Operational monitoring of the metal of solution pressure vessel reactors at NRC “Kurchatov institute”
Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
Cited by 2 publications
References 3 publications
Evaluating the operational dependability of a pulse research reactor
Aim. For the purpose of substantiating the safety of further operation of the IIN-1 pulsed solution research reactor beyond the design service life, its dependability has been evaluated for the future operation period. The paper aims to describe the criteria and show an example of IIN-1 vessel dependability evaluation.Method. At the stage of IIN-1 design, no dependability criteria were defined, therefore, based on the NP-009-17 general norms of research nuclear reactor safety, an original dependability criterion, the vessel seal, has been chosen. A reactor vessel that, over the period of operation, is subject to cyclic thermomecanical and radiation loads at the moments of nuclear fuel fission pulse, corrosion damage at the moments of solution heating, dynamic forces of chemical microexplosion of the explosive mix during physical experiments, is a hazardous structural element of IIN-1 that is exposed to the highest loads in terms of emergency tolerance and a priority contributor to the overall nuclear and radiation safety of the research installation. The IIN-1 vessel seal and its general dependability define the efficiency of its safety barriers for the environment and personnel over the long operation of the research installation. IIN-1 vessel dependability is evaluated using experimental methods of non-destructive testing aimed at verifying the seal and state of the metal exposed to corroding media, such as metallographical observation of surveillance specimens, mechanical testing, etc. The strength and plastic properties of the vessel’s metal were tested by static tension.Results. The ultimate stress limit, yield strength, impact resistance and percent elongation of the vessel’s material under temporal degradation of its service properties in the course of life ageing have been defined. Based on the results of specimen tests, tables have been drawn up and conclusions have been made regarding the emergency tolerance of the reactor vessel for the future operation period of IIN-1. Metallographic research in terms of the tendency to intercrystalline corrosion were conducted using the AM method according to GOST 6032-58. The key factors have been defined that affect the ageing of the vessel material of a pulsed reactor: fast neutron flux and their integral values in the reactor vessel’s most vulnerable elements and formation of explosive mix (consisting of hydrogen and oxygen) that causes immediate boiling of the fuel and, subsequently, significant cyclic stress in the vessel’s material that can cause permanent deformation. They can eventually disrupt the vessel seal and destroy the reactor. The dependability of the vessel of such nuclear reactor is evaluated through recurrent in-service inspections of the degradation of the metal’s properties, including in terms of corrosion resistance and mechanical strength by examining surveillance specimens. The paper describes the surveillance specimens and the procedure of their examination.Conclusion. The approach suggested in the paper enables predictive assessment of the operational dependability of a solution nuclear reactor in the course of a long operation. The authors suggest key criteria for evaluating the characteristics of a vessel’s safety and dependability state that allow accurately defining the safe life of a research nuclear reactor and verifying the extendibility of its design life.
Evaluating the operational dependability of a pulse research reactor
Aim. For the purpose of substantiating the safety of further operation of the IIN-1 pulsed solution research reactor beyond the design service life, its dependability has been evaluated for the future operation period. The paper aims to describe the criteria and show an example of IIN-1 vessel dependability evaluation.Method. At the stage of IIN-1 design, no dependability criteria were defined, therefore, based on the NP-009-17 general norms of research nuclear reactor safety, an original dependability criterion, the vessel seal, has been chosen. A reactor vessel that, over the period of operation, is subject to cyclic thermomecanical and radiation loads at the moments of nuclear fuel fission pulse, corrosion damage at the moments of solution heating, dynamic forces of chemical microexplosion of the explosive mix during physical experiments, is a hazardous structural element of IIN-1 that is exposed to the highest loads in terms of emergency tolerance and a priority contributor to the overall nuclear and radiation safety of the research installation. The IIN-1 vessel seal and its general dependability define the efficiency of its safety barriers for the environment and personnel over the long operation of the research installation. IIN-1 vessel dependability is evaluated using experimental methods of non-destructive testing aimed at verifying the seal and state of the metal exposed to corroding media, such as metallographical observation of surveillance specimens, mechanical testing, etc. The strength and plastic properties of the vessel’s metal were tested by static tension.Results. The ultimate stress limit, yield strength, impact resistance and percent elongation of the vessel’s material under temporal degradation of its service properties in the course of life ageing have been defined. Based on the results of specimen tests, tables have been drawn up and conclusions have been made regarding the emergency tolerance of the reactor vessel for the future operation period of IIN-1. Metallographic research in terms of the tendency to intercrystalline corrosion were conducted using the AM method according to GOST 6032-58. The key factors have been defined that affect the ageing of the vessel material of a pulsed reactor: fast neutron flux and their integral values in the reactor vessel’s most vulnerable elements and formation of explosive mix (consisting of hydrogen and oxygen) that causes immediate boiling of the fuel and, subsequently, significant cyclic stress in the vessel’s material that can cause permanent deformation. They can eventually disrupt the vessel seal and destroy the reactor. The dependability of the vessel of such nuclear reactor is evaluated through recurrent in-service inspections of the degradation of the metal’s properties, including in terms of corrosion resistance and mechanical strength by examining surveillance specimens. The paper describes the surveillance specimens and the procedure of their examination.Conclusion. The approach suggested in the paper enables predictive assessment of the operational dependability of a solution nuclear reactor in the course of a long operation. The authors suggest key criteria for evaluating the characteristics of a vessel’s safety and dependability state that allow accurately defining the safe life of a research nuclear reactor and verifying the extendibility of its design life.
The method of research nuclear installation conversion at the decommissioning stage
The article examines the problem of forming scientific and technical programs for the conversion of research nuclear installations at the decommissioning stage, which arose in the aspect of justifying the possibility of extending the designated service life of all existing research nuclear reactors in Russia. To solve this problem, a methodology is proposed, which includes an information model and a process description of the necessary step-by-step actions, as well as a set of appendices in the form of documents justifying the most optimal ways to form a project for managing the quality of nuclear reactor conversion processes in relation to special life cycle conditions of specific nuclear reactors. The general view of the methodology is described: principles and methods of construction, structure. An example of the application of this technique in the conversion of the Hydra salt solution pulsed research reactor for the decommissioning stage is given. The purpose of the conversion of the Hydra reactor is to extend the designated service life by replacing non-repairable equipment the vessel. The main criteria for justifying the residual life of the housing are formulated, which are the presence of a safety margin of the housing material, taking into account the accumulated fluence on more vulnerable areas and the justification of the integrity and tightness of the housing. For clarity, the conceptual information model of the methodology for justifying the safety of the process of replacing the Hydra reactor vessel is presented in the form of an Ishikawa diagram. The methodology represents a series of sequential scientific and technical activities, research and a finite number of step-by-step actions to achieve the final goal – extending the service life. The stages of the methodology for justifying the safety of replacing the Hydra reactor vessel are described, such as «clarification of initial data», «performing computational studies and laboratory experiments», «clarification of the requirements of methodological documentation» and «formation of a work plan» and «registration of licensing documents for operation».
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
Contact Info
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Product
Resources
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.
