scholarly journals The Effect of Tungstate and Ethanolamines Added in Tap Water on Corrosion Inhibition of Ductile Cast Iron Pipe for Nuclear Power Plants

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1597
Author(s):  
Butaek Lim ◽  
Kitae Kim ◽  
Hyunyoung Chang ◽  
Heungbae Park ◽  
Youngsik Kim
Keyword(s):  
Cast Iron ◽  
Fire Protection ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Tap Water ◽  
Ductile Cast Iron ◽  
Passivation Film ◽  
Fire Extinguishing ◽  
Immersion Corrosion

Cast iron is primarily used in buried piping to transport water in the fire protection system of nuclear power plants; ductile cast iron is generally used for domestic nuclear power plants. In general, the fluid used as fire-extinguishing water in such fire protection systems is tap water, and corrosion inhibitors are not currently added. In this study, the synergistic effect of an adsorption barrier (monoethanolamine) and oxidized film in an environment with a corrosion inhibitor (tungstate) is examined, and the corresponding passivation properties are presented. An immersion corrosion test and electrochemical test in tap water to which only tungstate was added showed suppression of corrosion compared to molybdate at the same concentration. The polarization resistance value of a passivation film in tap water mixed with monoethanolamine and tungstate showed better results than that of the molybdate control. A surface analysis in mixed addition tap water also demonstrated that oxygen ions were sufficiently distributed, including at some spheroidized graphite sites, when tungstate was added compared to molybdate. In addition, the amount of tungsten ions adsorbed on the surface was larger than that of molybdenum ions, and it was confirmed that tungsten ions were evenly distributed over the entire surface.

scholarly journals Modernization of Fire Extinguishing Installations at Ukrainian NPPs

2017 ◽  
pp. 56-62
Author(s):  
I. Rezvik ◽  
K. Yefimova ◽  
S. Polyvoda ◽  
V. Iokst
Keyword(s):  
Fire Protection ◽  
Fire Safety ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
International Assessments ◽  
Fire Extinguishing ◽  
Safety Improvement ◽  
Foreign Countries ◽  
Relevant Task

Fire safety of nuclear power plants is a relevant task, which shall be solved using the latest approaches taking into account NPP design and construction practices, including those in foreign countries. The paper describes results of analysis of NPP fire safety in Ukraine based on national and international assessments, identifies problems in this area and presents priority measures aimed at NPP safety improvement, in particular modernization of fire protection of safety system rooms and implementation of gas and powder fire extinguishers at Ukrainian NPPs.

AFCEN RCC-F: A New Standard for the Fire Protection Design of New Built Light Water Nuclear Power Plants

2018 ◽  
Author(s):  
Bernard Gautier ◽  
Mickael Cesbron ◽  
Richard Tulinski
Keyword(s):  
Fire Protection ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Fire Hazard ◽  
Pressurized Water ◽  
Light Water ◽  
Protection Scheme ◽  
Safety Case ◽  
Under Construction

Fire hazard is an important issue for the safety of nuclear power plants: the main internal hazard in terms of frequency, and probably one the most significant with regards to the design costs. AFCEN is publishing in 2018 a new code for fire protection of new built PWR nuclear plants, so-called RCC-F. This code is an evolution of the former ETC-F code which has been applied to different EPR plants under construction (Flamanville 3 (FA3, France), Hinkley Point C (HPC, United Kingdom), Taïshan (TSN, China)). The RCC-F code presents significant enhancement and evolutions resulting from eight years of work by the AFCEN dedicated sub-committee, involving a panel of contributors from the nuclear field. It is now opened to any type of PWR (Pressurized Water Reactor) type of nuclear power plants and not any longer limited to EPR (European Pressurized Reactor) plants. It can potentially be adapted to other light water concepts. Its objective is to help engineers design the fire prevention and protection scheme, systems and equipment with regards to the safety case and the defense in depth taking into account the French and European experience in the field. It deals also with the national regulations, with two appendices dedicated to French and British regulations respectively. The presentation gives an overview of the code specifications and focuses on the significant improvements.

scholarly journals Corrosion Inhibiting Mechanism of Nitrite Ion on the Passivation of Carbon Steel and Ductile Cast Iron for Nuclear Power Plants

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
K. T. Kim ◽  
H. W. Kim ◽  
H. Y. Chang ◽  
B. T. Lim ◽  
H. B. Park ◽  
...  
Keyword(s):  
Cast Iron ◽  
Carbon Steel ◽  
Nuclear Power ◽  
Power Plants ◽  
Ductile Cast Iron ◽  
Inhibition Mechanism ◽  
Nitrogen Compounds ◽  
Nitrite Ion ◽  
Outermost Surface ◽  
Passive Current

While NaNO2addition can greatly inhibit the corrosion of carbon steel and ductile cast iron, in order to improve the similar corrosion resistance,ca.100 times more NaNO2addition is needed for ductile cast iron compared to carbon steel. A corrosion and inhibition mechanism is proposed wherebyNO2-ion is added to oxidize. TheNO2-ion can be reduced to nitrogen compounds and these compounds may be absorbed on the surface of graphite. Therefore, since nitrite ion needs to oxidize the surface of matrix and needs to passivate the galvanic corroded area and since it is absorbed on the surface of graphite, a greater amount of corrosion inhibitor needs to be added to ductile cast iron compared to carbon steel. The passive film of carbon steel and ductile cast iron, formed by NaNO2addition showed N-type semiconductive properties and its resistance, is increased; the passive current density is thus decreased and the corrosion rate is then lowered. In addition, the film is mainly composed of iron oxide due to the oxidation byNO2-ion; however, regardless of the alloys, nitrogen compounds (not nitrite) were detected at the outermost surface but were not incorporated in the inner oxide.

Simulation and Analysis: The Dose Distribution of KBS-3 Spent Nuclear Fuel Canister by MCNP

2010 ◽  
Author(s):  
Bo Yang ◽  
He-xi Wu ◽  
Yi-bao Liu
Keyword(s):  
Cast Iron ◽  
Radioactive Waste ◽  
Nuclear Fuel ◽  
Nuclear Power ◽  
Power Plants ◽  
Spent Nuclear Fuel ◽  
Ductile Cast Iron ◽  
Nuclear Industry ◽  
Spent Fuel ◽  
High Level

With the sustained and rapid development of the nuclear power plants, the spent fuel which is produced by the nuclear power plants will be rapidly rising. Spent fuel is High-level radioactive waste and should be disposed safely, which is important for the environment of land, public safety and health of the nuclear industry, the major issues of sustainable development and it is also necessary part for the nuclear industry activities. It is important to study and resolve the high-level radioactive waste repository problem. Spent nuclear fuel is an important component in the radioactive waste, The KBS-3 canister for geological disposal of spent nuclear fuel in Sweden consists of a ductile cast iron insert and a copper shielding. The ductile cast iron insert provides the mechanical strength whereas the copper protects the canister from corrosion. The canister inserts material were referred to as I24, I25 and I26, Spent nuclear fuel make the repository in high radiant intensity. The radiation analysis of canister insert is important in canister transport, the dose analysis of repository and groundwater radiolysis. Groundwater radiolysis, which produces oxidants (H2O2 and O2), will break the deep repository for spent nuclear fuel. The dose distribution of canister surface with different kinds of canister inserts (I24, I25 and I26) is calculated by MCNP (Ref. 1). Analysing the calculation results, we offer a reference for selecting canister inserts material.

scholarly journals Fire Protection Regulations for Ensuring Fire Safety during Decommissioning Nuclear Power Plants in Korea

2020 ◽  
Vol 34 (3) ◽  
pp. 134-140
Author(s):  
Jung-Wun Kim ◽  
Chan-Geun Park
Keyword(s):  
Fire Protection ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Nuclear Reactor ◽  
The United States ◽  
Regulatory Body ◽  
Basic Technology ◽  
Reactor Types ◽  
First Time

Nuclear power plants (NPPs) in Korea are required to be maintained using a defense in-depth approach to prevent leakage of radioactive substances outside the plant and allow safe shutdown in the event of a fire. Periodic testing must be conducted to ensure that the fire protection facilities perform as required by the laws for various nuclear reactor types. In June 2017, for the first time in Korea, a nuclear plant, Kori Unit 1, was permanently shut down. It was prepared for decommissioning in accordance with the fire protection regulations imposed by the regulatory body. However, a standard protocol is necessary for systematically establishing the fire protection program for decommissioning of NPPs in the future. Therefore, the nuclear legal systems of countries with many operating nuclear power plants, such as the United States, Japan, Canada, and various European countries, were reviewed and guidelines for establishing a fire protection program for decommissioning NPPs was suggested; the fire protection requirements stated by Reg Guide 1.191 (Decommissioning fire protection program for NPPs during decommissioning and permanent shutdown) were used as a model. Suggestions for establishing legal regulations to optimize fire protection programs and secure basic technology for decommissioning NPPs were also made.

Preventive fire protection in nuclear power plants

1988 ◽  
Vol 110 (2) ◽  
pp. 185-189 ◽  
Author(s):  
K. Kordina ◽  
R. Dobbernack
Keyword(s):  
Fire Protection ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants
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