PSA Analysis of Switch Port Disabled on DCS Layer 1

2021 ◽  
Author(s):  
Yang Luo ◽  
Deyi Liu ◽  
Shengjia Zou ◽  
Yong Cao
Keyword(s):  
Working Conditions ◽  
Nuclear Power ◽  
Implementation Process ◽  
Radioactive Material ◽  
Stable Operation ◽  
Unit Level ◽  
Control Functions ◽  
Safe State ◽  
The Disabled ◽  
Reactor Protection System

Abstract This paper first introduces the background, purpose and implementation process of SDP, and then analyzes the SDP based on the disabled fault of the switch port of DCS layer 1 in nuclear power plant. This DCS failure caused 14 ports between the room level switch and the unit level switch on the first floor of DCS to be disabled, resulting in partial interruption of communication between the room level switch and the unit level switch, resulting in abnormal connection between KIC/BUP and the first floor, and all KIC control functions and BUP in order to prevent the fluctuation of working conditions from introducing new disturbance to the control system, the unit has been maintaining stable operation. During the whole event, the reactor was in a safe state, the reactor protection system was available, the three barriers were complete, and no radioactive material was released. The influence of DCS failure on core safety is analyzed by SDP, and the conclusion is given.

Danube Field Excursion 1988: Tritium Content of River Water; Radioactivity of Danube Sediments

1990 ◽  
Vol 22 (5) ◽  
pp. 203-210 ◽  
Author(s):  
D. Rank ◽  
F. J. Maringer ◽  
W. Papesch ◽  
V. Rajner
Keyword(s):  
River Water ◽  
Bottom Sediments ◽  
Nuclear Power ◽  
Radioactive Material ◽  
Reactor Accident ◽  
Tritium Content ◽  
Fine Sediments ◽  
Fish Samples ◽  
Field Excursion

Water, sediment, and fish samples were collected during the Danube excursion 1988, within a coordinated sampling program of the Radiology Working Group of the “Internationale Arbeitsgemeinschaft Donauforschung ” (K.Hübel, Munich; I. Kurcz, Budapest; D.Rank, Vienna). The H-3 content of the river water and the radioactivity of the bottom sediments were measured at the BVFA Arsenal, Vienna. The determined H-3 content of the Danube water corresponds with the long-term trend in the H-3 content of the hydrosphere; the values lie in the range of 3 Bq/kg downstream from Belgrade, upstream from Belgrade they are about 4 Bq/kg. It was only in the waste water plume of the nuclear power station of Kozloduj that a slightly elevated H-3 value - 6 Bq/kg - was determined. The content of the sediments of artificial radionuclides was found, at the time of the Danube field excursion, to be almost exclusively due to the radioactive material released following the reactor accident at Chernobyl in April 1986 (mainly Cs-137 and Cs-134). As a consequence of the air currents and precipitation conditions prevailing at the time of the accident, the bottom sediments in the lower course of the Danube were less contaminated than those in the upper course. The fine sediments were found to contain over 3000 Bq/kg of Cs-137 in the upper course of the Danube.

The Failure Analysis and Processing of Digital Reactor Protection System

2013 ◽  
Author(s):  
Jun Zhao ◽  
Xing Zhou ◽  
Jin Hu ◽  
Yanling Yu
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Phase 1 ◽  
Protection System ◽  
Pressurized Water Reactor ◽  
Communication Failure ◽  
Pressurized Water ◽  
Power Failure ◽  
Self Test ◽  
Reactor Protection System

The Qinshan Nuclear Power Plant phase 1 unit (QNPP-1) has a power rating of 320 MWe generated by a pressurized water reactor that was designed and constructed by China National Nuclear Corporation (CNNC). The TELEPERM XS I&C system (TXS) is to be implemented to transform analog reactor protection system (RPS) in QNPP-1. The paper mainly describes the function, structure and characteristic of RPS in QNPP-1. It focuses on the outstanding features of digital I&C, such as strong online self-test capability, the degradation of the voting logic processing, interface improvements and CPU security. There are some typical failures during the operation of reactor protection system in QNPP-1. The way to analyze and process the failures is different from analog I&C. The paper summarizes typical failures of the digital RPS in the following types: CPU failure, communication failure, power failure, Input and output (IO) failure. It discusses the cause, risk and mainly processing points of typical failure, especially CPU and communication failures of the digital RPS. It is helpful for the maintenance of the system. The paper covers measures to improve the reliability of related components which has been put forward effective in Digital reactor protection system in QNPP-1. It will be valuable in nuclear community to improve the reliability of important components of nuclear power plants.

scholarly journals Settlement process of radioactive dust to the ground inferred from the atmospheric electric field measurement

2012 ◽  
Vol 30 (1) ◽  
pp. 49-56 ◽  
Author(s):  
M. Yamauchi ◽  
M. Takeda ◽  
M. Makino ◽  
T. Owada ◽  
I. Miyagi
Keyword(s):  
Electric Field ◽  
Nuclear Power ◽  
Potential Gradient ◽  
Radioactive Material ◽  
Strong Wind ◽  
Fair Weather ◽  
Large Area ◽  
Radiation Dose Rate ◽  
Radioactive Dust ◽  
Cloudy Weather

Abstract. Radioactive materials from the accident at Fukushima Dai-ichi nuclear power plant (FNPP) in March 2011 spread over a large area, increasing the atmospheric electric conductivity by their ionizing effect, and reducing the vertical (downward) component of the DC electric field near the ground, or potential gradient (PG). PG data at Kakioka, 150 km away from the FNPP, showed independent changes compared to the radiation dose rate, and a comparison of these data revealed the local dynamics of the radioactive dust. (1) The initial drop of the PG to almost zero during 14–15 March is most likely due to radioactive dust suspended in the air near the ground during cloudy weather. (2) An episode of PG increase to more than 50 V m−1 on 16 March is most likely due to the re-suspension of the radioactive dust from the surface and subsequent removal from Kakioka by the strong wind from the non-contaminated area. (3) Low but finite values of the PG during 16–20 March most likely reflect a reduced amount of radioactive material near the ground after the above wind transported away the majority of the suspended radioactive dust. (4) Very low values of the PG after substantial rain on 20–22 March most likely reflect settlement of the radioactive material by rain-induced fallout. (5) Temporal recovery of daily variations from the end of March to the middle of April with low nighttime fair-weather baseline PG most likely reflects re-suspension of the radioactive dust into the air from the ground and trees, and subsequent transport to the other region or fallout to the ground until late April. (6) Weakening of the daily variation and gradual recovery of the nighttime fair-weather baseline after mid-April suggests a complete settlement of the radioactive material to the ground with partial migration to the subsurface.

Design of the Communication Independence for ACPR1000 Nuclear Power Plant Digital Safety I&C System

2017 ◽  
Author(s):  
Sun Na ◽  
Shi Gui-lian ◽  
Xie Yi-qin ◽  
Li Gang ◽  
Jiang Guo-jin
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Communication Networks ◽  
Nuclear Power ◽  
Protection System ◽  
Plant Safety ◽  
Safety And Reliability ◽  
Digital Protection ◽  
Architecture And Design ◽  
Reactor Protection System

Communication independence is one of the key criteria of digital safety I&C system design. This paper mainly analyzes the requirements for communication independence in safety regulations and standards, and then introduces the architecture and design features, including communication failure processing measures, of communication networks of ACPR1000 nuclear power plant safety digital protection system based on FirmSys platform developed by CTEC. The communication design meets the regulations requirements and effectively improves the safety and reliability of the system, and it is successfully applied in reactor protection system (RPS) of Yang Jiang nuclear power plant unit 5&6. In addition this design can provide reference for communication designs of other NPPs and industries.

Environmental Conditions of the Work Organization for the Disabled People

2000 ◽  
Vol 44 (8) ◽  
pp. 70-70
Author(s):  
Ewa Górska
Keyword(s):  
Working Conditions ◽  
Environmental Conditions ◽  
Social Economic ◽  
Sense Of Self ◽  
Work Organization ◽  
Disabled People ◽  
The Disabled ◽  
The Individual ◽  
A Company

A disabled person in a company is affected by a number of various environmental conditions. Among these the most important are such as organizational, technical, social, economic and, finally, legal working conditions. The standard and quality of the just mentioned conditions determine significantly the way in which a disabled person performs the assigned tasks and duties in the company and it also helps to create the individual sense of self-fulfillment and work satisfaction. What is more, at the same time the level of environmental conditions influences directly work efficiency and profits of the company. It must be clearly stated that working conditions do not appear immediately and spontaneously - they need careful planning and modern organization. This research paper presents the environmental conditions and discusses a model design of the work organization for the disabled people.

Precautions at Fukushima That Would Have Suppressed the Accident Severity

2018 ◽  
Vol 4 (3) ◽  
Author(s):  
Kenji Iino ◽  
Ritsuo Yoshioka ◽  
Masao Fuchigami ◽  
Masayuki Nakao
Keyword(s):  
Nuclear Power ◽  
Cooling System ◽  
Water Injection ◽  
Reactor Core ◽  
Radioactive Material ◽  
Injection System ◽  
Tsunami Waves ◽  
Ac Power ◽  
Pressure Water ◽  
High Pressure Coolant

Abstract The Great East Japan Earthquake on Mar. 11, 2011 triggered huge tsunami waves that attacked Fukushima Daiichi Nuclear Power Plant (Fukushima-1). Units 1, 3, and 4 had hydrogen explosions. Units 1–3 had core meltdowns and released a large amount of radioactive material. Published investigation reports did not explain how the severity of the accident could have been prevented. We formed a study group to find: (A) Was the earthquake-induced huge tsunami predictable at Fukushima-1? (B) If it was predictable, what preparations at Fukushima-1 could have avoided the severity of the accident? Our conclusions were: (a) The tsunami that hit Fukushima-1 was predictable, and (b) the severity could have been avoided if the plant had prepared a set of equipment, and most of all, had exercised actions to take against such tsunami. Necessary preparation included: (1) a number of direct current (DC) batteries, (2) portable underwater pumps, (3) portable alternating current (AC) generators with sufficient gasoline supply, (4) high voltage AC power trucks, and (5) drills against extended loss of all electric power and seawater pumps. This set applied only to this specific accident. A thorough preparation would have added (6) portable compressors, (7) watertight modification to reactor core isolation cooling system (RCIC) and high pressure coolant injection system (HPCI) control and instrumentation, and (8) fire engines for alternate low pressure water injection. Item (5), i.e., to study plans and carry out exercises against the tsunami would have identified all other necessary preparations.

Marine Technology Nuclear Propulsion in High-Performance Cargo Vessels

2002 ◽  
Vol 39 (01) ◽  
pp. 1-11
Author(s):  
Julio A. Vergara ◽  
Chris B. McKesson
Keyword(s):  
Gas Turbine ◽  
High Speed ◽  
Nuclear Power ◽  
High Performance ◽  
Nuclear Reactor ◽  
Maritime Transportation ◽  
Stable Operation ◽  
Fuel Price ◽  
Nuclear Propulsion ◽  
Recent Developments

It has been about 40 years since nuclear-powered merchant ships were seriously discussed in the naval architecture community. But recent developments in commercial shipping include bigger, faster, and more powerful ships, where nuclear propulsion may be an option worth considering. The development of advanced ship designs opens an opportunity for high-speed maritime transportation that could create new markets and recover a fraction of the high value goods currently shipped only by air. One of the vessels being considered is FastShip, a large monohull ship that would require 250 MW in 5 gas turbine-waterjet units. An estimate of the operation cost of FastShip reveals that its success relies heavily, among other things, on the fuel price, a single factor that comprises more than one third of the total operating costs. The alternative, a nuclear FastShip, would save, per trip, almost 5000 tons of exposure to fuel price fluctuation, and about half of this savings would further be available for additional cargo and revenues. Nuclear power results in a more stable operation due to the relatively constant low price of nuclear fuel. The nuclear power option is suitable for high-power demand and long-haul applications and a reactor pack could be available within the decade. A candidate design would be the helium-cooled reactor, which has been revisited by several nuclear reactor design teams worldwide. For the FastShip a suggested plant would consist of two modular helium reactors, each one with two 50 MW helium turbines and compressors geared to waterjet pumps, plus a single 50 MW gas turbine. This vessel becomes more expensive to build but saves in fuel, and still provides margin for cost, weight and size optimization. This paper discusses general characteristics of a FastShip with such a nuclear power plant and also highlights the benefits, drawbacks, pending issues and further opportunities for nuclear-powered high-speed cargo ships.

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