Remote-Controlled Inspection Robot for Nuclear Facilities in Underwater Environment

2009 ◽  
Author(s):  
Harunobu Okihana ◽  
Keiji Iwata ◽  
Yasuhiro Miwa
Keyword(s):  
Radiation Exposure ◽  
Nuclear Power ◽  
Power Plants ◽  
Ccd Camera ◽  
High Dose ◽  
Nuclear Facilities ◽  
Original Design ◽  
Inspection Robot ◽  
Manual Inspection ◽  
Underwater Environment

A remote-controlled inspection robot for nuclear facilities in underwater environment was developed. The Array system of Eddy Current Testing (Array-ECT) is installed on the existing robot that consists of the driving unit and the inspection unit with enlarged Charge-Coupled Device (CCD) camera. It can swim in the tank, crawl on the inner surface of the tank, stay on the inspection area and by its two devices, Array-ECT and enlarged CCD camera, start inspection. Array-ECT can record the color contour image, and also can display oscillograph. This technology had been developed in order to reduce worker’s radiation exposure and improve inspection-ability in nuclear power plants for some Radioactive Waste (RW) tanks. With conventional manual inspection, RW tanks must be examined with the sequence of (a) full drainage and decontamination, (b) scaffolding set-up with workers under high dose, and (c) manual inspection. As such, the inspection is time consuming and workers should have high radiation exposure. With the original robot that has only enlarged CCD camera, inspection can be performed without tank drainage and with minimum worker’s radiation exposure. However, it needs experienced inspector for interpretation of visual examination using enlarged CCD camera. Newly developed robot with Array-ECT and enlarged CCD camera can achieve the same performance using the original robot and an experienced inspector for visual inspection using enlarged CCD camera. The new feature added to the original design (i.e. Array-ECT) eliminates the need for an experienced inspector.

Innovative Robot Technologies for Nuclear Power Plants Inspection and Maintenance

2014 ◽  
Author(s):  
Seungho Kim ◽  
Kyung Min Jung ◽  
Sung Uk Lee ◽  
Hocheol Shin ◽  
Chang Hoi Kim ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
High Dose ◽  
Nuclear Facilities ◽  
Human Errors ◽  
Safety Issues ◽  
Safety And Reliability ◽  
Inspection And Maintenance ◽  
Remote Inspection

Nuclear energy has become the main energy source in Korea, but the safety issues are being debated since the Fukusima accident. In order to guarantee the safety and reliability of nuclear power plants, the uncertainty of human errors are being minimized by utilizing innovative technologies for inspection and maintenance. KAERI has developed robotic systems to upgrade and ensure the safety of nuclear facilities, to detect unusual conditions of facilities through remote inspection and to prevent human workers from high dose radiation with efficient plant maintenance.

Remote-Controlled Inspection Robot for Nuclear Facilities in Underwater Environment

2002 ◽  
Author(s):  
Yasuhiro Miwa ◽  
Syuichi Satoh ◽  
Naoya Hirose
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Grinding Wheel ◽  
Nuclear Facilities ◽  
Inspection Robot ◽  
Inspection Process ◽  
Removal Technologies ◽  
And Performance ◽  
Set Up ◽  
High Level

A remote-controlled inspection robot for nuclear facilities was developed. This is a underwater robot technology combined with inspection and flaw removal technologies. This report will describe the structure and performance of this robot. The inspection robot consists of two parts. The one is driving equipment, and the other is inspection and grinding units. It can swim in the tank, move around the tank wall, and stay on the inspection area. After that it starts inspection and flaw removal with a special grinding wheel. This technology had been developed to inspect some Radioactive Waste (RW) tanks in operating nuclear power plants. There are many RW tanks in these plants, which human workers can be hard to access because of a high level dose. This technology is too useful for inspection works of human-inaccessible areas. And also, in conventional inspection process, some worker go into the tank and set up scaffolding after full drainage and decontamination. It spends too much time for these preparations. If tank inspection and flaw removal can be performed in underwater, the outage period will be reduced. Remote-controlled process can be performed in underwater. This is the great advantage for plant owners. Since 1999 we have been applying this inspection robot to operating nuclear 11 facilities in Japan.

Cyber Security Assessment of NPP I&C Systems

2020 ◽  
pp. 221-238
Author(s):  
Oleksandr Klevtsov ◽  
Artem Symonov ◽  
Serhii Trubchaninov
Keyword(s):  
Control Systems ◽  
Cyber Security ◽  
Nuclear Power ◽  
Power Plants ◽  
Cyber Attacks ◽  
Security Assessment ◽  
Nuclear Facilities ◽  
Security Risks ◽  
Cyber Threats ◽  
And Control

The chapter is devoted to the issues of cyber security assessment of instrumentation and control systems (I&C systems) of nuclear power plants (NPP). The authors examined the main types of potential cyber threats at the stages of development and operation of NPP I&C systems. Examples of real incidents at various nuclear facilities caused by intentional cyber-attacks or unintentional computer errors during the maintenance of the software of NPP I&C systems are given. The approaches to vulnerabilities assessment of NPP I&C systems are described. The scope and content of the assessment and periodic reassessment of cyber security of NPP I&C systems are considered. An approach of assessment to cyber security risks is described.

INTERCOMPARISON ON INTERNAL DOSE ASSESSMENT FOR NUCLEAR POWER PLANTS IN KOREA

2019 ◽  
Vol 186 (4) ◽  
pp. 524-529
Author(s):  
Si Young Kim
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Evaluation Method ◽  
Dose Assessment ◽  
Assessment Procedure ◽  
Internal Dose ◽  
Nuclear Facilities ◽  
International Intercomparison ◽  
Selection Of

Abstract The intercomparison test is a quality assurance activity performed for internal dose assessment. In Korea, the intercomparison test on internal dose assessment was carried out for nuclear facilities in May 2018. The test involved four nuclear facilities in Korea, and seven exposure scenarios were applied. These scenarios cover the intake of 131I, a uranium mixture, 60Co and tritium under various conditions. This paper only reviews the participant results of three scenarios pertinent to the operation of nuclear power plants and adopts the statistical evaluation method, used in international intercomparison tests, to determine the significance values of the results. Although no outliers were established in the test, improvements in the internal dose assessment procedure were derived. These included the selection of intake time, selection of lung absorption type according to the chemical form and consideration of the contribution of previous intake.

scholarly journals Occupational ALARA Planning for Reactor Pressure Vessel Dismantling at Kori Unit 1

2020 ◽  
Vol 17 (15) ◽  
pp. 5346
Author(s):  
Juyoul Kim ◽  
Batbuyan Tseren
Keyword(s):  
Radiation Exposure ◽  
Pressure Vessel ◽  
Nuclear Power ◽  
Power Plants ◽  
Occupational Safety ◽  
Health Management ◽  
Primary Component ◽  
Reactor Pressure Vessel ◽  
Safety And Health ◽  
Reactor Pressure

Assessing workers’ safety and health during the decommissioning of nuclear power plants (NPPs) is an important procedure in terms of occupational radiation exposure (ORE). Optimizing the radiation exposure through the “As Low As Reasonably Achievable (ALARA)” principle is a very important procedure in the phase of nuclear decommissioning. Using the VISIPLAN 3D ALARA planning tool, this study aimed at assessing the radiological doses to workers during the dismantling of the reactor pressure vessel (RPV) at Kori NPP unit 1. Fragmentation and segmentation cutting processes were applied to cut the primary component. Using a simulation function in VISIPLAN, the external exposure doses were calculated for each work operation. Fragmentation involved 18 operations, whereas segmentation comprised 32 operations for each fragment. Six operations were additionally performed for both hot and cold legs of the RPV. The operations were conducted based on the radioactive waste drum’s dimensions. The results in this study indicated that the collective doses decreased as the components were cut into smaller segments. The fragmentation process showed a relatively higher collective dose compared to the segmentation operation. The active part of the RPV significantly contributed to the exposure dose and thus the shielding of workers and reduced working hours need to be considered. It was found that 60Co contained in the stainless steel of the reactor vessel greatly contributed to the dose as an activation material. The sensitivity analysis, which was conducted for different cutting methods, showed that laser cutting took a much longer time than plasma cutting and contributed higher doses to the workers. This study will be helpful in carrying out the occupational safety and health management of decommissioning workers at Kori NPP unit 1 in the near future.

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.

scholarly journals Importance of Advanced Planning of Manufacturing for Nuclear Industry

2016 ◽  
Vol 7 (2) ◽  
pp. 42-49
Author(s):  
Nick Shykinov ◽  
Robert Rulko ◽  
Dariusz Mroz
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Regulatory Compliance ◽  
Pressure Vessels ◽  
Nuclear Industry ◽  
Project Schedule ◽  
Nuclear Facilities ◽  
Project Completion ◽  
Advanced Planning ◽  
And Performance

Abstract In the context of energy demands by growing economies, climate changes, fossil fuel pricing volatility, and improved safety and performance of nuclear power plants, many countries express interest in expanding or acquiring nuclear power capacity. In the light of the increased interest in expanding nuclear power the supply chain for nuclear power projects has received more attention in recent years. The importance of the advanced planning of procurement and manufacturing of components of nuclear facilities is critical for these projects. Many of these components are often referred to as long-lead items. They may be equipment, products and systems that are identified to have a delivery time long enough to affect directly the overall timing of a project. In order to avoid negatively affecting the project schedule, these items may need to be sourced out or manufactured years before the beginning of the project. For nuclear facilities, long-lead items include physical components such as large pressure vessels, instrumentation and controls. They may also mean programs and management systems important to the safety of the facility. Authorized nuclear operator training, site evaluation programs, and procurement are some of the examples. The nuclear power industry must often meet very demanding construction and commissioning timelines, and proper advanced planning of the long-lead items helps manage risks to project completion time. For nuclear components there are regulatory and licensing considerations that need to be considered. A national nuclear regulator must be involved early to ensure the components will meet the national legal regulatory requirements. This paper will discuss timing considerations to address the regulatory compliance of nuclear long-lead items.

Steam Generator Replacement Project at TVA’s Sequoyah Unit 1 Nuclear Power Plant

2004 ◽  
Author(s):  
Myron R. Anderson
Keyword(s):  
Steam Generator ◽  
Nuclear Power ◽  
Power Plants ◽  
Reactor Power ◽  
Original Design ◽  
Pressurized Water ◽  
Repair Work ◽  
Building Roof ◽  
Tennessee Valley ◽  
Generator Replacement

Pressurized Water Reactor Power Plants have at times required that large components be replaced (steam generators weighing 750,000 lbs) which have necessitated performing first time modifications to the plant that were unintended during the original design. The steam generator replacement project at Tennessee Valley Authority (TVA’s) Sequoyah Nuclear Power Station necessitated (1) two large temporary openings (21’×45’) in the plant’s Shield Building roof (2’ thick concrete) by hydro-blasting to allow the removal of the old generators and installation of the new, (2) removal and repair of the concrete steam generator enclosure roofs (20’ diameter, 3’ thick) which were removed by wire saw cutting and (3) the seismic qualification of; the design and construction of an extensive ring foundation for; the use of one of the world largest cranes to remove these components through the roof. This removal and replacement process had to be performed in an expeditious manner to minimize the amount of time the plant is shutdown so the plant could return to providing power to the grid. This paper will address some of the many technical and construction considerations required to perform this demolition and repair work safely, efficiently and in a short as possible duration.

The Regulatory Framework for Safe Decommissioning of Nuclear Power Plants in Korea

2013 ◽  
Author(s):  
Sangmyeon Ahn ◽  
Jungjoon Lee ◽  
Chanwoo Jeong ◽  
Kyungwoo Choi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Regulatory Framework ◽  
International Standards ◽  
Current Status ◽  
Nuclear Facilities ◽  
Safety Requirement ◽  
Regulatory Review ◽  
Safety Standards

We are having 23 units of nuclear power plants in operation and 5 units of nuclear power plants under construction in Korea as of September 2012. However, we don’t have any experience on shutdown permanently and decommissioning of nuclear power plants. There are only two research reactors being decommissioned since 1997. It is realized that improvement of the regulatory framework for decommissioning of nuclear facilities has been emphasized constantly from the point of view of IAEA’s safety standards. It is also known that IAEA will prepare the safety requirement on decommissioning of facilities; its title is the Safe Decommissioning of Facilities, General Safety Requirement Part 6. According to the result of IAEA’s Integrated Regulatory Review Service (IRRS) mission to Korea in 2011, it was recommended that the regulatory framework should require decommissioning plans for nuclear installations to be constructed and operated and these plans should be updated periodically. In addition, after the Fukushima nuclear disaster in Japan in March of 2011, preparedness for early decommissioning caused by an unexpected severe accident became important issues and concerns. In this respect, it is acknowledged that the regulatory framework for decommissioning of nuclear facilities in Korea need to be improved. First of all, we focus on identifying the current status and relevant issues of regulatory framework for decommissioning of nuclear power plants compared to the IAEA’s safety standards in order to achieve our goal. And then the plan is established for improvement of regulatory framework for decommissioning of nuclear power plants in Korea. It is expected that if the things will go forward as planned, the revised regulatory framework for decommissioning could enhance the safety regime on the decommissioning of nuclear power plants in Korea in light of international standards.

Study on a Methodology of Human Factor Engineering Operating Experience Review for Nuclear Power Plant

2010 ◽  
Author(s):  
Danying Gu ◽  
Shuhui Zhang ◽  
Zhonghe Ning
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Human Factor ◽  
Operating Experience ◽  
Sources Of Information ◽  
Nuclear Facilities ◽  
Human Factor Engineering ◽  
Design Procedures ◽  
Function Allocation ◽  
Review Criterion

The reviewing of operating experience at nuclear power plants (NPP) is not only critically important to safe and reliable operations, but also useful to guide the design of new plants which are similar to the current one under review. How to identify and analyze the safety-related operating experience and then implement a more extensive review is a vital and challengeable issue. In this paper, a methodology of human factor engineering (HFE) operating experience review (OER) is proposed for NPP. The need for the application of HFE in the life cycle activities of NPP and other nuclear facilities has been demonstrated by plant operating histories and regulatory and industry reviews. As a very important element of HFE, the OER is performed from the beginning of the design process. The main purpose of performing an OER is to verify that the applicant has identified and analyzed HFE-related safety problems and issues in previous designs that are similar to the current one. In this way, negative features associated with predecessor designs may be avoided in the current NPP design while retaining positive features. The research of OER concentrates on the aspect of review criterion, scope and implementation procedure of the HFE-related operating experience. As the NRC requirement, the scope of operating experience can be divided into six types in accordance with sources of information. The implementation procedures of USA and China are introduced, respectively. The resolution of HFE OER issues involve function allocation, changes in automation, HSI equipment design, procedures, training, and so forth. The OER conclusions can contribute to other HFE activities and improve the safety, reliability and usability of the HSI design in NPP.

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