Personnel Radiation Protection at the ITER Nuclear Fusion Facility (original) (raw)
Related papers
Preliminary occupational radiation exposure evaluation related to NET II/ITER
15th IEEE/NPSS Symposium. Fusion Engineering
This paper presents the criteria adopted to evaluate Occupational Radiation Exposure (ORE) during normal operation and maintenance of NET/ITER and some results concerning the fuel cycle systems located in the tokamak and tritium buildings. Prompt radiation, activity concentration, and intake situations as well as number of workers, number of events, and exposure time are considered. Many systems and components, whose location in the plant can affect radiological protection during maintenance and/or surveillance, are identified together with the operations needed for each activity. Accidental conditions and equipment failures have been considered in the special maintenance activity when they are due to events with a high probability of occurrence so that such events might be expected during the life of the plant. Some results are reported showing the ORE figures with reference to the main activities. The total man-Sv/y for the systems and activities considered is about 0.5. Such a result, even if very preliminary and incomplete, means that ORE for the tritium systems of a machine like NET/ITER is not negligible and has to be continuously controlled during the design phase.
Preliminary Occupational Radiation Exposure evaluation related to NET/ITER tritium systems
Journal of Fusion Energy, 1993
This paper presents the criteria adopted to evaluate Occupational Radiation Exposure (ORE) during normal operation and maintenance of NET/ITER and some results concerning the fuel cycle systems located in the tokamak and tritium buildings. Prompt radiation, activity concentration, and intake situations as well as number of workers, number of events, and exposure time are considered. Many systems and components, whose location in the plant can affect radiological protection during maintenance and/or surveillance, are identified together with the operations needed for each activity. Accidental conditions and equipment failures have been considered in the special maintenance activity when they are due to events with a high probability of occurrence so that such events might be expected during the life of the plant. Some results are reported showing the ORE figures with reference to the main activities. The total man-Sv/y for the systems and activities considered is about 0.5. Such a result, even if very preliminary and incomplete, means that ORE for the tritium systems of a machine like NET/ITER is not negligible and has to be continuously controlled during the design phase.
Basic Radiation Protection for the Safe Use of Radiation and Nuclear Technologies
IntechOpen eBooks, 2022
Any use of both ionizing radiation and nuclear technologies requires ensuring appropriate safety and security of persons as well as the adequate protection of the environment. This is why the applications and handling of sources of ionizing radiation should be in line with the relevant national and international standards containing appropriate safety and security requirements and recommendations. In order to understand and follow these standards, it is necessary to assess the related radiation risks, which should be quantified by using specific dosimetry and radiation protection quantities and units. The chapter introduces and discusses these quantities and units aimed at the evaluation of the biological harms attributed to both stochastic and deterministic effects. The correct use and interpretation of radiation quantities are important to follow relevant regulations and to communicate radiation risks to workers and the public. The chapter takes into account the latest situation in the field, relying on the recent position of relevant international expert bodies.
Radiological Safety Analysis for the Main Incidents of the ITER Systems
21st IEEE/NPS Symposium on Fusion Engineering SOFE 05, 2005
Two incidents among those defined for the ITER systems are analysed from the radiological safety point of view due to their major impact on the worker safety: • "In-vessel FW pipe break" • "Heat exchanger leakage". For both incidents no direct personnel exposure is envisaged during the events. Nevertheless, the maintenance activities needed to restore the systems to their original performance are responsible of an increase of the individual dose and of the Occupational Radiation Exposure (ORE). Maintenance scenarios are described for both the after-incidents situations and the related timing and person power are estimated and discussed. Dose rates related to the FW module operations are derived from previous analyses. Original new assessment of the dose rate in the operator position are performed in the current study to evaluate the impact of heat exchanger (HX) tube plugging. The radiological source term for the scenario is the activated corrosion product (ACP) already assessed for previous analysis. The evaluation of the inner surface concentration of ACP is based on the model prepared for the code PACTITER used to assess the source term. Computer models for dose rate assessment are presented. Collective doses for the repair activities following the two incidents are quantified for the maintenance activities to recover both the "in-vessel FW pipe break" and the "heat exchanger leakage".
2015
The Neutral Beam Test Facility (NBTF), also called PRIMA (acronym for Padova Research on ITER Megavolt Accelerator) consists of two separate development test beds currently under construction in Padua (Italy): the ion source test facility, named SPIDER (Source for Production of Ion of Deuterium Extracted from Rf plasma) and the megavolt test facility, called MITICA (acronym for Megavolt ITER Injector & Concept Advancement). Both injectors accelerate negative deuterium and hydrogen ions with a maximum energy of 1 MeV for MITICA and 100 keV for SPIDER, and a maximum beam current of 40 A for both the experiments. Accelerated ions are stopped on a.CuCrZr alloy calorimeter where an intense neutron field is generated following to D-D and D-T reactions. In the present paper, a systematic review of the radiation safety analysis for both injectors is presented. The shielding design is described, including special shielding solutions planned with the aim of allowing personnel access for inspe...
Effective Individual dosimetric control is the main goal of the Program for radiation protection of IRT personnel of the Nuclear Scientific Experimental and Educational Centre (NSEEC). Strict rulesfor work with sources of ionizingradiation on the nuclear facility territoryare imposed in full compliance with the currentEuropean and nationallegislation. We report on the experienceaccumulated in the field of radiationprotection of personnel and environmental monitoring. The staff safety is provided for by using two types of individual dosimeters (TLD and electronic) and two RTL whole-body contamination monitors. The controlof the workplace environmentand monitoring of the radiologicalstatusis achievedby a stationary radiation monitoring system providing continuous monitoring of reactor workplace and its surroundings by continuousmeasuringof gammabackgroundand aerosols and by analyses ofenvironmental samples(aerosols, soils,plants, underground water and rainfall) collected in the protec...
Radiological safety during maintenance of the primary heat transfer system of the ITER plant
Proceedings of 16th International Symposium on Fusion Engineering, 1995
The primary heat transfer system (PHTS) of the ITER plant is devoted to the heat removal from different plasma facing components: the first wall, the blanket, the divertor and the vacuum vessel . The system requires a scheduled or regular maintenance that involve component checlung and changing, and a special maintenance that has a non periodic nature. During the maintenance operations some shelding barrier has to be partly or completely removed and workers are likely to be exposed to an unusual radiological dose.
Radiation Protection Group: Annual Report 2003
The RP Annual Report summarises the activities carried out by CERN’s Radiation Protection Group in the year 2003. It includes contribution from the EN section of the TIS/IE Group on environmental monitoring. Chapter 1 reports on the measurements and estimations of the impact on the environment and public exposure due to the Organisation’s activities. Chapter 2 provides the results of the monitoring of CERN’s staff, users and contractors to occupational exposure. Chapter 3 deals with operational radiation protection around the accelerators and in the experimental areas. Chapter 4 reports on RP design studies for the LHC and CNGS projects. Chapter 5 addresses the various services provided by the RP Group to other Groups and Divisions at CERN, which include managing radioactive waste, high-level dosimetry, lending radioactive test sources and shipping radioactive materials. Chapter 6 describes activities other than the routine and service tasks, i.e. development work in the field of in...
Impact of plant incidents on worker radiation exposure for the SEAFP design
Fusion Engineering and Design, 2001
Fusion power reactors represent a significant source of energy supply with the potential for little adverse safety and environmental impact. Occupational radiation exposure, however, has been recognized as a potential area of concern, due to the significant quantities of activated products generated in a D-T fusion reactor and the need for frequent replacement of reactor components. This study was undertaken to provide a preliminary estimate of the potential impact of plant incidents on the annual station dose of two fusion reactor designs-SEAFP Model 1 (helium-cooled) and Model 2 (water-cooled). The assessment comprised an evaluation of the impact that plant incidents have on the annual station dose of fission reactor plants, and an assessment of the potential dose contribution of some incidents in a fusion reactor plant. The evaluation of water-cooled reactor data indicates that worker overexposures (\ 20 mSv) from plant incidents are rare and that significant overexposures (\ 50 mSv) are even less frequent-of the order of one in 600 reactor-years of operation. Furthermore, the number of workers exposed due to unplanned events is of the order of 0.2% of monitored workers. The evaluation of helium-cooled reactor data indicates better performanceno exposures above 20 mSv have been recorded. The assessment results for SEAFP Models 1 and 2 are consistent with the fission reactor results, however, only one category of incidents has been considered to date.