nuclear Information System (INIS)

    South Korea is experiencing a serious imbalance in electricity supply and demand, which caused a blackout in 2011. The Korean government has planned to perform a rolling blackout to prevent large-scale blackouts when the electricity supply reserve margin reaches less than 1 million kW. This study attempts to estimate the inconvenience cost of household customers from a rolling blackout by using survey data. To this end, we apply a contingent valuation method (CVM) to measure their willingness-to-pay (WTP) in order to avoid a rolling blackout, i.e. the suspension of electricity supply. In this study, we estimate the inconvenience costs stemming from both an unannounced and an announced rolling blackout. As a result, we find that the inconvenience cost of a sudden rolling blackout is estimated at 3900.67 KRW (3.56 USD) per month per household, while that of an announced rolling blackout stands at 3102.95 KRW (2.83 USD). This difference in costs shows that people place value in receiving prior notice of a blackout, and that inconvenience costs of between 166.0 billion KRW (151.6 million USD) and 174.3 billion KRW (159.2 million USD) per year can be reduced nationwide by giving households advance notice of a planned rolling blackout. - Highlights: • We estimate the inconvenience cost of a rolling blackout in households in South Korea. • We use a contingent valuation method to measure the WTP to avoid a rolling blackout. • People have more WTP to avoid an unannounced rolling blackout than an announced one. • We estimate the value of preannouncement of the blackout by the difference in WTPs

  9. Probabilistic evaluation of station blackout frequency for PFBR

    International Nuclear Information System (INIS)

    Electrical power systems play an important role in the normal running of the power plant as well as during shutdown conditions. In addition, the decay heat removal from the reactor when it is shut down and the need for monitoring the status of the reactor under all conditions necessitates that the electrical power supply systems are designed to a high degree of reliability. The frequency and duration of blackouts that can be tolerated impose requirements on the design of emergency heat removal systems as well as on the design of on-site electrical power systems. Taking these aspects into consideration, the reliability of electrical power systems of prototype fast breeder reactor (PFBR) project are examined

  10. Analysis of Peach Bottom station blackout with MELCOR

    International Nuclear Information System (INIS)

    A demonstration analysis of station blackout at Peach Bottom has been performed using MELCOR and the results have been compared with those from MARCON 2.1B and the Source Term Code Package (STCP). MELCOR predicts greater in-vessel hydrogen production, earlier melting and core collapse, but later debris discharge than MARCON 2.1B. The drywell fails at vessel breach in MELCOR, but failure is delayed about an hour in MARCON 2.1B. These differences are mainly due to the MELCOR models for candling during melting, in-core axial conduction, and continued oxidation and heat transfer from core debris following lower head dryout. Three sensitivity calculations have been performed with MELCOR to address uncertainties regarding modeling of the core-concrete interactions. The timing of events and the gas and radionuclide release rates are somewhat different in the base case and the three sensitivity cases, but the final conditions and total releases are similar

  11. Design Provisions for Station Blackout at Nuclear Power Plants

    International Nuclear Information System (INIS)

    A station blackout (SBO) is generally known as 'a plant condition with complete loss of all alternating current (AC) power from off-site sources, from the main generator and from standby AC power sources important to safety to the essential and nonessential switchgear buses. Direct current (DC) power supplies and un-interruptible AC power supplies may be available as long as batteries can supply the loads. Alternate AC power supplies are available'. A draft Safety Guide DS 430 'Design of Electrical Power Systems for Nuclear Power Plants' provides recommendations regarding the implementation of Specific Safety Requirements: Design: Requirement 68 for emergency power systems. The Safety Guide outlines several design measures which are possible as a means of increasing the capability of the electrical power systems to cope with a station blackout, without providing detailed implementation guidance. A committee of international experts and advisors from numerous countries is currently working on an IAEA Technical Document (TECDOC) whose objective is to provide a common international technical basis from which the various criteria for SBO events need to be established, to support operation under design basis and design extension conditions (DEC) at nuclear power plants, to document in a comprehensive manner, all relevant aspects of SBO events at NPPs, and to outline critical issues which reflect the lessons learned from the Fukushima Dai-ichi accident. This paper discusses the commonly encountered difficulties associated with establishing the SBO criteria, shares the best practices, and current strategies used in the design and implementation of SBO provisions and outline the structure of the IAEA's SBO TECDOC under development. (author)

  12. Integrated MELPROG/TRAC analyses of a PWR station blackout

    International Nuclear Information System (INIS)

    A complete, coupled, mechanistic analysis of the entire reactor coolant system during a station blackout (TMLB') has been completed using MELPROG/TRAC. The analysis includes the loss of all coolant pump seals at 100 minutes into the accident; in all other respects the case is identical to a previous station-blackout analysis. Both cases were initiated at the start of the accident and followed through boiloff of the water, failure of the control and fuel rods, oxidation of the Zircaloy and the formation of U-Zr-O eutectics, failure of the vessel internal structures due to melting and loading, massive core disruption and subsequent vessel failure. The two cases reached significantly different end conditions. The basic TMLB' resulted in a high pressure (15 MPa) vessel failure approximately 4 hours after accident initiation. The addition of a 12.5 mm hole in each pump seal resulted in a significantly lower pressure (0.27 MPa) at vessel failure, almost 10 hours after accident initiation. Therefore, high pressure melt ejection (HPME) and subsequent direct containment heating (DCH) were predicted not to occur in the TMLB' accident scenario with pump seal failure. This significant difference in end conditions demonstrates the need for a detailed, as well as mechanistic, treatment of the important physical processes within the complete reactor coolant system. The calculation shows the capabilities of MELPROG when coupled to TRAC, and that the resulting tool gives the user the potential to correctly predict, and therefore manage, an accident by determining the final results of possible operator interventions. 9 refs., 9 figs., 2 tabs

  13. Observing power blackouts from space - A disaster related study

    Science.gov (United States)

    Aubrecht, C.; Elvidge, C. D.; Ziskin, D.; Baugh, K. E.; Tuttle, B.; Erwin, E.; Kerle, N.

    2009-04-01

    In case of emergency disaster managers worldwide require immediate information on affected areas and estimations of the number of affected people. Natural disasters such as earthquakes, hurricanes, tornados, wind and ice storms often involve failures in the electrical power generation system and grid. Near real time identification of power blackouts gives a first impression of the area affected by the event (Elvidge et al. 2007), which can subsequently be linked to population estimations. Power blackouts disrupt societal activities and compound the difficulties associated with search and rescue, clean up, and the provision of food and other supplies following a disastrous event. Locations and spatial extents of power blackouts are key considerations in planning and execution of the primary disaster missions of emergency management organizations. To date only one satellite data source has been used successfully for the detection of power blackouts. Operated by NOAA's National Geophysical Data Center (NGDC) the U.S. Air Force Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) offers a unique capability to observe lights present at the Earth's surface at night. Including a pair of visible and thermal spectral bands and originally designed to detect moonlit clouds, this sensor enables mapping of lights from cities and towns, gas flares and offshore platforms, fires, and heavily lit fishing boats. The low light imaging of the OLS is accomplished using a photomultiplier tube (PMT) which intensifies the visible band signal at night. With 14 orbits collected per day and a 3.000 km swath width, each OLS is capable of collecting a complete set of images of the Earth every 24 hours. NGDC runs the long-term archive for OLS data with the digital version extending back to 1992. OLS data is received by NGDC in near real time (1-2 hours from acquisition) and subscription based services for the near real time data are provided for users all over the

  14. Sinister synergies : how competition for unregulated profit causes blackouts

    International Nuclear Information System (INIS)

    This white paper examined the effects of deregulation on electricity system reliability and demonstrated that the pursuit of unregulated profit has increased blackout risk. It was suggested that although deregulation works well in some areas, experts, studies and experience have shown that the deregulation of the electricity system has failed. The make-up of the electricity system was discussed, as well as the importance of the system to security, safety, health and economic well-being. It was suggested that higher costs and the need for greater profits have pushed deregulated power producers to cut costs drastically and to invest where high, short-term returns are more likely, rather than focusing on reasonable long-term returns with reasonable cost savings and reliability. In addition, the complexity of deregulated electricity markets has afforded participants many opportunities to manipulate and cut corners to increase profits. It was suggested that higher costs and the need for higher profits have combined with deregulated market conditions to provide motives and opportunities for a culture of bad behavior. This has cost consumers billions of dollars and resulted in increased blackout risk. It was noted that there have also been significant cut-backs in training, maintenance and rehabilitation, as well as in research. There has been a large increase in the complexity of deregulated systems because of increased numbers of participants, transactions and relationships, which has led to the introduction of new systems without appropriate testing, pilot projects, risk management, gradual implementation and backup procedures. It was concluded that an independent investigation should be carried out, and that a major study is needed to examine deregulated environments. 31 refs

  15. The treatment of station blackout in probabilistic risk assessment for a pressurized water reactor

    International Nuclear Information System (INIS)

    In this paper an integral method for calculating core melt frequency due to station blackout in a Westinghouse Pressurized Water Reactor is proposed. The major concerns considered in the calculation are the diesel generator failure time, the turbine-driven auxiliary feedwater system available time and the timely failure of reactor coolant pump seal. Sensitivity studies on the major issues related to the station blackout have also been investigated

  16. Extended Station Blackout Analysis for VVER-1000 MWe Reactor

    International Nuclear Information System (INIS)

    Post Fukushima, the plant behaviour for an extended station black-out (ESBO) scenario with only passive system availability for about 7 days has become imperative. Thermal hydraulic analysis of ESBO with the availability of passive heat removal system (PHRS), passive first stage and second stage hydro accumulators were carried out to demonstrate the design capabilities. Two different cases having primary leak rates of 2.2 tons/hr and 6.6 tons/hr were analyzed to study sustenance of natural circulation. For the study, out of 4 PHRS trains, one PHRS train was assumed to be in failure mode. The objective here is to predict the core cooling capability for a period of 7 days under ESBO conditions with the available water inventories from first and second stage hydroaccumulators only. Over simplified energy balance studies cannot ascertain sustenance of natural circulation in the primary system, steam generators (SGs) and PHRS. The analysis was carried out by using system thermal hydraulic safety code RELAP5/SCDAP/MOD 3.4. It is inferred that the inventory in the first stage accumulators and second stage accumulators compensate the leak and decay heat is removed effectively with the help of passive heat removal systems. It is also observed that even after 7 days of ESBO a large inventory is still available in the second stage accumulators and the primary system remains subcooled. (author)

  17. Cooling methods of station blackout scenario for LWR plants

    International Nuclear Information System (INIS)

    The objective of this study is to analyze the cooling method of station blackout scenario for both the BWR and PWR plants by RELAP5 code and to check the validity of the cooling method proposed by the utilities. In the BWR plant cooling scenario, the Reactor Core Isolation Cooling System (RCIC), which is operated with high pressure steam from the reactor, injects cooling water into the reactor to keep the core water level. The steam generated in the core is released into the suppression pool at containment vessel to condense. To restrict the containment vessel pressure rising, the ventilation from the wet-well is operated. The scenario is analyzed by RELAP5 code. In the PWR plant scenario, the primary pressure is decreased by the turbine-driven auxiliary feed water system operated with secondary side steam of the steam generators (SGs). And the core cooling is kept by the natural circulation flow at the primary loop. From the RELAP5 code analysis, it was shown that the primary system cooling was practicable by using the turbine-driven auxiliary feed water system. (author)

  18. Impact assessment of the 1977 New York City blackout. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Corwin, J. L.; Miles, W. T.

    1978-07-01

    This study was commissioned by the Division of Electric Energy Systems (EES), Department of Energy (DOE) shortly after the July 13, 1977 New York City Blackout. The objectives were two-fold: to assess the availability and collect, where practical, data pertaining to a wide variety of impacts occurring as a result of the blackout; and to broadly define a framework to assess the value of electric power reliability from consideration of the blackout and its effects on individuals, businesses, and institutions. The impacts were complex and included both economic and social costs. In order to systematically classify the most significant of these impacts and provide guidance for data collection, impact classification schemes were developed. Major economic impact categories examined are business; government; utilities (Consolidated Edison); insurance industry; public health services; and other public services. Impacts were classified as either direct or indirect depending upon whether the impact was due to a cessation of electricity or a response to that cessation. The principal economic costs of the blackout are shown. Social impacts, i.e., the changes in social activities and adaptations to these changes were particularly significant in New York due to its unique demographic and geographic characteristics. The looting and arson that accompanied the blackout set aside the NYC experience from other similar power failures. (MCW)

  19. Investigation of a Station Blackout Scenario with the ATLAS Test

    International Nuclear Information System (INIS)

    KAERI (Korea Atomic Energy Research Institute) has been operating an integral effect test facility, ATLAS (Advanced Thermal-Hydraulic Test Loop for Accident Simulation), for accident simulations pertaining to the OPR1000 (Optimized Power Reactor, 1000MWe) and the APR1400 (Advanced Power Reactor, 1400MWe) which are in operation and under construction in Korea, respectively. After the Fukushima accidents due to the combination of an earthquake followed by a tsunami in east Japan on March 11, 2011, the concept of boundary between the design basis and beyond-design basis accidents became obscure. One scenario is the station blackout (SBO), which is defined as 'the loss of all alternating current (AC) power in a nuclear power plant' by the USNRC 10CFR50 Section 50.63, which has adopted a new safety regulation for the SBO in June of 1988. In any case the SBO that occurred in Fukushima seemed to go beyond the definition of the current SBO scenario. In the mean time, numerous researches has been conducted on the safety concern of the SBO for existing and advanced nuclear power plants worldwide. From the internal review of an SBO scenario, it was concluded that the understanding of the thermo-hydraulic phenomena occurred within the reactor coolant system is a prerequisite although seemed to be quite a simple sequence of events. This was the motivation of an SBO test using the ATLAS facility. For the understanding of the physical phenomena within the primary system, an SBO was assumed with simple intial and boundary conditions, e.g. start of an SBO at time zero, no diesel and AC powers, no auxiliary feedwater pumps (motor-driven and turbine driven) etc. In this paper, overview of the SBO test results was described including a result of analytical calculations simulating the SBO test using the MARS code

  20. Evaluation of MELCOR improvements: Peach Bottom station blackout analyses

    International Nuclear Information System (INIS)

    Long-term station blackout analyses in Peach Bottom were first carried out using MELCOR 1.8BC, and later with 1.8DN, as part of an overall program between the US Nuclear Regulatory Commission (NRC) and Brookhaven National Laboratory (BNL), to provide independent assessment of MELCOR as a severe accident/source term analysis tool. In addition to the reference MELCOR calculation, several sensitivity calculations were also performed to explore the impact of varying user-input modeling and timestep control parameters on the accident progression and radionuclide releases to the environment calculated by MELCOR. An area of concern that emerged from these studies was the impact of the selection of maximum allowable timestep (Δtmax) on the calculational behavior of MELCOR, where the results showed significant differences in timing of key events, and a lack of convergence of the solution with reduction of Δtmax. These findings were reported to the NRC, SNL, and the MELCOR Peer Review Committee. As a consequence, a significant effort was undertaken to eliminate or mitigate these sensitivities. The latest released version of MELCOR, Version 1.8.2, released in April 1993, contains several new or improved models, and has corrections to mitigate numerical sensitivities. This paper presents the results of updating the earlier sensitivity studies on maximum timestep, to more properly represent the abilities of the improved MELCOR version 1.8.2. Results are presenter in terms of timing of key events, thermal-hydraulic response of the system, and environmental release of radionuclides. The impact of some of the newer models, such as falling debris quench model, and ORNL's new BH model, is also evaluated

  1. Benchmarking Simulation of Long Term Station Blackout Events

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Kyum; Lee, John C. [POSTECH, Pohang (Korea, Republic of); Fynan, Douglas A.; Lee, John C. [Univ. of Michigan, Ann Arbor (United States)

    2013-05-15

    The importance of passive cooling systems has emerged since the SBO events. Turbine-driven auxiliary feedwater (TD-AFW) system is the only passive cooling system for steam generators (SGs) in current PWRs. During SBO events, all alternating current (AC) and direct current (DC) are interrupted and then the water levels of steam generators become high. In this case, turbine blades could be degraded and cannot cool down the SGs anymore. To prevent this kind of degradations, improved TD-AFW system should be installed for current PWRs, especially OPR 1000 plants. A long-term station blackout (LTSBO) scenario based on the improved TD-AFW system has been benchmarked as a reference input file. The following task is a safety analysis in order to find some important parameters causing the peak cladding temperature (PCT) to vary. This task has been initiated with the benchmarked input deck applying to the State-of-the-Art Reactor Consequence Analyses (SOARCA) Report. The point of the improved TD-AFW is to control the water level of the SG by using the auxiliary battery charged by a generator connected with the auxiliary turbine. However, this battery also could be disconnected from the generator. To analyze the uncertainties of the failure of the auxiliary battery, the simulation for the time-dependent failure of the TD-AFW has been performed. In addition to the cases simulated in the paper, some valves (e. g., pressurizer safety valve), available during SBO events in the paper, could be important parameters to assess uncertainties in PCTs estimated. The results for these parameters will be included in a future study in addition to the results for the leakage of the RCP seals. After the simulation of several transient cases, alternating conditional expectation (ACE) algorithm will be used to derive functional relationships between the PCT and several system parameters.

  2. Integrated TRAC/MELPROG analyses of a PWR station blackout

    International Nuclear Information System (INIS)

    The first complete, coupled, and largely mechanistic analysis of the entire reactor-coolant system during a station blackout (TMLB') core-meltdown accident has been made with MELPROG/TRAC. The calculation was initiated at the start of the transient and ended with a late recovery of cooling. Additional cooling provided by water from the primary system delayed events relative to a standalone MELPROG calculation. Natural circulation within the vessel was established and primary-relief-valve action did little to disturb this flow. In addition, it was calculated directly that the hot leg reached a failure temperature long before vessel failure. Beyond relocation of the core, we have calculated the boiloff of the water in the lower head and have estimated the time of vessel failure to be at about 14,700 s into the transient. For ''nominal'' corium-water heat transfer, the boiloff process (steam-production rate) is slow enough that the relief valves prevent pressurization beyond 17.5 MPa. Parametric cases with increased corium-water heat transfer resulted in steaming rates beyond the capability of the relief valves, leading to pressures in excess of 19.2 MPa. Natural convection flow around the loop, if started by removing the water in the loop seal, was blocked by a relatively less-dense hydrogen/steam mixture that flowed to the top of the steam generator. Emergency core-cooling system activation late in the transient (after core slump) resulted in rapid cooling of the periphery of the debris region but slower cooling in the interior regions because of poor water penetration

  3. 47 CFR 76.120 - Network non-duplication protection, syndicated exclusivity and sports blackout rules for...

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Network non-duplication protection, syndicated... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.120 Network non-duplication protection, syndicated exclusivity and sports blackout rules...

  4. An analysis of station blackout sequences for the severe accident analysis database (II)

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soo Yong; Kim, Dong Ha

    2006-08-15

    This report contains analysis methodologies and calculation results of station blackout sequences for the severe accident analysis database system. The Korean standard nuclear power plant has been selected as a reference plant. Based on the probabilistic safety analysis of the corresponding plant. Eight accident scenarios, which was predicted to have more than 10{sup -10}/ry occurrence frequency have been analyzed as base cases for the station blackout sequence database. Furthermore, the sensitivity studies for operational plant systems and for phenomenological models of the analysis computer code have been performed. The functions of the severe accident analysis database system will be to make a diagnosis of the accident by some input information from the plant symptoms, to search a corresponding scenario, and finally to provide the user phenomenological information based on the pre-analyzed results. The MAAP 4.06 calculation results of station blackout sequence in this report will be utilized as input data of the severe accident analysis database system.

  5. An analysis of station blackout sequences for the severe accident analysis database (II)

    International Nuclear Information System (INIS)

    This report contains analysis methodologies and calculation results of station blackout sequences for the severe accident analysis database system. The Korean standard nuclear power plant has been selected as a reference plant. Based on the probabilistic safety analysis of the corresponding plant. Eight accident scenarios, which was predicted to have more than 10-10/ry occurrence frequency have been analyzed as base cases for the station blackout sequence database. Furthermore, the sensitivity studies for operational plant systems and for phenomenological models of the analysis computer code have been performed. The functions of the severe accident analysis database system will be to make a diagnosis of the accident by some input information from the plant symptoms, to search a corresponding scenario, and finally to provide the user phenomenological information based on the pre-analyzed results. The MAAP 4.06 calculation results of station blackout sequence in this report will be utilized as input data of the severe accident analysis database system

  6. Learning from the blackouts. Transmission system security in competitive electricity markets

    Energy Technology Data Exchange (ETDEWEB)

    none

    2005-07-01

    Electricity market reform has fundamentally changed the environment for maintaining reliable and secure power supplies. Growing inter-regional trade has placed new demands on transmission systems, creating a more integrated and dynamic network environment with new real-time challenges for reliable and secure transmission system operation. Despite these fundamental changes, system operating rules and practices remain largely unchanged. The major blackouts of 2003 and 2004 raised searching questions about the appropriateness of these arrangements. Management of system security needs to be transformed to maintain reliable electricity services in this more dynamic operating environment. These challenges raise fundamental issues for policymakers. This publication presents case studies drawn from recent large-scale blackouts in Europe, North America, and Australia. It concludes that a comprehensive, integrated policy response is required to avoid preventable large-scale blackouts in the future.

  7. Implications of Extension of Station Blackout Cooping Capability on Nuclear Power Plant Safety

    International Nuclear Information System (INIS)

    The safety of the nuclear power plant depends on the availability of the continuous and reliable sources of electrical energy during all modes of operation of the plant. The station blackout corresponds to a total loss of all alternate current (AC) power as a result of complete failure of both offsite and on-site AC power sources. The electricity for the essential systems during station blackout is provided from the batteries installed in the nuclear power plant. The results of the probabilistic safety assessment show that station blackout is one of the main and frequently the dominant contributor to the core damage frequency. Results of the analysis of the implications of the strengthening of the SBO mitigation capability on safety of the NPP will be presented. The assessment is done with state-of-art deterministic and probabilistic methods and tolls with application on reference models of nuclear power plants. The safety analysis is done on reference model of the nuclear power plant. Obtained results show large decrease of the core damage frequency with strengthening of the station blackout mitigation capability. The time extension of blackout coping capability results in the delay of the core heat up for at least the extension time interval. Availability and operation of the steam driven auxiliary feedwater system maintains core integrity up to 72 h after the successful shutdown, even in the presence of the reactor coolant pumps seal leakage. The largest weighted decrease of the core damage frequency considering the costs for the modification is obtained for the modification resulting in extension of the station blackout coping capability. The importance of the common cause failures of the emergency diesel generators for the obtained decrease of the core damage frequency and overall safety of the plant is identified in the obtained results. (authors)

  8. Public Health Concerns Associated with the New York City Blackout of 1977.

    Science.gov (United States)

    Imperato, Pascal James

    2016-08-01

    The 1977 New York City blackout began at 9:36 p.m. on 13 July and lasted some 25 h until 10:39 p.m. on 14 July. The New York City Department of Health rapidly set up a Blackout Contingency Plan, established priorities, and mobilized its staff to address remedial interventions. Top priorities included water supplies, sewage disposal, perishable food supplies, hospital and emergency room services, solid waste disposal, beach contamination with untreated sewage , and assisting those on electrically powered home life support systems. The 1977 blackout occurred during an extended heat wave. An analysis of total deaths and deaths due to pulmonary and cardiovascular/renal diseases by day correlated with temperatures. However, there was no direct correlation with the blackout itself, in part perhaps because of the confounding influence of high temperatures. The increase of deaths on very hot days outside of the blackout period lends strong support to the relationship between increased deaths and high ambient temperatures. The 1977 New York City blackout was distinguished from those of 1965 and 2003 by violence, arson, and looting that occurred in several areas. These acts resulted in 204 civilian injuries, 436 police injuries, 80 firefighter injuries, and 1037 fires. The violence, arson, and looting caused extensive long-term physical and functional damage to certain areas of two boroughs of the city, Brooklyn and the Bronx. Although the New York City Department of Health had not previously established a disaster preparedness plan, its professionals quickly rose to the occasion because they were able to draw upon vast public health practice experience and ingenuity. PMID:27220853

  9. Modern approach to power supply of systems important to NPP safety under in-house blackout

    International Nuclear Information System (INIS)

    The paper considers preconditions to revise a strategy of Ukrainian NPP in-house power supply and new approaches to arrangement of power supply of safety system loads from on-site power sources and mobile diesel generators. In addition, the paper shows a new scheme of power supply to safety system loads in case of blackout.

  10. Acute Alcohol Effects on Contextual Memory BOLD Response: Differences Based on Fragmentary Blackout History

    Science.gov (United States)

    Wetherill, Reagan R.; Schnyer, David M.; Fromme, Kim

    2011-01-01

    Background Contextual memory, or memory for source details, is an important aspect of episodic memory and has been implicated in alcohol-induced fragmentary blackouts (FB). Little is known, however, about how neural functioning during contextual memory processes may differ between individuals with and without a history of fragmentary blackouts. This study examined whether neural activation during a contextual memory task differed by history of fragmentary blackout and acute alcohol consumption. Methods Twenty-four matched individuals with (FB+; n = 12) and without (FB−; n = 12) a history of FBs were recruited from a longitudinal study of alcohol use and behavioral risks and completed a laboratory beverage challenge followed by two functional magnetic resonance imaging (fMRI) sessions under no alcohol and alcohol [breath alcohol concentration (BrAC) = 0.08%] conditions. Task performance and brain hemodynamic activity during a block design contextual memory task were examined across 48 fMRI sessions. Results Groups demonstrated no differences in performance on the contextual memory task, yet exhibited different brain response patterns after alcohol intoxication. A significant FB group by beverage interaction emerged in bilateral dorsolateral prefrontal cortex and posterior parietal cortex with FB− individuals showing greater BOLD response after alcohol exposure (p blackouts. PMID:22420742

  11. Station Blackout Initiated Event Chronology in LWR/HWR NPP

    International Nuclear Information System (INIS)

    Since the crisis at Fukushima nuclear power plants, a severe accident progression has been recognized as a very important area for an accident management and emergency planning. The purpose of this study is to investigate the comparative characteristics of a severe accident progression among the typical pressurized water reactor (PWR), boiling water reactor (BWR) and pressurized heavy water reactor (PHWR). The OPR 1000-like (ABB-CE type PWR), Peach Bottom-like (BWR/4 RCS with a MARK I Containment), and Wolsong1-like (CANDU6 type) plants are selected as reference plants of typical 1000 MWe PWR, 1140MWe BWR, and 600 MWe PHWR, respectively. The design parameters of these plants are quite different. Some of the major different design features of CANDU6 plant from other light water reactors, in terms of a severe accident, are that the plant adopts a duel primary heat transport system and has an additional amount of cooling water in the calandria vessel (calandria tank, CT) and calandria vault (CV). Another feature is that the CT is always submerged in water because the CV is flooded during normal operation. The containment (reactor building, R/B) failure pressure of the CANDU6 plant is considerably lower than that of the typical PWR or BWR4/MARK-I. The containment vessel free volume of MARK-I is much smaller than that of the PWR or CANDU6 plant. Since there is no steam generator (SG) or passive cooling system, the amount of cooling water inventory in BWR4 is relatively less than other plants. Meanwhile the minimum available time of battery power against station blackout (SBO) accident is different among plant types: six hours for BWR4 and four hours for 1000MWe PWR. Therefore, plant responses against the severe core damage scenarios like Fukushima accident are expected to be much different. By identifying plant response signatures, the appropriate correction actions can be developed as part of severe accident management. A SBO scenario, where all off-site power is lost

  12. Station Blackout Initiated Event Chronology in LWR/HWR NPP

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soo Yong; Ahn, Kwang Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    Since the crisis at Fukushima nuclear power plants, a severe accident progression has been recognized as a very important area for an accident management and emergency planning. The purpose of this study is to investigate the comparative characteristics of a severe accident progression among the typical pressurized water reactor (PWR), boiling water reactor (BWR) and pressurized heavy water reactor (PHWR). The OPR 1000-like (ABB-CE type PWR), Peach Bottom-like (BWR/4 RCS with a MARK I Containment), and Wolsong1-like (CANDU6 type) plants are selected as reference plants of typical 1000 MWe PWR, 1140MWe BWR, and 600 MWe PHWR, respectively. The design parameters of these plants are quite different. Some of the major different design features of CANDU6 plant from other light water reactors, in terms of a severe accident, are that the plant adopts a duel primary heat transport system and has an additional amount of cooling water in the calandria vessel (calandria tank, CT) and calandria vault (CV). Another feature is that the CT is always submerged in water because the CV is flooded during normal operation. The containment (reactor building, R/B) failure pressure of the CANDU6 plant is considerably lower than that of the typical PWR or BWR4/MARK-I. The containment vessel free volume of MARK-I is much smaller than that of the PWR or CANDU6 plant. Since there is no steam generator (SG) or passive cooling system, the amount of cooling water inventory in BWR4 is relatively less than other plants. Meanwhile the minimum available time of battery power against station blackout (SBO) accident is different among plant types: six hours for BWR4 and four hours for 1000MWe PWR. Therefore, plant responses against the severe core damage scenarios like Fukushima accident are expected to be much different. By identifying plant response signatures, the appropriate correction actions can be developed as part of severe accident management. A SBO scenario, where all off-site power is lost

  13. The reactor core behaviour in case of small break loss of coolant accident combined with total blackout

    International Nuclear Information System (INIS)

    After the Fukushima accident an extreme event beyond design basis is shown to be possible. The detailed analyses of an extended station blackout, where all the onsite and offsite power is failed, became very important. A large number of analyses were done in all countries operating nuclear reactors. An analysis of small break loss of coolant accident combined with total blackout is presented in this work. The operator actions in this case are very important in order to extend the time before irreversible damage to the core is done. The analysis is performed using RELAP5/Mod 3.3 for VVER‑1000 type reactor. The main conclusions are that the current emergency operating procedures are adequate to manage station blackout with small break loss of coolant accident (SBLOCA) sequence. Key words: LOCA, Safety Analyses Report, Blackout, Severe Accident

  14. On power system blackout modeling and analysis based on self-organized criticality

    Institute of Scientific and Technical Information of China (English)

    MEI ShengWei; XUE AnCheng; ZHANG XueMin

    2008-01-01

    This paper makes a comprehensive survey on power system blackout modeling and analysis based on SOC (self-organized criticality). Firstly, a generalized SOC theory from the viewpoint of cybernetics is introduced. Then the evolution model of power system and its relative mathematical description, which serves as a concrete example of the proposed generalized SOC, are given. Secondly, five blackout models capturing various critical properties of power systems in different time-scales are listed. Finally, this paper analyzes SOC in power systems, such as, the revelation of criticalities of proposed models in both micro-scale and macro-scale which can be used to assess the security of power system, and cascading failures process.

  15. On power system blackout modeling and analysis based on self-organized criticality

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper makes a comprehensive survey on power system blackout modeling and analysis based on SOC (self-organized criticality). Firstly,a generalized SOC theory from the viewpoint of cybernetics is introduced. Then the evolution model of power system and its relative mathematical description,which serves as a concrete example of the proposed generalized SOC,are given. Secondly,five blackout models capturing various critical properties of power systems in different time-scales are listed. Finally,this paper analyzes SOC in power systems,such as,the revelation of criticalities of proposed models in both micro-scale and macro-scale which can be used to assess the security of power system,and cas-cading failures process.

  16. Case study on the use of PSA methods: Station blackout risk at Millstone Unit 3

    International Nuclear Information System (INIS)

    In Westinghouse pressurized water reactors, severe accidents sequences resulting from station blackout have been recognized to be significant contributors to risk of core damage and public consequences. To properly quantify the risk of station blackout it is necessary to consider all possible types of core damage scenarios. Having obtained an accurate representation of the types of core damage scenarios involved specific areas of vulnerability can be pinpointed for further improvement. In performing this analysis it was decided to use time dependent probabilistic safety assessment method to provide a more realistic treatment of time dependent failure and recovery. Overview of the analysis, calculation procedures and methods, interpretation of the results are discussed. Peer review process is described. 13 refs, 19 figs

  17. Probabilistic assessment of the Juragua NPP response under Station Blackout conditions

    International Nuclear Information System (INIS)

    Assessment of the NPP response under SBO (station Blackout) conditions is a current safety issue of special interest, In the case of Juragua NPP, the safety assessment related to this topic is very important, taking into account the peculiarities of the Cuban Electro energetic System: small and long island, without possibilities of conexion beyond its borders and under the incidence of tropical phenomena In this papers a preliminary evaluation is presented of the potential incidence of Station Blackout conditions for Juragua NPP. the importance of this sort of events for the safety of the plant is evaluated, the factors which condition it are identified and measures for its prevention or recovering the normal situation if such an event takes place are proposed

  18. The AP1000{sup R} nuclear power plant innovative features for extended station blackout mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Vereb, F.; Winters, J.; Schulz, T.; Cummins, E.; Oriani, L. [Westinghouse Electric Company LLC, 1000 Westinghouse Drive, Cranberry Township, PA 16066 (United States)

    2012-07-01

    Station Blackout (SBO) is defined as 'a condition wherein a nuclear power plant sustains a loss of all offsite electric power system concurrent with turbine trip and unavailability of all onsite emergency alternating current (AC) power system. Station blackout does not include the loss of available AC power to buses fed by station batteries through inverters or by alternate AC sources as defined in this section, nor does it assume a concurrent single failure or design basis accident...' in accordance with Reference 1. In this paper, the innovative features of the AP1000 plant design are described with their operation in the scenario of an extended station blackout event. General operation of the passive safety systems are described as well as the unique features which allow the AP1000 plant to cope for at least 7 days during station blackout. Points of emphasis will include: - Passive safety system operation during SBO - 'Fail-safe' nature of key passive safety system valves; automatically places the valve in a conservatively safe alignment even in case of multiple failures in all power supply systems, including normal AC and battery backup - Passive Spent Fuel Pool cooling and makeup water supply during SBO - Robustness of AP1000 plant due to the location of key systems, structures and components required for Safe Shutdown - Diverse means of supplying makeup water to the Passive Containment Cooling System (PCS) and the Spent Fuel Pool (SFP) through use of an engineered, safety-related piping interface and portable equipment, as well as with permanently installed onsite ancillary equipment. (authors)

  19. Development of an emergency procedure guideline for station blackout for the Combustion Engineering owners group

    International Nuclear Information System (INIS)

    A strategy for operator response to station blackout events has been developed. This strategy optimizes the control of RCS heat removal rate by indexing it to the RCS leak rate as indicated by changes in the RCS subcooled margin. Optimum reactor operator control of steam and feed flow rates is based on maintaining RCS subcooling in the range of 11.1 - 27.8 degrees C (20-50 degrees F)

  20. Effect of steam-exhaust operation of secondary coolant circuit on ship reactor blackout accident

    International Nuclear Information System (INIS)

    Highlights: • The ship reactor blackout accident (SRBA) is simulated by the RELAP5/MOD3.2 code. • The mitigation effect of steam-exhaust-operation (SEO) on the SRBA is analyzed. • Reasonable SEO scheme can obviously mitigate the accident for several hours. • The SEO scheme without feed water device can hardly mitigate the SRBA. • The failure of intercurrent steam flux control valve will result in the decrease of mitigation time. - Abstract: The ship reactor blackout accident can potentially lead to the severe accident and the radioactive fission product release. In the absence of auxiliary electrical source, the effective mitigation of the accident aftereffect is very important. As the exclusive heat trap in the reactor coolant system, the steam-exhaust operation (SEO) in the secondary coolant circuit (SCC) plays an important role in the accident mitigation. In view of the character of ship nuclear power plant (NPP), the ship reactor blackout accident (SRBA) under the typical operating conditions is simulated by the RELAP5/MOD3.2 code, and the mitigation of SEO on the accident is analyzed. It is found that (1) reasonable SEO can obviously mitigate the accident for several hours, the SEO with 1% rated steam flux of secondary coolant circuit provides about 7 h for the mitigation of accident, (2) a less steam flux of SCC during the SEO means a slower pressure drop of steam generation (SG) and a more time we can mitigate the accident, there are 1.5 h between the SEO with 1% rated steam flux and that with 3% rated steam flux, (3) the SEO without the feed water device can hardly mitigate the accident, and (4) during the blackout accident, the SEO with intercurrent steam flux control valve failure will result in the decrease of mitigation time because of the quick decrease of SG pressure, but the mitigation effect is also obvious

  1. Prediction Performance of Blackout and Plasma Attenuation in Atmospheric Reentry Demonstrator Mission

    OpenAIRE

    Takahashi, Yusuke; Yamada, Kazuhiko; Abe, Takashi

    2014-01-01

    A numerical simulation model that combines the plasma ows and electromagnetic waves around a reentry vehicle during atmospheric reentry was developed to evaluate the radio frequency blackout and plasma attenuation. The physical properties of the plasma ow in the shock layer and wake region were obtained using a computational uid dynamics technique. The electromagnetic waves were expressed using a frequency- dependent nite-difference time-domain method with the plasma ...

  2. Analysis of Radio Frequency Blackout for a Blunt-Body Capsule in Atmospheric Reentry Missions

    OpenAIRE

    Yusuke Takahashi; Reo Nakasato; Nobuyuki Oshima

    2016-01-01

    A numerical analysis of electromagnetic waves around the atmospheric reentry demonstrator (ARD) of the European Space Agency (ESA) in an atmospheric reentry mission was conducted. During the ARD mission, which involves a 70% scaled-down configuration capsule of the Apollo command module, radio frequency blackout and strong plasma attenuation of radio waves in communications with data relay satellites and air planes were observed. The electromagnetic interference was caused by highly dense pla...

  3. Modeling Advanced Neutron Source reactor station blackout accident using RELAP5

    International Nuclear Information System (INIS)

    The Advanced Neutron Source (ANS) system model using RELAP5 has been developed to perform loss-of-coolant accident (LOCA) and non-LOCA transients as safety-related input for early design considerations. The transients studies include LOCA, station blackout, and reactivity insertion accidents. The small-, medium-, and large-break LOCA results were presented and documented. This paper will focus on the station blackout scenario. The station blackout analyses have concentrated on thermal-hydraulic system response with and without accumulators. Five transient calculations were performed to characterize system performance using various numbers and sizes of accumulators at several key sites. The main findings will be discussed with recommendations for conceptual design considerations. ANS is a state-of-the-art research reactor to be built and operated at high heat flux, high mass flux, and high coolant subcooling. To accommodate these features, three ANS-specific changes were made in the RELAP5 code by adding: the Petukhov heat transfer correlation for single-phase forced convection in the thin coolant channel; the Gambill additive method with the Weatherhead wall superheat for the critical heat flux; and the Griffith drift flux model for the interfacial drag in the slug flow regime. 7 refs., 6 figs., 1 tab

  4. Analysis of hot leg natural circulation under station blackout severe accident

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Under severe accidents, natural circulation flows are important to influence the accident progression and result in a pressurized water reactor (PWR). In a station blackout accident with no recovery of steam generator (SG) auxiliary feedwater (TMLB' severe accident scenario), the hot leg countercurrent natural circulation flow is analyzed by using a severe-accident code, to better understand its potential impacts on the creep-rupture timing among the surge line, the hot leg, and SG tubes. The results show that the natural circulation may delay the failure time of the hot leg.The recirculation ratio and the hot mixing factor are also calculated and discussed.

  5. Muerte por sumersión debida a shallow water blackout

    OpenAIRE

    J.L. Palomo Rando; V. Ramos Medina; M.A. Calvo López; I.M. Santos Amaya

    2014-01-01

    El llamado shallow water blackout, o síncope de las aguas superficiales, es un accidente que pueden sufrir los buceadores y llevarles a la muerte por sumersión. La natación sumergido (buceando) precedida de hiperventilación crea una situación en la que el sujeto puede sufrir hipoxia antes de que la concentración en sangre arterial de dióxido de carbono alcance el nivel que le obligue a salir a la superficie a respirar. En esta situación, el sujeto inconsciente puede respirar bajo el agua y mo...

  6. Comparison of the MAAP4 code with the station blackout simulation in the IIST facility

    International Nuclear Information System (INIS)

    Full text of publication follows: The Modular Accident Analysis Program (MAAP) is an integral system model to assess challenges to the reactor core, Reactor Coolant System (RCS) and containment for accident conditions. MAAP4 is the current version used by the MAAP Users Group to assess the responses to a spectrum of accident conditions. Benchmarking of the MAAP code with integral system experiments has been a continuing effort by MAAP developers and users. Several of these have been configured into dynamic benchmarks and are included in Volume III (Benchmarking) of the MAAP4 Users Manual (EPRI, 2004). One such integral experiment is the INER integral system test (IIST) constructed at the Institute of Nuclear Energy Research in Taiwan. This experimental facility is a reduced height, reduced pressure representation of a 3-loop PWR and has been used to examine several different types of accident sequences. One of these is a station blackout simulation with loss of auxiliary feedwater at the time that the transient is initiated. This is an important integral experiment to be compared with the MAAP4 code models. A parameter file (those values representing the system design and boundary experimental conditions) has been developed for the IIST facility and an input deck has been configured to represent a station blackout sequence with instantaneous loss of auxiliary feedwater. Of importance in this benchmark is (a) the rate at which the secondary side inventory is depleted, (b) the depletion of water within the reactor pressure vessel and (c) the time at which the top of the reactor core is uncovered. Comparisons have been made with these three different intervals and there is good agreement between the timing of these events for the MAAP4 benchmark. This is important since this reference sequence represents a set of boundary conditions that is continually with subsequent analyses being perturbations on this type of accident sequence. The good agreement between MAAP4 and

  7. Real-time stability in power systems techniques for early detection of the risk of blackout

    CERN Document Server

    Savulescu, Savu

    2014-01-01

    This pioneering volume has been updated and enriched to reflect the state-of-the-art in blackout prediction and prevention. It documents and explains background and algorithmic aspects of the most successful steady-state, transient and voltage stability solutions available today in real-time. It also describes new, cutting-edge stability applications of synchrophasor technology, and captures industry acceptance of metrics and visualization tools that quantify and monitor the distance to instability. Expert contributors review a broad spectrum of additionally available techniques, such as traje

  8. Shudder on large scale of blackout in Tokyo and position of its responsibility

    International Nuclear Information System (INIS)

    By losing reliability of the Japanese on nuclear energy begun by incorrect descriptions on self-inspection data at the Tokyo Electric Power Co., Ltd. (TEPCO), all of nuclear power plants in Japan are under inspection. On such conditions, TEPCO will reach to an abnormal situation where all of seventeen sets of nuclear power plants will stop their operation on next April, unless the stopped plants can be obtained agreement of their local residents on re-starting their operations. And, as the 'maintenance standard' on nuclear power generation facilities with any imperfection on their legal systems was established by new legislative measures, its concrete measures will be summarized on October. Among such period, preparatory ratio of power supply of TEPCO will be about 4% on February and 0% on March. If the Metropolitan Tokyo is suffered by a large scale of blackout, Japan would have to be very panic. By what reason no Japanese has any tension feeling on the blackout? Under elucidation on actual facts on absence of its responsible person, here were searched on responses to nuclear energy problem and measures to evade irretrievable risk. (G.K.)

  9. Analysis of Radio Frequency Blackout for a Blunt-Body Capsule in Atmospheric Reentry Missions

    Directory of Open Access Journals (Sweden)

    Yusuke Takahashi

    2016-01-01

    Full Text Available A numerical analysis of electromagnetic waves around the atmospheric reentry demonstrator (ARD of the European Space Agency (ESA in an atmospheric reentry mission was conducted. During the ARD mission, which involves a 70% scaled-down configuration capsule of the Apollo command module, radio frequency blackout and strong plasma attenuation of radio waves in communications with data relay satellites and air planes were observed. The electromagnetic interference was caused by highly dense plasma derived from a strong shock wave generated in front of the capsule because of orbital speed during reentry. In this study, the physical properties of the plasma flow in the shock layer and wake region of the ESA ARD were obtained using a computational fluid dynamics technique. Then, electromagnetic waves were expressed using a frequency-dependent finite-difference time-domain method using the plasma properties. The analysis model was validated based on experimental flight data. A comparison of the measured and predicted results showed good agreement. The distribution of charged particles around the ESA ARD and the complicated behavior of electromagnetic waves, with attenuation and reflection, are clarified in detail. It is suggested that the analysis model could be an effective tool for investigating radio frequency blackout and plasma attenuation in radio wave communication.

  10. Interpreting transnational infrastructure vulnerability: European blackout and the historical dynamics of transnational electricity governance

    International Nuclear Information System (INIS)

    Recent transnational blackouts exposed two radically opposed interpretations of Europe's electricity infrastructure, which inform recent and ongoing negotiations on transnational electricity governance. To EU policy makers such blackouts revealed the fragility of Europe's power grids and the need of a more centralized form of governance, thus legitimizing recent EU interventions. Yet to power sector spokespersons, these events confirmed the reliability of transnational power grids and the traditional decentralized governance model: the disturbances were quickly contained and repaired. This paper inquires the historic legacies at work in these conflicting interpretations and associated transnational governance preferences. It traces the power sector's interpretation to its building of a secure transnational power grid from the 1950s through the era of neoliberalization. Next it places the EU interpretation and associated policy measures against the historical record of EU attempts at transnational infrastructure governance. Uncovering the historical roots and embedding of both interpretations, we conclude that their divergence is of a surprisingly recent date and relates to the current era of security thinking. Finally we recommend transnational, interpretative, and historical analysis to the field of critical infrastructure studies.

  11. Optimum depressurization and an alternate injection strategy for a station blackout event

    International Nuclear Information System (INIS)

    Since the crisis at the Fukushima plants, the severe accident progression during a station blackout accident in nuclear power plants is recognized as a very important area for accident management and emergency planning. A station blackout (SBO) scenario for an APR1400 nuclear power plant is simulated using the MELCOR computer code. A reactor coolant system (RCS) depressurization by a safety depressurization system (SDS) for water to be injected into the reactor pressure vessel (RPV) is performed as a mitigation action. The purpose of this study is to investigate the effect of the SDS actuation timing on the accident progression and determine the optimum depressurization strategy to prevent core damage and a reactor vessel failure. SBO without SDS actuation is analyzed as a base case to understand the main phenomena during SBO accident. In base case, the RPV lower head will fail after 4.2 hours since SBO occurs. SBO with SDS actuation is performed by changing the SDS actuation timing to inject water into RPV. The results show that the RPV lower head failure can be prevented if SDS is opened no later than 3.5 hour. Sensitivity study on some main parameters in MELCOR is also performed to see the effect of these parameters on the failure time of the lower head in an SBO accident. (author)

  12. Silencing Boko Haram: Mobile Phone Blackout and Counterinsurgency in Nigeria’s Northeast region

    Directory of Open Access Journals (Sweden)

    Jacob Udo-Udo Jacob

    2015-03-01

    Full Text Available In the summer of 2013, the Nigerian military, as part of its counterinsurgency operations against Boko Haram insurgents, shut down GSM mobile telephony in three northeast states – Adamawa, Borno and Yobe. This article explores the rationale, impact and citizens’ opinion of the mobile phone blackout. It draws on focus group discussions with local opinion leaders and in-depth personal interviews with military and security insiders, as well as data of Boko Haram incidences before, during and after the blackout from military sources and conflict databases. It argues that, although the mobile phone shutdown was ‘successful’ from a military- tactical point of view, it angered citizens and engendered negative opinions toward the state and new emergency policies. While citizens developed various coping and circumventing strategies, Boko Haram evolved from an open network model of insurgency to a closed centralized system, shifting the center of its operations to the Sambisa Forest. This fundamentally changed the dynamics of the conflict. The shutdown demonstrated, among others, that while ICTs serve various desirable purposes for developing states, they will be jettisoned when their use challenges the state’s legitimacy and raison d'être, but not without consequences.

  13. Demonstration of fully coupled simplified extended station black-out accident simulation with RELAP-7

    International Nuclear Information System (INIS)

    The RELAP-7 code is the next generation nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). A number of physical components with simplified two phase flow capability have been developed to support the simplified boiling water reactor (BWR) extended station blackout (SBO) analyses. The demonstration case includes the major components for the primary system of a BWR, as well as the safety system components for the safety relief valve (SRV), the reactor core isolation cooling (RCIC) system, and the wet well. Three scenarios for the SBO simulations have been considered. Since RELAP-7 is not a severe accident analysis code, the simulation stops when fuel clad temperature reaches damage point. Scenario I represents an extreme station blackout accident without any external cooling and cooling water injection. The system pressure is controlled by automatically releasing steam through SRVs. Scenario II includes the RCIC system but without SRV. The RCIC system is fully coupled with the reactor primary system and all the major components are dynamically simulated. The third scenario includes both the RCIC system and the SRV to provide a more realistic simulation. This paper will describe the major models and discuss the results for the three scenarios. The RELAP-7 simulations for the three simplified SBO scenarios show the importance of dynamically simulating the SRVs, the RCIC system, and the wet well system to the reactor safety during extended SBO accidents. (author)

  14. Station blackout accidents for the Korea Nuclear Unit 1 using RELAP5/MOD1

    International Nuclear Information System (INIS)

    A station blackout accident which occured at the Korea Nuclear Unit 1 (KNU-1) at the Kori site in Korea on June 9, 1981 was analyzed by using the RELAP5/MOD1 code. The incident was occured at 11:05 a.m. due to the malfunction of a steam generator level gauge. The false level signal eventually caused the reactor and turbine trip. Following the turbine trip, the excitor of the generator remained functioning and the reactor coolant pumps remained connected to the internal source for 30 seconds, thus providing full reactor coolant flow for 30 seconds after the reactor trip. Upon the loss of the generator power, one of two buses failed to automatically transfer to the off-site power and the other also failed in 30 seconds after generator trip. The transfer to the off-site power was restored in about 26 minutes. During the blackout period two diesel generators provided the necessary electrical power to the corresponding instruments and two motor-driven auxiliary feedwater pumps

  15. Analysis of long-term station blackout at Peach Bottom using MELCOR

    International Nuclear Information System (INIS)

    MELCOR is a fully integrated computer code that models all phases of the progression of severe accidents in nuclear power plants. It is being developed for the US Nuclear Regulatory Commission (NRC) by Sandia National Laboratories and is designed to provide an improved severe-accident/source term analysis capability relative to the older source term code package (STCP). Brookhaven National Laboratory has a program with the NRC to verify and apply the MELCOR code to severe-accident analysis for several plants. This paper presents the results from a MELCOR calculation of a long-term station blackout accident sequence with failure to depressurize the reactor vessel. Peach Bottom, a boiling water reactor with Mark I containment, was used in the analysis. The paper also compared MELCOR predictions with STCP calculations for the same sequence. This sequence assumes that batteries are available for 6 h following loss of all power to the plant. Station blackout sequences have often been determined to be important contributors to the risk from severe accidents. Following battery failure, the reactor coolant system (RCS) inventory is boiled off through the relief valves by continued decay heat generation. This leads to core uncovery, heat-up, clad oxidation, core degradation, relocation, and, eventually, vessel failure at high pressure. The STCP has calculated the transient up to 13.5 h after core uncovery. MELCOR calculations have been carried out to 16.7 after core uncovery. The results include the release of source terms to the environment

  16. MELCOR simulation of long-term station blackout at Peach Bottom

    International Nuclear Information System (INIS)

    MELCOR is a fully integrated computer code that models all phases of the progression of severe accidents in nuclear power plants. It is being developed for the U.S. Nuclear Regulatory Commission by Sandia National Laboratories (SNL), and is designed to provide an improved severe accident/source term analysis capability relative to the older Source Term Code Package (STCP). BNL has a program with the NRC to verify and apply the MELCOR code to severe accident analysis for several plants. This paper presents the results from a MELCOR calculation of a Long-Term Station Blackout Accident Sequence with failure to depressurize the reactor vessel. Peach Bottom, a boiling water reactor with Mark I containment, was used in the analysis. The paper also compares MELCOR predictions with STCP calculations for the same sequence. This sequence assumes that batteries are available for six hours following loss of all power to the plant. Station blackout sequences have often been determined to be important contributors to the risk from severe accidents. Following battery failure, the reactor coolant system (RCS) inventory is boiled off through the relief valves by continued decay heat generation. This leads to core uncovery, heatup, clad oxidation, core degradation, relocation, and eventually, vessel failure at high pressure. STCP has calculated the transient out to 13.5 hours after core uncovery. MELCOR calculations have been carried out to 16.7 hours after core uncovery. The results include the release of source terms to the environment

  17. Emergency procedure control for station blackout in the experimental fast reactor Joyo

    International Nuclear Information System (INIS)

    After the 2011 off the Pacific Coast of Tohoku Earthquake and the Fukushima Daiichi Nuclear Power Station accident on March 11, 2011, the safety ensuring of reactor facilities at the time of power source function loss has been required more than ever. The Nuclear Regulatory Commission was established in September 2013, and the study on safety standards has been promoted in the framework of new regulations. In Joyo, under these circumstances, voluntary review and countermeasures are advancing in order to improve corresponding measures against power source function loss. As one of such efforts, guidelines in case of station blackout were prepared. In the sodium-cooled fast reactor 'Joyo', it is possible as plant characteristics that the core decay heat can be removed by natural circulation cooling even when the forced cooling function has been lost. Moreover, since power supply from an uninterruptible power supply system is possible even after station blackout, necessary monitoring functions can be maintained, However, it is necessary to consider the response measures for the discharge of storage battery. This paper reports the contents of study on corresponding measures for the incident from the start to end, as well as the contents of the preparation for the equipment for temporary power supply etc., and the training that was carried out on the assumption of the same incident. (A.O.)

  18. ESBWR response to an extended station blackout/loss of all AC power

    International Nuclear Information System (INIS)

    U.S. federal regulations require light water cooled nuclear power plants to cope with Station Blackouts for a predetermined amount of time based on design factors for the plant. U.S. regulations define Station Blackout (SBO) as a loss of the offsite electric power system concurrent with turbine trip and unavailability of the onsite emergency AC power system. According to U.S. regulations, typically the coping period for an SBO is 4 hours and can be as long as 16 hours for currently operating BWR plants. Being able to cope with an SBO and loss of all AC power is required by international regulators as well. The U.S. licensing basis for the ESBWR is a coping period of 72 hours for an SBO based on U.S. NRC requirements for passive safety plants. In the event of an extended SBO (viz., greater than 72 hours), the ESBWR response shows that the design is able to cope with the event for at least 7 days without AC electrical power or operator action. ESBWR is a Generation III+ reactor design with an array of passive safety systems. The ESBWR primary success path for mitigation of an SBO event is the Isolation Condenser System (ICS). The ICS is a passive, closed loop, safety system that initiates automatically on a loss of power. Upon Station Blackout or loss of all AC power, the ICS begins removing decay heat from the Reactor Pressure Vessel (RPV) by (i) condensing the steam into water in heat exchangers located in pools of water above the containment, and (ii) transferring the decay heat to the atmosphere. The condensed water is then returned by gravity to cool the reactor again. The ICS alone is capable of maintaining the ESBWR in a safe shutdown condition after an SBO for an extended period. The fuel remains covered throughout the SBO event. The ICS is able to remove decay heat from the RPV for at least 7 days and maintains the reactor in a safe shutdown condition. The water level in the RPV remains well above the top of active fuel for the duration of the SBO event

  19. Safety Requirements to Face Nuclear Power Plants Blackout Using Standby Gas Turbine Generator

    International Nuclear Information System (INIS)

    The main function of nuclear power plant safety systems is to prevent damage to the reactor and the release of radioactive materials into the surroundings following an occurrence that interrupts normal power plant operation. Recent nuclear regulations concerning the emergency power generating facilities in nuclear power plants consider diesel engines only for the application which is n't the best choice for stand by generation needs. In this paper the main goal is to determine the main characteristic of Diesel Generator (DG) and Gas Turbine Generator (GTG) and justify the main general requirements for a station blackout power sources using gas turbine generator instead of commonly used diesel generators to bring multiplicity to the design of the nuclear unit

  20. AP1000 plant pressurizer overfilling prevention study against station blackout accident

    International Nuclear Information System (INIS)

    If loss of main feed-water occurs in a station blackout accident for AP1000 plant, the pressurizer will overfill and the coolant will be discharged through pressurizer safety valves. It results in a loss of coolant accident, RCS inventory will decrease, and the risk of reactor core uncovering increases. Because of the coolant discharging, the atmosphere radiation level in the containment may be raised, while the possibility of radioactive release to the environment increases. In order to prevent pressurizer overfilling, an effective strategy to avoid and mitigate pressurizer overfilling was provided. The results show that increasing heat transfer areas of PRHRS heat exchanger can prevent pressurizer overfilling; reasonable decreasing of IRWST back pressure can enhance mar gins of pressurizer overfilling, and mitigate pressurizer overfilling phenomena; increasing pressurizer volumes can also avoid pressurizer overfilling. The conclusions have reference value in helping design and safety analysis of AP1000 plant. (authors)

  1. Muerte por sumersión debida a shallow water blackout

    Directory of Open Access Journals (Sweden)

    J.L. Palomo Rando

    2014-09-01

    Full Text Available El llamado shallow water blackout, o síncope de las aguas superficiales, es un accidente que pueden sufrir los buceadores y llevarles a la muerte por sumersión. La natación sumergido (buceando precedida de hiperventilación crea una situación en la que el sujeto puede sufrir hipoxia antes de que la concentración en sangre arterial de dióxido de carbono alcance el nivel que le obligue a salir a la superficie a respirar. En esta situación, el sujeto inconsciente puede respirar bajo el agua y morir por sumersión.

  2. Analysis of station blackout accidents for the Bellefonte pressurized water reactor

    International Nuclear Information System (INIS)

    An analysis has been performed for the Bellefonte PWR Unit 1 to determine the containment loading and the radiological releases into the environment from a station blackout accident. A number of issues have been addressed in this analysis which include the effects of direct heating on containment loading, and the effects of fission product heating and natural convection on releases from the primary system. The results indicate that direct heating which involves more than about 50% of the core can fail the Bellefonte containment, but natural convection in the RCS may lead to overheating and failure of the primary system piping before core slump, thus, eliminating or mitigating direct heating. Releases from the primary system are significantly increased before vessel breach due to natural circulation and after vessel breach due to reevolution of retained fission products by fission product heating of RCS structures

  3. Station blackout analysis of nuclear power plant using source term code package

    International Nuclear Information System (INIS)

    Continuous efforts to ensure the safety of nuclear installations in Slovenia have led to comprehensive analysis of Levels II and III of hypothetic station blackout accident modelled using the tools at our disposal. This paper represents the thermal hydraulic and radionuclide transport part of the overall effort. MARCH3 and VANESA modules of Source Term Code Package were used to analyze four different scenario depending on different reactor coolant pump leak rate (125 gpm and 400 gpm, respectively) and containment design pressure (i.e. 0.309 Mpa and 0.785 Mpa). The final aim of the project was to prepare input into the Level III analyses of the accident. The accident starts by loss of off-site power combined with loss of diesel generators. The turbine driven auxiliary feedwater pump operates additional two hours after the inception of the accident. The results are given in form of graphs displaying reactor coolant system and containment parameters. (author)

  4. Proposed SPAR Modeling Method for Quantifying Time Dependent Station Blackout Cut Sets

    Energy Technology Data Exchange (ETDEWEB)

    John A. Schroeder

    2010-06-01

    Abstract: The U.S. Nuclear Regulatory Commission’s (USNRC’s) Standardized Plant Analysis Risk (SPAR) models and industry risk models take similar approaches to analyzing the risk associated with loss of offsite power and station blackout (LOOP/SBO) events at nuclear reactor plants. In both SPAR models and industry models, core damage risk resulting from a LOOP/SBO event is analyzed using a combination of event trees and fault trees that produce cut sets that are, in turn, quantified to obtain a numerical estimate of the resulting core damage risk. A proposed SPAR method for quantifying the time-dependent cut sets is sometimes referred to as a convolution method. The SPAR method reflects assumptions about the timing of emergency diesel failures, the timing of subsequent attempts at emergency diesel repair, and the timing of core damage that may be different than those often used in industry models. This paper describes the proposed SPAR method.

  5. New time-line technique for station blackout core-melt analysis

    International Nuclear Information System (INIS)

    Florida Power Corporation (FPC) has developed a new method for analyzing station blackout (SBO) core-melt accidents. This method, created during the recent probabilistic risk assessment (PRA) of Crystal River Unit 3 (CR-3), originated from the need to analyze the interactions among the two-train emergency feedwater (EFW) system, station batteries, and diesel generators (DGs) following a loss of off-site power (LOSP) event. SBO core-melt sequences for CR-3 are unique since the time core-melt commences depends on which DG fails last. The purpose of this paper is to outline the new method of analysis of SBO core-melt accidents at CR-3. The significance of SBO core-melt accidents to total plant risk, along with the efficacy of various methods to reduce SBO risk, are also discussed

  6. Blackout sequence modeling for Atucha-I with MARCH3 code

    International Nuclear Information System (INIS)

    The modeling of a blackout sequence in Atucha I nuclear power plant is presented in this paper, as a preliminary phase for a level II probabilistic safety assessment. Such sequence is analyzed with the code MARCH3 from STCP (Source Term Code Package), based on a specific model developed for Atucha, that takes into accounts it peculiarities. The analysis includes all the severe accident phases, from the initial transient (loss of heat sink), loss of coolant through the safety valves, core uncovered, heatup, metal-water reaction, melting and relocation, heatup and failure of the pressure vessel, core-concrete interaction in the reactor cavity, heatup and failure of the containment building (multi-compartmented) due to quasi-static overpressurization. The results obtained permit to visualize the time sequence of these events, as well as provide the basis for source term studies. (author)

  7. Applied use of combustion turbine generators as a station blackout alternate AC power source

    International Nuclear Information System (INIS)

    In response to the 10 CFR 50.63 Station Blackout Rule and NRC Regulatory Guide (RG) 1.155, Arizona Public Service Company (APS) opted to install dual 13.8kV, 3400kW black start combustion turbine generators (CTG's) as an alternate AC (AAC) power source at the Palo Verde Nuclear Generating Station (PVNGS). These CTG's provide AC power to critical plant loads in the event of a Station Blackout (SBO) in any one of the three PVNGS units. The AAC power source entered service in the fall of 1993 for the first PVNGS unit. Connection of the AAC source for the other two nuclear units will be complete by mid-1995. Two redundant CTGs were used to provide assurance that the AAC system availability requirements of RG 1.155 of 95% were met. A CTG site was chosen near an existing source of diesel fuel oil that was reasonably distant from the plant switchyard. The CTG's were installed along with a prefabricated turbine control room (TCR) which houses the CTG control equipment and associated power distribution equipment and battery systems. Cables were routed from the CTG site to each of the PVNGS units utilizing both new and existing underground duct banks. The cables were sized for the combined output of both CTG's at maximum power output for site worst case conditions. At each of the PVNGS units, additional switchgear cubicles were added to provide an interface with the existing plant power distribution system at a point upstream of the safety related power system. A test program was developed by engineering that tested all aspects of the installation and proved its capability to fulfill its purpose. Testing ranged from verifying emergency lighting adequacy to emissions testing and a complete simulation of a SBO. CTG performance was evaluated and verified to meet all expectations

  8. Demonstration of fully coupled simplified extended station black-out accident simulation with RELAP-7

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Haihua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Hongbin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zou, Ling [Idaho National Lab. (INL), Idaho Falls, ID (United States); Anders, David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Martineau, Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-10-01

    The RELAP-7 code is the next generation nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). The RELAP-7 code develop-ment effort started in October of 2011 and by the end of the second development year, a number of physical components with simplified two phase flow capability have been de-veloped to support the simplified boiling water reactor (BWR) extended station blackout (SBO) analyses. The demonstration case includes the major components for the primary system of a BWR, as well as the safety system components for the safety relief valve (SRV), the reactor core isolation cooling (RCIC) system, and the wet well. Three scenar-ios for the SBO simulations have been considered. Since RELAP-7 is not a severe acci-dent analysis code, the simulation stops when fuel clad temperature reaches damage point. Scenario I represents an extreme station blackout accident without any external cooling and cooling water injection. The system pressure is controlled by automatically releasing steam through SRVs. Scenario II includes the RCIC system but without SRV. The RCIC system is fully coupled with the reactor primary system and all the major components are dynamically simulated. The third scenario includes both the RCIC system and the SRV to provide a more realistic simulation. This paper will describe the major models and dis-cuss the results for the three scenarios. The RELAP-7 simulations for the three simplified SBO scenarios show the importance of dynamically simulating the SRVs, the RCIC sys-tem, and the wet well system to the reactor safety during extended SBO accidents.

  9. Contributions of the restructuring of the electric power industry to the August 14, 2003 blackout

    Energy Technology Data Exchange (ETDEWEB)

    Casazza, J.; Delea, F.; Loehr, G. [Power Engineers Supporting Truth, Springfield, VA (United States)

    2005-07-01

    A review of the roles of industry and government in the 2003 blackout was presented. This white paper was prepared by a group of engineers with high level experience in the electric power industry who are concerned that deregulation of the industry has led to a significant decrease in reliability. It was noted that post-blackout reviews have focused on technical failures instead of examining the responsibilities and failures of the National Electric Reliability Council (NERC). Deficiencies in the analytical capabilities of control centres were discussed, as well as issues concerning communication protocols and training. Deregulation and the concomitant restructuring of the electric power industry has led to a shift from long term optimization, inter-system coordination and reliability towards dependence on immediate profits. In addition, there have been significant reductions in personnel at electric power organizations and companies, as well as increasing complexity in operations. Increased complexity has resulted in a dilution of management responsibility, as well as over-reliance on markets to solve scientifically complex problems. There have also been cutbacks in training and research. The functional separation of generation and transmission within companies has contributed to the diffusion of best technical knowledge. Many private utilities have divested their generation resources in response to regulatory pressures. The entrance of merchant power plants in the power system has led to the establishment of new market areas that are inconsistent with the boundaries of responsible operating entities. It was concluded that all these changes have created a more complicated and compartmentalized industry structure. Decisions are now made by a large number of entities, most of which are competitors and each of which has more interest in profit than in bulk power system reliability. Procedural rules established between and among the various parties are no longer

  10. Contributions of the restructuring of the electric power industry to the August 14, 2003 blackout

    International Nuclear Information System (INIS)

    A review of the roles of industry and government in the 2003 blackout was presented. This white paper was prepared by a group of engineers with high level experience in the electric power industry who are concerned that deregulation of the industry has led to a significant decrease in reliability. It was noted that post-blackout reviews have focused on technical failures instead of examining the responsibilities and failures of the National Electric Reliability Council (NERC). Deficiencies in the analytical capabilities of control centres were discussed, as well as issues concerning communication protocols and training. Deregulation and the concomitant restructuring of the electric power industry has led to a shift from long term optimization, inter-system coordination and reliability towards dependence on immediate profits. In addition, there have been significant reductions in personnel at electric power organizations and companies, as well as increasing complexity in operations. Increased complexity has resulted in a dilution of management responsibility, as well as over-reliance on markets to solve scientifically complex problems. There have also been cutbacks in training and research. The functional separation of generation and transmission within companies has contributed to the diffusion of best technical knowledge. Many private utilities have divested their generation resources in response to regulatory pressures. The entrance of merchant power plants in the power system has led to the establishment of new market areas that are inconsistent with the boundaries of responsible operating entities. It was concluded that all these changes have created a more complicated and compartmentalized industry structure. Decisions are now made by a large number of entities, most of which are competitors and each of which has more interest in profit than in bulk power system reliability. Procedural rules established between and among the various parties are no longer

  11. Demonstration of fully coupled simplified extended station black-out accident simulation with RELAP-7

    International Nuclear Information System (INIS)

    The RELAP-7 code is the next generation nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). The RELAP-7 code develop-ment effort started in October of 2011 and by the end of the second development year, a number of physical components with simplified two phase flow capability have been de-veloped to support the simplified boiling water reactor (BWR) extended station blackout (SBO) analyses. The demonstration case includes the major components for the primary system of a BWR, as well as the safety system components for the safety relief valve (SRV), the reactor core isolation cooling (RCIC) system, and the wet well. Three scenar-ios for the SBO simulations have been considered. Since RELAP-7 is not a severe acci-dent analysis code, the simulation stops when fuel clad temperature reaches damage point. Scenario I represents an extreme station blackout accident without any external cooling and cooling water injection. The system pressure is controlled by automatically releasing steam through SRVs. Scenario II includes the RCIC system but without SRV. The RCIC system is fully coupled with the reactor primary system and all the major components are dynamically simulated. The third scenario includes both the RCIC system and the SRV to provide a more realistic simulation. This paper will describe the major models and dis-cuss the results for the three scenarios. The RELAP-7 simulations for the three simplified SBO scenarios show the importance of dynamically simulating the SRVs, the RCIC sys-tem, and the wet well system to the reactor safety during extended SBO accidents.

  12. OPTIMUM STEADY STATE LOAD SHEDDING USING SHUFFLED FROG LEAPING ALGORITHM TO AVERT BLACKOUT IN POWER SYSTEMS DURING OVERLOAD AND GENERATION CONTINGENCIES

    OpenAIRE

    R. MAGESHVARAN; T. Jayabarathi; VAIBHAV SHAH; SHIVAM SOOD

    2015-01-01

    During generation and overload contingencies in a power system, the system voltage and frequency will decline due to the deficiency of real and reactive powers. Consequently cascaded failures may occur which will lead to complete blackout of certain parts of the power system. Load shedding is considered as the ultimate step of emergency control action that is necessary to prevent a blackout in the power system. This paper proposes a memetic meta-heuristic algorithm known as shuffled frog leap...

  13. Long-Term Station Blackout Accident Analyses of a PWR with RELAP5/MOD3.3

    OpenAIRE

    Andrej Prošek; Leon Cizelj

    2013-01-01

    Stress tests performed in Europe after accident at Fukushima Daiichi also required evaluation of the consequences of loss of safety functions due to station blackout (SBO). Long-term SBO in a pressurized water reactor (PWR) leads to severe accident sequences, assuming that existing plant means (systems, equipment, and procedures) are used for accident mitigation. Therefore the main objective was to study the accident management strategies for SBO scenarios (with different reactor coolant pump...

  14. Evaluation of station blackout accidents at nuclear power plants: Technical findings related to unresolved safety issue A-44: Final report

    Energy Technology Data Exchange (ETDEWEB)

    1988-06-01

    ''Station Blackout,'' which is the complete loss of alternating current (AC) electrical power in a nuclear power plant, has been designated as Unresolved Safety Issue A-44. Because many safety systems required for reactor core decay heat removal and containment heat removal depend on AC power, the consequences of a station blackout could be severe. This report documents the findings of technical studies performed as part of the program to resolve this issue. The important factors analyzed include: the fequency of loss of offsite power; the probability that emergency or onsite AC power supplies would be unavailable; the capability and reliability of decay heat removal systems independent of AC power; and the likelihood that offsite power would be restored before systems that cannot operate for extended periods without AC power fail, thus resulting in core damage. This report also addresses effects of different designs, locations, and operational features on the estimated frequency of core damage resulting from station blackout events.

  15. Performance Evaluation of Target Detection with a Near-Space Vehicle-Borne Radar in Blackout Condition.

    Science.gov (United States)

    Li, Yanpeng; Li, Xiang; Wang, Hongqiang; Deng, Bin; Qin, Yuliang

    2016-01-01

    Radar is a very important sensor in surveillance applications. Near-space vehicle-borne radar (NSVBR) is a novel installation of a radar system, which offers many benefits, like being highly suited to the remote sensing of extremely large areas, having a rapidly deployable capability and having low vulnerability to electronic countermeasures. Unfortunately, a target detection challenge arises because of complicated scenarios, such as nuclear blackout, rain attenuation, etc. In these cases, extra care is needed to evaluate the detection performance in blackout situations, since this a classical problem along with the application of an NSVBR. However, the existing evaluation measures are the probability of detection and the receiver operating curve (ROC), which cannot offer detailed information in such a complicated application. This work focuses on such requirements. We first investigate the effect of blackout on an electromagnetic wave. Performance evaluation indexes are then built: three evaluation indexes on the detection capability and two evaluation indexes on the robustness of the detection process. Simulation results show that the proposed measure will offer information on the detailed performance of detection. These measures are therefore very useful in detecting the target of interest in a remote sensing system and are helpful for both the NSVBR designers and users. PMID:26751445

  16. Depressurization analyses of PWR station blackout with MELCOR 1.8.4

    International Nuclear Information System (INIS)

    A total station blackout (SBO) accident sequence, namely TMLB', of PWR was found as a dominant accident leading to core severe damage. IT was also found that the sequence could lead to High Pressure Melt Ejection (HPME) followed by Direct Containment Heating (DCH), and, in turn, challenge the containment integrity. An intentional RCS depressurization had been proposed to prevent or mitigate the effects of DCH during a station blackout. Moreover, during such sequence, a primary coolant pump seal might be deteriorated due to loss of cooling. This particular LOCA is designated as S3-TMLB'. This report describes the analytical studies for variations of a TMLB' sequence of PWR four loops plant of Indian Point 3. The analyses also include S3-TMLB' with or without RCS depressurization and a series of sensitivity analyses. Analytical tool used in this calculation is the MELCOR 1.8.4 code. Seven runs of different scenario have been performed. For the TMLB' accident, the calculation results predicted a vessel breach as a result of debris relocation in lower plenum, while the RCS pressure was kept at PORV set point. Such condition could allow a HPME. On the other hand, the RCP seal leak during TMLB', might give the different effects on accident sequence depending on the timing of the seals failure. Early failure after initiation of SBO, i.e. 10 minutes, resulted in an early core damage. Contrarily, if the seal failure occur later, the core damage could delay from about 2000 s to more than 1 hr compared to the TMLB' sequence. An intentional RCS depressurization by PORVs latched open during TMLB' did not show an important effect; the predicted sequence was similar to TMLB'. But, if the discharging valves flow area is increased, which is assumed by SRVs latched open together with PORVs in this study, the core damage progression could be delayed by about 6000 s. This last strategy was also applied to S3-TMLB' accident. However, the calculation result showed that, compared to the

  17. The Safety Assessment of OPR-1000 for Station Blackout Applying Combined Deterministic and Probabilistic Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dong Gu; Ahn, Seung-Hoon; Cho, Dae-Hyung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-05-15

    This is termed station blackout (SBO). However, it does not generally include the loss of available AC power to safety buses fed by station batteries through inverters or by alternate AC sources. Historically, risk analysis results have indicated that SBO was a significant contributor to overall core damage frequency. In this study, the safety assessment of OPR-1000 nuclear power plant for SBO accident, which is a typical beyond design basis accident and important contributor to overall plant risk, is performed by applying the combined deterministic and probabilistic procedure (CDPP). In addition, discussions are made for reevaluation of SBO risk at OPR-1000 by eliminating excessive conservatism in existing PSA. The safety assessment of OPR-1000 for SBO accident, which is a typical BDBA and significant contributor to overall plant risk, was performed by applying the combined deterministic and probabilistic procedure. However, the reference analysis showed that the CDF and CCDP did not meet the acceptable risk, and it was confirmed that the SBO risk should be reevaluated. By estimating the offsite power restoration time appropriately, the SBO risk was reevaluated, and it was finally confirmed that current OPR-1000 system lies in the acceptable risk against the SBO. In addition, it was demonstrated that the proposed CDPP is applicable to safety assessment of BDBAs in nuclear power plants without significant erosion of the safety margin.

  18. The Optimum Operation Strategy of Hybrid SIT with PAFS following a Station Blackout Accident

    International Nuclear Information System (INIS)

    A coolant storage tank of PAFS can provide coolant for reactor cooling more than 8 hours and a dedicated battery system of PAFS can provide electricity for I-C more than 72 hours. PAFS is 2-train system, that is, PAFS has two water tanks, two battery systems and two heat exchangers. PAFS provides feedwater to steam generator more than 8 hours, even if single train was unavailable, AC power was not provided and water tank is not refilled. Following Fukushima Daiichi Accident, we have made many improvements and challenging research to prevent and mitigate accidents which can be caused by earthquake, tsunami or station blackout. It includes the Hybrid SIT to deliver cooling water into core even if RCS pressure is high. To prevent a waste of SIT water and maintain core cooling more long time, an optimum operation strategy of Hybrid SIT has been developed. It considers the operation of PAFS and the optimum coolability of SIT water. For the optimum coolability of Hybrid SIT with PAFS, some operation methods were considered. It shows that the coolant injected before the swelling of RCS water is released during the first POSRV opening and has very little effect on core cooling. The core cooling period is longest when the Hybrid SIT is actuated one by one after a exhaustion of PAFS and POSRV opening

  19. Assessment of the potential for HPME during a station blackout in the Surry and Zion PWRS

    International Nuclear Information System (INIS)

    The integrity of a PWR (pressurized water reactor) containment structure could be challenged by direct heating associated with a HPME (high pressure melt ejection) of core materials following reactor vessel lower head breach during certain severe accidents. Structural failure resulting from direct containment heating is a contributor to the risk of operating a PWR. Intentional RCS (reactor coolant system) depressurization, where operators latch pressurizer relief valves open, has been proposed as an accident management strategy to reduce those risks by mitigating the severity of the HPME. However, decay heat levels, valve capacities, and other plant-specific characteristics determine whether the required operator action will be effective. Without operator action, natural circulation flows could heat ex-vessel RCS pressure boundaries (surge line and hot leg piping, steam generator tubes, etc.) to the point of failure before failure of the lower head providing an unintentional mechanism for depressurization and HPME mitigation. This paper summarizes an assessment of RCS depressurization with respect to the potential for HPME during a station blackout in the Surry and Zion PWRs. The assessment included a detailed transient analysis using the SCDAP/RELAP5/MOD3 computer code and an evaluation of RCS depressurization-related probabilities primarily based on the code results

  20. SCDAP/RELAP5 analysis of station blackout with pump seal LOCA in Surry plant

    International Nuclear Information System (INIS)

    During a station blackout of PWR, the pump seal will fail due to loss of the seal cooling. This particular transient-LOCA sequence designated as S3-TMLB' analyzed by SNL with MELPROG/TRAC for Surry plant showed that the depressurization due to the pump seal LOCA would result in early accumulator injection and subsequent core cooling which lead to the delay of reactor pressure vessel (RPV) meltthrough. The present analysis was performed with SCDAP/RELAP5 to evaluate this scenario shown in the MELPROG/TRAC analyses. Additionally, the calculated results were compared with the similar experimental studies of JAERI's ROSA-IV program. The present analyses showed that: (1) During S3-TMLB', the loop seal clearing would occur and cause a slight delay of accident progression. (2) It is unlikely that the accumulator injection, which leads to the delay of RPV meltthrough by approximately 60 min, is initiated automatically during S3-TMLB'. Accordingly, an intentional depressurization using PORVs is recommended for the mitigation of the accident consequences. (3) The present SCDAP/RELAP5 analyses did not show significant delay of accident progression. It was found that non-realistic lower heat generation and higher core cooling models used in the MELPROG/TRAC analysis are attributed to this discrepancy. (author)

  1. Test study on safety features of station blackout accident for nuclear main pump

    International Nuclear Information System (INIS)

    The theoretical and experimental studies of reactor coolant pump accidents encountered nation-wide and world-wide were described. To investigate the transient hydrodynamic performance of reactor coolant pump (RCP) during the period of rotational inertia in the station blackout accident, some theoretical and experimental studies were carried out, and the analysis of the test results was presented. The experiment parameters, conditions and test methods were introduced. The flow-rate, rotate speed and vibrations were analyzed emphatically. The quadruplicate polynomial curve equation was used to simulate the flow-rate,rotate speed along with time. The test results indicate that the flow-rate and rotator speed decrease rapidly at the very beginning of cut power and the test results accord with the regulation of safety standard. The vibrant displacement of bearing seat is intensified at the moment of lose power, but after a certain period rotor shaft libration changes. The test and analysis results help to understand the hydrodynamic performance of nuclear primary pump under lost of power accident, and provide the basic reference for safety evaluation. (authors)

  2. Case Study of Multi-Unit Risk: Multi-Unit Station Black-Out

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Kyemin; Jang, Seung-cheol [KAERI, Daejeon (Korea, Republic of); Heo, Gyunyoung [Kyung Hee University, Yongin (Korea, Republic of)

    2015-05-15

    After Fukushima Daiichi Accident, importance and public concern for Multi-Unit Risk (MUR) or Probabilistic Safety Assessment (PSA) have been increased. Most of nuclear power plant sites in the world have more than two units. These sites have been facing the problems of MUR or accident such as Fukushima. In case of South Korea, there are generally more than four units on the same site and even more than ten units are also expected. In other words, sites in South Korea also have been facing same problems. Considering number of units on the same site, potential of these problems may be larger than other countries. The purpose of this paper is to perform case study based on another paper submitted in the conference. MUR is depended on various site features such as design, shared systems/structures, layout, environmental condition, and so on. Considering various dependencies, we assessed Multi-Unit Station Black-out (MSBO) accident based on Hanul Unit 3 and 4 model. In this paper, case study for multi-unit risk or PSA had been performed. Our result was incomplete to assess total multi-unit risk because of two challenging issues. First, economic impact had not been evaluated to estimate multi-unit risk. Second, large uncertainties were included in our result because of various assumptions. These issues must be resolved in the future.

  3. MELCOR simulation of long-term station blackout at Peach Bottom

    International Nuclear Information System (INIS)

    This paper presents the results from MELCOR (Version 1.8BC) calculations of the long-term station blackout accident sequence, with failure to depressurize the reactor vessel, at the Peach Bottom (BWR Mark I) plant, and presents comparisons with Source Term Code Package (STCP) calculations of the same sequence. This sequence assumes that batteries are available for six hours following loss of all power to the plant. Following battery failure, the reactor coolant system (RCS) inventory is boiled off through the relief valves by continued decay heat generation. This leads to core uncovery, heatup, clad oxidation, core degradation, relocation, and, eventually, vessel failure at high pressure. STCP has calculated the transient out to 13.5 hours after core uncovery. MELCOR calculations have been carried out to 16.7 hours after core uncovery. The results include the timing of key events, pressure and temperature response in the reactor vessel and containment, hydrogen production, and the release of source terms to the environment

  4. Comparative study of the hydrogen generation during short term station blackout (STSBO) in a BWR

    International Nuclear Information System (INIS)

    Highlights: • Comparative study of generation in a simulated STSBO severe accident. • MELCOR and SCDAP/RELAP5 codes were used to understanding the main phenomena. • Both codes present similar thermal-hydraulic behavior for pressure and boil off. • SCDAP/RELAP5 predicts 15.8% lower hydrogen production than MELCOR. - Abstract: The aim of this work is the comparative study of hydrogen generation and the associated parameters in a simulated severe accident of a short-term station blackout (STSBO) in a typical BWR-5 with Mark-II containment. MELCOR (v.1.8.6) and SCDAP/RELAP5 (Mod.3.4) codes were used to understand the main phenomena in the STSBO event through the results comparison obtained from simulations with these codes. Due that the simulation scope of SCDAP/RELAP5 is limited to failure of the vessel pressure boundary, the comparison was focused on in-vessel severe accident phenomena; with a special interest in the vessel pressure, boil of cooling, core temperature, and hydrogen generation. The results show that at the beginning of the scenario, both codes present similar thermal-hydraulic behavior for pressure and boil off of cooling, but during the relocation, the pressure and boil off, present differences in timing and order of magnitude. Both codes predict in similar time the beginning of melting material drop to the lower head. As far as the hydrogen production rate, SCDAP/RELAP5 predicts 15.8% lower production than MELCOR

  5. Analysis of economics and safety to cope with station blackout in PWR

    International Nuclear Information System (INIS)

    Highlights: • Proposed framework covers all aspects of very complicated decision making. • We addressed the various options against SBO. • Emergency water supply through the steam generator hookup was considered. • Optimal testing interval of EDG was determined in various design options. • Effect of risk aversion factor on decision making was quantitatively illustrated. - Abstract: Design and operation options that can reduce both the initiating event frequency and the accident mitigation probability were addressed in an integrated framework to cope with station blackout. The safety, engineering cost, water delivery cost and testing/maintenance cost of each option were quantitatively evaluated to calculate the cost variation and to find an optimal point in the reference reactor, OPR1000. Design variables that represent additional emergency water supply, diverse emergency diesel generator, and surveillance test period modification were investigated. Based on these design variables, we applied the developed formula to quantify cost items, which were presented as changes of the economics and the safety. A case study was provided to illustrate the change of the total cost. Different risk aversion factors that represent different attitudes of the public were also investigated. The result shows that the costs and benefits of various complicated options can be effectively addressed with the proposed risk-informed decision making framework

  6. The Optimum Operation Strategy of Hybrid SIT with PAFS following a Station Blackout Accident

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Sun; Ha, Hui-Un [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2014-10-15

    A coolant storage tank of PAFS can provide coolant for reactor cooling more than 8 hours and a dedicated battery system of PAFS can provide electricity for I-C more than 72 hours. PAFS is 2-train system, that is, PAFS has two water tanks, two battery systems and two heat exchangers. PAFS provides feedwater to steam generator more than 8 hours, even if single train was unavailable, AC power was not provided and water tank is not refilled. Following Fukushima Daiichi Accident, we have made many improvements and challenging research to prevent and mitigate accidents which can be caused by earthquake, tsunami or station blackout. It includes the Hybrid SIT to deliver cooling water into core even if RCS pressure is high. To prevent a waste of SIT water and maintain core cooling more long time, an optimum operation strategy of Hybrid SIT has been developed. It considers the operation of PAFS and the optimum coolability of SIT water. For the optimum coolability of Hybrid SIT with PAFS, some operation methods were considered. It shows that the coolant injected before the swelling of RCS water is released during the first POSRV opening and has very little effect on core cooling. The core cooling period is longest when the Hybrid SIT is actuated one by one after a exhaustion of PAFS and POSRV opening.

  7. Sampling based uncertainty analysis of station blackout in PSB VVER integral test facility

    International Nuclear Information System (INIS)

    Highlights: → SBO analysis in PSB VVER ITF has been carried out using RELAP5/MOD3.2. → Uncertainty and sensitivity analysis is carried out with sampling based approach (LHS). → Experimental/code calculated values are within the uncertainty band. → Linear regression analysis is carried out to get order of importance of input parameters. → This methodology can be used for transients of NPP with any best estimate system code. - Abstract: Best estimate accident analysis with uncertainty evaluation is being encouraged in the present licensing scenarios of nuclear power plants. This paper deals with uncertainty and sensitivity analysis for station blackout in PSB VVER integral test facility under the framework of coordinated research project of IAEA. Nodalization was developed using best estimate system code RELAP5/MOD3.2 and its steady state and transient level qualifications are achieved. Sampling based approaches are used to carry out uncertainty and sensitivity/importance analysis. The objective of the analysis is to get confidence for uncertainty methodology by comparing with the experimental results and extend its applicability to NPPs. Uncertainty analysis is carried out by selecting nine important input parameters with specified ranges and its uniform distributions. A design matrix of 45 x 9 is generated for variations of input parameters with the Latin Hypercube Sampling and 45 code runs were taken. Linear regression was also carried out to quantify the effect of each individual input parameter on output parameters in terms of standard rank regression coefficients. Uncertainty band in output parameters is defined between 95th and 5th percentile value. It is observed that most of the experimental values and code calculated reference values are lying within the uncertainty band. For most of the parameters, width of uncertainty band increases with transient progression time.

  8. Analysis of Safety Margins in an Initial Stage during the KALIMER Station Blackout

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Won Pyo; Jeong, Hae Yong; Lee, Yong Bum

    2008-01-15

    The main effort in the present study contributes to investigating the safety margins by analyzing the KALIMER station blackout accident. Natural circulation becomes the main heat transfer mechanism. The flow depends mostly on pump's halving time, friction factor for the wire-wrapped rod bundles in the core, and heat transfer coefficient. Therefore, physical models concerned with heat transfer in both pipe internals (IHX/DHX tube sides) and tube bundles (core, IHX/DHX shell sides), including the core wire-wrapped rod bundles, are also to be assessed in the study. In results, the heat transfer coefficient currently featured in SSC-K for an IHX rod bundle has been found acceptable. The heat transfer coefficient used for the core rod bundle, however, has not shown suitability and thus an alternative one has been proposed. Meanwhile, the friction factor model in SSC-K has not shown a prominent discrepancy in prediction trend but it has not been backed by an enough theoretical basis so that it has been replaced by the Cheng and Todreas model. An assessment matrix has been made to analyze systematically the effects of those parameters affecting on the conservatism of the safety analysis, and the matrix is constituted with the average value and the upper/lower limits in the correlation's applicable ranges. The preliminary calculation has shown negligible effect on the fuel temperature, while the pump halving time and the friction factor for the wire-wrapped rod bundle in the core have affected on the analysis results.

  9. Blackout risk prevention in a smart grid based flexible optimal strategy using Grey Wolf-pattern search algorithms

    International Nuclear Information System (INIS)

    Highlights: • A generalized optimal security power system planning strategy for blackout risk prevention is proposed. • A Grey Wolf Optimizer dynamically coordinated with Pattern Search algorithm is proposed. • A useful optimized database dynamically generated considering margin loading stability under severe faults. • The robustness and feasibility of the proposed strategy is validated in the standard IEEE 30 Bus system. • The proposed planning strategy will be useful for power system protection coordination and control. - Abstract: Developing a flexible and reliable power system planning strategy under critical situations is of great importance to experts and industrials to minimize the probability of blackouts occurrence. This paper introduces the first stage of this practical strategy by the application of Grey Wolf Optimizer coordinated with pattern search algorithm for solving the security smart grid power system management under critical situations. The main objective of this proposed planning strategy is to prevent the practical power system against blackout due to the apparition of faults in generating units or important transmission lines. At the first stage the system is pushed to its margin stability limit, the critical loads shedding are selected using voltage stability index. In the second stage the generator control variables, the reactive power of shunt and dynamic compensators are adjusted in coordination with minimization the active and reactive power at critical loads to maintain the system at security state to ensure service continuity. The feasibility and efficiency of the proposed strategy is applied to IEEE 30-Bus test system. Results are promising and prove the practical efficiency of the proposed strategy to ensure system security under critical situations

  10. Evaluation of Station Blackout accidents at nuclear power plants. Technical findings related to Unresolved Safety Issue A-44. Draft report for comment

    International Nuclear Information System (INIS)

    ''Station Blackout,'' which is the complete loss of alternating current (ac) electrical power in a nuclear power plant, has been designated as Unresolved Safety Issue A-44. Because many safety systems required for reactor core decay heat removal and containment heat removal depend on ac power, the consequences of a station blackout could be severe. This report documents the findings of technical studies performed as part of the program to resolve this issue. The important factors analyzed include: the frequency of loss of offsite power; the probability that emergency or onsite ac power supplies would be unavailable; the capability and reliability of decay heat removal systems independent of ac power; and the likelihood that offsite power would be restored before systems that cannot operate for extended periods without ac power fail, thus resulting in core damage. This report also addresses effects of different designs, locations, and operational features on the estimated frequency of core damage resulting from station blackout events

  11. Station Black-Out Analysis with MELCOR 1.8.6 Code for Atucha 2 Nuclear Power Plant

    OpenAIRE

    Analia Bonelli; Oscar Mazzantini; Martin Sonnenkalb; Marcelo Caputo; Juan Matias García; Pablo Zanocco; Marcelo Gimenez

    2012-01-01

    A description of the results for a Station Black-Out analysis for Atucha 2 Nuclear Power Plant is presented here. Calculations were performed with MELCOR 1.8.6 YV3165 Code. Atucha 2 is a pressurized heavy water reactor, cooled and moderated with heavy water, by two separate systems, presently under final construction in Argentina. The initiating event is loss of power, accompanied by the failure of four out of four diesel generators. All remaining plant safety systems are supposed to be avail...

  12. Light Water Reactor Sustainability Program: Analysis of Pressurized Water Reactor Station Blackout caused by external flooding using the RISMC toolkit

    International Nuclear Information System (INIS)

    The existing fleet of nuclear power plants is in the process of extending its lifetime and increasing the power generated from these plants via power uprates. In order to evaluate the impacts of these two factors on the safety of the plant, the Risk Informed Safety Margin Characterization project aims to provide insights to decision makers through a series of simulations of the plant dynamics for different initial conditions (e.g., probabilistic analysis and uncertainty quantification). This paper focuses on the impacts of power uprate on the safety margin of a boiling water reactor for a flooding induced station black-out event. Analysis is performed by using a combination of thermal-hydraulic codes and a stochastic analysis tool currently under development at the Idaho National Laboratory, i.e. RAVEN. We employed both classical statistical tools, i.e. Monte-Carlo, and more advanced machine learning based algorithms to perform uncertainty quantification in order to quantify changes in system performance and limitations as a consequence of power uprate. Results obtained give a detailed investigation of the issues associated with a plant power uprate including the effects of station black-out accident scenarios. We were able to quantify how the timing of specific events was impacted by a higher nominal reactor core power. Such safety insights can provide useful information to the decision makers to perform risk informed margins management.

  13. Analysis of mitigation effect of steam-exhaust operation of the secondary circuit to ship reactor blackout accident

    International Nuclear Information System (INIS)

    According the characteristics of ship reactor, the RELAP5 models for its primary circuit and the secondary circuit were established, the ship reactor blackout accident under the economy headway condition was simulated using RELAP5/MOD3.2 code, and the mitigation effects of four different steam-exhaust schemes to the accident process were analyzed. The results show that the reasonable steam-exhaust scheme can mitigate the accident remarkably, and the delay time is about hour level: the less the steam is consumed, the longer the operation time of the equipment of the secondary circuit is, the longer the time of the heat sink of the primary circuit can last, and the slower the accident process will be. However, too little steam-exhaust flux will lead to steam generator (SG) water level excessively high or even brimming which will be a threat to normal operation of the devices in the secondary circuit. Meanwhile, there are many devices in the secondary circuit, and the limits to the minimum steam flux to operate the devices are different. Then, the most useful device with the lowest steam- exhaust flux should be chosen as the steam-exhaust operation equipment. The study can provide a reference for the emergent treatment during the ship reactor blackout accident. (authors)

  14. Advanced Technology Application Station Blackout Core Damage Frequency Reduction - The Contribution of an AC Independent Core Residual Heat Removal System

    International Nuclear Information System (INIS)

    An event of station blackout (SBO) can result in severe core damage and undesirable consequences to the public and the environment. To cope with an SBO, nuclear reactors are provided with protection systems that automatically shut down the reactor, and with safety systems to remove the core residual heat. In order to reduce core damage frequency, the design of new reactors incorporates passive systems that rely only on natural forces to operate. This paper presents an evaluation of the SBO core damage frequency of a PWR reactor being designed in Brazil. The reactor has two core residual heat removal systems - an AC dependent system, and a passive system. Probabilistic safety assessment is applied to identify failure scenarios leading to SBO core damage. The SBO is treated as an initiating event, and fault trees are developed to model those systems required to operate in SBO conditions. Event trees are developed to assist in the evaluation of the possible combinations of success or failure of the systems required to cope with an SBO. The evaluation is performed using SAPHIRE, as the software for reliability and risk assessment. It is shown that a substantial reduction in the core damage frequency can be achieved by implementing the passive system proposed for the LABGENE reactor design. Keywords: Station blackout, passive safety system, core damage frequency. (author)

  15. Station Blackout Core Damage Frequency Reduction - The Contribution of an AC Independent Core Residual Heat Removal System

    International Nuclear Information System (INIS)

    An event of station blackout (SBO) can result in severe core damage and undesirable consequences to the public and the environment. To cope with an SBO, nuclear reactors are provided with protection systems that automatically shut down the reactor, and with safety systems to remove the core residual heat. In order to reduce core damage frequency, the design of new reactors incorporates passive systems that rely only on natural forces to operate. This paper presents an evaluation of the SBO core damage frequency of a PWR reactor being designed in Brazil. The reactor has two core residual heat removal systems - an AC dependent system, and a passive system. Probabilistic safety assessment is applied to identify failure scenarios leading to SBO core damage. The SBO is treated as an initiating event, and fault trees are developed to model those systems required to operate in SBO conditions. Event trees are developed to assist in the evaluation of the possible combinations of success or failure of the systems required to cope with an SBO. The evaluation is performed using SAPHIRE, as the software for reliability and risk assessment. It is shown that a substantial reduction in the core damage frequency can be achieved by implementing the passive system proposed for the LABGENE reactor design. Keywords: Station blackout, passive safety system, core damage frequency. (author)

  16. Station Black-Out Analysis with MELCOR 1.8.6 Code for Atucha 2 Nuclear Power Plant

    International Nuclear Information System (INIS)

    A description of the results for a Station Black-Out analysis for Atucha 2 Nuclear Power Plant is presented here. Calculations were performed with MELCOR 1.8.6 YV3165 Code. Atucha 2 is a pressurized heavy water reactor, cooled and moderated with heavy water, by two separate systems, presently under final construction in Argentina. The initiating event is loss of power, accompanied by the failure of four out of four diesel generators. All remaining plant safety systems are supposed to be available. It is assumed that during the Station Black-Out sequence the first pressurizer safety valve fails stuck open after 3 cycles of water release, respectively, 17 cycles in total. During the transient, the water in the fuel channels evaporates first while the moderator tank is still partially full. The moderator tank inventory acts as a temporary heat sink for the decay heat, which is evacuated through conduction and radiation heat transfer, delaying core degradation. This feature, together with the large volume of the steel filler pieces in the lower plenum and a high primary system volume to thermal power ratio, derives in a very slow transient in which RPV failure time is four to five times larger than that of other German PWRs.

  17. Light Water Reactor Sustainability Program: Analysis of Pressurized Water Reactor Station Blackout caused by external flooding using the RISMC toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Mandelli, Diego; Smith, Curtis; Prescott, Steven; Alfonsi, Andrea; Rabiti, Cristian; Cogliati, Joshua; Kinoshita, Robert

    2014-08-01

    The existing fleet of nuclear power plants is in the process of extending its lifetime and increasing the power generated from these plants via power uprates. In order to evaluate the impacts of these two factors on the safety of the plant, the Risk Informed Safety Margin Characterization project aims to provide insights to decision makers through a series of simulations of the plant dynamics for different initial conditions (e.g., probabilistic analysis and uncertainty quantification). This paper focuses on the impacts of power uprate on the safety margin of a boiling water reactor for a flooding induced station black-out event. Analysis is performed by using a combination of thermal-hydraulic codes and a stochastic analysis tool currently under development at the Idaho National Laboratory, i.e. RAVEN. We employed both classical statistical tools, i.e. Monte-Carlo, and more advanced machine learning based algorithms to perform uncertainty quantification in order to quantify changes in system performance and limitations as a consequence of power uprate. Results obtained give a detailed investigation of the issues associated with a plant power uprate including the effects of station black-out accident scenarios. We were able to quantify how the timing of specific events was impacted by a higher nominal reactor core power. Such safety insights can provide useful information to the decision makers to perform risk informed margins management.

  18. Economic simplified boiling water reactor (ESBWR) response to an extended station blackout/ loss of all AC power

    International Nuclear Information System (INIS)

    U.S. federal regulations require light water cooled nuclear power plants to cope with Station Blackout for a predetermined amount of time based on design factors for the plant. U.S. regulations define Station Blackout (SBO) as a loss of the offsite electric power system concurrent with turbine trip and unavailability of the onsite emergency AC power system. According to U.S. regulations, typically the coping period for an SBO is 4 hours and can be as long as 16 hours for currently operating BWR plants. Being able to cope with an SBO and loss of all AC power is required by international regulators as well. The U.S. licensing basis for the ESBWR is a coping period of 72 hours for an SBO based on U.S. NRC requirements for passive safety plants. In the event of an extended SBO (viz., greater than 72 hours), the ESBWR response shows that the design is able to cope with the event for at least 7 days without AC electrical power or operator action. ESBWR is a Generation III+ reactor design with an array of passive safety systems. The ESBWR primary success path for mitigation of an SBO event is the Isolation Condenser System (ICS). The ICS is a passive, closed loop, safety system that initiates automatically on a loss of power. Upon Station Blackout or loss of all AC power, the ICS begins removing decay heat from the Reactor Pressure Vessel (RPV) by (i) condensing the steam into water in heat exchangers located in pools of water above the containment, and (ii) transferring the decay heat to the atmosphere. The condensed water is then returned by gravity to cool the reactor again. The ICS alone is capable of maintaining the ESBWR in a safe shutdown condition after an SBO for an extended period. The fuel remains covered throughout the SBO event. The ICS is able to remove decay heat from the RPV for at least 7 days and maintains the reactor in a safe shutdown condition. The water level in the RPV remains well above the top of active fuel for the duration of the SBO event

  19. Emergent transformation games: exploring social innovation agency and activation through the case of the Belgian electricity blackout threat

    Directory of Open Access Journals (Sweden)

    Bonno Pel

    2016-06-01

    Full Text Available The persistence of current societal problems has given rise to a quest for transformative social innovations. As social innovation actors seek to become change makers, it has been suggested that they need to play into impactful macrodevelopments or "game-changers". Here, we aim to deepen the understanding of the social innovation agency in these transformation games. We analyze assumptions about the game metaphor, invoking insights from actor-network theory. The very emergence of transformation games is identified as a crucial but easily overlooked issue. As explored through the recent electricity blackout threat in Belgium, some current transformation games are populated with largely passive players. This illustrative case demonstrates that socially innovative agency cannot be presupposed. In some transformation games, the crucial game-changing effect is to start the game by activating the players.

  20. Numerical analysis on transient characteristics of AP1000 passive residual heat removal system under station blackout accident

    International Nuclear Information System (INIS)

    Based on one-dimensional governing equations, the mathematical models of the reactor primary coolant system and the passive residual heat removal system (PRHRS) were established. A dynamic simulation program PRHRSDSC was developed to analyze the transient characteristics of the system. The program was used to simulate the transient process of PRHRS during station blackout accident. The calculated results were compared with LOFTRAN code. The results show that the core residual heat can be removed efficiently using natural circulation to keep the coolant at sub-cooled state and the peak pressure is below the limit of the operation pressure. The parameter variation trends are well consistent with LOFTRAN code and the rationality of the model is demonstrated. (authors)

  1. Analysis of a Station Black-Out transient in SMR by using the TRACE and RELAP5 code

    Science.gov (United States)

    De Rosa, F.; Lombardo, C.; Mascari, F.; Polidori, M.; Chiovaro, P.; D'Amico, S.; Moscato, I.; Vella, G.

    2014-11-01

    The present paper deals with the investigation of the evolution and consequences of a Station Black-Out (SBO) initiating event transient in the SPES3 facility [1]. This facility is an integral simulator of a small modular reactor being built at the SIET laboratories, in the framework of the R&D program on nuclear fission funded by the Italian Ministry of Economic Development and led by ENEA. The SBO transient will be simulated by using the RELAP5 and TRACE nodalizations of the SPES3 facility. Moreover, the analysis will contribute to study the differences on the code predictions considering the different modelling approach with one and/or three-dimensional components and to compare the capability of these codes to describe the SPES3 facility behaviour.

  2. Station Blackout in unit 1 and analysis of the wind field in the region of Angra dos Reis

    International Nuclear Information System (INIS)

    Highlights: • Severe accident is one that exceeds the design basis (set of information that identifies the specific functions to be performed by an item from a nuclear facility or specific values chosen for controlling parameters as fundamental reference data for the project). • A Station Blackout occurs through loss of external energy and internal energy, consecutively. The external loss by event in the transmission lines. The internal loss by problems in diesel generators. • With a Station Blackout, the Plant begins to present problems at your core, due to failure in the cooling and in the residual heat removal. Without the removal of heat from the fuel rods, the temperature in the core increases abruptly and thus arises a series of events. - Abstract: Since the Fukushima accident a lot wondered on if a nuclear reactor is really safe and, specifically, if the Plants of Angra are trusted to a severe accident as occurred in Japan. The initiator event in Fukushima was a tsunami which in turn affected the external power system and then the internal power system, through failure of the diesel generators. In the case of Angra dos Reis the initiator event would be by sliding slope, the event most likely to occur, which affect the external network, common fault for all three units and later the internal network in this case, the plant most likely fault on your internal network is the unit 1, due the generators GD1 and GD2 have higher probabilities failure of departure and failure to continue to operate 2.86 × 10−2 and 2.4 × 10−3, in comparison with the generators GD3 and CD4, respectively 1.74 × 10−4 and 9.06 × 10−4. With relationship to the dispersibilidade of the pollutant in an eventual liberation for atmosphere, it is inferred by the results of the analysis of the winds of the area that the area presents low capacity dispersive

  3. Can the complex networks help us in the resolution of the problem of power outages (blackouts) in Brazil?

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Paulo Alexandre de; Souza, Thaianne Lopes de [Universidade Federal de Goias (UFG), Catalao, GO (Brazil)

    2011-07-01

    Full text. What the Brazilian soccer championship, Hollywood actors, the network of the Internet, the spread of viruses and electric distribution network have in common? Until less than two decade ago, the answer would be 'nothing' or 'almost nothing'. However, the answer today to this same question is 'all' or 'almost all'. The answer to these questions and more can be found through a sub-area of statistical physics | called science of complex networks that has been used to approach and study the most diverse natural and non-natural systems, such as systems/social networks, information, technological or biological. In this work we study the distribution network of electric power in Brazil (DEEB), from a perspective of complex networks, where we associate stations and/or substations with a network of vertices and the links between the vertices we associate with the transmission lines. We are doing too a comparative study with the best-known models of complex networks, such as Erdoes-Renyi, Configuration Model and Barabasi-Albert, and then we compare with results obtained in real electrical distribution networks. Based on this information, we do a comparative analysis using the following variables: connectivity distribution, diameter, clustering coefficient, which are frequently used in studies of complex networks. We emphasize that the main objective of this study is to analyze the robustness of the network DEEB, and then propose alternatives for network connectivity, which may contribute to the increase of robustness in maintenance projects and/or expansion of the network, in other words our goal is to make the network to proof the blackouts or improve the endurance the network against the blackouts. For this purpose, we use information from the structural properties of networks, computer modeling and simulation. (author)

  4. Assessment of accident management measures on early in-vessel station blackout sequence at VVER-1000 pressurized water reactors

    International Nuclear Information System (INIS)

    Highlights: • Accident management procedures for a station blackout scenario are investigated. • Secondary and primary side countermeasures are compared. • In-depth analyses of the plant behaviour and estimation of time margins. • Insights into the physical phenomena which can influence the passive feeding. • Assessment of the effectiveness of the applied bleed and feed procedures. - Abstract: In the process of elaboration and evaluation of severe accident management guidelines, the assessment of the accident management measures and procedures plays an important role. This paper investigates the early in-vessel phase accident progression of a hypothetical station blackout scenario for a generic VVER-1000 pressurized water reactor. The study focuses on the following accident management measures: primary side depressurization with passive safety systems injection, secondary side depressurization with passive feeding from the feedwater system, and a combination of the both procedures. The analyses have been done with the mechanistic computer code ATHLET. The simulations give in-depth analyses of the reactor system behaviour, assessment of the time margins till heating up of the reactor core and insights into physical phenomena which can influence the passive feeding procedures for cooling of the reactor core. The simulation results show that such accident management measures can significantly prolong the time till core degradation. Maximum delay for core heat up can be achieved by sequentially realization of the secondary and primary side bleed and feed strategies. Due to reversed heat transfer in the steam generators or caused by the depressurization itself a part of the injected water is evaporated. Evaporation or flashing in the feedwater system can lead to an intermittent water injection, thus reducing the effectiveness of the feeding procedure

  5. Assessment of accident management measures on early in-vessel station blackout sequence at VVER-1000 pressurized water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Tusheva, P., E-mail: p.tusheva@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Resource Ecology, Reactor Safety Division, POB 51 01 19, 01314 Dresden (Germany); Schäfer, F., E-mail: f.schaefer@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Resource Ecology, Reactor Safety Division, POB 51 01 19, 01314 Dresden (Germany); Reinke, N., E-mail: nils.reinke@grs.de [Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH, Schwertnergasse 1, 50667 Cologne (Germany); Kamenov, Al., E-mail: alkamenov@npp.bg [Kozloduy NPP Plc., 3321 Kozloduy (Bulgaria); Mladenov, I., E-mail: ivanmladenov@abv.bg [Kozloduy NPP Plc., 3321 Kozloduy (Bulgaria); Kamenov, K., E-mail: k_kamenov@npp.bg [Kozloduy NPP Plc., 3321 Kozloduy (Bulgaria); Kliem, S., E-mail: s.kliem@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Resource Ecology, Reactor Safety Division, POB 51 01 19, 01314 Dresden (Germany)

    2014-10-01

    Highlights: • Accident management procedures for a station blackout scenario are investigated. • Secondary and primary side countermeasures are compared. • In-depth analyses of the plant behaviour and estimation of time margins. • Insights into the physical phenomena which can influence the passive feeding. • Assessment of the effectiveness of the applied bleed and feed procedures. - Abstract: In the process of elaboration and evaluation of severe accident management guidelines, the assessment of the accident management measures and procedures plays an important role. This paper investigates the early in-vessel phase accident progression of a hypothetical station blackout scenario for a generic VVER-1000 pressurized water reactor. The study focuses on the following accident management measures: primary side depressurization with passive safety systems injection, secondary side depressurization with passive feeding from the feedwater system, and a combination of the both procedures. The analyses have been done with the mechanistic computer code ATHLET. The simulations give in-depth analyses of the reactor system behaviour, assessment of the time margins till heating up of the reactor core and insights into physical phenomena which can influence the passive feeding procedures for cooling of the reactor core. The simulation results show that such accident management measures can significantly prolong the time till core degradation. Maximum delay for core heat up can be achieved by sequentially realization of the secondary and primary side bleed and feed strategies. Due to reversed heat transfer in the steam generators or caused by the depressurization itself a part of the injected water is evaporated. Evaporation or flashing in the feedwater system can lead to an intermittent water injection, thus reducing the effectiveness of the feeding procedure.

  6. Containment failure time and mode for a low-pressure short-term station blackout in a BWR-4 with Mark-I containment

    International Nuclear Information System (INIS)

    This study investigates containment failure time and mode for a low-pressure, short-term station blackout severe accident sequence in a boiling water reactor (BWR-4) with a Mark-I containment. The severe accident analysis code MELCOR, version 1.8.1, was used in these calculations. Other results using the MELCOR/CORBH package and the BWRSAR and CONTAIN codes are also presented and compared to the MELCOR results. The plant analyzed is the Peach Bottom atomic station, a BWR-4 with a Mark-I containment. The automatic depressurization system was used to depressurize the vessel in accordance with the Emergency Procedure Guidelines. Two different variations of the station blackout were studied: one with a dry cavity and the other with a flooded cavity. For the flooded cavity, it is assumed that a control rod drive (CRD) pump becomes operational after vessel failure, and it is used to pump water into the cavity

  7. Technical justification of the time period to bring Rivne NPP spent fuel pools into a safe state in case of NPP blackout

    International Nuclear Information System (INIS)

    The main objective of the paper is to examine on the Rivne NPP spent fuel pools using the thermal-hydraulic MELCOR code.A series of calculations with decay heats of spent fuel in case of plant blackout was performed. The departure from nucleate boiling for the spent fuel pools was calculated, which will allow plant personnel to take specific measures on accident management taking into account the available time

  8. Application of RELAP/SCDAPSIM to the analysis of station blackout transient with LBLOCA for VVER-1000

    International Nuclear Information System (INIS)

    This paper shows the results from a transient station blackout with LBLOCA (ID=300 mm) Using different flow models during the in-vessel phase of a severe accident. The default flow model in RELAP5/MOD3.3 is Henry-Fauske, while the flow model in RELAP/SCDAPSIM is the Ransom-Trapp choking model. The aim of this research is to compare the results and validate the RELAP/SCDAPSIM code. RELAP/SCDAPSIM is designed to describe the overall reactor coolant system (RCS) thermal hydraulic response and core behaviour under normal operating conditions or under design basis or severe accident conditions. The SCDAP portion of the code includes models to treat the later stages of a severe accident including debris and molten pool formation, debris/vessel interactions and the structural failure (creep rupture) of vessel structures. The reference power plant for this analysis is a VVER-1000/V320 Kozloduy NPP unit 6. The baseline input deck used in this study for this reactor was developed by the Institute for Nuclear Research and Nuclear Energy. (authors)

  9. Analysis of fuel handling system for fuel bundle safety during station blackout in 500 MWe PHWR unit of India

    International Nuclear Information System (INIS)

    Situations of Station Blackout (SBO) i.e. postulated concurrent unavailability of Class Ill and Class IV power, could arise for a long period, while on-power refuelling or other fuel handling operations are in progress with the hot irradiated fuel bundles being anywhere in the system from the Reactor Building to the Spent Fuel Storage Bay. The cooling provisions for these fuel bundles are diverse and specific to the various stages of fuel handling operations and are either on Class Ill or on Class II power with particular requirements of instrument air. Therefore, during SBO, due to the limited availability of Class II power and instrument air, it becomes difficult to maintain cooling to these fuel bundles. However, some minimal cooling is essential, to ensure the safety of the bundles. As discussed in the paper, safety of these fuel bundles in the system and/or for those lying in the liner tube region of the reactor end fitting is ensured, during SBO, by resorting to passive means like 'stay-put', 'gravity- fill', 'D20- steaming' etc. for cooling the bundles. The paper also describes various consequences emanating from these cooling schemes. (author). 6 refs., 2 tabs., 8 figs

  10. Long-Term Station Blackout Accident Analyses of a PWR with RELAP5/MOD3.3

    Directory of Open Access Journals (Sweden)

    Andrej Prošek

    2013-01-01

    Full Text Available Stress tests performed in Europe after accident at Fukushima Daiichi also required evaluation of the consequences of loss of safety functions due to station blackout (SBO. Long-term SBO in a pressurized water reactor (PWR leads to severe accident sequences, assuming that existing plant means (systems, equipment, and procedures are used for accident mitigation. Therefore the main objective was to study the accident management strategies for SBO scenarios (with different reactor coolant pumps (RCPs leaks assumed to delay the time before core uncovers and significantly heats up. The most important strategies assumed were primary side depressurization and additional makeup water to reactor coolant system (RCS. For simulations of long term SBO scenarios, including early stages of severe accident sequences, the best estimate RELAP5/MOD3.3 and the verified input model of Krško two-loop PWR were used. The results suggest that for the expected magnitude of RCPs seal leak, the core uncovery during the first seven days could be prevented by using the turbine-driven auxiliary feedwater pump and manually depressurizing the RCS through the secondary side. For larger RCPs seal leaks, in general this is not the case. Nevertheless, the core uncovery can be significantly delayed by increasing RCS depressurization.

  11. Analysis of the FeCrAl Accident Tolerant Fuel Concept Benefits during BWR Station Blackout Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Robb, Kevin R [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    Iron-chromium-aluminum (FeCrAl) alloys are being considered for fuel concepts with enhanced accident tolerance. FeCrAl alloys have very slow oxidation kinetics and good strength at high temperatures. FeCrAl could be used for fuel cladding in light water reactors and/or as channel box material in boiling water reactors (BWRs). To estimate the potential safety gains afforded by the FeCrAl concept, the MELCOR code was used to analyze a range of postulated station blackout severe accident scenarios in a BWR/4 reactor employing FeCrAl. The simulations utilize the most recently known thermophysical properties and oxidation kinetics for FeCrAl. Overall, when compared to the traditional Zircaloy-based cladding and channel box, the FeCrAl concept provides a few extra hours of time for operators to take mitigating actions and/or for evacuations to take place. A coolable core geometry is retained longer, enhancing the ability to stabilize an accident. Finally, due to the slower oxidation kinetics, substantially less hydrogen is generated, and the generation is delayed in time. This decreases the amount of non-condensable gases in containment and the potential for deflagrations to inhibit the accident response.

  12. Core structure heat-up and material relocation in a BWR short-term station blackout accident

    International Nuclear Information System (INIS)

    This paper presents an analytical and numerical analysis which evaluates the core-structure heat-up and subsequent relocation of molten core materials during a NWR short-term station blackout accident with ADS. A simplified one-dimensional approach coupled with bounding arguments is first presented to establish an estimate of the temperature differences within a BWR assembly at the point when structural material first begins to melt. This analysis leads to the conclusions that the control blade will be the first structure to melt and that at this point in time, overall temperature differences across the canister-blade region will not be more than 200 K. Next, a three-dimensional heat-transfer model of the canister-blade region within the core is presented that uses a diffusion approximation for the radiation heat transfer. This is compared to the one-dimensional analysis to establish its compatibility. Finally, the extension of the three-dimensional model to include melt relocation using a porous media type approximation is described. The results of this analysis suggest that under these conditions significant amounts of material will relocate to the core plate region and refreeze, potentially forming a significant blockage. The results also indicate that a large amount of lateral spreading of the melted blade and canister material into the fuel rod regions will occur during the melt progression process. 22 refs., 18 figs., 1 tab

  13. Severe accident analyses of a BWR with MAAP5 code. Station blackout and large-break LOCA

    International Nuclear Information System (INIS)

    Calculations were performed for a station blackout (TBU) sequence and a large-break loss-of-coolant accident (AE) sequence of a typical BWR-5 plant with modified Mark-II type containment by the MAAP5 code. The core damage process, both within the reactor vessel before it fails and in the containment afterwards, and the resultant impact on the containment including hydrogen production were investigated. Sensitivity analyses focusing on direct contact heating (DCH) and zirconium oxidation, which affect on the consequences of severe accidents, were also performed. If extensive DCH does not occur in the TBU sequence, failure of the containment vessel can be postponed. On the other hand, concrete ablation at a floor and a side wall in the pedestal due to molten core - concrete interaction (MCCI) significantly increases, because a large amount of debris with high temperature stays inside the pedestal. Although the hydrogen production is affected by the zirconium oxidation model, the differences of hydrogen production are within ± 10% in the case of TBU sequence. (author)

  14. A portable backup power supply to assure extended decay heat removal during natural phenomena-induced station blackout

    International Nuclear Information System (INIS)

    The High Flux Isotope Reactor (HFIR) is a light water cooled and moderated flux-trap type research reactor located at Oak Ridge National Laboratory (ORNL). Coolant circulation following reactor shutdown is provided by the primary coolant pumps. DC-powered pony motors drive these pumps at a reduced flow rate following shutdown of the normal ac-powered motors. Forced circulation decay heat removal is required for several hours to preclude core damage following shutdown. Recent analyses identified a potential vulnerability due to a natural phenomena-induced station blackout. Neither the offsire power supply nor the onsite emergency diesel generators are designed to withstand the effects of seismic events or tornadoes. It could not be assured that the capacity of the dedicated batteries provided as a backup power supply for the primary coolant pump pony motors is adequate to provide forced circulation cooling for the required time following such events. A portable backup power supply added to the plant to address this potential vulnerability is described

  15. Developing Fully Coupled Dynamical Reactor Core Isolation System Models in RELAP-7 for Extended Station Black-Out Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Haihua Zhao; Ling Zou; Hongbin Zhang; David Andrs; Richard Martineau

    2014-04-01

    The reactor core isolation cooling (RCIC) system in a boiling water reactor (BWR) provides makeup water to the reactor vessel for core cooling when the main steam lines are isolated and the normal supply of water to the reactor vessel is lost. It was one of the very few safety systems still available during the Fukushima Daiichi accidents after the tsunamis hit the plants and the system successfully delayed the core meltdown for a few days for unit 2 & 3. Therefore, detailed models for RCIC system components are indispensable to understand extended station black-out accidents (SBO) for BWRs. As part of the effort to develop the new generation reactor system safety analysis code RELAP-7, major components to simulate the RCIC system have been developed. This paper describes the models for those components such as turbine, pump, and wet well. Selected individual component test simulations and a simplified SBO simulation up to but before core damage is presented. The successful implementation of the simplified RCIC and wet well models paves the way to further improve the models for safety analysis by including more detailed physical processes in the near future.

  16. Assessment of the potential for high-pressure melt ejection resulting from a Surry station blackout transient

    International Nuclear Information System (INIS)

    Containment integrity could be challenged by direct heating associated with a high pressure melt ejection (HPME) of core materials following reactor vessel breach during certain severe accidents. Intentional reactor coolant system (RCS) depressurization, where operators latch pressurizer relief valves open, has been proposed as an accident management strategy to reduce risks by mitigating the severity of HPME. However, decay heat levels, valve capacities, and other plant-specific characteristics determine whether the required operator action will be effective. Without operator action, natural circulation flows could heat ex-vessel RCS pressure boundaries (surge line and hot leg piping, steam generator tubes, etc.) to the point of failure before vessel breach, providing an alternate mechanism for RCS depressurization and HPME mitigation. This report contains an assessment of the potential for HPME during a Surry station blackout transient without operator action and without recovery. The assessment included a detailed transient analysis using the SCDAP/RELAP5/MOD3 computer code to calculate the plant response with and without hot leg countercurrent natural circulation, with and without reactor coolant pump seal leakage, and with variations on selected core damage progression parameters. RCS depressurization-related probabilities were also evaluated, primarily based on the code results

  17. Ppercase(melcor) sensitivity studies for a low-pressure, short-term station blackout at the Peach Bottom plant

    International Nuclear Information System (INIS)

    This paper summarizes the results of analyses performed to assess the effect of a variety of design parameters and operational procedures on a station blackout severe accident at the Peach Bottom Atomic Power Station. The severe-accident ppercase(melcor) code, version 1.8.1 was used in these analyses. The following sensitivity studies were completed: effect of the automatic depressurization system actuation timing on the accident progression; effect of fuel and cladding porosities on vessel failure and containment failure times; effect of several parameters on the amount of in-vessel steel ejected into the cavity after vessel failure; effect of different parameters on vessel penetration failure time; vessel failure timing; and lower plenum shroud and core shroud temperatures. These sensitivity studies provided valuable insights into the ppercase(melcor) code behavior and into the progression of this severe accident. The most significant results are: (a) the optimum steam cooling of the core is accomplished when the automatic depressurization system is actuated when the core water level is at one-third of the active core height, delaying vessel failure by minutes and containment failure by hours, (b) vessel failure is significantly delayed (by 2 h) when lower-plenum debris quenching is included in the model, and (c) the core shroud melts during this transient. ((orig.))

  18. The safety assessment of OPR-1000 nuclear power plant for station blackout accident applying the combined deterministic and probabilistic procedure

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dong Gu, E-mail: littlewing@kins.re.kr [Korea Institute of Nuclear Safety, 62 Gwahak-ro, Yuseong-gu, Daejeon 305-338 (Korea, Republic of); Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Chang, Soon Heung [Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2014-08-15

    Highlights: • The combined deterministic and probabilistic procedure (CDPP) was proposed for safety assessment of the BDBAs. • The safety assessment of OPR-1000 nuclear power plant for SBO accident is performed by applying the CDPP. • By estimating the offsite power restoration time appropriately, the SBO risk is reevaluated. • It is concluded that the CDPP is applicable to safety assessment of BDBAs without significant erosion of the safety margin. - Abstract: Station blackout (SBO) is a typical beyond design basis accident (BDBA) and significant contributor to overall plant risk. The risk analysis of SBO could be important basis of rulemaking, accident mitigation strategy, etc. Recently, studies on the integrated approach of deterministic and probabilistic method for nuclear safety in nuclear power plants have been done, and among them, the combined deterministic and probabilistic procedure (CDPP) was proposed for safety assessment of the BDBAs. In the CDPP, the conditional exceedance probability obtained by the best estimate plus uncertainty method acts as go-between deterministic and probabilistic safety assessments, resulting in more reliable values of core damage frequency and conditional core damage probability. In this study, the safety assessment of OPR-1000 nuclear power plant for SBO accident was performed by applying the CDPP. It was confirmed that the SBO risk should be reevaluated by eliminating excessive conservatism in existing probabilistic safety assessment to meet the targeted core damage frequency and conditional core damage probability. By estimating the offsite power restoration time appropriately, the SBO risk was reevaluated, and it was finally confirmed that current OPR-1000 system lies in the acceptable risk against the SBO. In addition, it is concluded that the CDPP is applicable to safety assessment of BDBAs in nuclear power plants without significant erosion of the safety margin.

  19. The safety assessment of OPR-1000 nuclear power plant for station blackout accident applying the combined deterministic and probabilistic procedure

    International Nuclear Information System (INIS)

    Highlights: • The combined deterministic and probabilistic procedure (CDPP) was proposed for safety assessment of the BDBAs. • The safety assessment of OPR-1000 nuclear power plant for SBO accident is performed by applying the CDPP. • By estimating the offsite power restoration time appropriately, the SBO risk is reevaluated. • It is concluded that the CDPP is applicable to safety assessment of BDBAs without significant erosion of the safety margin. - Abstract: Station blackout (SBO) is a typical beyond design basis accident (BDBA) and significant contributor to overall plant risk. The risk analysis of SBO could be important basis of rulemaking, accident mitigation strategy, etc. Recently, studies on the integrated approach of deterministic and probabilistic method for nuclear safety in nuclear power plants have been done, and among them, the combined deterministic and probabilistic procedure (CDPP) was proposed for safety assessment of the BDBAs. In the CDPP, the conditional exceedance probability obtained by the best estimate plus uncertainty method acts as go-between deterministic and probabilistic safety assessments, resulting in more reliable values of core damage frequency and conditional core damage probability. In this study, the safety assessment of OPR-1000 nuclear power plant for SBO accident was performed by applying the CDPP. It was confirmed that the SBO risk should be reevaluated by eliminating excessive conservatism in existing probabilistic safety assessment to meet the targeted core damage frequency and conditional core damage probability. By estimating the offsite power restoration time appropriately, the SBO risk was reevaluated, and it was finally confirmed that current OPR-1000 system lies in the acceptable risk against the SBO. In addition, it is concluded that the CDPP is applicable to safety assessment of BDBAs in nuclear power plants without significant erosion of the safety margin

  20. 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

    OpenAIRE

    Avinash J. Gaikwad; Vijayan, P. K.; Sharad Bhartya; Kannan Iyer; Rajesh Kumar; A. D. Contractor; Lele, H. G.; Vhora, S. F.; A. K. Maurya; Ghosh, A K; H. S. Kushwaha

    2008-01-01

    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 b...

  1. Relap5 Analysis of Processes in Reactor Cooling Circuit andReactor Cavity in Case of Station Blackout in RBMK-1500

    OpenAIRE

    Algirdas Kaliatka; Eugenijus Uspuras; Sigitas Rimkevicius

    2007-01-01

    Ignalina NPP is equipped with channel-type boiling-water graphite-moderated reactor RBMK-1500. Results of the level-1 probabilistic safety assessment of the Ignalina NPP have shown that in topography of the risk, the transients with failure of long-term core cooling other than LOCA are the main contributors to the core damage frequency. The total loss of off-site power with a failure to start any diesel generator, that is station blackout, is the event which could lead to the loss of long-ter...

  2. OPTIMUM STEADY STATE LOAD SHEDDING USING SHUFFLED FROG LEAPING ALGORITHM TO AVERT BLACKOUT IN POWER SYSTEMS DURING OVERLOAD AND GENERATION CONTINGENCIES

    Directory of Open Access Journals (Sweden)

    R. MAGESHVARAN

    2015-10-01

    Full Text Available During generation and overload contingencies in a power system, the system voltage and frequency will decline due to the deficiency of real and reactive powers. Consequently cascaded failures may occur which will lead to complete blackout of certain parts of the power system. Load shedding is considered as the ultimate step of emergency control action that is necessary to prevent a blackout in the power system. This paper proposes a memetic meta-heuristic algorithm known as shuffled frog leaping algorithm (SFLA to find a solution for the steady state load shedding problem presented here. The optimum steady state load shedding problem uses squares of the difference between the connected active and the reactive load and the supplied active and reactive power. The supplied active and reactive powers are treated as dependent variables modeled as functions of bus voltages only. The proposed algorithm is tested on IEEE 14 and 30 bus test systems. The viability of the proposed method is established by comparison with the other conventional methods presented earlier in terms of solution quality and convergence properties.

  3. Blackout! Are you prepared?

    Science.gov (United States)

    Freedman, T J; Gerring, G

    1992-01-01

    Mount Sinai Hospital in Toronto, Ontario, found itself stranded without electrical power for one hour when a transformer blew up in an Ontario Hydro station and hospital emergency generators failed due to inadequate ventilation. This article discusses the impact of the power loss in a facility that relies on sophisticated technology and equipment. Because the article describes the actions that were taken following the incident and presents the audit that has been developed, it may be used by other facilities to assess preparedness and develop improvement plans. PMID:10119474

  4. Thermal-hydraulic analysis of NSSS and containment response during extended station blackout for Maanshan PWR plant

    International Nuclear Information System (INIS)

    Highlights: • Calculate NSSS and containment transient response during extended SBO of 24 h. • RELAP5-3D and GOTHIC models are developed for Maanshan PWR plant. • Reactor coolant pump seal leakage is specifically modeled for each loop. • Analyses are performed with and without secondary-side depressurization, respectively. • Considering different total available time for turbine driven auxiliary feedwater system. - Abstract: A thermal-hydraulic analysis has been performed with respect to the response of the nuclear steam supply system (NSSS) and the containment during an extended station blackout (SBO) duration of 24 h in Maanshan PWR plant. Maanshan plant is a Westinghouse three-loop PWR design with rated core thermal power of 2822 MWt. The analyses in the NSSS and the containment are based on the RELAP5-3D and GOTHIC models, respectively. Important design features of the plant in response to SBO are considered in the respective models, e.g., the steam generator PORVs, turbine driven auxiliary feedwater system (TDAFWS), accumulators, reactor coolant pump (RCP) seal design, various heat structures in the containment, etc. In the analysis it is assumed that the shaft seal in each RCP failed due to loss of seal cooling and the RCS fluid flows to the containment directly. Some parameters calculated from the RELPA5-3D model are input to the containment GOTHIC model, including the RCS average temperature and the RCP seal leakage flow and enthalpy. The RCS average temperature is used to drive the sensible heat transfer to the containment. It is found that the severity of the event depends mainly on whether the secondary side is depressurized or not. If the secondary side is depressurized in time (within 1 h after SBO) and the TDAFWS is available greater than 19 h, then the reactor core will be covered with water throughout the SBO duration, which ensures the integrity of the reactor core. On the contrary, if the secondary side is not depressurized, then the RCS

  5. Thermal-hydraulic analysis of NSSS and containment response during extended station blackout for Maanshan PWR plant

    Energy Technology Data Exchange (ETDEWEB)

    Yuann, Yng-Ruey, E-mail: ryyuann@iner.gov.tw; Hsu, Keng-Hsien, E-mail: hardlycampus@iner.gov.tw; Lin, Chin-Tsu, E-mail: jtling@iner.gov.tw

    2015-07-15

    Highlights: • Calculate NSSS and containment transient response during extended SBO of 24 h. • RELAP5-3D and GOTHIC models are developed for Maanshan PWR plant. • Reactor coolant pump seal leakage is specifically modeled for each loop. • Analyses are performed with and without secondary-side depressurization, respectively. • Considering different total available time for turbine driven auxiliary feedwater system. - Abstract: A thermal-hydraulic analysis has been performed with respect to the response of the nuclear steam supply system (NSSS) and the containment during an extended station blackout (SBO) duration of 24 h in Maanshan PWR plant. Maanshan plant is a Westinghouse three-loop PWR design with rated core thermal power of 2822 MWt. The analyses in the NSSS and the containment are based on the RELAP5-3D and GOTHIC models, respectively. Important design features of the plant in response to SBO are considered in the respective models, e.g., the steam generator PORVs, turbine driven auxiliary feedwater system (TDAFWS), accumulators, reactor coolant pump (RCP) seal design, various heat structures in the containment, etc. In the analysis it is assumed that the shaft seal in each RCP failed due to loss of seal cooling and the RCS fluid flows to the containment directly. Some parameters calculated from the RELPA5-3D model are input to the containment GOTHIC model, including the RCS average temperature and the RCP seal leakage flow and enthalpy. The RCS average temperature is used to drive the sensible heat transfer to the containment. It is found that the severity of the event depends mainly on whether the secondary side is depressurized or not. If the secondary side is depressurized in time (within 1 h after SBO) and the TDAFWS is available greater than 19 h, then the reactor core will be covered with water throughout the SBO duration, which ensures the integrity of the reactor core. On the contrary, if the secondary side is not depressurized, then the RCS

  6. Business interruption impacts of a terrorist attack on the electric power system of Los Angeles: customer resilience to a total blackout.

    Science.gov (United States)

    Rose, Adam; Oladosu, Gbadebo; Liao, Shu-Yi

    2007-06-01

    Regional economies are highly dependent on electricity, thus making their power supply systems attractive terrorist targets. We estimate the largest category of economic losses from electricity outages-business interruption-in the context of a total blackout of electricity in Los Angeles. We advance the state of the art in the estimation of the two factors that strongly influence the losses: indirect effects and resilience. The results indicate that indirect effects in the context of general equilibrium analysis are moderate in size. The stronger factor, and one that pushes in the opposite direction, is resilience. Our analysis indicates that electricity customers have the ability to mute the potential shock to their business operations by as much as 86%. Moreover, market resilience lowers the losses, in part through the dampening of general equilibrium effects. PMID:17640205

  7. Source term analysis in severe accident induced by large break loss of coolant accident coincident with ship blackout for ship reactor

    International Nuclear Information System (INIS)

    Using MELCOR code, the accident analysis model was established for a ship reactor. The behaviors of radioactive fission products were analyzed in the case of severe accident induced by large break loss of coolant accident coincident with ship blackout. The research mainly focused on the behaviors of release, transport, retention and the final distribution of inert gas and CsI. The results show that 83.12% of inert gas releases from the core, and the most of inert gas exists in the containment. About 83.08% of CsI release from the core, 72.66% of which is detained in the debris and the primary system, and 27.34% releases into the containment. The results can give a reference for the evaluation of cabin dose and nuclear emergency management. (authors)

  8. Lightning rod ionizing natural ionca - Ionic electrode active trimetallictriac of grounding - Definitive and total solution against 'blackouts' and electrical faults generated by atmospheric charges (lightning)

    Energy Technology Data Exchange (ETDEWEB)

    Cabareda, Luis

    2010-09-15

    The Natural Ionizing System of Electrical Protection conformed by: Lightning Rod Ionizing Natural Ionca and Ionic Electrode Active Trimetallic Triac of Grounding offers Total Protection, Maximum Security and Zero Risk to Clinics, Hospitals, Integral Diagnostic Center, avoiding ''the burning'' of Electronics Cards; Refineries, Tanks and Stations of Fuel Provision; Electrical Substations, Towers and Transmission Lines with transformer protection, motors, elevators, A/C, mechanicals stairs, portable and cooling equipment, electrical plants, others. This New High Technology is the solution to the paradigm of Benjamin Franklin and it's the mechanism to end the 'Blackouts' that produces so many damages and losses throughout the world.

  9. 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

    Directory of Open Access Journals (Sweden)

    Avinash J. Gaikwad

    2008-01-01

    Full Text Available 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.

  10. Study of the VVER-1000 behaviour during LBLOCA with ID 850 mm combined with station blackout using computer code MELCOR 2.1

    International Nuclear Information System (INIS)

    The purpose of this study is to analyse the key phenomena and processes during the transient “Station blackout (SBO) with large break loss of coolant accident (LBLOCA) with ID =850 mm”. It has been analysed the processes, which show the accident progression since the beginning of LBLOCA in the cold leg to a rupture of the reactor vessel, including the total core uncover, core heating up, hydrogen generation and fusion products release in the primary circuit after rupture of the fuel cladding, melting of the fuel and reactor core internals, and its further relocation to the bottom of the reactor vessel. For the presented analysis, it has been developing a new model for the reactor VVER-1000 with the computer code MELCOR 2.1 for severe accident. The reference nuclear power plant in this study is Kozloduy NPP, units 5 and 6. It has been compared the older version on the computer code MELCOR 1.8.5 with the new version of the code as using the same initial and boundary conditions. The difference in the development of the accident is determined mainly by differences in the models that have been recently developed and added to the MELCOR 2.1 version. Keywords: nuclear safety, severe accident, release of hydrogen, core degradation

  11. RELAP5/MOD2 analysis of a postulated ''cold leg SBLOCA'' simultaneous to a ''total black-out'' event in the Jose Cabrera Nuclear Station

    International Nuclear Information System (INIS)

    Several beyond-design bases cold leg small-break LOCA postulated scenarios based on the ''lessons learned'' in the OECD-LOFT LP-SB-3 experiment have been analyzed for the Westinghouse single loop Jose Cabrera Nuclear Power Plant belonging to the Spanish utility UNION ELECTRICA FENOSA, S.A. The analysis has been done by the utility in the Thermal-Hydraulic ampersand Accident Analysis Section of the Engineering Department of the Nuclear Division. The RELAP5/MOD2/36.04 code has been used on a CYBER 180/830 computer and the simulation includes the 6 in. RHRS charging line, the 2 in. pressurizer spray, and the 1.5 in. CVCS make-up line piping breaks. The assumption of a ''total black-out condition'' coincident with the occurrence of the event has been made in order to consider a plant degraded condition with total active failure of the ECCS. As a result of the analysis, estimates of the ''time to core overheating startup'' as well as an evaluation of alternate operator measures to mitigate the consequences of the event have been obtained. Finally a proposal for improving the LOCA emergency operating procedure (E-1) has been suggested

  12. RELAP5/MOD2 analysis of a postulated ``cold leg SBLOCA`` simultaneous to a ``total black-out`` event in the Jose Cabrera Nuclear Station

    Energy Technology Data Exchange (ETDEWEB)

    Rebollo, L. [Union Electrica, SA, Madrid (Spain)

    1992-04-01

    Several beyond-design bases cold leg small-break LOCA postulated scenarios based on the ``lessons learned`` in the OECD-LOFT LP-SB-3 experiment have been analyzed for the Westinghouse single loop Jose Cabrera Nuclear Power Plant belonging to the Spanish utility UNION ELECTRICA FENOSA, S.A. The analysis has been done by the utility in the Thermal-Hydraulic & Accident Analysis Section of the Engineering Department of the Nuclear Division. The RELAP5/MOD2/36.04 code has been used on a CYBER 180/830 computer and the simulation includes the 6 in. RHRS charging line, the 2 in. pressurizer spray, and the 1.5 in. CVCS make-up line piping breaks. The assumption of a ``total black-out condition`` coincident with the occurrence of the event has been made in order to consider a plant degraded condition with total active failure of the ECCS. As a result of the analysis, estimates of the ``time to core overheating startup`` as well as an evaluation of alternate operator measures to mitigate the consequences of the event have been obtained. Finally a proposal for improving the LOCA emergency operating procedure (E-1) has been suggested.

  13. CPR1000全厂断电事故瞬态特性分析%Transient Analyses of Station Blackout Accident for CPR1000

    Institute of Scientific and Technical Information of China (English)

    张亚培; 田文喜; 秋穗正; 苏光辉

    2011-01-01

    The primary loop of CPR1000 nuclear power plant was modeled using RELAP5/MOD3. 4 code, and the transient thermal hydraulic characteristics were analyzed under the condition of station blackout accident (SBO). The calculation results by RELAP5 code were compared with those of THEMIS code, and the results by RELAP5 code were consistent with those of THEMIS code. The results show that the RELAP5 model can accurately simulate the transient thermal hydraulic characteristics of CPR1000 under the condition of SBO.%用RELAP5/MOD3.4程序对CPR1000压水堆一回路系统进行整体建模,分析全厂断电事故下一回路主要参数的瞬态热工水力特性,并将RELAP5模型计算结果与THEMIS程序的计算结果进行对比,二者符合得较好.计算结果表明:该模型可较准确地模拟CPR1000在事故下的热工水力特性.

  14. Study of the VVER-1000 behaviour during LBLOCA with ID 850 mm combined with station blackout using computer code MELCOR 2.1

    International Nuclear Information System (INIS)

    The purpose of this study is to analyse the key phenomena and processes during the transient “Station blackout (SBO) with large break loss of coolant accident (LBLOCA) with ID =850 mm”. It has been analysed the processes, which show the accident progression since the beginning of LBLOCA in the cold leg to a rupture of the reactor vessel, including the total core uncover, core heating up, hydrogen generation and fusion products release in the primary circuit after rupture of the fuel cladding, melting of the fuel and reactor core internals, and its further relocation to the bottom of the reactor vessel. For the presented analysis, it has been developing a new model for the reactor VVER-1000 with the computer code MELCOR 2.1 for severe accident. The reference nuclear power plant in this study is Kozloduy NPP, units 5 and 6. It has been compared the older version on the computer code MELCOR 1.8.5 with the new version of the code as using the same initial and boundary conditions. The difference in the development of the accident is determined mainly by differences in the models that have been recently developed and added to the MELCOR 2.1 version.

  15. Comparison and analysis on two kinds of passive residual heat removal system designs under blackout accident for integral small modular reactor

    International Nuclear Information System (INIS)

    Small Modular Reactor (SMR) with an electric power less than 300MWe has gained much attention in recent years. By incorporating the safety-by-design and passive concept into the design process, SMRs have made a progress in meeting the safety demand of nuclear energy. There are many similar design features among integral pressurized water SMRs, and the differences are mainly on the design of PRHRS (Passive Residual Heat Removal System). To get a comprehensive understanding of the PRHRS design in SMRs, two simplified simulation models of integral SMR with different PRHRS design are built by the use of thermal hydraulic system code Relap5/Mod3.2 in this paper. A blackout accident is introduced to study the different performance between two PRHRS design models. The calculation results show that both two cases can successfully remove decay heat from the core, and could keep reactor safe for an elegant of time. But there are still some differences between two cases in aspects of primary and PRHRS coolant parameters. Comparisons of the results from two cases are conducted in this paper, and the differences are carefully analyzed too. The major finding is that in the primary side PRHRS design model, primary system parameters have an obvious turbulence at the early stage of accident. (author)

  16. Decay Heat and Dryout Behavior of Spent Fuel Storage Pool with ORIGEN-ARP and MARS codes for the Station Blackout Accident

    International Nuclear Information System (INIS)

    Spent nuclear fuels are stored in spent fuel storage pool (SFP) in nuclear power plants. SFP should be designed and operated to prevent the spent fuels from being critical and have a shielding capability against radiation. Borated water is usually used to prevent the fuel from being critical and provide radiation shielding. Borated water is also used for removal of the decay heat from the spent fuels. Since the fuels may be expected to be fail without cooling, the SFP should be maintained its temperature lower than safety limit. Electric power is always required for the SFP cooling system during all modes of operation to maintain cooling capability of SFP water. In this paper, we performed analysis of decay heat and dryout behavior of spent fuel pool for the station blackout accident (complete loss of AC power). The accident can be regarded as a most challenging one to the SFP and its support system. As a reference, SFP of Ulchin Unit 3 and its state of maximum storage is considered

  17. Risk Assessment for Restoring Units Following Large-scale Blackout%大停电后的机组投运风险评估

    Institute of Scientific and Technical Information of China (English)

    刘艳; 张凡; 顾雪平

    2013-01-01

    大停电后火电机组的安全、有序投运对减小停电损失意义重大。针对面向机组启动的网络重构阶段由机组投运次序不同和运行可靠性导致的可能出现的投运过程不确定情况,首先给出大停电后机组投运风险的定义。在此基础上,引入热备用机组的五状态模型计算已投运机组的停运概率。进一步,以待恢复机组的前导时间划分网架重构时步,基于灵敏度分析求取与不同重构时步对应的可行潮流解,从而获得相应的机组投运容量。最终实现了不同时步下机组投运风险的定量化评估。针对新英格兰10机39节点系统的测试结果表明,该方法对不同重构方案下机组投运风险的比较集中体现了重构恢复效果及其实现的可能性,可为调度人员选择恢复方案提供更加全面的决策辅助信息。%It is important for reducing economic loss to restore the operation of fossil fuel generators in a safe and orderly sequence after a blackout. Due to differences of units’ starting sequence and operational reliability, some uncertain situations may arise at the stage of network reconfiguration. In response to this problem, this paper first proposed the concept of unit’s restoring risk after blackout. Based on the concept, the five-state model of hot-reserve unit was introduced to calculate the failure possibility of units in operation. Further, reconfiguration steps were classified according to the lead time of the unit being ready to start and the feasible power flow, which includes the real power output of units in operation corresponding to each step, was solved by means of the sensitivity analysis. Finally, the quantitative assessment of risk for restoring units was accomplished respecting each reconfiguration step. The outcome of its application on the New England 10-unit 39-bus power system indicates that unit’s restoring risk, manifesting the reconfiguration performance and

  18. Study on containment direct heating probability in station blackout%全厂断电时安全壳直接加热的概率研究

    Institute of Scientific and Technical Information of China (English)

    陈阳丽; 彭常宏; 郭赟

    2016-01-01

    Containment direct heating (DCH)is a potential factor which may cause early failure of containment. In this paper, containment peak pressure and containment failure probability in DCH process are assessed by Risk-Oriented Accident Analysis Methodology (ROAAM)using Two-Cell Equilibrium (TCE)model. The influence of the diameter length of seal-LOCA in Station Blackout (SBO )in reference plant is also analyzed. In ROAAM,probability distribution for Zirconium oxidation fraction and UO2 mass in core debris are sampled to calculate as part of the input data of TCE model. The other part of the input data of the TCE model is given by severe accident analysis program.%安全壳直接加热(DC H )是导致安全壳早期失效的潜在因素,本文应用基于风险导向的事故分析方法(ROAAM),对堆芯碎片中UO2的质量和Zr的氧化份额的概率密度分布抽样,对安全壳直接加热模型TCE(Two-cell Equilibrium)编程,将抽样结果带入TCE模型中计算,得到安全壳压力峰值的累积概率分布和安全壳失效概率,研究压水堆全厂断电始发事故下轴封破口面积不同的情况对下封头失效后安全壳压力峰值的影响。其中TCE模型的输入数据由严重事故分析程序计算给出。

  19. An uncertainty analysis of the hydrogen source term for a station blackout accident in Sequoyah using MELCOR 1.8.5

    Energy Technology Data Exchange (ETDEWEB)

    Gauntt, Randall O.; Bixler, Nathan E.; Wagner, Kenneth Charles.

    2014-03-01

    A methodology for using the MELCOR code with the Latin Hypercube Sampling method was developed to estimate uncertainty in various predicted quantities such as hydrogen generation or release of fission products under severe accident conditions. In this case, the emphasis was on estimating the range of hydrogen sources in station blackout conditions in the Sequoyah Ice Condenser plant, taking into account uncertainties in the modeled physics known to affect hydrogen generation. The method uses user-specified likelihood distributions for uncertain model parameters, which may include uncertainties of a stochastic nature, to produce a collection of code calculations, or realizations, characterizing the range of possible outcomes. Forty MELCOR code realizations of Sequoyah were conducted that included 10 uncertain parameters, producing a range of in-vessel hydrogen quantities. The range of total hydrogen produced was approximately 583kg 131kg. Sensitivity analyses revealed expected trends with respected to the parameters of greatest importance, however, considerable scatter in results when plotted against any of the uncertain parameters was observed, with no parameter manifesting dominant effects on hydrogen generation. It is concluded that, with respect to the physics parameters investigated, in order to further reduce predicted hydrogen uncertainty, it would be necessary to reduce all physics parameter uncertainties similarly, bearing in mind that some parameters are inherently uncertain within a range. It is suspected that some residual uncertainty associated with modeling complex, coupled and synergistic phenomena, is an inherent aspect of complex systems and cannot be reduced to point value estimates. The probabilistic analyses such as the one demonstrated in this work are important to properly characterize response of complex systems such as severe accident progression in nuclear power plants.

  20. Estudio termodinámico y de degradación en un transitorio de Blackout con el código RELAP5/SCDAP de una central genérica de agua en ebullición

    OpenAIRE

    Monset Cabré, Lluís

    2011-01-01

    Esta memoria incluye una primera parte descriptiva del código de cálculo empleado (RELAP5/SCDAP) para la realización de las simulaciones, del tipo de planta nuclear en la que éstas se realizarán (BWR) y del modelo utilizado. Posteriormente se introducirá el escenario estudiado. Es un caso de accidente severo en el que, partiendo del funcionamiento en régimen estacionario de la planta, se iniciará un transitorio de Total Station Blackout. És decir, una pérdida de subministro elé...

  1. 77 FR 16175 - Station Blackout

    Science.gov (United States)

    2012-03-20

    ... relied upon for reactor core decay heat removal and containment heat removal are dependent on ac power... petition for rulemaking (PRM), PRM-50-101 (76 FR 58165) as a way to address SBO mitigation. The approach... Design Criteria for Nuclear Power Plant Construction Permits'' (32 FR 10213). Subsequently, on...

  2. The revelation of India's blackout for China's power industry%印度大停电对我国电力工业的启示

    Institute of Scientific and Technical Information of China (English)

    曾鸣; 李娜; 刘晓立

    2012-01-01

    India's blackout has affected the largest population of world's blackout accidents, which have an important warning for China with similar characteristics in the population and energy distribution. This article first describe the power industry in India from two aspects of electricity supply and demand. At the same time, India's electricity re- form and the current power system characteristics are analyzed, focusing on the power transmission and distribution relationship, scheduling management model and the relationship between ownerships. On this basis, the problems of Indian power industry in grid security, the electricity market construction and power system reform is proposed to guide the development of power industry in China.%印度大停电是世界上受影响人口最多的一次停电事故,这对于在人口和能源分布上特征相似的中国具有重要警示作用。从印度电力供需和电力供应整体格局两方面阐述印度电力工业的基本情况,分析印度电力改革和目前电力体制特点,着重分析印度电力系统的输配关系、调度管理模式和产权关系;在此基础上,提出印度电力工业在电网安全、电力市场建设以及电力体制改革等方面存在的问题,并进一步分析印度大停电对我国电力工业发展的启示。

  3. Analysis of MBLOCA With Blackout Accident of Ship Reactor%船用堆中破口失水加全部电源丧失事故分析

    Institute of Scientific and Technical Information of China (English)

    杨磊; 陈文振; 赵新文; 祁杰

    2012-01-01

    针对船用堆的运行特点,制定了船用堆发生中破口失水叠加全部电源丧失事故时的事故序列,运用RELAP5/MOD3.2程序对某船用堆30%额定功率运行时,一回路主管道上发生30 mm不可隔离的中破口失水叠加全部电源丧失事故进行了分析,并讨论了事故下燃料元件的完整性.结果表明:在发生该类叠加事故后,热阱丧失,反应堆的剩余热将无法导出,堆芯燃料元件会发生大面积破损.研究结果可为运行人员的事故处理和操作提供参考.%According to the operating character of the ship reactor, the medium break loss of coolant accident (MBLOCA) combined with blackout accident was studied. The accident response sequence was established for the combined accident. The 30 mm unsegregated MBLOCA combined with blackout accident was analyzed with RELAP5/ M0D3. 2 code when the reactor operated at 30% rated power. The integrity of fuel elements was also judged. The results indicate that the decay heat of the reactor will not be carried out of the core because of the loss of heat trap under the combined accident, finally all the fuel elements are failed even molten. The research is helpful for the processing of the accident and the establishment of emergency regulations.

  4. 中国实验快堆全厂断电事故多维度热工耦合计算%Multi-dimension Coupled Simulation Method of Thermalhydralic Behavior in China Experimental Fast Reactor Under Blackout Accident

    Institute of Scientific and Technical Information of China (English)

    乔雪冬; 胡文军; 冯预恒; 张春明; 孙微; 赵守智

    2012-01-01

    多维度耦合方法是将传统的一维反应堆热工流体力学程序与三维流体动力学分析软件通过一定的耦合方法结合起来,实现反应堆局部复杂流体现象分析与系统计算的耦合方法.本工作根据中国实验快堆设计和运行经验,开发了基于Rubin和Fluent的耦合程序框架,完成了中国实验快堆全厂断电工况的计算和验证.计算结果表明,耦合方法对全场断电事故的计算结果合理可靠,是对一维系统程序分析方法的有益补充.%Multi-dimension coupled simulation is a method which combines the analysis of complex hydromechanical phenomenon in reactor with system calculation by the method of coupling traditional one-dimensional thermo hydrodynamic program with CFD software. The coupling frame was developed based on Rubin and Fluent codes. By the test calculation under the station blackout accident of China Experimental Fast Reactor (CEFR) , multi-dimension coupled simulation is proved reasonable and gives a efficient supplement to system calculation method.

  5. Severe accident analysis of a representative LWR plant with MAAP5.01 and MELCOR2.1. Comparison of station blackout analysis for a BWR-5/advanced Mark-II containment type plant

    International Nuclear Information System (INIS)

    In order to investigate the differences in characteristics of MAAP5.01 and MELCOR2.1, which are dedicated codes to evaluate severe accident progression, severe accident analyses for a TBU sequence (station blackout with no emergency power supply and no recovery of short- and long-term A/C power) in a BWR-5/advanced Mark-II containment type plant were conducted by using the two codes. Based on the analysis that input settings of the decay heat of fuel, the failure criteria of fuel cladding and core support plate, and zirconium – water interaction model are adjusted between these codes, the hydrodynamic response inside the reactor pressure vessel (RPV) in the early phase (until the onset of fuel relocation) of the TBU sequence is shown to be in good agreement. However, significant differences are observed in the onset timing of the major physical phenomena after the core support plate failure. It is inferred that these disagreements are primarily caused by the differences in characteristics of analytical models in each code, such as debris relocation, coolant channel blockage, entrainment and quench of the molten debris jet in water pool, failure of the RPV lower head, and molten core – concrete interaction (MCCI). (author)

  6. Accident Analysis of Station Blackout of Pool-Type Research Reactor during High Power Operation%池式研究堆高功率全厂断电事故分析

    Institute of Scientific and Technical Information of China (English)

    黄洪文; 刘汉刚; 钱达志; 徐显启

    2012-01-01

    针对全厂断电事故的主要事件序列,采用RETRAN-02程序对某池式研究堆全厂断电事故的进程和关键热工参数进行分析,论证该反应堆对全厂断电事故的承受能力.分析表明,在发生全厂断电事故后,该反应堆能依靠主泵惰转、可靠电源供电的余热排除系统和自然对流方式导出堆芯的剩余发热,防止核安全事故的发生;由可靠电源供电的辅助冷却是缓解该事故的有效措施,其供电能力不小于1h.%Based on the main event sequence, RETRAN-02 code is used to analyze the power supply station blackout accident and key thermal parameters of a pool-type research reactor and demonstrate the enduring capability of the accident. The result proves that the decay heat of the reactor could be removed through the idler wheel rotating, residual heat removal system supported by reliability power, and the natural circulation, which will prevent the nuclear safety accidents. The accessorial cooling supported by reliability power is an effective measure to relieve the accident, and the power can last for an hour at least.

  7. AP1000核电厂应对全厂断电事故的稳压器防满溢对策研究%AP1000 Plant Pressurizer Overfilling Prevention Study Against Station Blackout Accident

    Institute of Scientific and Technical Information of China (English)

    刘展; 王喆; 张国胜; 秦慧敏

    2014-01-01

    If loss of main feed-water occurs in a station blackout accident for AP1000 plant ,the pressurizer will overfill and the coolant will be discharged through pressurizer safety valves .It results in a loss of coolant accident ,RCS inventory will decrease ,and the risk of reactor core uncovering increases .Because of the coolant discharging , the atmosphere radiation level in the containment may be raised , w hile the possibility of radioactive release to the environment increases .In order to prevent pressurizer overfill-ing ,an effective strategy to avoid and mitigate pressurizer overfilling was provided .The results show that increasing heat transfer areas of PRHRS heat exchanger can prevent pressurizer overfilling ;reasonable decreasing of IRWST back pressure can enhance mar-gins of pressurizer overfilling , and mitigate pressurizer overfilling phenomena ;increasing pressurizer volumes can also avoid pressurizer overfilling . T he conclusions have reference value in helping design and safety analysis of AP 1000 plant .%A P1000核电厂若在全厂断电事故下丧失正常给水,会引起稳压器满溢,将通过稳压器安全阀排放液体冷却剂,引起反应堆冷却剂水装量流失,增大反应堆堆芯裸露的风险。与此同时,安全壳内的放射性水平因稳压器满溢可能会增大,增大向环境排放大量放射物质的可能。为防止稳压器满溢,本工作进行了解决或缓解稳压器满溢的对策研究。结果表明,增大非能动余热排出系统(PRHRS )热交换器的传热面积,可防止稳压器满溢;合理降低安全壳内置换料水箱(IRWST )的背压,可增大达到稳压器满溢的裕度,有效地缓解稳压器满溢;增大稳压器的自由容积,可防止稳压器满溢。此结论对A P1000核电厂的设计和事故分析有一定的参考作用。

  8. Thermographic Inspections Save Skins and Prevent Blackouts

    Science.gov (United States)

    2003-01-01

    Scanning thermography involves heating a component s surface and subsequently measuring the surface temperature, using an infrared camera to identify structural defects such as corrosion and disbonding. It is a completely noninvasive and noncontacting process. Scans can detect defects in conventional metals and plastics, as well as in bonded aluminum composites, plastic- and resinbased composites, and laminated structures. The apparatus used for scanning is highly portable and can cover the surface of a test material up to six times faster than conventional thermography. NASA scientists affirm that the technology is an invaluable asset to the airlines, detecting potential defects that can cause structural failure.In 1996, ThermTech Services, Inc., of Stuart, Florida, approached NASA in an effort to evaluate the technology for application in the power and process industries, where corrosion is of serious concern. ThermTech Services proceeded to develop the application for inspecting boiler waterwall tubing at fossil-fueled electric-generating stations. In 1999, ThermTech purchased the rights to NASA s patented technology and developed the specialized equipment required to apply the inspecting method to power plant components. The ThermTech robotic system using NASA technology has proved to be extremely successful and cost effective in performing detailed inspections of large structures such as boiler waterwalls and aboveground chemical storage tanks. It is capable of inspecting a waterwall, tank-wall, or other large surfaces at a rate of approximately 10 square feet per minute or faster.

  9. Blackout: Preventing Racial Discrimination on the Net.

    Science.gov (United States)

    Evans, V. Tessa Perry

    1995-01-01

    Presents issues relating to equality of access to information technology and the Internet for the African American community. Provides suggestions for measures that black information professionals can take to ensure universal access to information and affirmative entrepreneurial opportunities. (JKP)

  10. 用紧急控制降低由输电断面开断引发系统崩溃的风险对印度大停电事故的思考%Application of Emergency Control to Reduce Risk of System Collapse Triggered by Power Transmission Interface Tripping: Thinking on the India Power Blackouts

    Institute of Scientific and Technical Information of China (English)

    方勇杰

    2013-01-01

    简述了2012年7月30日和7月31日在印度发生大停电事故的过程.通过分析2次事故之间造成系统崩溃规模差异的原因,指出:缺乏主动控制措施导致大量潮流跨网转移超出电网转供能力是印度大停电的关键原因,而由输电断面开断事件自动触发集中切机和切负荷控制是防止类似事故发生的最有效的紧急控制措施,并可以从风险的观点来审视其经济上的合理性.从紧急控制技术的视角,总结了为保障控制有效性而需要进一步深化的工作,包括装置判据的研究、动作逻辑与系统响应交互影响的分析、控制效果对电网运行工况的适应性校核、紧急控制措施运行管理的加强等.%This paper presents a simplified description of the event evolution of the India power blackouts on the 30th and 31st of July in 2012.With the analysis of the technical causes leading to the difference in scale of system collapse between the 2 blackouts, it is pointed out that the key cause of both events is the indirect transfer capability exceeded by cross-grid rerouting of large power flow due to lack of active control measures.While the centralized generator tripping and load shedding automatically triggered by the sudden loss event of transmission interface are the most effective emergency control measures for the prevention of similar blackouts, the economic rationality of which can be assessed from the viewpoint of risk reduction.From the perspective of emergency control technology, it is concluded that several fundamental measures need to be strengthened to ensure the effectiveness of the control, including research on fault identification criterion, analysis of mutual influence between control logic and system response, verification of adaptability of control effect to system operating conditions, and tightening up the operational management of emergency control measures.

  11. Study on Failure Principle of Reactor Pressure Vessel in Severe Acident Induced by Station Blackout%全厂断电引发的严重事故中反应堆压力容器失效机理研究

    Institute of Scientific and Technical Information of China (English)

    张龙飞; 房保国; 李凤宇

    2012-01-01

    The reference plant was a typical three-loop PWR of generationII, based on the best estimate computer code RELAP/SCDAPSIM, the failure principle of reactor pressure vessel in severe accident induced by station blackout was analysed. The calculation results show that RELAP/SCDAPSIM program of the COUPLE two-dimensional finite element model can predict the detailed molten material behavior characteristic in pressure vessel, and the lower head failure time and failure position are in good agreement with existing experimental results.%以国际上典型的第2代3环路压水堆核电站为研究对象,采用严重事故最佳估算程序RELAP/SCDAPSIM,对全厂断电引发的严重事故中反应堆压力容器失效机理进行了计算分析.计算结果表明,RELAP/SCDAPSIM程序中的COUPLE二维有限元模型能够详细地预测压力容器内熔融物的行为特性,所给出的下封头失效时间和失效位置与已有实验结果吻合.

  12. Batteries'Usability Study in Station Blackout (SBO) for QinShan Nuclear Power Phase II Extension Project%秦山二期扩建核电厂全厂断电(SBO)事故下蓄电池可用性研究

    Institute of Scientific and Technical Information of China (English)

    游洲; 韩勇; 刘文静; 李朋

    2015-01-01

    Station Blackout (SBO) indicates the all AC power supply lost on the emergency and non-emergency bus in the nuclear power plant. In SBO period, batteries' usability is vital for the nuclear power plant to deal with this fault. This paper introduces the way to use batteries, the calculation and analysis of the power supply time in SBO accident. Some suggestions are given for how to deal with SBO.%全厂断电(SBO)是指核电厂完全丧失应急以及非应急母线上的交流电源。全厂断电后,核电厂蓄电池组的可用性成为整个核电厂应对该事故的关键。对秦山二期扩建工程的蓄电池组在SBO事故下的投用方式进行了介绍,对其带载时间进行了计算和分析,就应对SBO事故提出了建议。

  13. Station Blackout Severe Accident Analysis of Spent Fuel Pool of 600 MWe NPP by Using MELCOR Code%用 MELCOR 程序分析600 MWe 核电厂乏燃料水池失去厂内外电源严重事故

    Institute of Scientific and Technical Information of China (English)

    张应超; 季松涛; 魏严凇; 史晓磊; 许倩

    2016-01-01

    Using MELCOR code ,the spent fuel pool (SFP) of 600 MWe nuclear power plant (NPP) was modeled ,and the station blackout severe accidents were calculated when the SFP was under normal condition ,refuelling condition and the reactor accident condition .The calculation results show that fuel assemblies will melt down and hydro‐gen will generate ,due to zirconium‐water reaction ,after the half height of fuel assem‐blies is uncovered .The influence of injection or spray on SFP accidents was analysed , and the results show that SFP accidents will be terminated and the water level of SFP will return up before fuel cladding damage if water is injected or sprayed into the SFP with the boiling evaporation mass rate .%利用MELCOR程序建立了600 MWe核电厂乏燃料水池计算模型,分别计算了在正常储存、正常换料和反应堆事故工况下,乏燃料水池失去厂内外电源严重事故序列。计算结果表明,燃料组件大约裸露一半后,锆水反应导致燃料熔化并产生大量氢气。分析了喷淋和注水对乏燃料水池事故的影响,分析结果表明,在燃料包壳失效前,以沸腾蒸发速率注水或喷淋能中止事故发展,并能使乏燃料水池水位缓慢回升。

  14. Numerical Analysis on Transient Characteristics of AP1000 Passive Residual Heat Removal System Under Station Blackout Accident%全厂断电事故下 AP1000非能动余热排出系统瞬态特性数值分析

    Institute of Scientific and Technical Information of China (English)

    王宝生; 王冬青; 董化平; 姜晶; 张建民

    2013-01-01

    Based on one-dimensional governing equations , the mathematical models of the reactor primary coolant system and the passive residual heat removal system (PRHRS) were established .A dynamic simulation program PRHRSDSC was developed to analyze the transient characteristics of the system .The program was used to simulate the transient process of PRHRS during station blackout accident .The calculated results were compared with LOFTRAN code .The results show that the core residual heat can be removed efficiently using natural circulation to keep the coolant at sub-cooled state and the peak pressure is below the limit of the operation pressure .T he parameter varia-tion trends are well consistent with LOFTRAN code and the rationality of the model is demonstrated .%在一维质量、动量和能量守恒方程基础上建立了A P1000反应堆主冷却剂系统及非能动余热排出系统数学模型,并编制了用于该系统瞬态特性分析的动态仿真程序PRHRSDSC。模拟了非能动余热排出系统在全厂断电事故下的瞬态响应过程,并将计算结果与西屋公司的 LOFTRAN程序结果进行对比。结果表明:系统可依靠自然循环有效导出堆芯余热,一回路冷却剂温度维持在过冷状态,峰值压力未超过运行压力限值,各参数的变化趋势符合良好,证明了建模的合理性。

  15. Extended Station Blackout Coping Capabilities of APR1400

    OpenAIRE

    Sang-Won Lee; Tae Hyub Hong; Mi-Ro Seo; Young-Seung Lee; Hyeong-Taek Kim

    2014-01-01

    The Fukushima Dai-ichi nuclear power plant accident shows that an extreme natural disaster can prevent the proper restoration of electric power for several days, so-called extended SBO. In Korea, the government and industry performed comprehensive special safety inspections on all domestic nuclear power plants against beyond design bases external events. One of the safety improvement action items related to the extended SBO is installation of external water injection provision and equipment t...

  16. Extended Station Blackout Coping Capabilities of APR1400

    Directory of Open Access Journals (Sweden)

    Sang-Won Lee

    2014-01-01

    Full Text Available The Fukushima Dai-ichi nuclear power plant accident shows that an extreme natural disaster can prevent the proper restoration of electric power for several days, so-called extended SBO. In Korea, the government and industry performed comprehensive special safety inspections on all domestic nuclear power plants against beyond design bases external events. One of the safety improvement action items related to the extended SBO is installation of external water injection provision and equipment to RCS and SG. In this paper, the extended SBO coping capability of APR1400 is examined using MAAP4 to assess the effectiveness of the external water injection strategy. Results show that an external injection into SG is applicable to mitigate an extended SBO scenario. However, an external injection into RCS is only effective when RCS depressurization capacity is sufficiently provided in case of high pressure scenarios. Based on the above results, the technical basis of external injection strategy will be reflected on development of revised severe accident management guideline.

  17. Blackout: coal, climate and the last energy crisis

    Energy Technology Data Exchange (ETDEWEB)

    Heinberg, R. [Post Carbon Institute in California, CA (United States)

    2009-07-15

    Coal fuels more than 30 per cent of UK electricity production, and about 50 per cent in the US, providing a significant portion of total energy output. China and India's recent ferocious economic growth has been based almost entirely on coal-generated electricity. Coal currently looks like a solution to many of our fast-growing energy problems. However, while coal advocates are urging us full steam ahead, the increasing reliance on this dirtiest of all fossil fuels has crucial implications for energy policy, pollution levels, the global climate, world economy and geopolitics. Drawbacks to a coal-based energy strategy include: Scarcity - new studies suggest that the peak of world coal production may actually be less than two decades away; Cost - the quality of produced coal is declining, while the expense of transportation is rising, leading to spiralling costs and increasing shortages; and, Climate impacts - our ability to deal with the historic challenge of climate change may hinge on reducing coal consumption in future years.

  18. Thirty years of blackouts: a case report of swallow syncope

    Directory of Open Access Journals (Sweden)

    Irene Lambiris

    2013-04-01

    Full Text Available Deglutition syncope has been demonstrated in isolated case reports, the first being described over 50 years ago. It is thought to be caused by a hypersensitive vagotonic reflex in response to esophageal dilation after swallowing. It can cause syncope due to complete atrioventricular (AV block and acute reduction of cardiac output. Although rare, its lethality is worthy of discussion, as early recognition can offer complete treatment with placement of a pacemaker. A 54-year-old man presented with 30 years of lightheadedness and syncope, followed by disorientation and tremors, after eating sandwiches or drinking carbonated beverages. He initially was evaluated by a neurologist. Work-up included cardiac 2D transthoracic echocardiogram, electroencephalogram, swallow stud, pulmonary function tests, electrocardiogram, and cardiac stress testing. All tests were within normal limits, and it was determined that he was suffering from convulsive syncope and deglutition syncope. Referral to the cardiac electrophysiology department with tilt-table testing accompanied by swallow evaluation was then recommended. The tests demonstrated marked vagal response resulting in sinus bradycardia with second-degree AV block and pauses up to 3.5 seconds. Patient experienced near syncope. A rate-responsive, dual-chamber Boston Scientific pacemaker with DDDR programming was implanted. Patient has remained asymptomatic at follow-up.

  19. Thirty years of blackouts: a case report of swallow syncope

    OpenAIRE

    Lambiris, Irene; Mendoza, Ivan; Helguera, Marcelo; Baez Escudero, Jose; Bonilla, Cesar

    2013-01-01

    Deglutition syncope has been demonstrated in isolated case reports, the first being described over 50 years ago. It is thought to be caused by a hypersensitive vagotonic reflex in response to esophageal dilation after swallowing. It can cause syncope due to complete atrioventricular (AV) block and acute reduction of cardiac output. Although rare, its lethality is worthy of discussion, as early recognition can offer complete treatment with placement of a pacemaker. A 54-year-old man presented ...

  20. Risk Analysis for Steam Generator Tube Creep Rupture Under Severe Accident Induced by Station Blackout%全厂断电引发的严重事故下蒸汽发生器传热管蠕变失效风险研究

    Institute of Scientific and Technical Information of China (English)

    陈宝文; 毛欢; 孔翔程; 陈彬

    2014-01-01

    全厂断电引发的严重事故若处置不当,可能发展为长期、高压的严重事故进程,此时堆芯冷却系统中的自然循环在导出部分堆芯余热的同时,也增加了蒸汽发生器(S G )传热管、稳压器波动管以及热管段出现蠕变失效的风险。本文基于两环路设计的秦山二期核电厂设计特点,结合蠕变失效风险模型,对全厂断电引发的严重事故后未能执行“严重事故管理导则中向蒸汽发生器注水(SAG-1)”时SG传热管的蠕变失效风险进行了研究,从而为全厂断电引发的严重事故的负面影响提供量化结果,为技术支持中心(T SC )最终决策提供参考依据。分析结果表明,全厂断电引发的严重事故后16361 s可能出现蠕变失效;自事故后16610 s ,SG传热管出现蠕变失效的可能性均远低于稳压器波动管与热管段,秦山二期核电厂全厂断电引发的严重事故下因SG传热管蠕变失效而导致安全壳旁通的风险很小。%T he severe accident induced by station blackout (SBO ) could lead to a long-term and high pressure sequence with inappropriate mitigation and the risk of creep rupture of steam generator (SG ) tubes , pressurizer surge line and hotleg would be significant due to natural circulation inside reactor coolant system .Based on the two-loop design of Qinshan Ⅱ NPP ,together with a probabilistic creep rupture model ,this paper performed detailed evaluation for risk of creep rupture of SG tubes without imple-menting the action of injection water into SG in severe accident management guide (SAMG) (SAG-1) following severe accident induced by SBO .Therefore ,quantitative results of negative impact of severe accident induced by SBO are supported to TSC which is in charge of making the final decision for reference .It is concluded that the risk of creep rupture rises around 16 361 s since SBO . T he risk of SG tube creep rupture is much lower than that of

  1. Tests of Shaft Seal Systems of Circulation Pumps during Station Blackout

    International Nuclear Information System (INIS)

    AREVA GmbH operates a unique Thermal-hydraulic plat form in Germany, France and USA. It is recognised as a test body according to ISO 17025. The Deutsche Akkreditierungsstelle GmbH (DAkkS - German Society for Accreditation) has also certified the Thermal-hydraulic platform as an independent inspection body Type C according to ISO 17020. A part of this platform is the Component Laboratory located in Karlstein, Germany which is in operation since more than 50 years. The testing activities cover a wide range as: Critical Heat Flux Tests, Valve Testing and Environmental Qualification for safety related components. Since 2011 the Component Qualification Karlstein extended their testing scope for different types of Shaft Seal Systems. (Author)

  2. Structure of a scheme of emergency control to avoid blackout due to interconnection lines loss

    Energy Technology Data Exchange (ETDEWEB)

    Luz, L.T. da; Werberich, L.C.; Herve, H.M. [Companhia Estadual de Energia Eletrica do Estado do Rio Grande do Sul (CEEE), Porto Alegre, RS (Brazil)

    1994-12-31

    This work presents the structure of Gravatai Emergency Control Scheme (ECS) with short about its development and operation. This ECS was made to avoid two kinds of problems for the systems of Companhia Estadual de Energia Eletrica (CEEE). The first one is the voltage collapse that happens after the opening of one of the 525 kv LTs of the interconnection with the Brazilian Interconnected System (BIS). The second one is the CEEE isolating after the 525 kV network loss. We show the ECS existence reason and we describe its functional structure, the substations, the circuits and the amount of load shedding involved by the system. Finally, we present the project of a control structure based on microcomputer which is being developed for this ECS. (author) 3 refs., 11 figs.

  3. Modeling of a Flooding Induced Station Blackout for a Pressurized Water Reactor Using the RISMC Toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Mandelli, Diego; Prescott, Steven R; Smith, Curtis L; Alfonsi, Andrea; Rabiti, Cristian; Cogliati, Joshua J; Kinoshita, Robert A

    2011-07-01

    In the Risk Informed Safety Margin Characterization (RISMC) approach we want to understand not just the frequency of an event like core damage, but how close we are (or are not) to key safety-related events and how might we increase our safety margins. The RISMC Pathway uses the probabilistic margin approach to quantify impacts to reliability and safety by coupling both probabilistic (via stochastic simulation) and mechanistic (via physics models) approaches. This coupling takes place through the interchange of physical parameters and operational or accident scenarios. In this paper we apply the RISMC approach to evaluate the impact of a power uprate on a pressurized water reactor (PWR) for a tsunami-induced flooding test case. This analysis is performed using the RISMC toolkit: RELAP-7 and RAVEN codes. RELAP-7 is the new generation of system analysis codes that is responsible for simulating the thermal-hydraulic dynamics of PWR and boiling water reactor systems. RAVEN has two capabilities: to act as a controller of the RELAP-7 simulation (e.g., system activation) and to perform statistical analyses (e.g., run multiple RELAP-7 simulations where sequencing/timing of events have been changed according to a set of stochastic distributions). By using the RISMC toolkit, we can evaluate how power uprate affects the system recovery measures needed to avoid core damage after the PWR lost all available AC power by a tsunami induced flooding. The simulation of the actual flooding is performed by using a smooth particle hydrodynamics code: NEUTRINO.

  4. Blackout control : proposal of a preventive methodology and its implementation in the Portuguese grid

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, M.M.; Perro, L.L.; Rodrigues, A.C.R. [Rede Electrica Nacional (Portugal)

    2007-07-01

    This paper presented simulation results of the behaviour of the Portuguese electric power transmission grid after the non simultaneous tripping of existing and future natural gas combined-cycle power plants for different load profiles. Of the 62 identified main causes of worldwide major power disturbances, 24 were found to be due to natural events such as fires and storms; 20 were due to failure of primary equipment such as circuit breakers; and, 18 were due to incorrect behaviour of protection systems. A disturbance was classified as a major disturbance if the event had a severity greater then 1 system minute, or if the loss of generation was greater than 10 per cent of peak demand. Seven of these major disturbances have been reported by the Portuguese transmission grid. The tripping of big power plants in Portugal was caused by the loss of multiple grid elements during normal operation of the system. Identifying the main causes of major disturbances offers the possibility of establishing a methodology to prevent major disturbances by simulating the behaviour of the power system under an appropriate set of severe contingencies. This paper described the methodology used to choose the more severe contingencies that should be simulated in the Portuguese transmission grid to help prevent major disturbances. 4 refs., 3 tabs., 5 figs.

  5. A Flooding Induced Station Blackout Analysis for a Pressurized Water Reactor Using the RISMC Toolkit

    OpenAIRE

    Diego Mandelli; Steven Prescott; Curtis Smith; Andrea Alfonsi; Cristian Rabiti; Joshua Cogliati; Robert Kinoshita

    2015-01-01

    In this paper we evaluate the impact of a power uprate on a pressurized water reactor (PWR) for a tsunami-induced flooding test case. This analysis is performed using the RISMC toolkit: the RELAP-7 and RAVEN codes. RELAP-7 is the new generation of system analysis codes that is responsible for simulating the thermal-hydraulic dynamics of PWR and boiling water reactor systems. RAVEN has two capabilities: to act as a controller of the RELAP-7 simulation (e.g., component/system activation) and to...

  6. Evaluation of steam generator U-tube integrity during PWR station blackout with secondary system depressurization

    OpenAIRE

    日高 昭秀; 浅香 英明; 上野 信吾; 吉野 丈人; 杉本 純

    1999-01-01

    2次系減圧を伴うPWR電源喪失事故時に炉心が昇温すると、温度上昇に起因して蒸気発生器伝熱管が破損する可能性がある。米国NRCの解析は、その場合でも、サージラインが先に破損することを示したが、沈着したFPからの崩壊熱を考慮していない。そこで、その影響を調べるため、まず、米国NRCの解析で使用したホットレグ水平対向流モデルを原研のLSTF実験で検証した後、Surry炉を対象としてSCDAP/RELAP5コードを用いた解析を行った。FP沈着量と崩壊熱は原研のARTコードを用いて別途計算した。その崩壊熱を熱応答計算で考慮した場合、伝熱管の健全性はかろうじて確保された。しかしながら、種々の不確実性を考慮すると、伝熱管が最初に破損する可能性を排除できない。このことは、2次系減圧に関するアクシデントマネジメント方策の得失を評価するうえで考慮しておく必要がある。...

  7. Depressurization analyses of PWR station blackout with MELCOR 1.8.4

    OpenAIRE

    A.R. Antariksawan; 日高 昭秀; 森山 清史; 橋本 和一郎

    2001-01-01

    PWRの全電源喪失事故(TMLB')では、高圧溶融物放出とそれに続く格納容器直接加熱により格納容器の健全性が脅かされることから、その防止・緩和対策として、一次系強制減圧が推奨されている。また、TMLB'では、一次冷却系ポンプのシール部が冷却不十分のために途中で破損する(ポンプシールLOCA; S3-TMLB')可能性がある。本報では、MELCOR 1.8.4コードを用いて行ったIndian Point 3号炉のTMLB'及びS3-TMLB'とその一次系減圧に関する解析結果について記述する。S3-TMLB'では、ポンプシールの破損タイミングによって事故進展が変化する。TMLB'中に加圧器逃がし弁を開放して減圧した場合の炉心損傷進展は、減圧しない時のそれとほぼ同じとなるが、安全弁も併せて開放すると、事故進展が約6000秒遅れた。...

  8. 17 CFR 245.102 - Exceptions to definition of blackout period.

    Science.gov (United States)

    2010-04-01

    ... corporate merger, acquisition, divestiture or similar transaction involving the plan or plan sponsor, the... able to participate in the same class of equity securities after the merger, acquisition,...

  9. A flooding induced station blackout analysis for a pressurized water reactor using the RISMC toolkit

    International Nuclear Information System (INIS)

    In this paper we evaluate the impact of a power uprate on a pressurized water reactor (PWR) for a tsunami-induced flooding test case. This analysis is performed using the RISMC toolkit: the RELAP-7 and RAVEN codes. RELAP-7 is the new generation of system analysis codes that is responsible for simulating the thermal-hydraulic dynamics of PWR and boiling water reactor systems. RAVEN has two capabilities: to act as a controller of the RELAP-7 simulation (e.g., component/system activation) and to perform statistical analyses. In our case, the simulation of the flooding is performed by using an advanced smooth particle hydrodynamics code called NEUTRINO. The obtained results allow the user to investigate and quantify the impact of timing and sequencing of events on system safety. The impact of power uprate is determined in terms of both core damage probability and safety margins

  10. External Reactor Vessel Cooling Strategy Application for APR1400 Station Blackout Scenarios

    International Nuclear Information System (INIS)

    In Korea, all NPPs implemented post-Fukushima measures. In U. S., the approach is to expand B5b strategy to build up FLEX strategies utilizing portable equipment. With portable pumps and connections, one can mitigate and respond to wide range of accidents. In this study, we examined the feasibility of cavity flooding using portable pumps for ERVC and its effectiveness in responding to extended SBO scenarios. The external reactor vessel cooling (ERVC) is one of important severe accident management (SAM) strategies adopted for APR1400. ERVC strategy is to remove decay heat from molten corium in lower plenum by submerging the vessel with water. The strategy requires water injection into cavity and APR1400 uses shutdown cooling pumps for this purpose, requiring electricity. Recent Fukushima accident shows the importance of mitigation capability against extended SBO scenarios

  11. A Flooding Induced Station Blackout Analysis for a Pressurized Water Reactor Using the RISMC Toolkit

    Directory of Open Access Journals (Sweden)

    Diego Mandelli

    2015-01-01

    Full Text Available In this paper we evaluate the impact of a power uprate on a pressurized water reactor (PWR for a tsunami-induced flooding test case. This analysis is performed using the RISMC toolkit: the RELAP-7 and RAVEN codes. RELAP-7 is the new generation of system analysis codes that is responsible for simulating the thermal-hydraulic dynamics of PWR and boiling water reactor systems. RAVEN has two capabilities: to act as a controller of the RELAP-7 simulation (e.g., component/system activation and to perform statistical analyses. In our case, the simulation of the flooding is performed by using an advanced smooth particle hydrodynamics code called NEUTRINO. The obtained results allow the user to investigate and quantify the impact of timing and sequencing of events on system safety. In addition, the impact of power uprate is determined in terms of both core damage probability and safety margins.

  12. External Reactor Vessel Cooling Strategy Application for APR1400 Station Blackout Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Quang Diep Khanh; Oh, Seung Jong [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of); Ro, Seo Mi [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    In Korea, all NPPs implemented post-Fukushima measures. In U. S., the approach is to expand B5b strategy to build up FLEX strategies utilizing portable equipment. With portable pumps and connections, one can mitigate and respond to wide range of accidents. In this study, we examined the feasibility of cavity flooding using portable pumps for ERVC and its effectiveness in responding to extended SBO scenarios. The external reactor vessel cooling (ERVC) is one of important severe accident management (SAM) strategies adopted for APR1400. ERVC strategy is to remove decay heat from molten corium in lower plenum by submerging the vessel with water. The strategy requires water injection into cavity and APR1400 uses shutdown cooling pumps for this purpose, requiring electricity. Recent Fukushima accident shows the importance of mitigation capability against extended SBO scenarios.

  13. Depressurization as an accident management strategy for Jose Cabrera nuclear plant loss of feedwater and station blackout events

    International Nuclear Information System (INIS)

    This paper reports on an evaluation of the efficiency of the operator initiated depressurization in the Spanish Westinghouse one loop Jose Cabrera nuclear power plant that has been developed. This operation is recommended in the present emergency procedure for the total loss of feedwater event in the bleed and feed mode. RELAP5/MOD2 analyses show that this is an effective measure to bring the plant to a cold and stable condition in a design-based accident scenario

  14. Comparison Study on Thermal-Hydraulic Analysis Depending on Liquid Relief Valve Response for an Station Blackout in CANDU-6

    International Nuclear Information System (INIS)

    The purpose of this analysis is to compare the results of thermal-hydraulic analysis depending on liquid relief valve response during a station black out (SBO) events in CANDU-6. The primary heat transport system (PHTS) behavior following the postulated SBO is analyzed using CATHENA code. In the paper, analysis was performed to evaluate the effect on coolant system where LRVs are assumed to be opened or opened according to normal open characteristics in the condition of SBO. The result showed that the primary pressure boundary is extended from LRV to DCT and the effects on primary system behavior were neglectable

  15. Analysis of a Hypothetical Station Blackout in Kori Nuclear Unit 1 Using the MARS and CUPID codes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Donghyun; Lee, Junyeob; Jeong, Jaejun [Pusan National Univ., Busan (Korea, Republic of); Park, Ikkyu; Bae, Sungwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The objective of this study is to analyze multi-dimensional two-phase flow in the reactor coolant circuit during a station black out (SBO) accident. The accident led to a loss of residual heat removal (RHR) during the SBO period and subsequent 7 min, resulting in the increase of the hot leg temperature up to 58.3 .deg. C from 36.9 .deg. C. In this work, a hypothetical prolonged SBO was analyzed to investigate its potential danger using the MARS and CUPID codes. Using the MARS and CUPID codes, a hypothetical prolonged SBO at the KNU-1 was analyzed to investigate its potential danger. The coolant temperatures in the reactor increased continuously after the SBO accident. However, a boiling in the coolant core did not occur until about 40,000 s. Thereafter, flashing occurs near the free surface above the top of the reactor core. The coolant temperature in the CUPID code analysis was lower than the measured one at 19 min and that of the MARS 3D calculation. It is because of smaller friction factors. However, in general, the results of the two codes were consistent with each other.

  16. Comparison Study on Thermal-Hydraulic Analysis Depending on Liquid Relief Valve Response for an Station Blackout in CANDU-6

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. M.; Kho, D. W. [KHNP-CRI, Daejeon (Korea, Republic of); Choi, S. H.; Moon, B. J.; Kim, S. R. [Nuclear Engineering Service and Solution Co., Daejeon (Korea, Republic of)

    2014-10-15

    The purpose of this analysis is to compare the results of thermal-hydraulic analysis depending on liquid relief valve response during a station black out (SBO) events in CANDU-6. The primary heat transport system (PHTS) behavior following the postulated SBO is analyzed using CATHENA code. In the paper, analysis was performed to evaluate the effect on coolant system where LRVs are assumed to be opened or opened according to normal open characteristics in the condition of SBO. The result showed that the primary pressure boundary is extended from LRV to DCT and the effects on primary system behavior were neglectable.

  17. Severe-accident-sequence assessment of hypothetical complete-station blackout at the Browns Ferry Nuclear Plant

    Energy Technology Data Exchange (ETDEWEB)

    Yue, D.D.; Condon, W.A.

    1981-01-01

    An investigation has been made of various accident sequence which may occur following a complete loss of offsite and onsite ac power at a Boiling Water Reactor nuclear power plant. The investigation was performed for the Browns Ferry Nuclear Power Plant, and all accident sequences resulted in a hypothetical core meltdown. Detailed calculations were performed with the MARCH computer meltdown. Detailed calcuations were performed with the MARCH computer code containing a decay power calculation which was modified to include the actinides. This change has resulted in shortening the time before core uncovery by approx. 18%, and reducing the time before the start of core melting by approx. 26%. Following the hypothetical core meltdown accident, the drywell electric penetration assembly seals have been identified as the most likely leak pathway outside the containment. This potential mode of containment failure occurs at a pressure approx. 30% lower than that analyzed in the Reactor Safety Study.

  18. Preliminary Assessment of the Possible BWR Core/Vessel Damage States for Fukushima Daiichi Station Blackout Scenarios Using RELAP/SCDAPSIM

    OpenAIRE

    C. M. Allison; J. K. Hohorst; B. S. Allison; D. Konjarek; Bajs, T.; R. Pericas; Reventos, F.; Lopez, R.

    2012-01-01

    Immediately after the accident at Fukushima Daiichi, Innovative Systems Software and other members of the international SCDAP Development and Training Program started an assessment of the possible core/vessel damage states of the Fukushima Daiichi Units 1–3. The assessment included a brief review of relevant severe accident experiments and a series of detailed calculations using RELAP/SCDAPSIM. The calculations used a detailed RELAP/SCDAPSIM model of the Laguna Verde BWR vessel and related re...

  19. Analysis of Station Blackout Accident for Subcritical Energy Reactor%次临界能源堆全厂断电事故研究

    Institute of Scientific and Technical Information of China (English)

    张大彬; 解衡; 周志伟

    2015-01-01

    针对次临界能源堆包层燃料结构,修改了MELCOR程序堆芯导热模型,建立次临界能源包层及其冷却回路的严重事故分析模型.在验证了建模方法合理性的基础上,用MELCOR程序开展全厂断电事故导致的严重事故响应特性研究.计算结果表明:包层燃料区功率密度越高,裸露时间越早,燃料熔化越快;内包层上部燃料区域首先出现熔化,外包层熔化时间稍晚,且熔化都发生在所在区域裸露2h以后;锆水反应对事故进程影响明显,部分燃料区域锆水反应释热成为燃料温度持续升高甚至熔化的主要热源.

  20. Analysis of station blackout accident in nuclear power plant%核电厂全厂断电事故分析

    Institute of Scientific and Technical Information of China (English)

    陈学锋

    2011-01-01

    全厂断电(SBO)可能发展成为堆芯熔化、安全壳超压失效的严重事故.本文首先研究全厂断电事故的必要性以及在辅助给水系统不可用情况下的全厂断电事故的进程,随后定性的分析了事故进程在主泵轴封泄漏和对一回路实施减压缓解措施的影响下所具有的不同的发展情况.最后以秦山核电厂为例对其在提高应对全厂断电事故的能力和改进缓解事故后果的措施方面提出了建议.

  1. Station Blackout Accident and Mitigation Measure for PWR-NPP%压水堆核电厂全厂断电事故及其缓解措施

    Institute of Scientific and Technical Information of China (English)

    张龙飞; 张大发; 徐金良

    2008-01-01

    以1座典型的3环路压水堆核电厂为参考对象,分别研究了发生全厂断电事故时堆芯在低压和高压状态下的损坏进程.结果表明:在考虑稳压器波动管的蠕变失效时,虽避免了高压熔堆,但低压状态下堆芯损坏更为严重,且产生更多的氢气.分析了导致这一结果的原因,提出了在堆芯出口温度达923 K时的严重事故缓解措施.计算结果表明:该缓解措施能有效地延缓堆芯损坏进程,为操纵员恢复交流电源以及采取其它缓解手段赢得更多时间.

  2. Análisis de la respuesta estructural del edificio de contención de un reactor nuclear PWR frente a una secuencia de Station Blackout

    OpenAIRE

    Martínez Casanovas, Josep Maria

    2013-01-01

    Después del Accidente que sucedió el 11 de marzo de 2011 en la central nuclear de Daichii-Fukushima, han sido muchos los debates reabiertos acerca de la seguridad que ofrecen los reactores nucleares en operación. Debido a las incertidumbres que este accidente ha suscitado, surge ésta tesina, en la que se pretende conocer y comprender técnicamente que sucedería si un accidente similar al de Fukushima ocurriese en uno de los reactores de nuestro país. Con el principal objetivo de encontrar res...

  3. Analysis of Containment Response During Station Blackout%核电厂全厂断电事故下安全壳响应的计算分析

    Institute of Scientific and Technical Information of China (English)

    袁凯; 黄高峰; 曹学武; 李京喜

    2010-01-01

    利用一体化安全分析程序研究核电厂全厂断电(SBO)事故工况下安全壳的响应.研究表明,SBO事故下安全壳会发生超压失效,如果及时恢复交流(AC)电源,安全壳内的压力和温度会迅速降低,安全壳不会发生超压失效.在压力容器失效前恢复AC电源,压力容器就有可能保持完整性.压力容器破损后,AC电源的恢复将使得安全壳内蒸汽浓度大幅减少,从而相应增加了氢气的浓度,导致氢气风险的增加.

  4. Preliminary Assessment of the Possible BWR Core/Vessel Damage States for Fukushima Daiichi Station Blackout Scenarios Using RELAP/SCDAPSIM

    Directory of Open Access Journals (Sweden)

    C. M. Allison

    2012-01-01

    Full Text Available Immediately after the accident at Fukushima Daiichi, Innovative Systems Software and other members of the international SCDAP Development and Training Program started an assessment of the possible core/vessel damage states of the Fukushima Daiichi Units 1–3. The assessment included a brief review of relevant severe accident experiments and a series of detailed calculations using RELAP/SCDAPSIM. The calculations used a detailed RELAP/SCDAPSIM model of the Laguna Verde BWR vessel and related reactor cooling systems. The Laguna Verde models were provided by the Comision Nacional de Seguridad Nuclear y Salvaguardias, the Mexican nuclear regulatory authority. The initial assessment was originally presented to the International Atomic Energy Agency on March 21 to support their emergency response team and later to our Japanese members to support their Fukushima Daiichi specific analysis and model development.

  5. Preliminary Assessment of the Possible BWR Core/Vessel Damage States for Fukushima Daiichi Station Blackout Scenarios Using RELAP/SCDAPSIM

    International Nuclear Information System (INIS)

    Immediately after the accident at Fukushima Daiichi, Innovative Systems Software and other members of the international SCDAP Development and Training Program started an assessment of the possible core/vessel damage states of the Fukushima Daiichi Units 13. The assessment included a brief review of relevant severe accident experiments and a series of detailed calculations using RELAP/SCDAPSIM. The calculations used a detailed RELAP/SCDAPSIM model of the Laguna Verde BWR vessel and related reactor cooling systems. The Laguna Verde models were provided by the Comision Nacional de Seguridad Nuclear y Salvaguardias, the Mexican nuclear regulatory authority. The initial assessment was originally presented to the International Atomic Energy Agency on March 21 to support their emergency response team and later to our Japanese members to support their Fukushima Daiichi specific analysis and model development.

  6. 10 CFR 50.63 - Loss of all alternating current power.

    Science.gov (United States)

    2010-01-01

    ..., each light-water-cooled nuclear power plant licensed under subpart C of 10 CFR part 52 after the... recover from a station blackout as defined in § 50.2. The specified station blackout duration shall be... containment integrity is maintained in the event of a station blackout for the specified duration....

  7. 77 FR 70484 - Preoperational Testing of Onsite Electric Power Systems To Verify Proper Load Group Assignments...

    Science.gov (United States)

    2012-11-26

    ... encompass preoperational testing of electrical power systems used to meet current Station Blackout... all alternating current power (Station Blackout) and loss of large areas of the plant due to... regulatory requirements addressing Station Blackout and loss of large areas of the plant due to explosions...

  8. 10 CFR 50.2 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... in a timely manner after the onset of station blackout; and (4) Has sufficient capacity and reliability for operation of all systems required for coping with station blackout and for the time required... accident (non-DBA)) for station blackout means bringing the plant to those shutdown conditions specified...

  9. Failure analysis on China power grid based on power law

    Institute of Scientific and Technical Information of China (English)

    Xiaofeng WENG; Yiguang HONG; Ancheng XUE; Shengwei MEI

    2006-01-01

    This paper is concerned with the mechanism of blackouts in China power system from the viewpoint of self-organized criticality. By using two estimation algorithms of scaled window variance (SWV) and rescaled rangestatistics (R/S), this paper studies the blackout data in China power system during 1988-1997. The result of analysis shows that the blackout data of 1994-1997 coincides well with the autocorrelation. Furthermore, it is found that the function of blackout probability vs. blackout size exhibits power law distribution.

  10. CANDU堆核电厂全厂断电始发严重事故进程研究%Severe Accident Progression Analysis Induced by Station Blackout for CANDU Station

    Institute of Scientific and Technical Information of China (English)

    佟立丽; 曹学武; 袁凯; 黄高峰

    2010-01-01

    采用一体化分析程序建立了适用于CANDU堆核电厂的严重事故分析模型.该模型主要包括热传输系统、慢化剂系统、端屏蔽系统、蒸汽发生器二次侧系统等.针对全厂断电始发的严重事故进行了相应的热工水力现象分析,得知慢化剂系统和端屏蔽系统内的大量水使事故进程大幅推迟.同时,对重要时间进程与ISAAC2 0程序结果进行了初步比对,两者的结果基本吻合.分析结果可为开展重水堆严重事故现象及缓解措施研究提供技术参考.

  11. Accident Analysis of Station Blackout for China Advanced Research Reactor with Shutdown Failure%中国先进研究堆未能停堆的全厂断电事故分析

    Institute of Scientific and Technical Information of China (English)

    田文喜; 秋穗正; 苏光辉; 贾斗南; 张建伟

    2008-01-01

    针对中国先进研究堆(CARR)的具体结构和运行特点,考虑冷却剂所有可能的流动状态以及换热形式,利用FORTRAN程序设计语言开发了CARR瞬态热工水力计算程序TSACC.利用程序对CARR发生全厂断电事故(SBO)时控制棒不能下落,且应急冷却泵不能投入运行这一严重事故工况进行了计算分析.计算结果表明:CARR发生SBO时,在应急冷却系统故障和控制棒不能插入堆芯的严重事故工况下,堆芯功率仍然能够在冷却剂密度反馈、空泡反馈及燃料多普勒反馈等作用下降低至较低的水平,能够保证燃料元件结构的完整性,也说明了CARR具有很高的固有安全性.计算结果同时发现:在自然循环建立过程中,堆芯冷却剂流量出现了短暂的密度波流动不稳定现象.

  12. Test Study on Safety Features of Station Blackout Accident for Nuclear Main Pump%断电事故对核主泵安全特性影响的试验研究

    Institute of Scientific and Technical Information of China (English)

    刘夏杰; 刘军生; 王德忠; 杨哲; 张继革

    2009-01-01

    介绍了国内外反应堆冷却剂泵在发生各种事故情况下的理论及试验研究情况,针对核主泵断电惰转过程中的瞬态水力特性进行了试验研究,对试验结果进行了讨论.介绍了用于断电试验的试验设备及试验方法,着重分析了惰转过程中流量、转速、振动参数,并用四次多项式拟合的方法模拟惰转过程的流量、转速随时间的变化.试验结果表明:在断电瞬间,泵的流量和转速迅速下降,试验结果符合安全标准规定;轴承座位移振动在断电瞬间突然加强,在断电后一段时间转轴振动才发生变化.试验和分析结果有助于认识核主泵发生全厂断电事故时的水力特性,为核主泵的安全评价提供基础依据.

  13. Analysis of Natural Circulation and Creep Damage under Station Blackout Severe Accidents%全厂断电严重事故自然循环和蠕变失效分析

    Institute of Scientific and Technical Information of China (English)

    向清安; 邓纯锐; 陈宝文; 冯进军

    2014-01-01

    使用MELCOR 2.1程序建立ACP1000自然循环模型,选取全厂断电叠加辅助给水丧失严重事故(TMLB'),分析主冷却剂管道热段和蒸汽发生器(SG)传热管自然循环现象,采用蠕变失效模型评价主冷却剂系统(RCS)部件失效时间.结果表明,压力容器(RPV)出口接管比有裂纹的SG最热传热管先失效.

  14. Analysis of Off-Site Consequence in Case of Station Blackout Accident for Qinshan Nuclear Power Plant%秦山核电厂全厂断电事故厂外后果分析

    Institute of Scientific and Technical Information of China (English)

    樊申; 谢建伦; 张应超

    2006-01-01

    采用MELCOR和MACCS程序对秦山核电厂全厂断电事故的源项和厂外后果进行计算.该事故将引起厂外群体受到较大剂量的放射性照射,但辐照剂量不足以引发早期确定性健康效应.对可能采取的应急防护行动进行评估,确定最佳防护措施为:安全壳泄漏阶段实施隐蔽;若安全壳超压失效无法避免,应急计划区内应立即实施撤离.

  15. 中国实验快堆堆容器冷却系统全厂断电工况温度场分析%Thermal Hydro-Mechanical Analysis of Reactor Vessel Cooling System under Station Blackout Accident

    Institute of Scientific and Technical Information of China (English)

    乔雪冬; 杨红义; 冯预恒

    2006-01-01

    堆容器冷却系统是中国实验快堆(CEFR)-回路系统中的重要辅助系统之一,用于在各种工况下对反应堆堆容器进行冷却.本文利用国际通用的计算流体力学软件STAR-CD对CEFR堆容器冷却系统进行三维数值模拟,得到了在全厂断电事故发展过程中堆容器冷却系统的温度场和流场的瞬态分析结果,为相应部件的力学分析以及其它工况的分析提供了数据,对快堆优化设计和安全分析提供了重要的理论支持.

  16. Estudio termodinámico y estructural de un escenario transitorio de Blackout en la planta nuclear de Ascó II con el código RELAP5/SCDAP

    OpenAIRE

    Weill , Vincent

    2005-01-01

    Esta memoria incluye una primera parte descriptiva del modelo de planta de Ascó II, modelo híbrido realizado utilizando el código de cálculo RELAP5/SCDAP. El término híbrido significa que se trata de dos aspectos del diseño de la planta nuclear: la descripción de la vasija con su nodalización específica SCDAP y la descripción de la parte hidrodinámica, es decir de todos los otros componentes, con una nodalización RELAP. Una vez el modelo descrito, se introducirá el escenario es...

  17. 韶关电网一次停电事故分析及其技术改造优化方案研究%An analysis of blackout of Shaoguan power grid and research on technical reconstruction optimization scheme

    Institute of Scientific and Technical Information of China (English)

    柳玉波; 甄卫国; 余涛

    2011-01-01

    The optimal configuration of busbar automatic transfer switch (BATS) plays an important role in improving the reliability of power supply in a regional power grid.Taking the outage of Mojiang in Shaoguan power grid as an example, the operating characteristics of the power grid before and after the outage and the cause of the accident are analyzed by using BPA transient stability analysis program.The optimization scheme for improving the reliability of power supply in power grid is analyzed.Action logic and control strategy for BATS of the Mojiang station are designed.The dynamic simulation results show that the proposed scheme is feasible, which can make the power grid recover rapidly under the same fault in different operation modes, and make voltage and frequency recover to the acceptable operating range.The proposed scheme can effectively improve the reliability of power supply.%变电站备自投装置的优化配置对于一个地区电网的供电可靠性的提高作用显著.以韶关电网墨江片一起停电事故为例,应用BPA暂态稳定分析程序,分析了事故前后电网的运行特点及失电原因,研究了提高变电站供电可靠性的优化方案,针对该站的特殊情况设计备自投装置的动作逻辑和控制策略.动态仿真分析结果显示,所提方案使电网在同样事故条件,在不同运行方式下均能有效快速恢复片区供电,电压及频率恢复稳定至正常运行范围内,提高了电网的供电可靠性,方案可行.

  18. Core safety discussion under station blackout ATWS accident of solid fuel molten salt reactor%固态熔盐堆全厂断电ATWS事故工况下的堆芯安全探讨

    Institute of Scientific and Technical Information of China (English)

    焦小伟; 王凯; 何兆忠; 陈堃

    2015-01-01

    利用修改后的适用于固态熔盐堆的RELAP5/MOD4.0系统分析程序,对固态熔盐堆全厂断电ATWS(Anticipated Transient Without Scram)事故进行了分析.主回路系统进行了合理简化建模,模拟系统在全厂断电ATWS事故时非能动余热排出系统有效与否两种情况下的瞬态响应过程.分析结果表明:非能动余热排出系统在全厂断电ATWS事故初期作用不明显,但长期作用较明显,投入使用后最终将使堆芯温度和主冷却剂温度达到稳定;对于固态熔盐堆来说,即使非能动余热排出系统失效,燃料元件温度上升也很缓慢,给人员干预采取必要措施提供了超过20天的宽限时间.分析结果表明了固态熔盐堆在应对极端事件时具有高的安全性.

  19. 秦山Ⅰ期核电厂全厂断电事故源项研究%Study on Source Terms in Station Blackout Accident of Qinshan-Ⅰ Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    樊申; 张应超; 季松涛

    2006-01-01

    利用MELCOR程序分析秦山Ⅰ期核电厂全厂断电事故进程中放射性裂变产物的行为,研究不同性质的裂变产物各自的释放、迁移和最终分布状况.同时计算了向环境释放的源项.这些数据可用于事故的厂外后果评价.

  20. Calculation of Fission Product Behaviour in a Station Blackout Accident of Daya Bay Nuclear Power Plant%大亚湾核电厂全厂"断电"事故裂变产物行为计算

    Institute of Scientific and Technical Information of China (English)

    郎明刚; 高祖瑛; 周志伟; 奚树人

    2002-01-01

    使用 MELCOR 程序模拟大亚湾核电厂假想全厂断电事故早期进程,计算出安全壳内源项的最大存量,同KORIGEN 程序结合推导出安全壳内主要裂变产物的活性,为核电厂PSA 分析提供保守性数据.

  1. Salvia miltiorrhiza Bunge Blocks Ethanol-Induced Synaptic Dysfunction through Regulation of NMDA Receptor-Dependent Synaptic Transmission

    OpenAIRE

    Park, Hye Jin; Lee, Seungheon; Jung, Ji Wook; Lee, Young Choon; Choi, Seong-Min; Kim, Dong hyun

    2016-01-01

    Consumption of high doses of ethanol can lead to amnesia, which often manifests as a blackout. These blackouts experienced by ethanol consumers may be a major cause of the social problems associated with excess ethanol consumption. However, there is currently no established treatment for preventing these ethanol-induced blackouts. In this study, we tested the ethanol extract of the roots of Salvia miltiorrhiza (SM) for its ability to mitigate ethanol-induced behavioral and synaptic deficits. ...

  2. Prospects of Studies on Application of Complex System Theory in Power Systems

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Over the last decade, power systems in the world have suffered a number of blackouts caused by cascading failures. Such incidents resulted in major economic losses and social impacts, induced great concerns on the grid security and prompted people to understand and analyze the mechanism of the power system's cascading failures and blackouts. Conventional analysis on power systems constructs a detailed model of every component of the system, and focuses on dynamic behaviors of individual components. Therefore, it is difficult to uncover the global dynamic characteristic while deeply studying the cascading failures and the mechanism of large blackouts. The complex system theory can provide global perspectives of cascading blackouts.

  3. Electricity grid: When the lights go out

    Science.gov (United States)

    Dobson, Ian

    2016-05-01

    The resilience of distribution power grids is put to the test by daily operations as well as by extreme weather events such as hurricanes. An analysis of blackout data in upstate New York now reveals that larger blackouts have a disproportionate effect on grid reliability.

  4. 78 FR 32279 - Advisory Committee On Reactor Safeguards; Notice of Meeting

    Science.gov (United States)

    2013-05-29

    ... conduct of the meeting. 8:35 a.m.-10:00 a.m.: Station Blackout Mitigation Strategies Rulemaking (Open... regarding the draft regulatory basis for the Station Blackout Mitigation Strategies rulemaking. 10:15 a.m... October 18, 2012, (76 FR 64146-64147). In accordance with those procedures, oral or written views may...

  5. 47 CFR 76.130 - Substitutions.

    Science.gov (United States)

    2010-10-01

    ... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout..., syndicated program exclusivity, or sports blackout rules, a satellite carrier is required to delete a... station for which the satellite carrier has obtained the necessary legal rights and permissions,...

  6. 77 FR 64935 - Reliability Standards for Geomagnetic Disturbances

    Science.gov (United States)

    2012-10-24

    ... Prevention and Mitigation of Station Blackout, filed in Docket No. AD12-13-000, at 13 (May 4, 2012) (citing... Homeland Security at 2 (citing 1989 Hydro-Qu bec blackout); Statement of Frank Koza, PJM Interconnection, L... instability and subsequent voltage collapse,'' and cites as an example the 1989 Hydro- Qu bec...

  7. Local Effects of Delayed Food

    Science.gov (United States)

    Davison, Michael; Baum, William M.

    2007-01-01

    Five pigeons were trained on a procedure in which seven concurrent variable-interval schedules arranged seven different food-rate ratios in random sequence in each session. Each of these components lasted for 10 response-produced food deliveries, and components were separated by 10-s blackouts. We varied delays to food (signaled by blackout)…

  8. Development of Early Warning Methods for Electric Power Systems

    DEFF Research Database (Denmark)

    Jóhannsson, Hjörtur

    This thesis concerns the development of methods that can provide, in realtime, an early warning for an emerging blackout in electric power systems. The blackout in E-Denmark and S-Sweden on September 23, 2003 is the main motivation for the method development. The blackout was caused by occurrence...... develop methods, that could, in such situations, give an early warning for the emerging blackout. After investigation of data and plots taken from the time of the blackout, it was decided to focus the development on assessment of aperiodic small signal stability. In order to assess the system generators......-snapshot of the system conditions as an input and determined the injection and Thevenin system impedances I for all system generators. A test bench software was written for the purpose of testing the developed algorithm. A large scale test of the assessment method was carried out where a simulation of the...

  9. 秦山核电厂小破口失水加全厂断电事故序列的堆芯早期破坏过程分析%Analysis of Early Degradation of Qinshan Nuclear Power Plant--A Sequence of SBLOCA With Station Blackout

    Institute of Scientific and Technical Information of China (English)

    季松涛; 张应超

    2000-01-01

    建立了秦山核电厂ICARE2 V2mod2.3程序计算模型,分析了小破口失水加全厂断电事故的堆芯早期失效过程.分析结果表明:堆芯从4 560 s开始破坏.由于堆芯的冷却条件很差,使得整个的堆芯早期失效过程相对较快.ICARE2程序对早期破坏过程分析的有效时间只持续了约7900s.

  10. CPR1000核电厂应对超设计基准全厂断电增设移动电源的研究与设计%Research and Design of Mobile Electricity Generators Added for CPR1000 NPP Station Blackout

    Institute of Scientific and Technical Information of China (English)

    张淑兴; 曹宇

    2014-01-01

    福岛核事故的经验反馈表明,超设计基准的长时间全厂断电可能发生,核电厂有必要增设移动电源.本文从CPR1000核电厂的电源配置出发,结合福岛核事故经验反馈,讨论极端自然灾害带来的全厂断电风险,分析确定增设移动电源的必要性及其功能定位.针对全厂断电工况下必须保持供电的负荷进行研究,以确定移动电源的合理功率.分析介绍目前移动式应急电源的分类以及优缺点,并根据核电厂应用的具体需求,选择合适的电源类型,最后,指出核电厂移动电源设计的关键要素并给出相关的设计建议.

  11. 国内二代改进型核电机组应对双机组全厂断电事故的可行性分析%The Feasibility Analysis of the Response Measures to Double-unit Station Blackout Accident in Generation H Plus PWR Nuclear Power Plants

    Institute of Scientific and Technical Information of China (English)

    杨鹏; 郭新海; 赵丹妮

    2014-01-01

    核电厂双机组共用问题是在日本福岛核事故后的重要经验反馈.而双机组同时发生全厂断电事故是国内二代改进型(M310)核电厂面临的重要共性问题之一.本文对M310型核电厂在发生全厂断电事故后的处理策略和用水压试验泵应对全厂断电事故的能力进行了分析,并对水压试验泵应对双机组同时发生全厂断电事故时存在的问题及可行的解决方案进行了讨论.

  12. 大亚湾核电站全厂断电事故及第5台应急柴油机的概率安全评价%Probabilistic Safety Assessment of Station Blackout Accident and 5th Emergency Diesel in Daya Bay NPP

    Institute of Scientific and Technical Information of China (English)

    王朝贵; 郭建兵

    2004-01-01

    对大亚湾核电站全厂断电事故(SBO)及第5台应急柴油机改进项目进行了概率安全评价(PSA),给出了电源不可恢复因子的计算方法,并对第5台应急柴油机的接入时间进行了敏感性分析.研究结果表明,全厂断电引起的堆芯损坏频率(CDF)较大,增加第5台柴油机对降低堆芯损伤风险有明显的好处,而该台柴油机接入时间的长短对降低堆芯损坏频率有较大影响.

  13. 全厂断电事故时TACR-1000非能动慢化剂余热排出系统排热能力研究%Research on Heat Removal Capability for Passive Moderator Residual Heat Removal System of TACR-1000 when Station Black-Out Accident

    Institute of Scientific and Technical Information of China (English)

    闫林; 贾宝山; 廉海波

    2008-01-01

    为了评估非能动慢化剂余热排出系统的有效性,本文采用CATHENA程序模拟了正常工况及冷却水流失事故工况下非能动慢化剂余热排出系统的排热能力.通过对慢化剂冷却系统的模拟计算得到稳态运行结果,将该结果作为瞬态分析的初始条件计算了非能动慢化剂余热排出系统的排热能力,对计算结果进行了分析.分析结果表明,非能动慢化剂余热排出系统能够保证反应堆安全.

  14. The Influence of Magnetic Field on Antenna Performance in Plasma

    International Nuclear Information System (INIS)

    A spacecraft loses all forms of communication, including global positioning system signals, data telemetry, voice communication and so on, when it enters the communication blackout phase. This becomes more and more critical with the development of reentry vehicle missions since radio blackout brings about many serious issues related to vehicle safety. This paper studies the influence of magnetic field on antenna performance in plasma. The results indicate that the effect of plasma on the antenna performance can be negligible when the magnetic field reaches a certain strength. This provides another way to solve the reentry blackout problem

  15. Plaadid / Tui Hirv

    Index Scriptorium Estoniae

    Hirv, Tui, 1984-

    2007-01-01

    Uutest heliplaatidest Andrea Bocelli "Vivere. The Best Of", Britney Spears "Blackout", John Fogerty "Revival", Bat For Lashes "Fur And Gold", Jimmy Eat World "Chase This Light", Duran Duran "Red Carpet Massacre"

  16. 47 CFR 76.124 - Requirements for invocation of protection.

    Science.gov (United States)

    2010-10-01

    ... Exclusivity and Sports Blackout § 76.124 Requirements for invocation of protection. For a television broadcast station licensee or distributor of syndicated programming to be eligible to invoke the provisions of §...

  17. 77 FR 64563 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Regulatory...

    Science.gov (United States)

    2012-10-22

    ... efforts to develop a revision to the Station Blackout Rule. The Subcommittee will hear presentations by... participation in ACRS meetings were published in the Federal Register on October 17, 2011, (76 FR...

  18. 78 FR 63516 - Initial Test Program of Emergency Core Cooling Systems for New Boiling-Water Reactors

    Science.gov (United States)

    2013-10-24

    ...) System, which support functions for alternate water injection during station blackout. ] II. Additional..., was published in the Federal Register on June 15, 2012 (77 FR 36014), for a 60-day public...

  19. 47 CFR 76.110 - Substitutions.

    Science.gov (United States)

    2010-10-01

    ... blackout rules at § 76.111, substitute a program from any other television broadcast station. Programs... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports...

  20. 76 FR 3887 - Notice of Public Information Collection(s) Being Submitted for Review and Approval to the Office...

    Science.gov (United States)

    2011-01-21

    ... an organization to demonstrate that a particular broadcast station is eligible for significantly... Protection; 47 CFR 76.127, Satellite Sports Blackout Rules. Form Number: Not applicable. Type of...

  1. 77 FR 65419 - Virginia Electric and Power Company

    Science.gov (United States)

    2012-10-26

    ... and 2, to a prolonged station blackout. (11) The current emergency evacuation plans for North Anna 1... Power Station, Units 1 and 2 (North Anna 1 and 2), by the Virginia Electric and Power Company (VEPCO...

  2. 47 CFR 76.106 - Exceptions.

    Science.gov (United States)

    2010-10-01

    ... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout... Commission, and serve a copy of that notice on every television station that would be entitled to...

  3. 76 FR 23341 - Sunshine Federal Register Notice

    Science.gov (United States)

    2011-04-26

    ..., 2011 9:30 a.m. Briefing on the Status of NRC Response to Events in Japan and Briefing on Station Blackout (Public Meeting); (Contact: George Wilson, 301-415-1711) This meeting will be webcast live at...

  4. 77 FR 68160 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Regulatory...

    Science.gov (United States)

    2012-11-15

    ... develop a revision to the Station Blackout Rule. The Subcommittee will hear presentations by and hold... ACRS meetings were published in the Federal Register on October 18, 2012, (77 FR 64146-64147)....

  5. 47 CFR 76.103 - Parties entitled to syndicated exclusivity.

    Science.gov (United States)

    2010-10-01

    ... Exclusivity and Sports Blackout § 76.103 Parties entitled to syndicated exclusivity. (a) Television broadcast station licensees shall be entitled to exercise exclusivity rights pursuant to § 76.101 in accordance...

  6. Women and Diabetes

    Medline Plus

    Full Text Available ... tips to help you manage your diabetes. Food Safety for People with Diabetes Your Glucose Meter - easy- ... to Store your Insulin during Storms and Blackouts Safety Information for Diabetes Medicines and Devices Beware of ...

  7. Důsledky velkých výpadků elektrické energie na zemědělské chovy Jihočeského kraje

    OpenAIRE

    PARLÁSKOVÁ, Lucie

    2013-01-01

    Electrical energy plays an indispensable role in our contemporary society. However, we mostly realize its position in agriculture in a situation which often already entails irreversible consequences. Therefore, the thesis aims to assess the consequences of power blackout on agricultural farming. In connection with the selected objective, a question arises whether long-term power blackouts also constitute a serious threat to agricultural farms of South Bohemia? The theoretical part briefly des...

  8. Electromagnetic Wave Propagation In The Plasma Layer of A Reentry Vehicle

    CERN Document Server

    Kundrapu, Madhusudhan; Beckwith, Kris; Stoltz, Peter; Shashurin, Alexey; Keidar, Michael

    2014-01-01

    The ability to simulate a reentry vehicle plasma layer and the radio wave interaction with that layer, is crucial to the design of aerospace vehicles when the analysis of radio communication blackout is required. Results of aerothermal heating, plasma generation and electromagnetic wave propagation over a reentry vehicle are presented in this paper. Simulation of a magnetic window radio communication blackout mitigation method is successfully demonstrated.

  9. Integration of wind power for optimal power system black-start restoration

    OpenAIRE

    ZONKOLY, AMANY EL

    2015-01-01

    Integration of wind farms into power systems may increase the risk of power system blackouts due to the uncertain nature of their output power. In the meantime, wind turbines have relatively short starting time when compared to non-black-start (NBS) generating units. For this reason, wind farms need to participate in power system restoration after blackouts. The decision of restoring a wind farm depends on its output power and the characteristics of the power system. The power system restorat...

  10. Choice between reliable and unreliable reinforcement alternatives revisited: Preference for unreliable reinforcement

    OpenAIRE

    Belke, Terry W; Spetch, Marcia L

    1994-01-01

    Pigeons' choices between a reliable alternative that always provided food after a delay (i.e., 100% reinforcement) and an unreliable one that provided food or blackout equally often after a delay (i.e., 50% reinforcement) was studied using a discrete-trials concurrent-chains procedure modified to prevent choice between alternatives following a blackout outcome. Initial links were fixed-ratio 1 schedules, and terminal links were fixed-time schedules. Stimuli presented during the terminal-link ...

  11. ASCERTAINMENT OF ELECTRIC-SUPPLY SCHEMES RELIABILITY FOR THE ATOMIC POWER PLANT AUXILIARIES

    Directory of Open Access Journals (Sweden)

    A. L. Starzhinskij

    2015-01-01

    Full Text Available The paper completes ascertainment of electrical-supply scheme reliability for the auxiliaries of a nuclear power plant. Thereat the author considers the system behavior during the block normal operation, carrying out current maintenance, and capital repairs in combination with initiating events. The initiating events for reactors include complete blackout, i.e. the loss of outside power supply (normal and reserve; emergency switching one of the working turbogenerators; momentary dumping the normal rating to the level of auxiliaries with seating the cutout valve of one turbo-generator. The combination of any initiating event with the repairing mode in case of one of the system elements failure should not lead to blackout occurrence of more than one system of the reliable power supply. This requirement rests content with the help of the reliable power supply system self-dependence (electrical and functional and the emergency power-supply operational autonomy (diesel generator and accumulator batteries.The reliability indicators of the power supply system for the nuclear power plant auxiliaries are the conditional probabilities of conjoined blackout of one, two, and three sections of the reliable power supply conditional upon an initiating event emerging and the blackout of one, two, and three reliable power-supply sections under the normal operational mode. Furthermore, they also are the blackout periodicity of one and conjointly two, three, and four sections of normal operation under the block normal operational mode. It is established that the blackout of one bus section of normal operation and one section of reliable power-supply system of the auxiliaries that does not lead to complete blackout of the plant auxiliaries may occur once in three years. The probability of simultaneous power failure of two or three normal-operation sections and of two reliable power-supply sections during the power plant service life is unlikely.

  12. Analysis of Chain of Events in Major Historic Power Outages

    Directory of Open Access Journals (Sweden)

    HUANG, T.

    2014-08-01

    Full Text Available Contemporary power systems are facing increasing intricate conditions that have never been considered when initially designing the infrastructure, such as malicious threats, accommodating smart grids, etc. As a consequence, blackouts albeit seldom but stubbornly keep appearing from time to time the world around, and demonstrate their devastating capability to create vast damage on both power systems and the society at large. Patterns of the blackout starting from the first triggering events to the system final status have emerged. A framework of a coding system was proposed in this paper in order to capture the common feature in the system evolution during the development of cascades. Cascades in a blackout can be tracked by a chain of events with the help of the codes. It is facile to adopt the framework to build up a knowledge base of blackouts. By applying the proposed framework to 31 selected historic blackouts, most frequent events, effects and origins are identified; the findings can provide useful information for grid designers and security experts for ranking the most imminent issues in their study.

  13. Preliminary Assessment for the Mitigative Effectiveness of External Injection during Extended SBO

    Energy Technology Data Exchange (ETDEWEB)

    Park, S. Y.; Ahn, K. I. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The NRC performed the state-of-the-art reactor consequence analyses (SOARCA) project to develop best estimates of the offsite consequences for potential severe reactor accidents for two pilot plants: the Peach Bottom Atomic Power Station and the Surry Power Station. The short-term station blackout (STSBO) and long-term station blackout (LTSBO) were identified as one of major groups of accident scenarios for analysis. Both types of SBOs involve a loss of all alternating current (AC) power. SOARCA-like analyses, which were limited to accident progression except offsite consequences, were performed for OPR-1000 PWR. This paper illustrates the preliminary assessment for the mitigative effectiveness of external cooling water injection strategies using fire trucks during the potential extended station blackout accident.

  14. Severe accident source term characteristics for selected Peach Bottom sequences predicted by the MELCOR Code

    Energy Technology Data Exchange (ETDEWEB)

    Carbajo, J.J. [Oak Ridge National Lab., TN (United States)

    1993-09-01

    The purpose of this report is to compare in-containment source terms developed for NUREG-1159, which used the Source Term Code Package (STCP), with those generated by MELCOR to identify significant differences. For this comparison, two short-term depressurized station blackout sequences (with a dry cavity and with a flooded cavity) and a Loss-of-Coolant Accident (LOCA) concurrent with complete loss of the Emergency Core Cooling System (ECCS) were analyzed for the Peach Bottom Atomic Power Station (a BWR-4 with a Mark I containment). The results indicate that for the sequences analyzed, the two codes predict similar total in-containment release fractions for each of the element groups. However, the MELCOR/CORBH Package predicts significantly longer times for vessel failure and reduced energy of the released material for the station blackout sequences (when compared to the STCP results). MELCOR also calculated smaller releases into the environment than STCP for the station blackout sequences.

  15. Severe accident source term characteristics for selected Peach Bottom sequences predicted by the MELCOR Code

    International Nuclear Information System (INIS)

    The purpose of this report is to compare in-containment source terms developed for NUREG-1159, which used the Source Term Code Package (STCP), with those generated by MELCOR to identify significant differences. For this comparison, two short-term depressurized station blackout sequences (with a dry cavity and with a flooded cavity) and a Loss-of-Coolant Accident (LOCA) concurrent with complete loss of the Emergency Core Cooling System (ECCS) were analyzed for the Peach Bottom Atomic Power Station (a BWR-4 with a Mark I containment). The results indicate that for the sequences analyzed, the two codes predict similar total in-containment release fractions for each of the element groups. However, the MELCOR/CORBH Package predicts significantly longer times for vessel failure and reduced energy of the released material for the station blackout sequences (when compared to the STCP results). MELCOR also calculated smaller releases into the environment than STCP for the station blackout sequences

  16. MATCASC: A tool to analyse cascading line outages in power grids

    CERN Document Server

    Koç, Yakup; Araujo, Nuno A M; Warnier, Martijn

    2013-01-01

    Blackouts in power grids typically result from cascading failures. The key importance of the electric power grid to society encourages further research into sustaining power system reliability and developing new methods to manage the risks of cascading blackouts. Adequate software tools are required to better analyze, understand, and assess the consequences of the cascading failures. This paper presents MATCASC, an open source MATLAB based tool to analyse cascading failures in power grids. Cascading effects due to line overload outages are considered. The applicability of the MATCASC tool is demonstrated by assessing the robustness of IEEE test systems and real-world power grids with respect to cascading failures.

  17. Identification of Severe Multiple Contingencies in Electric PowerNetworks

    Energy Technology Data Exchange (ETDEWEB)

    Donde, Vaibhav; Lopez, Vanessa; Lesieutre, Bernard; Pinar, Ali; Yang,Chao; Meza, Juan

    2005-07-01

    In this paper we propose a two-stage screening and analysis process for identifying multiple contingencies that may result in very severe disturbances and blackouts. In a screening stage we form an optimization problem to find the minimum change in the network to move the power flow feasibility boundary to the present operating point and that will cause the system to separate with a user-specified power imbalance. The lines identified by the optimization program are used in a subsequent analysis stage to find combinations that may lead to a blackout. This approach is applied to a 30-bus system with encouraging results.

  18. Handbook of electrical power system dynamics modeling, stability, and control

    CERN Document Server

    Eremia, Mircea

    2013-01-01

    Complete guidance for understanding electrical power system dynamics and blackouts This handbook offers a comprehensive and up-to-date treatment of power system dynamics. Addressing the full range of topics, from the fundamentals to the latest technologies in modeling, stability, and control, Handbook of Electrical Power System Dynamics provides engineers with hands-on guidance for understanding the phenomena leading to blackouts so they can design the most appropriate solutions for a cost-effective and reliable operation. Focusing on system dynamics, the book details

  19. Numerical simulation of temperature and thermal stress of the reactor vessel in CEFR

    International Nuclear Information System (INIS)

    The interior sodium flow of the reactor vessels in CEFR is simulated by Fluent and the whole temperature of hot plenum and cold plenum under normal condition is obtained. It validates the whole simulation based on analyzing the temperature of simulation and experiment. The work will provide important basis for further analysis of temperature under station blackout accident of CEFR. According to the existing temperature of reactor vessels, it computes the thermal stress of reactor vessel cooling system by ANSYS. In the end, it gives the distribution of thermal stress under normal condition and station blackout accident condition. (authors)

  20. Introducing Renewable Energy Education into an Engineering Technology Program

    Science.gov (United States)

    This paper presents the first stage to implement green energy education into an engineering technology program making use of a solar power generation station. As issues such as climate change, global warming, increased blackouts, and oil price fluctuation continue to pepper the news, it is likely th...

  1. Electrical energy systems

    CERN Document Server

    El-Hawary, Mohamed E

    2007-01-01

    Features discussions ranging from the technical aspects of generation, transmission, distribution, and utilization to power system components, theory, protection, and the energy control center that offer an introduction to effects of deregulating electric power systems, blackouts and their causes, and minimizing their effects.

  2. Contingency-Constrained Unit Commitmentin Meshed Isolated Power Systems

    DEFF Research Database (Denmark)

    Sokoler, Leo Emil; Vinter, Peter; Bærentsen, Runi;

    2015-01-01

    and a modelling point of view. We compare the ORPP to a unit commitment problem that only considers the stationary behavior of the frequency. Simulations based on a Faroe Islands case study show that, without being overly conservative, potential blackouts and power outages can be avoided using the...

  3. Decentralized planning of energy demand for the management of robustness and discomfort

    NARCIS (Netherlands)

    Pournaras, E.; Vasirani, M.; Kooij, R.E.; Aberer, K.

    2014-01-01

    The robustness of smart grids is challenged by unpredictable power peaks or temporal demand oscillations that can cause blackouts and increase supply costs. Planning of demand can mitigate these effects and increase robustness. However, the impact on consumers in regards to the discomfort they exper

  4. Power grid complexity

    CERN Document Server

    Mei, Shengwei; Cao, Ming

    2011-01-01

    This book introduces self-organized criticality (SOC) theory and complex network theory and applies them to power systems. It examines four blackout models based on SOC theory and studies the SOC of power systems at both the macroscopic and microscopic levels.

  5. You're Distracted. This Professor Can Help

    Science.gov (United States)

    Parry, Marc

    2013-01-01

    The e-mail drill was one of numerous mind-training exercises in a unique class designed to raise students' awareness about how they use their digital tools. Colleges have experimented with short-term social-media blackouts in the past. But Ms. Hill's course, "Information and Contemplation," goes way further. Participants scrutinize their use of…

  6. Energy systems security

    CERN Document Server

    Voeller, John G

    2014-01-01

    Energy Systems Security features articles from the Wiley Handbook of Science and Technology for Homeland Security covering topics related to electricity transmission grids and their protection, risk assessment of energy systems, analysis of interdependent energy networks. Methods to manage electricity transmission disturbances so as to avoid blackouts are discussed, and self-healing energy system and a nano-enabled power source are presented.

  7. Context-independent centrality measures underestimate the vulnerability of power grids

    NARCIS (Netherlands)

    Verma, T.; Ellens, W.; Kooij, R.E.

    2015-01-01

    Power grids vulnerability is a key issue in society. A component failure may trigger cascades of failures across the grid and lead to a large blackout. Within complex network analysis, structural vulnerabilities of power grids have been studied mostly using purely topological approaches, which assum

  8. Construction of a low cost wind energy generator; Construcao de um gerador de energia eolica de baixo custo

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Jonathan Penha de; Almeida, Silvio Carlos Anibal de [Universidade Federal do Rio de Janeiro (DEM/EP/UFRJ), RJ (Brazil). Escola Politecnica. Dept. de Engenharia Mecanica], Emails: jonathan_penha@poli.ufrj.br, silvioa@gmail.com

    2010-07-01

    This project presents a low cost wind electric power generator constituted of cheap and easy access materials. The necessary materials are presented for it construction and the expected efficiency, having as reference the city of Fernando de Noronha, Brazil. The elaboration of the generator was initially developed as alternative energy source during blackout.

  9. 47 CFR 76.95 - Exceptions.

    Science.gov (United States)

    2010-10-01

    ... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout... serve a copy of that notice on every television station that would be entitled to exercise network non... priority station for one hour following the scheduled time of completion of the broadcast of a live...

  10. 78 FR 16876 - Biweekly Notice; Applications and Amendments to Facility Operating Licenses and Combined Licenses...

    Science.gov (United States)

    2013-03-19

    ... March 6, 2013. The last biweekly notice was published on March 4, 2013 (78 FR 14126). ADDRESSES: You may... be filed in accordance with the NRC E-Filing rule (72 FR 49139; August 28, 2007). The E-Filing... source providing acceptable capability to withstand station blackout under 10 CFR 50.63(c)(2). The...

  11. 77 FR 18874 - Virginia Electric and Power Company; Receipt of Request for Action

    Science.gov (United States)

    2012-03-28

    ... Virginia Electric and Power Company's (the licensee's) North Anna Power Station, Units 1 and 2 (North Anna... North Anna 1 and 2. (13) Concerns exist about the response of North Anna 1 and 2, to a prolonged station blackout. (14) The current emergency evacuation plans for North Anna 1 and 2, need to be revised to...

  12. 77 FR 63343 - Biweekly Notice: Applications and Amendments to Facility Operating Licenses and Combined Licenses...

    Science.gov (United States)

    2012-10-16

    .... The last biweekly notice was published on October 2, 2012 (77 FR 60146- 60160). Addresses: You may... accordance with the NRC E-Filing rule (72 FR 49139; August 28, 2007). The E-Filing process requires... power any E-bus within one hour from the Station Blackout (SBO) event, and with the capacity to...

  13. 77 FR 23161 - Onsite Emergency Response Capabilities

    Science.gov (United States)

    2012-04-18

    ... known as station blackout (SBO). One diesel generator remained functional on Unit 6. Despite the actions... formalized in the Power Reactor Security Requirements final rule (74 FR 13926; March 27, 2009) in 10 CFR 50... Resources Defense Council (NRDC) in a petition for rulemaking (PRM), PRM-50-102 (76 FR 58165; September...

  14. 10 CFR 54.4 - Scope.

    Science.gov (United States)

    2010-01-01

    ... CFR 50.62), and station blackout (10 CFR 50.63). (b) The intended functions that these systems... during and following design-basis events (as defined in 10 CFR 50.49 (b)(1)) to ensure the following... demonstrates compliance with the Commission's regulations for fire protection (10 CFR 50.48),...

  15. 75 FR 57521 - Biweekly Notice Applications and Amendments to Facility Operating Licenses Involving No...

    Science.gov (United States)

    2010-09-21

    ... September 7, 2010 (75 FR 54390- 54400). Notice of Consideration of Issuance of Amendments to Facility... accordance with the NRC E-Filing rule (72 FR 49139, August 28, 2007). The E-Filing process requires... inventory to be maintained to supply AFW pump suction in the event of a Station Blackout, when the...

  16. "Musta Peetri" stuudio Nafta näitab uusi lühifilme / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2010-01-01

    Filmistuudio Nafta lühifilmide kava 1. oktoobrist 2010 Tallinna kinos Artis. Kavasse kuuluvad uued linateosed Heleri Saariku "Näkilugu" ja Margus Paju "Blackout" ning Priit Pääsukese "Must Peeter" (2008), Peeter Sauteri novelli "Must notsu" ekraniseering

  17. 76 FR 58303 - Biweekly Notice; Applications and Amendments to Facility Operating Licenses Involving No...

    Science.gov (United States)

    2011-09-20

    ... September 6, 2011 (76 FR 55125). ADDRESSES: Please include Docket ID NRC-2011-0216 in the subject line of...), must be filed in accordance with the NRC E-Filing rule (72 FR 49139, August 28, 2007). The E-Filing... supplies or change the ability of the plant to cope with station blackout events. Therefore, the...

  18. 47 CFR 76.123 - Satellite syndicated program exclusivity.

    Science.gov (United States)

    2010-10-01

    ... Exclusivity and Sports Blackout § 76.123 Satellite syndicated program exclusivity. (a) Upon receiving... station licensed by the Commission, a program carried on a nationally distributed superstation or on a station carried pursuant to § 76.54 of this chapter when the syndicated program exclusivity rights to...

  19. 77 FR 74788 - Long-Term Cooling and Unattended Water Makeup of Spent Fuel Pools

    Science.gov (United States)

    2012-12-18

    ... temporarily constrict power generation. On May 6, 2011 (76 FR 26223), the NRC published a notice of receipt and request for public comment for this petition in the Federal Register (FR). The public comment... require capabilities to withstand a station blackout (10 CFR 50.63, ``Loss of all alternating...

  20. Kinos voolab naftat / Tiit Tuumalu

    Index Scriptorium Estoniae

    Tuumalu, Tiit, 1971-

    2010-01-01

    Filmistuudio Nafta lühifilmide kava 1. oktoobrist 2010 Tallinna kinos Artis. Kavasse kuuluvad uued linateosed: Heleri Saariku "Näkilugu" ja Margus Paju "Blackout" ning Priit Pääsukese "Must Peeter" (2008), Peeter Sauteri novelli "Must notsu" ekraniseering

  1. 78 FR 37849 - Advisory Committee on Reactor Safeguards; Notice of Meeting

    Science.gov (United States)

    2013-06-24

    ..., Uncertainty Analysis of the Unmitigated Long-Term Station Blackout of the Peach Bottom Atomic Power Station... October 18, 2012, (76 FR 64146-64147). In accordance with those procedures, oral or written views may be... Specific Review Standard for mPower iPWR Chapter 7, ``Instrumentation and Control Systems;'' (3)...

  2. 47 CFR 76.107 - Exclusivity contracts.

    Science.gov (United States)

    2010-10-01

    ... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.107 Exclusivity contracts. A distributor or television station exercising exclusivity pursuant to... exclusivity contracts, such portions to be signed by both the distributor and the television station,...

  3. Stuart Brisley etendused inimliku ja kunstipärase piiril / Andri Ksenofontov

    Index Scriptorium Estoniae

    Ksenofontov, Andri, 1962-

    2009-01-01

    Stuart Brisley näitus "Crossings" ("Ületamised") Tallinna Linnagaleriis 19- sept. - 4. oktoobrini. Heli- ja valgusinstallatsioonist "Touching Black Ice" Titanicu hukkumisest 1912. a. 15. aprillil. Videoinstallatsioonist "Blackout" Estonia hukkumisest 1994. a. 28. septembril. Näitusega kaasnevast kataloogist. Stuart Brisley loomingust

  4. 47 CFR 76.101 - Cable syndicated program exclusivity: extent of protection.

    Science.gov (United States)

    2010-10-01

    ..., Syndicated Exclusivity and Sports Blackout § 76.101 Cable syndicated program exclusivity: extent of... are held by a commercial television station licensed by the Commission, shall not carry that program... to each syndicated program, the geographic zone within which the television station is entitled...

  5. 75 FR 16913 - Transmission Relay Loadability Reliability Standard

    Science.gov (United States)

    2010-04-02

    ...\\ Transmission Relay Loadability Reliability Standard, Notice of Proposed Rulemaking, 74 FR 35830 (Jul. 21, 2009... with protective relays, voltage and current sensing devices, station batteries, and DC control... in service. 3. Following the August 2003 blackout that affected parts of the Midwest and...

  6. Eesti elektrisüsteemi juhtimiskeskus kasutab ülimoodsat tehnikat / Raigo Neudorf

    Index Scriptorium Estoniae

    Neudorf, Raigo

    2007-01-01

    Eesti Energia kontserni kuuluva OÜ Põhivõrk juhtimiskeskust Tallinnas Kadaka teel tutvustab elektrisüsteemi juhtimise osakonna juhataja Valeri Peterson. Vt. samas: Blackout välistatud; Häkkerite hammas keskusele peale ei hakka; Küsimusele Põhivõrgu IT-eelarve kohta vastab OÜ Põhivõrk kommunikatsioonijuht Kätlin Kruus

  7. 47 CFR 76.94 - Notification.

    Science.gov (United States)

    2010-10-01

    ... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout... of the party requesting non-duplication protection and the television broadcast station holding the... otherwise made available: (1) Newspapers or magazines of general circulation. (2) A television station...

  8. 47 CFR 76.105 - Notification.

    Science.gov (United States)

    2010-10-01

    ... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout... television broadcast station or other party holding the exclusive right; (2) The name of the program or...; (2) A television station whose programs may be subject to deletion. If a cable television system...

  9. (Ne)přirozený svět?

    Czech Academy of Sciences Publication Activity Database

    Lahoda, Vojtěch

    Řevnice : Arbor vitae, 2011 - (Rousová, H.), s. 201-222 ISBN 978-80-87164-64-8 Institutional research plan: CEZ:AV0Z80330511 Keywords : Protectorate * Seven in October * Pavel Kropáček * blackout * Jindřich Chalupecký * Zdeněk Tůma Subject RIV: AL - Art, Architecture, Cultural Heritage

  10. A robustness metric for cascading failures by targeted attacks in power networks

    NARCIS (Netherlands)

    Koc, Y.; Warnier, M.; Kooij, R.E.; Brazier, F.M.T.

    2013-01-01

    Cascading failures are the main reason blackouts occur in power networks. The economic cost of such failures is in the order of tens of billion dollars annually. In a power network, the cascading failure phenomenon is related to both topological properties (number and types of buses, density of tran

  11. Independent review of SCDAP/RELAP5 natural circulation calculations

    International Nuclear Information System (INIS)

    A review and assessment of the uncertainties in the calculated response of reactor coolant system natural circulation using the SCDAP/RELAP5 computer code were completed. The SCDAP/RELAP5 calculation modeled a station blackout transient in the Surry nuclear power plant and concluded that primary system depressurization from natural circulation induced primary system failure is more likely than previously thought

  12. Lessons from the South African Electricity Crisis

    OpenAIRE

    Bayliss, Kate

    2008-01-01

    South Africa is suffering an electricity crisis. Blackouts have been widespread and the impact disastrous. Electricity supply is predicted to constrain growth for at least the next five years. How could this have occurred when until recently South Africa had a surplus of cheap electricity? This One Pager explores the causes. (...)

  13. Corrections. Inverter standards were wrong and must be amended - but who will pay for it?; Die Korrekturen. Weil Wechselrichternormen falsch waren, soll nun nachgeruestet werden - doch wer bezahlt das?

    Energy Technology Data Exchange (ETDEWEB)

    Beneking, Andreas

    2011-05-15

    Inverters should not shut off early when the grid frequency is fluctuating, for this would cause grid instabilities and even large-area blackout. This has long been known but was always neglected by the power industry. As a result, the solar industry is faced with an enormous need for retrofitting. While the cost will be acceptable, nobody appears to be prepared to pay.

  14. Resolution of GSI B-56 - Emergency diesel generator reliability

    International Nuclear Information System (INIS)

    The need for an emergency diesel generator (EDG) reliability program has been established by 10 CFR Part 50, Section 50.63, Loss of All Alternating Current Power, which requires that licensees assess their station blackout coping and recovery capability. EDGs are the principal emergency ac power sources for avoiding a station blackout. Regulatory Guide 1.155, Station Blackout, identifies a need for (1) a nuclear unit EDG reliability level of at least 0.95, and (2) an EDG reliability program to monitor and maintain the required EDG reliability levels. NUMARC-8700, Guidelines and Technical Bases for NUMARC Initiatives Addressing Station Blackout at Light Water Reactors, also provides guidance on such needs. The resolution of GSI B-56, Diesel Reliability will be accomplished by issuing Regulatory Guide 1.9, Rev. 3, Selection, Design, Qualification, Testing, and Reliability of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Plants. This revision will integrate into a single regulatory guide pertinent guidance previously addressed in R.G. 1.9, Rev. 2, R.G. 1.108, and Generic Letter 84-15. R.G. 1.9 has been expanded to define the principal elements of an EDG reliability program for monitoring and maintaining EDG reliability levels selected for SBO. In addition, alert levels and corrective actions have been defined to detect a deteriorating situation for all EDGs assigned to a particular nuclear unit, as well as an individual problem EDG

  15. Our Lyrics Will Not Be on Lockdown: An Arts Collective's Response to an Incarceration Nation

    Science.gov (United States)

    Green, Keisha

    2010-01-01

    Recognizing the unprecedented proliferation of prisons in the United States, Blackout Arts Collective (BAC), a grassroots organization working to empower communities of color through the arts, education, and activism, launched a national tour--"Lyrics on Lockdown (LOL): Slamming the Prison Industrial Complex." As a BAC member, I participated in…

  16. Non-iterative Voltage Stability

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, Yuri V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Vyakaranam, Bharat [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hou, Zhangshuan [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wu, Di [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Meng, Da [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Shaobu [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Elbert, Stephen T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Miller, Laurie E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Huang, Zhenyu [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-09-30

    This report demonstrates promising capabilities and performance characteristics of the proposed method using several power systems models. The new method will help to develop a new generation of highly efficient tools suitable for real-time parallel implementation. The ultimate benefit obtained will be early detection of system instability and prevention of system blackouts in real time.

  17. Saving electricity in a hurry. Dealing with temporary shortfalls in electricity supplies

    Energy Technology Data Exchange (ETDEWEB)

    none

    2005-07-01

    Blackouts are normally the result of imbalances in electricity supply and demand. A brief blackout is mostly an inconvenience. But persistent shortfalls ? those lasting days, weeks, or months ? can cause economic disruption and danger to human life in our technology-rich societies. Saving Electricity in a Hurry describes some of the recent power shortfalls, from Norway to New Zealand, from Tokyo to Arizona and the policies these regions used to quickly reduce their power consumption. How did the whole country of Sweden cut its power consumption by 4% in only three days? How did California save 14% in only a few months? While the temporary shortfalls in electricity supplies described in this book are relatively rare events, they disproportionately shape future energy policies. Saving Electricity in a Hurry shows that countries can quickly reduce electricity consumption without harming the economy as much as blackouts or unplanned curtailments. The strategies are diverse, unique and often surprisingly cheap. They include mass media campaigns ? where a good joke can save a Megawatt ? improvements in equipment efficiency and quickly adjusting electricity prices. This book explains how California replaced a million traffic signals with energy-saving models, how millions of Tokyo residents raised their thermostat settings, and how New Zealanders took shorter showers, all quickly enough to help avoid imminent blackouts. Finally, it connects these policies to the traditional goal of ?saving electricity slowly?.

  18. Independent review of SCDAP/RELAP5 natural circulation calculations

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, G.M.; Gross, R.J.; Martinez, M.J.; Rightley, G.S.

    1994-01-01

    A review and assessment of the uncertainties in the calculated response of reactor coolant system natural circulation using the SCDAP/RELAP5 computer code were completed. The SCDAP/RELAP5 calculation modeled a station blackout transient in the Surry nuclear power plant and concluded that primary system depressurization from natural circulation induced primary system failure is more likely than previously thought.

  19. Review of Network Topologies and Protection Principles in Marine and Offshore Applications

    DEFF Research Database (Denmark)

    Ciontea, Catalin-Iosif; Bak, Claus Leth; Blaabjerg, Frede;

    2015-01-01

    An electric fault that is not cleared is harmful in land applications, but in marine and offshore sector it can have catastrophic consequences. If the protection system fails to operate properly, the following situation may occur: blackouts, fire, loss of propulsion, delays in transportation...... them. Also, a brief overview of the protection principles for a generic power system is presented....

  20. 47 CFR 76.92 - Cable network non-duplication; extent of protection.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Cable network non-duplication; extent of... RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.92 Cable network non-duplication; extent of protection....

  1. 47 CFR 76.122 - Satellite network non-duplication.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Satellite network non-duplication. 76.122... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.122 Satellite network non-duplication. (a) Upon receiving notification pursuant...

  2. 47 CFR 76.93 - Parties entitled to network non-duplication protection.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Parties entitled to network non-duplication... RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.93 Parties entitled to network non-duplication...

  3. Californian labs feel the heat of the energy crisis

    CERN Multimedia

    Dalton, R B

    2001-01-01

    Laboratories operating for the DOE have been told their power may be shut off for up to two hours at a time. Warmer weather has increased the use of air conditioning and the blackouts are expected to become more frequent over the summer (1/2 page).

  4. Dynamic analysis of diesel generator system after loss of offsite power event occurring in nuclear power plants

    International Nuclear Information System (INIS)

    Based on the GO methodology and Markov method, the dynamic analysis of emergency diesel generator system for protecting the nuclear power plant from Station Blackout, which is caused by Loss of Offsite Power event, is made with duration of 24 hours. In addition, the accurate reliability calculation problem is solved for the repairable system with dependant maintenance relation, and the logic relation of emergency response system is fully simulated by creating the 'Backup Operator' of the GO methodology. By combining the two reliability analysis methods, which is used suitably for the emergency response system of diesel generators with dependant maintenance relation, the application range for the two methods is expanded, and the effect of station blackout event on the safety operation of nuclear power plants can be obtained more accurately. (author)

  5. A matching approach to communicate through the plasma sheath surrounding a hypersonic vehicle

    International Nuclear Information System (INIS)

    In order to overcome the communication blackout problem suffered by hypersonic vehicles, a matching approach has been proposed for the first time in this paper. It utilizes a double-positive (DPS) material layer surrounding a hypersonic vehicle antenna to match with the plasma sheath enclosing the vehicle. Analytical analysis and numerical results indicate a resonance between the matched layer and the plasma sheath will be formed to mitigate the blackout problem in some conditions. The calculated results present a perfect radiated performance of the antenna, when the match is exactly built between these two layers. The effects of the parameters of the plasma sheath have been researched by numerical methods. Based on these results, the proposed approach is easier to realize and more flexible to the varying radiated conditions in hypersonic flight comparing with other methods

  6. Fission product revaporization

    International Nuclear Information System (INIS)

    One of the major developmental advances in severe accident analysis since the Reactor Safety Study relates to the accounting for radionuclide retention in the reactor coolant system (RCS). The retention is predicted to occur as materials released during core heatup and degradation are transported through the RCS to the break (broken pipe, relief valve, etc.). For accidents involving relatively long RCS-transit times (e.g., station blackout in PWRs), the fraction of released material predicted to remain in the RCS can be large. For example, calculations for the Surry station blackout sequence showed retention of approximately 80% of the cesium and iodine species. Factors affecting fission product revaporization are post-vessel-failure thermal hydraulics, heat loss through vessel and pipe walls, and revaporization chemistry. The accident conditions relevant to this issue range from those present immediately after vessel failure to those present after containment failure. The factors that affect fission product revaporization are discussed

  7. System Simulation and Implementation of SIPS in Taiwan

    Directory of Open Access Journals (Sweden)

    Chao-Rong Chen

    2014-01-01

    Full Text Available This study describes the system simulation and implementation of the system integrity protection schemes (SIPS in an independent, intensive, and island-type power system. It also elucidates a smart grid plan to provide grid security in this power grid. The proposed SIPS can prevent blackouts that could otherwise result from the transient instability of N-3 contingencies and has been fully implemented and operated. The entire SIPS installation comprises two stages. The first-stage SIPS takes generator tripping system simulation and the second-stage SIPS involves generator tripping, load rejection, and bus-tie switching countermeasures. The proposed SIPS can prevent isolated power system blackout from extreme contingencies system and provide a valuable system simulation experience for similar independent power grids.

  8. Automatic Synchronization as the Element of a Power System's Anti-Collapse Complex

    Science.gov (United States)

    Barkāns, J.; Žalostība, D.

    2008-01-01

    In the work, a new universal technical solution is proposed for blackout prevention in a power system, which combines the means for its optimal short-term sectioning and automatic self-restoration to normal conditions. The key element of self-restoration is automatic synchronization. The authors show that for this purpose it is possible to use automatic re-closing with a device for synchronism-check. The results of computations, with simplified formulas and a relevant mathematical model employed, indicate the area of application for this approach. The proposed solution has been created based on many-year experience in the liquidation of emergencies and on the potentialities of equipment, taking into account new features of blackout development that have come into being recently.

  9. Detection of vulnerable relays and sensitive controllers under cascading events based on performance indices

    DEFF Research Database (Denmark)

    Liu, Zhou; Chen, Zhe; Hu, Yanting

    ) based detection strategy is proposed to identify the vulnerable relays and sensitive controllers under the overloading situation during cascading events. Based on the impedance margin sensitivity, diverse performance indices are proposed to help improving this detection. A study case of voltage......The unexpected relay operations have been regarded as one of main reasons to propagate and induce the cascaded blackouts. It is significant to timely detect vulnerable relays to be blocked, and locate sensitive controllers to regulate the emergency states. In this paper, a multi agent system (MAS...... instability induced cascaded blackout built in real time digital simulator (RTDS) will be used to demonstrate the proposed strategy. The simulation results indicate this strategy can effectively detect the vulnerable relays and sensitive controllers under overloading situations....

  10. Curing critical links in oscillator networks as power grid models

    CERN Document Server

    Rohden, Martin; Timme, Marc; Meyer-Ortmanns, Hildegard

    2015-01-01

    Modern societies crucially depend on the robust supply with electric energy. Blackouts of power grids can thus have far reaching consequences. During a blackout, often the failure of a single infrastructure, such as a critical transmission line, results in several subsequent failures that spread across large parts of the network. Preventing such large-scale outages is thus key for assuring a reliable power supply. Here we present a non-local curing strategy for oscillatory power grid networks based on the global collective redistribution of loads. We first identify critical links and compute residual capacities on alternative paths on the remaining network from the original flows. For each critical link, we upgrade lines that constitute bottlenecks on such paths. We demonstrate the viability of this strategy for random ensembles of network topologies as well as topologies derived from real transmission grids and compare the nonlocal strategy against local back-ups of critical links. These strategies are indep...

  11. Condition monitoring of medium voltage electrical cables by means of partial discharge measurements

    OpenAIRE

    Van Jaarsveldt, H.; Gouws, R

    2014-01-01

    The purpose of this paper is to discuss condition monitoring (CM) of medium voltage electrical cables by means of partial discharge (PD) measurements. Electrical cables are exposed to a variety of operational and environmental stressors. The stressors will lead to the degradation of the cable’s insulation material and ultimately to cable failure. The premature failure of cables can cause blackouts and will have a significant effect on the safety of such a network. It is therefore ...

  12. Contribution of Water Saving to a Stable Power Supply in Vietnam

    OpenAIRE

    Takayuki Otani; Kanako Toyosada; Yasutoshi Shimizu

    2015-01-01

    In Vietnam, the rapid expansion of cities is exceeding the supply capacity for water and electricity, and restrictions on water supply and blackouts occur on a daily basis. In this study, the authors examined whether water-saving equipment could solve these problems. This paper focused on toilet bowls that consumed a large amount of water, and on showers for which heat consumption was high. In Vietnam, the main heat source for showers is the electric water heater, typically having a power con...

  13. Decision method for the investment in shunt capacitors based on a long-term voltage stability analysis

    OpenAIRE

    Cazaux, Vincent

    2012-01-01

    As the electric consumption increases and the constraints multiply, the grid becomes weaker and may not be able to face critical voltage stability problems. Indeed, in the past decades some blackouts occurred in Europe and America, due to voltage instabilities. At a 5-year horizon, new lines or new power plants cannot be built in time, it is therefore necessary to invest in capacitors to prevent voltage collapses. The core of this project is the best localization of these investments, to make...

  14. Contextualizing the power of social media: Technology, communication and the Libya Crisis

    OpenAIRE

    Morris, Laura

    2014-01-01

    At the beginning of 2011, revolution across the MENA region threw into question the potential power of new media to bring about large-scale revolutionary pursuits. In Libya, the correlation between social media usage and social upheavals seemed, at most, tenuous in light of low levels of Internet penetration generally and in light of the state-sponsored Internet blackout following the nation-wide protests there. This qualitative research intends, through content analysis and semi-structured i...

  15. Dispersed trading and the prevention of market failure

    DEFF Research Database (Denmark)

    Porter, David C.; Tanggaard, Carsten; Weaver, Daniel G.;

    2008-01-01

    With augmented demands on power grids resulting in longer and larger blackouts combined with heightened concerns of terrorist attacks, trading institutions and policy makers have widened their search for systems that avoid market failure during these disturbing events. We provide insight into this...... combined with widely dispersed trading locations may be a viable means of protection against market failure during massive power disruptions or terrorist attacks....

  16. Dispersed Trading and the Prevention of Market Failure

    DEFF Research Database (Denmark)

    Porter, David C.; Tanggaard, Carsten; G. Weaver, Daniel;

    With augmented demands on power grids resulting in longer and larger blackouts combined with heightened concerns of terrorist attacks, trading institutions and policy makers have widened their search for systems that avoid market failure during these disturbing events. We provide insight into this...... combined with widely dispersed trading locations may be a viable means of protection against market failure during massive power disruptions or terrorist attacks....

  17. Identification of Optimal Path in Power System Network Using Bellman Ford Algorithm

    OpenAIRE

    S.hemalatha; P. Valsalal

    2012-01-01

    Power system network can undergo outages during which there may be a partial or total blackout in the system. In that condition, transmission of power through the optimal path is an important problem in the process of reconfiguration of power system components. For a given set of generation, load pair, there could be many possible paths to transmit the power. The optimal path needs to consider the shortest path (minimum losses), capacity of the transmission line, voltage stability, priority o...

  18. Analysis of the damage domains of sbo sequences with rcp passive thermal shutdown

    OpenAIRE

    Queral Salazar, José Cesar; Mena-Rosell, L.; Jimenez Varas, Gonzalo; Sánchez-Perea, M.; Hortal, J.; Gómez-Magán, J.

    2014-01-01

    The integrated Safety Assessment (ISA) methodology, developed by the Spanish Nuclear Safety Council (CSN), has been applied to a thermal-hydraulic analysis of PWR Station Blackout (SBO) sequences in the context of the IDPSA (Integrated Deterministic-Probabilistic Safety Assessment) network objectives. The ISA methodology allows obtaining the damage domain (the region of the uncertain parameters space where the damage limit is exceeded) for each sequence of interest as a function of the operat...

  19. Influence of Modelling Options in RELAP5/SCDAPSIM and MAAP4 Computer Codes on Core Melt Progression and Reactor Pressure Vessel Integrity

    OpenAIRE

    Siniša Šadek; Srđan Špalj; Bruno Glaser

    2010-01-01

    RELAP5/SCDAPSIM and MAAP4 are two widely used severe accident computer codes for the integral analysis of the core and the reactor pressure vessel behaviour following the core degradation. The objective of the paper is the comparison of code results obtained by application of different modelling options and the evaluation of influence of thermal hydraulic behaviour of the plant on core damage progression. The analysed transient was postulated station blackout in NPP Krško with a leakage from ...

  20. A Deterministic/probalistic analysis of Ex-Vessel melt risk in a BWR

    OpenAIRE

    Abal López, Javier

    2006-01-01

    The present study is concerned with deterministic and probabilistic analysis of ex-vessel melt risks in a Swedish designed BWR plant. The focus is placed on a station blackout (SBO) scenario, with immediate SCRAM and subsequent activation of the main steam valve isolation (at 52 s). Four sequences were examined in detail to study the effect of two valves systems related to the operation of ADS (Automatic Depressurization System), and cavity flooding by water from suppression po...

  1. The conceptual design and development of a micro gas turbine generator / Matthys M. Steyn

    OpenAIRE

    Steyn, Matthys Miechielse

    2006-01-01

    All over the world interest in small scale stand alone power generators is growing. This interest is motivated by lower electrical costs and/or the capability to be unaffected by power failures and blackouts that could damage electronic networks and machinery. The potential of small scale power supplying units is being recognized, as generating capacity is quickly becoming too small. Furthermore, the need for off-grid power supply to remote areas, additional power supply to red...

  2. リフレクトメータによる機体まわりのプラズマ電子密度測定

    OpenAIRE

    Ito, Takeshi; Takaki, Ryoji; Teraoka, Ken; 伊藤 健; 高木 亮治; 寺岡 謙

    1996-01-01

    It is known to become a plasma state by electrolyzing the gas around the vehicle under hypersonic speed flight. Therefore, the radio wave is reflected by the plasma layer, and the blackout phenomena occurs. In the other, it is also reported that temperature, pressure and density around the vehicle deviates from the prediction which do not assume electrolyzing of the gas. Although it is difficult to obtain the such kind of data in the ground test, present HYFLEX (Hypersonic Flight Experiment) ...

  3. Otimização em regime de mercado da produção de eletricidade num parque eólico com bombagem associada

    OpenAIRE

    Gomes, João Rodrigo Graça

    2015-01-01

    Tese de mestrado integrado, Engenharia da Energia e do Ambiente, Universidade de Lisboa, Faculdade de Ciências, 2015 Operating the electric system means that at each moment the supply must exactly match demand or it will create disturbance in the grid frequency which can ultimately cause blackouts and supply disruption. This notion is even more important with the integration of power generated by renewables, with variable availability over time, in electric power systems. In the recent pas...

  4. Demand Response Spinning Reserve Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph H.; Nelson-Hoffman, Janine; Torres, Carlos; Hirth,Scott; Yinger, Bob; Kueck, John; Kirby, Brendan; Bernier, Clark; Wright,Roger; Barat, A.; Watson, David S.

    2007-05-01

    The Demand Response Spinning Reserve project is a pioneeringdemonstration of how existing utility load-management assets can providean important electricity system reliability resource known as spinningreserve. Using aggregated demand-side resources to provide spinningreserve will give grid operators at the California Independent SystemOperator (CAISO) and Southern California Edison (SCE) a powerful, newtool to improve system reliability, prevent rolling blackouts, and lowersystem operating costs.

  5. A PMU-Based Three-Step Controlled Separation with Transient Stability Considerations

    OpenAIRE

    Wang, C; Hou, Y.

    2014-01-01

    Controlled separation has been identified as one of the critical strategies to prevent a blackout of a bulk power system following a severe disturbance. To implement this critical strategy, optimal splitting points have to be identified subject to a series of steady-state and dynamic constraints. In this paper, a systematic controlled separation with three steps is proposed to cover steady-state and dynamic constraints with PMU measurements. At the first step, the power flow tracing method is...

  6. Managing with the Changing Competitive Landscape in Malaysia’s Power Generation Market through Sustainable Innovation

    OpenAIRE

    Hamzah, Rosman

    2014-01-01

    Today’s power generation market in Malaysia has evolved into a competitive market. In the beginning, there was no competition. The market was monopolised by a single utility. A nation-wide blackout triggered the introduction of independent power producers (IPPs) into the market in 1993. The market was transformed into an oligopoly market dominated by a few politically linked companies. These pioneering IPPs were awarded with IPP concessions without open tender. Pressured by increasing cost of...

  7. Understanding the response of commercial and institutional organizations to the California energy crisis. A report to the California Energy Commission - Sylvia Bender, Project Manager

    OpenAIRE

    Lutzenhiser, Loren; Janda, Kathryn; Kunkle, Rick; Payne, Christopher

    2002-01-01

    Beginning in the summer of 2000, California experienced serious energy supply problems, sharp increases in wholesale (and retail) electricity and natural gas prices, and isolated blackouts. In response to the rapidly worsening electricity situation in California in late 2000, the state set, as an initial goal, the reduction of the state's peak demand for the summer of 2001 by 5,000 megawatts. To meet this goal, the governor and legislature took a variety of steps to enhance supply, enco...

  8. Acute respiratory distress following the inhalation of an aerosol upholstery cleaner: the importance of reporting from the Emergency Department

    OpenAIRE

    Mistry, Dipak; Meredith, Carolyn

    2009-01-01

    Aerosols are commonplace in the home and in industry as they provide a quick and controlled way of distributing chemicals or perfumes. It is well known that deliberating concentrating and inhaling vapours may result in dizziness, euphoria, blackouts, respiratory distress, cardiac and renal failure. However, in the most part, warnings and guidance on use are sparse. Here, a proven case of acute respiratory distress is presented and a reporting mechanism via the UK National Poisons Information ...

  9. Coordination of protection system and VSC-HVDC to mitigate cascading failures

    OpenAIRE

    Leelaruji, Rujiroj

    2010-01-01

    The rapid development of the global economics has made power systems allover the world become large-scale interconnected grids. This increases the capabilityof power grids to transfer power over the long distance to serve the desiredpower demand with the minimum cost of operation. Unfortunately, it alsoenables the propagation of local failures into global networks. In other words,if a blackout happens in a power system, the size and the damage may significantlyincrease. One of the main ways i...

  10. Identification of Severe Multiple Contingencies in Electric Power Networks

    OpenAIRE

    Donde, Vaibhav; Lopez, Vanessa; Lesieutre, Bernard; Pinar, Ali; Yang, Chao; Meza, Juan

    2005-01-01

    In this paper we propose a two-stage screening and analysis process for identifying multiple contingencies that may result in very severe disturbances and blackouts. In a screening stage we form an optimization problem to find the minimum change in the network to move the power flow feasibility boundary to the present operating point and that will cause the system to separate with a user-specified power imbalance. The lines identified by the optimization program are used in a subsequent ...

  11. The influence of accident measures on accident scenarios for VVER-1000-Type reactors

    International Nuclear Information System (INIS)

    For VVER-1000-type reactors severe accident scenarios and possible mitigation strategies are investigated. The Station blackout sequence is chosen as reference case. At first a comparison between the cases with and without working spray systems is discussed. Afterwards the results of a parametric study investigating the influence of different water volumes on the course of the accident are presented. It can be shown that most of these accident mitigation measures will maintain the containment integrity and reduce the source term. (author)

  12. Prospective and Efficient Techniques for Model Reduction in Reliability Calculations

    OpenAIRE

    Pedersen, Robert Fossmark

    2013-01-01

    A reliable electric power supply is essential for modern society. Recently, severe blackouts worldwide have attracted attention to reliability studies in power system planning and operation. The relevance of the traditional N-1 criterion has been discussed, and much focus has been directed towards developing satisfactory probability based reliability tools. Goodtech Project & Services has developed a methodology for calculation of online power delivery reliability for use in power system ...

  13. Glaze Icing on Superhydrophobic Coating Prepared by Nanoparticles Filling Combined with Etching Method for Insulators

    OpenAIRE

    Chao Guo; Ruijin Liao; Yuan Yuan; Zhiping Zuo; Aoyun Zhuang

    2015-01-01

    Icing on insulators may cause flashover or even blackout accidents in the power transmission system. However, there are few anti-icing techniques for insulators which consume energy or manpower. Considering the water repelling property, the superhydrophobic surface is introduced for anti-icing of insulators. Among the icing forms, the glaze icing owns the highest density, strongest adhesion, and greatest risk to the power transmission system but lacks researches on superhydrophobic surface. I...

  14. Reducing the Vulnerability of Electric Power Grids to Terrorist Attacks

    Energy Technology Data Exchange (ETDEWEB)

    Ross Baldick; Thekla Boutsika; Jin Hur; Manho Joung; Yin Wu; Minqi Zhong

    2009-01-31

    This report describes the development of a cascading outage analyzer that, given an initial disturbance on an electric power system, checks for thermal overloads, under-frequency and over-frequency conditions, and under-voltage conditions that would result in removal of elements from the system. The analyzer simulates the successive tripping of elements due to protective actions until a post-event steady state or a system blackout is reached.

  15. Solar storms; Tormentas solares

    Energy Technology Data Exchange (ETDEWEB)

    Collaboration: Pereira Cuesta, S.; Pereira Pagan, B.

    2016-08-01

    Solar storms begin with an explosion, or solar flare, on the surface of the sun. The X-rays and extreme ultraviolet radiation from the flare reach the Earths orbit minutes later-travelling at light speed. The ionization of upper layers of our atmosphere could cause radio blackouts and satellite navigation errors (GPS). Soon after, a wave of energetic particles, electrons and protons accelerated by the explosion crosses the orbit of the Earth, and can cause real and significant damage. (Author)

  16. Importance Sampling Based Decision Trees for Security Assessment and the Corresponding Preventive Control Schemes: the Danish Case Study

    OpenAIRE

    Liu, Leo; Rather, Zakir Hussain; Chen, Zhe; Bak, Claus Leth; Thøgersen, Paul

    2013-01-01

    Decision Trees (DT) based security assessment helps Power System Operators (PSO) by providing them with the most significant system attributes and guiding them in implementing the corresponding emergency control actions to prevent system insecurity and blackouts. DT is obtained offline from time-domain simulation and the process of data mining, which is then implemented online as guidelines for preventive control schemes. An algorithm named Classification and Regression Trees (CART) is used t...

  17. Adaptive Tuning of Frequency Thresholds Using Voltage Drop Data in Decentralized Load Shedding

    OpenAIRE

    Hoseinzadeh, Bakhtyar; Faria Da Silva, Filipe Miguel; Bak, Claus Leth

    2015-01-01

    Load shedding (LS) is the last firewall and the most expensive control action against power system blackout. In the conventional under frequency LS (UFLS) schemes, the load drop locations are already determined independently of the event location. Furthermore, the frequency thresholds of LS relays are prespecified and constant values which may not be a comprehensive solution for widespread range of possible events. This paper addresses the decentralized LS in which the instantaneous voltage d...

  18. Optimal UPFC placement in Isfahan-Khozestan transmission network by using APSO algorithm for improving transient stability

    OpenAIRE

    Y. Rezaee; A. Khodabakhshian; M. Moazzami

    2012-01-01

    Today power system works with a lower stability boundary due to increasing energy consumption. Increase of extensive blackouts in different points of the world in recent years clarifies that the power system stability should be improved. Using FACTS devices has a great role for improving power system stability. In this regard, locating UPFC in order to boost stability is getting important in power system studies. This paper develops a new optimal UPFC placement method by using adaptive PSO ...

  19. Vulnerability of electricity transmission infrastructure to natural hazards

    Science.gov (United States)

    Komendantova, Nadejda

    2016-04-01

    Electricity transmission system is a very complex system, which consists of several elements, such as overhead lines, substations and transformers, covers wide areas, is interconnected with several networks with numerous inter-dependencies. This highly integrated system is exposed to several hazards, leading to interruption of power supply. Natural hazards, such as an increased frequency of extreme weather events, including storms, icing, wet snow deposits, lighting, floods, avalanches, rock falls and landslides or changing air temperature have effects on transmission and lead to destruction of this infrastructure, which is also critical for society as it guarantees functioning of vital for society services. The reliability of critical electricity transmission infrastructure depends on its ability to ensure normal operation, to limit number of incidents and to avoid major incidents and to limit consequences of major incidents. The concept of reliability is closely connected with the concept of resilience, which is understood, in general, as the ability of a system to react and recover from anticipated disturbances and events. In regards to electricity transmission resilience is the ability of the power system to adapt, self-organize and recover or achieve the level even higher than those before the shock. This paper reviews three major natural hazards disasters, which resulted in significant blackouts in Europe. The first one is the 2003 blackout in Italy, which was caused by flash-over from trees. The second one is the 2003 blackout in Sweden, which was caused by rainstorms. The third one is the 2005 blackout in Germany, which was caused by wet snow. The inter-comparative analysis of these events allowed us to develop recommendations on electricity transmission network resilience.

  20. Understanding the cost of power interruptions to U.S. electricity consumers

    OpenAIRE

    LaCommare, Kristina Hamachi; Eto, Joseph H.

    2004-01-01

    The massive electric power blackout in the northeastern United States and Canada on August 14-15, 2003 resulted in the U.S. electricity system being g called "antiquated" and catalyzed discussions about modernizing the grid. Industry sources suggested that investments of $50 to $100 billion would be needed. This report seeks to quantify an important piece of information that has been missing from these discussions: how much do power interruptions and fluctuations in power quality (power...

  1. Power Outage - 16 October

    CERN Multimedia

    2014-01-01

    At 19:03 last night, a fire in an 18kV circuit breaker in building 212 led to a blackout on the Meyrin site. The CERN fire brigade rapidly brought the fire under control and power was restored by 22:25. Many CERN systems were affected and have been brought back in to service overnight, this work will continue through the day.

  2. Comparison of Severe Accident Results Among SCDAP/RELAP5, MAAP, and MELCOR Codes

    International Nuclear Information System (INIS)

    This paper demonstrates a large-break loss-of-coolant accident (LOCA) sequence of the Kuosheng nuclear power plant (NPP) and station blackout sequence of the Maanshan NPP with the SCDAP/RELAP5 (SR5), Modular Accident Analysis Program (MAAP), and MELCOR codes. The large-break sequence initiated with double-ended rupture of a recirculation loop. The main steam isolation valves (MSIVs) closed, the feedwater pump tripped, the reactor scrammed, and the assumed high-pressure and low-pressure spray systems of the emergency core cooling system (ECCS) were not functional. Therefore, all coolant systems to quench the core were lost. MAAP predicts a longer vessel failure time, and MELCOR predicts a shorter vessel failure time for the large-break LOCA sequence. The station blackout sequence initiated with a loss of all alternating-current (ac) power. The MSIVs closed, the feedwater pump tripped, and the reactor scrammed. The motor-driven auxiliary feedwater system and the high-pressure and low-pressure injection systems of the ECCS were lost because of the loss of all ac power. It was also assumed that the turbine-driven auxiliary feedwater pump was not functional. Therefore, the coolant system to quench the core was also lost. MAAP predicts a longer time of steam generator dryout, time interval between top of active fuel and bottom of active fuel, and vessel failure time than those of the SR5 and MELCOR predictions for the station blackout sequence. The three codes give similar results for important phenomena during the accidents, including SG dryout, core uncovery, cladding oxidation, cladding failure, molten pool formulation, debris relocation to the lower plenum, and vessel head failure. This paper successfully demonstrates the large-break LOCA sequence of the Kuosheng NPP and the station blackout sequence of the Maanshan NPP

  3. Do Conditional Reinforcers Count?

    OpenAIRE

    Davison, Michael; Baum, William M.

    2006-01-01

    Six pigeons were trained on a procedure in which seven components arranged different food-delivery ratios on concurrent variable-interval schedules each session. The components were unsignaled, lasted for 10 food deliveries, and occurred in random order with a 60-s blackout between components. The schedules were arranged using a switching-key procedure in which two responses on a center key changed the schedules and associated stimuli on two side keys. In Experiment 1, over five conditions, a...

  4. Contribution of Water Saving to a Stable Power Supply in Vietnam

    Directory of Open Access Journals (Sweden)

    Takayuki Otani

    2015-06-01

    Full Text Available In Vietnam, the rapid expansion of cities is exceeding the supply capacity for water and electricity, and restrictions on water supply and blackouts occur on a daily basis. In this study, the authors examined whether water-saving equipment could solve these problems. This paper focused on toilet bowls that consumed a large amount of water, and on showers for which heat consumption was high. In Vietnam, the main heat source for showers is the electric water heater, typically having a power consumption of 2500–4500 W. Although the current diffusion rate of such water heaters is just 13%, their use will spread widely in the future. These heaters have already placed a peak load on electricity consumption in winter when a large amount of energy is consumed for heating water, and they will become a significant factor in blackout risks as their use becomes commonplace nationwide. It is clear that the introduction of water-saving showers will allow not only a more efficient use of water resources, but will also mitigate against the risk of blackouts.

  5. Improving Power System Risk Evaluation Method Using Monte Carlo Simulation and Gaussian Mixture Method

    Directory of Open Access Journals (Sweden)

    GHAREHPETIAN, G. B.

    2009-06-01

    Full Text Available The analysis of the risk of partial and total blackouts has a crucial role to determine safe limits in power system design, operation and upgrade. Due to huge cost of blackouts, it is very important to improve risk assessment methods. In this paper, Monte Carlo simulation (MCS was used to analyze the risk and Gaussian Mixture Method (GMM has been used to estimate the probability density function (PDF of the load curtailment, in order to improve the power system risk assessment method. In this improved method, PDF and a suggested index have been used to analyze the risk of loss of load. The effect of considering the number of generation units of power plants in the risk analysis has been studied too. The improved risk assessment method has been applied to IEEE 118 bus and the network of Khorasan Regional Electric Company (KREC and the PDF of the load curtailment has been determined for both systems. The effect of various network loadings, transmission unavailability, transmission capacity and generation unavailability conditions on blackout risk has been investigated too.

  6. A FMM-FFT accelerated hybrid volume surface integral equation solver for electromagnetic analysis of re-entry space vehicles

    KAUST Repository

    Yücel, Abdulkadir C.

    2014-07-01

    Space vehicles that re-enter the atmosphere often experience communication blackout. The blackout occurs when the vehicle becomes engulfed in plasma produced by interactions between the vehicle surface and the atmosphere. The plasma often is concentrated in a relatively thin shell around the vehicle, with higher densities near its nose than rear. A less structured, sometimes turbulent plasma wake often trails the vehicle. The plasma shell severely affects the performance of side-mounted antennas as it alters their characteristics (frequency response, gain patterns, axial ratio, and impedance) away from nominal, free-space values, sometimes entirely shielding the antenna from the outside world. The plasma plume/turbulent wake similarly affect the performance of antennas mounted at the back of the vehicle. The electromagnetic characteristics of the thin plasma shell and plume/turbulent wake heavily depend on the type of re-entry trajectory, the vehicle\\'s speed, angles of attack, and chemical composition, as well as environmental conditions. To analyze the antennas\\' performance during blackout and to design robust communication antennas, efficient and accurate simulation tools for charactering the antennas\\' performance along the trajectory are called for.

  7. Conceptual design of passive containment cooling system based on APR+

    International Nuclear Information System (INIS)

    The accident of the Fukushima nuclear power plant left a profound message toward the need for a passive cooling system which can operate under the extended station blackout. These days, nuclear institutions in Korea are developing Advanced Power Reactor Plus (APR+). Its distinct characteristic lies on the passive auxiliary feed water system (PAFS) which removes decay heat to a passive condensation cooling tank (PCCT) by natural convection. Though the system is expected to work well under station blackout, the system becomes useless under the loss of coolant accident (LOCA) combined with station blackout. This paper aims at using existing heat exchangers of PAFS and PCCT under LOCA to cool the reactor as well as the containment in a fully passive way. To enhance the condensation rate of heat exchangers in PCCT, we need to produce convective flow in the PCCS heat exchangers. Therefore, the whole region of the concrete containment is divided into 3 chambers: inner, outer, PCCS chambers. An outer chamber is disposed to collect non-condensable gas. The condensate is stored in a condensate storage tank (CST) and injected into the reactor by gravity. This system makes a closed circuit to work indefinitely. A scoping analysis for the containment pressure is performed as a function of various parameters: outer chamber volume and number of tubes in heat exchangers. (author)

  8. Concept of a self-sustaining cooling system for after-heat removal in BWR-type reactors; Konzept eines autarken Kuehlsystems zur Nachwaermeabfuhr in Siedewasserreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Venker, J. [RWE Technology GmbH, Essen (Germany). Nukleartechnologie; Stuttgart Univ. (Germany). Inst. fuer Kernenergetik und Energiesysteme (IKE); Lavante, D. von [TUEV Rheinland, Koeln (Germany); Buck, M.; Starflinger, J. [Stuttgart Univ. (Germany). Inst. fuer Kernenergetik und Energiesysteme (IKE); Gitzel, D. [RWE Technology GmbH, Essen (Germany). Nukleartechnologie

    2013-07-01

    The concept, technical feasibility and potential capability of a new self-sustaining after-heat removal system based on supercritical carbon dioxide is described. The effect of the system on the plant behavior of appropriately retrofitted BWR-type reactors is discussed. Based on calculations using the thermal hydraulic code ATHLET it is shown that the safe after-heat removal time of existing BWR-type reactors in case of station blackout can be increased for several hours. The calculations have also shown that a enduring control of the station blackout situation cannot be reached by the retrofitting of the pressure relief system. The question is raised whether the pressure relief is reasonable independent of the accident scenario. Without the possibility of further coolant supply in case of station blackout the pressure relief will enhance the dry-out of the reactor core. The high-pressure path for the primary circuit increases the time for possible external measures to activate ECCS or active after-heat removal.

  9. Application of Advanced Wide Area Early Warning Systems with Adaptive Protection

    Energy Technology Data Exchange (ETDEWEB)

    Blumstein, Carl [Univ. of California, Berkeley, CA (United States); Cibulka, Lloyd [Univ. of California, Berkeley, CA (United States); Thorp, James [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Centeno, Virgilio [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); King, Roger [Mississippi State Univ., Mississippi State, MS (United States); Reeves, Kari [Mississippi State Univ., Mississippi State, MS (United States); Ashrafi, Frank [Southern California Edison Co., Rosemead, CA (United States); Madani, Vahid [Pacific Gas & Electric Co., San Francisco, CA (United States)

    2014-09-30

    Recent blackouts of power systems in North America and throughout the world have shown how critical a reliable power system is to modern societies, and the enormous economic and societal damage a blackout can cause. It has been noted that unanticipated operation of protection systems can contribute to cascading phenomena and, ultimately, blackouts. This project developed and field-tested two methods of Adaptive Protection systems utilizing synchrophasor data. One method detects conditions of system stress that can lead to unintended relay operation, and initiates a supervisory signal to modify relay response in real time to avoid false trips. The second method detects the possibility of false trips of impedance relays as stable system swings “encroach” on the relays’ impedance zones, and produces an early warning so that relay engineers can re-evaluate relay settings. In addition, real-time synchrophasor data produced by this project was used to develop advanced visualization techniques for display of synchrophasor data to utility operators and engineers.

  10. Improving the Transmission System Reliability for the 154kV Radial Network Operation

    Energy Technology Data Exchange (ETDEWEB)

    Choo, Jin Boo; Yoo, Myeong Ho; Yoon, Young Beum; Kim, Tae Won [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Lee, Gi Won; Chung, Beom Jin; Jung, Jung Won; Park, Kyu Hyun; Lee, Myung Hee; Kim, Hyun Jong; Kim, Chae Hee [KEYIN CO., (Korea, Republic of)

    1996-12-31

    Analyzing that 154kV radial network current ed operated, we developed Automatic Power Reconfiguration System(APRS) which restore blackout area. It consists of special data acquisition system(DAU) and central monitoring system for reason of protecting currently operating power system. In addition, it communicates using optical communication network for high speed data transmission and accuracy. An Accuracy of operation and stability of the developed system is tested using Real Time Digital Simulator in 3-bus equivalent model system. In An Outage case, our developed system can restore a blackout area in three second. An ability of the restoration of a blackout was verified by simulations. For the field test, the developed system was set up at SINCHON S/S, SESOMUN S/S, SINDANG S/S and MAJANG S/S governed by Seoul Power Transmission Center. If the system reliability is proved for a one year test in real power system, application of the system will be extended to the other substations.

  11. Salvia miltiorrhiza Bunge Blocks Ethanol-Induced Synaptic Dysfunction through Regulation of NMDA Receptor-Dependent Synaptic Transmission.

    Science.gov (United States)

    Park, Hye Jin; Lee, Seungheon; Jung, Ji Wook; Lee, Young Choon; Choi, Seong-Min; Kim, Dong Hyun

    2016-07-01

    Consumption of high doses of ethanol can lead to amnesia, which often manifests as a blackout. These blackouts experienced by ethanol consumers may be a major cause of the social problems associated with excess ethanol consumption. However, there is currently no established treatment for preventing these ethanol-induced blackouts. In this study, we tested the ethanol extract of the roots of Salvia miltiorrhiza (SM) for its ability to mitigate ethanol-induced behavioral and synaptic deficits. To test behavioral deficits, an object recognition test was conducted in mouse. In this test, ethanol (1 g/kg, i.p.) impaired object recognition memory, but SM (200 mg/kg) prevented this impairment. To evaluate synaptic deficits, NMDA receptor-mediated excitatory postsynaptic potential (EPSP) and long-term potentiation (LTP) in the mouse hippocampal slices were tested, as they are known to be vulnerable to ethanol and are associated with ethanol-induced amnesia. SM (10 and 100 μg/ml) significantly ameliorated ethanol-induced long-term potentiation and NMDA receptor-mediated EPSP deficits in the hippocampal slices. Therefore, these results suggest that SM prevents ethanol-induced amnesia by protecting the hippocampus from NMDA receptor-mediated synaptic transmission and synaptic plasticity deficits induced by ethanol. PMID:27257009

  12. RBMK-1500 accident management for loss of long-term core cooling

    International Nuclear Information System (INIS)

    Results of the Level 1 probabilistic safety assessment of the Ignalina NPP has shown that in topography of the risk, transients dominate above the accidents with LOCAs and failure of the core long-term cooling are the main factors to frequency of the core damage. Previous analyses have shown, that after initial event, as a rule, the reactivity control, as well as short-term and intermediate cooling are provided. However, the acceptance criteria of the long-term cooling are not always carried out. It means that from this point of view the most dangerous accident scenarios are the scenarios related to loss of the core long-term cooling. On the other hand, the transition to the core condition due to loss of the long-term cooling specifies potential opportunities for the management of the accident consequences. Hence, accident management for the mitigation of the accident consequences should be considered and developed. The most likely initiating event, which probably leads to the loss of long term cooling accident, is station blackout. The station blackout is the loss of normal electrical power supply for local needs with an additional failure on start-up of all diesel generators. In the case of loss of electrical power supply MCPs, the circulating pumps of the service water system and MFWPs are switched-off. At the same time, TCV of both turbines are closed. Failure of diesel generators leads to the non-operability of the ECCS long-term cooling subsystem. It means the impossibility to feed MCC by water. The analysis of the station blackout for Ignalina NPP was performed using RELAP5 code. (author)

  13. Ontario-U.S. power outages : impacts on critical infrastructure

    International Nuclear Information System (INIS)

    This paper described the power outage and resulting blackout that occurred on August 14, 2003 and identified how critical infrastructure was directly and interdependently impacted in Canada. The aim of the paper was to assist critical infrastructure protection and emergency management professionals in assessing the potential impacts of large-scale critical infrastructure disruptions. Information for the study was acquired from Canadian and American media reports and cross-sectoral information sharing with provincial and federal governments and the private sector. The blackout impacted most of the sources and means of generating, transmitting and distributing power within the area, which in turn impacted all critical infrastructure sectors. Landline and cellular companies experienced operational difficulties, which meant that emergency responders were impacted. Newspapers and the electronic media struggled to release information to the public. The banking and finance industry experienced an immediate degradation of services. The power outage caused shipping and storage difficulties for commercial retailers and dairy producers. A number of incidents were reported where only partially treated waste water was released into neighbouring waterways. The timing of the blackout coincided with the closures of workplaces and created additional difficulties on transportation networks. Many gas station pumps were inoperable. Police, fire departments and ambulance services experienced a dramatic increase in the volume of calls received, and all branches of the emergency services sector encountered transportation delays and difficulties with communications equipment. Nuclear reactors were also impacted. An estimated 150,000 Government of Canada employees were unable to report to work. Estimates have indicated that the power outage cost Ontario's economy between $1 and $2 billion. The outage negatively impacted 82 per cent of small businesses in Ontario. 170 refs., 3 figs

  14. Laser technologies for on-site surveillance

    International Nuclear Information System (INIS)

    There are situations, where video surveillance based on automated scene change detection systems may prove to be ineffective. In some cases, the changes in the image are too small to be properly detected. In others, false alarms are generated without objects (or people) moving. These alarms may be caused by changes in illumination, e.g., a faulty lamp or spurious reflections in places near water pools. Further, the absence of illumination during a blackout (whether it is caused by accident or on purpose) prevents cameras from their surveillance operation. There are high security installations for which it is necessary to introduce reliable, independent and effective sensors that can keep the surveillance work even during a blackout. Laser range scanners are electronic instruments measuring the distance from the instrument itself to the outside world along a specific direction. The type of the instrument to use depends on the range of distances to measure. The deflection of the laser beam (e.g., using a rotating mirror) enables the acquisition of the distance profiles of the surrounding premises in a very short time. Alarms are generated by comparing acquired distance measurements (organized as profiles - 2D Laser Surveillance, or in clouds of points - 3D Laser Surveillance) with previously acquired references. This is most effective for real-time detection of even small changes in the environment. The main feature of laser surveillance system is that it measures distances between the instrument itself and the real world, rather than measuring only appearance as video surveillance systems do. As such, any physical change occurring within the field of site of the laser instrument is immediately measured and detected. The fact that laser systems are self-illuminating and do not depend on the external illumination make them quite effective to work during blackouts. The paper introduces laser surveillance and shows how such systems complement well already existing video

  15. Radionuclide release calculations for selected severe accident scenarios

    International Nuclear Information System (INIS)

    This report provides the results of source term calculations that were performed in support of the NUREG-1150 study. ''Severe Accident Risks: An Assessment for Five US Nuclear Power Plants.'' This is the sixth volume of a series of reports. It supplements results presented in the earlier volumes. Analyses were performed for three of the NUREG-1150 plants: Peach Bottom, a Mark I, boiling water reactor; Surry, a subatmospheric containment, pressurized water reactor; and Sequoyah, an ice condenser containment, pressurized water reactor. Complete source term results are presented for the following sequences: short term station blackout with failure of the ADS system in the Peach Bottom plant; station blackout with a pump seal LOCA for the Surry plant; station blackout with a pump seal LOCA in the Sequoyah plant; and a very small break with loss of ECC and spray recirculation in the Sequoyah plant. In addition, some partial analyses were performed which did not require running all of the modules of the Source Term Code Package. A series of MARCH3 analyses were performed for the Surry and Sequoyah plants to evaluate the effects of alternative emergency operating procedures involving primary and secondary depressurization on the progress of the accident. Only thermal-hydraulic results are provided for these analyses. In addition, three accident sequences were analyzed for the Surry plant for accident-induced failure of steam generator tubes. In these analyses, only the transport of radionuclides within the primary system and failed steam generator were examined. The release of radionuclides to the environment is presented for the phase of the accident preceding vessel meltthrough. 17 refs., 176 figs., 113 tabs

  16. The propagation characteristics of electromagnetic waves through plasma in the near-field region of low-frequency loop antenna

    Science.gov (United States)

    Liu, DongLin; Li, XiaoPing; Xie, Kai; Liu, ZhiWei

    2015-10-01

    A high-speed vehicle flying through the atmosphere between 100 and 20 km may suffer from a "communication blackout." In this paper, a low frequency system with an on-board loop antenna to receive signals is presented as a potential blackout mitigation method. Because the plasma sheath is in the near-field region of the loop antenna, the traditional scattering matrix method that is developed for the far-field region may overestimate the electromagnetic (EM) wave's attenuation. To estimate the EM wave's attenuation in the near-field region, EM interference (EMI) shielding theory is introduced. Experiments are conducted, and the results verify the EMI shielding theory's effectiveness. Simulations are also conducted with different plasma parameters, and the results obtained show that the EM wave's attenuation in the near-field region is far below than that in the far-field region. The EM wave's attenuation increases with the increase in electron density and decreases with the increase in collision frequency. The higher the frequency, the larger is the EM wave's attenuation. During the entire re-entry phase of a RAM-C module, the EM wave's attenuations are below 10 dB for EM waves with a frequency of 1 MHz and below 1 dB for EM waves with a frequency of 100 kHz. Therefore, the low frequency systems (e.g., Loran-C) may provide a way to transmit some key information to high-speed vehicles even during the communication "blackout" period.

  17. Probabilistic Assessment of Grid Disturbance Initiating Events

    International Nuclear Information System (INIS)

    Level-1 PSA of Kakrapar Atomic Power Station, an Indian PHWR, covering the internal initiating events is in progress. As part of this study, event tree analysis is taken up for the initiating event involving offsite power supply failure resulting due to grid disturbance, to analyze the various event sequences. Station Blackout is one of the scenarios analysed in this event tree. A recovery possibility of Class-III Power Supply is also postulated, failure of which is assumed to lead to an extended Station Blackout situation. The performance required of each function event/frontline system depends on both the initiators and the additional system failures or successes in a particular accident sequence. Hence, different definitions of success criteria and boundary conditions are identified accordingly for the various frontline system fault tree modelling. The concept of small evet tree and large fault tree is adopted. To identify the dominant Common Cause Failure (CCF) vulnerabilities, a detailed CCF analysis is carried out. Appropriate human error probabilities are used after giving due credit to performance shaping factors, emergency operating procedures and O and M checklists. Plant specific failure parameters are computed and Bayesian technique is used to calculate the posterior values. Subsequent to accident sequence quantification, importance analysis is carried out to determine the important accident sequences, system failures, component failures and human errors. It was observed that in spite of high frequency of grid disturbances, the onsite power supply (we have three Diesel Generators and one Diesel Generator is sufficient to cater to safety loads) is highly reliable and the frequency of core damage / Station Blackout is very low. (author)

  18. The Electric Systems and their success in 2003; Los sistemas electricos y sus incidencias en 2003

    Energy Technology Data Exchange (ETDEWEB)

    Modeen, D.

    2004-07-01

    The first question, as it relates to the reliability and the stability of the grid, is: Are nuclear power plants part of the problem or part of the solution?. And, the second is: do we need to do anything different going forward?. This presentation is broken into four areas: - Effect of the grid reliability in the U. S. based on the experiences of loss of offsite power to our nuclear power plants - The impact of deregulation (started in 1992) on the nuclear power plant - The blackout and the conditions that led to it - How the nuclear power plants responded Since 1980, the United States has seen a decrease of Loss of Offsite Power (Loop) cases in the vicinity of our nuclear power plant. The reasons among others are: - Improved infrastructures, more transmission lines, more switchyards. - More breakers and shorter distances mean reduced exposure to a problem. - There are more parallel ways between two given points. - Failures of key equipment in power stations have continued to decrease. Compilation of operating experience data, that is analyzed by both EPRI and NRC (coming from a 20-plus year long EPRI data base), showers a 2 to 3% chance per plant per year of a LOOP. This is consisted with the experience of more than 100 nuclear units in the last t years prior to the blackout Specifically, in 2002 there were no events and in 2003 two events occurred before the blackout. The effects of the restricting of the U. S. electricity industry (in some regions) as it relates to the interface of the grid with the nuclear power plants operator are that: - Some owners of nuclear power plants no longer own and maintain their plants? switchyards - There are discrepancies in the appreciation of the importance that these facilities have for the nuclear power plants - There have been preventable failures in breakers and relays. (Author)

  19. Radionuclide release calculations for selected severe accident scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Denning, R.S.; Leonard, M.T.; Cybulskis, P.; Lee, K.W.; Kelly, R.F.; Jordan, H.; Schumacher, P.M.; Curtis, L.A. (Battelle Columbus Div., OH (USA))

    1990-08-01

    This report provides the results of source term calculations that were performed in support of the NUREG-1150 study. Severe Accident Risks: An Assessment for Five US Nuclear Power Plants.'' This is the sixth volume of a series of reports. It supplements results presented in the earlier volumes. Analyses were performed for three of the NUREG-1150 plants: Peach Bottom, a Mark I, boiling water reactor; Surry, a subatmospheric containment, pressurized water reactor; and Sequoyah, an ice condenser containment, pressurized water reactor. Complete source term results are presented for the following sequences: short term station blackout with failure of the ADS system in the Peach Bottom plant; station blackout with a pump seal LOCA for the Surry plant; station blackout with a pump seal LOCA in the Sequoyah plant; and a very small break with loss of ECC and spray recirculation in the Sequoyah plant. In addition, some partial analyses were performed which did not require running all of the modules of the Source Term Code Package. A series of MARCH3 analyses were performed for the Surry and Sequoyah plants to evaluate the effects of alternative emergency operating procedures involving primary and secondary depressurization on the progress of the accident. Only thermal-hydraulic results are provided for these analyses. In addition, three accident sequences were analyzed for the Surry plant for accident-induced failure of steam generator tubes. In these analyses, only the transport of radionuclides within the primary system and failed steam generator were examined. The release of radionuclides to the environment is presented for the phase of the accident preceding vessel meltthrough. 17 refs., 176 figs., 113 tabs.

  20. Study on depressurization measurements and effect in PWR

    International Nuclear Information System (INIS)

    Implementation of new regulations on nuclear powered plant design and operation raise new design and management requirement for plants, and the operational plants also need accident management to enhance the reactor operation safety. Thus, for sake of reducing risk of high-pressure and mitigating the consequence, depressurization is a measure carried out to reduce primary pressure. With SCDAP/RELAP5 this paper studies the depressurization measurements and effect factors in pressurized water reactor under the important severe accident sequences induced by very small break lost of coolant accident (VSBLOCA), anticipated transient without scram (ATWS) and station blackout (SBO) plus auxiliary feedwater failure. (author)

  1. Probabilistic consequence analysis of ATWSs in a PWR plant

    International Nuclear Information System (INIS)

    PWR responses (in terms of overpressures, DNBR and other safety-related quantities) to ATWSs are being probabilistically investigated by applying response surface methodology to ALMOD, a computer program for simulation of large amplitude transients. The reactor considered for the analysis is the 1300 MWel reference KWU reactor plant. A comprehensive set of input quantities--including operational, engineering and physical variables--is taken into account. Results are presented for the first phases of station-blackout and loss-of-heat sink ATWSs

  2. Transient analysis passive emergency feedwater system of CPR1000

    International Nuclear Information System (INIS)

    The transient thermal hydraulic characteristics of CPR1000 were analyzed by using RELAP5/MOD 3.4 code to verify the capability of the passive emergency feedwater system (PEFWS) for accident mitigation under the condition of station blackout accident (SBO). The calculation results show that the PEFWS of CPR1000 can supply the water to steam generator immediately and remove the core residual heat after the SBO successfully, and it also shows that the design of the PEFWS of CPR1000 is successful. (authors)

  3. Ailing uranium millworkers seek recognition, aid

    International Nuclear Information System (INIS)

    Uranium millworkers who helped produce uranium for the U.S. nuclear defense program in the 1950's and 1960's are suing the federal government and uranium companies for compensation for illnesses that they believe are job-related. Symptoms of these illnesses include frequent blackouts, chronic bronchitis, asthma, constant fatigue, and susceptibility to colds. Research is being conducted to determine whether the millworkers' symptoms are due to excessive radiation exposure. Studies to date indicated that during the 1950's and early 1960's, radiation protection procedures at uranium milling facilities were extremely deficient

  4. Early results of microwave transmission experiments through an overly dense rectangular plasma sheet with microparticle injection

    International Nuclear Information System (INIS)

    These experiments utilize a linear hollow cathode to create a dense, rectangular plasma sheet to simulate the plasma layer surrounding vehicles traveling at hypersonic velocities within the Earth's atmosphere. Injection of fine dielectric microparticles significantly reduces the electron density and therefore lowers the electron plasma frequency by binding a significant portion of the bulk free electrons to the relatively massive microparticles. Measurements show that microwave transmission through this previously overly dense, impenetrable plasma layer increases with the injection of alumina microparticles approximately 60 μm in diameter. This method of electron depletion is a potential means of mitigating the radio communications blackout experienced by hypersonic vehicles

  5. Start-up of a power unit of a thermal power plant auxiliary system with supply from a hydropower plant

    OpenAIRE

    Zbigniew Lubośny; Krzysztof Dobrzyński; Jacek Klucznik

    2013-01-01

    This article discusses the issues related to a power unit of a thermal power plant start-up with the use of a hydropower plant. Hydropower plant can supply and will enable start-up of auxiliary equipment in a power unit of a thermal power plant. Due to high capacity of auxiliary drives, startup of auxiliaries in a thermal power plant after blackout (and boiler shutdown) is not possible from emergency energy sources in the power plant. In such a case an external electricity source with high ca...

  6. Thermal-hydraulic analyses of transients in an actinide-burner reactor cooled by forced convection of lead-bismuth

    International Nuclear Information System (INIS)

    The Idaho National Engineering and Environmental Laboratory (INEEL) and the Massachusetts Institute of Technology (MIT) are investigating the suitability of lead or lead-bismuth cooled fast reactors for producing low-cost electricity as well as for actinide burning. The current analysis evaluated a pool type design that relies on forced circulation of the primary coolant, a conventional steam power conversion system, and a passive decay heat removal system. The ATHENA computer code was used to simulate various transients without reactor scram, including a primary coolant pump trip, a station blackout, and a step reactivity insertion. The reactor design successfully met identified temperature limits for each of the transients analyzed

  7. Battery Electric Vehicles can reduce greenhouse has emissions and make renewable energy cheaper in India

    Energy Technology Data Exchange (ETDEWEB)

    Gopal, Anand R [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Witt, Maggie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sheppard, Colin [Humboldt State Univ., Arcata, CA (United States); Harris, Andrew [Humboldt State Univ., Arcata, CA (United States)

    2015-07-01

    India's National Mission on Electric Mobility (NMEM) sets a countrywide goal of deploying 6 to 7 million hybrid and electric vehicles (EVs) by 2020. There are widespread concerns, both within and outside the government, that the Indian grid is not equipped to accommodate additional power demand from battery electric vehicles (BEVs). Such concerns are justified on the grounds of India's notorious power sector problems pertaining to grid instability and chronic blackouts. Studies have claimed that deploying BEVs in India will only

  8. Verification of voltage/ frequency requirement for emergency diesel generator in nuclear power plant using dynamic modeling

    International Nuclear Information System (INIS)

    Full-text: One major cause of the plant shutdown is the loss of electrical power. The study is to comprehend the coping action against station blackout including emergency diesel generator, sequential loading of safety system and to ensure that the emergency diesel generator should meet requirements, especially voltage and frequency criteria using modeling tool. This paper also considered the change of the sequencing time and load capacity only for finding electrical design margin. However, the revision of load list must be verified with safety analysis. From this study, it is discovered that new load calculation is a key factor in EDG localization and in-house capability increase. (author)

  9. Using dynamic mains models in grid-planning and operation

    International Nuclear Information System (INIS)

    This article presents and discusses scenarios for re-creating three separate islands in the Swiss electricity grid after a blackout. The dangers presented by long-distance energy transport and situations encountered when interruptions along the transit corridors occur are looked at. The increasing number of interfaces between market players in the liberalised electricity market and the co-ordination problems thus arising are discussed. The development of models for the increasingly dynamic operation of power generation and transport facilities is discussed. A list of the various types of generation facilities involved is presented. The necessary control parameters for the operation of the power islands are discussed

  10. Reducing the risk of cyber threats in utilities through log management

    Energy Technology Data Exchange (ETDEWEB)

    Patnaik, A. [ArcSight, Cupertino, CA (United States)

    2010-01-15

    Electrical blackouts caused by terrorists hacking into targeted control systems have already occurred in Brazil. A patchwork of security tools is needed to reduce potential threats. The continuous collection and analysis of data is also needed to detect cyber threats. The real time correlation of logs across all systems, applications and users is needed to ensure the reliability and security of the power grid. Solutions must also integrate well with identity management sources in order to prevent remote access account hijacking. Effective log management can be used to detect threats and reduce the risk of power outages. 1 fig.

  11. Delayed matching-to-sample performance: Effects of relative reinforcer frequency and of signaled versus unsignaled reinforcer magnitudes

    OpenAIRE

    McCarthy, Dianne; Voss, Philip

    1995-01-01

    Six pigeons were trained on a delayed red-green matching-to-sample task that arranged four delays within sessions. Matching responses intermittently produced either 1.5-s access to food or 4.5-s access to food, and nonmatching responses produced either 1.5-s or 4.5-s blackout. Two phases were conducted: a signaled phase in which the reinforcer magnitudes (small and large) were signaled by houselights (positioned either on the left or right of the chamber), and an unsignaled phase in which the...

  12. The X-33 Extended Flight Test Range

    Science.gov (United States)

    Mackall, Dale A.; Sakahara, Robert; Kremer, Steven E.

    1998-01-01

    Development of an extended test range, with range instrumentation providing continuous vehicle communications, is required to flight-test the X-33, a scaled version of a reusable launch vehicle. The extended test range provides vehicle communications coverage from California to landing at Montana or Utah. This paper provides an overview of the approaches used to meet X-33 program requirements, including using multiple ground stations, and methods to reduce problems caused by reentry plasma radio frequency blackout. The advances used to develop the extended test range show other hypersonic and access-to-space programs can benefit from the development of the extended test range.

  13. Risk Assessment of Power System Catastrophic Failures and Hidden Failure Monitoring & Control System

    OpenAIRE

    Qiu, Qun

    2003-01-01

    One of the objectives of this study is to develop a methodology, together with a set of software programs that evaluate, in a power system, the risks of catastrophic failures caused by hidden failures in the hardware or software components of the protection system. The disturbance propagation mechanism is revealed by the analysis of the 1977 New York Blackout. The step-by-step process of estimating the relay hidden failure probability is presented. A Dynamic Event Tree for the risk-based ana...

  14. Tidssynkroniserade mätningar i vattenkraftstationer

    OpenAIRE

    Larsson, Bertil

    2010-01-01

    Vattenfall and Svenska Kraftnät perform start-up tests, where hydropower generators are used to power up the electrical grid in case of a blackout. To monitor the electrical grid, Phasor Measurement Units (PMU) are used. Each PMU is individually equipped with a GPS-receiver to precisely timestamp the data relative to the official time UTC. During the test, it is also of interest to timestamp the measurement signals from individual hydropower generators to later compare with PMU-data, and thus...

  15. BWR/5 Pressure-Suppression Pool Response during an SBO

    OpenAIRE

    Javier Ortiz-Villafuerte; Andrés Rodríguez-Hernández; Enrique Araiza-Martínez; Luis Fuentes-Márquez; Jorge Viais-Juárez

    2013-01-01

    RELAP/SCDAPSIM Mod 3.4 has been used to simulate a station blackout occurring at a BWR/5 power station. Further, a simplified model of a wet well and dry well has been added to the NSSS model to study the response of the primary containment during the evolution of this accident. The initial event leading to severe accident was considered to be a LOOP with simultaneous scram. The results show that RCIC alone can keep the core fully covered, but even in this case about 30% of the original liqui...

  16. Detecting and mitigating inverter aging

    International Nuclear Information System (INIS)

    Nuclear power plants use inverters to supply power to safety-related equipment, instrumentation, and controls. They convert direct current (dc) to alternating current (ac) power, thereby making low voltage ac power available even under a station blackout condition. As part of the U.S. NRC's nuclear plant aging research (NPAR) program, the operating experience of this equipment has been analyzed to determine the dominant failure modes and causes. This paper summarizes that data, and then describes methods which can be employed to detect inverter degradation prior to failure, as well as methods to minimize the failure effects. In both cases, the mitigation of inverter aging is emphasized

  17. The integrated resource planning of the energy sector as a basis to water management in urban areas

    OpenAIRE

    Gilberto de Martino Jannuzzi; Ricardo da Silva Manca

    2008-01-01

    The Water Resources Planning in use doesn´t diverges substantially from the Traditional Energy Planning. With the energy crisis occurred at Brazil in 2001 the blackout possibility shows that the impact on the society might happen at any time. The same occurs to the water because of its scarcity. The Integrated Resource Planning (IRP) was diffused as a way of fully managing a resource by the supply and demand sizes and can be considerated a viable option for the conventional planning. This com...

  18. Multiagent System-Based Wide-Area Protection and Control Scheme against Cascading Events

    DEFF Research Database (Denmark)

    Liu, Zhou; Chen, Zhe; Sun, Haishun;

    2015-01-01

    strategy is defined to adjust the emergency states timely and prevent the unexpected relay trips. In order to supervise the control process and further minimize the load loss, an agent based process control is adopted to monitor the states of distributed controllers and adjust the emergency control...... strategy. A hybrid simulation platform based on LabVIEW and real time digital simulator (RTDS) is set up to simulate a blackout case in the power system of Eastern Denmark and to demonstrate the effectiveness of the proposed MAS based protection strategy....

  19. Severe accident analysis of a small LOCA accident using MAAP-CANDU support level 2 PSA for the Point Lepreau station refurbishment project

    International Nuclear Information System (INIS)

    A Level 2 Probabilistic Safety Assessment was performed for the Point Lepreau Generating Station. The MAAP4-CANDU code was used to calculate the progression of postulated severe core damage accidents and fission product releases. Five representative severe core damage accidents were selected: Station Blackout, Small Loss-of-Coolant Accident, Stagnation Feeder Break, Steam Generator Tube Rupture, and Shutdown State Accident. Analysis results for only the reference Small LOCA Accident scenario (which is a very low probability event) are discussed in this paper. (author)

  20. Start-up of a power unit of a thermal power plant auxiliary system with supply from a hydropower plant

    Directory of Open Access Journals (Sweden)

    Zbigniew Lubośny

    2013-09-01

    Full Text Available This article discusses the issues related to a power unit of a thermal power plant start-up with the use of a hydropower plant. Hydropower plant can supply and will enable start-up of auxiliary equipment in a power unit of a thermal power plant. Due to high capacity of auxiliary drives, startup of auxiliaries in a thermal power plant after blackout (and boiler shutdown is not possible from emergency energy sources in the power plant. In such a case an external electricity source with high capacity is required.

  1. A demonstration of the value of general purpose, on-board satellite computers

    Science.gov (United States)

    Jenkins, R. E.; Whisnant, J. M.

    1978-01-01

    Failure of the solar panels to erect and spin stabilize the TRANSIT Improvement Program (TIP) satellites is discussed, with emphasis on how the flight computer was reprogrammed to perform various control functions in order to achieve a partial mission success. These functions include: (1) power management to avoid troublesome spacecraft blackouts; (2) achieve enough spin stability to fire the OATS thruster; (3) raise the parking orbit to a workable altitude; (4) remove a high tumble rate which was the indirect result of the failure; and (5) deploy the gravity-gradient boom successfully on TIP-3.

  2. Electron depletion via cathode spot dispersion of dielectric powder into an overhead plasma

    International Nuclear Information System (INIS)

    The effectiveness of cathode spot delivered dielectric particles for the purpose of plasma depletion is investigated. Here, cathode spot flows kinetically entrain and accelerate dielectric particles originally at rest into a background plasma. The time variation of the background plasma density is tracked using a cylindrical Langmuir probe biased approximately at electron saturation. As inferred from changes in the electron saturation current, depletion fractions of up to 95% are observed. This method could be exploited as a means of communications blackout mitigation for manned and unmanned reentering spacecraft as well as any high speed vehicle enveloped by a dense plasma layer

  3. Wind Power Impact to Transient and Voltage Stability of the Power System in Eastern Denmark

    DEFF Research Database (Denmark)

    Rasmussen, Joana; Jørgensen, Preben; Palsson, Magni Thor;

    2005-01-01

    Voltage stability, transient stability and reactive power compensation are extremely important issues for largescale integration of wind power in areas distant from the main transmission system in Eastern Denmark. This paper describes the application of a dynamic wind farm model in simulation...... studies for assessments of a large wind power penetration. The simulation results reveal problems with voltage stability due to the characteristic of wind turbine generation as well as the inability of the power system to meet the reactive power demand. Furthermore, the established model is applied to...... analyse challenges in system protection as means to reduce the risk of widespread blackouts....

  4. New Orleans may go municipal

    International Nuclear Information System (INIS)

    Recent moves by the New Orleans City Council to consolidate two investor-owned utilities operating under franchise agreements into a publicly owned utility could make the 179,000-user utility the nation's 12th ranking public power system. Voters have changed their minds on the advantages of local control because of costly blackouts. At the root of the effort are economic concerns and some unpaid IOUs owed by the franchise companies because of nuclear plant construction. A task force recommended a municipal buyout

  5. Analysis of some antecipated transients without scram for PWR type reactors by coupling of the CORAN code to the ALMOD code system

    International Nuclear Information System (INIS)

    This study investigates some antecipated transients without scram for a pressurized water cooled reactor, using coupling of the containment CORAN code to the ALMOD code system, under severe random conditions. This coupling has the objective of including containment model as part of an unified code system. These severe conditions include failure of reactor scram, following a station black-out and emergency power initiation for the burn-up status at the beginning and end of the cycle. Furthermore, for the burn-up status at the end of the cycle, a failure in the closure of the pressurizer relief valve was also investigated. (Author)

  6. The relaxation of the operation restrictions at typhoon period for Taipower's nuclear power plant

    International Nuclear Information System (INIS)

    This paper analyzes the station blackout event for Taipower's nuclear power plant and proposes a plan whereby the availability of the plant at typhoon period can be increased through a systematic approach to improvements in the old operating restrictions. The conclusions have shown that the old operating restrictions were too strict and can be relaxed without increasing the likelihood of core damage or core melt for the accident sequence. After a detailed review of this analysis report, Republic of China Atomic Energy Commission (ROCAEC) has approved the relaxation of the operating restrictions as proposed by Taiwan Power Company. (author)

  7. Regulatory analysis for Generic Issue 23: Reactor coolant pump seal failure. Draft report for comment

    International Nuclear Information System (INIS)

    This report presents the regulatory/backfit analysis for Generic Issue 23 (GI-23), 'Reactor Coolant Pump Seal Failure'. A backfit analysis in accordance with 10 CFR 50.109 is presented in Appendix E. The proposed resolution includes quality assurance provisions for reactor coolant pump seals, instrumentation and procedures for monitoring seal performance, and provisions for seal cooling during off-normal plant conditions involving loss of all seal cooling such as station blackout. Research, technical data, and other analyses supporting the resolution of this issue are summarized in the technical findings report (NUREG/CR-4948) and cost/benefit report (NUREG/CR-5167). (author)

  8. Verification of voltage/frequency requirement for emergency diesel generator in nuclear power plant using dynamic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hur, Jin-Suk; Roh, Myung- Sub [KEPCO International Nuclear Graduate School, 1456-1 Shinam-ri, Seosaeng-myeon, Ulju-gun, Ulsan, 689-882 (Korea, Republic of)

    2014-02-12

    One major cause of the plant shutdown is the loss of electrical power. The study is to comprehend the coping action against station blackout including emergency diesel generator, sequential loading of safety system and to ensure that the emergency diesel generator should meet requirements, especially voltage and frequency criteria using modeling tool. This paper also considered the change of the sequencing time and load capacity only for finding electrical design margin. However, the revision of load list must be verified with safety analysis. From this study, it is discovered that new load calculation is a key factor in EDG localization and in-house capability increase.

  9. Profound hypoglycemia-ınduced by vaccinium corymbosum juice and laurocerasus fruit

    OpenAIRE

    Ahmet Hamdi Aktan; Abdullah Ozcelik; Erkan Cure; Medine Cumhur Cure; Suleyman Yuce

    2014-01-01

    An emergency intervention was performed in a 75-year-old male patient with hypoglycemic attack and blackout. Although he was diagnosed with prediabetes before 2 years, he did not take any anti-diabetic drug or follow dietary advice. He drank Vaccinium corymbosum L (VC) juice daily with a belief that it increases sexual potency. Before the development of hypoglycemia, the patient had consumed about 500 ml VC juice in addition to eating 200-300 gram of Laurocerasus officinalis (LO) fruit. The m...

  10. Fusion

    CERN Document Server

    Mahaffey, James A

    2012-01-01

    As energy problems of the world grow, work toward fusion power continues at a greater pace than ever before. The topic of fusion is one that is often met with the most recognition and interest in the nuclear power arena. Written in clear and jargon-free prose, Fusion explores the big bang of creation to the blackout death of worn-out stars. A brief history of fusion research, beginning with the first tentative theories in the early 20th century, is also discussed, as well as the race for fusion power. This brand-new, full-color resource examines the various programs currently being funded or p

  11. One year of Italian press review in the energy domain; Une annee de revue de presse italienne dans le domaine de l'energie

    Energy Technology Data Exchange (ETDEWEB)

    Augier, L.; Perna, N.; Carles, R.

    2004-03-01

    In terms of energy, 2003 has been an important and key year for Italy with a highlight: the black-out of September 28, 2003 which has paralyzed part of Italy. This event has led to think about the necessity for Italy to diversify its energy sources. This requires a reinforcement of energy efficiency, a rational use of energy, a policy of construction of new facilities, the use of biomass fuels and the promotion of renewable energy sources. This report groups together the overall brief news written by the scientific service of the French Embassy in Italy about this topic and spread to the readers of electronic bulletins. (J.S.)

  12. Simulation of a low-pressure severe accident scenario in a PWR with ATHLET-CD

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Mathias; Koch, Marco K. [Bochum Univ. (Germany). Reactor Simulation and Safety Group

    2013-07-01

    The plant behavior of a Pressurized Water Reactor (PWR) during a severe accident scenario is analyzed with system code ATHLET-CD Mod. 2.2C in order to assess the code capabilities in terms of the late-phase of the core degradation. For this purpose a severe accident sequence caused by a Station Black-out and a large break in the primary cooling system is simulated both without any accident management measures and with a delayed reflooding of the substantially degraded core. Selected code results are presented in this paper. (orig.)

  13. A study of core melting phenomena in reactor severe accident of PWR

    Energy Technology Data Exchange (ETDEWEB)

    Jeun, Gyoo Dong; Park, Shane; Kim, Jong Sun; Kim, Sung Joong [Hanyang Univ., Seoul (Korea, Republic of); Kim, Jin Man [Korea Maritime Univ., Busan (Korea, Republic of)

    2001-03-15

    In the 4th year, SCDAP/RELAP5 best estimate input data obtained from the TMI-2 accident analysis were applied to the analysis of domestic nuclear power plant. Ulchin nuclear power plant unit 3, 4 were selected as reference plant and steam generator tube rupture, station blackout SCDAP/RELAP5 calculation were performed to verify the adequacy of the best estimate input parameters and the adequacy of related models. Also, System 80+ EVSE simulation was executed to study steam explosion phenomena in the reactor cavity and EVSE load test was performed on the simplified reactor cavity geometry using TRACER-II code.

  14. Techniques for Improving Filters in Power Grid Contingency Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Adolf, Robert D.; Haglin, David J.; Halappanavar, Mahantesh; Chen, Yousu; Huang, Zhenyu

    2011-12-31

    In large-scale power transmission systems, predicting faults and preemptively taking corrective action to avoid them is essential to preventing rolling blackouts. The computational study of the constantly-shifting state of the power grid and its weaknesses is called contingency analysis. Multiple-contingency planning in the electrical grid is one example of a complex monitoring system where a full computational solution is operationally infeasible. We present a general framework for building and evaluating resource-aware models of filtering techniques for this type of monitoring.

  15. Severe accident sequence assessment for boiling water reactors: program overview

    International Nuclear Information System (INIS)

    The Severe Accident Sequence Assessment (SASA) Program was started at the Oak Ridge National Laboratory (ORNL) in June 1980. This report documents the initial planning, specification of objectives, potential uses of the results, plan of attack, and preliminary results. ORNL was assigned the Brown's Ferry Unit 1 Plant with the station blackout being the initial sequence set to be addressed. This set includes: (1) loss of offsite and onsite ac power with no coolant injection; and (2) loss of offsite and onsite ac power with high pressure coolant injection (HPCI) and reactor core isolation cooling (RCIC) as long as dc power supply lasts. This report includes representative preliminary results for the former case

  16. Review of Public Safety in Viewpoint of Complex Networks

    International Nuclear Information System (INIS)

    In this paper, a brief review of public safety in viewpoint of complex networks is presented. Public safety incidents are divided into four categories: natural disasters, industry accidents, public health and social security, in which the complex network approaches and theories are need. We review how the complex network methods was developed and used in the studies of the three kinds of public safety incidents. The typical public safety incidents studied by the complex network methods in this paper are introduced, including the natural disaster chains, blackouts on electric power grids and epidemic spreading. Finally, we look ahead to the application prospects of the complex network theory on public safety.

  17. Vehicle routing for the last mile of power system restoration

    Energy Technology Data Exchange (ETDEWEB)

    Bent, Russell W [Los Alamos National Laboratory; Coffrin, Carleton [Los Alamos National Laboratory; Van Hentenryck, Pascal [BROWN UNIV.

    2010-11-23

    This paper studied a novel problem in power system restoration: the Power Restoration Vehicle Routing Problem (PRVRP). The goal of PRVRPs is to decide how coordinate repair crews effectively in order to recover from blackouts as fast as possible after a disaster has occurred. PRVRPs are complex problems that combine vehicle routing and power restoration scheduling problems. The paper proposed a multi-stage optimization algorithm based on the idea of constraint injection that meets the aggressive runtime constraints necessary for disaster recovery. The algorithms were validated on benchmarks produced by the Los Alamos National Laboratory, using the infrastructure of the United States. The disaster scenarios were generated by state-of-the-art hurricane simulation tools similar to those used by the National Hurricane Center. Experimental results show that the constraint-injection algorithms can reduce the blackouts by 50% or more over field practices. Moreover, the results show that the constraint-injection algorithm using large neighborhood search over a blackbox simulator provide competitive quality and scales better than using a MIP solver on the subproblems.

  18. TRANSV2: a thermal-hydraulic analysis code for research reactors

    International Nuclear Information System (INIS)

    TRANSV2 is a thermal-hydraulic analysis code to be used in MTR-type research. It was developed to study the reactor in steady-state condition and to analyze loss of flow accidents (LOFA) produced by operational accidents such as blackout, pump failure and pump stick. Depending on the case to be analyzed, the user has the option to give the time dependent flow rate, the scram reactivity curve and the axial power distribution as input data. The hydraulic transient could be analyzed using an analytical solution, the pump characteristic curves or polynomials to approximate the characteristic curve of a typical single suction pump. The program has also a complete heat transfer correlations package to be applied to both downward flow and upward flow. Some particular cases of accidents could be also studied using this program, such as the case in which one pump failed without scram. This report presents a description of the program, including the input data description and the program listing. The last part of the report gives some results obtained for the up-graded JRR-3 reactor in the case of blackout as a benchmark problem. (author)

  19. Lights out: Impact of the August 2003 power outage on mortality in New York, NY

    Science.gov (United States)

    Anderson, G. Brooke; Bell, Michelle L.

    2012-01-01

    Background Little is known about how power outages affect health. We investigated mortality effects of the largest US blackout to date, August 14–15, 2003 in New York, NY. Methods We estimated mortality risk in New York, NY, using a generalized linear model with data from 1987–2005. We incorporated possible confounders, including weather and long-term and seasonal mortality trends. Results During the blackout, mortality increased for accidental deaths (122% [95% confidence interval = 28%–287%]) and non-accidental (i.e., disease-related) deaths (25% [12%–41%]), resulting in approximately 90 excess deaths. Increased mortality was not from deaths being advanced by a few days; rather, mortality risk remained slightly elevated through August 2003. Discussion To our knowledge, this is the first analysis of power outages and non-accidental mortality. Understanding the impact of power outages on human health is relevant, given that increased energy demand and climate change are likely to put added strain on power grids. PMID:22252408

  20. Modelling of Core Degradation and Progression of Severe Accident by Using MELCOR Code

    International Nuclear Information System (INIS)

    After Fukushima Daiichi Nuclear Accident, every single nuclear-field organization in the world focused in the analysis and study of scenarios that leads to core damage and hydrogen releases, in this way the integrated code MELCOR is used by the Mexican Regulatory Body as a tool in the analysis of severe accident progression, core melting and degradation. Scenarios related to core melting could provide information that show important parameters such as: time to reach the core damage, time window for level recovery, etc. This information is useful in the analysis of progression for this kind of events. In this work, Mexican Regulatory Body presents two simulations for different scenarios: a) Station Blackout with no cooling water injection and b) Station Blackout with late cooling water injection. Those two scenarios enclose the response of the fuel under Severe Accident conditions (progression of melting, relocation, temperature profile), plots in this document are qualitative items that allow to analyze the behavior for fuel/core elements. (author)

  1. POWER STABILITY MONITORING BASED ON VOLTAGE INSTABILITY PREDICTION APPROACH THROUGH WIDE AREA SYSTEM

    Directory of Open Access Journals (Sweden)

    H. H. Goh

    2014-01-01

    Full Text Available Nowadays, power systems are being forced to operate closer to its security limit due to current economic growth and the difficulties to upgrade the existing grid infrastructure. With the sudden increment of power demand, voltage instability problem has become a main concern to the power system operator because voltage instability has led or crucially contributed to some major blackouts throughout the world. Hence, methods for early warning and early prevention are required to prevent the power system from a collapse and led to blackout. Real-time voltage instability predictor method is applied on one of the load areas in Tenaga Nasional Berhad (TNB network in this study. Voltage instability predictor calculation is performed according to the real-time measurement provided by Phasor Measurement Units (PMUs. The voltage instability predictor calculates the power margin and makes comparison to the pre-set margin threshold. Last but not least, the stability condition of the system is based on the comparison between the margin and the pre-set threshold. The main perception is to ensure the margin index always stay positive and suitable early prevention should be implemented when the index is close to zero.

  2. Contingency Analysis of Cascading Line Outage Events

    Energy Technology Data Exchange (ETDEWEB)

    Thomas L Baldwin; Magdy S Tawfik; Miles McQueen

    2011-03-01

    As the US power systems continue to increase in size and complexity, including the growth of smart grids, larger blackouts due to cascading outages become more likely. Grid congestion is often associated with a cascading collapse leading to a major blackout. Such a collapse is characterized by a self-sustaining sequence of line outages followed by a topology breakup of the network. This paper addresses the implementation and testing of a process for N-k contingency analysis and sequential cascading outage simulation in order to identify potential cascading modes. A modeling approach described in this paper offers a unique capability to identify initiating events that may lead to cascading outages. It predicts the development of cascading events by identifying and visualizing potential cascading tiers. The proposed approach was implemented using a 328-bus simplified SERC power system network. The results of the study indicate that initiating events and possible cascading chains may be identified, ranked and visualized. This approach may be used to improve the reliability of a transmission grid and reduce its vulnerability to cascading outages.

  3. Risk energy transition. Ways out of the impasse

    International Nuclear Information System (INIS)

    The exit of the use of nuclear energy in Germany, it was decided in the summer of 2011 in a rush. Now it is becoming obvious that there is no realistic plan for the conversion of energy supply in the envisaged deadline of ten years. For the conversion of our entire power supply and therefore our economy the period is too short. It lacks a robust empirical reason that have to deal with the issues of security of supply, the affordability, the impact on economic development and social justice. Thus, this treansition threatens to fail at their contradictions. Konrad Kleinknecht tries in his book, to name the problems and to find answers. For him, arise the following questions: What are our opportunity to replace with wind and solar power to replace a part of the power supply? What power sources provide secured capacity? Can we dispense with coal-fired plants? Do we need new power lines? How power may be stored? How real is the risk of blackouts in windless nights? Will the power prices continue to rise? Can be avoided the major risks of the energy transition with a fundamental reform of the Renewable Energies Act (EEG)? The power supply must serve the common good and benefit the industrial site Germany. A blackout would be a disaster for the whole country, it must be avoided at all events. How can we manage this, the author present in his evocative book.

  4. 基于“站-线-变-户”电网模型的预约停电管理模型设计%Appointment power outage management business model design based on “Station - line - change - households” grid model

    Institute of Scientific and Technical Information of China (English)

    于涛

    2014-01-01

    Based oninformation integration camp with "Station - line - change - households" grid model, appointment blackout that allow customers to participate in the development of power cut scheme will be performed in the power supply enterprise customer information and interaction platform.Establish an appointment outage management model, namely screening appointment blackout customers,select the best service channels to communicate with customers,pooled analysis of customer feedback across channels,and develop optimal algorithm to formulate an optimal power cut scheme.%本文基于营配信息集成“站-线-变-户”电网模型,让客户参与停电计划的制定,在供电企业客服信息与互动平台实行预约停电。建立预约停电管理模型,即筛选预约停电客户群,选择最佳服务渠道与客户进行沟通,汇集分析各渠道客户的意见,通过算法处理制定最优的停电计划。

  5. Study of risk reduction by improving operation of reactor core isolation cooling system

    International Nuclear Information System (INIS)

    The Fukushima Daiichi nuclear power plant fell into a station blackout (SBO) due to the earthquake and tsunami in which most of the core cooling systems were disabled. In the units 2 and 3, water injection to the core was performed only by water injection system with turbine driven pumps. In particular, it is inferred from observed plant parameters that the reactor core isolation cooling system (RCIC) continued its operation much longer than it was originally expected (8 hours). Since the preparation of safety measures did not work, the reactor core damaged. With a view to reduce risk of station blackout events in a BWR by accident management, this study investigated the efficacy of operation procedures that takes advantage of RCIC which can be operated with only equipment inside reactor building and does not require an AC power source. The efficacy was assessed in this study by two steps. The first step is a thermal hydraulic analysis with the RETRAN3D code to estimate the potential extension of duration of core cooling by RCIC and the second step is the estimation of time required for recovery of off-site power from experiences at nuclear power stations under the 3.11 earthquake. This study showed that it is possible to implement more reliable measures for accident termination and to greatly reduce the risk of SBO by the installation of accident management measures with use of RCIC for extension of core cooling under SBO conditions. (author)

  6. The state of the market

    International Nuclear Information System (INIS)

    This paper proposed that the 4.3 cent retail price cap on electricity in Ontario be reformed to ensure an adequate supply at stable and predictable prices without cross-subsidization from the taxpayer. It was argued that the price cap has not helped conservation efforts. Every customer needs protection from price spikes and the mechanism of the 'Load Serving Entity' is postulated as being able to contract for supply for customers. Turning to infrastructure upgrading, price signals alone will not drive investment. Auctions for generation and demand response would provide participants with the assurances and incentives needed for investment. The major power blackout that occurred in August 2003 in the northeastern United States and Canada was also discussed. It was cautioned that generation and demand must be well-balanced with purchases made based on necessity, and operation must be done with unplanned contingencies in mind so that problems do not cascade into neighbouring jurisdictions. An in-depth analysis of the events leading up to the blackout was also presented. The author was not confident that at the date of his speech all necessary remedial steps had been taken to prevent a similar occurrence. 20 figs

  7. Control area readiness audit report of the Independent Electricity Market Operator (IMO)

    International Nuclear Information System (INIS)

    The Independent Electricity Market Operator (IMO) is a control area authority that is responsible for the safe and reliable operation of its portion of the bulk electric system in cooperation with neighbouring control areas. This audit by the North American Electric Reliability Council (NERC) reviewed the readiness of Ontario's IMO to meets its responsibilities as a control area operator. NERC recommended specific actions to correct the deficiencies that resulted in the blackout in southeastern Ontario and northeastern United States on August 14, 2003. Initiatives to strengthen compliance with existing standards were also suggested along with longer-term technical initiatives to prevent or mitigate the impacts of cascading blackouts in the future. The audit process included: a self-assessment questionnaire to the control area being audited; a questionnaire to neighbouring control areas; a questionnaire to the reliability coordinator and an on-site audit by a selected audit team. The following issues were reviewed: criteria and compliance, authority, responsibilities in the planning time frame, real time monitoring, system restoration, delegation of reliability coordinator functions, outage coordination, transmission and generation relaying, energy emergency plan, operating policy, line clearances, and nuclear power plant requirements. It was concluded that the IMO has the necessary plans, procedures, processes, tools and trained personnel to respond to emergency events. The audit did not find any major operational problems, but offered a few recommendations for improvement. tabs

  8. An analysis on the severe accident progression with operator recovery actions

    International Nuclear Information System (INIS)

    Highlights: • Severe accident progression for the station blackout and SBLOCA accident. • Analyses on APR1400 using MELCOR. • Operator recovery actions for decay heat removal and inventory make up. • Determine the time allowed for the operator to prevent reactor vessel failure. • Insight for the operator recovery actions for the severe accident management. - Abstract: Analyses on the severe accident progressions for the station blackout (SBO) accident and small break LOCA (SBLOCA) initiated severe accident were performed for APR1400 by using MELCOR computer code. Operator recovery actions for decay heat removal and inventory make up using a depressurization system and safety injection pump were simulated in parallel with a simulation of the severe accident progression. Sensitivity studies on the operator actions were performed to investigate the changes in the timing of the reactor vessel failure and to determine the time allowed for the operator to prevent reactor vessel failure. Sensitivity analyses on the effect of major modeling parameters were performed additionally to quantify the uncertainties in timing. It is found that the operator has about 2 h for the recovery actions after the indication of core damage by the signal of core exit thermocouple (CET) for the SBLOCA initiated severe accident, while the operator has to take immediate actions after the indication of core damage by CET for the SBO accident

  9. Application of SMES Unit in Black Start

    Science.gov (United States)

    Yang, Jun; Liu, Wenqing; Liu, Pei

    Blackout of large area is a serious threat to modern power system, so power system restoration which is called Black Start is a critical task for reducing economic losses and social unrest caused by blackout. Traditiona black start sometimes may suffer from inflexible black start units and overvoltage and serious oscillation. As a power storage unit, SMES has the ability of fast exchanging active and reactive power with power grid in all four quadrants, so it is proposed as a new solution to improve the black start process in this paper. Comparing to traditional black start, some unique advantages of SMES for black start are presented. Also SMES model and related control strategy are introduced in detail. A simulation model is established based on PSCAD/EMTDC to investigate the validity and flexibility of SMES in black start. Simulation results show that SMES unit can bring thermal generators online, and it has better performance on overvoltage restraint and amping oscillation than traditional black start. Also, the performance of nonlinear PID-controlled SMES is better than that of PID-controlled SMES.

  10. Investigation on accident management measures for VVER-1000 reactors

    International Nuclear Information System (INIS)

    A consequence of a total loss of AC power supply (station blackout) leading to unavailability of major active safety systems which could not perform their safety functions is that the safety criteria ensuring a secure operation of the nuclear power plant would be violated and a consequent core heat-up with possible core degradation would occur. Currently, a study which examines the thermal-hydraulic behaviour of the plant during the early phase of the scenario is being performed. This paper focuses on the possibilities for delay or mitigation of the accident sequence to progress into a severe one by applying Accident Management Measures (AMM). The strategy 'Primary circuit depressurization' as a basic strategy, which is realized in the management of severe accidents is being investigated. By reducing the load over the vessel under severe accident conditions, prerequisites for maintaining the integrity of the primary circuit are being created. The time-margins for operators' intervention as key issues are being also assessed. The task is accomplished by applying the GRS thermal-hydraulic system code ATHLET. In addition, a comparative analysis of the accident progression for a station blackout event for both a reference German PWR and a reference VVER-1000, taking into account the plant specifics, is being performed. (authors)

  11. The - compromised? - future of natural gas

    International Nuclear Information System (INIS)

    Will natural gas be the main loser of the January 2009 crisis between Ukraine and Russia? The demonstration is made that the European Union is not free from the risk of a severe supply disruption. This is a bad news considering that the power generation is the growth vector of natural gas. Even if the gas black-out cannot exist, the power black-out still can happen. As soon as the Russian-Ukrainian conflict has occurred, the other energy sources (nuclear and renewable) have been called for help in Europe while coal is in the expectation. Since some time now, gas has to face several trend changes. First, uncertainty is increasing considering its growth prospects. The new version of the gas pluri-annual indicative plan (PIP Gaz) would foresee a stagnation of gas consumption up to 2020 (consequence of the French environmental policy), while the previous plan had foreseen a 2.1% annual growth rate between 2005 and 2015. Second, the direct indexing of gas prices on oil prices can have undesirable effects. Finally, the u-turn of the USA with respect to liquefied natural gas (LNG) may penalize its development. What answers should the European Union give in front of these uncertainties? Have the companies modified their strategy? Is the future of gas still fine? These are the questions debated during a round table organized by the BIP, the French Bulletin of Petroleum Industry. (J.S.)

  12. Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Analia Bonelli

    2012-01-01

    Full Text Available A description of the results for a Station Black-Out analysis for Atucha 2 Nuclear Power Plant is presented here. Calculations were performed with MELCOR 1.8.6 YV3165 Code. Atucha 2 is a pressurized heavy water reactor, cooled and moderated with heavy water, by two separate systems, presently under final construction in Argentina. The initiating event is loss of power, accompanied by the failure of four out of four diesel generators. All remaining plant safety systems are supposed to be available. It is assumed that during the Station Black-Out sequence the first pressurizer safety valve fails stuck open after 3 cycles of water release, respectively, 17 cycles in total. During the transient, the water in the fuel channels evaporates first while the moderator tank is still partially full. The moderator tank inventory acts as a temporary heat sink for the decay heat, which is evacuated through conduction and radiation heat transfer, delaying core degradation. This feature, together with the large volume of the steel filler pieces in the lower plenum and a high primary system volume to thermal power ratio, derives in a very slow transient in which RPV failure time is four to five times larger than that of other German PWRs.

  13. Important objectives for the performance of an individual plant evaluation

    International Nuclear Information System (INIS)

    The Pennsylvania Power ampersand Light Company (PP ampersand L) operates the Susquehanna Steam Electric Station, a two-unit 1050-MW(electric) boiling water reactor (BWR) 4, Mark II plant. Unit 1 has been in operation since 1982 and Unit 2 since 1984. The PP ampersand L views on probabilistic risk assessment (PRA) have been shaped by early in-house experience during the period 1981 to 1985 in deterministic studies of station black-out and anticipated transient without scram (ATWS) and a conventional level 3 PRA for Susquehanna performed by a contractor. In the performance of studies of station black-out and ATWS, the objective was to assure that procedures would utilize all of the plant's capabilities to avoid or minimize damage regardless of the extent of additional equipment failures accompanying or resulting from these initiators. It was found that when the emergency operating procedures (EOPs) were properly structured to accommodate the potential for additional equipment failures, damage to the plant could be avoided or greatly reduced in severity below what could be expected in the absence of optimized procedures (even for very severely degraded conditions of the plant). Accomplishment of such an improvement required that the modifications be incorporated into the EOPs explicitly and that operators be trained in their use. In the formulation of the Susquehanna EOPs and the associated program of operator training, it was attempted to assure that the optimized procedures and associated training would be in place and effective

  14. Application of computational intelligence techniques for load shedding in power systems: A review

    International Nuclear Information System (INIS)

    Highlights: • The power system blackout history of last two decades is presented. • Conventional load shedding techniques, their types and limitations are presented. • Applications of intelligent techniques in load shedding are presented. • Intelligent techniques include ANN, fuzzy logic, ANFIS, genetic algorithm and PSO. • The discussion and comparison between these techniques are provided. - Abstract: Recent blackouts around the world question the reliability of conventional and adaptive load shedding techniques in avoiding such power outages. To address this issue, reliable techniques are required to provide fast and accurate load shedding to prevent collapse in the power system. Computational intelligence techniques, due to their robustness and flexibility in dealing with complex non-linear systems, could be an option in addressing this problem. Computational intelligence includes techniques like artificial neural networks, genetic algorithms, fuzzy logic control, adaptive neuro-fuzzy inference system, and particle swarm optimization. Research in these techniques is being undertaken in order to discover means for more efficient and reliable load shedding. This paper provides an overview of these techniques as applied to load shedding in a power system. This paper also compares the advantages of computational intelligence techniques over conventional load shedding techniques. Finally, this paper discusses the limitation of computational intelligence techniques, which restricts their usage in load shedding in real time

  15. A study on the characteristics, predictions and policies of China’s eight main power grids

    International Nuclear Information System (INIS)

    Highlights: • Indian blackout is analyzed as a warning for China’s power system. • Issues and recommendations of China’s eight power grids are presented. • Five models are employed for scenario analysis on power generation and consumption. • The optimized combined model outperforms other models. • Methods towards balancing power generation and environmental impacts are proposed. - Abstract: Electricity is an indispensable energy source for modern social and economic development. However, large-scale blackouts can cause incalculable loss to society. In 2012, three major Indian power grids collapsed, resulting in the interruption of the electricity supply to over 600 million people. To avoid an event like that, China needs to forecast the power generation and consumption of eight power grids effectively. This paper first analyzes the characteristics of eight power grids and then proposes a combined model based on three improved grey models optimized by a differential evolution algorithm to predict electricity production and consumption of each power grid. The optimized combined forecasting model provides a better prediction than other models, and it is also the most workable and satisfactory model. Experiment results show electricity production and consumption would increase. In consideration of the real situation and existing problems, some suggestions are proposed. The government could decrease thermal power and exploit renewable energy power, like hydroelectric power, wind power and solar power, to ensure the safe and reliable operation of China’s major power grids and protect environment

  16. Anticipating Interruptions. Security and risk in a liberalized electricity infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Silvast, A.

    2013-11-01

    During the past ten years, a number of social scientists have emphasized the importance of material infrastructures like electricity supply as a research topic for the social sciences. The developing of such new perspectives concerning infrastructures also includes uncertainties and risks. This research analyzes the management of uncertainties in the Finnish electricity infrastructure by posing the following research question: how are electricity interruptions, or blackouts, anticipated in Finland and how are these interruptions managed as risks? The main research methodology of the work is multi-sited field work. The empirical materials include interviews with experts and lay people (33 interviews); participant observation in two electricity control rooms; an electricity consumer survey (115 respondents); and also a number of infrastructure and security policy documents and observations from electricity security seminars. The materials were primarily gathered between 2004 and 2008. Social science research often links risks with major current social changes or socio-cultural risk perceptions. In recent international social science discussions, however, a new research topic has emerged - those styles of reasoning and techniques of governance that are deployed to manage risk as a practical matter. My study explores these themes empirically by focusing on the specific habitual practices of risk management in the Finnish electricity infrastructure. The work develops various also semi-ethnographic inquiries into infrastructure risk techniques like monitor screening of real-time risks in electricity control rooms; the management of risks in a liberalized electricity market; the emergence of Finnish reasoning about blackouts from a specific historical background; and the ways in which electricity consumers respond to blackouts in their homes. In addition, the work reflects upon the position of a risk researcher in those situations when the research subjects do not define

  17. Handling of design and licensing changes in India

    International Nuclear Information System (INIS)

    In preparing the PSR for LTO authorization, all the agreed upon design changes and lessons learned from the Fukushima Daiichi accident were taken into consideration and particular emphasis was put on ageing and plant life management related findings. Major findings from the owners and utilities assessment of existing NPPs in India were that they: — Meet regulatory requirements for external events; — Have sufficient provisions to ensure core cooling in absence of off-site and on-site power supplies; — Have sufficient on-site water storage for decay heat removal; — Implement procedures to handle external events, loss of ultimate heat sink and station blackout. Gaps were identified for review and design change. The following list includes ways to address these gaps: — Incorporate an automatic reactor trip in all NPPs for seismic events; —Strengthen the provisions for beyond design basis accidents; — Increase on-site water supplies; — Procure and install additional diesel generator sets for charging batteries and running small capacity pumps; — Incorporate provisions for containment safety and fuel pool safety; — Formalize and implement severe accident management guidelines. The magnitude of postulated design basis natural events and the related requirements for siting and design of NPPs, as specified in AERB safety regulations, are appropriate and sufficiently conservative. However, in the light of the Fukushima Daiichi accident, it is prudent to further enhance this conservatism and also to postulate beyond design basis natural events. Additional measures incorporated following the Fukushima Daiichi accident include: — Tie-in points outside the reactor building to connect to an external water supply to inject water into the core from outside the reactor building; — Guidelines made available to all NPPs on the use, quantification and incorporation of safety margins with respect to earthquakes and external flooding; — Early tsunami warning

  18. [Association between risky drinking behaviors and risk groups of substance abuse: a study in Japanese college freshmen].

    Science.gov (United States)

    Shimane, Takuya; Wada, Kiyoshi; Mishima, Kenichi; Fujiwara, Michihiro

    2009-12-01

    This study examines the prevalence of risky drinking and the association between risky drinking behaviors and risk groups of substance abuse among college freshmen. A total of 376 college freshmen (126 boys and 248 girls) in a Japanese university participated in the study. The subjects were asked to complete self-administered, anonymous questionnaires during their class. The number of participants who had used drugs was small. The following 2 items for substance abuse were included in the questionnaires: (1) those who had drug using peers who used drugs and (2) those who had been persuaded to use drugs by their peers. On the basis of the responses, the participants were classified into 3 groups: (1) high-risk group (HRG), which accounted for 1.4% of the subjects and comprised those who answered "yes" to both the above-mentioned two items; (2) risk group (RG), which accounted for 7.4% and comprised participants who answered "yes" to one of the two items; and (3) control group (CG), which accounted for 91.2% and comprised those who did not answer "yes" to either of the two items. Bivariate analyses were performed to evaluate the association between risky drinking behaviors and risk groups of substance abuse. The results of our study indicated that 87.0% of the participants reported lifetime alcohol use, and 69.4% reported the consumption of alcohol during the past 30 days. Of the former group, 21.4% had engaged in binge drinking, 8.6% had experienced alcohol-related harassment, 9.5% had experienced alcohol-induced blackouts, and 82.0% had experienced drinking alcohol with peers without adults. There were significant associations between risk groups of substance abuse and risky drinking such as binge drinking (p = 0.001), alcohol-induced blackouts (p = 0.020), alcohol-related harassment (p = 0.012), alcohol consumption during the past 30 days (p = 0.047). However, lifetime alcohol use (p = 0.264) and experience of drinking alcohol with peers without adults (p = 0

  19. Heat wave generates questions about Ontario's generation capacity

    International Nuclear Information System (INIS)

    Concerns regarding Ontario's power generation capacity were raised following a major blackout which occurred in August 2003. Power demand reached 26,170 MW during the weeks leading to the blackout, forcing the Independent Electricity System Operator (IESO) to ask residents to reduce electricity use during the day. The grid operator had also issued a forecast that Toronto could face rolling blackouts during times of heavy power demand. Ontario power consumption records were set in June and July of 2003 due to a heat wave, with hourly demand exceeding 25,000 MW on 53 occasions. Ontario was forced to import up to 3,400 MW (13 per cent of its power needs) from neighbouring provinces and the United States. During that period, the price of power had risen sharply to over 30 cents a kilowatt hour, although household consumers were still charged in the 5 to 10 cent range per kilowatt hour. However, it was noted that taxpayers will eventually bear the cost of importing power. The IESO noted that importing electricity is cheaper than the generation available in Ontario and that it is more economical to import, based on the market clearing price of all generators. In 2004, the IESO purchased 6 per cent of their electricity from the United States. That figure is expected to increase for 2005. Ontario generators produced 26.9 million MWh more in the summer of 2005 than during the same period in 2004 to meet electricity demand levels. It was noted that although importing power presently meets peak demand, the IESO agrees there is a need for new generation within Ontario. In addition to restarting Ontario's Pickering and Bruce nuclear facilities, more than 3,300 MW of new gas-fired generation is under construction or approved, and more than 9,000 MW are in various stages of approval. This paper discussed the effect of high energy costs on industry and Ontario's ability to meet future electricity demand in comparison to neighbouring jurisdictions. Issues regarding grid maintenance

  20. Schemes for protecting electric power systems; Esquemas de protecao de sistemas de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Paulo Cesar de

    2002-07-01

    The objective of this dissertation is to accomplish an introduction to the studies and the applications of the System Protection Schemes (SPS) used to maintain the electric power systems safety. A small group of definitions and concepts from the 'protection, reliability and power systems performance analysis' areas is presented with the objective of distinguishing SPS from the conventional system component protections. It also helps in understanding the functions of the SPS with more clarity. The SPS are used to maintain the integrity of the system when it is submitted to phenomena that provoke instability or cascade circuit outages. The classification and the description of these phenomena, as well as the SPS application are shown in this dissertation. The general structure of the SPS, the ways of classifying them and the different actions used by SPS to control the disturbances are the objectives of the analysis of this work. In order to exemplify, a vision is given of how the SPS are located in the Brazilian interconnected system (BIS) and also in the rest of the world. Some SPS used in Brazil deserved special attention. The analyses of the main blackouts that occurred in Brazil and in North America are presented, in a summarized term, in appendix I. Considerable knowledge is obtained from these analyses, leading to implementation measures that minimize the risk of interruptions in the energy supply. A comparison is also made of the degree of severity of the great blackouts that happened in Brazil and, for the two largest, an estimate of their respective interruption costs is made. In appendix II, an attempt was also made to establish the basic requirements for the SPS implementation using micro processing technology. Based on the experience lived during the studies developed by the group that analyzed the safety of the Bis after the blackout on March 11/1999, criteria and procedures to analyze the safety of the system and to accomplish studies of SPS

  1. A MARS and MIDAS Linked Accident Simulation for Large LOCA in APR1400

    International Nuclear Information System (INIS)

    A linked calculation utilizing the design-basis code MARS and the severe accident code MIDAS has been accomplished for a station blackout simulation in APR1400. The MARS code was developed by using the RELAP3/MOD3 and COBRA-TF codes, while the MIDAS code is currently under a development process using the MELCOR code. The objectives of this paper are to explain how to identify the MAR-MIDAS linked calculation outlines and the technical problems, including the MARS data transfer method, the MIDAS input generation works and so on. For the performance verification of the MARS-MIDAS linked calculation, the MARS, MIDAS and their linkage system are run independently for the same initiating event, so that their data can be compared with each other after the selection of proper variables

  2. A MARS and MIDAS Linked Accident Simulation for Large LOCA in APR1400

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young; Kim, K. R.; Kim, D. H.; Chung, B. D. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    A linked calculation utilizing the design-basis code MARS and the severe accident code MIDAS has been accomplished for a station blackout simulation in APR1400. The MARS code was developed by using the RELAP3/MOD3 and COBRA-TF codes, while the MIDAS code is currently under a development process using the MELCOR code. The objectives of this paper are to explain how to identify the MAR-MIDAS linked calculation outlines and the technical problems, including the MARS data transfer method, the MIDAS input generation works and so on. For the performance verification of the MARS-MIDAS linked calculation, the MARS, MIDAS and their linkage system are run independently for the same initiating event, so that their data can be compared with each other after the selection of proper variables.

  3. Schemes of a MARS and MIDAS linked simulation for SBO in APR1400

    International Nuclear Information System (INIS)

    A linked calculation utilizing the design-basis code MARS and the severe accident code MIDAS has been accomplished for a station blackout simulation in APR1400. The MARS code was developed by using the RELAP3/MOD3 and COBRA-TF codes, while the MIDAS code is currently under a development process using the MELCOR code. In this paper, the MAR-MIDAS linked calculation outlines and the technical problems are presented, including the MARS data transfer method, the MARS and MIDAS node mapping and variable definition principles, the MIDAS input generation works and so on. For the performance verification of the MARS-MIDAS linked calculation, the MARS, MIDAS and their linkage system are run independently for the same initiating event, so that their data can be compared with each other after the selection of proper variables. (author)

  4. The integrated resource planning of the energy sector as a basis to water management in urban areas

    Directory of Open Access Journals (Sweden)

    Gilberto de Martino Jannuzzi

    2008-12-01

    Full Text Available The Water Resources Planning in use doesn´t diverges substantially from the Traditional Energy Planning. With the energy crisis occurred at Brazil in 2001 the blackout possibility shows that the impact on the society might happen at any time. The same occurs to the water because of its scarcity. The Integrated Resource Planning (IRP was diffused as a way of fully managing a resource by the supply and demand sizes and can be considerated a viable option for the conventional planning. This composition is meant to do a study of the specific bibliography about the energy IRP and the Water Resource Management. Utilizing conceptions of the energy area, Water Integrated Resource Planning has been created to be used at the public utilities. The Water Integrated Resource Planning conducts the Water Integrated Management through this resource saving, joining this to a different tax and increasing the supply with alternative options such as the wastewater and the rainwater use.

  5. A genome-wide association study of autism incorporating autism diagnostic interview-revised, autism diagnostic observation schedule, and social responsiveness scale.

    Science.gov (United States)

    Connolly, John J; Glessner, Joseph T; Hakonarson, Hakon

    2013-01-01

    Efforts to understand the causes of autism spectrum disorders (ASDs) have been hampered by genetic complexity and heterogeneity among individuals. One strategy for reducing complexity is to target endophenotypes, simpler biologically based measures that may involve fewer genes and constitute a more homogenous sample. A genome-wide association study of 2,165 participants (mean age = 8.95 years) examined associations between genomic loci and individual assessment items from the Autism Diagnostic Interview-Revised, Autism Diagnostic Observation Schedule, and Social Responsiveness Scale. Significant associations with a number of loci were identified, including KCND2 (overly serious facial expressions), NOS2A (loss of motor skills), and NELL1 (faints, fits, or blackouts). These findings may help prioritize directions for future genomic efforts. PMID:22935194

  6. Small scale BWR core debris eutectics formation and melting experiment

    International Nuclear Information System (INIS)

    A small scale experiment has recently been performed at Oak Ridge under the auspices of the BWR Severe Accident Technology (BWRSAT) program to provide information concerning the formation of mixtures during heatup of representative BWR reactor vessel bottom head debris and to determine the composition and melting temperatures of these mixtures. The initial structure of the bottom head debris layers modeled in the experiment was taken from the results of recent BWR Accident Response (BWRSAR) code predictions for the short-term station blackout accident sequence. The experimental results provide useful information concerning the mixtures formed and their proportions and properties. The observed run-off of a stainless steel-zirconium eutectic alloy supports the contention that the initial pour from a BWR reactor vessel would consists of molten metals at relatively low temperatures. (orig.)

  7. Ising model for distribution networks

    CERN Document Server

    Hooyberghs, H; Giuraniuc, C; Van Schaeybroeck, B; Indekeu, J O

    2012-01-01

    An elementary Ising spin model is proposed for demonstrating cascading failures (break-downs, blackouts, collapses, avalanches, ...) that can occur in realistic networks for distribution and delivery by suppliers to consumers. A ferromagnetic Hamiltonian with quenched random fields results from policies that maximize the gap between demand and delivery. Such policies can arise in a competitive market where firms artificially create new demand, or in a solidary environment where too high a demand cannot reasonably be met. Network failure in the context of a policy of solidarity is possible when an initially active state becomes metastable and decays to a stable inactive state. We explore the characteristics of the demand and delivery, as well as the topological properties, which make the distribution network susceptible of failure. An effective temperature is defined, which governs the strength of the activity fluctuations which can induce a collapse. Numerical results, obtained by Monte Carlo simulations of t...

  8. Our energies have a future. A future without CO{sub 2}. Areva in 2005; Nos energies ont de l'avenir. Un avenir sans CO{sub 2}. Areva en 2005

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This document is the sustainable development and 2005 annual report altogether of Areva group. It presents first the challenges of energy for economical development, the climate change threat and the sustainability of nuclear power in particular with respect to radioactive wastes management and power blackouts. Then follows a presentation of Areva's 10 commitments for sustainable development (governance and continuous improvement, financial performance, innovation, customer satisfaction, commitment to employees, risk management and prevention, environmental protection, dialogue and consensus building, community involvement). The annual report presents: the 2005 highlights, Areva around the world, key data, corporate governance, organisation of the group, share information and shareholder relations, business review (front end division, reactors and services division, back end division, transmission and distribution division), financial report and glossary. (J.S.)

  9. Selectivity of power system protections at power swings in power system

    Directory of Open Access Journals (Sweden)

    Jan Machowski

    2012-12-01

    Full Text Available The paper discusses out-of-step protection systems such as: generator pole slip protections, out of step tripping protections, distance protections of step-up transformer, distance protections of transmission lines and transformers, power swing blocking, and special out-of-step protection. It is shown that all these protections make up a protection system, to which a setting concept uniform for the entire power system has to be applied. If a power system is inappropriately equipped with these protections, or their settings are inappropriate, they may operate unselectively, thus contributing to the development of power system blackouts. In the paper the concepts for a real power system are given for the two stages: target stage fully compliant with selectivity criteria, and transitional stage between the current and target stages.

  10. Culture in the Courtroom: Ethnocentrism and Juror Decision-Making

    Science.gov (United States)

    Maeder, Evelyn M.; Yamamoto, Susan

    2015-01-01

    The purpose of this study was to investigate whether a culturally-based argument in a non-insane automatism defense would be detrimental or beneficial to the defendant. We also examined how juror ethnocentrism might affect perceptions of such a defense. Participants read a fictional filicide homicide case in which the defendant claimed to have blacked out during the crime; we manipulated whether culture was used as an explanation for what precipitated the defendant’s blackout. We conducted path analyses to assess the role of ethnocentrism in predicting lower defendant credibility, and harsher verdict decisions. Results revealed an interaction between ethnocentrism and defense type, such that ethnocentrism related to lower perceived defendant credibility in the cultural condition, but not in the standard automatism condition. This study marks a starting point for empirically investigating the role of culture in the courtroom, which may aid scholars in discussing the merits of a standalone cultural defense. PMID:26353122

  11. Saving electricity in a hurry - update 2011

    Energy Technology Data Exchange (ETDEWEB)

    Pasquier, Sara Bryan

    2011-06-15

    As demonstrated by the March 2011 earthquake and tsunami-triggered blackouts in Japan, electricity shortfalls can happen anytime and anywhere. Countries can minimise the negative economic, social and environmental impacts of such electricity shortfalls by developing emergency energy-saving strategies before a crisis occurs. This new IEA report highlights preliminary findings and conclusions from electricity shortfalls in Japan, the United States, New Zealand, South Africa and Chile. It draws on recent analysis to: reinforce well-established guidelines on diagnosing electricity shortfalls, identifying energy-saving opportunities and selecting a package of energy-saving measures; and highlight proven practice for implementing emergency energy-saving programmes. This paper will be valuable to government, academic, private-sector and civil-society stakeholders who inform, develop and implement electricity policy in general, and emergency energy-saving programmes in particular.

  12. Analysis of Electromagnetic Wave Propagation in a Magnetized Re-Entry Plasma Sheath Via the Kinetic Equation

    Science.gov (United States)

    Manning, Robert M.

    2009-01-01

    Based on a theoretical model of the propagation of electromagnetic waves through a hypersonically induced plasma, it has been demonstrated that the classical radiofrequency communications blackout that is experienced during atmospheric reentry can be mitigated through the appropriate control of an external magnetic field of nominal magnitude. The model is based on the kinetic equation treatment of Vlasov and involves an analytical solution for the electric and magnetic fields within the plasma allowing for a description of the attendant transmission, reflection and absorption coefficients. The ability to transmit through the magnetized plasma is due to the magnetic windows that are created within the plasma via the well-known whistler modes of propagation. The case of 2 GHz transmission through a re-entry plasma is considered. The coefficients are found to be highly sensitive to the prevailing electron density and will thus require a dynamic control mechanism to vary the magnetic field as the plasma evolves through the re-entry phase.

  13. Study on MELCOR Modeling for Emergency External Water Injection Scenario of SBO in APR1400

    International Nuclear Information System (INIS)

    In the present study, a MELCOR model for APR1400 was developed and applied to analyze a SBO scenario selected to confirm the effectiveness of the means. In this analysis, the primary and secondary emergency cooling water injection were considered. Leakage from the Reactor Coolant Pump (RCP) seal and opening of the Atmosphere Dump Valve (ADV) were modeled as well to simulate the external pump injection strategy. In this study, the analysis results showed that the external injection strategy with an ADV manual opening could successfully cool down the reactor for a station blackout accident through its effective implementation. It was found that the RCP seal leakage rate is a sensitive parameter for depressurization of the RCS. In this regard, further study is needed to develop a realistic RCP seal leakage model, referring to detailed technical data

  14. A Dynamic Programming based method for optimizing power system restoration with high wind power penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Li, Pengfei;

    2016-01-01

    to its stable limits. Once the blackout happens, a well-designed restoration strategy is significant. This paper focuses on how to ameliorate the power system restoration procedures to adapt the high wind power penetration and how to take full advantages of the wind power plants during the...... and relatively low cost. Thus, many countries are increasing the wind power penetration in their power system step by step, such as Denmark, Spain and Germany. The incremental wind power penetration brings a lot of new issues in operation and programming. The power system sometimes will operate close...... restoration. In this paper, the possibility to exploit the stochastic wind power during restoration was discussed, and a Dynamic Programming (DP) method was proposed to make wind power contribute in the restoration rationally as far as possible. In this paper, the method is tested and verified by a modified...

  15. Updated Peach Bottom Model for MELCOR 1.8.6: Description and Comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Robb, Kevin R [ORNL

    2014-09-01

    A MELCOR 1.8.5 model of the Peach Bottom Unit 2 or 3 has been updated for MELCOR 1.8.6. Primarily, this update involved modification of the lower head modeling. Three additional updates were also performed. First, a finer nodalization of the containment wet well was employed. Second, the pressure differential used by the logic controlling the safety relief valve actuation was modified. Finally, an additional stochastic failure mechanism for the safety relief valves was added. Simulation results from models with and without the modifications were compared. All the analysis was performed by comparing key figures of merit from simulations of a long-term station blackout scenario. This report describes the model changes and the results of the comparisons.

  16. Choice experiment study on the willingness to pay to improve electricity services

    International Nuclear Information System (INIS)

    Modern forms of energy are an important vehicle towards poverty alleviation in rural areas of developing countries. Most developing countries' households rely heavily on wood fuel which impacts on their health and socio-economic status. To ease such a dependency, other modern forms of energy, namely electricity, need to be provided. However, the quality of the electricity service, namely reliability, is an important factor in reducing this dependency. This paper discusses a choice experiment valuation study conducted among electrified rural households located in Kisumu, Kenya, in which the willingness to pay (WTP) to avoid power outages or blackouts was estimated. A mixed logit estimation was applied to identify the various socio-economic and demographic characteristics which determine preferences in reducing power outages among a household's users. In conclusion, several of the socio-economic and demographic characteristics outlined in this paper were identified and can assist service differentiation to accommodate the diverse households' preferences towards the improvement of the electricity service.

  17. Dynamic Modeling of the Electric Transportation Network

    CERN Document Server

    Scir`e, A; Eguiluz, V M; Scir\\`{e}, Alessandro; Tuval, Id\\'an

    2005-01-01

    We introduce a model for the dynamic self-organization of the electric grid. The model is characterized by a conserved magnitude, energy, that can travel following the links of the network to satisfy nodes' load. The load fluctuates in time causing local overloads that drive the dynamic evolution of the network topology. Our model displays a transition from a fully connected network to a configuration with a non-trivial topology and where global failures are suppressed. The most efficient topology is characterized by an exponential degree distribution, in agreement with the topology of the real electric grid. The model intrinsically presents self-induced break-down events, which can be thought as representative of real black-outs.

  18. Fukushima accident study using MELCOR

    Institute of Scientific and Technical Information of China (English)

    Randall O Gauntt

    2013-01-01

    The accidents at the Fukushima Daiichi nuclear power station stunned the world as the sequences played out over severals days and videos of hydrogen explosions were televised as they took place.The accidents all resulted in severe damage to the reactor cores and releases of radioactivity to the environment despite heroic measures had taken by the operating personnel.The following paper provides some background into the development of these accidents and their root causes,chief among them,the prolonged station blackout conditions that isolated the reactors from their ultimate heat sink — the ocean.The interpretations given in this paper are summarized from a recently completed report funded by the United States Department of Energy (USDOE).

  19. Study on severe accident mitigation measures for the development of PWR SAMG

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In the development of the Severe Accident Management Guidelines (SAMG), it is very important to choose the main severe accident sequences and verify their mitigation measures. In this article, Loss-of-Coolant Accident (LOCA), Steam Generator Tube Rupture (SGTR), Station Blackout (SBO), and Anticipated Transients without Scram (ATWS) in PWR with 300 MWe are selected as the main severe accident sequences. The core damage progressions induced by the above-mentioned sequences are analyzed using SCDAP/RELAP5. To arrest the core damage progression and mitigate the consequences of severe accidents, the measures for the severe accident management (SAM) such as feed and bleed, and depressurizations are verified using the calculation. The results suggest that implementing feed and bleed and depressurization could be an effective way to arrest the severe accident sequences in PWR.

  20. Probabilistic risk assessment course documentation. Volume 1: PRA fundamentals

    International Nuclear Information System (INIS)

    The full range of PRA topics is presented, with a special emphasis on systems analysis and PRA applications. Systems analysis topics include system modeling such as fault tree and event tree construction, failure rate data, and human Reliability. The discussion of PRA applications is centered on past and present PRA based programs, such as WASH-1400 and the Interim Reliability Evaluation Program, as well as on some of the potential future applications of PRA. The relationship of PRA to generic safety issues such as station blackout and Anticipated Transient Without Scram (ATWS) is also discussed. In addition to system modeling, the major PRA tasks of accident process analysis, and consequence analysis are presented. An explanation of the results of these activities, and the techniques by which these results are derived, forms the basis for a discussion of these topics. An additional topic which is presented in this course is the topic of PRA management, organization, and evaluation. 84 figs., 41 tabs

  1. Core design and safety analyses of 600 MWt, 950 °C high temperature gas-cooled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Masaaki, E-mail: nakano-m@fujielectric.co.jp [Fuji Electric Co., Ltd., 1-1, Tanabe-shinden, Kawasaki-ku, Kawasaki-city 210-9530 (Japan); Takada, Eiji; Tsuji, Nobumasa; Tokuhara, Kazumi; Ohashi, Kazutaka; Okamoto, Futoshi [Fuji Electric Co., Ltd., 1-1, Tanabe-shinden, Kawasaki-ku, Kawasaki-city 210-9530 (Japan); Tazawa, Yujiro; Tachibana, Yukio [Japan Atomic Energy Agency, Oarai, Ibaraki-pref. 311-1393 (Japan)

    2014-05-01

    The conceptual core design study of high temperature gas-cooled reactor (HTGR) is performed. The major specifications are 600 MW thermal output, 950 °C outlet coolant temperature, prismatic core type, enriched uranium fuel. The decay heat in the core can be removed with only passive measures, for example, natural convection reactor cavity cooling system (RCCS), even if any electricity is not supplied (station blackout). The transient thermal analysis of the depressurization accident in the case the primary coolant decreases to the atmosphere pressure shows that the fuels and the reactor pressure vessel temperatures are kept under their safety limit criteria. The fission product release, Ag-110m and Cs-137 from the fuels under the normal operation is small as to make maintenance of devices in the primary cooling system, such as a gas turbine, without remote maintenance. The HTGRs can achieve the advanced safety features based on their inherent passive safety characteristics.

  2. A neural networks based ''trip'' analysis system for PWR-type reactors

    International Nuclear Information System (INIS)

    The analysis short after automatic shutdown (trip) of a PWR-type nuclear reactor takes a considerable amount of time, not only because of the great number of variables involved in transients, but also the various equipment that compose a reactor of this kind. On the other hand, the transients'inter-relationship, intended to the detection of the type of the accident is an arduous task, since some of these accidents (like loss of FEEDWATER and station BLACKOUT, for example), generate transients similar in behavior (as cold leg temperature and steam generators mixture levels, for example). Also, the sequence-of-events analysis is not always sufficient for correctly pin point the causes of the trip. (author)

  3. Development of tsunami-seismic PSA software for nuclear power plants in multi-unit site

    International Nuclear Information System (INIS)

    The large tsunami induced by the Great East Japan earthquakes on March 11, 2011 triggered the accidents at the Fukushima Dai-Ichi Nuclear Power Plant. The earthquake caused loss of off-site power and the tsunami failed most of the ultimate heat sink of the seawater pumps and on-site diesel generators and eventually DC batteries, resulting in station blackout (SBO), loss of core cooling and loss of reactor control. Because of insufficient preparedness against such severe accidents, three reactor cores damaged and large amount of radioactivity released to the environment. The primary lessons learned are enhancement of protective measures against severe accidents by external events, especially tsunami-seismic events. This paper describes development of tsunami-seismic PSA methods and sample analysis to gain some of risk insights and directions of PSA technology improvement. (author)

  4. Probabilistic risk assessment course documentation. Volume 1: PRA fundamentals

    Energy Technology Data Exchange (ETDEWEB)

    Breeding, R J; Leahy, T J; Young, J

    1985-08-01

    The full range of PRA topics is presented, with a special emphasis on systems analysis and PRA applications. Systems analysis topics include system modeling such as fault tree and event tree construction, failure rate data, and human Reliability. The discussion of PRA applications is centered on past and present PRA based programs, such as WASH-1400 and the Interim Reliability Evaluation Program, as well as on some of the potential future applications of PRA. The relationship of PRA to generic safety issues such as station blackout and Anticipated Transient Without Scram (ATWS) is also discussed. In addition to system modeling, the major PRA tasks of accident process analysis, and consequence analysis are presented. An explanation of the results of these activities, and the techniques by which these results are derived, forms the basis for a discussion of these topics. An additional topic which is presented in this course is the topic of PRA management, organization, and evaluation. 84 figs., 41 tabs.

  5. Control of Steam-Turbine Regulators at Transition to an Island State

    Science.gov (United States)

    Georgiev, Georgi

    2009-01-01

    The simple operating algorithm is presented for steam turbine regulators of type Simadin (Siemens) at emergency switching-off of the generator from system together with some, unknown in advance, load. The given situation is known as "a transition to an island state (regime)". Keeping of turbine speed and preservation of its rating value at a generator blackout when its own needs will be load only, is an easy problem. When the generator remains in its island it is necessary to solve "on-line" two additional problems: to reveal a situation "island" and to estimate the island load for translating a regulator on the new task and providing dynamic stability of transition. The algorithm was tried and entered successfully into practice on Varna TPP, CEZ GROUP (Prague), in 2008.

  6. Reliability analysis of emergency diesel generators of Kori Nuclear units 3 and 4

    International Nuclear Information System (INIS)

    This paper presents reliability analysis results and the insight gained for the emergency diesel generators (EDGs) of Kori Nuclear Power Units 3 and 4. Probabilistic safety assessment (PSA) for a nuclear power plant needs plant-specific data. In Kori Units 3 and 4 PSA, a station blackout sequence was judged to be the most dominant contributor to the core damage frequency. Therefore, there was an effort in plant-specific data collection and analysis on EDGs and Loss of Off-Site Power events. For the reliability analysis of EDG, the start failure probability, the repair time after start failure, and finally the maintenance unavailability are estimated based on the collected data. (author)

  7. Three-dimensional time-dependent star reactor kinetics analysis coupled with RETRAN and MCPWR system response

    International Nuclear Information System (INIS)

    The operation of a nuclear power plant must be continually supported by analyses which may include FSAR design basis and best-estimate thermal-hydraulic (T/H) and reactor dynamics analyses. The development and improvement of new analysis techniques provide many advantages including the capability to evaluate the impact of modeling assumptions made in previous rector kinetics and T/H calculations. The methodology presented in this paper shows how the time-dependent, three-dimensional reactor kinetics STAR nodal code can be directly coupled with the overall RCS T/H codes, RETRAN and MCPWR, in a tandem, iterative approach. This paper describes the results of using the RETRAN, MCPWR, and STAR codes in a tandem, predictive-corrective mode for three PWR transients: Loss of Feedwater Anticipated Transient Without Scram (ATWS); Station Blackout ATWS; and a Total Loss of Reactor Coolant System (RCS) Flow with a control rod scram

  8. Three-dimensional time-dependent STAR reactor kinetics analyses coupled with RETRAN and MCPWR system response

    International Nuclear Information System (INIS)

    The operation of a nuclear power plant must be regularly supported by various reactor dynamics and thermal-hydraulic analyses, which may include final safety analysis report (FSAR) design-basis calculations, and conservative and best-estimate analyses. The development and improvement of computer codes and analysis methodologies provide many advantages, including the ability to evaluate the effect of modeling simplifications and assumptions made in previous reactor kinetics and thermal-hydraulic calculations. This paper describes the results of using the RETRAN, MCPWR, and STAR codes in a tandem, predictive-corrective manner for three pressurized water reactor (PWR) transients: (a) loss of feedwater (LOF) anticipated transient without scram (ATWS), (b) station blackout ATWS, and (c) loss of total reactor coolant system (RCS) flow with a scram

  9. The California power crisis: the role for distributed generation

    International Nuclear Information System (INIS)

    This article examines the impact of the California power crisis on cogeneration and the on-site generation market, and highlights the plight of independent power generators including cogeneration facilities who have typically long-term contracts with the cash-strapped state electric utilities and have to defer maintenance due to unpaid bills. The move towards distributed generation, the efforts to increase backup diesel-fired generation during blackouts, and the government's efforts to encourage distributed energy are discussed along with the concerns of air quality regulators with on-site generation emissions, and the impact of the California crisis on the future of distributed energy. The growing role of distributed energy in meeting demand and holding down costs is explored, and the expanding market for microturbines is noted

  10. Fukushima. The accident sequence and important causes. Pt. 2/3; Fukushima. Unfallablauf und wesentliche Ursachen. T. 2/3

    Energy Technology Data Exchange (ETDEWEB)

    Pistner, Christoph [Oeko-Institut e.V., Darmstadt (Germany). Bereich Nukleartechnik und Anlagensicherheit

    2013-07-01

    In this part on the accident sequence in the NPP Fukushima Daiichi on March 11, 2011 the important safety systems of a nuclear power plant are described, including the design of a nuclear boiling water reactor with Mark-II type containment, the high-pressure injection system and the systems for afterheat removal. The chronology of the accident progress in the NPP units 1-3 is described. The units 4-6 were shutdown due to revision work. Due to the earthquake an electric power transformation station close to the NPP site and the power poles were destroyed, the redundant power supply of the neighboring electricity supplier Tohoku did not work. All emergency diesel generators were flooded and destroyed resulting in the so-called station blackout. Firefighting trucks and materials for radiation protection and the infrastructure at the NPP site were destroyed. The release of radioactivity induced a severe contamination of the reactor site.

  11. We Detect Blue Light Phenomena Correlating with Environmental and Weather Changes, and Historic Native American/span>s or Their Place Names.

    Science.gov (United States)

    Ochs, Michael Ann; Mc Leod, Roger D.; Mc Leod, Edward M.

    2003-10-01

    Katahdin (Christ Cathar Spirit-signal stronghold) in Maine is sacred to the Penobscot Indian Nation. That mountain complex, and areas like Ellis Pond, ME and Penley Hill/Anasagunticook (adherent of Jesus Christ Spirit-signal doctor church) of the Mexico/Rumford/Mountain Valley region, also in Maine, have an association with historic Native Americans like the medicine woman Molocket/Molly Ockett. We have observed that these and other regions generate electromagnetic field (EMF) signals, which we can detect visually and in other ways. Such signals have sometimes been associated with significant and dynamic weather phenomena. Ohio's Serpent Mound and associated regions, or those now occupied by the Hopi Indian Nation, formerly an ancient Anasazi site, or areas of the current and earlier Mayan Nations, or the Nazca Plateau of Peru, may generate signals correlating with climate change, that may impact our technology, as in major power blackouts.

  12. Sizewell 'dirty tricks'

    International Nuclear Information System (INIS)

    The pro-nuclear lobby is accused of dubious tactics to promote their case for the Sizewell-B reactor. These include reassessing future electricity demand which, it is claimed, could only be met by nuclear power, claiming that new power stations were needed to avoid blackouts during cold spells, and the reporting of a major design fault in the control rods of the Torness and Heysham AGR stations. The latter is felt to be related to the promotion by the South of Scotland Electricity Board of the AGR case, as opposed to the Central Electricity Generating Board's advocation of a PWR reactor design. The author argues for a series of coal-fired power stations instead, and a major energy conservation programme. (UK)

  13. The equal load-sharing model of cascade failures in power grids

    CERN Document Server

    Scala, Antonio

    2015-01-01

    Electric power-systems are one of the most important critical infrastructures. In recent years, they have been exposed to extreme stress due to the increasing demand, the introduction of distributed renewable energy sources, and the development of extensive interconnections. We investigate the phenomenon of abrupt breakdown of an electric power-system under two scenarios: load growth (mimicking the ever-increasing customer demand) and power fluctuations (mimicking the effects of renewable sources). Our results indicate that increasing the system size causes breakdowns to become more abrupt; in fact, mapping the system to a solvable statistical-physics model indicates the occurrence of a first order transition in the large size limit. Such an enhancement for the systemic risk failures (black-outs) with increasing network size is an effect that should be considered in the current projects aiming to integrate national power-grids into "super-grids".

  14. Cascading Power Outages Propagate Locally in an Influence Graph that is not the Actual Grid Topology

    CERN Document Server

    Hines, Paul D H; Rezaei, Pooya

    2015-01-01

    In a cascading power transmission outage, component outages propagate non-locally; after one component outages, the next failure may be very distant, both topologically and geographically. As a result, simple models of topological contagion do not accurately represent the propagation of cascades in power systems. However, cascading power outages do follow patterns, some of which are useful in understanding and reducing blackout risk. This paper describes a method by which the data from many cascading failure simulations can be transformed into a graph-based model of influences that provides actionable information about the many ways that cascades propagate in a particular system. The resulting "influence graph" model is Markovian, since component outage probabilities depend only on the outages that occurred in the prior generation. To validate the model we compare the distribution of cascade sizes resulting from n-2 contingencies in a 2896 branch test case to cascade sizes in the influence graph. The two dist...

  15. Optimizing the robustness of electrical power systems against cascading failures

    CERN Document Server

    Zhang, Yingrui

    2016-01-01

    Electrical power systems are one of the most important infrastructures that support our society. However, their vulnerabilities have raised great concern recently due to several large-scale blackouts around the world. In this paper, we investigate the robustness of power systems against cascading failures initiated by a random attack. This is done under a simple yet useful model based on global and equal redistribution of load upon failures. We provide a complete understanding of system robustness by i) deriving an expression for the final system size as a function of the size of initial attacks; ii) deriving the critical attack size after which system breaks down completely; iii) showing that complete system breakdown takes place through a first-order (i.e., discontinuous) transition in terms of the attack size; and iv) establishing the optimal load-capacity distribution that maximizes robustness. In particular, we show that robustness is maximized when the difference between the capacity and initial load is...

  16. Network science quantification of resilience demonstrated on the Indian Railways Network

    CERN Document Server

    Bhatia, Udit; Kodra, Evan; Ganguly, Auroop R

    2015-01-01

    The structure, interdependence, and fragility of systems ranging from power grids and transportation to ecology, climate, biology and even human communities and the Internet, have been examined through network science. While the response to perturbations has been quantified, recovery strategies for perturbed networks have usually been either discussed conceptually or through anecdotal case studies. Here we develop a network science-based quantitative methods framework for measuring, comparing and interpreting hazard responses and as well as recovery strategies. The framework, motivated by the recently proposed temporal resilience paradigm, is demonstrated with the Indian Railways Network. The methods are demonstrated through the resilience of the network to natural or human-induced hazards and electric grid failure. Simulations inspired by the 2004 Indian Ocean Tsunami and the 2012 North Indian blackout as well as a cyber-physical attack scenario. Multiple metrics are used to generate various recovery strateg...

  17. Model and Algorithm for the Optimal Controlled Partitioning of Power Systems

    Institute of Scientific and Technical Information of China (English)

    LIN Jikeng; LI Shengwen; WU Peng; WANG Xudong; SHAO Guanghui; XU Xingwei; MA Xin

    2012-01-01

    In China, with the development of projects such as "electricity transmission from the West to the East" and "power exchange between the South and the North", and with the UHV project being put into operation, a nation-wide interconnection system has been formed. For such big interconnection system, local faults or disturbances might lead to large-scale power blackouts and even system collapses, which will cause direct and indirect losses comparable to a big natural disaster. By taking proper and reasonable controlled partition measures, the risk of long-period and large-area power failure and even system collapse will be greatly reduced. However, with the system size increasing, the number of partition interface will grow geometrically, and therefore, it is a great challenge for a nation-wide interconnection system to achieve the optimal partition surface.

  18. Total loss of AC power analysis for EPR reactor

    Energy Technology Data Exchange (ETDEWEB)

    Darnowski, Piotr, E-mail: piotr.darnowski@itc.pw.edu.pl [Warsaw University of Technology, Institute of Heat Engineering, Nowowiejska 21/25, 00-665 Warsaw (Poland); Skrzypek, Eleonora, E-mail: eleonora.skrzypek@ncbj.gov.pl [Warsaw University of Technology, Institute of Heat Engineering, Nowowiejska 21/25, 00-665 Warsaw (Poland); National Centre for Nuclear Research (NCBJ), A. Sołtana 7, 05-400 Otwock-Świerk (Poland); Mazgaj, Piotr, E-mail: piotr.mazgaj@itc.pw.edu.pl [Warsaw University of Technology, Institute of Heat Engineering, Nowowiejska 21/25, 00-665 Warsaw (Poland); Świrski, Konrad [Warsaw University of Technology, Institute of Heat Engineering, Nowowiejska 21/25, 00-665 Warsaw (Poland); Gandrille, Pascal [AREVA NP SAS, Tour AREVA, 1 place Jean Millier, 92084 Paris La Défense (France)

    2015-08-15

    Highlights: • Total loss of AC power (Station Blackout) was simulated for the EPR reactor model. • In-vessel phase of the accident is under consideration. • Comparison of MELCOR and MAAP results is presented. • MELCOR and MAAP results are comparable. - Abstract: In this paper the results of severe accident simulations for the EPR reactor in the case of loss of offsite power combined with total failure of all diesel generators (total loss of AC power) are presented. Calculations were performed with MELCOR 2.1 computer code for in-vessel phase of the accident. In this scenario, the unavailability of all offsite and onsite power sources and the lack of cooling leads directly to core degradation, material relocation to the lower plenum and rupture of the reactor pressure vessel. MELCOR results were compared qualitatively and quantitatively with MAAP4 code results and show a good agreement.

  19. Analysis of Qinshan Nuclear Power Base Emergency Mobile Power Configuration%秦山核电基地应急移动电源配置分析

    Institute of Scientific and Technical Information of China (English)

    王贵良

    2016-01-01

    应急移动电源是核电厂在全厂断电工况下,保证反应堆堆芯冷却的重要手段。本文对秦山核电基地应急移动电源的配置进行了论述和分析,其对国内其他核电厂的应急移动电源配置也具有一定的参考价值。%Emergency mobile power supply is an important means for the nuclear power plant to ensure the cooling of the reactor core while station blackout (SBO). This article analyzes the configuration of Qinshan Nuclear Power Base emergency mobile power, which has referential and practical value for other domestic nuclear power plant emergency mobile power supply configuration.

  20. KBZ-400型馈电开关落锁装置的设计与应用

    Institute of Scientific and Technical Information of China (English)

    邢永鹤; 闫丕江; 谭波

    2015-01-01

    in order to ensure the safety of staff, KBZ-400 switch lock linkage. Electrical equipment failure, repair stations and placed 400-feeding switch is not in the same location, personnel mistakenly transmission can cause insecurity to maintenance personnel will feed switch hands after the blackout hit, plus a locking lever lock up installation.%为了保证维修工作人员的安全,KBZ-400开关设置了闭锁联动装置。电气设备出现故障时,维修地点与放置400型馈电开关不在同一位置,人员的误送电会给维修人员造成不安全因素,将馈电开关手把打到停电位置后,再加一套闭锁杆的落锁装置。

  1. WASA-BOSS. ATHLET-CD model for severe accident analysis for a generic KONVOI reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tusheva, Polina; Schaefer, Frank; Kozmenkov, Yaroslav; Kliem, Soeren [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany). Reactor Safety Div.; Hollands, Thorsten [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Garching (Germany); Trometer, Ailine; Buck, Michael [Stuttgart Univ. (Germany). Dept. of Reactor Safety, Systems and Environment

    2015-07-15

    Within the scope of the ongoing joint research project WASA-BOSS (Weiterentwicklung und Anwendung von Severe Accident Codes - Bewertung und Optimierung von Stoerfallmassnahmen) an ATHLET-CD model for investigation of severe accident scenarios has been developed. The model represents a generic pressurized water reactor (PWR) of type KONVOI. It has been applied for analyzing selected hypothetical core degradation scenarios, considering application of countermeasures and accident management measures, during the early phase of an accident, as well as the late in-vessel phase, when the core degradation process has already begun. Possible accident management measures for loss of coolant (LOCA) and station blackout (SBO) scenarios are discussed. This paper focuses on the ATHLET-CD model development and results from selected simulations for a SBO scenario without and with application of countermeasures.

  2. Study on the electromagnetic waves propagation characteristics in partially ionized plasma slabs

    Directory of Open Access Journals (Sweden)

    Zhi-Bin Wang

    2016-05-01

    Full Text Available Propagation characteristics of electromagnetic (EM waves in partially ionized plasma slabs are studied in this paper. Such features are significant to applications in plasma antennas, blackout of re-entry flying vehicles, wave energy injection to plasmas, and etc. We in this paper developed a theoretical model of EM wave propagation perpendicular to a plasma slab with a one-dimensional density inhomogeneity along propagation direction to investigate essential characteristics of EM wave propagation in nonuniform plasmas. Particularly, the EM wave propagation in sub-wavelength plasma slabs, where the geometric optics approximation fails, is studied and in comparison with thicker slabs where the geometric optics approximation applies. The influences of both plasma and collisional frequencies, as well as the width of the plasma slab, on the EM wave propagation characteristics are discussed. The results can help the further understanding of propagation behaviours of EM waves in nonuniform plasma, and applications of the interactions between EM waves and plasmas.

  3. Utilization of risk information for reprocessing facilities

    International Nuclear Information System (INIS)

    A procedure of probabilistic safety assessment (PSA) for a reprocessing facility has been under the development aiming to utilize risk information for safety regulations in this project. The procedure has been developed through performing a PSA of a model plant for various events, which are taken into consideration in a safety design, and other activities. An outline of results during fiscal year 2011 is described in the paper. A background and a purpose of the project are given in the chapter 1. A major result during 2011 is an accomplishment of summarization of PSA procedure for two events, i.e. station blackout and fall of spent fuel assembly. Those results are outlined in the chapter 2. Other than the summarization of PSA procedure PSAs of a model plant for two events due to an earthquake and studies related to the PSA procedure were carried out. (author)

  4. On engineering implementation of the digital power system

    Institute of Scientific and Technical Information of China (English)

    HE GuangYu; SUN YingYu; CHANG NaiChao; MEI ShengWei

    2008-01-01

    The narrow definition of the digital power system (DPS) is proposed. The architec-ture, features and key contents of the DPS are presented, which include intelligent dispatching system, hybrid automatic control system and data sharing platform. The successful construction of the DPS can greatly improve the performances of power system operating and dispatching, which mainly reflect s fundamental in-crease of the ability of avoiding catastrophes resulting from blackouts of power supply, a significant improvement of economic efficiency of power system opera-tion, and an improvement of decision efficiency of power system developing. The DPS describes a vision of the development of power system end the way to achieve this vision. At the same time, the paper also proposes the principles of the design and implementation of the DPS.

  5. SOSPO-SP: Secure Operation of Sustainable Power Systems Simulation Platform for Real-Time System State Evaluation and Control

    DEFF Research Database (Denmark)

    Morais, Hugo; Vancraeyveld, Pieter; Pedersen, Allan Henning Birger;

    2014-01-01

    -time simulation in closed-loop is essential to develop and validate new real-time applications of wide-area PMU data. This paper presents a simulation platform developed within the research project Secure Operation of Sustainable Power Systems (SOSPO). The SOSPO simulation platform (SOSPO-SP) functions in a...... closed-loop, integrating new real-time assessment methods to provide useful information to operators in power system control centers and to develop new control methodologies that handle emergency situations and avoid power system blackouts....... Measurement Units (PMUs) provides more information and enables wide-area monitoring with accurate timing. One of the challenges in the near future is converting the high quantity and quality of information provided by PMUs into useful knowledge about operational state of a global system. The use of real...

  6. Transmission Properties of Radar Wave through Reentry Plasma Sheath

    Institute of Scientific and Technical Information of China (English)

    GAO Zheng-ping; MA Zhao-guo; LIU Jing; LI Zhong-ping; ZHANG Da-hai

    2007-01-01

    In this paper, by taking into account the coupling of the ionization of ablation gas and atmosphere, an electrons density distribution model is built. Using this model, the transmission properties of different polarization radar wave through sheath are evaluated on the basis of the transmission matrix theory. Then, we discuss the effects of the electrons density, the added magnetic field, and the radar wave frequency on the transmission properties. As a result of this investigation,greater transmission power could be gained in order to efficiently shorten communication blackout,by reducing the electrons density or choosing proper added magnetic field and the frequency of the radar wave according to the different polarization form of the radar wave.

  7. Security assessment for intentional island operation in modern power system

    DEFF Research Database (Denmark)

    Chen, Yu; Xu, Zhao; Østergaard, Jacob

    2011-01-01

    operator can clearly know if it is suitable to conduct island operation at one specific moment. Besides, in order to improve the computation efficiency, the Artificial Neural Network (ANN) is applied for fast ISR formation. Thus, online application of ISR based islanding security assessment could...... the emergency in the power system, some distribution networks may be intentionally separated from the main grid to avoid complete system collapse. If DGs in those networks could continuously run instead of immediately being shut down, the blackout could be avoided and the reliability of supply could...... be increased. However, when to island or how to ensure the islanded systems can survive the islanding transition is uncertain. This article proposes an Islanding Security Region (ISR) concept to provide security assessment of island operation. By comparing the system operating state with the ISR, the system...

  8. Differences in results for MAAP4.0.5 sample input execution on PCs with different operating systems

    International Nuclear Information System (INIS)

    Differences in the results occur when a typical severe accident sample case such as, SBLOCA (small break LOCA) and SBO (station Blackout) are executed with MAAP 4.0.5 (Windows version) on Windows 2003 versus the same run on Windows XP on different machines. Some results, like as a hydrogen mass released, are different. Small differences exist between two independent runs of a single severe accident sample case on a single machine. NPP Krsko repeated MAAP 4.0.5 calculation for the SBLOCA as most important Reactor vessel failure sequences on different machines and with Windows version MAAP 4.0.5 on Windows 2000 and Windows XP version of MAAP 4.0.5. (author)

  9. On engineering implementation of the digital power system

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The narrow definition of the digital power system (DPS) is proposed. The architec- ture, features and key contents of the DPS are presented, which include intelligent dispatching system, hybrid automatic control system and data sharing platform. The successful construction of the DPS can greatly improve the performances of power system operating and dispatching, which mainly reflect a fundamental in- crease of the ability of avoiding catastrophes resulting from blackouts of power supply, a significant improvement of economic efficiency of power system opera- tion, and an improvement of decision efficiency of power system developing. The DPS describes a vision of the development of power system and the way to achieve this vision. At the same time, the paper also proposes the principles of the design and implementation of the DPS.

  10. Clinical Assessment of Cardiovascular and Autonomic Function

    Directory of Open Access Journals (Sweden)

    Diego Benitez

    2004-10-01

    Full Text Available This paper presents a non-invasive virtual medical instrument for the clinical assessment of cardiovascular and autonomic function. The virtual instrument was developed with the aim of analysing and understanding the physiological changes that occurs in the heart and circulation during vasovagal blackout attacks. The automated virtual instrument allows impedance cardiography analysis, time and frequency heart rate and blood pressure variability analysis, invasive and non-invasive baroreflex sensitivity assessment and forearm blood flow measurements. Using this virtual instrument five control subjects (3 male, mean age 30.6 ± 5.4 and five vasovagal syncope suffers (2 male, mean age 38.6 ± 6.3 were used in a study to try to identify the differences between the two groups to tilt induced syncope. The results obtained suggest that there are fundamental differences in the physiological responses to orthostatic stress between vasovagal patients and controls, which are evident before the onset of major haemodynamic changes.

  11. City of Hoboken Energy Surety Analysis: Preliminary Design Summary

    Energy Technology Data Exchange (ETDEWEB)

    Stamp, Jason Edwin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Military and Energy Systems Analysis Dept.; Baca, Michael J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Military and Energy Systems Analysis Dept.; Munoz-Ramos, Karina [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Military and Energy Systems Analysis Dept.; Schenkman, Benjamin L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Military and Energy Systems Analysis Dept.; Eddy, John P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Systems Readiness and Sustainment Technology Dept.; Smith, Mark A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Systems Readiness and Sustainment Technology Dept.; Guttromson, Ross [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Electric Power Systems Research Dept.; Henry, Jordan M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Critical Infrastructure Systems Dept.; Jensen, Richard Pearson [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Geomechanics Dept.

    2014-09-01

    In 2012, Hurricane Sandy devastated much of the U.S. northeast coastal areas. Among those hardest hit was the small community of Hoboken, New Jersey, located on the banks of the Hudson River across from Manhattan. This report describes a city-wide electrical infrastructure design that uses microgrids and other infrastructure to ensure the city retains functionality should such an event occur in the future. The designs ensure that up to 55 critical buildings will retain power during blackout or flooded conditions and include analysis for microgrid architectures, performance parameters, system control, renewable energy integration, and financial opportunities (while grid connected). The results presented here are not binding and are subject to change based on input from the Hoboken stakeholders, the integrator selected to manage and implement the microgrid, or other subject matter experts during the detailed (final) phase of the design effort.

  12. Sodium Experiments on Natural Circulation Decay Heat Removal and 3D Simulation of Plenum Thermal Hydraulics

    International Nuclear Information System (INIS)

    Natural circulation decay heat removal is one of the significant issues for fast reactor safety, especially in long term station blackout events. Several sodium experiments were carried out using a 7-subassembly core model for core thermal hydraulics under natural circulation conditions and for onset transients of natural circulation in a decay heat removal system (DHRS) including natural draft. Significant heat removal via inter-wrapper flow was confirmed in the experiments. Solidification of sodium in an air cooler is one of key issues in loss of heat sink events. Natural circulation characteristics under long-term decay heat removal were also obtained. Multi-dimensional phenomena, e.g., thermal stratification and bypass flow in plenums and/or heat exchangers, may influence the natural circulation. Thus, 3D simulation method was developed for entire region in the primary loop. Comparison of temperature distributions in a DHRS heat exchanger between experiment and analysis was done. (author)

  13. Experimental measurement and interpretation of natural circulation two-phase flow signals in a vertically heated channel during flashing induced oscillations

    International Nuclear Information System (INIS)

    Two-phase natural circulation is a passive heart transport system with a highly efficient heat transfer mechanism. Primary heat transport systems of advanced reactors incorporate these passive systems due to their simplicity in design and their availability for longer durations even under conditions of complete station black-out. The two-phase flow observed in a vertical channel at low pressures, involves more than one oscillatory mode in time and space, due to the inherent nonlinear and non stationary nature of the phenomena. The industrial measurement of flow in any vertically heated natural circulation channel is carried out at one location in the entire loop by design and hence captures the dynamics due to oscillatory contents, evolved in that measuring instant in the channel, as well as that of the time dependent spatially displaced oscillations, due to the channel flow. (author)

  14. Comparison of a Traditional Probabilistic Risk Assessment Approach with Advanced Safety Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Curtis L; Mandelli, Diego; Zhegang Ma

    2014-11-01

    As part of the Light Water Sustainability Program (LWRS) [1], the purpose of the Risk Informed Safety Margin Characterization (RISMC) [2] Pathway research and development (R&D) is to support plant decisions for risk-informed margin management with the aim to improve economics, reliability, and sustain safety of current NPPs. In this paper, we describe the RISMC analysis process illustrating how mechanistic and probabilistic approaches are combined in order to estimate a safety margin. We use the scenario of a “station blackout” (SBO) wherein offsite power and onsite power is lost, thereby causing a challenge to plant safety systems. We describe the RISMC approach, illustrate the station blackout modeling, and contrast this with traditional risk analysis modeling for this type of accident scenario. We also describe our approach we are using to represent advanced flooding analysis.

  15. Node seniority ranking

    CERN Document Server

    Fioriti, Vincenzo

    2014-01-01

    Recent advances in graph theory suggest that is possible to identify the oldest nodes of a network using only the graph topology. Here we report on applications to heterogeneous real world networks. To this end, and in order to gain new insights, we propose the theoretical framework of the Estrada communicability. We apply it to two technological networks (an underground, the diffusion of a software worm in a LAN) and to a third network representing a cholera outbreak. In spite of errors introduced in the adjacency matrix of their graphs, the identification of the oldest nodes is feasible, within a small margin of error, and extremely simple. Utilizations include the search of the initial disease-spreader (patient zero problem), rumors in social networks, malware in computer networks, triggering events in blackouts, oldest urban sites recognition.

  16. Catalogue of requirements for a plant-specific safety inspection of German nuclear power plants taking into account the Fukushima-I (Japan) events

    International Nuclear Information System (INIS)

    The catalogue of requirements for a plant-specific safety inspection of German nuclear power plants taking into account the Fukushima-I (Japan) events worked out by the German RSK (reactor safety commission) includes the following inspection topics: natural events like earth quakes, floods, weather-based consequences and possible superposition; civilization-based events like airplane crash, gas release, reactor accident consequences for neighboring units, terroristic impacts, external attacks on computer-based control systems. Further event-independent assumptions have to be considered: station blackout, long-term emergency power supply requirement, failure of auxiliary cooling water supply, efficacy of preventive measures, aggravating boundary conditions for the performance of emergency measures.

  17. What organizations did (and didn't) do: Three factors that shaped conservation responses to California's 2001 'crisis'

    Energy Technology Data Exchange (ETDEWEB)

    Janda, Kathryn; Payne, Christopher; Kunkle, Rick; Lutzenhiser, Loren

    2002-08-18

    Beginning in the summer of 2000, California experienced energy supply problems, sharp increases in electricity and natural gas prices, and isolated blackouts. In response, California's state government implemented an unprecedented energy conservation effort to mitigate projected electricity supply shortages during the summer of 2001. Ultimately, significant electricity demand and consumption reductions were achieved. This paper considers the response of commercial and institutional organizations to the California energy situation and offers a description of three factors that shaped these responses: (1) concern about energy problems; (2) operational conditions; and (3) institutional capacity for action. A matrix of possible combinations of concern, conditions, and capacity offers a heuristic for use in exploring how to best tailor and target policy interventions to the circumstances of particular subgroups of organizations.

  18. Risk energy transition. Ways out of the impasse; Risiko Energiewende. Wege aus der Sackgasse

    Energy Technology Data Exchange (ETDEWEB)

    Kleinknecht, Konrad [Muenchen Univ., Garching (Germany). Fakultaet fuer Physik

    2015-07-01

    The exit of the use of nuclear energy in Germany, it was decided in the summer of 2011 in a rush. Now it is becoming obvious that there is no realistic plan for the conversion of energy supply in the envisaged deadline of ten years. For the conversion of our entire power supply and therefore our economy the period is too short. It lacks a robust empirical reason that have to deal with the issues of security of supply, the affordability, the impact on economic development and social justice. Thus, this treansition threatens to fail at their contradictions. Konrad Kleinknecht tries in his book, to name the problems and to find answers. For him, arise the following questions: What are our opportunity to replace with wind and solar power to replace a part of the power supply? What power sources provide secured capacity? Can we dispense with coal-fired plants? Do we need new power lines? How power may be stored? How real is the risk of blackouts in windless nights? Will the power prices continue to rise? Can be avoided the major risks of the energy transition with a fundamental reform of the Renewable Energies Act (EEG)? The power supply must serve the common good and benefit the industrial site Germany. A blackout would be a disaster for the whole country, it must be avoided at all events. How can we manage this, the author present in his evocative book. [German] Der Ausstieg aus der Nutzung der Kernenergie in Deutschland wurde im Sommer 2011 im Eiltempo beschlossen. Jetzt zeigt sich, dass es keinen realistischen Plan fuer den Umbau der Energieversorgung in der vorgesehenen Frist von zehn Jahren gibt. Fuer die Umstellung unserer gesamten Stromversorgung und damit unserer Wirtschaft ist der Zeitraum zu kurz. Es fehlt eine belastbare empirische Begruendung, die Fragen der Versorgungssicherheit, der Finanzierbarkeit, der Auswirkungen auf die wirtschaftliche Entwicklung und die soziale Gerechtigkeit behandeln muesste. Somit droht diese Wende an ihren Widerspruechen zu

  19. Design and development of self-powered sensors on wireless sensor network for standalone plant critical data management during SBO and beyond design basis events

    International Nuclear Information System (INIS)

    Advanced reactors are designed with an aim of maximum safety, optimized fuel utilization and effective system design. Safety aspects in reactor designs are being viewed for all possible vulnerabilities, and as a result, robust self-regulating passive safety features have been favored in Gen IV and advanced reactor designs. In addition to passive systems, the accidents scenarios at Fukushima indicate the dire need of reliable and stand-alone self-powered sensors, for monitoring plant critical parameters for effective damage control actions. There is a strong need for plant critical data management and situation awareness during the unavailability of all conventional power sources in a nuclear power plant, during extended station blackout (SBO) conditions. These self-powered sensors would assist the operators in managing events like SBO and help in containing any Beyond Design Basis Events (BDBE) conditions, well away from the public domain

  20. Analysis of core damage frequency from internal events: Surry, Unit 1

    International Nuclear Information System (INIS)

    This document contains the accident sequence analyses for Surry, Unit 1; one of the reference plants being examined as part of the NUREG-1150 effort by the Nuclear Regulatory Commission (NRC). NUREG-1150 will document the risk of a selected group of nuclear power plants. As part of that work, this report contains the overall core damage frequency estimate for Surry, Unit 1, and the accompanying plant damage state frequencies. Sensitivity and uncertainty analyses provide additional insights regarding the dominant contributors to the Surry core damage frequency estimate. The numerical results are driven to some degree by modeling assumptions and data selection for issues such as reactor coolant pump seal LOCAs, common cause failure probabilities, and plant response to station blackout and loss of electrical bust initiators. The sensitivity studies explore the impact of alternate theories and data on these issues