ITER Radiological & Environmental Monitoring Systems (REMS) L. Perna, F4E REMS-TRO

Transcription

1 ITER Radiological & Environmental Monitoring Systems (REMS) L. Perna, F4E REMS-TRO 1

2 ITER-Procurement Packages F4E contribution to ITER Project For management and costing purposes the ITER project has been subdivided in a number of procurement packages describing at different level of details all systems and sub systems. PPs have been distributed to the seven ITER parties andthey constitute the socalled In kind contribution. F4E is in charge for the detailed design, procurement, manufacturing, transport, testing and commissioning of the Radiological and Environmental Monitoring Systems (REMS). REMS procurement package is a function specification type of PA, meaning that ITER ORGANIZATION (IO) is responsible of the system development up to the conceptual design. Afterward, F4E will be responsible of the preliminary, & final designs, procurement, installation and commissioning of the different systems, sub systems and equipments. L. Perna Barcelona 27/11/2012 2

3 Functional Specification PA L. Perna Barcelona 27/11/2012 3

4 REMS Radiological & Environmental Monitoring Systems REMS provides health and radiological monitoring for workers as well as environmental monitoring for the public, assisting in the protection against ionizing radiation, during the whole life of ITER starting from construction until operations and decommissioning. The radiological monitoring for workers includes radiation and contamination monitoring, sampling, alarm handling, measuring and limiting individual and accumulative doses to workers within the Radiological Controlled Areas at ITER as well as Beryllium monitoring. The radiological monitoring for the environment includes effluents (gaseous and liquid) release monitoring & sampling. The environmental monitoring programme ensures compliance with the French environmental regulation and allows calculation of doses to the public. In addition, the trigger detectors for the HVAC isolation and connection to the Detritiation System and the tritium detectors in Port Cells to initiate a cleaning action by the Detriation System are included. L. Perna Barcelona 27/11/2012 4

5 REM Systems and Sub-systems L. Perna Barcelona 27/11/2012 5

6 Area Radiological Monitoring (SIC 2) Functions of the Area Radiological Monitoring Systems are: To check that radiations levels are within the ITER radiological zoning limits; To check the efficiency of the radiological protection and the confinement; To detect incidents and accidents situations; To provide in real time local warning to personnel on radiological status (normal, abnormal or incidents/accidents) in radiologically controlled areas and especially those related to work places (radiation fields, volumetric radioactive contamination in air exceeding the authorised levels); To provide local warning to personnel about the status of monitors (failures of local devices: monitors or signalling unit) in real time; To provide information about the radiological status of each nuclear building to both the Health Physics Office and to ITER Operator, in the central control room, in order to undertake adequate actions; To provide routine data on the radiological status of the plant to CODAC and CSS. L. Perna Barcelona 27/11/2012 6

7 Area Radiological Monitoring (SIC 2) ARMS functions are accomplished by a combination of fixed, mobile and portable radiation contamination monitors working in conjunction with sampling devices. The selection between fixed and/or mobile and/or portable monitor depend upon: The level of radiation risks expected in each room within the Radiological Controlled Areas; The evolution (impact) of the risk, which may require evacuation of workers, The requirement in accessing a specific room (access control), The level of occupancy of the room by workers. Monitors are interconnected with alarm units and the centralized system (ARMS Plant Control System) according to the following distributed architecture. L. Perna Barcelona 27/11/2012 7

8 Area Radiological Monitoring Distributed Architecture L. Perna Barcelona 27/11/2012 8

9 Area Radiological Monitoring (SIC 2) This architecture has been selected in order to : Minimize radiation and magnetic field impacts on the electronic components (placing detectors in process room and main electronics in the corridor or airlocks); Place equipment outside the waste zone; Have an easy access at all times for repairing /testing/calibration (SIC 2); Minimize the exposure of the Health Physics operators during testing, calibration and/or repairing operations; Minimize the cabling between the Main Control Room and rooms in each building; To provide local warning to personnel in case of dangerous radiation levels. Indeed, thereisnoimpactonthelocalalarmsincaseoffailuresofthearmsplantcontrol System or networks; To have a redundancy in displaying the radiological status of the facility: HP Offices and Main Control Room. Monitors must be fail safe and cope with safety requirements of SIC 2 components. The selection of monitoring points compliant with IEC norms L. Perna Barcelona 27/11/2012 9

10 Area Radiological Monitoring (SIC 2) Typical components of this sub system are: Area T, gamma, neutron, particulates monitors; Samplers and sampling lines; Radiological synthesis boxes; Cubicles Plant Control System; L. Perna Barcelona 27/11/

11 Release Monitoring (SIC 1) Release pathways of liquid and airborne radioactive substances have to be monitored and discharges quantified in order to demonstrate compliancy against authorised limits and to determine environment impacts (complying with French Order 26/XI/1999). Stack monitoring (on line and/or off line) of: Tritium; Beta/gamma emitters (activated dust, ACP and Be dust); C 14; Other activated gases (Ar 41). All the liquid effluents (industrial effluents, sanitary effluents, raining water, effluents from controlled areas, and effluents from cooling tower discharges) are sampled and analyzed by the HP. L. Perna Barcelona 27/11/

12 Release Monitoring (SIC 1) Gaseous effluent monitoring (stack monitoring) The release rates of radioactive substances must be determined to fulfil the requirements of the monitoring and balancing radioactive releases. The following sampling and monitoring will be required at each exhaust point: Sampling system, Tritium monitoring, Particulate monitoring, Gas monitoring, Tritium sampling, Particulate sampling, Carbon 14 sampling, Beryllium sampling Air volumetric flow On line monitoring to avoid risk of exceeding authorized thresholds Regulatory accountability L. Perna Barcelona 27/11/

13 Release Monitoring (SIC 1) L. Perna Barcelona 27/11/

14 Release Monitoring (SIC 1) Gaseous release monitoring Sampling according ISO 2889; Redundancy of one line monitoring to avoid risk of plasma operation stop; No redundancy of sampling devices because the replacing time is short (less than 4 hours) comparing to the sampling period (40 hours).; Status (failures), alarms and measurement values will be sent to the CSS by hardwired lines (logics signals) according to the requirement of SIC 1 classification, in order to have a safe and redundant display and to initiate safety actions in case of exceeding authorised threshold; All the data will be sent via two redundant networks to the ARMS Plant Control system (elaborate integrated discharges/ display, record) at the HP office where all REMS information are centralised; The redundant monitors will be supplied by redundant power supply load class safety II 230 Volts. The data (values) shall be recorded according SIC 1 data All the monitoring will be installed in the level L5 Tritium Plant building in two separate places. L. Perna Barcelona 27/11/

15 Release Monitoring (SIC 1) Tritium monitors (volume of ion chamber higher than room monitoring 8 litres ) Tritium monitor based proportional counter (diversity of measure) Detection limit < 10 4 Bq/m 3 Increase the volume of the ion chamber L. Perna Barcelona 27/11/

16 Release Monitoring (SIC 1) Liquid effluent release :Chemical checking All the liquid effluents (industrial effluents and sanitary effluents) are sampled and monitored by external laboratories (outsourced activities) before sending the effluents to the CEA facility; The chemical components monitored are: Oxygen, Azote, Phosphor, Cyanide, Chrome, Lead, Copper, Nickel, Zinc, Manganese, Tin, Iron, Aluminium, Halogen organic components (AOX), Hydrocarbon, Fluoride, Hydrazine, Sodium, Sulphates, Chlorates, Bore and suspended particulate matters according the DAC files; Before the discharge of the storage basins, a fish test will be performed in order to confirm the non toxicity of the water. In addition, toxicological analysis will be performed for the sanitary effluents. Nature Industrial effluents Type of monitoring Location Device Frequency Tritium Emitters βγ Carbon 14 Tank in Radwaste building before transfer to CEA station Sampling + gamma monitoring in front of the transfer pipe Sanitary effluents Tritium Tank of the ITER treatment station Sampling Cooling Tower liquid discharge Tritium Storage basins Sampling Monthly Raining water Tritium Storm basins Sampling Before each transfer Monthly and according to the activities According to the rain falls L. Perna Barcelona 27/11/

17 Environmental Monitoring (SR) Functions of the EM include sampling and measurement of elements which allow calculation of doses to the public. These functions are accomplished by a combination of fixed, portable and movable radiation/contamination monitors working in conjunction with a sampling and inspection program. In addition, chemical monitoring is also included in this sub system. Measurements are centralized in the HP office. An EMS Plant Control System is included with the objective to provide a complete overview of the environment impact of ITER operations outside the ITER ASN and to comply with applicable environmental regulations (French Order 26/XI/1999). Three areas are concerned by the environmental monitoring: The perimeter of ITER Nuclear Installations, Area between ITER INB and the fence of the ITER site, Outside the ITER fence. Environmental monitoring at INB perimeter: Dosimeters/integrators for measuring background radiations; Gamma dose rate monitors; Tritium continuous sampling in air, with discrimination HT/HTO; High volume samplers for continuous air sampling, radioactive particulate. Beryllium sampling to check air concentration. T and C 14, β/γ emitters, chemical and toxic products in the ground water and precipitation. L. Perna Barcelona 27/11/

18 Environmental Monitoring (SR) Environmental monitoring inside the ITER site: Same elements of the environmental monitoring inside the ITER Nuclear Installation. Different sites for sampling and measuring will be selected by IO. Environmental monitoring outside ITER site includes: Radiological monitoring in atmosphere, Chemical monitoring in atmosphere, Terrestrial monitoring, Hydrographic system monitoring (Durance & Verdon water, fish test) Nature Location Device Frequency Type of monitoring Soils (surface) Manual Twice per year Plants ( grass, lichen, holm oak ) In the three environmental stations (2 CEA + new station) Manual Monthly /twice per year Plants for eating : roots Type of monitoring Devices Frequency vegetables, fruits and leaf according the season: carrots, Local agricultural producer Particulate sampling with filter (as DPRC potatoes, onions, salads, (Vinon and Saint Paul Lez α, β, γ Particulate,Be CEA) Continuous sampling, daily replacement ofthe filters tomatoes, chards,courgettes) Durance) Manual Yearly HT/HTO Tritium sampling with bubblers Continuous sampling, weekly replacement of the bubblers Local farmers (Vinon, Greoux Gaz C14 Carbon 14 sampling with bubblers Continuous sampling, replacement of the bubblers every 2 weeks Meat (chiken, sheep, goats) les Bains) Manual Yearly Weekly with a calendar periodicity, for height of water > 6 mm (surface Milk producer(greoux les Rain water Pluviometer 600 cm 2 ) Goat milk bains) Manual Yearly Measurement in real time (daily determine maximun and minimum Wine producer (Greoux les Gamma radiation Gamma detector ( REG 803) value of gamma radiation) Wine (rosé and red) Bains, Pierrevert) Manual Yearly Direction of the wind, speed of the wind, Meteorology Temperature, humidity, pressure Continuousely monitoring Producer at Vinon, Jouques Olive oil ou Saint Paul Lez Durance Manual Yearly Soils Saint Paul Lez Durance Manual Twice per year β,γ,t,obt L. Perna Barcelona 27/11/

19 Environmental Monitoring (SR) This monitoring is composed by monitors/samplers interconnected with a plant control system EMS in the Health Physics office in the PACB building and CODAC system for main Control room according the following architecture. L. Perna Barcelona 27/11/

20 Individual Monitoring (SR) The individual monitoring is composed by the following sub systems: Personnel dosimetry; Contamination checking; Portable and mobile monitors. Personnel Dosimetry: The personal dosimetry system shall monitor worker and visitor doses assuring that the total ITER exposure limits are not exceeded for all radiation/contamination hazards. Dosimeters shall be certified and used in conjunction with a bioassay system. The personal dosimetry system is composed by External dosimetry and Internal dosimetry (bioassay system). The external dosimetry shall monitor and record the gamma, beta and neutron radiation exposure of the workers and visitors. The personal bioassay system shall monitor and assess people for inhaled, ingested and otherwise absorbed radiological isotopes. L. Perna Barcelona 27/11/

21 Individual Monitoring External Dosimetry External dosimetry is intended to monitor and record the gamma, beta and neutron radiation exposure. In compliance with the French Law, two types of external dosimetry are required: Passive dosimetry; Active dosimetry. The functions of passive dosimeters are to provide integrated external doses to personnel over the required time span within the supervised and controlled areas, to perform cumulative doses and to record individual doses received by the workers. For measuring X/γ and β radiations, RPL (Radio Photo Luminescence), TLD (Thermo Luminescence Dosimeter) or OSL (Optically Stimulated Luminescence) are commercially available. Dosimeters based on RPL are presently foreseen due to their energy sensitivity and lower detection threshold, compliance with the new regulation (IEC 62387). IRSN advise using this dosimeter. The passive dosimeters shall be analyzed in the certified external Laboratory. The active dosimeters (electronics dosimeters) shall provide the real time measurement of the equivalent dose and dose rate received by the workers or visitors within the controlled areas. The active dosimeters shall provide alarms (visual and sound) if the level of radiations is over the thresholds authorized in order to evacuate. The active dosimeters record the doses received by the workers or visitors during the presence within the controlled areas. The doses recorded by the active dosimeters shall automatically transfer when the workers leave the controlled area and recorded at the Dosimetry Plant Control System at the HP office. L. Perna Barcelona 27/11/

22 Personal dosimetry : External dosimetry Active dosimetry : Architecture of the dosimetry system The dosimetry system is composed by: Dosimeters n, γ worn by the workers in the controlled areas Dosimeter readers enabling the exchange of data between the dosimeters and the central unit of the dose management system A central unit with special software for dosimetry application L. Perna Barcelona 27/11/

23 Individual Monitoring Internal Dosimetry Internal dosimetry is intended to monitor and record the internal contamination (inhaled, ingested and absorbed radiological isotopes). The results shall be archived in a software dose management and reports should be sent to the safety authority (IRSN) according to French law. An internal dosimetry program will be established in function of the risk and worker s radiological classification. The following contamination risks are taken into account: ACP dust, T and Be. The internal dosimetry is based on in vivo measurement (whole body counting) and radio toxicological analysis (monitoring of urinary and faecal excreta). In addition nasal samples, breathing air analysis, smear tests on the hands which reflect the exposure conditions of the workers, shall be used to track the suspicion of internal contamination. L. Perna Barcelona 27/11/

24 Individual Monitoring Contamination Checking Contamination monitoring for personnel and small items will be installed at the exit of contaminated area and inside the PACB building at the exit of controlled area. The following contamination risks will be taken into account: Dust of ACP (Activated Corrosion Products), Tritium, Beryllium. The following equipment shall be required: Standard hand and foot monitors (friskers); Whole body contamination monitors at the exit of the controlled area; A tritium in breath monitor at the exit of controlled area; Portal Monitor (to enter and exit the nuclear fence). L. Perna Barcelona 27/11/

25 Individual Monitoring Portable and mobile monitors The portable and mobile monitors are used for: Routine inspections, The backup of rooms radiological monitors, Maintenance activities. The portable items of equipment are usually hand held with batteries or hand operated while connected to the supply but they are not connected to the radiological network. These equipment are operated by Health Physics and they are used for maintenance activities and routine inspections: gamma neutron dose map, hot point search, shielding checking, surface contamination checking, ambient contamination by sampling (particulate, Beryllium, water). The mobile monitors are used as backup for room radiological monitors and in the room which are not equipped by permanent monitors. These devices are equipped with integrated displays, alarm and flash lights and are connected to the radiological network. L. Perna Barcelona 27/11/

26 Individual Monitoring Portable and mobile monitors Portable monitors: Χ, beta gamma dose and dose rate, Neutron dose and dose rate, Alpha, beta gamma surface contamination, Tritium in air concentration, Gas in air concentration. Portable Sampling Devices: Air samplers for Be particulates, Air samplers for radioactive aerosols, Tritium in air sampling, Carbon 14 in air sampling, Aqueous samplers. The following types of mobile devices are also foreseen: Gamma monitors for Χ, beta/gamma dose rate measurements, Gas monitors for radioactive gas concentration in air measurements, α/β γ particulates monitors for radioactive α/β γ particulate concentration in air measurements, Tritium in air monitors for tritium concentration in air measurements. L. Perna Barcelona 27/11/

27 Area Beryllium Monitoring (SIC 2) Functions of the Area BerylliumMonitoring sub system are: To assess the potential volumetric Beryllium concentration in air in accessible areas to workers (authorisation to access); To check that Be concentration levels in air are within the ITER Beryllium zoning limits; To check the efficiency of the confinement; To detect the incident or accident situations; To provide information to the Health Physics office and to the ITER operators at the main control room about the Be concentration in the air of the buildings; To provide routine data on the Be concentration in buildings, archived on the CODAC system. Beryllium monitoring is a part of this package though it is not radiological monitoring. Airborne beryllium monitoring shall be implemented in the areas with potential beryllium contamination. L. Perna Barcelona 27/11/

28 Area Beryllium Monitoring Area Beryllium samplers are identical to those used to collect the radioactive particulates. Sampling and monitoring system for Be particulates shall be installed as near as possible to the source. The Be particulates in air shall be collected on a filter after iso kinetic sampling from a duct and analyzed at the HP laboratories. Personal air samplers (PAS) for Be particulates shall be equipped for workers in the areas with potential beryllium contamination. A PAS shall consist of a PAS head with a filter and a PAS pump, and a fresh PAS head shall be worn outside of personal protective clothing after connecting it with a pump with a plastic tube. L. Perna Barcelona 27/11/

29 Laboratories The objectives of laboratories inside the Personnel Access Control Building (PACB) are to take part in the radiological and Be monitoring of the ITER nuclear facilities and the environment. These laboratories are used for the quantification of radionuclides and Beryllium present in the ambient air, effluents (gaseous or liquid) of ITER nuclear facilities and in the environment. In order to reach these objectives, three laboratories are required: ABelaboratory; A HP laboratory; An Environmental laboratory. L. Perna Barcelona 27/11/

30 Laboratories Be laboratory: The laboratory shall perform Be extraction from filters (chemical leaching) followed by measurement by Atomic Absorption Spectrometry. This laboratory shall process up to about 40,000 Be and 60,000 active samples per year in the nuclear phase (5,000 samples/year assembly phase II nuclear phase). This laboratory is also required for the assembly phase II during the installation of components containing Beryllium. Environmental Laboratory: This lab shall support the environmental program measuring the impacts on the environment, according to the ITER engagement (DAC files). Currently, this laboratory shall prepare samplers before sending them to an external laboratory for measurement. Presently, the environmental laboratory does not have to be housed in the PACB due to the background radiation. HP Laboratory: The objective of this laboratory is to analyse radioactive samples, in order to check compliancy with regulatory requirements and internal procedures. In order to reach these objectives, this laboratory is split in the dedicated following places: Radioactive sample preparation; Tritium analysis laboratory, Beta gamma counting laboratory. L. Perna Barcelona 27/11/

31 Process Control The Process Control includes equipment which are linked to specific ITER processes. These equipment are completely separated from the Health Physics System and they shall be managed by ITER operator. The items of equipment concerned are: Tritium HVAC/DS detectors which will be used for the isolation of HVAC and for the connection to the Detritiation System (safety confinement function, SIC 1); Tritium Port Cell detectors which will be used for cleaning the Port Cell by the Detriatiation System (SR). L. Perna Barcelona 27/11/

32 Process Control Tritium HVAC/DS (SIC 1) Tritium HVAC/DS detectors shall be used for the isolation of HVAC and for the connection to the Detritiation System (safety confinement function). In each confinement sector served by HVAC (class C2 II) in Tokamak & Hot Cell Facility complexes, the HVAC dampers shall be closed and Detritiation System shall start automatically operating, when tritium in air concentration reaches 10 8 Bq/m 3. This function shall be accomplished by HVAC trigger tritium detectors and this function is classified SIC 1. The diagram shows the architecture and the different systems included in this function. L. Perna Barcelona 27/11/

33 Process Control Tritium HVAC/DS (SIC 1) According to the ITER Plant Control Design Handbook for nuclear safety, systems classified SIC 1 have to apply: Single failure criterion (Redundancy criterion, Independence, Physical separation, Electrical isolation), Reliability criterion, Robustness criterion, Testability, maintainability criterion, Qualification criterion, Access criterion, Exchange of critical information criterion: SIC 1 system does not use networks for the exchange of critical information related to the execution of the safety function between components Redundant power supply L. Perna Barcelona 27/11/

34 Process Control T Port Cell (SR) Access to the VV ports is made via a number of Port Cells (46). These are dedicated confinement rooms and separated (via static & dynamic components) from the main gallery areas at each of the port levels: Lower, Equatorial and Upper Ports. The radiological conditions in these areas have to be checked in order to detect accident situations with releases of Tritium and to initiate corrective actions (to increase the renewal flow rate of DS for Port Pell cleaning) in case of tritium concentration exceeding a threshold. In order to avoid installing a tritium detector per Port Cell and to simplify the DS piping, Tritium concentration is checked per group of 6 Port Cells. L. Perna Barcelona 27/11/

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