- Email: [email protected]
Receiving inspection and tests of the ITER poloidal field #4 cryostat feed-through
Fusion Engineering and Design 146 (2019) 1620–1623
Contents lists available at ScienceDirect
Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes
Receiving inspection and tests of the ITER poloidal field #4 cryostat feedthrough
T
⁎
Frederic Villecrozea, , Jean Louis Bersierb, Theo Brillemana, Olivier Dumoulina, Chen-yu Gungb, Guillaume Jiolata, Yohanbhai Khristib, Thierry Lamirala, Antony Marianib, Laurent Nicolasa, Bertrand Pelusoa, Roland Piccinb, Eric Pignolya, Alexandre Torrea, Alexander Vostnerb, Lijun Wanb a b
DRF/IRFM, CEA Cadarache, St Paul lez Durance, France ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex, France
A R T I C LE I N FO
A B S T R A C T
Keywords: ITER Magnets MIFI Feeder Inspection
The ITER Magnets are in the procurement and assembly phases. During these phases, critical components need to be tested and assembly procedures need to be developed and qualified on mockups. To this end, ITER Organization (IO) and the Commissariat à l’Energie Atomique (CEA) have built up a support structure with space, expertise and equipment: MIFI – Magnet Infrastructure Facilities for ITER. In this framework, IO and CEA perform Receiving Inspection and Tests (RIT) on components delivered to IO by the Domestic Agencies (DA). RIT is a critical stage in the life process of components. These tests are meant to ensure the good quality of components and occur between the Factory Acceptance Test (performed before delivery to IO) and the Site Acceptance Tests that are performed after installation in the tokamak pit. The paper explains the RIT sequence managed on the Poloidal Field #4 Cryostat Feedthrough (PF4 CFT), the first ITER Magnets component to be delivered by a Domestic Agency to ITER Organization, and details leak tests, metrology tests and High Voltage tests performed.
1. Introduction Under the construction phase, ITER is now preparing for the arrival and installation of the first components. Some of them must be installed in the pit, taking into account constraints from construction schedule and before implementation of other components that will make impossible to remove them in case of a problem. This is the case of a subsystem in one of the thirty one feeders used to power the poloidal and toroidal superconductive coils. The PF4 CFT which is the acronym of Poloidal Field #4 Cryostat Feed-Through is the first and the most critical part of the PF4 feeder to be installed prior to the cryostat basement assembly. 2. The ITER magnet system and the feeders 2.1. General overview The ITER Magnets are the largest superconducting magnets ever built. A total of 18 toroidal field (TF) coils + 6 poloidal field (PF) coils
⁎
and a central solenoid (CS), all located inside the main cryostat, must be connected to the cryo system, power supply and control system outside the cryostat. These connections from inside to outside are realized by the feeders. They are the lifelines of the ITER magnet system. In total, 31 feeders [1] are distributed around the tokamak (Fig. 1): 9 for the toroidal field magnet system, 6 for the poloidal field magnet system, 6 for the central solenoid modules, 5 for the correction coil systems, 3 reserved exclusively for the supply of cryogens to the TF coil structure cooling systems and 2 for coil instrumentation. 2.2. The feeders: description Each feeder is around 40 m long and ∼50 t. Fig. 2 shows a generic feeder layout with identification of the different parts. As shown, the CFT makes the connection between the tokamak gallery and the internal cryostat. All the feeders penetrate the cryostat horizontally at base section and will be installed from the gallery side. The feeder for the PF4 penetrates the cryostat vertically. For this reason, the PF4 CFT has a
Corresponding author. E-mail address: [email protected] (F. Villecroze).
https://doi.org/10.1016/j.fusengdes.2019.03.002 Received 8 October 2018; Received in revised form 5 February 2019; Accepted 1 March 2019 Available online 29 March 2019 0920-3796/ © 2019 Elsevier B.V. All rights reserved.
Fusion Engineering and Design 146 (2019) 1620–1623
F. Villecroze, et al.
Fig. 1. Feeders around the ITER cryostat.
Fig. 4. Detail design of internal PF4 CFT.
3.3. Manufacturing and delivery The PF4 CFT is the first real magnet component manufactured by the Chinese Domestic Agency (CN-DA) and the first to be installed in the tokamak pit. It is a captive component, thus no possibility to repair it or to replace it once installed. On manufacturing site, the PF4 CFT has been fully instrumented and tested prior to its shipping. Specific procedures for HV (High Voltage) tests, leak tests, dimensional survey have been written. Tests have been completed and reports were filled. All those documents are attached to the PF4 CFT and are considered as the reference documents. Similar tests will be performed at MIFI [3] to manage the RIT (Receiving Inspection and Tests).
Fig. 2. Generic feeder layout.
different shape and must be installed prior, from inside the bio-shield, to the cryostat basement.
4. The RIT: receiving inspection & tests 4.1. Goal of the RIT
3. The PF4 CFT: a critical part of the feeders The goal of the RIT, managed after the shipping on delivery site at MIFI, is to verify and ensure that all critical functionality are preserved during the shipment and to check original data from the CN-DA. The RIT of the PF4 CFT is a very important phase during which 5 activities are carried out:
3.1. Presentation Designed for the poloidal field coil #4, the PF4 CFT connects the CTB and the ICF (see Fig. 3) through the ∼2 m thick concrete bio-shield (Fig. 2). The CFT is the bottleneck of the feeder, passing through the bio-shield and crossing the cryostat wall [2]. Fig. 3 gives an overview of the whole PF4 feeder.
• Transport, lifting, unpacking/repacking • Leak check (VD, VB, BB, He pipes) • Metrology (interface measurement…) • HV tests (insulation, continuity…) • Endoscopy
3.2. Details The PF4CFT weight ∼7 tons and is ∼7 m long, 4 m high. The external containment duct hosts a large vacuum duct (VD) inside of which are instrumentation ducts, busbars (BB) and cooling pipes are distributed. A vacuum barrier (VB) separates the vacuum in the cryostat and in the CTB, while a thermal shield cooled by 80 K He gas guaranties a perfect cooling of the PF4 CFT. Fig. 4 shows details of the internal PF4 CFT.
4.2. Management of the RIT To manage the progress of the tests, the MIP (Manufacture Inspection Plan) is the official document that describes, step by step, all the operation that must be carried out from the receiving of the component to its leaving. Following the MIP, it should help to perform all the tests or verifications avoiding risk of lack of information. 5. The PF4 CFT RIT The RIT of the PF4 CFT is divided in two main tasks: the preparatory work and then the testing. 5.1. Preparatory work Some requirements (procurement and installation of material) were mandatory by ITER to perform the RIT in safe and clean conditions. Other requirements as writing of safety documents were also required to guarantee the conformity with French regulation and with CEA rules. The main requirements were to delimit a specific area (Fig. 6) with limited access (interlock), to allow the access and work at the upper end of the component and to guarantee a clean and controlled ISO 9 class
Fig. 3. Complete PF4 feeder with PF4 CFT. 1621
Fusion Engineering and Design 146 (2019) 1620–1623
F. Villecroze, et al.
5.2. Testing
Fig. 5. a–b: Offloading and unpacking.
5.2.1. MIP of the PF4 CFT: presentation The MIP of the PF4 CFT is an official document, printed only in one copy on a colored page (thus avoiding copies) as requested by IO QA (Quality Assurance). It is managed and stored in the RIT area. At the end of the RIT, it will be uploaded on ITER IDM database and will be the reference document attesting of the complete achievement of the operations.
Fig. 6. Overview of the RIT area.
5.2.2. MIP of the PF4 CFT: details The MIP totalizes 29 critical operations. The IO RO (Responsible Officer) has originally proposed this list of operations and MIFI has been involved in the creation of this document. The relationship between IO and MIFI permitted to get an accurate document. First, the MIP must be reviewed by all parts and approved. The testing procedures must be written and approved before starting the experiments. In the RIT area, one folder was dedicated to procedures related to work ongoing and another one to procedures related to work finished. This guarantees a good proficiency of the process. For each sequence of the MIP, a responsible of the operation was assigned (IO, IO with support of MIFI, IO with subcontractor or MIFI). The achievement of the operation was validated by the responsible (date + signature) and by the witness if required (e.g. IO witnessed an operation carried out by MIFI). For some steps, a report was required and uploaded on IDM, the ITER database. 5.2.3. Metrology survey The main purpose of the MIFI survey was to repeat the Dimensional Inspection (DI), in accordance to the PF4-CFT Laser Tracker Measurement procedure, performed by the CN-DA, comparing the results after the final transportation to IO. Prior to the DI of the PF4 CFT an enhanced control network had been installed in order to allow further instrument positions. Temporary Target nests were required for changing the laser tracker position keeping the alignment. They were temporary glued to the surrounding stable surfaces, mainly floor and walls. These glued targets and all PF4-CFT fiducial targets were measured to create the fiducial network (Fig. 7a). To avoid any risk of variation between the PF4 CFT’s 3D reference, due to the possibility of the structure being deformed during transportation, each fiducial target nest was measured and compared to the CN-DA 3D reference value, verifying the reference ready for planned activities in MIFI. To ensure each fiducial target nest reference is securely fixed to the body of the PF4 CFT for final installation into the Tokamak Pit, a special fixture tool had been designed to drill and dowel each target nest, without introducing any variation to the original CNDA reference. All the operation of metrology were performed according to the approved procedure meeting the ITER QA requirements. Each cooling and instrumentation pipes were carefully measured and cut precisely (Fig. 7b), at their final interface, all within the stated tolerance of +/−5 mm. MIFI staff designed a tool to guarantee a perfect 90° cut, avoiding any stainless steel debris to fall inside the pipes. All measurements had been carried out on the PF4 CFT with IO’s certified class 2 portable Laser Tracker, Leica AT403.
air at both ends.
5.1.1. Preparation of the receiving component The lifting of the PF4 CFT into the RIT area in the test building and the unpacking were coordinated by MIFI. A special arrangement of the truck path was needed due to the dimension of the PF4 CFT shipping box. A 50 t mobile crane have been required to offload the PF4 CFT and its shipping frame (total weight of 16 t) from the truck in safe conditions (Fig. 5a). Prior to the offloading, trials had been done to validate the feasibility. The unpacking of the PF4 CFT required the use of a boom lift (Fig. 5b). The shipping frame will be re-used for the shipping of the PF4 CFT from MIFI RIT area to ITER Organization.
5.1.2. Area enclosure One of the main requirements was to manage the RIT in a dedicated area, with access restriction (property of IO). In this area were required utilities as standard electrical power, compressed air, good grounding point, wide space, access to the top of the PF4 CFT, guarantee of ISO 9 class of air at both sides of the component, possibility to use various gases. Fig. 6 shows the RIT area delimited by metal/glass fences with a large door for specific needs and with mainly the ISO 9 tents, the interlocked hall and the scaffolding.
5.1.3. ISO 9 air class spaces The control of the cleanness of the air at both ends of the PF4 CFT was requested, all along the RIT, 24 h/24. Specific ISO 9 tents were especially designed with movable roofs to permit lifting operation from above without changing the air quality inside the tents. Special carpets were installed in the RIT area (entrance and close to the upper tent) to catch, as much as possible, dust and others coming from the shoe’s soles. Each tent is equipped with 2 FFU (Fan Filter Unit) including a master filter and a control panel. Pre-filters are installed on the FFU to increase their lifetime. A permanent air flux of 0.38 ms−1 flows from top to bottom in each tent.
5.2.4. Leak tests The purpose of the leak test was to ensure that after the shipping, no damage occurred on internal components (pipes, bellows…). Thus, the vacuum duct (VD), the cooling pipes, the Busbars (BB) and the Vacuum Barrier (VB) were tested as described in the approved leak testing procedure. According to the existing standards [4], the leak test method was A2 for the Vacuum Duct/Vacuum barrier. They were evacuated and connected to the leak detector and the test areas were covered by a gas-tight enclosure filled with helium as a tracer gas. 1622
Fusion Engineering and Design 146 (2019) 1620–1623
F. Villecroze, et al.
Fig. 7. a–b: Reference network and interfaces measurement.
criteria was no breakdown & IR > 0.5 GΩ after a 10 min @ 15 kV DC. Because the Electrical tests were carried out at HV, a special attention was taken regarding the floating potential during the tests. All the passive structures and insulated objects in the test area were grounded. The setup is shown on Fig. 9. The test device was a MEGGER 1525. After this test, internal temperature sensors (Pt100) have been tested in accordance to the main requirements of a Rcable < 4.28 Ω/ 20 m and a Δtemp of +−2 °C between Pt100 and PF4 CFT metallic structure. Fluke 177 Digital multimeter and Agilent 34410A Digital Multimeter were used to perform the tests. 5.2.6. Internal visual inspection An internal visual inspection of the PF4 CFT was done at the end of the MIP as a last check before the closure of the duct and its preparation for installation in the pit. The endoscope was a General Electric Mentor Visual iQ Videoprobe.
Fig. 8. VB testing 1 bar at CTB side/pumping at ICF side.
6. Conclusion Fully tested in China before its shipping to France, the PF4 CFT has been once again verified at MIFI before its installation in the tokamak pit. The goal of this Receiving Inspection and Tests was to point critical issues and to make a feedback to the manufacturer in order to improve the life cycle of such component. No major issues were detected on the PF4 CFT. Nonetheless, the RIT has been a valuable step between the Factory Acceptance Tests (FAT) and the installation in the pit to correct minor defects and prepare the component for the installation. Preliminary checks or trials (e.g. the trial of the lifting tool) were fundamentals and necessary, avoiding potential future problems and saving time in the pit in the tokamak building.
Fig. 9. HV test setup on the PF4 CFT.
For the busbars and cooling pipes, the method was B2.They were pressurized (0.15 MPa) with tracer gas (helium) while the vacuum duct was evacuated and connected to the leak detector. The PF4 CFT internal pipes have been tested referring the procedure and as following: Vacuum Duct: vacuum leak test, BB and He pipes: pressure leak tests (leak check by He pressurization of the pipes at 0.3 MPa, VB: leak test with 0.1 MPa on CTB side and vacuum at ICF and vice versa. For example, the Fig. 8 illustrates the set-up for leak testing of the VB with 1 bar He at CTB side. Leak tests have been done with a Mass Spectrometer Leak Detector (Inficon UL 5000) and the acceptance leak rate was 1.10–9 Pa m3 s−1 (air equivalent) as given for Vacuum Quality Class 2.
Disclaimer The views and opinions expressed herein do not necessarily reflect those of the ITER Organization. Acknowledgments I acknowledge all the persons involved in this RIT for their amiability, availability and their professionalism. I would also like to thank T. Zhou who worked on the preparatory phase of this RIT. References [1] C.Y. Gung, et al., Progress in design, analysis, and manufacturing studies of the ITER feeders, IEEE TAS (June) (2012). [2] Y. Chen, ITER magnet feeder: design, manufacturing and integration, Plasma Sci. Technol. 17 (March (3)) (2015). [3] B. Peluso, et al., Magnet Infrastructure Facilities for ITER Description and Activities Overview, IEEE TAS (April) (2018). [4] EN 1779, Non-Destructive Testing, Leak Testing Criteria, December (1999).
5.2.5. High voltage tests As described in the approved DC testing procedure for ITER feeders, the aim of the HV test was to make sure that the Insulation Resistance (IR) of the BB was still higher than 0.5GΩ after shipping, lifting, leak tests and mechanical operations on the PF4 CFT. The acceptance 1623
Contents lists available at ScienceDirect
Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes
Receiving inspection and tests of the ITER poloidal field #4 cryostat feedthrough
T
⁎
Frederic Villecrozea, , Jean Louis Bersierb, Theo Brillemana, Olivier Dumoulina, Chen-yu Gungb, Guillaume Jiolata, Yohanbhai Khristib, Thierry Lamirala, Antony Marianib, Laurent Nicolasa, Bertrand Pelusoa, Roland Piccinb, Eric Pignolya, Alexandre Torrea, Alexander Vostnerb, Lijun Wanb a b
DRF/IRFM, CEA Cadarache, St Paul lez Durance, France ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex, France
A R T I C LE I N FO
A B S T R A C T
Keywords: ITER Magnets MIFI Feeder Inspection
The ITER Magnets are in the procurement and assembly phases. During these phases, critical components need to be tested and assembly procedures need to be developed and qualified on mockups. To this end, ITER Organization (IO) and the Commissariat à l’Energie Atomique (CEA) have built up a support structure with space, expertise and equipment: MIFI – Magnet Infrastructure Facilities for ITER. In this framework, IO and CEA perform Receiving Inspection and Tests (RIT) on components delivered to IO by the Domestic Agencies (DA). RIT is a critical stage in the life process of components. These tests are meant to ensure the good quality of components and occur between the Factory Acceptance Test (performed before delivery to IO) and the Site Acceptance Tests that are performed after installation in the tokamak pit. The paper explains the RIT sequence managed on the Poloidal Field #4 Cryostat Feedthrough (PF4 CFT), the first ITER Magnets component to be delivered by a Domestic Agency to ITER Organization, and details leak tests, metrology tests and High Voltage tests performed.
1. Introduction Under the construction phase, ITER is now preparing for the arrival and installation of the first components. Some of them must be installed in the pit, taking into account constraints from construction schedule and before implementation of other components that will make impossible to remove them in case of a problem. This is the case of a subsystem in one of the thirty one feeders used to power the poloidal and toroidal superconductive coils. The PF4 CFT which is the acronym of Poloidal Field #4 Cryostat Feed-Through is the first and the most critical part of the PF4 feeder to be installed prior to the cryostat basement assembly. 2. The ITER magnet system and the feeders 2.1. General overview The ITER Magnets are the largest superconducting magnets ever built. A total of 18 toroidal field (TF) coils + 6 poloidal field (PF) coils
⁎
and a central solenoid (CS), all located inside the main cryostat, must be connected to the cryo system, power supply and control system outside the cryostat. These connections from inside to outside are realized by the feeders. They are the lifelines of the ITER magnet system. In total, 31 feeders [1] are distributed around the tokamak (Fig. 1): 9 for the toroidal field magnet system, 6 for the poloidal field magnet system, 6 for the central solenoid modules, 5 for the correction coil systems, 3 reserved exclusively for the supply of cryogens to the TF coil structure cooling systems and 2 for coil instrumentation. 2.2. The feeders: description Each feeder is around 40 m long and ∼50 t. Fig. 2 shows a generic feeder layout with identification of the different parts. As shown, the CFT makes the connection between the tokamak gallery and the internal cryostat. All the feeders penetrate the cryostat horizontally at base section and will be installed from the gallery side. The feeder for the PF4 penetrates the cryostat vertically. For this reason, the PF4 CFT has a
Corresponding author. E-mail address: [email protected] (F. Villecroze).
https://doi.org/10.1016/j.fusengdes.2019.03.002 Received 8 October 2018; Received in revised form 5 February 2019; Accepted 1 March 2019 Available online 29 March 2019 0920-3796/ © 2019 Elsevier B.V. All rights reserved.
Fusion Engineering and Design 146 (2019) 1620–1623
F. Villecroze, et al.
Fig. 1. Feeders around the ITER cryostat.
Fig. 4. Detail design of internal PF4 CFT.
3.3. Manufacturing and delivery The PF4 CFT is the first real magnet component manufactured by the Chinese Domestic Agency (CN-DA) and the first to be installed in the tokamak pit. It is a captive component, thus no possibility to repair it or to replace it once installed. On manufacturing site, the PF4 CFT has been fully instrumented and tested prior to its shipping. Specific procedures for HV (High Voltage) tests, leak tests, dimensional survey have been written. Tests have been completed and reports were filled. All those documents are attached to the PF4 CFT and are considered as the reference documents. Similar tests will be performed at MIFI [3] to manage the RIT (Receiving Inspection and Tests).
Fig. 2. Generic feeder layout.
different shape and must be installed prior, from inside the bio-shield, to the cryostat basement.
4. The RIT: receiving inspection & tests 4.1. Goal of the RIT
3. The PF4 CFT: a critical part of the feeders The goal of the RIT, managed after the shipping on delivery site at MIFI, is to verify and ensure that all critical functionality are preserved during the shipment and to check original data from the CN-DA. The RIT of the PF4 CFT is a very important phase during which 5 activities are carried out:
3.1. Presentation Designed for the poloidal field coil #4, the PF4 CFT connects the CTB and the ICF (see Fig. 3) through the ∼2 m thick concrete bio-shield (Fig. 2). The CFT is the bottleneck of the feeder, passing through the bio-shield and crossing the cryostat wall [2]. Fig. 3 gives an overview of the whole PF4 feeder.
• Transport, lifting, unpacking/repacking • Leak check (VD, VB, BB, He pipes) • Metrology (interface measurement…) • HV tests (insulation, continuity…) • Endoscopy
3.2. Details The PF4CFT weight ∼7 tons and is ∼7 m long, 4 m high. The external containment duct hosts a large vacuum duct (VD) inside of which are instrumentation ducts, busbars (BB) and cooling pipes are distributed. A vacuum barrier (VB) separates the vacuum in the cryostat and in the CTB, while a thermal shield cooled by 80 K He gas guaranties a perfect cooling of the PF4 CFT. Fig. 4 shows details of the internal PF4 CFT.
4.2. Management of the RIT To manage the progress of the tests, the MIP (Manufacture Inspection Plan) is the official document that describes, step by step, all the operation that must be carried out from the receiving of the component to its leaving. Following the MIP, it should help to perform all the tests or verifications avoiding risk of lack of information. 5. The PF4 CFT RIT The RIT of the PF4 CFT is divided in two main tasks: the preparatory work and then the testing. 5.1. Preparatory work Some requirements (procurement and installation of material) were mandatory by ITER to perform the RIT in safe and clean conditions. Other requirements as writing of safety documents were also required to guarantee the conformity with French regulation and with CEA rules. The main requirements were to delimit a specific area (Fig. 6) with limited access (interlock), to allow the access and work at the upper end of the component and to guarantee a clean and controlled ISO 9 class
Fig. 3. Complete PF4 feeder with PF4 CFT. 1621
Fusion Engineering and Design 146 (2019) 1620–1623
F. Villecroze, et al.
5.2. Testing
Fig. 5. a–b: Offloading and unpacking.
5.2.1. MIP of the PF4 CFT: presentation The MIP of the PF4 CFT is an official document, printed only in one copy on a colored page (thus avoiding copies) as requested by IO QA (Quality Assurance). It is managed and stored in the RIT area. At the end of the RIT, it will be uploaded on ITER IDM database and will be the reference document attesting of the complete achievement of the operations.
Fig. 6. Overview of the RIT area.
5.2.2. MIP of the PF4 CFT: details The MIP totalizes 29 critical operations. The IO RO (Responsible Officer) has originally proposed this list of operations and MIFI has been involved in the creation of this document. The relationship between IO and MIFI permitted to get an accurate document. First, the MIP must be reviewed by all parts and approved. The testing procedures must be written and approved before starting the experiments. In the RIT area, one folder was dedicated to procedures related to work ongoing and another one to procedures related to work finished. This guarantees a good proficiency of the process. For each sequence of the MIP, a responsible of the operation was assigned (IO, IO with support of MIFI, IO with subcontractor or MIFI). The achievement of the operation was validated by the responsible (date + signature) and by the witness if required (e.g. IO witnessed an operation carried out by MIFI). For some steps, a report was required and uploaded on IDM, the ITER database. 5.2.3. Metrology survey The main purpose of the MIFI survey was to repeat the Dimensional Inspection (DI), in accordance to the PF4-CFT Laser Tracker Measurement procedure, performed by the CN-DA, comparing the results after the final transportation to IO. Prior to the DI of the PF4 CFT an enhanced control network had been installed in order to allow further instrument positions. Temporary Target nests were required for changing the laser tracker position keeping the alignment. They were temporary glued to the surrounding stable surfaces, mainly floor and walls. These glued targets and all PF4-CFT fiducial targets were measured to create the fiducial network (Fig. 7a). To avoid any risk of variation between the PF4 CFT’s 3D reference, due to the possibility of the structure being deformed during transportation, each fiducial target nest was measured and compared to the CN-DA 3D reference value, verifying the reference ready for planned activities in MIFI. To ensure each fiducial target nest reference is securely fixed to the body of the PF4 CFT for final installation into the Tokamak Pit, a special fixture tool had been designed to drill and dowel each target nest, without introducing any variation to the original CNDA reference. All the operation of metrology were performed according to the approved procedure meeting the ITER QA requirements. Each cooling and instrumentation pipes were carefully measured and cut precisely (Fig. 7b), at their final interface, all within the stated tolerance of +/−5 mm. MIFI staff designed a tool to guarantee a perfect 90° cut, avoiding any stainless steel debris to fall inside the pipes. All measurements had been carried out on the PF4 CFT with IO’s certified class 2 portable Laser Tracker, Leica AT403.
air at both ends.
5.1.1. Preparation of the receiving component The lifting of the PF4 CFT into the RIT area in the test building and the unpacking were coordinated by MIFI. A special arrangement of the truck path was needed due to the dimension of the PF4 CFT shipping box. A 50 t mobile crane have been required to offload the PF4 CFT and its shipping frame (total weight of 16 t) from the truck in safe conditions (Fig. 5a). Prior to the offloading, trials had been done to validate the feasibility. The unpacking of the PF4 CFT required the use of a boom lift (Fig. 5b). The shipping frame will be re-used for the shipping of the PF4 CFT from MIFI RIT area to ITER Organization.
5.1.2. Area enclosure One of the main requirements was to manage the RIT in a dedicated area, with access restriction (property of IO). In this area were required utilities as standard electrical power, compressed air, good grounding point, wide space, access to the top of the PF4 CFT, guarantee of ISO 9 class of air at both sides of the component, possibility to use various gases. Fig. 6 shows the RIT area delimited by metal/glass fences with a large door for specific needs and with mainly the ISO 9 tents, the interlocked hall and the scaffolding.
5.1.3. ISO 9 air class spaces The control of the cleanness of the air at both ends of the PF4 CFT was requested, all along the RIT, 24 h/24. Specific ISO 9 tents were especially designed with movable roofs to permit lifting operation from above without changing the air quality inside the tents. Special carpets were installed in the RIT area (entrance and close to the upper tent) to catch, as much as possible, dust and others coming from the shoe’s soles. Each tent is equipped with 2 FFU (Fan Filter Unit) including a master filter and a control panel. Pre-filters are installed on the FFU to increase their lifetime. A permanent air flux of 0.38 ms−1 flows from top to bottom in each tent.
5.2.4. Leak tests The purpose of the leak test was to ensure that after the shipping, no damage occurred on internal components (pipes, bellows…). Thus, the vacuum duct (VD), the cooling pipes, the Busbars (BB) and the Vacuum Barrier (VB) were tested as described in the approved leak testing procedure. According to the existing standards [4], the leak test method was A2 for the Vacuum Duct/Vacuum barrier. They were evacuated and connected to the leak detector and the test areas were covered by a gas-tight enclosure filled with helium as a tracer gas. 1622
Fusion Engineering and Design 146 (2019) 1620–1623
F. Villecroze, et al.
Fig. 7. a–b: Reference network and interfaces measurement.
criteria was no breakdown & IR > 0.5 GΩ after a 10 min @ 15 kV DC. Because the Electrical tests were carried out at HV, a special attention was taken regarding the floating potential during the tests. All the passive structures and insulated objects in the test area were grounded. The setup is shown on Fig. 9. The test device was a MEGGER 1525. After this test, internal temperature sensors (Pt100) have been tested in accordance to the main requirements of a Rcable < 4.28 Ω/ 20 m and a Δtemp of +−2 °C between Pt100 and PF4 CFT metallic structure. Fluke 177 Digital multimeter and Agilent 34410A Digital Multimeter were used to perform the tests. 5.2.6. Internal visual inspection An internal visual inspection of the PF4 CFT was done at the end of the MIP as a last check before the closure of the duct and its preparation for installation in the pit. The endoscope was a General Electric Mentor Visual iQ Videoprobe.
Fig. 8. VB testing 1 bar at CTB side/pumping at ICF side.
6. Conclusion Fully tested in China before its shipping to France, the PF4 CFT has been once again verified at MIFI before its installation in the tokamak pit. The goal of this Receiving Inspection and Tests was to point critical issues and to make a feedback to the manufacturer in order to improve the life cycle of such component. No major issues were detected on the PF4 CFT. Nonetheless, the RIT has been a valuable step between the Factory Acceptance Tests (FAT) and the installation in the pit to correct minor defects and prepare the component for the installation. Preliminary checks or trials (e.g. the trial of the lifting tool) were fundamentals and necessary, avoiding potential future problems and saving time in the pit in the tokamak building.
Fig. 9. HV test setup on the PF4 CFT.
For the busbars and cooling pipes, the method was B2.They were pressurized (0.15 MPa) with tracer gas (helium) while the vacuum duct was evacuated and connected to the leak detector. The PF4 CFT internal pipes have been tested referring the procedure and as following: Vacuum Duct: vacuum leak test, BB and He pipes: pressure leak tests (leak check by He pressurization of the pipes at 0.3 MPa, VB: leak test with 0.1 MPa on CTB side and vacuum at ICF and vice versa. For example, the Fig. 8 illustrates the set-up for leak testing of the VB with 1 bar He at CTB side. Leak tests have been done with a Mass Spectrometer Leak Detector (Inficon UL 5000) and the acceptance leak rate was 1.10–9 Pa m3 s−1 (air equivalent) as given for Vacuum Quality Class 2.
Disclaimer The views and opinions expressed herein do not necessarily reflect those of the ITER Organization. Acknowledgments I acknowledge all the persons involved in this RIT for their amiability, availability and their professionalism. I would also like to thank T. Zhou who worked on the preparatory phase of this RIT. References [1] C.Y. Gung, et al., Progress in design, analysis, and manufacturing studies of the ITER feeders, IEEE TAS (June) (2012). [2] Y. Chen, ITER magnet feeder: design, manufacturing and integration, Plasma Sci. Technol. 17 (March (3)) (2015). [3] B. Peluso, et al., Magnet Infrastructure Facilities for ITER Description and Activities Overview, IEEE TAS (April) (2018). [4] EN 1779, Non-Destructive Testing, Leak Testing Criteria, December (1999).
5.2.5. High voltage tests As described in the approved DC testing procedure for ITER feeders, the aim of the HV test was to make sure that the Insulation Resistance (IR) of the BB was still higher than 0.5GΩ after shipping, lifting, leak tests and mechanical operations on the PF4 CFT. The acceptance 1623