Image Calibration Based on Dynamic No-Load Data for the 60Co Gantry-Movable Dual-Projection Radiography Inspection System

2020 ◽  
Author(s):  
Li Guangchao ◽  
Cong Peng ◽  
Guo Xiaojing ◽  
Chen Liu ◽  
Ni Minzi ◽  
...  
Keyword(s):  
Inspection System ◽  
Nuclear Materials ◽  
Nuclear Facilities ◽  
Dynamic Correction ◽  
Projection Radiography ◽  
Gas Ionization ◽  
Dual Projection ◽  
Radioactive Sources ◽  
And Control ◽  
Image Calibration

Abstract The 60Co gantry-movable dual-projection radiography inspection system is newly developed, aiming to the inspection of vehicles entering and exiting the nuclear facilities. It adopts two Co-60 radioactive sources and two arrays of gas ionization chambers corresponding to the two sources, respectively. They can move synchronously with the gantry driven by the mechanical and control subsystem. So, dual projections could be obtained through one scan from two different directions. Compared to a single projection, the dual projections make it easier to found hidden objects and distinguish whether a dark area is due to overlapping objects or because there are well-shielded prohibited items such as nuclear materials. Therefore, it is helpful to found well-shielded nuclear materials and prevent them from being stolen. However, problems also come due to the using of two radioactive sources and the moving gantry. For the former one, it will bring about scattering effect between two sources, while for the latter one, the signals of the detectors would fluctuate as the gantry moves, owing to the vibration of collimator and gantry as well as the non-synchronous movement of sources and detectors. So, the radiography projections are needed to be corrected. In response to the second question, the no-load data is repeatedly measured when the gantry is in different positions, then a method of image calibration based on the dynamic no-load data is proposed for this inspection system to replace the correction with average no-load data. Result shows that the corrected no-load image turns smoother, meaning that the method of dynamic correction could effectively improve the radiation image.

The Local Governments’ Management of the Sensitive Information

2010 ◽  
Author(s):  
Shin-etsu Sugawara ◽  
Tomoaki Inamura ◽  
Haruki Madarame
Keyword(s):  
Emergency Preparedness ◽  
Local Governments ◽  
Terrorist Attacks ◽  
Actual Condition ◽  
Inspection System ◽  
Nuclear Materials ◽  
Sensitive Information ◽  
Nuclear Facilities ◽  
Physical Protection ◽  
Nuclear Disaster

After the September 11th terrorist attacks, the Convention on the Physical Protection of Nuclear Material was revised, and many countries have enhanced their regulatory regimes about the management of sensitive information, especially in the physical protection system. Japan also amended the Nuclear Reactor Regulation Law in 2005 in step with this global movement. The major areas of this revision which are associated with sensitive information are as follows: formulation of the Design Basis Threat (DBT), introduction of inspection system of physical protection and obligation of confidentiality of the secret of physical protection. Through this amendment, the responsibilities of the national government and the utilities have been clarified. However, there is no prescription which ordains the role and responsibility of the local governments. In fact, the local governments receive various information from the utilities through the “Safety Agreements” which are concluded between the local governments and the utilities, and the Public Safety Commissions of prefectures are involved in the transportation of nuclear materials. Moreover, the Act on Special Measures concerning Nuclear Emergency Preparedness provides the engagement and the responsibility of the local governments in case of nuclear disaster. In addition, the Civil Protection Law also provides the formulation of local governments’ plans for a response to national emergencies including nuclear disaster which is caused by terrorist attacks. As described above, the local governments are in a position where they can or have to touch the sensitive information in a variety of ways. Originally, the local government employees have obligation of confidentiality by the Local Public Service Act. Thus, about the sensitive information, they have duty to keep secret. However, we are hard to say that there are complete systems to check this obligation, so we can point out that its effectiveness is doubtful. Especially, the sensitive information which is related to nuclear materials is vital for security of the nation as a whole. Under such awareness, we’re studying the change of the local governments’ way of the management of sensitive information accompanied by the strengthening of Japanese nuclear regulation, and the actual condition of it. Now, we interview some local governments’ departments in charge where nuclear facilities are located. In this paper, we discuss the actual condition and the problems around the local governments’ management of the sensitive information.

scholarly journals Knowledge Management in the Decommissioning of Nuclear Facilities in Brazil

2021 ◽  
Vol 8 (3A) ◽  
Author(s):  
Ricardo Bastos Smith ◽  
Tereza Cristina Salvetti ◽  
Ana Paula Gimenes Tessaro ◽  
Júlio Takehiro Marumo ◽  
Roberto Vicente
Keyword(s):  
Knowledge Management ◽  
Nuclear Material ◽  
Radioactive Material ◽  
Nuclear Materials ◽  
Nuclear Facilities ◽  
The People ◽  
Management Techniques ◽  
The One ◽  
And Control ◽  
Periodic Inspections

In the second half of the twentieth century in Brazil, several nuclear facilities were built for the most varied objectives. The largest number of such facilities is at the Nuclear and Energy Research Institute in São Paulo (IPEN-CNEN/SP). For different reasons, some of these facilities had their projects finalized and were deactivated. Some of the equipment was then dismantled, but the respective nuclear and radioactive material remained isolated in the original sites awaiting the proper decommissioning procedures. The Celeste Project is an example of a facility where the nuclear material has been kept, and is subject to Argentine-Brazilian Agency for Accounting and Control of Nuclear Materials (ABACC) periodic inspections. Because of a number of interests, including financial and/or budgeting situations at the institutions, decades have passed without any further action, and the people who withold information and knowledge about these facilities have already moved away from the area or are in the process of. Therefore, because of the absence of knowledge management techniques in force at the time of establishing and operating these installations, this work proposes an analysis about the possible consequences in case of loss of perhaps the only one remaining knowledge, the one from the people who designed those departments and worked there.

Study on Scattering Correction of the 60Co Gantry-Movable Dual-Projection Digital Radiography Inspection System

2020 ◽  
Author(s):  
Minzi Ni ◽  
Guangchao Li ◽  
Zhentao Wang
Keyword(s):  
Digital Radiography ◽  
Development Project ◽  
Linear Mapping ◽  
Detector Array ◽  
Inspection System ◽  
Interference Signal ◽  
Nuclear Facilities ◽  
Radiation Sources ◽  
Dual Projection ◽  
Scattering Noise

Abstract Nuclear safety and security is getting more and more attention all over the world. Vehicles in and out of nuclear facilities need to be strictly inspected to prevent carrying of nuclear materials, explosives or other dangerous items. A new-type vehicle inspection system — 60Co gantry-movable dual-projection digital radiography inspection system is developed in Tsinghua University under the support of China’s Nuclear Energy Development Project, which uses two 60Co as radiation sources. The radiation sources are arranged at the bottom and side of the vehicles to be detected and the ionization chamber detectors are set in the two side of the gantry correspondingly. With moving of the sources and gantry synchronously, the system can obtain both side-view and upward-view images of the vehicles simultaneously [1]. However, there is a problem that the scattered rays from source of one projection can enter the detector array of another projection to form an interference signal. Experiments show that this kind of scattering noise can account for 20%, resulting in blurring and even artifacts, especially in thicker areas of the image. This problem needs to be solved urgently. According to the characteristics of the Compton scattering effect, it is inferred that there is a certain non-linear mapping relationship between the scattering distribution of the detector array of one projection and the mass distribution in the plane of the other projection. This paper attempts to use BP neural network to learn this mapping relationship to quantitatively remove this kind of scattering noise. The results show that this method has certain effects on the removal of artifacts and blur caused by scattering. This method has the advantage of being fast and more targeted, compared with traditional image post-processing methods.

An Overview of the Draft of ‘Nuclear Materials and Radioactive Waste Management Act’

2013 ◽  
Author(s):  
Huan Lin ◽  
Tai-Wei Lan ◽  
Min-Tsang Chang ◽  
Wuu-Kune Cheng
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
Public Involvement ◽  
Nuclear Materials ◽  
Regulatory Body ◽  
Nuclear Facilities ◽  
Radioactive Waste Management ◽  
Regulatory Capacity ◽  
Concept Of Information ◽  
The Impact

The “Nuclear Materials and Radioactive Waste Management Act” (NMRWMA) in Taiwan has been in use since 2002. To promote further administrative efficiency and improve regulatory capacity, an amendment of the act has been initiated by the Atomic Energy Council (AEC). It is now being reviewed by outside experts and related communities so as to include the best understanding of risk management factors. For the future decommissioning challenges of nuclear facilities, the act is also being amended to comply with the regulatory requirements of the decommissioning mandates. Currently the Taiwan government is conducting government reorganization, and AEC will be reformed but will remain as an independent regulatory body. AEC will then be capable of improving the regulatory capacity for facilitating licensing and inspection, ensuring operational safety, environmental protection and public involvement, and giving a more flexible administrative discretion, such as expending the margin of penalty. The amendment is also required to provide a formal legal basis for the Nuclear Backend Fund, and to mandate the waste producers to take responsibility for any final debt repayment. In addition, this amendment promotes measures to prevent accidents or emergencies concerning radioactive materials and facilities and procedures to reduce the impact and effect of any unexpected events. Furthermore, this amendment intends to implement the concept of information transparency and public participation so as to meet the public needs. Finally, radioactive waste final disposal tasks have to be completed by waste producers under the supervision of the AEC.

scholarly journals Characteristics of X-ray and gamma radiation detectors based on polycrystalline CdTe and CdZnTe films

2021 ◽  
pp. 81-86
Author(s):  
Sharifa Utamuradova ◽  
Sultanposha Muzafarova ◽  
Abdulla Abdugafurov ◽  
Kakhramon Fayzullaev ◽  
Elmira Naurzalieva ◽  
...  
Keyword(s):  
Room Temperature ◽  
Specific Resistance ◽  
Radiation Detectors ◽  
Columnar Structure ◽  
Nuclear Materials ◽  
X Ray ◽  
Molybdenum Substrate ◽  
Cdznte Detectors ◽  
And Control ◽  
Polycrystalline Semiconductor

Based on CdTe and CdZnTe detectors a number of promising devices were created, which found their application in metallurgy, in solving the problems of customs control and control of nuclear materials, as well as matrix detectors created for the manufacture of medical devices and devices for space research. Detectors, created on the basis of polycrystalline semiconductor CdTe and CdZnTe films with a columnar structure on a molybdenum substrate with a thickness d = 30150 μm, had a specific resistance p > 10^5 10^8 W-cm. The energy resolution of the CdTe and CdZnTe detectors at room temperature reached ~ 5 keV on the 59.6 keV 241Am line.

Cyber Security Assurance in the Design, Implementation, and Operation of NPP I&C Systems

2020 ◽  
pp. 323-348
Author(s):  
Oleksandr Klevtsov ◽  
Artem Symonov ◽  
Serhii Trubchaninov
Keyword(s):  
Control Systems ◽  
Cyber Security ◽  
Regulatory Framework ◽  
Nuclear Facilities ◽  
Stages Of Development ◽  
Basic Principles ◽  
Security Assurance ◽  
Security Levels ◽  
And Control

The chapter is devoted to the consideration of the issues concerning the cyber security assurance of NPP instrumentation and control systems. A brief overview of the international regulatory framework in the field of cyber security for nuclear facilities is given. The different approaches to the categorization of NPP instrumentation and control systems by cyber security are expressed. The basic principles of cyber security assurance of NPP instrumentation and control systems are considered. The specific measures of cyber security assurance (i.e., graded according to the cyber security levels) on the stages of development, implementation, and operation of NPP instrumentation and control systems are presented.

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