Materials Unconditional Release Practices

2001 ◽  
Author(s):  
Lucien Teunckens
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Waste Treatment ◽  
Nuclear Research ◽  
Electricity Production ◽  
Research Centre ◽  
Nuclear Facilities ◽  
Treatment Facilities ◽  
Interim Storage ◽  
Reprocessing Plant

Abstract Belgium started its nuclear programme quite early. The first installations were constructed in the fifties, and presently, more than 55% of the Belgian electricity production is provided by nuclear power plants. After 30 years of nuclear experience, Belgium started the decommissioning of nuclear facilities in the eighties with two main projects: the BR3-PWR plant and the Eurochemic reprocessing plant. The BR3-decommissioning project is carried out at the Belgian Nuclear Research Centre, while the decommissioning of the former Eurochemic reprocessing plant is managed and operated by Belgoprocess n.v., which is also operating the centralised waste treatment facilities and the interim storage for Belgian radioactive waste.

Nuclear Power Plant Decommissioning in Germany: Projects, Regulation and Experience

2009 ◽  
Author(s):  
Leopold Weil ◽  
Bernd Rehs
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Energy ◽  
Radioactive Decay ◽  
Federal State ◽  
Regulatory Body ◽  
Nuclear Facilities ◽  
Interim Storage ◽  
Near Future ◽  
Selection Of

In Germany, altogether 19 nuclear power plants (NPPs) and prototype reactors have been permanently shut down. For 15 NPPs the dismantling is in progress with “green-field conditions” as planning target. Two units were completely dismantled and two are in safe enclosure. The main legal provision for all aspects of the peaceful use of nuclear energy in Germany is the Atomic Energy Act (AtG), which also contains the basic legal conditions for the decommissioning of nuclear facilities. It stipulates that decommissioning is subject to a licence by the regulatory body of the respective Federal State (Land). An emerging decommissioning practice in Germany is the removal of complete undismantled large components and their transport to interim storage facilities. During the period of storage, the radionuclide inventory of the components will decrease due to radioactive decay and the subsequent segmentation of the components can be done with less radiation protection effort. The commissioning of the Konrad repository in the near future might have consequences on planning of decommissioning, regarding the selection of a decommissioning strategy and the waste management.

Decommissioning of Obsolete Nuclear Facilities in the Nuclear Research Institute Rez

2011 ◽  
Author(s):  
Josef Podlaha ◽  
Karel Svoboda ◽  
Eduard Hansli´k
Keyword(s):  
Czech Republic ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Research ◽  
Current Status ◽  
Joint Stock Company ◽  
Nuclear Facilities ◽  
Nuclear Research Institute ◽  
The Czech Republic ◽  
Research Institute

After more than 55 years of activities of the Nuclear Research Institute Rez (NRI) in the nuclear field, there are some obsolete nuclear facilities that shall be decommissioned. NRI is a leading institution in all areas of nuclear R&D in the Czech Republic. NRI has had a dominant position in the nuclear programme since it was established in 1955 as a state-owned research organization and it has developed to its current status. In December 1992, NRI has been transformed into a joint-stock company. The Institute’s activity encompasses nuclear physics, chemistry, nuclear power, experiments at the research reactor and many other topics. Main issues addressed in NRI in the past decades were concentrated on research, development and services provided to the nuclear power plants operating VVER reactors, development of chemical technologies for fuel cycle and irradiation services to research and development in the industrial sector, agriculture, food processing and medicine. The NRI operates two research nuclear reactors, many facilities as a hot cell facility, research laboratories, technology for radioactive waste (RAW) management, radionuclide irradiators, an electron accelerator, etc. The obsolete facilities to be decommissioned comprise various research facilities and facilities for RAW management. Decommissioning of nuclear facilities NRI is the only ongoing decommissioning project in the Czech Republic. Decommissioning started in 2003 and will be finished in 2014. Some facilities have already been successfully decommissioned.

Global Radioxenon Emission Inventory from Nuclear Research Reactors

2021 ◽  
Author(s):  
Martin B. Kalinowski ◽  
Pouneh Tayyebi ◽  
Michael Lechermann ◽  
Halit Tatlisu
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Emission Inventory ◽  
Noble Gas ◽  
Nuclear Research ◽  
Radioactive Isotopes ◽  
Nuclear Facilities ◽  
Research Reactors ◽  
Underground Nuclear Explosions ◽  
Nuclear Explosions

AbstractTo monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), the International Monitoring System (IMS) is being established which will include 40 sensor systems for atmospheric xenon radioactivity. Radioactive isotopes of the noble gas xenon provide the most likely observable radioactive signatures of underground nuclear explosions. These isotopes are frequently detected by IMS noble gas systems as a result of normal operational releases from different types of nuclear facilities including nuclear power plants (NPPs), medical isotope production facilities (MIPFs), and nuclear research reactors (NRRs). Improved knowledge of the contribution of different emission sources on IMS observations strengthens the screening of radioxenon measurements to exclude observations not relevant to emissions from a nuclear explosion. The contribution of NPPs and MIPFs to the global radioxenon emission inventory is fairly well understood. NRRs have yet to be systematically assessed. This paper is the first attempt to assess the total emission inventory of NRRs expressed as annual total discharges. The results can enhance understanding of those sources most likely to impact IMS background observations and to guide future studies on contributions to IMS station background.

Data-based kernel density equations for probability distributions of releases of CTBT-relevant radioxenon isotopes from nuclear facilities and when arriving at IMS stations after atmospheric transport

2021 ◽  
Author(s):  
Martin Kalinowski ◽  
Boxue Liu
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Explosion ◽  
Atmospheric Transport ◽  
Isotopic Ratio ◽  
Probability Distributions ◽  
Kernel Density ◽  
Nuclear Research ◽  
Nuclear Facilities ◽  
Data Set

<p>For the International Monitoring System (IMS) to be effective, it is vital that nuclear explosion signals can be distinguished from natural and man-made radioactivity in the atmosphere. The International Data Centre (IDC) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) applies standard event screening criteria, with the objective of characterizing, highlighting, and thereby screening out, events considered to be consistent with natural phenomena or non-nuclear explosive, man-made phenomena. The objective of this study is to apply the kernel density (KD) approach to generate and investigate probability distributions of isotopic ratios for radioxenon releases from certain types of sources. The goal is to create probability density functions that could be applied e.g. with a Bayesian method to determine the probability whether an IMS observation can be explained by known sources or could possibly be caused by a nuclear explosion. KD equations for nuclear facility releases are derived from the data set of the radioxenon emission inventory of all nuclear power plants and all nuclear research reactors, as well as selected medical isotope production facilities in the calendar year 2014. For all types of sources, KD equations will be linked with isotopic ratio calculations that connect the sources and IMS stations as receiver.</p>

Spanish Approach to Large Decommissioning Projects

2011 ◽  
Author(s):  
Juan Luis Santiago ◽  
Alejandro Rodri´guez
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Nuclear Research ◽  
Lessons Learned ◽  
Research Centre ◽  
Nuclear Facilities ◽  
Material Management ◽  
Site Remediation ◽  
Key Aspects

The Spanish experience related to the decommissioning of nuclear facilities includes the decommissioning of the Vandello´s I Nuclear Power Plant, the decommissioning of the CIEMAT Nuclear Research Centre and the decommissioning of the Jose´ Cabrera Nuclear Power Plant. This paper reviews the key aspects of these projects and describes the lessons learned related to preparatory activities, auxiliary facilities, decommissioning technologies, material management and site remediation and release.

Using Probabilistic Criteria in an Assessment of the Potential Radiological Consequences of the Decommissioning of a Nuclear Research Reactor

2013 ◽  
Author(s):  
Christian Wallner ◽  
Anna-Maria Rall ◽  
Severin Thummerer
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Research Reactor ◽  
Nuclear Research ◽  
Exposure Dose ◽  
Occurrence Frequency ◽  
Normal Operation ◽  
Nuclear Facilities ◽  
Nuclear Research Reactor

In order to assess the risk of radiological consequences of incidents and accidents in nuclear facilities it is important to contemplate their frequency of occurrence. It has to be shown that incidents and accidents occur sufficiently seldom according to their radiological consequences i. e. the occurrence frequency of radiological doses has to be limited. This is even demanded by the German radiation protection ordinance (StrlSchV), which says that in nuclear facilities other than nuclear power plants (NPP) in operation and for decommissioning, the occurrence frequency of incidents and accidents shall be contemplated in order to prove the design of safety measures and safety installations. Based on the ideas of the ICRP64, we developed a risk based assessment concept for nuclear facilities, which fulfils the requirements of the German regulations concerning dose limits in normal operation and design basis accidents. The general use of the concept is dedicated to nuclear facilities other than nuclear power plants (NPP) in operation and for decommissioning, where the regulation of risk assessment is less sophisticated. The concept specifies occurrence frequency limits for radiation exposure dose ranges, i. e. the occurrence frequency of incidents and accidents has to be limited according to their radiological effects. To apply this concept, scenarios of incidents and accidents are grouped in exposition classes according to their resulting potential effective dose to members of the general public. The occurrence frequencies of the incidents and accidents are summarized in each exposition class whereas the sum must not exceed the frequency limits mentioned above. In the following we introduce the application of this concept in the assessment of the potential radiological consequences of the decommissioning of a nuclear research reactor. We carried out this assessment for the licensing process of the decommissioning on behalf of German authorities.

CASTOR® BR3: Design of a Transport and Storage Cask for Spent Fuel From a Belgian Nuclear Power Plant

2001 ◽  
Author(s):  
Ulrich Knopp
Keyword(s):  
Nuclear Power ◽  
Storage Period ◽  
Nuclear Research ◽  
Ductile Cast Iron ◽  
Radioactive Material ◽  
Research Centre ◽  
Spent Fuel ◽  
Interim Storage ◽  
And Storage

Abstract The CASTOR® BR3 cask has been designed and manufactured to accomodate irradiated fuel (U and MOX) from the BR3 test reactor at the nuclear research centre SCK/CEN in Dessel near Mol, Belgium, which is currently being dismantled. The CASTOR® BR3 is designed as a Type B(U)F package for transport and will be licensed in Belgium. In addition, the CASTOR® BR3 needs a license as a storage cask to be operated in an interim cask storage facility. To obtain these licenses, the cask design has to observe the international regulations for the safe transport of radioactive material as well as the special requirements for the cask storage. The CASTOR® BR3 is a member of the CASTOR® family of spent fuel casks, delivered by the German company GNB. In this way, the cask has such typical features as the following: • monolithic cask body made of ductile cast iron; • double-lid system consisting of primary and secondary lid for long-term interim storage of the fuel. This family of casks has been used for over 20 years for transport and storage of spent fuel. In this paper, the IAEA regulatory requirements for transport casks are summarized and it is shown by selected examples how these requirements have been converted into the cask design and the analyses performed for the cask. Finally, the cask features for an interim storage period of up to 50 years will be spotlighted. Main topics are the evaluation of the long term behaviour of selected cask components and the cask monitoring system for the surveillance of the leak tightness of the cask during the storage period.

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.

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