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. Blackouts and natural risks

    Science.gov (United States)

    Danihelka, P.; Paldusová, E.; Dobeš, P.

    2009-04-01

    "Blackout" has become the common definition for the situation when electricity supply and demand are not balanced and security of supply fails. These failures have many impacts besides the lights going out, but this term is used commonly. Blackouts have drastic impacts for the society on whole and its citizens and some of them can influence big areas and last for long period, so the consequences are catastrophic. Even if at the European scale, the large extend blackouts are supposed to be exceptional, real frequency is relatively high, approximately once per two years. According to statistics, blackouts are often caused by natural causes, especially lightning. An example of lightning caused blackout is New York blackout 1977, leading to the stand-by of nuclear power plant Indian Point and with overall cost more than 300 mil. USD. There is a clear a distinction between those blackouts caused by nature and those that were caused by other faults. Usually, the nature-caused disturbances as Canada 1988, Sweden 2005 and France 1999, stay inside one country. However, their duration can extend to several weeks, and thus the costs of the interruptions and social impacts are high. Blackouts of only technologic and/or anthropogenic origin are frequently shorter, but may concern more end-users, when cascading from one country to another. Lightning is not the only natural event causing blackouts. Eighteen various case studies of blackout caused by natural events different then lightning were studied and following natural phenomenon found as a root causes: 1x forest fire, 1x snow calamity, 1x ice storm, 1x landslide, 1x high temperature, 1x geomagnetic storm, 2x earthquake, 2x inundation, 2x contact of line with trees, 6x storm (wind, hurricane…). We can conclude, that natural event are frequent cause of blackout of medium or large extend and this phenomena should be studied more in details. This contribution was supported by Ministry of Environment of the Czech Republic.

  3. 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.

  4. 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...

  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. 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.

  7. 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...

  8. 77 FR 16175 - Station Blackout

    Science.gov (United States)

    2012-03-20

    ... Rulemaking on Station Blackout Due to Coronal Mass Ejection D. Mitigating Strategies IV. Discussion and... petition for rulemaking (PRM), PRM-50-101 (76 FR 58165) as a way to address SBO mitigation. The approach... predecessor to the NRC, had yet to develop generic requirements for facility design criteria at that time....

  9. 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...

  10. 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...

  11. 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...

  12. 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 ...

  13. Blackouts, risk, and fat-tailed distributions

    CERN Document Server

    Weron, R; Simonsen, Ingve; Weron, Rafal

    2005-01-01

    We analyze a 19-year time series of North American electric power transmission system blackouts. Contrary to previously reported results we find a fatter than exponential decay in the distribution of inter-occurrence times and evidence of seasonal dependence in the number of events. Our findings question the use of self-organized criticality, and in particular the sandpile model, as a paradigm of blackout dynamics in power transmission systems. Hopefully, though, they will provide guidelines to more accurate models for evaluation of blackout risk.

  14. 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

  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. 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...

  17. 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...

  18. 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…

  19. Navigation strategy with the spacecraft communications blackout for Mars entry

    Science.gov (United States)

    Wang, Xichen; Xia, Yuanqing

    2015-02-01

    Future Mars missions require precision entry navigation capability, especially in the presence of communications blackout. On the mission of Mars Science Laboratory (MSL), there was a 70-s communications blackout period during atmospheric entry phase. In allusion to the spacecraft communications blackout encountered, this paper predicts an upper-bound for any possible blackout period firstly, improves the default integrated navigation measurements based on IMU and surface radiometric beacons, and proposes innovative attitude observation model based on IMU and range observation model based on orbiters finally. To verify the accuracy and effectiveness of the proposed observation models in the presence of communications blackout, unscented Kalman filter is utilized to demonstrate the navigation performance. The results show that navigation errors based on improved observation models proposed in this paper degrade an order of magnitude compared with the default observation models even if the communications blackout takes place, which satisfies the requirements of future Mars landing missions.

  20. 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...

  1. 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.

  2. 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

  3. 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.

  4. 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)

  5. 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.

  6. 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).

  7. 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

  8. 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

  9. 29 CFR 2520.101-3 - Notice of blackout periods under individual account plans.

    Science.gov (United States)

    2010-07-01

    ... beneficiaries pursuant to paragraph (b) of this section. (d) Definitions. For purposes of this section— (1... three consecutive business days. (ii) Exclusions. The term “blackout period” does not include a... otherwise available under the plan, is called a “blackout period.” Whether or not you are...

  10. 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)

  11. 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

  12. 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.

  13. 47 CFR 76.120 - Network non-duplication protection, syndicated exclusivity and sports blackout rules for...

    Science.gov (United States)

    2010-10-01

    ... exclusivity and sports blackout rules for satellite carriers: Definitions. 76.120 Section 76.120... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.120 Network non-duplication protection, syndicated exclusivity and sports blackout rules...

  14. 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.

  15. 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.)

  16. 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.

  17. 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

  18. 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

  19. Choice in a variable environment: effects of blackout duration and extinction between components.

    Science.gov (United States)

    Davison, Michael; Baum, William M

    2002-01-01

    Pigeons were trained in a procedure in which sessions included seven four- or 10-reinforcer components, each providing a different reinforcer ratio that ranged from 27:1 to 1:27. The components were arranged in random order, and no signals differentiated the component reinforcer ratios. Each condition lasted 50 sessions, and the data from the last 35 sessions were analyzed. Previous results using 10-s blackouts between components showed some carryover of preference from one component to the next, and this effect was investigated in Experiment 1 by varying blackout duration from 1 s to 120 s. The amount of carryover decreased monotonically as the blackout duration was lengthened. Preference also decreased between reinforcers within components, suggesting that preference change during blackout might follow the same function as preference change between reinforcers. Experiment 2 was designed to measure preference change between components more directly and to relate this to preference change during blackout. In two conditions a 60-s blackout occurred between components, and in two other conditions a 60-s period of unsignaled extinction occurred between components. Preference during the extinction period progressively fell toward indifference, and the level of preference following extinction was much the same as that following blackout. Although these results are consistent with Davison and Baum's (2000) theory of the effects of reinforcers on local preference, other findings suggest that theory is incomplete: After a sequence of reinforcers from one alternative, some residual preference remained after 60 s of extinction or blackout, indicating the possibility of an additional longer term accumulation of reinforcer effects than originally suggested. PMID:11831784

  20. 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

  1. 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)

  2. 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)

  3. 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.

  4. The August 14,2003 blackout and its importance to China

    Institute of Scientific and Technical Information of China (English)

    P. Jeffrey Palermo

    2004-01-01

    Combining news reports and comments from American circles and according to the Interim Report presented by the August 14 blackout task force,the process and reasons of the blackout were summed up. It was pointed out that due to some new problems caused by American power deregulation such as the weak coordination and control for long distance power transfers, the possibility of blackouts has been increased. The rapid economic development in eastern China sets high requirement for the development of power system.Therefore the current power system in China should be re-evaluated and re-analyzed regularly while the "breakpoints" within the transmission system should be considered in planning and designing to ensure islands operation in time of emergency.

  5. 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.

  6. 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

  7. 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.

  8. Control and prediction for blackouts caused by frequency collapse in smart grids

    Science.gov (United States)

    Wang, Chengwei; Grebogi, Celso; Baptista, Murilo S.

    2016-09-01

    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 strategies show the efficient function of the fast-response energy storage systems in preventing and predicting blackouts in smart grids. This work provides innovative ideas which help us to build up a robuster and more economic smart power system.

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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)

  16. 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 ...

  17. 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...

  18. 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

  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. Review of Leading Approaches for Mitigating Hypersonic Vehicle Communications Blackout and a Method of Ceramic Particulate Injection Via Cathode Spot Arcs for Blackout Mitigation

    Science.gov (United States)

    Gillman, Eric D.; Foster, John E.; Blankson, Isaiah M.

    2010-01-01

    Vehicles flying at hypersonic velocities within the atmosphere become enveloped in a "plasma sheath" that prevents radio communication, telemetry, and most importantly, GPS signal reception for navigation. This radio "blackout" period has been a problem since the dawn of the manned space program and was an especially significant hindrance during the days of the Apollo missions. An appropriate mitigation method must allow for spacecraft to ground control and ground control to spacecraft communications through the reentry plasma sheath. Many mitigation techniques have been proposed, including but not limited to, aerodynamic shaping, magnetic windows, and liquid injection. The research performed on these mitigation techniques over the years will be reviewed and summarized, along with the advantages and obstacles that each technique will need to overcome to be practically implemented. A unique approach for mitigating the blackout communications problem is presented herein along with research results associated with this method. The novel method involves the injection of ceramic metal-oxide particulate into a simulated reentry plasma to quench the reentry plasma. Injection of the solid ceramic particulates is achieved by entrainment within induced, energetic cathode spot flows.

  1. 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

  2. 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.

  3. 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.

  4. 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.)

  5. 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.

  6. Blackouts: causes, impacts and measures that can avoid it; Blecautes: causas, impactos e medidas que podem evita-los

    Energy Technology Data Exchange (ETDEWEB)

    Lefevre, Marcos A.P.; Silveira, Jose Ricardo da

    1996-11-01

    This work traces a panorama of the blackouts in Brazil describing its causes and the several inconveniences that bring to society. It also presents the learnt lessons in function of the occurred events and the aspects that should be considered to increase the reliability of the power system 2 tabs.

  7. 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

  8. 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)

  9. 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.

  10. 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.

  11. 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.

  12. Severe accident analysis of a station blackout accident using MAAP-CANDU for the Point Lepreau station refurbishment project level 2 PSA

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M.J.; Petoukhov, S.M. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2012-07-01

    A Level 2 Probabilistic Safety Assessment was performed for the Point Lepreau Generating Station, using the MAAP-CANDU code to simulate the progression of severe core damage accidents and fission product releases. Five representative severe accidents were selected: Station Blackout, Small Loss-of-Coolant, Stagnation Feeder Break, Steam Generator Tube Rupture, and Shutdown State. Analysis results for the reference station blackout accident are discussed in this paper. (author)

  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. 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

    2016-01-06

    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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. SOARCA Peach Bottom Atomic Power Station Long-Term Station Blackout Uncertainty Analysis: Knowledge Advancement.

    Energy Technology Data Exchange (ETDEWEB)

    Gauntt, Randall O.; Mattie, Patrick D.; Bixler, Nathan E.; Ross, Kyle W.; Cardoni, Jeffrey N; Kalinich, Donald A.; Osborn, Douglas.; Sallaberry, Cedric Jean-Marie; Ghosh, S. Tina

    2014-02-01

    This paper describes the knowledge advancements from the uncertainty analysis for the State-of- the-Art Reactor Consequence Analyses (SOARCA) unmitigated long-term station blackout accident scenario at the Peach Bottom Atomic Power Station. This work assessed key MELCOR and MELCOR Accident Consequence Code System, Version 2 (MACCS2) modeling uncertainties in an integrated fashion to quantify the relative importance of each uncertain input on potential accident progression, radiological releases, and off-site consequences. This quantitative uncertainty analysis provides measures of the effects on consequences, of each of the selected uncertain parameters both individually and in interaction with other parameters. The results measure the model response (e.g., variance in the output) to uncertainty in the selected input. Investigation into the important uncertain parameters in turn yields insights into important phenomena for accident progression and off-site consequences. This uncertainty analysis confirmed the known importance of some parameters, such as failure rate of the Safety Relief Valve in accident progression modeling and the dry deposition velocity in off-site consequence modeling. The analysis also revealed some new insights, such as dependent effect of cesium chemical form for different accident progressions. (auth)

  20. 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

  1. 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

  2. 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...

  3. 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)

    Smith, Curtis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Prescott, Steven [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, Andrea [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cogliati, Joshua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kinoshita, Robert [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    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 impact of these factors on the safety of the plant, the Risk Informed Safety Margin Characterization (RISMC) project aims to provide insight to decision makers through a series of simulations of the plant dynamics for different initial conditions (e.g., probabilistic analysis and uncertainty quantification). This report focuses, in particular, on the application of a RISMC detailed demonstration case study for an emergent issue using the RAVEN and RELAP-7 tools. This case study looks at the impact of a couple of challenges to a hypothetical pressurized water reactor, including: (1) a power uprate, (2) a potential loss of off-site power followed by the possible loss of all diesel generators (i.e., a station black-out event), (3) and earthquake induces station-blackout, and (4) a potential earthquake induced tsunami flood. The analysis is performed by using a set of codes: a thermal-hydraulic code (RELAP-7), a flooding simulation tool (NEUTRINO) and a stochastic analysis tool (RAVEN) – these are currently under development at the Idaho National Laboratory.

  4. 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)

  5. Comparing Simulation Results with Traditional PRA Model on a Boiling Water Reactor Station Blackout Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Zhegang Ma; Diego Mandelli; Curtis Smith

    2011-07-01

    A previous study used RELAP and RAVEN to conduct a boiling water reactor station black-out (SBO) case study in a simulation based environment to show the capabilities of the risk-informed safety margin characterization methodology. This report compares the RELAP/RAVEN simulation results with traditional PRA model results. The RELAP/RAVEN simulation run results were reviewed for their input parameters and output results. The input parameters for each simulation run include various timing information such as diesel generator or offsite power recovery time, Safety Relief Valve stuck open time, High Pressure Core Injection or Reactor Core Isolation Cooling fail to run time, extended core cooling operation time, depressurization delay time, and firewater injection time. The output results include the maximum fuel clad temperature, the outcome, and the simulation end time. A traditional SBO PRA model in this report contains four event trees that are linked together with the transferring feature in SAPHIRE software. Unlike the usual Level 1 PRA quantification process in which only core damage sequences are quantified, this report quantifies all SBO sequences, whether they are core damage sequences or success (i.e., non core damage) sequences, in order to provide a full comparison with the simulation results. Three different approaches were used to solve event tree top events and quantify the SBO sequences: “W” process flag, default process flag without proper adjustment, and default process flag with adjustment to account for the success branch probabilities. Without post-processing, the first two approaches yield incorrect results with a total conditional probability greater than 1.0. The last approach accounts for the success branch probabilities and provides correct conditional sequence probabilities that are to be used for comparison. To better compare the results from the PRA model and the simulation runs, a simplified SBO event tree was developed with only four

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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)

  11. 印度大停电与继电保护的三大功能%India blackout and three functions of protective relay

    Institute of Scientific and Technical Information of China (English)

    董新洲; 曹润彬; 王宾; 施慎行; Dominik Bak

    2013-01-01

    On July 30 and 31, 2012, India experienced two electric power blackouts. These two blackouts were both triggered by tripping of zone-3 distance relay of the same transmission line due to overload, and caused unreasonable action of other relays which resulted in cascading trip and led to widespread power blackouts. India's blackouts have exposed the vulnerability of the existing power system, especially the defects of protective relay in case of overload and power swing. Based on the analysis of relay actions in the blackouts, this paper proposes three functions of protective relay to meet the security demand of modern power grid, which are system protection function for security of power system, preventive protection function and the function of rapid removal of fault equipment.%  简介了印度电网在2012年7月30日和7月31日发生的两起大停电事故。两起事故均起源于同一回输电线路距离保护 III 段因过负荷保护动作跳闸,并导致其他设备继电保护的不合理动作而引发连锁跳闸,造成大面积停电。印度大停电事故暴露了现有电力系统的脆弱性,尤其是继电保护在过负荷和系统振荡情况下的动作缺陷。基于对停电事故中继电保护行为的分析,提出了满足现代电网需求的继电保护三大功能:面向系统安全的系统保护功能、预防性保护功能和快速切除故障设备功能。

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. An Analysis of Station Blackout Sequences Using MELCOR1.8.5 Code for the Severe Accident Analysis DB

    Energy Technology Data Exchange (ETDEWEB)

    Song, Y. M.; Ahn, K. I. [KAERI, Daejeon (Korea, Republic of)

    2010-12-15

    The Korea Atomic Energy Research Institute (KAERI) has been constructing severe accident analysis database (DB) under a National Nuclear R and D Program. Especially, MAAP (commercial code being widely used for industries) DB for many scenarios including station blackout (SBO) has been completed up to now. This report shows the analysis results for SBO scenarios using MELCOR code. These results will be used for the degree of completion after being compared with MAAP results. The developing strategy of MELCOR code is the same with that of MAAP DB. For the generation of data set, the Korean standard nuclear power plant (KSNP) has been selected as a reference plant and the eight SBO scenarios are chosen to be analyzed based on the PSA results (these eight scenarios accounted for 99 percent of occurrence frequency of total 197 SBO scenarios). Both thermal hydraulics (T/H) and source term analysis have been performed using MELCOR version 1.8.5 for the chosen scenarios. But only major T/H variables treated in the MAAP report are listed among the generated data set, which shows the characteristics of each scenario. These SBO results together with those of the other initiating events (to be analyzed in the future) will be used as inputs for DB construction and special value will be found in the comparing and complimentary process with MAAP DB

  18. SOARCA Peach Bottom Atomic Power Station Long-Term Station Blackout Uncertainty Analysis: Convergence of the Uncertainty Results

    Energy Technology Data Exchange (ETDEWEB)

    Bixler, Nathan E.; Osborn, Douglas.; Sallaberry, Cedric Jean-Marie; Eckert-Gallup, Aubrey Celia; Mattie, Patrick D.; Ghosh, S. Tina

    2014-02-01

    This paper describes the convergence of MELCOR Accident Consequence Code System, Version 2 (MACCS2) probabilistic results of offsite consequences for the uncertainty analysis of the State-of-the-Art Reactor Consequence Analyses (SOARCA) unmitigated long-term station blackout scenario at the Peach Bottom Atomic Power Station. The consequence metrics evaluated are individual latent-cancer fatality (LCF) risk and individual early fatality risk. Consequence results are presented as conditional risk (i.e., assuming the accident occurs, risk per event) to individuals of the public as a result of the accident. In order to verify convergence for this uncertainty analysis, as recommended by the Nuclear Regulatory Commission’s Advisory Committee on Reactor Safeguards, a ‘high’ source term from the original population of Monte Carlo runs has been selected to be used for: (1) a study of the distribution of consequence results stemming solely from epistemic uncertainty in the MACCS2 parameters (i.e., separating the effect from the source term uncertainty), and (2) a comparison between Simple Random Sampling (SRS) and Latin Hypercube Sampling (LHS) in order to validate the original results obtained with LHS. Three replicates (each using a different random seed) of size 1,000 each using LHS and another set of three replicates of size 1,000 using SRS are analyzed. The results show that the LCF risk results are well converged with either LHS or SRS sampling. The early fatality risk results are less well converged at radial distances beyond 2 miles, and this is expected due to the sparse data (predominance of “zero” results).

  19. 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...

  20. 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...

  1. The 4 november 2006 blackout: an outage of 'technical' democracy?; Le delestage du 4 novembre 2006: une panne de la democratie technique?

    Energy Technology Data Exchange (ETDEWEB)

    Leteurtrois, J.P

    2007-08-15

    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. 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

  3. 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

  4. 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.

  5. 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)

  6. 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.

  7. 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.

  8. 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)

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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。

  14. Blackout Accdent Analyses of AC 600 Nuclear Power Plant%AC600核电厂新电事故分析

    Institute of Scientific and Technical Information of China (English)

    阎义洲; 臧希年

    2002-01-01

    In the advanced pressurized water reactor nuclear power plant design, the passive residual heat removal system is adopted. This system is composed of the secondary side of steam generator, air cooler and air loop which consists of the air cooling tower and atmosphere environment. Wall-air heat exchanging correlation equation is added to the RELAP5 Code. The modified code is used to simulate the AC600 PWR nuclear power plant transient behavior with Passive Residual Heat Removal System (PRHR) in micro-circulation start-up mode after the blackout accident occurs.The calculation results show that the higher the chimney or the larger the air cooler heat transfer area, the more the heat removal capacity of PRHR system. The computational results are consistent with the theoretical analyses.%我国改进型压水堆核电站设计中采用了非能动余热排出系统,它由蒸汽发生器及空气冷却器构成的汽水回路和空气回路组成.本文在RELAP5程序中补充了空气壁面换热结构关系式,分析改进型压水堆核电站(AC600)全厂断电事故后的瞬态行为.结果表明:烟囱高度增加、换热面积增加均使系统的排热能力增强;计算结果与理论分析结果相一致.

  15. 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.

  16. 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...

  17. 巴西"2·4"大停电事故及对电网安全稳定运行的启示%Blackout in Brazil Power Grid on February 4, 2011 and Inspirations for Stable Operation of Power Grid

    Institute of Scientific and Technical Information of China (English)

    林伟芳; 汤涌; 孙华东; 郭强; 赵红光; 曾兵

    2011-01-01

    On February 4, 2011, a wide spread electrical blackout occurred in Northeast Brazil power grid. The accident spread 8 states, and about 40 million people were involved. The pre-fault situation, cause, spread and restoration of the blackout are described. The lessons and experiences of the blackout are analyzed and summarized. Some recommendations for ensuring the security and stability of China's power grid and preventing the occurrence of blackout in China are presented.%2011年2月4日,巴西发生了大规模的停电事故.事故覆盖东北部8个州,影响人数约4 000万.文中介绍了事故前巴西电网的运行情况以及事故的起因、发展和恢复过程,分析总结了事故的经验和教训.结合中国电网,提出了保障电网安全稳定运行、防止大停电事故发生的建议.

  18. 从巴西电网"2·4"大停电事故看继电保护技术应用原则%Analyzing Principle of Protection Through the Blackout in Brazil Power Grid on February 4, 2011

    Institute of Scientific and Technical Information of China (English)

    刘宇; 舒治淮; 程逍; 张胜祥

    2011-01-01

    简单介绍了2011年2月4日巴西东北部地区发生的大停电事故.事故由Luiz Gonzaga变电站内保护装置元件故障导致开关失灵保护误动引起.对照本次事故,分析了巴西电网采用的失灵保护逻辑方案的不足,并对中国电网的开关失灵保护标准化方案作了详细的分析.分析结果表明,中国电网开关失灵保护标准化方案能可靠避免该类型事故的发生.%On February 4, 2011, a blackout occurred in Northeast of Brazil. The process of blackout is introduced and analyzed. An error of an electronic component in the relay equipment aroused the false action of the breaker failure protection in the substation Luiz Gonzaga and resulted in the blackout finally. With reference to the blackout incident in Brazil, the deficiency of the breaker failure logic adopted in Brazil power grid is analyzed, and the standard breaker failure logic developed by State Grid Corporation of China is also analyzed. The analysis results reveal that the standard logic can avoid the occurring of similar incidents.

  19. 基于射线追踪理论的超视距通信盲区分布研究%Distribution of OTH Communications Blackout on the Theory of Ray Tracing

    Institute of Scientific and Technical Information of China (English)

    高超; 周朋

    2016-01-01

    In the process of shipboard OTH communication atmospheric ducting environment,the existence communications electromagnetic blackout can cause communication interruption of signals,and the target within the blackout cannot receive signals.We researched electromagnetic wave propagation characteristics in the ducting environment that make the use of ray tracing theory,simulated and analyzed the effects of the varies different parameters of communications systems to electromagnetic blind distribution.According to the simulation results,the electromagnetic blind on top of the atmosphere ducting that has more serious effects is the change of the height of the transmitting antenna and transmitter elevation,and the decrease of transmitter elevation has greater impact on hopping blind of the first jump point.%针对大气波导环境下舰载超视距通信过程中通信电磁盲区的存在会造成通信信号的中断,使处于盲区内的目标无法接收信号的问题。利用射线追踪理论研究电磁波在波导环境下的传播特征,仿真分析了通信系统不同发射参数变化对电磁盲区分布的影响。仿真结果表明:对大气波导顶端通信电磁盲区影响较大的是发射天线高度和发射仰角的变化,而减小发射仰角对第一个跳跃点的跳跃盲区影响较大。

  20. 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.

  1. 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。

  2. 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.

  3. 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.

  4. Summary and revelation of "2009· 11· 10" and "2011 · 2· 4" blackouts in Brazil Power System%巴西“2009-11-10”和“2011-2-4”大停电事故及启示

    Institute of Scientific and Technical Information of China (English)

    邹江峰; 章显亮

    2011-01-01

    Based on the survey report of ONS (National Power System Operator) in Brazil, "2009·11·10" Wand "2011·2·4"blackout are described. The pre-fault condition, fault causes, spread and restoration process are analyzed. According to the summary of lessons and experience learned from these blackouts, recommendations are presented to improve security operation of power system in China.%查阅了巴西电网运行部门对巴西“2009·11·10”和“2011·2·4”大停电事故调查报告,简要描述了这2次停电的事故过程,重点回顾了具有典型特征的“2009·11·10”巴西大停电的事故经过,通过对事故的发生、发展和恢复过程的描述及事故原因的分析,借鉴国外停电事故的经验教训,结合我国电网的实际情况,总结了对我国电网安全运行的启示.

  5. 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。

  6. 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)

  7. 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.

  8. 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.

  9. 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。

  10. 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.

  11. 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。

  12. 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。

  13. Source Term Analysis in Severe Accident Induced by Large Break Loss of Coolant Accident Coincident With Ship Blackout for Ship Reactor%船用堆大破口失水叠加全船断电严重事故源项分析

    Institute of Scientific and Technical Information of China (English)

    张彦招; 张帆; 赵新文; 郑映峰

    2013-01-01

    以某船用压水堆为研究对象,采用M ELCOR程序建立事故分析模型,研究大破口失水事故叠加全船断电严重事故下放射性裂变产物的行为,着重分析了惰性气体和CsI的释放、迁移、滞留特点及在堆舱内的分布。结果表明,83.12%惰性气体从堆芯释放出来,并主要存在于堆舱的气空间;83.08%的CsI从堆芯释放出来,其中,72.66%滞留在堆坑熔融物与一回路内,27.34%释放到堆舱内,并主要溶解于舱底水池中。本文分析结果可为舱室剂量评估、核应急管理提供依据。%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 . T he 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 w hich 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 .

  14. 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.

  15. 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.

  16. 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...

  17. 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 ...

  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. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Beisiegel, A.; Foppe, F.; Wich, M.

    2014-07-01

    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)

  1. Anatomy of power system blackouts and preventive strategies by rational supervision and control of protection systems

    Energy Technology Data Exchange (ETDEWEB)

    Phadke, A.G. [Virginia Polytechnic Institute and State Univ., Blacksburg, VA (United States); Horowitz, S.H.; Thorp, J.S.

    1995-01-01

    This report establishes the concept of hidden failures in relays and associated devices used for the protection of electric power systems. A hidden failure is a defect such as a component failure, inappropriate setting or incorrect external connection that remains undetected until some other system event causes the hidden failure to initiate a cascading outage. Associated with the study of hidden failures, this report examines the impact such defects might have by defining regions of vulnerability. A region of vulnerability is the area of the system in which a hidden failure will be activated. To determine such areas we have established criteria associated with load flows and steady-state stability, such as lack of convergence, and employed a technique known as importance sampling in which the simulation is done with the probabilities altered so that the rare event happens more frequently. Our purpose is to provide a framework for further research into relay vulnerability, possibly using adaptive techniques to eliminate hidden defects. We believe control strategies can be developed to prevent cascading normal operations from developing into severe outages by extending the present criteria using steady-state stability and load flow studies into the area of transient stability, and further research into importance sampling would provide significant benefits in evaluating corrective actions.

  2. 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

  3. 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.

  4. Blackouts to Lifelong Memories: Digital Storytelling and the College Alcohol Habitus

    Science.gov (United States)

    Burnett, Audrey J.; Walter, Katherine Ott; Baller, Stephanie L.

    2016-01-01

    Digital stories (N = 71) were created in partial fulfillment of undergraduate coursework at a large mid-Atlantic university. Based on the alcohol habitus, two major themes emerged: the content present (e.g., dissonance between visual and narrative representations) and the content conspicuously absent from the stories (e.g., first-person…

  5. 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,...

  6. 17 CFR 245.101 - Prohibition of insider trading during pension fund blackout periods.

    Science.gov (United States)

    2010-04-01

    ... equity securities in connection with a merger, acquisition, divestiture or similar transaction occurring... from section 306(a)(1) of the Sarbanes-Oxley Act of 2002: (1) Any acquisition of equity securities... acquisition is made pursuant to a plan providing for the regular reinvestment of dividends or interest and...

  7. 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.

  8. Optimal blackouts: empirical results on reducing the social cost of electricity outages through efficient regional rationing

    NARCIS (Netherlands)

    M. de Nooij; R. Lieshout; C. Koopmans

    2009-01-01

    The demand and supply of electricity must always balance. If supply falls short of demand, then price increases or voluntary demand reductions might help to maintain the balance in the system. Should these prove insufficient, then rationing is necessary. Rationing means interrupting the electricity

  9. 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.

  10. 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.

  11. Power blackouts, sudden death, and flash crashes: The physics of interdependent networks

    Science.gov (United States)

    Stanley, H. Eugene

    2014-03-01

    Recent disasters ranging from abrupt financial ``flash crashes'' and large-scale power outages to sudden death among the elderly dramatically exemplify the fact that the most dangerous vulnerability is hiding in the many interdependencies among different networks. This talk reports recent work quantifying failure mechanisms in interconnected networks, and demonstrates the need to consider mutually dependent network properties in designing resilient systems. Specifically, we have uncovered new laws governing the nature of switching phenomena in coupled networks, and found that phenomena that are continuous ``second order'' phase transitions in isolated networks become discontinuous abrupt ``first order'' transitions in interdependent networks [J. Gao, S. V. Buldyrev, H. E. Stanley, and S. Havlin, ``Novel Behavior of Networks Formed from Interdependent Networks,'' Nature Physics 8, 40 (2012)]. We also report parallel efforts to understand the phenomenon of spontaneous recovery in dynamical networks as occurs, e.g., immediately after a flash crash [A. Majdandzic, B. Podobnik, S. V. Buldyrev, D. Y. Kenett, S. Havlin, and H. E. Stanley, ``Spontaneous Recovery in Dynamic Networks,'' Nature Physics 9, No. 1 (2014)].

  12. 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...

  13. 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。...

  14. 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。...

  15. 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.

  16. 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.

  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. 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.

  19. 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

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  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...

  9. 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....

  10. 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.

  11. Clinical Study of Cardiac Sudden Blackouts Cardioversion Caused by Acute Myocardial Infarction%急性心肌梗死致心脏骤停电复律临床研究

    Institute of Scientific and Technical Information of China (English)

    张敏

    2014-01-01

    Objective To study the basic hospital caused by cardiac ar est, acute myocardial infarction (SCA) first aid measures. Methods The clinical data were retrospectively analyzed by recovery in the heart and lung of acute myocardial infarction in 19 cases of cardiac ar est caused by the. Results 19 cases with immediate defibril ation restoration of sinus rhythm, 17cases were cured, 1 cases improved, the total ef ective rate was 89%.Conclusion Immediate electric defibril ation in treatment of acute myocardial infarction and sudden cardiac ar est caused is the most crucial step.%目的研究因心脏骤停引起的急性心肌梗死的的急救措施。方法通过对19例急性心肌梗死引起的心脏骤停进行心肺复苏的临床资料回顾性分析。结果19例立即除颤,17例窦性心律恢复,总有效率达89%。结论立即实施电除颤在急性心肌梗死后心脏骤停的抢救中是最关键的一步。

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 巴西"11·10"大停电事故分析及启示%Analysis and Lessons of the Blackout in Brazil Power Grid on November 10, 2009

    Institute of Scientific and Technical Information of China (English)

    林伟芳; 孙华东; 汤涌; 卜广全; 印永华

    2010-01-01

    2009年11月10日,巴西发生了大规模停电事故.结合巴西国家电力系统运行局的官方调查报告,详细介绍事故前巴西电网的运行情况、事故的起因、发展和恢复过程,分析总结事故的教训和经验,并结合中国电网实际,提出保障中国电网安全稳定运行、防止大停电事故发生的建议.

  4. 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. ...

  5. 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.

  6. 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...

  7. 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,...

  8. 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.

  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. 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"

  14. 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 ...

  15. 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 §...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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)....

  2. 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...

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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 thi......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...... combined with widely dispersed trading locations may be a viable means of protection against market failure during massive power disruptions or terrorist attacks....

  12. 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 thi......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...... combined with widely dispersed trading locations may be a viable means of protection against market failure during massive power disruptions or terrorist attacks....

  13. 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

  14. 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...

  15. 77 FR 33811 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2012-06-07

    ... a deviation of voltage or frequency of 5 percent or more below standard voltage or frequency. During... to a potential electrical blackout, such as unusually low frequency, equipment overload, capacity or... emergency engines to only operate during true emergencies or when voltage or frequency varies...

  16. 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.

  17. 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

  18. 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…

  19. Technical and economical optimization of the reliability of electric power distribution planning; Otimizacao tecnico-economica da confiabilidade no planejamento da distribuicao eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Arango, Hector [Escola Federal de Engenharia de Itajuba, MG (Brazil); Arango, Hector G. [Faculdade de Ciencias Economicas do Sul de Minas, MG (Brazil)

    1988-12-31

    The optimization of reliability represents the best compromise between the benefits caused to the overall economic system (including producers and consumers) arriving from the reducing of blackouts (both in number and duration), and the investments demanded for such reducing process. In this work some issues related to the reliability index, R, are presented and discussed 3 refs., 2 figs.

  20. 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.

  1. 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.

  2. Economic feasibility of maximising daylighting of a standard office building with efficient electric lighting

    DEFF Research Database (Denmark)

    Fontoynont, Marc; Ramananarivo, Karine; Soreze, Thierry Silvio Claude;

    2016-01-01

    costs and is typical of the French market. We have compared scenarios that entail moving service spaces to the periphery, increasing ceiling height and adding light wells of various shapes. These special features increased the proportion of the indoor area with sufficient daylight by up to 40......' well-being, safety in case of an electrical black-out, and rental and resell value....

  3. 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. (...)

  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. 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…

  6. 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.

  7. 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

  8. 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...

  9. 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...

  10. 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...

  11. 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),...

  12. "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

  13. 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...

  14. 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...

  15. 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

  16. 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)...

  17. 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,...

  18. 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...

  19. 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

  20. 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...

  1. 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...

  2. 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

  3. 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.

  4. Control and Protection Cooperation Strategy for Voltage Instability

    DEFF Research Database (Denmark)

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

    2012-01-01

    Most cascaded blackouts are caused by unexpected backup relay operations due to low voltage or overload state caused by post fault load restoration dynamics. If such state can be sensed and adjusted appropriately prior to those relay actions, system stability might be sustained. This paper propos...

  5. Coordinated Agent-Based Control for On-line Voltage Instability Prevention

    NARCIS (Netherlands)

    Baalbergen, J.F.

    2013-01-01

    Service interruptions have a significant impact on society and therefore the main objective of power system planning and operation is to ensure that they do not happen. Because voltage instability is one of the dynamic phenomena that may result in a system-wide blackout, this type of stability probl

  6. 75 FR 73947 - Securities of Nonmember Insured Banks

    Science.gov (United States)

    2010-11-30

    ... bonuses and profits), 306 (insider trades during blackout periods), 401(b) (disclosure of pro forma... for annual, quarterly, current, and other reports of issuers), Sec. 335.321 (Maintenance of records... (Statement of changes in beneficial ownership of securities), Sec. 335.613 (Annual statement of...

  7. Resource Efficient Scheduling, Optimization and Control.

    NARCIS (Netherlands)

    van den Akker, Marjan; Derksen, Christian; Kowalczyk, Ryszard; Mönch, Lars; Valogianni, Konstantina; van Heck, Erik; Zhang, Minjie

    2014-01-01

    This report documents the program and the outcomes of Dagstuhl Seminar 14181 "Multi-agent systems and their role in future energy grids". A number of recent events (e.g. Fukushima, Japan, and the largest blackout in history, India) have once again increased global attention on climate change and res

  8. A topological investigation of phase transitions of cascading failures in power grids

    NARCIS (Netherlands)

    Koç, Y.; Warnier, M.; Mieghem, P. van; Kooij, R.E.; Brazier, F.M.T.

    2014-01-01

    Cascading failures are one of the main reasons for blackouts in electric power transmission grids. The economic cost of such failures is in the order of tens of billion dollars annually. The loading level of power system is a key aspect to determine the amount of the damage caused by cascading failu

  9. 77 FR 16483 - Petition for Rulemaking Submitted by the Natural Resources Defense Council, Inc.

    Science.gov (United States)

    2012-03-21

    ...; ] NUCLEAR REGULATORY COMMISSION 10 CFR Part 50 Petition for Rulemaking Submitted by the Natural Resources... Natural Resources Defense Council, Inc. (NRDC or the petitioner), in the rulemaking process. The... establish station blackout (SBO) mitigation strategies and resources. The NRC determined that the...

  10. 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).

  11. 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?.

  12. 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

  13. The Impact of the Topology on Cascading Failures in a Power Grid Model

    NARCIS (Netherlands)

    Koç, Y.; Warnier, M.; Van Mieghem, P.; Kooij, R.E.; Brazier, F.M.T.

    2014-01-01

    Cascading failures are one of the main reasons for large scale blackouts in power transmission grids. Secure electrical power supply requires, together with careful operation, a robust design of the electrical power grid topology. Currently, the impact of the topology on grid robustness is mainly as

  14. 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.

  15. A True Lifeline

    Institute of Scientific and Technical Information of China (English)

    LAN XINZHEN

    2010-01-01

    @@ Chenzhou,a medium-sized city in Hunan Province,knows what it's like to be cut off from the rest of the world.The city suffered a 15-day blackout during a snowstorm in 2008 in south China when power supply was disrupted and many trains were delayed.

  16. Optimalisering Ventilationjet systeem

    NARCIS (Netherlands)

    Weel, van P.A.

    2015-01-01

    The Ventilationjet system is used to dehumidify a greenhouse with a fully closed blackout screen during the night. Gerbera producer Zuijderwijk and Witzier in the Netherlands uses this equipment but was not satisified with the duhumidification capacity since the RH was rising to unwanted levels. Tha

  17. 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....

  18. 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...

  19. 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...

  20. 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....

  1. 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)

  2. 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.

  3. 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.

  4. Brazil Lightning Bolts Set Shocking World Record

    Institute of Scientific and Technical Information of China (English)

    卞小翩

    2002-01-01

    巴西是世界上最大的地处热带地区的国家,因此,它就成了世界“雷电之国”。让我们吃惊的是,10%of all lightning-rylated deaths in the world竟然发生在巴西!文章出现一个名词词组 power blackouts,而擅长使用词汇connotation的英语也常常“活用”此词。 He had had a blackout after the accident./事故发生后,他晕过去一阵子。

  5. 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...

  6. 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...

  7. 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...

  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. 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...

  10. 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.

  11. 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.

  12. 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.

  13. 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...

  14. 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...

  15. 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 ...

  16. 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...

  17. 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...

  18. 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 ...

  19. 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...

  20. 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...

  1. 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) ...

  2. 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...

  3. 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...

  4. More regulation is necessary; Mere regulering er noedvendig

    Energy Technology Data Exchange (ETDEWEB)

    Trong, Maj Dang

    2004-07-01

    The EU Commission has submitted a proposal to increase the power supply security in the member countries. This proposal includes a package of initiatives intended to speed up investment in the power transmission connections between the EU countries. But increased transmission capacity alone cannot guarantee the supply and prevent serious blackouts like those occurring in 2003. The Commission also presents a controversial proposal to instruct the member countries to reduce energy consumption by 1 per cent per year.

  5. Energy solutions for sustainable development. Proceedings

    DEFF Research Database (Denmark)

    production technologies such as fuel cells, hydrogen, bio-energy and wind energy • Centralized energy technologies such as clean coal technologies • Providing renewable energy for the transport sector • Systems aspects, differences between the various major regions throughout the world • End-use technologies......, efficiency improvements and supply links • Security of supply with regard to resources, conflicts, black-outs, natural disasters and terrorism...

  6. MELCOR DB Construction for the Severe Accident Analysis DB

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-15

    The Korea Atomic Energy Research Institute (KAERI) has been constructing a severe accident analysis database (DB) under a National Nuclear R and D Program. In particular, an MAAP (commercial code being widely used in industries for integrated severe accident analysis) DB for many scenarios including a station blackout (SBO) has been completed. This paper shows the MELCOR DB construction process with examples of SBO scenarios, and the results will be used for a comparison with the MAAP DB

  7. 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)

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 基于层次分析法和熵权法的电网风险评估%Risk Assessment of Power Networks Based on AHP and Entropy Weight Method

    Institute of Scientific and Technical Information of China (English)

    刘宇彬; 刘建华

    2013-01-01

    Some indicators of large-scale electric power networks have significant impact on the large-scale black-outs and chain collapse of a power system. In order to find the lines that will have a huge impact on the whole net-work after a fault switching-off, and prevent large-scale blackouts, this paper proposes and establishes an objective and rational safety evaluation system for distribution networks, in which the analytic hierarchy process ( AHP) and entropy weight method are used to conduct an objectively and subjectively risk assessment of a distribution network, quantify vulnerable lines from a quantitative point of view, and provide information for decision making to prevent cascading trips and large-scale blackouts. The proposed method is verified in IEEE39 node system.%大规模电力网络中,某些指标对电力系统大规模停电和连锁崩溃的发生有着重要的影响。为了寻找因故障开断后将会对全网造成巨大影响的线路,从而达到预防大规模停电的效果,建立了一套客观合理的配电网安全性评估体系,并运用层次分析法和熵权法相综合的主客观并重的评价方法对配电网进行风险评估,从定量的角度量化出较为脆弱的线路,为预防连锁跳闸和大规模停电提供决策信息。在IEEE39节点系统上对此方法予以验证。

  18. 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

  19. 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)

  20. Combating False Reports for Secure Networked Control in Smart Grid via Trustiness Evaluation

    CERN Document Server

    Li, Husheng; Djouadi, Seddik M

    2010-01-01

    Smart grid, equipped with modern communication infrastructures, is subject to possible cyber attacks. Particularly, false report attacks which replace the sensor reports with fraud ones may cause the instability of the whole power grid or even result in a large area blackout. In this paper, a trustiness system is introduced to the controller, who computes the trustiness of different sensors by comparing its prediction, obtained from Kalman filtering, on the system state with the reports from sensor. The trustiness mechanism is discussed and analyzed for the Linear Quadratic Regulation (LQR) controller. Numerical simulations show that the trustiness system can effectively combat the cyber attacks to smart grid.

  1. Havana: A Bike-Friendly City?

    Science.gov (United States)

    Coyula, Miguel

    2016-07-01

    The abrupt breakup of the USSR and socialist bloc in the early 1990s dealt a devastating blow to the island's economy. Almost overnight, beneficial aid and trade provided by the Council for Mutual Economic Assistance ground to a halt, including 80% of foreign trade previously conducted as barter and sales of 13 million tons of oil per year at preferential prices. When the Cuban economy bottomed out in 1993, oil imports had dropped from 13 to 4 million tons annually. At the time, Cuba depended almost entirely on imported oil and the dramatic decline in imports created massive blackouts, leaving most Cuban homes without electricity 12 hours a day. PMID:27510938

  2. 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

  3. Transient analysis in the CAREM 25 nuclear power plant; Estudio de transitorios en la Central Nuclear CAREM 25

    Energy Technology Data Exchange (ETDEWEB)

    Abbate, Pablo M. [Investigacion Aplicada SE (INVAP), San Carlos de Bariloche (Argentina)

    1995-12-31

    Some of the transient analysis performed to evaluate the behaviour of CAREM (25 MW{sub e}) NPP are shown. The CAREM is a project for an integrated, auto pressurized and natural circulation NPP. Using RETRAN-02 a model has been set, it comprises the primary system and part of the secondary system, as well as the main control loops. Results are shown regarding the excellent characteristics of the reactor to accommodate perturbations originated in the secondary system, such as blackout and loss of the heat sink. (author). 5 refs, 7 figs, 2 tabs.

  4. 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

  5. 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.)

  6. 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....

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

    Science.gov (United States)

    Gillman, Eric D.; Amatucci, W. E.

    2014-06-01

    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.

  8. 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

  9. 区域互联电网故障解列方法综述%Comments and Overviews on the Islanding Methods of Large Interconnected Power Grid

    Institute of Scientific and Technical Information of China (English)

    胥威汀; 戴松灵; 张全明; 杜新伟; 任志超

    2015-01-01

    Grid islanding is the last defense of the security and stability of power grid. It can inhibit the spreading of serious disturbance in power system, such as oscillatory and instability between asynchronous generator groups, and create self-balancing environment for every isolated island. The successful grid islanding control can save many power loads, and avoid large-scale blackout, such as the blackout of USA and Canada in 2003, the Brazil blackout in 2009 and the India blackout in 2012. So the grid islanding control would contribute to reduce the losses of national economy, and maintain the social stability and safety. On the contrary, an unsuccessful grid islanding control would suffer the power system and the society. In the paper, the development of the grid islanding control had been overviewed from the aspects of engineering application and theoretical research. The theoretical research of grid islanding control and its problems were summarized, including the splitting surface definition methods and splitting timing judgment methods. Suggestions for these issues were proposed in the paper.%解列控制是电力系统安全稳定控制的最后一道防线,其作用在于阻断严重扰动在电网中的恶性蔓延,如异步机群振荡失稳,并为解开后的孤网创造一个自平衡的运行环境.成功的解列能够挽救大量的电力负荷,避免发生如2003年美加大停电、2009年巴西大停电和2012年印度大停电等类似的大范围事故,减轻国民经济损失,维持社会稳定安全;而不成功的解列则会导致系统遭受更大的冲击.该文从工程应用和理论研究两个层面对电网解列现状进行了综述,总结出当前解列控制及其理论研究中尚存的问题,包括解列面界定方法、解列时机判断等问题,并针对这些问题提出相应建议.

  10. 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.

  11. 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...

  12. 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...

  13. 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.

  14. 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...

  15. 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...

  16. 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...

  17. 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

  18. 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

  19. 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...

  20. 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.

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Petoukhov, S.M.; Brown, M.J.; Mathew, P.M. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2012-07-01

    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)

  3. Vision for a self-healing power grid

    Energy Technology Data Exchange (ETDEWEB)

    Moslehi, Khosrow; Kumar, Ranjit

    2007-07-01

    Power system reliability has been thrust into the limelight by recent blackouts around the world. The social and economic costs of these failures can add up to billions of dollars every year. As the digital age prevails, more efficient manufacturing processes, based on computers and power electronics, have come to dominate industry. As the portion of electricity in the total energy consumption continues to grow, the value of power system reliability increases. This article discusses a vision for state-of-the-art solutions to improve power system reliability through improved monitoring and control. (auth)

  4. 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.

  5. 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)

  6. 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)

  7. 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.

  8. 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.)

  9. 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)

  10. A study of cascading failures in real and synthetic power grid topologies using DC power flows

    CERN Document Server

    Spiewak, Russell; Forman, Yakir; Soltan, Saleh; Zussman, Gil

    2016-01-01

    Using the linearized DC power flow model, we study cascading failures and their spatial and temporal properties in the US Western Interconnect (USWI) power grid. We also introduce the preferential Degree And Distance Attachment (DADA) model, with similar degree distributions, resistances, and currents to the USWI. We investigate the behavior of both grids resulting from the failure of a single line. We find that the DADA model and the USWI model react very similarly to that failure, and that their blackout characteristics resemble each other. In many cases, the failure of a single line can cause cascading failures, which impact the entire grid. We characterize the resilience of the grid by three parameters, the most important of which is tolerance ${\\alpha}$, which is the ratio of the maximal load a line can carry to its initial load. We characterize a blackout by its yield, which we define as the ratio of the final to the initial consumed currents. We find that if ${\\alpha}\\leq2$, the probability of a large ...

  11. 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.

  12. 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)

  13. 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

  14. 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

  15. 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.

  16. 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

  17. An analysis on the severe accident progression with operator recovery actions

    Energy Technology Data Exchange (ETDEWEB)

    Vo, T.H. [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejon 305-353 (Korea, Republic of); Korea University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Song, J.H., E-mail: dosa@kaeri.re.kr [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejon 305-353 (Korea, Republic of); Korea University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Kim, T.W.; Kim, D.H. [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejon 305-353 (Korea, Republic of)

    2014-12-15

    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.

  18. 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.

  19. 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

  20. CFD Analysis of a Hybrid Heat Pipe for In-Core Passive Decay Heat Removal System

    Energy Technology Data Exchange (ETDEWEB)

    Jeong Yeong Shin; Kim, Kyung Mo; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-05-15

    Station blackout (SBO) accident is the event that all AC power is totally lost from the failure of offsite and onsite power sources. Although electricity was provided from installed batteries for active system after shutdown, they were failed due to flooding after tsunami. The vulnerability of the current operating power plant's cooling ability during extended station blackout events is demonstrated and the importance of passive system becomes emphasized. Numerous researches about passive system have been studied for proper cooling residual heat after Fukushima nuclear power plant accident. Heat pipe is the effective passive heat transfer device that latent heat of vaporization is used to transport heat over long distance with even small temperature difference. Since liquid flows due to capillary force from wick structure and steam flows up due to buoyancy force, power is not necessary. Heat pipe is widely used in removal of local hot spot heat fluxes in CPU and thermal management in space crafts and satellites. Hybrid control rod, which consists of heat pipe with B{sub 4}C for wick structure material can be used for removing residual heat after. It can be applied to both for shutdown and cooling of decay heat in reactor. This concept is independent of external reactor situation like operator's mistake or malfunction of active cooling system. Heat pipe cooling system can be applied to Emergency Core Cooling System, In-Vessel Retention, containment and spent fuel cooling, contributing to decrease Core Damage Frequency.

  1. 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。

  2. Design Discussion of the Double-bus and Subsection Breaker Electrical Connection Applied in 220 kV Substation GIS%220kV变电站GIS配电装置双母线刀闸分段设计探讨

    Institute of Scientific and Technical Information of China (English)

    王文莉; 李颖瑾; 马悦

    2011-01-01

    近年来,220kV变电站中高压配电装置采用GIS设备越来越普遍,根据变电站的规模,220kV、110kVGIS接线型式为双母线时,扩建时变电站全部停电的缺点逐渐暴露。通过实例技术经济比较,提出220kV变电站GIS双母线接线优化为双母线刀闸分段接线的优化方案。该方案的提出.有效地避免了目前变电站扩建时需全站停电的问题。%In recent years, Gas Insulated Metal-enclosed Switchgear are applied more popularly at the 220 kV substation. However, the 220 kV substation site-wide blackout will happen during the period of the substation extension and reconstruction, with the double-bus electrical connection applied. Depending on the practical project and based on the technical-economical comparison, the optimized design scheme with the double-bus and Subsection breaker electrical connection applied, is proposed. With this scheme, the substation site-wide blackout can be avoided.

  3. 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

  4. 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.

  5. 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.

  6. Investigation of incident scenarios for BWR-type plant, taking into consideration the effects of the plant emergency protection systems. The Kruemmel reactor station (KKK) as an example. [accident management]. Untersuchungen zu Ereignisablaeufen fuer SWR-Anlagen unter Einbeziehung von Massnahmen des anlageninternen Notfallschutzes am Beispiel des Kernkraftwerkes Kruemmel (KKK)

    Energy Technology Data Exchange (ETDEWEB)

    Erven, U.; Nolte, W.; Linden, J. v.; Weidlich, H.

    1988-01-01

    The hypothetical scenarios discussed are the following: (1) Failure of the main heat sink with simultaneous breakdown of after-heat removal from the condensation chamber. (2) Failure of the entire, not battery-supported a.c. supply system (station blackout). (3) Loss of coolant in the containment, with failure of the sump pumping system. The study in addition to the initial failure assumes failure of further systems (condensation chamber cooling, non-battery-supported standby power supply, containment sump pumping system). In all three cases, further emergency provisions are possible in order to prevent dry-out of the reactor core, or undue pressure buildup in the containment. These provisions are easily feasible, as analyses have shown that there is sufficient time for carrying out the planned emergency protection measures or the plant protection measures, namely: 27 hours in case of 'failure of main heat sink', at least 5 hours in case of 'station blackout', and at least 4 days in case of 'loss of coolant in the containment'. The frequencies of occurrence of inadmissible plant conditions are low that there is consensus on the national and international level that such cases are not relevant for risk assessment, and therefore cannot be taken into consideration for technical protection measures development.

  7. [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

  8. 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

  9. 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

  10. The personal and health service impact of falls in 85 year olds: cross-sectional findings from the Newcastle 85+ cohort study.

    Directory of Open Access Journals (Sweden)

    Joanna Collerton

    Full Text Available INTRODUCTION: Falls are common in older people and increase in prevalence with advancing old age. There is limited knowledge about their impact in those aged 85 years and older, the fastest growing age group of the population. We investigated the prevalence and impact of falls, and the overlap between falls, dizziness and blackouts, in a population-based sample of 85 year olds. METHODS: DESIGN: Cross-sectional analysis of baseline data from Newcastle 85+ Cohort Study. SETTING: Primary care, North-East England. PARTICIPANTS: 816 men and women aged 85 years. MEASUREMENTS: Structured interview with research nurse. Cost-consequence analysis of fall-related healthcare costs. RESULTS: Over 38% (313/816 of participants had fallen at least once in the previous 12 months and of these: 10.6% (33/312 sustained a fracture, 30.1% (94/312 attended an emergency department, and 12.8% (40/312 were admitted to hospital. Only 37.2% (115/309 of fallers had specifically discussed their falls problem with their general practitioner and only 12.7% (39/308 had seen a falls specialist. The average annual healthcare cost per faller was estimated at £202 (inter-quartile range £174-£231 or US$329 ($284-$377. 'Worry about falling' was experienced by 42.0% (128/305 of fallers, 'loss of confidence' by 40.0% (122/305, and 'going out less often' by 25.9% (79/305; each was significantly more common in women, odds ratios (95% confidence interval for women: men of 2.63 (1.45-4.55, 4.00 (2.27-7.14, and 2.86 (1.54-5.56 respectively. Dizziness and blackouts were reported by 40.0% (318/796 and 6.4% (52/808 of participants respectively. There was marked overlap in the report of falls, dizziness and blackouts. CONCLUSIONS: Falls in 85 year olds are very common, associated with considerable psychological and physical morbidity, and have high impact on healthcare services. Wider use of fall prevention services is needed. Significant expansion in acute and preventative services is

  11. Effectiveness of containment sprays in containment management

    International Nuclear Information System (INIS)

    A limited study has been performed assessing the effectiveness of containment sprays-to mitigate particular challenges which may occur during a severe accident. Certain aspects of three specific topics related to using sprays under severe accident conditions were investigated. The first was the effectiveness of sprays connected to an alternate water supple and pumping source because the actual containment spray pumps are inoperable. This situation could occur during a station blackout. The second topic concerned the adverse as well as beneficial effects of using containment sprays during severe accident scenario where the containment atmosphere contains substantial quantities of hydrogen along with steam. The third topic was the feasibility of using containment sprays to moderate the consequences of DCH

  12. A neural networks based ``trip`` analysis system for PWR-type reactors; Um sistema de analise de ``trip`` em reatores PWR usando redes neuronais

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Antonio Carlos Pinto Dias

    1993-12-31

    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) 11 refs., 39 figs.

  13. 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)

  14. 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)

  15. Intelligent decision support algorithm for distribution system restoration.

    Science.gov (United States)

    Singh, Reetu; Mehfuz, Shabana; Kumar, Parmod

    2016-01-01

    Distribution system is the means of revenue for electric utility. It needs to be restored at the earliest if any feeder or complete system is tripped out due to fault or any other cause. Further, uncertainty of the loads, result in variations in the distribution network's parameters. Thus, an intelligent algorithm incorporating hybrid fuzzy-grey relation, which can take into account the uncertainties and compare the sequences is discussed to analyse and restore the distribution system. The simulation studies are carried out to show the utility of the method by ranking the restoration plans for a typical distribution system. This algorithm also meets the smart grid requirements in terms of an automated restoration plan for the partial/full blackout of network.

  16. 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.

  17. 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.

  18. Willingness to pay for public services and quality of supply in the electricity area; Zahlungsbereitschaft fuer Service public und Versorgungsqualitaet im Strombereich

    Energy Technology Data Exchange (ETDEWEB)

    Leukert, K.; Telser, H.; Vaterlaus, S.; Mahler, P.

    2008-07-01

    This report for the Swiss Federal Office of Energy (SFOE) takes a look at the results of a study made on the willingness to pay for public services and quality of supply in the electricity area. First, the starting point of the study and definitions of quality of supply and security of supply are noted. The methods used in the study are presented and macro-economic aspects are reviewed. The costs of black-outs are examined and the carrying out of surveys in the electricity market is discussed. The results of surveys made in households and commercial enterprises concerning the willingness to pay for security of supply and the costs incurred when supplies fail are presented and discussed. The report is completed with a comprehensive list of references and an appendix containing the results of the various tests and surveys made.

  19. Effect of Wind Intermittency on the Electric Grid: Mitigating the Risk of Energy Deficits

    CERN Document Server

    George, Sam O; Nguyen, Scott V

    2010-01-01

    Successful implementation of California's Renewable Portfolio Standard (RPS) mandating 33 percent renewable energy generation by 2020 requires inclusion of a robust strategy to mitigate increased risk of energy deficits (blackouts) due to short time-scale (sub 1 hour) intermittencies in renewable energy sources. Of these RPS sources, wind energy has the fastest growth rate--over 25% year-over-year. If these growth trends continue, wind energy could make up 15 percent of California's energy portfolio by 2016 (wRPS15). However, the hour-to-hour variations in wind energy (speed) will create large hourly energy deficits that require installation of other, more predictable, compensation generation capacity and infrastructure. Compensating for the energy deficits of wRPS15 could potentially cost tens of billions in additional dollar-expenditure for fossil and / or nuclear generation capacity. There is a real possibility that carbon dioxide and other greenhouse gas (GHG) emission reductions will miss the California ...

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. Conjugate heat transfer analysis of multiple enclosures in prototype fast breeder reactor

    Energy Technology Data Exchange (ETDEWEB)

    Velusamy, K.; Balaubramanian, V.; Vaidyanathan, G.; Chetal, S.C. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    1995-09-01

    Prototype Fast Breeder Reactor (PFBR) is a 500 MWe sodium cooled reactor under design. The main vessel of the reactor serves as the primary boundary. It is surrounded by a safety vessel which in turn is surrounded by biological shield. The gaps between them are filled with nitrogen. Knowledge of temperature distribution prevailing under various operating conditions is essential for the assessment of structural integrity. Due to the presence of cover gas over sodium free level within the main vessel, there are sharp gradients in temperatures. Also cover gas height reduces during station blackout conditions due to sodium level rise in main vessel caused by temperature rise. This paper describes the model used to analyse the natural convection in nitrogen, conduction in structures and radiation interaction among them. Results obtained from parametric studies for PFBR are also presented.

  5. 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.

  6. The equal load-sharing model of cascade failures in power grids

    Science.gov (United States)

    Scala, Antonio; De Sanctis Lucentini, Pier Giorgio

    2016-11-01

    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 power 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".

  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. 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.

  10. 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

  11. 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.

  12. Final report of the inter institutional project ININ-CNSNS 'Source Terms specific for the CNLV'

    International Nuclear Information System (INIS)

    The purpose of the project inter institutional ININ-CNSNS 'Source Terms Specifies for the CNLV' it is the one of implanting in the computer CYBER (CDC 180-830) of the ININ, the 'Source Term Code Package' (STCP) and to make the operation tests and corresponding operation using the data of the sample problem, for finally to liberate the package, all time that by means of the analysis of the results it is consider appropriate. In this report the results of the are presented simulation of the sequence 'Energy Losses external' (Station blackout) and 'Lost total of CA with failure of the RCIC and success of the HPCS' both with data of the Laguna Verde Central. (Author)

  13. A review of postural orthostatic tachycardia syndrome.

    LENUS (Irish Health Repository)

    Carew, Sheila

    2012-01-31

    A 21-year-old female reports an 18-month history of light-headedness on standing. This is often associated with palpitations and a feeling of intense anxiety. She has had two black-outs in the past 12 months. She is not taking any regular medications. Her supine blood pressure was 126\\/84 mmHg with a heart rate of 76 bpm, and her upright blood pressure was 122\\/80 mmHg with a heart rate of 114 bpm. A full system examination was otherwise normal. She had a 12-lead electrocardiogram performed which was unremarkable. She was referred for head-up tilt testing. She was symptomatic during the test and lost consciousness at 16 min. Figure 1 summarizes her blood pressure and heart rate response to tilting. A diagnosis of postural orthostatic tachycardia syndrome with overlapping vasovagal syncope was made.

  14. DAKOTA reliability methods applied to RAVEN/RELAP-7.

    Energy Technology Data Exchange (ETDEWEB)

    Swiler, Laura Painton; Mandelli, Diego [Idaho National Laboratory, Idaho Falls, ID; Rabiti, Cristian [Idaho National Laboratory, Idaho Falls, ID; Alfonsi, Andrea [Idaho National Laboratory, Idaho Falls, ID

    2013-09-01

    This report summarizes the result of a NEAMS project focused on the use of reliability methods within the RAVEN and RELAP-7 software framework for assessing failure probabilities as part of probabilistic risk assessment for nuclear power plants. RAVEN is a software tool under development at the Idaho National Laboratory that acts as the control logic driver and post-processing tool for the newly developed Thermal-Hydraulic code RELAP-7. Dakota is a software tool developed at Sandia National Laboratories containing optimization, sensitivity analysis, and uncertainty quantification algorithms. Reliability methods are algorithms which transform the uncertainty problem to an optimization problem to solve for the failure probability, given uncertainty on problem inputs and a failure threshold on an output response. The goal of this work is to demonstrate the use of reliability methods in Dakota with RAVEN/RELAP-7. These capabilities are demonstrated on a demonstration of a Station Blackout analysis of a simplified Pressurized Water Reactor (PWR).

  15. An important year for Swiss Electricity Politics - President's speech at the shareholder's meeting of the Swiss Association of Electricity Enterprises

    International Nuclear Information System (INIS)

    This article presents the speech made by Rudolf Steiner, president of the Swiss Association of Electricity Enterprises, in Bad Ragaz in September 2004. Steiner comments on 2004 as being an important year with respect to energy politics in Switzerland. A public vote turned down the idea of opting out of nuclear energy, the Federal Court decided that the Restricted Trade Practices act was also applicable to the Swiss electricity supply industry and the EU parliament passed guidelines on the opening of the European power market. The effects of large-scale blackouts in America and Europe on the public's perception of secure supplies are commented on. The importance of the Association as a provider of services for its members and as a partner for the government is stressed

  16. Contingency-Constrained Unit Commitmentin Meshed Isolated Power Systems

    DEFF Research Database (Denmark)

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

    2015-01-01

    This paper presents a mixed-integer linear optimization problem for unit commitment and economic dispatch of power generators in a meshed isolated power system. The optimization problem is referred to as the optimal reserve planning problem (ORPP). The ORPP guarantees that the system frequency...... is kept above a predefined limit in the event of a contingency. The minimum frequency constraints are formulated using novel sufficient conditions that take into account the system inertia and the dynamics of the power generators. The proposed sufficient conditions are attractive from both a computational...... 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 ORPP...

  17. 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.

  18. 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

  19. Combining Agile and Traditional: Customer Communication in Distributed Environment

    Science.gov (United States)

    Korkala, Mikko; Pikkarainen, Minna; Conboy, Kieran

    Distributed development is a radically increasing phenomenon in modern software development environments. At the same time, traditional and agile methodologies and combinations of those are being used in the industry. Agile approaches place a large emphasis on customer communication. However, existing knowledge on customer communication in distributed agile development seems to be lacking. In order to shed light on this topic and provide practical guidelines for companies in distributed agile environments, a qualitative case study was conducted in a large globally distributed software company. The key finding was that it might be difficult for an agile organization to get relevant information from a traditional type of customer organization, even though the customer communication was indicated to be active and utilized via multiple different communication media. Several challenges discussed in this paper referred to "information blackout" indicating the importance of an environment fostering meaningful communication. In order to evaluate if this environment can be created a set of guidelines is proposed.

  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

  1. 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).

  2. 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

  3. 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...

  4. Intelligent decision support algorithm for distribution system restoration.

    Science.gov (United States)

    Singh, Reetu; Mehfuz, Shabana; Kumar, Parmod

    2016-01-01

    Distribution system is the means of revenue for electric utility. It needs to be restored at the earliest if any feeder or complete system is tripped out due to fault or any other cause. Further, uncertainty of the loads, result in variations in the distribution network's parameters. Thus, an intelligent algorithm incorporating hybrid fuzzy-grey relation, which can take into account the uncertainties and compare the sequences is discussed to analyse and restore the distribution system. The simulation studies are carried out to show the utility of the method by ranking the restoration plans for a typical distribution system. This algorithm also meets the smart grid requirements in terms of an automated restoration plan for the partial/full blackout of network. PMID:27512634

  5. Nonextensivity effect on radio-wave transmission in plasma sheath

    Science.gov (United States)

    Mousavi, A.; Esfandiari-Kalejahi, A.; Akbari-Moghanjoughi, M.

    2016-04-01

    In this paper, new theoretical findings on the application of magnetic field in effective transmission of electromagnetic (EM) waves through a plasma sheath around a hypersonic vehicle are reported. The results are obtained by assuming the plasma sheath to consist of nonextensive electrons and thermal ions. The expressions for the electric field and effective collision frequency are derived analytically in the framework of nonextensive statistics. Examination of the reflection, transmission, and absorption coefficients regarding the strength of the ambient magnetic field shows the significance of q-nonextensive parameter effect on these entities. For small values of the magnetic field, the transmission coefficient increases to unity only in the range of - 1 wave transmission through the nonextensive plasma sheath can take place using lower magnetic field strengths in the presence of superthermal electrons compared with that of Maxwellian ones. It is observed that superthermal electrons, with nonextensive parameter, q radio blackout for hypersonic flights.

  6. 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.

  7. Profound hypoglycemia-ύnduced by vaccinium corymbosum juice and laurocerasus fruit

    Directory of Open Access Journals (Sweden)

    Ahmet Hamdi Aktan

    2014-01-01

    Full Text Available 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 measured plasma glucose (PG level during loss of consciousness was 30 mg/dl. The profound hypoglycemia may be an unexpected side effect of an interaction between the chemical compositions of the two plants, occurred as a result of LO fruit intake that may have a strong PG-lowering effect or related to excessive intake of VC juice. Both plants may be considered in the alternative treatment of diabetes.

  8. Profound hypoglycemia-ınduced by vaccinium corymbosum juice and laurocerasus fruit.

    Science.gov (United States)

    Aktan, Ahmet Hamdi; Ozcelik, Abdullah; Cure, Erkan; Cure, Medine Cumhur; Yuce, Suleyman

    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 measured plasma glucose (PG) level during loss of consciousness was 30 mg/dl. The profound hypoglycemia may be an unexpected side effect of an interaction between the chemical compositions of the two plants, occurred as a result of LO fruit intake that may have a strong PG-lowering effect or related to excessive intake of VC juice. Both plants may be considered in the alternative treatment of diabetes. PMID:25097289

  9. Analysis of SBO ATWS for Maanshan PWR

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Che-Hao; Chen, Shao-Wen [National Tsing Hua Univ., Hsinchu, Taiwan (China). Inst. of Nuclear Engineering and Science; Wang, Jong-Rong; Shih, Chunkuan [National Tsing Hua Univ., Hsinchu, Taiwan (China). Inst. of Nuclear Engineering and Science; Nuclear and New Energy Education and Research Foundation, Hsinchu, Taiwan (China); Lin, Hao-Tzu [Atomic Energy Council, Taoyuan, Taiwan (China). Inst. of Nuclear Energy Research

    2015-11-15

    Station blackout anticipated transient without scram (SBO ATWS) is considered as loss of off-site and on-site power but no credit for automatic reactor trip. SBO ATWS causes reactor coolant pump (RCP) trip, loss of all main feedwater pumps and turbine trip, then the reactor coolant system (RCS) pressure rises rapidly due to loss of heat removal paths. The ASME Code Level C service limit criteria of 22.06 MPa (3200 psig) is assumed to be an unacceptable plant condition in SECY-83-293. The simulation is performed by TRACE which is a thermal-hydraulic code developed by U.S. NRC. Three different AFW flows are modeled to ensure the pressures will not be beyond the criteria. RCP seal-leakage is concerned as a SBLOCA due to loss of RCP seal-cooling. Four possible leakage flows are modeled to examine the reactor core water level and temperature variation.

  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. 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.

  12. 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...

  13. Dynamic Modeling of Cascading Failure in Power Systems

    CERN Document Server

    Song, Jiajia; Ghanavati, Goodarz; Hines, Paul D H

    2014-01-01

    The modeling of cascading failure in power systems is difficult because of the many different mechanisms involved; no single model captures all of these mechanisms. Understanding the relative importance of these different mechanisms is an important step in choosing which mechanisms need to be modeled for particular types of cascading failure analysis. This work presents a dynamic simulation model of both power networks and protection systems, which can simulate a wider variety of cascading outage mechanisms, relative to existing quasi-steady state (QSS) models. The model allows one to test the impact of different load models and protections on cascading outage sizes. This paper describes each module of the developed dynamic model and demonstrates how different mechanisms interact. In order to test the model we simulated a batch of randomly selected $N-2$ contingencies for several different static load configurations, and found that the distribution of blackout sizes and event lengths from the proposed dynamic...

  14. Contributing and consequential correlates of illicit substance use among students

    Directory of Open Access Journals (Sweden)

    Rehana Khalil

    2015-12-01

    Conclusions: It was found that majority of the respondents' friends were involved in drug use and less commonly their cousins and family members. Most of them started drug consumption at age between 15-19 years and were mainly doing it for recreational purposes; other reasons were social pressure or educational stress. The consequential correlates identified includes, behavioural attributes distorted relationship with family and friends, poor performance in education, and delinquent activities like imprisonment and other unlawful pursuits. Other attributes were medical including physical manifestation of substance abuse like blackouts, hepatitis B and C, increased heart rate, convulsions and lung infections. The psychological manifestations listed depression and anxiety, and impaired memory. [Int J Res Med Sci 2015; 3(12.000: 3446-3451

  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. 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.

  17. Elimination of the Inrush Current Phenomenon Associated with Single-Phase Offline UPS Systems

    Directory of Open Access Journals (Sweden)

    Syed Sabir Hussain Bukhari

    2016-02-01

    Full Text Available Critical load applications always rely on UPS systems to uphold continuous power during abnormal grid conditions. In case of any power disruption, an offline UPS system starts powering the load to avoid blackout. However, this process can root the momentous inrush current for the transformer installed before the load. The consequences of inrush current can be the reduction of output voltage and tripping of protective devices of the UPS system. Furthermore, it can also damage the sensitive load and decrease the transformer’s lifetime. To prevent the inrush current, and to avoid its disruptive effects, this research suggests an offline UPS system based on a current regulated inverter that eliminates the inrush current while powering the transformer coupled loads. A detailed comparative analysis of the conventional and proposed topologies is presented and the experiment was performed by using a small prototype to validate the performance, and operation of the proposed topology.

  18. Study on a decay heat removal system of light water reactors using air coolers

    International Nuclear Information System (INIS)

    In the present work, a passive decay heat removal system for light water reactors (LWRs) based on a new concept is studied referring to an air cooling system (ACS) of the fast breeder reactor Monju. The present study will contribute to the reduction of severe accident risks of nuclear power plants. In this system, a blower for an air cooler (AC) is operated using the rotation of a small steam turbine by generated steam in order to cool heat transfer tubes by forced convection of air. The purpose of the present work is to investigate the plant transient caused by a station blackout (SBO) using the plant system code NETFLOW++ and decay heat removal characteristics. A calculation model is the Advanced Boiling Water Reactor (ABWR) in Japan. (author)

  19. Behaviour of isolation condensers (ICs) in accident of Fukushima Daiichi Nuclear Power Plant, Unit 1, based on thermodynamic model. And yet, the IC was working after Tsunami arrival

    International Nuclear Information System (INIS)

    In order to investigate the process of Accident of Fukushima Nuclear Plants, an accident scenario of Fukushima Daiichi Nuclear Power Plant, Unit 1 is analyzed from the data open to the public. Phase equilibrium process model and adiabatic expansion model were introduced. Original data reported in the first stage of the accident were examined to clarify the behaviour of the isolation condensers (ICs) which are generally believed unfunctional after the arrival of Tsunami and station blackout. The original data and observation reports verified that the so called 'fail safe' system to close the valves in IC did not work properly due to the shutdown of AC power. The reports also showed the evidence that the operators injected water to the storage tank of IC. (author)

  20. 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.

  1. 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。

  2. 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.

  3. Optimal Management and Design of Energy Systems under Atmospheric Uncertainty

    Science.gov (United States)

    Anitescu, M.; Constantinescu, E. M.; Zavala, V.

    2010-12-01

    The generation and distpatch of electricity while maintaining high reliability levels are two of the most daunting engineering problems of the modern era. This was demonstrated by the Northeast blackout of August 2003, which resulted in the loss of 6.2 gigawatts that served more than 50 million people and which resulted in economic losses on the order of $10 billion. In addition, there exist strong socioeconomic pressures to improve the efficiency of the grid. The most prominent solution to this problem is a substantial increase in the use of renewable energy such as wind and solar. In turn, its uncertain availability—which is due to the intrinsic weather variability—will increase the likelihood of disruptions. In this endeavors of current and next-generation power systems, forecasting atmospheric conditions with uncertainty can and will play a central role, at both the demand and the generation ends. User demands are strongly correlated to physical conditions such as temperature, humidity, and solar radiation. The reason is that the ambient temperature and solar radiation dictate the amount of air conditioning and lighting needed in residential and commercial buildings. But these potential benefits would come at the expense of increased variability in the dynamics of both production and demand, which would become even more dependent on weather state and its uncertainty. One of the important challenges for energy in our time is how to harness these benefits while “keeping the lights on”—ensuring that the demand is satisfied at all times and that no blackout occurs while all energy sources are optimally used. If we are to meet this challenge, accounting for uncertainty in the atmospheric conditions is essential, since this will allow minimizing the effects of false positives: committing too little baseline power in anticipation of demand that is underestimated or renewable energy levels that fail to materialize. In this work we describe a framework for the

  4. 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.

  5. 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".

  6. 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.

  7. 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.

  8. 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.

  9. Transformer winding defects identification based on a high frequency method

    Science.gov (United States)

    Florkowski, Marek; Furgał, Jakub

    2007-09-01

    The transformer diagnostic methods are systematically being improved and extended due to growing requirements for reliability of power systems in terms of uninterrupted power supply and avoidance of blackouts. Those methods are also driven by longer lifetime of transformers and demand for reduction of transmission and distribution costs. Hence, the detection of winding faults in transformers, both in exploitation or during transportation is an important aspect of power transformer failure prevention. The frequency response analysis method (FRA), more and more frequently used in electric power engineering, has been applied for investigations and signature analysis based on the admittance and transfer function. The paper presents a novel approach to the identification of typical transformer winding problems such as axial or radial movements or turn-to-turn faults. The proposed transfer function discrimination (TFD) criteria are based on the derived transfer function ratios, manifesting higher sensitivity.

  10. Energy solutions for sustainable development. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Soenderberg Petersen, L.; Larsen, Hans (eds.)

    2007-05-15

    The Risoe International Energy Conference took place 22 - 24 May 2007. The conference focused on: 1) Future global energy development options. 2) Scenario and policy issues. 3) Measures to achieve low-level stabilization at, for example, 500 ppm CO2 concentrations in the atmosphere. 4) Local energy production technologies such as fuel cells, hydrogen, bio-energy and wind energy. 5) Centralized energy technologies such as clean coal technologies. 6) Providing renewable energy for the transport sector. 7) Systems aspects, differences between the various major regions throughout the world. 8) End-use technologies, efficiency improvements and supply links. 9) Security of supply with regard to resources, conflicts, black-outs, natural disasters and terrorism. (au)

  11. High performance robotic traverse of desert terrain.

    Energy Technology Data Exchange (ETDEWEB)

    Whittaker, William (Carnegie Mellon University, Pittsburgh, PA)

    2004-09-01

    This report presents tentative innovations to enable unmanned vehicle guidance for a class of off-road traverse at sustained speeds greater than 30 miles per hour. Analyses and field trials suggest that even greater navigation speeds might be achieved. The performance calls for innovation in mapping, perception, planning and inertial-referenced stabilization of components, hosted aboard capable locomotion. The innovations are motivated by the challenge of autonomous ground vehicle traverse of 250 miles of desert terrain in less than 10 hours, averaging 30 miles per hour. GPS coverage is assumed to be available with localized blackouts. Terrain and vegetation are assumed to be akin to that of the Mojave Desert. This terrain is interlaced with networks of unimproved roads and trails, which are a key to achieving the high performance mapping, planning and navigation that is presented here.

  12. 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.

  13. 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...

  14. 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.

  15. 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.

  16. Using SDO-EVE Satellite Data to Model for the First Time how Large Solar Flares Influence the Earths Ionosphere

    Science.gov (United States)

    Jensen, Joseph; Sojka, Jan; Schunk, Robert; David, Michael; Woods, Tom; Eparvier, Frank

    2012-10-01

    The earth's ionosphere is very important in our everyday life. During large solar flares the ionosphere expands to the point of disrupting communications from GPS, military, and commercial communications satellites, and even radio blackouts can occur. The EVE instrument on the SDO satellite has given unprecedented spectral resolution for the Extreme Ultraviolet(EUV) spectrum with a time cadence of 10 seconds. This has made it possible to analyze flare spectra as never before. Using the Time Dependent Ionospheric Model (TDIM) we have input this new spectral data for large solar flares and analyzed the effect on the ionosphere. We take as a test case the X1.6 flare on March 9, 2011. Even this minor X-class provides insight into how the ionospheric layers respond differently to solar flares.

  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. 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)

  19. Multi-Agent System Based Special Protection and Emergency Control Scheme against Cascading Events in Power System

    DEFF Research Database (Denmark)

    Liu, Zhou

    , according to the variations of power system operation, an overload prediction algorithm based on impedance sensitivity is proposed here to distinguish the emergency states from a remote fault. These methods combined together, which can give a fast identification of the emergency states and a clear mapping...... the proposed protection strategy in this thesis, a real time simulation platform based on Real Time Digital Simulator (RTDS) and LabVIEW is built. In this platform, the cases of cascaded blackouts are simulated on the test system simplified from the East Denmark power system. For the MAS based control system......, the distributed power system agents are set up in RTDS, while the agents in higher level are designed by LabVIEW toolkits. The case studies and simulation results demonstrate the effectiveness of real time application of the proposed MAS based special protection and emergency control scheme against the cascaded...

  20. 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

  1. An important year for Swiss Electricity Politics - President's speech at the shareholder's meeting of the Swiss Association of Electricity Enterprises; Strompolitisch relevantes Jahr

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, R

    2004-07-01

    This article presents the speech made by Rudolf Steiner, president of the Swiss Association of Electricity Enterprises, in Bad Ragaz in September 2004. Steiner comments on 2004 as being an important year with respect to energy politics in Switzerland. A public vote turned down the idea of opting out of nuclear energy, the Federal Court decided that the Restricted Trade Practices act was also applicable to the Swiss electricity supply industry and the EU parliament passed guidelines on the opening of the European power market. The effects of large-scale blackouts in America and Europe on the public's perception of secure supplies are commented on. The importance of the Association as a provider of services for its members and as a partner for the government is stressed.

  2. Power System Stability Using Decentralized Under Frequency and Voltage Load Shedding

    DEFF Research Database (Denmark)

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

    2014-01-01

    Load shedding (LS) is the last emergency control action against voltage and frequency instability or even system blackout. In conventional Under Frequency Load Shedding (UFLS) relays, LS is carried out by curtailing a fixed amount of load when the frequency declines below a set of predefined...... of disturbance location. In this paper, to aim adaptive performance of the relays, the amount of load shed in each stage is determined proportional to the measured Rate of Change of Frequency (ROCOF). In order to localize the LS scheme close to the disturbance place, this scheme utilizes the voltage drop...... information to shed the loads with higher voltage decay first. Therefore, this approach deals with coordination of voltage and frequency information instead of independent methods. Numerical simulations which are carried out in DigSilent PowerFactory software confirm the efficiency of proposed methodology...

  3. Real-Time Stability Assessment based on Synchrophasors

    DEFF Research Database (Denmark)

    Jóhannsson, Hjörtur; Garcia-Valle, Rodrigo; Weckesser, Johannes Tilman Gabriel;

    2011-01-01

    eventually cause in very sharp decline in system voltages at intermediate locations between the two groups as the angular separation approaches 180◦. In order to receive an early warning for the occurrence of such type of blackouts, the boundaries of the system generators aperiodic small-signal stability...... are suggested to be monitored. For that purpose, method for real-time assessment of aperiodic small-signal rotor angle stability is presented. The approach is based on an element-wise assessment of individual synchronous machines where the aim is to determine the maximum steady state power that each synchronous...... generator can inject into the system. The limits for maximum injectable power represent the boundary for aperiodic small signal stability. The concept of the proposed method is tested on two different systems. The results show that the method is capable of accurately detecting when a given machine crosses...

  4. Adaptive Voltage Stability Protection Based on Load Identification Using Phasor Measurement Units

    DEFF Research Database (Denmark)

    Liu, Leo; Bak, Claus Leth; Chen, Zhe;

    2011-01-01

    With the continuously increasing power demands, the power system is much closer to its limits. As a result, the power system is more vulnerable to disturbances and faults. The voltage instability is one of the main reasons of cascading trip, wide-area blackout, and even the system-wide voltage...... collapse. In this paper, the online load identification using measurement-based approach based on Phasor Measurement Units (PMU) was proposed to evaluate the proximity to voltage instability in order to prevent voltage collapse. In the scenarios of disturbances, the proximity to voltage collapse...... with respect to load characteristics was evaluated. Based on different load characteristics, different control and protection schemes were implemented, i.e. shunt capacitor connection, on-load tap changer blocking and load shedding. The results showed that load-based adaptive voltage control and protection...

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

    DEFF Research Database (Denmark)

    Liu, Leo; Rather, Zakir Hussain; Chen, Zhe;

    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...... of western Danish power system which is characterized by its large scale wind energy penetration and high proportion of distributed generation (DG). DIgSILENT PowerFactory is adopted for the power system simulation and Salford Predictive Modeler (SPM) is used for data mining.......-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 to train the DT and key to this approach lies on the accuracy of DT. This paper proposes contingency oriented DT...

  6. 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......There has been a high penetration level of Distributed Generations (DGs) in distribution systems in Denmark. Even more DGs are expected to be installed in the coming years. With that, to utilize them in maintaining the security of power supply is of great concern for Danish utilities. During...... 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...

  7. City of Hoboken energy surety analysis :

    Energy Technology Data Exchange (ETDEWEB)

    Stamp, Jason Edwin; Baca, Michael J.; Munoz-Ramos, Karina; Schenkman, Benjamin L.; Eddy, John P.; Smith, Mark A.; Guttromson, Ross; Henry, Jordan M.; Jensen, Richard Pearson

    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.

  8. The Impact of the Topology on Cascading Failures in Electric Power Grids

    CERN Document Server

    Koç, Yakup; Van Mieghem, Piet; Kooij, Robert E; Brazier, Frances M T

    2014-01-01

    Cascading failures are one of the main reasons for blackouts in power transmission grids. The topology of a power grid, together with its operative state determine, for the most part, the robustness of the power grid against cascading failures. Secure electrical power supply requires, together with careful operation, a robust design of the electrical power grid topology. This paper investigates the impact of a power grid topology on its robustness against cascading failures. Currently, the impact of the topology on a grid robustness is mainly assessed by using purely topological approaches that fail to capture the essence of electric power flow. This paper proposes a metric, the effective graph resistance, that relates the topology of a power grid to its robustness against cascading failures by deliberate attacks, while also taking the fundamental characteristics of the electric power grid into account such as power flow allocation according to Kirchoff Laws. Experimental verification shows that the proposed ...

  9. The impact of the topology on cascading failures in a power grid model

    Science.gov (United States)

    Koç, Yakup; Warnier, Martijn; Mieghem, Piet Van; Kooij, Robert E.; Brazier, Frances M. T.

    2014-05-01

    Cascading failures are one of the main reasons for large scale blackouts in power transmission grids. Secure electrical power supply requires, together with careful operation, a robust design of the electrical power grid topology. Currently, the impact of the topology on grid robustness is mainly assessed by purely topological approaches, that fail to capture the essence of electric power flow. This paper proposes a metric, the effective graph resistance, to relate the topology of a power grid to its robustness against cascading failures by deliberate attacks, while also taking the fundamental characteristics of the electric power grid into account such as power flow allocation according to Kirchhoff laws. Experimental verification on synthetic power systems shows that the proposed metric reflects the grid robustness accurately. The proposed metric is used to optimize a grid topology for a higher level of robustness. To demonstrate its applicability, the metric is applied on the IEEE 118 bus power system to improve its robustness against cascading failures.

  10. 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.

  11. Leak rate analysis of the Westinghouse Reactor Coolant Pump

    International Nuclear Information System (INIS)

    An independent analysis was performed by ETEC to determine what the seal leakage rates would be for the Westinghouse Reactor Coolant Pump (RCP) during a postulated station blackout resulting from loss of ac electric power. The object of the study was to determine leakage rates for the following conditions: Case 1: All three seals function. Case 2: No. 1 seal fails open while Nos. 2 and 3 seals function. Case 3: All three seals fail open. The ETEC analysis confirmed Westinghouse calculations on RCP seal performance for the conditions investigated. The leak rates predicted by ETEC were slightly lower than those predicted by Westinghouse for each of the three cases as summarized below. Case 1: ETEC predicted 19.6 gpm, Westinghouse predicted 21.1 gpm. Case 2: ETEC predicted 64.7 gpm, Westinghouse predicted 75.6 gpm. Case 3: ETEC predicted 422 gpm, Westinghouse predicted 480 gpm. 3 refs., 22 figs., 6 tabs

  12. Evaluation of an accident management strategy of emergency water injection using fire engines in a typical pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-15

    Following the Fukushima accident, a special safety inspection was conducted in Korea. The inspection results show that Korean nuclear power plants have no imminent risk for expected maximum potential earthquake or coastal flooding. However long- and short-term safety improvements do need to be implemented. One of the measures to increase the mitigation capability during a prolonged station blackout (SBO) accident is installing injection flow paths to provide emergency cooling water of external sources using fire engines to the steam generators or reactor cooling systems. This paper illustrates an evaluation of the effectiveness of external cooling water injection strategies using fire trucks during a potential extended SBO accident in a 1,000 MWe pressurized water reactor. With regard to the effectiveness of external cooling water injection strategies using fire engines, the strategies are judged to be very feasible for a long-term SBO, but are not likely to be effective for a short-term SBO.

  13. 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.

  14. What is demand response? Contributing to secure security-of-supply at the electricity markets

    International Nuclear Information System (INIS)

    There is a common understanding that demand response can reduce the total costs of electricity reliability. There has especially been a growing interest in the electricity market where high spot prices in peak periods and blackouts have recently been seen. It is not easy from the existing literature to find a common definition of demands response. Often the term demand response is used broadly without looking at the time dimension. However, it does not make sense to talk about demand response without talking about when, for how long the energy is used or saved, and at which costs. This paper surveys these subjects and set up a systematic grouping of the different characteristics of demand response. It especially looks at the time dimension. (au)

  15. Our energies have a future. A future without CO2. Areva in 2005

    International Nuclear Information System (INIS)

    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.)

  16. California customer load reductions during the electricity crisis: Did they help to keep the lights on?

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, Charles A.; Eto, Joseph H.; Barbose, Galen L.

    2002-05-01

    Recurring electricity shortages and rolling blackouts were widely forecasted for summer 2001 in California. Despite these predictions, blackouts were never ordered - in large part, due to the dramatic reductions in electricity use throughout the state. Compared to summer 2000, Californians reduced electricity usage by 6 percent and average monthly peak demand by 8 percent. Our analysis suggests that these reductions were not caused by either the weather or the downturn in the state's economy; rather, they were the result of extraordinary efforts by Californians to reduce electricity consumption. Based on the California Independent System Operator's (CAISO) available operating reserve margin during summer 2001, we estimate that the peak load reductions, which ranged between 3,200 and 5,600 MW in the four summer months, potentially avoided between 50 and 160 hours of rolling blackouts. This extraordinary response by Californians can be attributed to several factors including media coverage and informational campaigns that affected public awareness and understanding, real and/or perceived increases in electricity rates, and various policies and programs deployed by state policymakers and regulators to facilitate customer load reductions. Among these programs, we review the state's 20/20 rebate program, the utilities' energy efficiency programs, programs or initiatives implemented by the California Energy Commission and other state agencies, and load management and demand response programs offered by the state's investor-owned electric utilities and the CAISO. We estimate that energy efficiency and onsite generation projects that were initiated in 2001 will account for about 1,100 MW of customer load reductions, once all projects are installed. These savings represent about 25-30 percent of the observed load reductions and are likely to persist for many years. The persistence of the remaining savings, which were due to changes that customers

  17. 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.

  18. The USGS geomagnetism program and its role in space weather monitoring

    Science.gov (United States)

    Love, J.J.; Finn, C.A.

    2011-01-01

    Magnetic storms result from the dynamic interaction of the solar wind with the coupled magnetospheric-ionospheric system. Large storms represent a potential hazard for the activities and infrastructure of a modern, technologically based society [Baker et al., 2008]; they can cause the loss of radio communications, reduce the accuracy of global positioning systems, damage satellite electronics and affect satellite operations, increase pipeline corrosion, and induce voltage surges in electric power grids, causing blackouts. So while space weather starts with the Sun and is driven by the solar wind, it is on, or just above, the surface of the Earth that the practical effects of space weather are realized. Therefore, ground-based sensor networks, including magnetic observatories [Love, 2008], play an important role in space weather monitoring. Copyright 2011 by the American Geophysical Union.

  19. The USGS Geomagnetism Program and its role in Space-Weather Monitoring

    Science.gov (United States)

    Love, Jeffrey J.; Finn, Carol A.

    2011-01-01

    Magnetic storms result from the dynamic interaction of the solar wind with the coupled magnetospheric-ionospheric system. Large storms represent a potential hazard for the activities and infrastructure of a modern, technologically based society [Baker et al., 2008]; they can cause the loss of radio communications, reduce the accuracy of global positioning systems, damage satellite electronics and affect satellite operations, increase pipeline corrosion, and induce voltage surges in electric power grids, causing blackouts. So while space weather starts with the Sun and is driven by the solar wind, it is on, or just above, the surface of the Earth that the practical effects of space weather are realized. Therefore, ground-based sensor networks, including magnetic observatories [Love, 2008], play an important role in space weather monitoring.

  20. 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.)

  1. Willingness to pay for public services and quality of supply in the electricity area

    International Nuclear Information System (INIS)

    This report for the Swiss Federal Office of Energy (SFOE) takes a look at the results of a study made on the willingness to pay for public services and quality of supply in the electricity area. First, the starting point of the study and definitions of quality of supply and security of supply are noted. The methods used in the study are presented and macro-economic aspects are reviewed. The costs of black-outs are examined and the carrying out of surveys in the electricity market is discussed. The results of surveys made in households and commercial enterprises concerning the willingness to pay for security of supply and the costs incurred when supplies fail are presented and discussed. The report is completed with a comprehensive list of references and an appendix containing the results of the various tests and surveys made.

  2. Con Edison power failure of July 13 and 14, 1977. Final staff report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    On July 13, 1977 the entire electric load of the Con Edison system was lost, plunging New York City and Westchester County into darkness. The collapse resulted from a combination of natural events, equipment malfunctions, questionable system-design features, and operating errors. An attempt is made in this report to answer the following: what were the specific causes of the failure; if equipment malfunctions and operator errors contributed, could they have been prevented; to what extent was Con Edison prepared to handle such an emergency; and did Con Edison plan prudently reserve generation, for reserve transmission capability, for automatic equipment to protect its system, and for proper operator response to a critical situation. Following the introductory and summary section, additional sections include: the Consolidated Edison system; prevention of bulk power-supply interruptions; the sequence of failure and restoration; analysis of the July 1977 power failure; restoration sequence and equipment damage assessment; and other investigations of the blackout. (MCW)

  3. Recurarization in a successfully managed case of posterior reversible encephalopathy syndrome (PRES) for emergency caesarean section.

    Science.gov (United States)

    Parikh, Suchita; Tavri, Snehlata; Mohite, Shubha

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic syndrome of headache, visual changes, altered mental status and seizures with radiologic findings of posterior cerebral white matter edema. It is seen in hypertensive encephalopathy, renal failure, and autoimmune disorders or in patients on immunosuppressants. We report a case of 24-year-old primigravida who presented at term with sudden onset hypertension, neurological deficits, and an episode of the visual blackout. Magnetic resonance imaging showed features suggestive of PRES. She was posted for emergency lower segment cesarean section. General anesthesia was administered and blood pressure managed with antihypertensives. Postoperatively, she developed acute respiratory depression after prophylactic administration of injection magnesium sulfate. This case highlights that good clinical acumen along with early neuroimaging helps in prompt diagnosis, treatment and prevention of long-term neurological sequelae in PRES and the anesthetic implications of administering magnesium sulfate in the immediate post neuromuscular block reversal phase. PMID:27212776

  4. Resistance to reinforcement change in multiple and concurrent schedules assessed in transition and at steady state.

    Science.gov (United States)

    McLean, A P; Blampied, N M

    1995-01-01

    Behavioral momentum theory relates resistance to change of responding in a multiple-schedule component to the total reinforcement obtained in that component, regardless of how the reinforcers are produced. Four pigeons responded in a series of multiple-schedule conditions in which a variable-interval 40-s schedule arranged reinforcers for pecking in one component and a variable-interval 360-s schedule arranged them in the other. In addition, responses on a second key were reinforced according to variable-interval schedules that were equal in the two components. In different parts of the experiment, responding was disrupted by changing the rate of reinforcement on the second key or by delivering response-independent food during a blackout separating the two components. Consistent with momentum theory, responding on the first key in Part 1 changed more in the component with the lower reinforcement total when it was disrupted by changes in the rate of reinforcement on the second key. However, responding on the second key changed more in the component with the higher reinforcement total. In Parts 2 and 3, responding was disrupted with free food presented during intercomponent blackouts, with extinction (Part 2) or variable-interval 80-s reinforcement (Part 3) arranged on the second key. Here, resistance to change was greater for the component with greater overall reinforcement. Failures of momentum theory to predict short-term differences in resistance to change occurred with disruptors that caused greater change between steady states for the richer component. Consistency of effects across disruptors may yet be found if short-term effects of disruptors are assessed relative to the extent of change observed after prolonged exposure. PMID:16812750

  5. What do customers want from improved residential electricity services? Evidence from a choice experiment

    International Nuclear Information System (INIS)

    Improvements in customer satisfaction as well as product/service quality represent a common objective of all businesses, and electricity services are no exception. Using choice experiments and a mixed logit model, this study quantitatively analyzes customers' preferences and their marginal willingness to pay for improved residential electricity services. The study provides an ex ante evaluation of customers' acceptance of hypothetical electricity services. According to the results, customers consider the electricity bill and the electricity mix as the two most important attributes when choosing their electricity services. Customers are willing to pay 2.2% more in the average electricity bill (an additional monthly electricity bill of KRW 1,064; USD 0.96) for a significant increase in the share of renewable energy, which is far less than the actual cost of achieving this renewable target. Therefore, it is better to maintain the current electricity mix in principle, and the renewable share should be gradually expanded instead of making a sudden change in the electricity mix. In addition, customers are willing to pay KRW 6,793 (USD 6.15) more to reduce blackouts once in a year and KRW 64/year (USD 0.06/year) to reduce a minute of each blackout. -- Highlights: •Customers' preferences for improved residential electricity services are analyzed. •Empirical setting is a sample of residents in South Korea. •The electricity bills and electricity mix are important to customers. •Increase in electricity bill of different electricity mix is considered

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

    Energy Technology Data Exchange (ETDEWEB)

    Liu, DongLin, E-mail: donglinliu@stu.xidian.edu.cn; Li, XiaoPing; Xie, Kai; Liu, ZhiWei [School of Aerospace Science and Technology, Xidian University, Xi' an 710071 (China)

    2015-10-15

    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.

  7. Combined loss of primary and secondary coolant AC pump power design-basis event for the K-reactor safety analysis report

    International Nuclear Information System (INIS)

    The combined loss of alternating-current (ac) power to the primary coolant and secondary coolant system pumps has been included as a design-basis event in Chap. 15 of the safety analysis report for the K reactor at the U.S. Department of Energy's Savannah River site (SRS) nuclear materials production complex near Aiken, South Carolina. This event can arise from a disruption of the entire 115-kV SRS power grid or a lesser disturbance affecting the K-reactor area, combined with a failure of the standby emergency power sources. The first scenario is referred to as a open-quotes station blackout,close quotes and the second scenario is designated as a open-quotes mini-blackout.close quotes This is a condition-11 event (incident of moderate frequency) per the criterion (frequency of occurrence ≥ 1 x 10-6 per year) for credible eventualities in the design-basis envelope. The event causes the primary coolant flow to drop and stabilize at ∼27% of its full level (5.83 + 05 ell/min). Likewise, the secondary coolant flow drops and settles also at ∼27% of its full level (6.36 x 105 ell/min). The final primary coolant flow is maintained by the reduced pumping provided by diesel powered direct-current motors. The final secondary coolant flow is driven by gravity from the height differential between the supply and discharge basins. Both flows coast down gradually due to the action of flywheels in all of the six primary coolant pumps and in two of the ten secondary coolant pumps

  8. Use of VIIRS DNB Data to Monitor Power Outages and Restoration for Significant Weather Events

    Science.gov (United States)

    Jedlovec, Gary; Molthan, Andrew

    2008-01-01

    NASA fs Short-term Prediction Research and Transition (SPoRT) project operates from NASA's Marshall Space Flight Center in Huntsville, Alabama. The team provides unique satellite data to the National Weather Service (NWS) and other agencies and organizations for weather analysis. While much of its work is focused on improving short-term weather forecasting, the SPoRT team supported damage assessment and response to Hurricane Superstorm Sandy by providing imagery that highlighted regions without power. The team used data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite. The VIIRS low-light sensor, known as the day-night-band (DNB), can detect nighttime light from wildfires, urban and rural communities, and other human activity which emits light. It can also detect moonlight reflected from clouds and surface features. Using real time VIIRS data collected by our collaborative partner at the Space Science and Engineering Center of the University of Wisconsin, the SPoRT team created composite imagery to help detect power outages and restoration. This blackout imagery allowed emergency response teams from a variety of agencies to better plan and marshal resources for recovery efforts. The blackout product identified large-scale outages, offering a comprehensive perspective beyond a patchwork GIS mapping of outages that utility companies provide based on customer complaints. To support the relief efforts, the team provided its imagery to the USGS data portal, which the Federal Emergency Management Agency (FEMA) and other agencies used in their relief efforts. The team fs product helped FEMA, the U.S. Army Corps of Engineers, and U.S. Army monitor regions without power as part of their disaster response activities. Disaster responders used the images to identify possible outages and effectively distribute relief resources. An enhanced product is being developed and integrated into a web

  9. The extra-atmospheric masses of small meteoric fireballs from the Prairie and the Canadian camera networks.

    Science.gov (United States)

    Popelenskaya, N.

    2007-08-01

    Existing methods of definition of extra-atmospheric masses of small meteoric bodies according to supervision of their movement in an atmosphere contain the certain arbitrariness. Vigorous attempts to overcome a divergence of results of calculations on the basis of various approaches often lead to physically incorrect conclusions. The output consists in patient accumulation of estimations and calculations for gradual elimination uncertainties. The equations of meteoric physics include two dimensionless parameters - factor ablation ? and factor of braking ?. In work are cited the data processing supervision of small meteors Prairie and Canadian networks, by a finding of values of parameters ? and ? with use of a method of the least squares. Also values of heights blackout a meteor which turn out from conditions of full destruction or final braking with use of the received values of ? and ? are considered. In prevailing number of supervision for considered meteors braking is insignificant. Results of calculations of height of blackout meteors confirm suitability of the approximations used in work for the description of movement of small meteors. In work results of calculation of extra-atmospheric masses with use of factor of braking for meteoric bodies of the spherical form with density of an ice and a stone are presented. On the basis of the received results discrepancy of photometric masses to values of masses of the input, received on observable braking proves to be true. In most cases received magnitude of masses essentially less photometric masses. Processing of supervision of small meteors Prairie and Canadian camera networks has shown, that the so-called photometric mass mismatches values of mass of the input, defined on observable braking. Acceptance of photometric value as the mass defining braking of a body, leads to obviously underestimated values of density of substance meteoric body. The further researches on specification of interpretation of supervision

  10. KAPS level-1 PSA- analysis of 6.6 kV class-IV power supply failure as initiating event

    International Nuclear Information System (INIS)

    Full text: For Kakrapar atomic power station (KAPS) level-l probabilistic safety analysis (PSA) studies failure of 6.6 kV CL-IV power supply system resulting from failure of both the routes of class-IV buses viz., route via buses A, B, C and route via buses F, G, H is considered as one of the initiating events for analysis. This can happen due to grid problems or due to combinations of component failures from both the routes. This event is one of the most important transient events in station transient analysis as it could lead to scenarios like station blackout depending upon the availability of emergency power supply system i.e.the diesel generator system. Upon failure of class-IV power, reactor trips on no PCP on either side followed by high PHT pressure trip. Following this event if class III is available, no safety system gets affected and the mode of decay heat removal and long-term reactivity control are same as normally followed. If class-III fails, reactor has to be crash cooled and fire water should be injected to SGs for decay heat removal. Class-IV failure followed by class-III failure leads to a station blackout scenario in which a number of front line systems become available. Event tree was developed showing the mitigating functions/ systems required sequentially for safe termination of the initiating event (IE). To estimate the accident sequence frequencies the success and failure probabilities of these mitigating functions/ systems were calculated by fault tree methods. The IE frequency estimates have been derived from experience at KAPS station. For component failure probabilities a judicious mix of generic and plant specific data was used. The details and results of the assessment are presented in the paper

  11. Vulnerability to terrorist attacks in European electricity decarbonisation scenarios: Comparing renewable electricity imports to gas imports

    International Nuclear Information System (INIS)

    The decarbonised future European electricity system must remain secure: reliable electricity supply is a prerequisite for the functioning of modern society. Scenarios like Desertec, which partially rely on solar power imports from the Middle East and North Africa, may be attractive for decarbonisation, but raise concerns about terrorists interrupting supply by attacking the long, unprotected transmission lines in the Sahara. In this paper, I develop new methods and assess the European vulnerability to terrorist attacks in the Desertec scenario. I compare this to the vulnerability of today's system and a decarbonisation scenario in which Europe relies on gas imports for electricity generation. I show that the vulnerability of both gas and electricity imports is low, but electricity imports are more vulnerable than gas imports, due to their technical characteristics. Gas outages (and, potentially, resulting blackouts) are the very unlikely consequence even of very high-number attacks against the gas import system, whereas short blackouts are the potential consequence of a few attacks against the import electricity lines. As the impacts of all except extreme attacks are limited, terrorists cannot attack energy infrastructure and cause spectacular, fear-creating outages. Both gas and electricity import infrastructure are thus unattractive and unlikely terrorist targets. - Highlights: • A comparison of terrorism risks of importing solar power and gas for power generation. • Both scenarios show low vulnerability to terrorist attacks. • Within low vulnerabilities, gas imports are less vulnerable than electricity imports. • Causing spectacular, large and long outages is very difficult for attacker. • The attractiveness of gas and power import infrastructure as terrorist target is low

  12. Behaviour analysis of AC-600 passive safety systems

    International Nuclear Information System (INIS)

    Southwest Center of Reactor Engineering Research and Design has finished the first step conceptual design of 600 mwe advanced PWR (AC-600). The main research emphases of AC-600 conceptual design include the advanced reactor core, the passive safety systems and the simplification. The passive safety systems of AC-600 consist of two reactor make up water tanks, two accumulators, two emergency feedwater tanks, two emergency natural draft air condensers, a containment water jacket and an enhanced primary cycle natural circulation flow system. 25% of the rated reactor power can be removed by the natural circulation cooling. The full pressure reactor make up water tanks are able to provide enough borated water which would be injected into the reactor coolant system during small LOCA. The coolant natural circulations can be established in the primary system and the passive secondary emergency feedwater system, removing residual heat from the reactor core to the atmosphere when station blackout occurs. It is indicated from analysis that the containment diameter of AC-600 is about 35 m. The large tanks and the large vertical distances between the tanks and reactor core are the main reason of using the big containment. It is also indicated from analysis that the low head safety injection pumps are required in AC-600 design to assure the recirculation system operation when large LOCA occurs. The reliability of AC-600 engineered safety systems is increased because the function of the passive safety systems is conducted through the immutable natural laws. The paper discusses the natural circulation ability and safety behavior of the passive safety systems during LOCA or station blackout for AC-600. The passive limits to excess reactivity and thermal hydraulic transients are also preliminarily discussed. Figs and tabs

  13. October 29-31, 2003 geomagnetic storm: geomagnetically induced currents and their relation to problems in the Swedish high-voltage power transmission system

    Science.gov (United States)

    Pulkkinen, A. A.; Lindahl, S.; Viljanen, A.; Pirjola, R.

    2004-12-01

    In October 30, 2003, an ongoing geomagnetic superstorm knocked down a part of the high-voltage power transmission system in southern Sweden operated by the Sydkraft company. The blackout lasted for an hour and left about 50000 people without electricity. The incident was probably the most severe GIC failure observed since the well-known March 1989 Québec blackout and thus the problems in a Swedish system deserve a closer look. The geophysical background and the impacts on the Swedish high-voltage power transmission system of the October 29-31, 2003 geomagnetic storm are described in the study at hand. It was seen that athough no serious problems in North-America have been reported, the "three-phase" storm produced exceptionally large geomagnetic activity at the Fennoscandian auroral region. It was also seen that GIC modeled for southern Sweden region using very simplistic methods were able to explain the times of the failures in the Swedish system thus confirming the sources of experienced problems and adding also GIC to the long list of causes of technological impacts of the storm. Though the great diversity of the GIC drivers are addresses in the study, the problems in operating the Swedish system during the exceptionally intense storm of October 29-31, 2003 are attributed geophysically to substorms, SSCs and enhanced ionospheric convection all of which were creating large and complex geoelectric fields capable of driving large GIC. Based on the basic two-fold nature of the failure-related geoelectric field characteristics, a semi-deterministic approach for forecasting GIC-related geomagnetic activity in which average overall activity is supplemented with statistical estimations of the amplitudes of GIC fluctuations is suggested.

  14. Electromagnetic pulse research on electric power systems: Program summary and recommendations. Power Systems Technology Program

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, P.R.; McConnell, B.W.; Van Dyke, J.W. [Oak Ridge National Lab., TN (United States); Tesche, F.M. [Tesche (F.M.), Dallas, TX (United States); Vance, E.F. [Vance (E.F.), Fort Worth, TX (United States)

    1993-01-01

    A single nuclear detonation several hundred kilometers above the central United States will subject much of the nation to a high-altitude electromagnetic pulse (BENT). This pulse consists of an intense steep-front, short-duration transient electromagnetic field, followed by a geomagnetic disturbance with tens of seconds duration. This latter environment is referred to as the magnetohydrodynamic electromagnetic pulse (NMENT). Both the early-time transient and the geomagnetic disturbance could impact the operation of the nation`s power systems. Since 1983, the US Department of Energy has been actively pursuing a research program to assess the potential impacts of one or more BENT events on the nation`s electric energy supply. This report summarizes the results of that program and provides recommendations for enhancing power system reliability under HENT conditions. A nominal HENP environment suitable for assessing geographically large systems was developed during the program and is briefly described in this report. This environment was used to provide a realistic indication of BEMP impacts on electric power systems. It was found that a single high-altitude burst, which could significantly disturb the geomagnetic field, may cause the interconnected power network to break up into utility islands with massive power failures in some areas. However, permanent damage would be isolated, and restoration should be possible within a few hours. Multiple bursts would likely increase the blackout areas, component failures, and restoration time. However, a long-term blackout of many months is unlikely because major power system components, such as transformers, are not likely to be damaged by the nominal HEND environment. Moreover, power system reliability, under both HENT and normal operating conditions, can be enhanced by simple, and often low cost, modifications to current utility practices.

  15. Electromagnetic pulse research on electric power systems: Program summary and recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, P.R.; McConnell, B.W.; Van Dyke, J.W. (Oak Ridge National Lab., TN (United States)); Tesche, F.M. (Tesche (F.M.), Dallas, TX (United States)); Vance, E.F. (Vance (E.F.), Fort Worth, TX (United States))

    1993-01-01

    A single nuclear detonation several hundred kilometers above the central United States will subject much of the nation to a high-altitude electromagnetic pulse (BENT). This pulse consists of an intense steep-front, short-duration transient electromagnetic field, followed by a geomagnetic disturbance with tens of seconds duration. This latter environment is referred to as the magnetohydrodynamic electromagnetic pulse (NMENT). Both the early-time transient and the geomagnetic disturbance could impact the operation of the nation's power systems. Since 1983, the US Department of Energy has been actively pursuing a research program to assess the potential impacts of one or more BENT events on the nation's electric energy supply. This report summarizes the results of that program and provides recommendations for enhancing power system reliability under HENT conditions. A nominal HENP environment suitable for assessing geographically large systems was developed during the program and is briefly described in this report. This environment was used to provide a realistic indication of BEMP impacts on electric power systems. It was found that a single high-altitude burst, which could significantly disturb the geomagnetic field, may cause the interconnected power network to break up into utility islands with massive power failures in some areas. However, permanent damage would be isolated, and restoration should be possible within a few hours. Multiple bursts would likely increase the blackout areas, component failures, and restoration time. However, a long-term blackout of many months is unlikely because major power system components, such as transformers, are not likely to be damaged by the nominal HEND environment. Moreover, power system reliability, under both HENT and normal operating conditions, can be enhanced by simple, and often low cost, modifications to current utility practices.

  16. Final Report: Assessment of Combined Heat and Power Premium Power Applications in California

    Energy Technology Data Exchange (ETDEWEB)

    Norwood, Zack; Lipman, Tim; Marnay, Chris; Kammen, Dan

    2008-09-30

    This report analyzes the current economic and environmental performance of combined heat and power (CHP) systems in power interruption intolerant commercial facilities. Through a series of three case studies, key trade-offs are analyzed with regard to the provision of black-out ridethrough capability with the CHP systems and the resutling ability to avoid the need for at least some diesel backup generator capacity located at the case study sites. Each of the selected sites currently have a CHP or combined heating, cooling, and power (CCHP) system in addition to diesel backup generators. In all cases the CHP/CCHP system have a small fraction of the electrical capacity of the diesel generators. Although none of the selected sites currently have the ability to run the CHP systems as emergency backup power, all could be retrofitted to provide this blackout ride-through capability, and new CHP systems can be installed with this capability. The following three sites/systems were used for this analysis: (1) Sierra Nevada Brewery - Using 1MW of installed Molten Carbonate Fuel Cells operating on a combination of digestor gas (from the beer brewing process) and natural gas, this facility can produce electricty and heat for the brewery and attached bottling plant. The major thermal load on-site is to keep the brewing tanks at appropriate temperatures. (2) NetApp Data Center - Using 1.125 MW of Hess Microgen natural gas fired reciprocating engine-generators, with exhaust gas and jacket water heat recovery attached to over 300 tons of of adsorption chillers, this combined cooling and power system provides electricity and cooling to a data center with a 1,200 kW peak electrical load. (3) Kaiser Permanente Hayward Hospital - With 180kW of Tecogen natural gas fired reciprocating engine-generators this CHP system generates steam for space heating, and hot water for a city hospital. For all sites, similar assumptions are made about the economic and technological constraints of the

  17. IAEA Completes Expert Mission to Kori 1 Nuclear Power Plant in the Republic of Korea

    International Nuclear Information System (INIS)

    Full text: An international team of nuclear safety experts led by the International Atomic Energy Agency (IAEA) has completed a review of safety practices at the Kori 1 Nuclear Power Plant (NPP) near Busan in the Republic of Korea. The IAEA assembled the team at the request of Korea Hydro and Nuclear Power Co., Ltd. (KHNP) following a station blackout event on 9 February 2012. The team - comprised of experts from Belgium, France, Sweden, United Kingdom and the IAEA - conducted its mission from 4 to 11 June 2012 under the leadership of the IAEA's Division of Nuclear Installation Safety. The expert mission applied the methodology of the IAEA's Operational Safety Review (OSART) missions and covered the areas of Management, Organization and Administration; Operations; Maintenance and Operating Experience. The conclusions of the review are based on the IAEA's Safety Standards, which are developed by the Agency to help nations improve their nuclear safety practices, which are the responsibility of every nation that undertakes nuclear-related activities. Throughout the review, the exchange of information between the experts and plant personnel was very open, professional and productive. Prior to the mission, Korea's Nuclear Safety and Security Commission completed an interim investigation, and it continues to perform additional investigations and technical reviews. The Commission identified corrective actions for the plant concerning reinforcing safety culture, emergency diesel generator reliability, configuration control and risk management during refueling outage, test and maintenance procedures and emergency action level declaration. The expert mission confirmed that some corrective actions have already been completed and others are in progress. The expert mission found the management and staff of Kori 1 NPP to be committed and working hard to complete all improvements. The root cause analysis of the event at Kori 1 NPP is still in progress and is expected to lead to

  18. Space debris proximity analysis in powered and orbital phases during satelitte launch

    Science.gov (United States)

    Bandyopadhyay, P.; Sharma, R.; Adimurthy, V.

    The need to protect a launch vehicle in its ascent phase as well as the payload upon injection in particular and to prevent generation of debris in general through collision has led to many recent developments in the methodologies of SPAce DEbris PROximity (SPADEPRO) analysis, which is required for COLlision Avoidance or COLA studies. SPADEPRO refers to assessment of collision risk between catalogued resident space objects and launch vehicle or satellite of interest. The detection of close approaches to satellites/launch vehicles during the launch and early post-deployment phase of their lifetimes is an important subset of the overall problem. Potential collisions during this period can usually be avoided by adjusting the time of launch within a specified launch window. In Ref- 1 a series of filters through which candidate objects have to pass before determining its close approach distances from either analytical propagators like SGP4/SDP4 or any numerical prediction package, has been described. Unfortunately, this detection technique cannot strictly be applied since assumption of orbital motion is violated when powered launch trajectories are considered. Ref- 2 has proposed an algorithm for determining launch window blackout intervals based on the avoidance of close approaches for trajectories, which are fixed relative to an Earth Centered Earth Fixed (ECEF) reference frame. In this paper, authors approximate the powered launch trajectory into a series of orbital trajectories so that those trajectories envelope the powered launch trajectory in position-velocity phase space. Following this, filters described in Ref- 1 have been utilized to find out potential candidates from resident space objects. In Ref- 2, 3 &4 the blackout period has been observed when the closest approach distance is below a certain threshold. Instead, in this paper authors use collision probability, considering dispersions in respective trajectories of resident space objects and launch vehicle

  19. Recertification Project Plan

    International Nuclear Information System (INIS)

    the Department of Energy (DOE) wishes to make significant changes to the WIPP disposal system, those changes must be reviewed and approved by the EPA prior to or following recertification, via the 'planned change' process. As a measure of plans to implement significant changes to the WIPP disposal system that were not included in the CCA prior to recertification, this plan includes a 'blackout period' during which the DOE will refrain from proposing significant changes to the EPA. This 'blackout period' is intended to allow the EPA sufficient time to act on the DOE's change requests prior to recertification, anticipating that a rule making will be required before the EPA can act on some change requests. The 'blackout period' will also allow the DOE sufficient time to prepare the recertification application after the EPA acts on the change requests. A third major principle woven into this plan commits the DOE to providing, as part of the CRA, the results of impact, performance, or compliance assessments that examine the combined effects of changes made to the disposal system since submission of the CCA. The end-result of the Recertification Project is intended to be a decision by the EPA to recertify the repository without interruptions in disposal operations. A critically important milestone as we move toward that end result will be the production and delivery to the EPA of the CRA. All institutional members of the WIPP family have an extremely heavy stake in timely and effective completion of the work outlined in this plan. We owe it to the nation to complete this effort in a manner that allows for unabated cleanup of defense-related transuranic (TRU) nuclear waste. Our belief and hope is that this effort will serve as an excellent model to be followed in future recertifications of the repository.

  20. Human Factors for Situation Assessment in Grid Operations

    Energy Technology Data Exchange (ETDEWEB)

    Guttromson, Ross T.; Schur, Anne; Greitzer, Frank L.; Paget, Mia L.

    2007-08-08

    Executive Summary Despite advances in technology, power system operators must assimilate overwhelming amounts of data to keep the grid operating. Analyses of recent blackouts have clearly demonstrated the need to enhance the operator’s situation awareness (SA). The long-term objective of this research is to integrate valuable technologies into the grid operator environment that support decision making under normal and abnormal operating conditions and remove non-technical barriers to enable the optimum use of these technologies by individuals working alone and as a team. More specifically, the research aims to identify methods and principles to increase SA of grid operators in the context of system conditions that are representative or common across many operating entities and develop operationally relevant experimental methods for studying technologies and operational practices which contribute to SA. With increasing complexity and interconnectivity of the grid, the scope and complexity of situation awareness have grown. New paradigms are needed to guide research and tool development aimed to enhance and improve operations. In reviewing related research, operating practices, systems, and tools, the present study established a taxonomy that provides a perspective on research and development surrounding power grid situation awareness and clarifies the field of human factors/SA for grid operations. Information sources that we used to identify critical factors underlying SA included interviews with experienced operational personnel, available historical summaries and transcripts of abnormal conditions and outages (e.g., the August 14, 2003 blackout), scientific literature, and operational policies/procedures and other documentation. Our analysis of August 2003 blackout transcripts and interviews adopted a different perspective than previous analyses of this material, and we complemented this analysis with additional interviews. Based on our analysis and a broad

  1. Basic Research Needs for Superconductivity. Report of the Basic Energy Sciences Workshop on Superconductivity, May 8-11, 2006

    Energy Technology Data Exchange (ETDEWEB)

    Sarrao, J.; Kwok, W-K; Bozovic, I.; Mazin, I.; Seamus, J. C.; Civale, L.; Christen, D.; Horwitz, J.; Kellogg, G.; Finnemore, D.; Crabtree, G.; Welp, U.; Ashton, C.; Herndon, B.; Shapard, L.; Nault, R. M.

    2006-05-11

    As an energy carrier, electricity has no rival with regard to its environmental cleanliness, flexibility in interfacing with multiple production sources and end uses, and efficiency of delivery. In fact, the electric power grid was named ?the greatest engineering achievement of the 20th century? by the National Academy of Engineering. This grid, a technological marvel ingeniously knitted together from local networks growing out from cities and rural centers, may be the biggest and most complex artificial system ever built. However, the growing demand for electricity will soon challenge the grid beyond its capability, compromising its reliability through voltage fluctuations that crash digital electronics, brownouts that disable industrial processes and harm electrical equipment, and power failures like the North American blackout in 2003 and subsequent blackouts in London, Scandinavia, and Italy in the same year. The North American blackout affected 50 million people and caused approximately $6 billion in economic damage over the four days of its duration. Superconductivity offers powerful new opportunities for restoring the reliability of the power grid and increasing its capacity and efficiency. Superconductors are capable of carrying current without loss, making the parts of the grid they replace dramatically more efficient. Superconducting wires carry up to five times the current carried by copper wires that have the same cross section, thereby providing ample capacity for future expansion while requiring no increase in the number of overhead access lines or underground conduits. Their use is especially attractive in urban areas, where replacing copper with superconductors in power-saturated underground conduits avoids expensive new underground construction. Superconducting transformers cut the volume, weight, and losses of conventional transformers by a factor of two and do not require the contaminating and flammable transformer oils that violate urban safety

  2. Lights of Democracy, Authority and Liberty-On the History of News Legal System in Burma over the Past 160 Years%开明、威权与自由之光--160年缅甸新闻法制史管窥

    Institute of Scientific and Technical Information of China (English)

    展江; 黄晶晶

    2013-01-01

    缅甸曾经是亚洲享有最充分的新闻自由的国家,但是到了20世纪中期以后,随着1962年军事政变,缅甸由一个亚洲较富裕国家变成了落后国家,新闻界则经历了长达半个世纪的新闻管制。2011年,缅甸开启民主化政治改革,新闻界也随之开始了改革之路。通过梳理缅甸历史上的新闻自由、二战后军政府对新闻的管制和媒体的抗争以及正在进行的政治新闻变革举措,可以揭示出一个当代威权主义国家刚刚开始的媒体和政治转型之路。%Burma used to be a country which enjoyed the freedom of press in Asia during the 19th century.However, after the military coup in 1962, the press in Burma experienced more than half a century of news blackout, drawing back from a rich country in Asia to a backward one.In 2011, due to the launching of the political and democratic reform, the press in Burma started its reforming process.This paper aims to discuss the history of news development in Burma, including the freedom of press in the past, the news blackout after the 2nd World War by the military government and the struggle of media, and the polit-ical, news reform at the moment.In this way, an authoritative nation with news and political change on its way is to be presen-ted.

  3. 核电厂辅助给水系统控制方案设计研究%Study on Control System of Auxiliary Feedwater System of Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    鲁超

    2015-01-01

    Auxiliary water supply system is an important system in the design of safety facilities of nuclear power station. The common cause fault of software and the power plant station blackout are two key factors for control system of ASG. So in the design of the control system, in order to deal with the two failure factors, the control strategy of diversity and emergency power supply are respectively adopted. Through analysis diversity control strategy is an effect method to prevent the failure of the safety functions resulting from software common cause failure which meets single failure criterion. In the case of station blackout, it is necessary to provide emergency power supply for control system of the starting ASG, and ensure the system safety functions workable.%辅助给水系统(ASG)是核电厂专设安全设施中重要的系统。对于实现对ASG功能控制的安全级系统,软件共因故障和全厂失电是导致控制失效的两个关键因素。因此,在进行控制系统设计时,为应对这两大失效因素,分别采用了多样性和增加应急电源的控制策略。通过分析,采用多样性控制策略可以有效地防止软件共因故障导致安全功能丧失的风险,保证系统满足单一故障的要求。同时在全厂断电的情况下,增加应急供电电源,对启动ASG功能的控制系统进行紧急供电,保证系统安全功能可执行。

  4. Demonstration of a Novel Synchrophasor-based Situational Awareness System: Wide Area Power System Visualization, On-line Event Replay and Early Warning of Grid Problems

    Energy Technology Data Exchange (ETDEWEB)

    Rosso, A.

    2012-12-31

    Since the large North Eastern power system blackout on August 14, 2003, U.S. electric utilities have spent lot of effort on preventing power system cascading outages. Two of the main causes of the August 14, 2003 blackout were inadequate situational awareness and inadequate operator training In addition to the enhancements of the infrastructure of the interconnected power systems, more research and development of advanced power system applications are required for improving the wide-area security monitoring, operation and planning in order to prevent large- scale cascading outages of interconnected power systems. It is critically important for improving the wide-area situation awareness of the operators or operational engineers and regional reliability coordinators of large interconnected systems. With the installation of large number of phasor measurement units (PMU) and the related communication infrastructure, it will be possible to improve the operators’ situation awareness and to quickly identify the sequence of events during a large system disturbance for the post-event analysis using the real-time or historical synchrophasor data. The purpose of this project was to develop and demonstrate a novel synchrophasor-based comprehensive situational awareness system for control centers of power transmission systems. The developed system named WASA (Wide Area Situation Awareness) is intended to improve situational awareness at control centers of the power system operators and regional reliability coordinators. It consists of following main software modules: • Wide-area visualizations of real-time frequency, voltage, and phase angle measurements and their contour displays for security monitoring. • Online detection and location of a major event (location, time, size, and type, such as generator or line outage). • Near-real-time event replay (in seconds) after a major event occurs. • Early warning of potential wide-area stability problems. The system has been

  5. Accidental Thawing of Embryos, Cryopreserved for Transfer. Two Italian cases, Milan and Rome.

    Science.gov (United States)

    Busardò, Francesco P; Vergallo, Gianluca Montanari; Turillazzi, Emanuela; Bolino, Giorgio; Vullo, Annamaria; Frati, Paola

    2016-01-01

    The bioethical and juridical debate on the status of frozen embryos sometimes adds new issues arising from new scientific evidence or by accidental occurrences that bring to the attention of the scientific community the need for new practical solutions. Within this scenario, there have been, in recent years, episodes concerning the accidental thawing of embryos, which have been cryopreserved for transfer. Two Italian cases (the Milan and the Rome cases) are here reported: the Milan case involves a couple undergoing artificial insemination. Three eggs were collected for insemination and two of them had been fertilized. During the night of 8/9 May 2007 a short circuit occurred, resulting in an electricity blackout, which caused the loss of the embryos in culture, which should have been transferred to the woman's uterus on 9 May. The couple applied for damage compensation from the hospital following the loss of the embryos. The case went to Court and the result was a judgment issued by the Milan civil court, which recognized that the centre was to blame for irreparable damage to the embryos. The Rome case, involves two couples (A and B) affected by sterility who applied to an authorized public centre to undergo an ART program. Following the medical procedures, two of the embryos produced were transferred to the woman in couple A and five were frozen, whereas three embryos produced by couple B were transferred to the uterus of the woman and six eggs were cryopreserved in the centre. Two years after the procedure there was an electricity blackout, and the backup electricity generator failed to function, causing the loss of the gametes and the embryos cryopreserved in the centre. Legal proceedings begun by the couples to obtain compensation for damages are still underway. The above reported cases have significantly intensified the bioethical debate on the lawfulness of such practices and on the fate of the cryopreserved embryos, at the same time opening new frontiers in

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-07-24

    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, encourage rapid voluntary reductions in demand, and provide incentives for actions that would result in load reductions. Three bills-Assembly Bill 970, Senate Bill X1 5 and Assembly Bill X1 29-allocated roughly $950 million for consumption and demand reduction programs. The governor also enacted a variety of additional measures, including the ''Flex Your Power'' (media awareness and direct business involvement) campaign, requirements for retail sector outdoor lighting reductions, and toughening of energy efficiency building codes. There were, in fact, significant reductions in electricity demand in California during the summer of 2001 and the large number of expected supply disruptions was avoided. To understand the nature of these demand reductions and the motivations for consumer response, Washington State University (WSU) undertook a study for the California Energy Commission (CEC) focusing on conservation behavior in the residential, commercial, and agricultural sectors. The research presented in this report represents an exploration of the response of commercial and institutional organizations to the California energy situation and the unique set of influences that existed during this time. These influences included informational messages and media attention, program interventions, price changes, and external triggering events (e.g., blackouts). To better understand the effects of these influences on organizational response to the energy situation, we

  7. Critical infrastructure: impacts of natural hazards and consequences

    Science.gov (United States)

    Petrova, Elena

    2014-05-01

    Critical infrastructure such as oil and gas pipelines, transmission facilities, heat-, and water supply, lines of communications, roads, railways as well as air and water transport play the key role in social and economic development of every country. Therefore, accidents causing failures and breakdowns of critical infrastructure facilities have the most drastic consequences for the society, economy, and environment. For example, road accidents cause the highest number of fatalities and injuries all over the world, especially in the middle-income countries. The so-called "blackouts" or accidental losses of electric power and power outages entail serious social troubles and heavy economic losses. The pipeline ruptures and oil-tanker crashes accompanied by oil releases cause the most severe environmental and large material damages. Critical infrastructure facilities are most vulnerable to the impacts of natural hazards that trigger many accidents in them especially in the regions most at natural risk. The Russian Federation has more than 2.6 million km of transmission facilities, 940,000 km of roads, 102,000 km of inland waterways, 86,000 km of railways, and more than 70,000 km of trunk pipelines. Many facilities are beyond of their service life and need reconstruction. A very high level of deterioration and "human factor" are the main cause of accidents, ruptures, and crashes. However, natural hazards and disasters also play an essential (sometimes a leading) role in triggering or magnifying accidents in these objects. Thus, natural factors cause more than 70 percent of all "blackouts", about 20 percent of accidents at heat- and water supply systems and water accidents, five percent of pipeline ruptures, and about two to three percent of air crashes, road, and railway accidents. The influence of natural factors is stronger in the North-Western and Central parts of the European Russia, in Krasnodarsky Territory (South of Russia) and in Far East that are more exposed

  8. Construction and Application of Power Grid Operation Risk Assessment and Rating System%电网运行风险评估与定级体系的构建及应用

    Institute of Scientific and Technical Information of China (English)

    王一枫; 汤伟; 刘路登; 郭创新

    2015-01-01

    To solve engineering application defects such as lack of assessment details and risk information in the risk index system,this paper presents a power grid operation risk assessment and rating system.Firstly,redefine the risk structure as a set of risk grade,risk kind,risk probability,risk severity,reason set and consequence set,while classifying risk categories as loss of load,overload,voltage deviation,grid splitting,blackout of plant/station,and blackout of important users.Secondly, design the rating method of risk probability grade,risk severity grade and risk grade.Finally,divide the system flow into five parts as information collection,risk identification,risk assessment,risk rating and risk warning,and illustrate the system application effects in Dispatch and Control Center of State Grid Anhui Electric Power Company.%为解决风险指标体系在工程应用中存在的评估细节反映不足和风险信息不够充分的缺陷,文中提出了一种电网运行风险评估与定级体系。首先,在结构上将风险重新定义为等级、类别、概率、严重程度、原因集和后果集的集合,在类别上将风险分为减供负荷、重载或过载、电压偏移、电网解列、厂站全停和重要用户全停。其次,设计了各类风险发生概率等级、严重程度等级及风险综合等级的定级方法。最后,从信息采集、风险辨识、风险评估、风险定级和风险预警五个环节设计了体系流程,并对该体系的应用效果作了说明。

  9. Research on Improving GPS Communication Performance in Near Space by Additional Magnetic Field%外加磁场改善临近空间GP S通信研究

    Institute of Scientific and Technical Information of China (English)

    周天翔; 陈长兴; 蒋金; 任晓岳; 胡明睿

    2016-01-01

    针对飞行器以高超声速穿过临近空间大气层产生的通信“黑障”问题,提出了外加磁场,改变电磁环境以解决通信黑障问题的方案。依据美国RAM C 提供的飞行试验数据,建立磁化等离子体鞘套模型,通过数值计算方法分析了磁场强度、等离子体厚度、等离子体碰撞频率和等离子体电子密度对 GPS 信号传输的反射和衰减特性。综合分析仿真表明:对处于低频段的GPS信号,通过在航天器周围添加磁场,能够明显改善电磁波在等离子体鞘套中的传输性能,当外加磁场强度大于2 T时,GPS信号在等离子体鞘套中的传输衰减值均在5 dB以下,有效减缓了黑障对于电磁波传输的影响,达到了较好的通信状态。%Aimed at the communication blackout problem that a hypersonic aircraft passes through near space atmosphere,a method that an additional magnetic field is used to change electromagnetic environ-ments of plasma sheath is proposed.According to the data provided by radio attenuation measurement C (RAM C)voyage experiment,a model of plasma sheath is established.This paper analyzes the magnetic field intensity and parameters of plasma including plasma thickness,plasma density,plasma collision fre-quency to get the reflection and attenuation properties of GPS wave propagation in plasma sheath by nu-merical calculation.Comprehensive analysis shows that additional the magnetic field around aircraft can ef-fectively solve the"communication blackout"problem especially directed against GPS signal in low fre-quency.When magnetic field intensity is over 2 T,the transmission attenuation values of GPS signal in plasma sheath are all 5 dB below.The communication state is perfect.

  10. Dynamic Analysis of Diesel Generator System after Loss of Offsite Power Event Occurring in Nuclear Power Plants%核电厂丧失厂外电源事件下柴油发电机系统动态响应分析

    Institute of Scientific and Technical Information of China (English)

    李哲

    2012-01-01

    将系统可靠性分析方法GO法与Markov法相结合,对核电厂概率安全分析(PSA)中厂外电源丧失(LOOP)后柴油发电机应急响应系统在24h内缓解全厂断电(SBO)事件中的动态过程进行分析,解决了维修相关存在下可修系统可靠性精确计算问题,并通过创建GO法“备用门”操作符真实地模拟应急响应系统工作的逻辑关系.通过将2种可靠性分析方法相结合使用的尝试,使之与柴油发电机应急响应系统存在维修相关的实际情况相适应,拓展了2种方法的分析领域,同时能够更为精确地得出SBO对系统安全运行的影响.%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.

  11. The potential for distributed generation in Japanese prototype buildings: A DER-CAM analysis of policy, tariff design, building energy use, and technology development (Japanese translation)

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nan; Marnay, Chris; Firestone, Ryan; Gao, Weijun; Nishida, Masaru

    2004-10-15

    The August 2003 blackout of the northeastern U.S. and CANADA caused great economic losses and inconvenience to New York City and other affected areas. The blackout was a warning to the rest of the world that the ability of conventional power systems to meet growing electricity demand is questionable. Failure of large power systems can lead to serious emergencies. Introduction of on-site generation, renewable energy such as solar and wind power and the effective utilization of exhaust heat is needed, to meet the growing energy demands of the residential and commercial sectors. Additional benefit can be achieved by integrating these distributed technologies into distributed energy resource (DER) systems. This work demonstrates a method for choosing and designing economically optimal DER systems. An additional purpose of this research is to establish a database of energy tariffs, DER technology cost and performance characteristics, and building energy consumption for Japan. This research builds on prior DER studies at the Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) and with their associates in the Consortium for Electric Reliability Technology Solutions (CERTS) and operation, including the development of the microgrid concept, and the DER selection optimization program, the Distributed Energy Resources Customer Adoption Model (DER-CAM). DER-CAM is a tool designed to find the optimal combination of installed equipment and an idealized operating schedule to minimize a site's energy bills, given performance and cost data on available DER technologies, utility tariffs, and site electrical and thermal loads over a test period, usually an historic year. Since hourly electric and thermal energy data are rarely available, they are typically developed by building simulation for each of six end use loads used to model the building: electric-only loads, space heating, space cooling, refrigeration, water heating, and natural-gas-only loads. DER-CAM provides a

  12. Thermal-hydraulic analysis on Ex-Vessel fuel Storage Tank of MONJU at severe accident

    International Nuclear Information System (INIS)

    In this paper, results of a thermal-hydraulic analysis on the Ex-Vessel fuel Storage Tank (EVST) of the fast breeder reactor MONJU at severe accident is described. Safety evaluations on this facility have ever been performed by using a one-dimensional flow network code. However, validation on a model of this code has been needed, because EVST has plenums and asymmetry equipment. Therefore we performed a CFD analysis under a condition of station blackout (SBO) in order to clarify the circulation flow rate and multidimensionality of the EVST. As a result, the following points were confirmed: 1) Circulation flow rate is maintained half of a flow rate at the rated operation condition at the minimum. 2) Thermal stratification arises in the lower plenum at SBO. 3) Circumferential distribution of flow rate at the lower plenum is made uniform at the inlet of the rotating rack. 4) Thermal-hydraulic behavior in the rotating rack is almost one-dimensional. (author)

  13. A study on the mitigating capability of an auxiliary feedwater system during SBO for APR1400

    International Nuclear Information System (INIS)

    The objective of this paper is to establish an auxiliary feedwater (AFW) operational technical bases for the Korean Next Generation Reactor (APR1400) by modeling the plant, and by analyzing station blackout (SBO) using the MELCOR code. For the integrity of the reactor vessel and containment safety against severe accidents, it is essential to understand the severe accident sequences and to assess accident progression accurately using computer codes. Furthermore, it is important to attain the capability to analyze the advanced nuclear reactor design for the severe accident prevention and mitigation. Accident analyses are also undertaken to find out how effective AFW is mitigating in severe accident progresses. A nominal base case for SBO without AFW, time interval between feedwater stop and reactor vessel failure is 12,740 seconds. When AFW operates to mitigate the SBO accident progression 2, 4 and 8 hours after SBO starts, the reactor vessel failure is delayed for 20,415 seconds, 22,633 seconds and 26,508 seconds, respectively thus the operator has more time available for AC recovery and accident mitigation to prevent reactor vessel failure. (author)

  14. Shining India?: Assessing and addressing the risks from an unsustainable trajectory of climate, water, food, energy and income inequity

    Science.gov (United States)

    Lall, U.

    2012-12-01

    Climate and demographics are primary drivers of regional resource sustainability. In today's global economy, increasing trade has provided a mechanism to alleviate regional stresses. However, increasing regional income promotes consumption, aggravating regional and global resource pressures. South Asia, has the highest population density at a sub-continent scale. Given its monsoonal climate, and high intensity of agriculture it faces perhaps the most severe population weighted water stress in the world. Rapidly declining groundwater tables and the associated high energy use for pumping for irrigated agriculture translate into unsustainable energy imports and expenditure that contributed to the two largest blackouts in global history in summer 2012. Access to water has been progressively declining for both rural and urban populations for the last 3 decades. The increasing energy imports and poor grid reliability translate into limits to the growth of manufacturing and exports of goods and services. The growing income inequity within the population and across national borders, and the impacts of floods and droughts on access to water, food and energy collectively suggest a very high risk for social unrest and a conflict flashpoint. I present a scenario analysis that establishes this case for the emergence of internal and external strife in the region as an outcome of the current resource and natural disaster management policies in the region. Prospects for strategic policy changes for water and energy management and the design of a food procurement and distribution system that could lead to a better future are discussed.

  15. Atucha-I source terms for sequences initiated by transients

    International Nuclear Information System (INIS)

    The present work is part of an expected source terms study in the Atucha I nuclear power plant during severe accidents. From the accident sequences with a significant probability to produce core damage, those initiated by operational transients have been identified as the most relevant. These sequences have some common characteristics, in the sense that all of them resume in the opening of the primary system safety valves, and leave this path open for the coolant loss. In the case these sequences continue as severe accidents, the same path will be used for the release of the radionuclides, from the core, through the primary system and to the containment. Later in the severe accident sequence, the failure of the pressure vessel will occur, and the corium will fall inside the reactor cavity, interacting with the concrete. During these processes, more radioactive products will be released inside the containment. In the present work the severe accident simulation initiated by a blackout is performed, from the point of view of the phenomenology of the behavior of the radioactive products, as they are transported in the piping, during the core-concrete interactions, and inside the containment buildings until it failure. The final result is the source term into the atmosphere. (author)

  16. Visual and proprioceptive contributions to postural control of upright stance in unilateral vestibulopathy.

    Science.gov (United States)

    Eysel-Gosepath, Katrin; McCrum, Christopher; Epro, Gaspar; Brüggemann, Gert-Peter; Karamanidis, Kiros

    2016-06-01

    Preserving upright stance requires central integration of the sensory systems and appropriate motor output from the neuromuscular system to keep the centre of pressure (COP) within the base of support. Unilateral peripheral vestibular disorder (UPVD) causes diminished stance stability. The aim of this study was to determine the limits of stability and to examine the contribution of multiple sensory systems to upright standing in UPVD patients and healthy subjects. We hypothesized that closure of the eyes and Achilles tendon vibration during upright stance will augment the postural sway in UPVD patients more than in healthy subjects. Seventeen UPVD patients and 17 healthy subjects performed six tasks on a force plate: forwards and backwards leaning, to determine limits of stability, and upright standing with and without Achilles tendon vibration, each with eyes open and closed (with blackout glasses). The COP displacement of the patients was significantly greater in the vibration tasks than the controls and came closer to the posterior base of support boundary than the controls in all tasks. Achilles tendon vibration led to a distinctly more backward sway in both subject groups. Five of the patients could not complete the eyes closed with vibration task. Due to the greater reduction in stance stability when the proprioceptive, compared with the visual, sensory system was disturbed, we suggest that proprioception may be more important for maintaining upright stance than vision. UPVD patients, in particular, showed more difficulty in controlling postural stability in the posterior direction with visual and proprioceptive sensory disturbance.

  17. Utilization of Telecom Technologies for the Disaster Management in Underdeveloped Coastal Districts of Pakistan

    Directory of Open Access Journals (Sweden)

    Wasim Shahid Khawaja

    2013-10-01

    Full Text Available Information and communication technologies plays critical role in all phases of disaster management, and enabler of e-services delivery to the underdeveloped areas. Unfortunately this critical infrastructure is highly prone to disasters. This paper is based on coastal areas of Pakistan, which were badly affected during floods 2005 -2012. Universal Service Fund (USF Pakistan has started many telecom projects for broadband infrastructure, telemedicine and distant learning to uplift the livelihood of underdeveloped areas. The telecom infrastructure collapsed during disasters and population sustained heavy damages due to unavailability of disaster information. Causes of breakdown of telecom infrastructure are investigated. Remedial options are found from literature review, public’s reports & case studies. Then, these technological options are applied upon Pakistan regulatory & telecom infrastructure context and two separate plans for survival of narrowband and broadband communication are proposed. Another contingency plan for easy deployable temporary infrastructure is given for the case of total blackout of communication. An overview of existing information & communication systems weaknesses & gaps are given, its remedies are discussed for the effective mitigation of disasters. This study can be extended to other underdeveloped regions of the world to serve the calamity struck regions with fewer economic and human losses.

  18. RSM modelling of an ATWS accident simulated by the ALMOD code: methodological and practical achievement

    International Nuclear Information System (INIS)

    A simulation study of a PWR station black-out ATWS has been performed by applying Response Surface Methodology (RSM) on the data obtained by inspecting the ALMOD code. The case under study has shown that the a priori information which alone could be inadequate, is optimally utilized if coupled with a preliminary sensitivity analysis through RSM techniques. In particular the engineering selection of the model variables and the rank order of the remaining ones had to be modified after an RSM preliminary sensitivity analysis. An other qualifying feature of the exercise is the use of randomization of the variables not included in the model in order to coherently exploit the methodology in its full efficiency. This procedure is able to give a figure of merit of the global importance of the neglected variables through the analysis of residuals. Results show that the proposed technique is an effective tool for selecting the most important accident variables and that the body of information gained is significant with respect to the number of observations performed

  19. AP1000{sup R} severe accident features and post-Fukushima considerations

    Energy Technology Data Exchange (ETDEWEB)

    Scobel, J. H.; Schulz, T. L.; Williams, M. G. [Westinghouse Electric Company, LLC, 1000 Westinghouse Dr., Cranberry Township, PA 16066 (United States)

    2012-07-01

    The AP1000{sup R} passive nuclear power plant is uniquely equipped to withstand an extended station blackout scenario such as the events following the earthquake and tsunami at Fukushima without compromising core and containment integrity. The AP1000 plant shuts down the reactor, cools the core, containment and spent fuel pool for more than 3 days using passive systems that do not require AC or DC power or operator actions. Following this passive coping period, minimal operator actions are needed to extend the operation of the passive features to 7 days using installed equipment. To provide defense-in-depth for design extension conditions, the AP1000 plant has engineered features that mitigate the effects of core damage. Engineered features retain damaged core debris within the reactor vessel as a key feature. Other aspects of the design protect containment integrity during severe accidents, including unique features of the AP1000 design relative to passive containment cooling with water and air, and hydrogen management. (authors)

  20. Heat Transfer Analysis of the Passive Residual Heat Removal Heat Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenwen; Tian, Wenxi; Su, Guanghui; Qiu, Suizheng [Jiaotong University, Shaanxi (China)

    2014-08-15

    In the present study, thermal-hydraulics characteristics of AP1000 passive residual heat removal heat exchanger (PRHR-HX) at initial operating stage were analyzed based on the porous media models. The data predicated by RELAP5 under the condition of the station blackout was employed as the inlet flow rate and temperature boundary of CFD calculation. The heat transfer from the primary side coolant to the in-containment refueling water storage tank (IRWST) side fluid was calculated in a three-dimensional geometry during iterations, and the distributed resistances were added into the C-type tube bundle regions. Three-dimensional distributions of velocity and temperature in the IRWST were calculated by the CFD code ANSYS FLUENT. The primary temperature, heat transfer coefficients of two sides and the heat transfer were obtained using the coupled heat transfer between the primary side and the IRWST side. The simulation results indicated that the water temperature rises gradually which leads to a thermal stratification phenomenon in the tank and the heat transfer capability decreases with an increase of water temperature. The present results indicated that the method containing coupled heat transfer from the primary side fluid to IRWST side fluid and porous media model is a suitable approach to study the transient thermal-hydraulics of PRHR/IRWST.

  1. See No Evil Write No Evil: Sexual Deviance In African Literature During Colonialism

    Directory of Open Access Journals (Sweden)

    Wazha Lopang

    2014-10-01

    Full Text Available This paper argues that writers of African literature during colonialism differed in their portrayal of sexuality, particularly that which was considered deviant by nature, because of their need to build an ‘upright’ African image, no matter how artificial this was. The paper looks at how the political environment dictated sexual expression amongst characters and that the urban setting was more candid in its narrative style. There was also a total blackout on homosexuality between characters and where this took place, it was presented as something that was alien to the African culture in general and to the personality in particular. Writers who depicted pre-colonial settings limited sexuality to procreation and as a comment to the African’s link with the ancestors. There is also a correlation between the geographic location of texts and the degree of sexual expression that the writer engages in. As such the paper argues that sexual deviance is depicted as a matter of geography over and above thematic concerns.

  2. 电力用油溶解气体色谱分析与应用%Electricity Oil Dissolved Gas Chromatographic Analysis and Application

    Institute of Scientific and Technical Information of China (English)

    罗文

    2014-01-01

    分析油中溶解气体的含量能预测设备的内部故障,从而防止设备损坏和可能引起的电网大面积停电事故。利用绝缘油中溶解气体色谱分析技术,并结合其他试验手段可随时监视设备的运行状况,这对保障设备甚至电网安全运行可起到积极作用。通过分析主变油中溶解气体的色谱,发现了其内部存在的潜伏性故障。%The content of dissolved gases in oil can predict the internal failure of equipment, so as to prevent equipment damage and power blackouts that may arise. The use of insulating oil dissolved gas chromatography analysis technique, combined with other test instruments can always monitor the operational status of equipment, which guarantee the safe operation of equipment and even power can play a positive role. By analyzing the main transformer oil dissolved gas chromatography and found the existence of internal latent failures.

  3. Thermal hydraulic issues of containment filtered venting system for a long operating time

    Energy Technology Data Exchange (ETDEWEB)

    Na, Young Su; Ha, Kwang Soon; Park, Rae Joon; Park, Jong Hwa [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Song Won [Nuclear Safety Evaluation, Daejeon (Korea, Republic of)

    2014-12-15

    This study investigated the thermal hydraulic issues in the Containment Filtered Venting System (CFVS) for a long operating time using the MELCOR computer code. The modeling of the CFVS, including the models for pool scrubbing and the filter, was added to the input file for the OPR-1000, and a Station Blackout (SBO) was chosen as an accident scenario. Although depressurization in the containment building as a primary objective of the CFVS was successful, the decontamination feature by scrubbing and filtering in the CFVS for a long operating time could fail by the continuous evaporation of the scrubbing solution. After the operation of the CFVS, the atmosphere temperature in the CFVS became slightly above the water saturation temperature owing to the release of an amount of steam with high temperature from the containment building to the scrubbing solution. Reduced pipe diameters at the inlet and outlet of the CFVS vessel mitigated the evaporation of scrubbing water by controlling the amount of high-temperature steam and the water saturation temperature.

  4. Awareness On Microgrids And Various Protection Issues To Overcome In It

    Directory of Open Access Journals (Sweden)

    Rachna Verma

    2015-05-01

    Full Text Available ABSTRACT As we know India faces problem of Power blackout every year due to the overloading on the main electrical grid. To avoid the above problem Microgrids are the best solution. Basically Microgrids are the small version of electrical grid. They are independent power system. Microgrids can be connected with renewable energy sources such as solar and wind. The use of renewable energy introduces the need of various storing devices and supplies it whenever required. Microgrids can provide wide range of applications in buildings military camps and corporateacademic campuses etc. They can have efficient and effective provision of electricity to off-grid areas as well as keep the lights on in times of crisis for critical applications like hospital. Though Microgrids being so advantageous it has several technical challenging issues to overcome i.e. voltage and frequency control islanding and its protection in Microgrids. This paper discusses the overview of Microgrids and issue to overcome in it-its Protection.

  5. Assessing Short-Term Voltage Stability of Electric Power Systems by a Hierarchical Intelligent System.

    Science.gov (United States)

    Xu, Yan; Zhang, Rui; Zhao, Junhua; Dong, Zhao Yang; Wang, Dianhui; Yang, Hongming; Wong, Kit Po

    2016-08-01

    In the smart grid paradigm, growing integration of large-scale intermittent renewable energies has introduced significant uncertainties to the operations of an electric power system. This makes real-time dynamic security assessment (DSA) a necessity to enable enhanced situational-awareness against the risk of blackouts. Conventional DSA methods are mainly based on the time-domain simulation, which are insufficiently fast and knowledge-poor. In recent years, the intelligent system (IS) strategy has been identified as a promising approach to facilitate real-time DSA. While previous works mainly concentrate on the rotor angle stability, this paper focuses on another yet increasingly important dynamic insecurity phenomenon-the short-term voltage instability, which involves fast and complex load dynamics. The problem is modeled as a classification subproblem for transient voltage collapse and a prediction subproblem for unacceptable dynamic voltage deviation. A hierarchical IS is developed to address the two subproblems sequentially. The IS is based on ensemble learning of random-weights neural networks and is implemented in an offline training, a real-time application, and an online updating pattern. The simulation results on the New England 39-bus system verify its superiority in both learning speed and accuracy over some state-of-the-art learning algorithms.

  6. Transparency in the dark : an assessment of the Cameroonian electricity sector reform

    International Nuclear Information System (INIS)

    This paper documented the electricity reform process in Cameroon which, like many sub-Saharan countries, was under pressure to sell its public utilities. In 2001, AES Corporation, as a sole bidder, purchased Sonel, the state-owned Cameroonian electricity company. Since then, consumers have been faced with regular blackouts and tariff increases. Although some investment has been made in new generation capacity, the country's productivity decreased due to deterioration in the quality of electricity service. The paper identified many issues responsible for Cameroon's electricity problems. These include policy incoherence and lack of historical evidence supporting full-scale privatization. The author assessed the reform from a general set of criteria and developed a general framework to help understand what type of electricity market reforms are desirable in Cameroon and other sub-Saharan countries. This paper demonstrated that due to the weak institutions in Cameroon, competition and private ownership cannot be fully relied on. Recommendations were proposed to move beyond the many failures of privatization. It was suggested that transparency should be monitored by some independent international body when local institutions cannot do so. It was also noted that other countries can learn from the Cameroonian experience. refs., tabs., figs

  7. Secure and Efficient Electricity Supply. During the Transition to Low Carbon Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    Electricity shortages can paralyse our modern economies. All governments fear rolling black-outs and their economic consequences, especially in economies increasingly based on digital technologies. Over the last two decades, the development of markets for power has produced cost reduction, technological innovation, increased cross border trade and assured a steady supply of electricity. Now, IEA countries face the challenge of maintaining security of electricity supply during the transition to low-carbon economies. Low-carbon policies are pushing electricity markets into novel territories at a time when most of the generation and network capacity will have to be replaced. Most notably, wind and solar generation, now an integral part of electricity markets, can present new operating and investment challenges for generation, networks and the regional integration of electricity markets. In addition, the resilience of power systems facing more frequent natural disasters is also of increasing concern. IEA Ministers mandated the Secretariat to work on the Electricity Security Action Plan (ESAP), expanding to electricity the energy security mission of the IEA. This paper outlines the key conclusions and policy recommendations to ''keep the lights on'' while reducing CO2 emissions and increasing the efficiency.

  8. Crisis management and recovery from the damage to the laboratory animal production facility due to the Great East Japan Earthquake.

    Science.gov (United States)

    Ikeda, Takuya

    2012-01-01

    Charles River Laboratories Japan produces laboratory animals, mainly mice and rats. In its history, we have experienced many crises such as mass food poisoning of staff and contamination of animals. However, we overcame these crises, accomplishing our corporate missions to secure steady supply of healthy animals. Under such circumstances, in 2008, we faced an unprecedented crisis involving a novel influenza possibly becoming pandemic. Therefore, we prepared a Crisis Management Plan (CMP) and Business Continuity Plan (BCP) to avoid the worst case scenario. Fortunately, the novel influenza did not develop into a pandemic and no major problems occurred in production of our laboratory animals. In March 2011, our Tsukuba Breeding Center was struck by the Great East Japan Earthquake. Many cages fell from racks, and consequently, 14,000 mice and rats were euthanized. Moreover, this animal production facility experienced not only blackouts and water outage but also various maintenance problems. After triage of the animals, almost half of the animals kept were eventually lost. However, we recovered and resumed shipment of animals two weeks after the disaster by utilizing the CMP and BCP we initially created as a countermeasure against novel influenza. After two months, our production volume returned to normal except for two strains. I sincerely hope this review, which highlights our experience and related issues, will be a useful resource in regard to crisis management for people who are engaged in laboratory animal care and use. PMID:22293667

  9. Nature's third cycle a story of sunspots

    CERN Document Server

    Choudhuri, Arnab Rai

    2015-01-01

    The cycle of day and night and the cycle of seasons are two familiar natural cycles around which many human activities are organized. But is there a third natural cycle of importance for us humans? On 13 March 1989, six million people in Canada went without electricity for many hours: a large explosion on the sun was discovered as the cause of this blackout. Such explosions occur above sunspots, dark features on the surface of the Sun that have been observed through telescopes since the time of Galileo. The number of sunspots has been found to wax and wane over a period of 11 years. Although this cycle was discovered less than two centuries ago, it is becoming increasingly important for us as human society becomes more dependent on technology. For nearly a century after its discovery, the cause of the sunspot cycle remained completely shrouded in mystery. The 1908 discovery of strong magnetic fields in sunspots made it clear that the 11-year cycle is the magnetic cycle of the sun. It is only during the last ...

  10. Did Geomagnetic Activity Challenge Electric Power Reliability During Solar Cycle 23? Evidence from the PJM Regional Transmission Organization in North America

    Science.gov (United States)

    Forbes, Kevin F.; Cyr, Chris St

    2012-01-01

    During solar cycle 22, a very intense geomagnetic storm on 13 March 1989 contributed to the collapse of the Hydro-Quebec power system in Canada. This event clearly demonstrated that geomagnetic storms have the potential to lead to blackouts. This paper addresses whether geomagnetic activity challenged power system reliability during solar cycle 23. Operations by PJM Interconnection, LLC (hereafter PJM), a regional transmission organization in North America, are examined over the period 1 April 2002 through 30 April 2004. During this time PJM coordinated the movement of wholesale electricity in all or parts of Delaware, Maryland, New Jersey, Ohio, Pennsylvania, Virginia, West Virginia, and the District of Columbia in the United States. We examine the relationship between a proxy of geomagnetically induced currents (GICs) and a metric of challenged reliability. In this study, GICs are proxied using magnetometer data from a geomagnetic observatory located just outside the PJM control area. The metric of challenged reliability is the incidence of out-of-economic-merit order dispatching due to adverse reactive power conditions. The statistical methods employed make it possible to disentangle the effects of GICs on power system operations from purely terrestrial factors. The results of the analysis indicate that geomagnetic activity can significantly increase the likelihood that the system operator will dispatch generating units based on system stability considerations rather than economic merit.

  11. Policy changes and the dynamics of capacity expansion in the Swiss electricity market

    International Nuclear Information System (INIS)

    Capacity of supply is a crucial matter in electricity markets as it directly influences reliability of supply, price volatility and blackout risk. In this paper, we analyse the dynamics of capacity expansion in the Swiss electricity market and the impact of different policies such as nuclear phaseout and management of electricity exchanges - imports and exports - policies. This article develops the conceptualization model presented in [Ochoa, P., 2007b. Policy changes in the Swiss electricity market: a system dynamics analysis of likely market responses. Socio-Economic Planning Sciences 41 (4):336-349.]. We build a system dynamics model based on the dynamics of capacity expansion explained in the latter paper and present and analyse different scenarios. We conclude that international electricity exchanges are important for the Swiss market as they help to lower costs and to increase the income of the utility companies; however, we illustrate the need for explicit policies for managing imports and exports of electricity to avoid import dependence from neighbouring countries.

  12. Assessment of impact of a severe accident at nuclear power plant of Angra dos Reis with release of radionuclides to the atmosphere

    International Nuclear Information System (INIS)

    This study had as purpose the assess the impact of a severe accident, and also analyze the dispersion of 131I in the atmosphere, so that, through concentrating and inhaling dose of the plume, were possible to verify if the results are in accordance with the indicated data by the Plan of Emergency of the CNAAA regarding the Impact Zone and Control. This exercise was performed with the aid of an atmospheric model and a dispersion where to atmospheric modeling we used the data coupling WRF / CALMET and of dispersion, CALPUFF. The suggested accident consists of a Station Blackout at Nuclear Power of Angra (Unit 1), where through the total core involvement, will release 100% of the 131I to the atmosphere. The value of the total activity in the nucleus to this radionuclide is 7.44 x 1017 Bq, that is relative on the sixth day of burning. This activity will be released through the chimney at a rate in Bq/s in the scenario of 12, 24, 48 and 72 hours of release. Applying the model in the proposed scenario, it is verified that the plume has concentrations of the order of 1020 Bq/m³ and dose of about 108 Sv whose value is beyond of the presented by Eletronuclear in your current emergency plan. (author)

  13. Present state of electric power business in United States and Europe

    International Nuclear Information System (INIS)

    This article reported present state of nuclear power and electric power business in United States and Europe after Fukushima Daiichi Accident. As for the trend of demand and supply of electric power and policy, the accident forced Germany possibly to proceed with phase-out of nuclear power, but France and United States to sustain nuclear power with no great change of energy policy at this moment. As for the trend of electric power market, there was not state in United States with liberalized retail market of electric power after rolling blackouts occurred in California State in the early 2000s. In Germany proceeding with renewable energy introduction, renewable electricity fed into the grid was paid for by the network operators at fixed tariffs and the costs passed on to electricity consumers were increasing. Renewable Portfolio Standards (RPS) in United States forced the state to introduction of renewable energy to some ratio, and Feed-in Tariff (FIT) introduced in EU in 1990s lead to introduction of a large amount of renewable electricity targeted in 2020. Huge amount of wind power introduction brought about several problems to solve such that excess electric power above domestic demand had bad effects on grids in neighboring region. Enforcement of power transmission lines was also needed with increase of maximum electric power as well as introduction of a large amount of renewable electricity. (T. Tanaka)

  14. Answer to the dynamic (fretting effect) and static (oxide) behavior of electric contact surfaces: based on a five-year infrared thermographic study

    Science.gov (United States)

    Paez-Leon, Cristobal D.; Patino, Antonio R.; Aguillon, Luis

    1991-03-01

    This paper describes the results of a five-year study carried out in 38 power substations (230, 115, 34.5 and 13.8 Kv), located in the Western power electric system of CADAFE (Venezuela's national Electric Utility). A total of 154 hot spots were found between 1980 and 1982, a time span considered a reliable source of information in connection with methodology, term and results. The distribution of hot spots found during those years was 77, 33 and 44. The reduction of the spot/substation parameter was found to be 4.1, 3.3 and 3.1, respectively. Every item detected could have been the cause of major interruptions, locally and regionally, or even the system's blackout. The methodology used to determine the major concentration of findings and their location on the equipment, followed the sequence of Pareto's Diagram and Ishikawa's Graphic. Based on the results of the study whose results are presented here, a lubricant and compound-aid connector for Al-Al and bimetallic electric connections was formulated, developed, manufactured, tested (at IREQ laboratories) and traded (CONECTECH CAC- 01). To date, the whole process represents 12 years of work. The connector's behavior and reliability are being tested throughout Venezuela's national electric system (responsible for the supply of around 50,000 Gwh/year) with the use of 12 Tons of CONECTECH CAC-01.

  15. Assessing Short-Term Voltage Stability of Electric Power Systems by a Hierarchical Intelligent System.

    Science.gov (United States)

    Xu, Yan; Zhang, Rui; Zhao, Junhua; Dong, Zhao Yang; Wang, Dianhui; Yang, Hongming; Wong, Kit Po

    2016-08-01

    In the smart grid paradigm, growing integration of large-scale intermittent renewable energies has introduced significant uncertainties to the operations of an electric power system. This makes real-time dynamic security assessment (DSA) a necessity to enable enhanced situational-awareness against the risk of blackouts. Conventional DSA methods are mainly based on the time-domain simulation, which are insufficiently fast and knowledge-poor. In recent years, the intelligent system (IS) strategy has been identified as a promising approach to facilitate real-time DSA. While previous works mainly concentrate on the rotor angle stability, this paper focuses on another yet increasingly important dynamic insecurity phenomenon-the short-term voltage instability, which involves fast and complex load dynamics. The problem is modeled as a classification subproblem for transient voltage collapse and a prediction subproblem for unacceptable dynamic voltage deviation. A hierarchical IS is developed to address the two subproblems sequentially. The IS is based on ensemble learning of random-weights neural networks and is implemented in an offline training, a real-time application, and an online updating pattern. The simulation results on the New England 39-bus system verify its superiority in both learning speed and accuracy over some state-of-the-art learning algorithms. PMID:26441430

  16. Monitoring the performance of Aux. Feedwater Pump using Smart Sensing Model

    Energy Technology Data Exchange (ETDEWEB)

    No, Young Gyu; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2015-10-15

    Many artificial intelligence (AI) techniques equipped with learning systems have recently been proposed to monitor sensors and components in NPPs. Therefore, the objective of this study is the development of an integrity evaluation method for safety critical components such as Aux. feedwater pump, high pressure safety injection (HPSI) pump, etc. using smart sensing models based on AI techniques. In this work, the smart sensing model is developed at first to predict the performance of Aux. feedwater pump by estimating flowrate using group method of data handing (GMDH) method. If the performance prediction is achieved by this feasibility study, the smart sensing model will be applied to development of the integrity evaluation method for safety critical components. Also, the proposed algorithm for the performance prediction is verified by comparison with the simulation data of the MARS code for station blackout (SBO) events. In this study, the smart sensing model for the prediction performance of Aux. feedwater pump has been developed. In order to develop the smart sensing model, the GMDH algorithm is employed. The GMDH algorithm is the way to find a function that can well express a dependent variable from independent variables. This method uses a data structure similar to that of multiple regression models. The proposed GMDH model can accurately predict the performance of Aux.

  17. Desiccant HVAC system driven by a micro-CHP: Experimental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Angrisani, Giovanni; Roselli, Carlo; Sasso, Maurizio [Universita degli Studi del Sannio, Dipartimento di Ingegneria, Piazza Roma 21, Benevento, 82100 (Italy); Minichiello, Francesco [Universita degli Studi di Napoli Federico II, DETEC, P.le Tecchio 80, Napoli, 80125 (Italy)

    2010-11-15

    In the Mediterranean area, there is increase in demand for summer cooling satisfied by electrically driven units in domestic and small commercial sectors; this involves electric peak loads and black-outs. Consequently, there is an increasing interest in small scale polygeneration systems fuelled by natural gas. In this paper, attention is paid to a test facility, located in Southern Italy, to carry out experimental analysis on a small scale polygeneration system based on a natural gas-fired Micro-CHP and a desiccant HVAC system. The MCHP provides thermal power, recovered from engine cooling and exhaust gas, for the regeneration of the desiccant wheel and electric power for the chiller, the auxiliaries and the external units (computers, lights, etc.). The HVAC system can also operate in traditional way, by interacting with electric grid and gas-fired boiler. An overview of the main experimental results is shown, considering both the desiccant wheel and the global polygeneration system. The experimental results confirm that the performances of the desiccant wheel are strongly influenced by outdoor thermal-hygrometric air properties and regeneration temperature. The polygeneration system guarantees primary energy savings up to 21.2% and greenhouse-gas emissions reductions up to 38.6% with respect to conventional HVAC systems based on separate energy ''production''. (author)

  18. Analysis of core damage frequency: Peach Bottom, Unit 2 internal events appendices

    Energy Technology Data Exchange (ETDEWEB)

    Kolaczkowski, A.M.; Cramond, W.R.; Sype, T.T.; Maloney, K.J.; Wheeler, T.A.; Daniel, S.L. (Science Applications International Corp., Albuquerque, NM (USA); Sandia National Labs., Albuquerque, NM (USA))

    1989-08-01

    This document contains the appendices for the accident sequence analysis of internally initiated events for the Peach Bottom, Unit 2 Nuclear Power Plant. This is one of the five plant analyses conducted as part of the NUREG-1150 effort for the Nuclear Regulatory Commission. The work performed and described here is an extensive reanalysis of that published in October 1986 as NUREG/CR-4550, Volume 4. It addresses comments from numerous reviewers and significant changes to the plant systems and procedures made since the first report. The uncertainty analysis and presentation of results are also much improved, and considerable effort was expended on an improved analysis of loss of offsite power. The content and detail of this report is directed toward PRA practitioners who need to know how the work was done and the details for use in further studies. The mean core damage frequency is 4.5E-6 with 5% and 95% uncertainty bounds of 3.5E-7 and 1.3E-5, respectively. Station blackout type accidents (loss of all ac power) contributed about 46% of the core damage frequency with Anticipated Transient Without Scram (ATWS) accidents contributing another 42%. The numerical results are driven by loss of offsite power, transients with the power conversion system initially available operator errors, and mechanical failure to scram. 13 refs., 345 figs., 171 tabs.

  19. Adaptive load forecasting of the Hellenic electric grid

    Institute of Scientific and Technical Information of China (English)

    S. Sp. PAPPAS; L. EKONOMOU; V. C. MOUSSAS; P. KARAMPELAS; S. K. KATSIKAS

    2008-01-01

    Designers are required to plan for future expansion and also to estimate the grid's future utilization. This means that an effective modeling and forecasting technique,which will use efficiently the information contained in the available data,is required,so that important data properties can be extracted and projected into the future. This study proposes an adaptive method based on the multi-model partitioning algorithm (MMPA),for short-term electricity load forecasting using real data. The grid's utilization is initially modeled using a multiplicative seasonal ARIMA (autoregressive integrated moving average) model. The proposed method uses past data to learn and model the normal periodic behavior of the electric grid. Either ARMA (autoregressive moving average) or state-space models can be used for the load pattern modeling. Load anomalies such as unexpected peaks that may appear during the summer or unexpected faults (blackouts) are also modeled. If the load pattern does not match the normal be-havior of the load,an anomaly is detected and,furthermore,when the pattern matches a known case of anomaly,the type of anomaly is identified. Real data were used and real cases were tested based on the measurement loads of the Hellenic Public Power Cooperation S.A.,Athens,Greece. The applied adaptive multi-model filtering algorithm identifies successfully both normal periodic behavior and any unusual activity of the electric grid. The performance of the proposed method is also compared to that produced by the ARIMA model.

  20. Final results of the XR2-1 BWR metallic melt relocation experiment

    International Nuclear Information System (INIS)

    This report documents the final results of the XR2-1 boiling water reactor (BWR) metallic melt relocation experiment, conducted at Sandia National Laboratories for the U.S. Nuclear Regulatory Commission. The objective of this experiment was to investigate the material relocation processes and relocation pathways in a dry BWR core following a severe nuclear reactor accident such as an unrecovered station blackout accident. The imposed test conditions (initial thermal state and the melt generation rates) simulated the conditions for the postulated accident scenario and the prototypic design of the lower core test section (in composition and in geometry) ensured that thermal masses and physical flow barriers were modeled adequately. The experiment has shown that, under dry core conditions, the metallic core materials that melt and drain from the upper core regions can drain from the core region entirely without formation of robust coherent blockages in the lower core. Temporary blockages that suspended pools of molten metal later melted, allowing the metals to continue draining downward. The test facility and instrumentation are described in detail. The test progression and results are presented and compared to MERIS code analyses. 6 refs., 55 figs., 4 tabs