scholarly journals Influence of Optic Cable Construction Parts on Recovery Process after Gamma Irradiation

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 599
Author(s):  
Zuzana Šaršounová ◽  
Vít Plaček ◽  
Václav Prajzler ◽  
Kateřina Masopustová ◽  
Petr Havránek
Keyword(s):  
Refractive Index ◽  
Nuclear Power ◽  
Power Plants ◽  
Healing Process ◽  
Glass Structure ◽  
Recovery Process ◽  
Optical Fibres ◽  
Fibre Optic ◽  
Radiation Resistant ◽  
In The Beginning

Fibre optic cables are widely used as communication cables in Instrumentation and Control (I&C) systems. In the case of nuclear power plants (NPPs), using optic cables in mild environments outside of containment areas are very common. However, at present, there is a need for fibre optic cables to be used in containment areas, i.e., with radiation. An optical fibre consists of a highly transparent core that possesses a higher refractive index than the surrounding transparent cladding, which possesses a lower refractive index. Most optical fibres are manufactured from glass (silica with required dopants) which is created at high temperatures from the reaction between gasses. The glass used in optical fibres is sensitive; it becomes dark during exposure to radiation, which compromises the optic functions. That is why there has been a slow infiltration of optic cable in NPP containment areas. Radiation resistant optic fibres have been developed. Although these fibres are called “radiation resistant,” they go through a darkening process (absorbance increase) as well, but not as quickly. Immediately after the irradiation has stopped, a recovery process starts in the glass structure. During this period, optical losses of the glass improve, but not to the original level as before the irradiation. During the testing of optic cables for the installation in nuclear power plant containment areas, we observed an unusual recovery process. In the beginning, a healing effect was observed. However, after a few days of recovery, the healing process stopped, and the trend changed again as a worsening of the optical properties was observed. This paper describes experiments which explain the reasons for such an unexpected behaviour.

scholarly journals Reactor performance, system reliability, instrumentation and control

2020 ◽  
Vol 6 ◽  
pp. 43
Author(s):  
Andreas Schumm ◽  
Madalina Rabung ◽  
Gregory Marque ◽  
Jary Hamalainen
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Lessons Learned ◽  
Software Systems ◽  
Reactor Performance ◽  
Horizon 2020 ◽  
Term Operation ◽  
In The Beginning ◽  
Electrical Cables

We present a cross-cutting review of three on-going Horizon 2020 projects (ADVISE, NOMAD, TEAM CABLES) and one already finished FP7 project (HARMONICS), which address the reliability of safety-relevant components and systems in nuclear power plants, with a scope ranging from the pressure vessel and primary loop to safety-critical software systems and electrical cables. The paper discusses scientific challenges faced in the beginning and achievements made throughout the projects, including the industrial impact and lessons learned. Two particular aspects highlighted concern the way the projects sought contact with end users, and the balance between industrial and academic partners. The paper concludes with an outlook on follow-up issues related to the long term operation of nuclear power plants.

The Development of Radiation-Resistant RF Tags for Use at Nuclear Power Plants

2013 ◽  
Author(s):  
Nobuyuki Teraura ◽  
Kunio Ito ◽  
Naoki Takahashi ◽  
Kouichi Sakurai
Keyword(s):  
Radiation Exposure ◽  
Radiation Damage ◽  
Radio Frequency Identification ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Automatic Data ◽  
Radiation Resistant ◽  
Rf Tags ◽  
Rf Tag

RF tags based on RFID (Radio-frequency Identification) technology have been widely used in various fields including power plant construction and maintenance for the purpose of improving the identification and traceability of the many components in the facility. To date, various types of tags have been developed, including tags that are resistant to chemicals or high-temperature environments, which are used in specialized fields. When considering widespread use of RF tags in nuclear power plants, there is a concern about the effects of radiation on the RF tags, because the data stored in the tag may receive radiation damage, resulting in corruption of data. Here, we describe a newly designed RF tag that achieves resistance to radiation damage by attaching a radiation shield layer and incorporating automatic data-correction software. This radiation-resistant RF tag has been tested under real radiation exposure fields to verify the intended radiation-resistant functions. It is expected that the use of these radiation-resistant RF tags with a data reader and database system will increase the capabilities of RF tags applied to nuclear power plants and it is also expected to lead to reductions in worker radiation exposure doses.

Silica-based optical fibres with refractive index profiles tailored in a region of 1.46–1.62 for fibre-optic chemical detection

2005 ◽  
Vol 107 (1) ◽  
pp. 93-97 ◽  
Author(s):  
Ivan Kasik ◽  
Vlastimil Matejec ◽  
Miroslav Chomat ◽  
Milos Hayer ◽  
Jan Mrazek ◽  
...  
Keyword(s):  
Refractive Index ◽  
Chemical Detection ◽  
Optical Fibres ◽  
Fibre Optic

Supporting societal and economic dynamics of recovery: lessons from Chernobyl and Fukushima

2021 ◽  
pp. 014664532110068
Author(s):  
Thierry Schneider ◽  
Jacques Lochard
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Recovery Process ◽  
Radiological Protection ◽  
Community Life ◽  
Economic Dynamics ◽  
Protective Actions ◽  
Complex Process ◽  
Accident Management ◽  
Fukushima Daiichi

This paper does not necessarily reflect the views of the International Commission on Radiological Protection. Beyond the consideration of radiological aspects, the rehabilitation of living and working conditions after a large nuclear accident is a complex process in which all dimensions of individual and community life are involved and interconnected. Responsibles of socio-economic entities are facing various difficulties/challenges, including the implementation of protective actions for ensuring the protection of employees, the continuity of production of good-quality products in affected areas, and restoring the confidence of consumers. For affected local communities, the deployment of a socio-economic programme is essential to enable a sustainable future while recognising that a return to the pre-accident situation is generally not achievable. In this context, supporting the societal and economic dynamics of the recovery process requires the adoption of specific governance mechanisms respecting a series of ethical and social values, as highlighted by lessons from the post-accident management of the Chernobyl and Fukshima accidents at Chernobyl and Fukushima Daiichi nuclear power plants.

scholarly journals CITIES AND THEIR RESIDENTS AFTER A RADIATION ACCIDENT (KYIV AND FUKUSHIMA CASES)

2017 ◽  
pp. 67-84
Author(s):  
Nataliya Baranovska ◽  
Mihoyashi Yukiko
Keyword(s):  
Urban Space ◽  
Outdoor Recreation ◽  
Nuclear Power ◽  
Power Plants ◽  
Radiation Background ◽  
Sanitary Condition ◽  
The Status ◽  
Japanese City ◽  
In The Beginning ◽  
The City

The article is an attempt to summarize the experience of coping with urban problems caused by major human-made disasters. Based on the analysis of archival materials and other sources, the authors reproduce the situation in particular in Kyiv after the accident at the 4th Unit of the Chornobyl Nuclear Power Plant in 1986. It is proved that the official claim that radioactive emissions from the destroyed reactor bypassed the city was false. Data on the actual situation of radioactive contamination of the territory of Kyiv was published in Kyiv newspapers only in the beginning of 1991. However, both the central and local authorities have made some efforts to overcome the harmful effects of the accident. Among its main activities are work on the study of pollution of the hydrosphere, elaboration of methods of water purification and practical steps to ensure its population in the contaminated territories; organization of active radiation control of food, agricultural products, markets, dairies, meat-packing plants, as well as the territory of the city, motor transport, etc .; improvement and improvement of the sanitary condition of the urban space, resolving the issue of bio-waste disposal, decontamination of wildlife objects, residential, public and technical premises. The city authorities have taken many steps to protect the population of Kyiv from the possible effects of radiation contamination - for example, trying to regulate outdoor recreation. However, the authors claim, when the radiation background in Kyiv began to rise, no special measures for the protection of children were taken, and only in the second half of May, some children were sent away from the city. Already during independent development of Ukraine, work was being done to streamline the status of children affected by the Chernobyl disaster and, accordingly, to provide them with certain privileges defined by the legislation. It is noted that similar processes took place in 2011 and the Japanese city of Fukushima. Authors conclude, that the incompleteness of the process of dealing with the consequences of accidents at nuclear power plants in Ukraine and Japan, the likelihood of recurrence of such events, make the long experience of Kyiv significant for the residents of Fukushima and the human community as a whole.    

Proposal of Inspection Rationalization Method and Application for Sodium Cooled Fast Reactor

2020 ◽  
Author(s):  
Yada Hiroki ◽  
Takaya Shigeru ◽  
Enuma Yasuhiro
Keyword(s):  
Fast Reactor ◽  
Nuclear Power ◽  
Power Plants ◽  
Assessment Method ◽  
Main Concept ◽  
Support Tool ◽  
Technical Requirements ◽  
Asme Code ◽  
Leakage Monitoring ◽  
In The Beginning

Abstract In order to rationalize maintenance for nuclear power plants, it is necessary to develop optimize maintenance plan by considering characteristics of each plant. In sodium-cooled fast reactor, there are constraints on inspections due to the specialty of handling sodium equipment, that is one of the important points when considering rationalization of maintenance. To solve this problem, we proposed a basic concept of maintenance optimization scheme that is a design support tool in order to develop maintenance strategy, based on “system based code (SBC)”. SBC is a concept to optimize the reliability of a nuclear power plant by consideration of all related technical requirements. “ASME Code Case N-875” and “ASME Boiler and Pressure Vessel Code, Section XI, Division 2 (RIM)” based on system based code were already developed as standards for inspection. One of the proposed scheme goals is to make a concrete way of necessary assessment method. Another is to provide several combinations of design and maintenance, and information for owner in order to choose the acceptable combination. In the beginning, we are working to develop the scheme that can be applied to sodium fast reactor as the main concept of next generation reactor. In this context, primary heat transfer system (PHTS) piping of fast reactor was evaluated by the scheme. This piping was chosen because it is major significant component and the inspection have constraint conditions that need preparation work. As a result, design candidate (e.g. single and double wall piping) and inspection candidate (e.g. ultrasonic testing and continues leakage monitoring) combinations along with benefit of each cases were provided.

The Effects of Ion Implantation on the Surface Features of Inconel 600

1985 ◽  
Vol 43 ◽  
pp. 288-289
Author(s):  
John D. Rubio
Keyword(s):  
Grain Boundary ◽  
Ion Implantation ◽  
Nuclear Power ◽  
Power Plants ◽  
Surface Region ◽  
Selective Dissolution ◽  
Boundary Region ◽  
Near Surface ◽  
Inconel 600 ◽  
Steam Generator Tubing

The degradation of steam generator tubing at nuclear power plants has become an important problem for the electric utilities generating nuclear power. The material used for the tubing, Inconel 600, has been found to be succeptible to intergranular attack (IGA). IGA is the selective dissolution of material along its grain boundaries. The author believes that the sensitivity of Inconel 600 to IGA can be minimized by homogenizing the near-surface region using ion implantation. The collisions between the implanted ions and the atoms in the grain boundary region would displace the atoms and thus effectively smear the grain boundary.To determine the validity of this hypothesis, an Inconel 600 sample was implanted with 100kV N2+ ions to a dose of 1x1016 ions/cm2 and electrolytically etched in a 5% Nital solution at 5V for 20 seconds. The etched sample was then examined using a JEOL JSM25S scanning electron microscope.

Work structure in nuclear power plants

1983 ◽  
Author(s):  
Marjorie B. Bauman ◽  
Richard F. Pain ◽  
Harold P. Van Cott ◽  
Margery K. Davidson
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Work Structure
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