Results 1 - 10 of 1965
Results 1 - 10 of 1965. Search took: 0.024 seconds
|Sort by: date | relevance|
[en] The paper describes the structure of neutron data libraries and upgraded algorithms. The results of test calculations using the new libraries and fuel burnup schemes are also given
[ru]В статье приведено описание структуры нейтронных библиотек и модернизированных алгоритмов. Приводятся результаты тестовых расчетов с использованием новых библиотек и схемы выгорания
[en] Nuclear energy is categorized as the most economic and sustainable energy by IAEA. However, demand and needs for safety and reliability of nuclear industry are increasing after FUKUSHIMA. Especially, reliable data on the stability of nuclear fuel in a reactor and spent fuel is necessary for safety analysis of nuclear reactor and spent fuel. In this study standard reference data were developed and uploaded to the database of national standard reference center. The standard reference data produced in NFDC will be helpful for increasing reliability and stability evaluation of nuclear fuel and spent fuel
[en] The aim of the present work is to examine the possibilities of the MSR-I molten-salt nuclear actinide-incinerator reactor with a cavity-type core as possessing internal and passive safety characteristics and meeting the requirements imposed on next-generation reactors. Starting from the premises that the basic principles of nuclear safety must not differ from all other types of reactors the MSR-I reactor was analyzed in transient processes without activation of the accident protection system in situations where fuel could not be discharged into subcritical drainage tanks because of operator error or failure of the emergency discharge system. A computational study showed that the basic types of emergency situations can be overcome without destroying the protective barriers or actuating accident protection systems.
[en] Highlights: • Fuel rotation in high temperature prismatic core reactors. • Several rotational scenarios were undertaken to optimise the fuel cycle. • The axial fuel rotation impeded the overall lifetime of the core. • The overall best performance saved 40.3% of the cost of fuel rotation. - Abstract: The use of prismatic-core High Temperature Reactors (HTRs), has not yet reached commercialisation, as they are few in operation, and mainly developmental in nature. This work examines numerous models for fuel rotation, thus enhancing and further optimising the fuel lifecycle of a generic HTR. Several rotational scenarios were examined both axially and radially, with radial rotations giving rise to the largest in life extension. Included in the model is a complex analysis of how TRistructural-ISOtropic (TRISO) fuel behaves in operando, increasing the reliably of the model in predicting the benefits of fuel rotation. Finally, an economic assessment was undertaken, which indicted that fuel costs could be reduced by 40.3%, further increasing its economic benefit and efficiency.
[en] This paper is to do a rethinking of nuclear criticality safety management in China, focusing on the safety performance achieved in nuclear fuel cycle in the country over the last 40 years, pointing out the key aspects and the central problems that would result in nuclear criticality accident. A wide range of countermeasures to further strengthen nuclear criticality safety management is suggested. (authors)
[en] The periodic measurements of nuclear fuel geometry state provide the answer about their deformation over the course of their performance in the nuclear reactor. A very big bunch of data can be obtained from the visual inspection - one of the most popular types of the inspection conducted over the nuclear fuel - mainly concerning the surface state of the nuclear fuel. In the case of the geometry deformation measurements, using the visual system relays on the image postprocessing. This approach, however allowing obtaining a big amount of data for further analysis, has relatively low precision and is very subjective. To reach a higher level of precision and to be less vulnerable to a random error more advanced system has to be implemented, possibly a supplementary system. Such an opportunity offers the ultrasonic (UT) system which has been developed over last decades. The UT measuring system, although immature when compared to the visual one, has the steady precision of far less than 1 mm. Currently, the future of the UT measuring system is very promising as it is being under research and development around the world. CVR has joined this pursuit and the first outputs assure the advantages of the system, confirming the system's precision oscillating around 0.1 mm. The UT system is in this way a perfect supplement to the visual system or a substitution in the case of geometry measurements only.
[en] In compliance with provisions of Article 12 of Notice of the Nuclear Safety and Security Commission No.2017-56 (waste.02), transport documents which are prepared by consignors shall be radioactive material transportation statement, and package inspection records. Radioactive material transport statements shall include maximum radioactivity of the radioactive content. The purpose of this study is to independently verify radioactivity in statement on transport of radioactive materials for transported SF in Hanbit site in 2017. For this independent verification, AMORES (Automatic Multi-batch Origen Runner for Evaluation of Spent fuel) code was developed. In this study, the radioactivity by assembly was verified independently using AMORES for transported SF in Hanbit site in 2017. As a result of independent verification, radioactivity results of KHNP and AMORES were similar. The cause and the maximum errors of each mode were as follows: 1) The express mode: cycle difference, up to 2.2% 2) The detail mode: cooling time difference, up to 9.2% The maximum error values were 2.2% in express mode, and 9.2% in detail mode. The current conservative calculation has no problem in terms of transportation, but it is possible that the cost will be overestimated in design of the disposal facility. Reflecting these results, we plan to modify the AMORES to reflect the actual irradiation cycle even in the express mode.
[en] To support more rigorous analysis on global security issues at Sandia National Laboratories (SNL), there is a need to develop realistic data sets without using 'real' data or identifying 'real' vulnerabilities, hazards or geopolitically embarrassing shortcomings. In response, an interdisciplinary team led by subject matter experts in SNL's Center for Global Security and Cooperation (CGSC) developed a hypothetical case description. This hypothetical case description assigns various attributes related to international SNF transportation that are representative, illustrative and indicative of 'real' characteristics of 'real' countries. There is no intent to identify any particular country and any similarity with specific real-world events is purely coincidental. To support the goal of this report to provide a case description (and set of scenarios of concern) for international SNF transportation inclusive of as much 'real-world' complexity as possible -- without crossing over into politically sensitive or classified information -- this SAND report provides a subject matter expert-validated (and detailed) description of both technical and political influences on the international transportation of spent nuclear fuel.