ALCEN's activities in

Inertial confinement

Within the framework of the French MegaJoule Laser (LMJ) program, ALSYOM was selected to design, manufacture and assemble the laser amplification section (with the exception of the amplifier itself) in 2003. This type of section, known as SAHA, comprises, for each of the 22 laser lines, a 105 metre-long, 100-tonne mechanical structure assembly containing opto-mechanical equipment controlling the propagation, shaping and optimization of laser beams.

After factory acceptance, all constituent parts and sub-assemblies were shipped to the LMJ site for final assembly. On-site works can basically be divided into two main phases associated with separate locations.

Cleaning and equipping of mechanical infrastructure

A dedicated workshop, PUPS (“Plateforme d’UltraPropreté SAHA”) belonging to CEA, has been fully defined and equipped with all required facilities by ALSYMEX according to specific constraints related to SAHA equipment manufacture and French ICPE regulations (air treatment, sewage management…). With a surface area of more than 13,000 m², it is operated by ALSYMEX and includes seven areas:

• Office zone
• Entrance deck
• Large dimension washing machines
• ISO8 and ISO5 integration halls
• Storage area
• Shipment deck
• Utilities area (air cleaning and sewage treatment) 

Once shipped to the PUPS, the mechanical structures are cleaned according to ISO5 (inner surfaces) and ISO8 (outer surfaces) requirements. Geometrical characterization, using laser trackers, and, whenever required, vacuum tests are then performed in the integration hall. 

At the same time, opto-mechanical systems, fully assembled in the Tarbes ISO5 clean room, are shipped to the same location for final integration, within ISO5 moveable zips, inside the mechanical structures. Final characterization of the fully equipped systems is done prior to transport on specially designed ISO8 vehicles to the dedicated LMJ laser hall. 

Final assembly and integration of the complete SAHA

Operations mostly included handling of the equipped structures and assembly of the complete 100 m amplifying sections in the ISO8 laser halls. Final acceptance was done in conjunction with the customer by simulating the propagation of a laser beam through the entire line.

All of this work was performed by subcontractors under the supervision and responsibility of ALSYMEX and according to the customer’s safety and operating regulations: The LMJ has recently been integrated within the CEA CESTA site, classified as an INBS (Installation Nucléaire de Base Secrète, or Secret Basic Nuclear Facility) according to French Regulations.

At the current time, 17 lines have been fully integrated (3 laser halls completed).

All together, the work performed at the PUPS and the LMJ laser halls involved a team of 35 staff members (20 ALSYOM permanent employees and 15 sub-contractor employees).

Achieving the requested transmission performance levels for all the optical components of the LMJ required a special coating technique to be used. This technique, called Sol Gel, has been specifically developed by experts at the CEA. All LMJ optical components must be treated using this technique prior to installation on the machine, as well as regularly during operation, as the coating has a limited lifetime.

Having industrialized and manufactured some of the coating tools, ALSYMEX was awarded a multi-year framework contract to operate and maintain the Sol Gel facility located in the vicinity of the LMJ building in 2011.

In addition to coating operations, work performed at the Sol Gel facility included:

• Upgrading laboratory technology into an industrial process
• Facility management, including compliance with French safety requirements

The Sol Gel facility is classified as an ICPE according to French regulations. This involves commitment and the obligation to fulfil requirements relating to the environment and, in particular, to ensure traceability of the various chemical products and to oversee and/or monitor the disposal of chemical waste materials.

Since certain areas of the building are also classified as ATEX facilities (explosive atmospheres), ALSYMEX had to implement collective and/or individual protection systems and procedures to guarantee the safety of the process for people working at the facility.

The transfer of technology from CEA to ALSYMEX took one year and led to the qualification of 5 different processes using two types of coatings. Since mid 2012, business has been growing by 50 % per year, in line with the customer expectations. At the current time, 7 members of staff are continuously working on this project, a capacity which can easily be increased to 15 staff members to handle full capacity.

ALSYMEX oversees the maintenance of all machinery directly involved in the coating process and manages subcontractors for building and clean-room maintenance.

Prior to the LMJ, CEA decided to design and build a demonstrator facility (LIL) in order to:

• Validate the expected performance levels of the LMJ
• Define the operational organization
• Train staff

The “LIL” was in operation from 2002 to the beginning of 2014 and comprised:

• A laser chain, a full-scale prototype of one of the 22 LMJ laser lines. This chain enabled optimization of the overall laser chain design and manufacture prior to its implementation on the LMJ.
• An experimental vacuum chamber (4.5 m diameter – 17 tonnes) equipped with a target and various measurement and diagnostics devices.

In 2003, ALSYMEX was awarded a 10-year contract for the deployment of operational maintenance of the entire facility under CEA management as per CEA quality, safety and environmental regulations, and, secondly, for actual completion of maintenance on the optical, vacuum and high-voltage systems of the laser line.

The activities, conducted in a facility dedicated to that purpose in the vicinity of the LIL building, varied over time and depended on actual customer requirements. It involved a core team of 10 staff members (SEIV employees) which was increased to 25 staff members during shutdown periods (twice a year).

The first stage of the project was mainly dedicated to “maintenance engineering”:

• Re-engineering of the different components and systems
• Elaboration of the maintenance schedule and documents as per CEA’s management organization and quality, safety and environmental regulations
• Drafting of technical instructions
• Planning and operational coordination

These activities were followed by actual maintenance operations and concluded, in 2014, with the dismantling of the LIL main assembly:

• Maintenance of opto-mechanical systems, in ISO8 to ISO4 clean rooms belonging to CEA
• Maintenance of vacuum systems (from 10-2 to 10-6 MPa) in laser mechanical structures and the experimental chamber
• Maintenance of high voltage connectors between the power supply and laser lines (energy bench)
• Definition and use of the proper tools and control/command systems to cover maintenance operations
• Use and technical management of a steam generator for the clean-room washing machine.

XFEL is a research facility under construction in Hamburg. It will generate extremely intense X-ray flashes (109 times stronger than the best conventional sources). To achieve this, bunches of electrons are accelerated to high energies and then directed through special magnet arrangements. The total length of the facility is 3.4 km, including a 2.1 km accelerator consisting of 800 superconducting RF cavities, grouped into 100 cryomodules.

CEA is responsible for cryomodule assembly. Major components (cavities, couplers, vacuum vessels, thermal shields), supplied by various partners, are assembled into cryomodules at a dedicated facility built for this type of work in Saclay (France). ALSYMEX has been awarded the contract to operate this facility and to manufacture the modules following procedures defined by CEA and DESY (Hamburg).

Initial operations in an ISO4 clean room include the assembly of RF coupler sections and cavities and assembly of strings of 8 cavities.

Strings are then laser tracker-aligned and fixed on the cold mass outside of the clean room. Thermal screens are welded prior to insertion of the complete system inside the cryostat.

Coupler warm sections, pumping lines and current feed-throughs are mounted and/or welded. Lastly, vacuum, RF and electrical tests are performed before closing under nitrogen and shipment to Hamburg.

Main characteristics of the cryomodules

• Dimensions: 12 m long × 1 m in diameter
• Weight: 7 tonnes
• Ultimate operating pressure: 10^-4 Pa
• RF cavities cooled by liquid helium (2 K) – Operating pressure of 0.12 MPa
• Thermal shields at 8 K and 80 K

FMC Technologies manufactures marine loading arms for the transfer of oil and liquid natural gas between ships and jetties. The arm is remotely moved to be connected to the ship interface using a clamping system (coupler). It then controls product transfer while following the ship's motion, ensuring safety by surveying and controlling risks such as collision or pullout between arm, jetty and ship. 

In addition to the supply of key parts of the arm, such as the coupler and emergency decoupling valve, ALSYMEX is in charge of the overall design, manufacture and testing of the safety control system up to SIL3.

Work is performed on the basis of a functional analysis defined by the customer and local regulatory rules. 

Main characteristics of the control system 

• Security Integrity Level (SIL) for electrical installations, sensors, actuators, Programmable Logic Controllers (PLC)
• ATEX (explosive) environments 
• Redundancy of safety PLCs (Siemens FH400, Rockwell Triconex), power supplies, and possibly of inputs and outputs 
• 3  level architecture: 

1. PLC and supervision systems 
2. remote controllers for inputs/outputs
3. sensors and actuators, using Intrinsically safe barriers for ATEX safety conditions

• Wireless remote used for manipulation of the arm by an operator
• Field and control room supervision, communication through ASCII, modbus, profibus, fieldbus, Ethernet, USB, optical fibber, wired and wireless, 
• Positioning Monitoring System (PMS) for monitoring the arm position in 3D
• Supervision on Siemens WINCC, with HMI for explosion-proof areas, Industrial PC and/or Touchscreen PC 
• Manufacturing of explosion-proof and PLC cabinets
• Factory tests
• On-site (worldwide) installation and commissioning

Oil and gas extraction in deeper waters and hazardous areas requires ships with more product lines and quick and safe disconnection capabilities in case of danger.

SBM Offshore has recognized expertise in connection systems and has developed a new system compatible with such constraints, ALSYMEX was tasked with the development of the overall control system.

The first step of the program consisted in the development of an initial locking device and control system, without constraints associated with explosive atmospheres. This was followed by the manufacture of a complete system including the command & control system. The architecture covered all environmental constraints: explosive atmospheres and subsea operation. The first ship equipped with such a system was tested in a yard in 2015. Final certification is underway in the Gulf of Mexico.

Main characteristics of the control system

• SIL3 safety system
• HIMA PLC-based 
• Win CC supervision 
• Ship control room communications
• Manufacture of the PLC cabinet
• Factory tests
• On-site installation and commissioning
• Safety tests performed by ALSYMEX’s TUV-certified Functional Safety Engineers 

ALSYMEX develops optimized presses for radioactive powders with integrated handling capabilities and with limited numbers of parts inside glove handling cabinets.

Based on specific customer requirements, ALSYMEX presses incorporate nuclear safety standards both for mechanical parts and materials, and for the command & control system in order to ensure safe confinement.

The command & control system includes a Human-Machine Interface (HMI) and supervision systems allowing for the surveillance and recording of process cycles.

Main characteristics of the control system

• SIL2 safety systems
• Siemens PLC 
• Win CC supervision 
• Higher level communication
• Manufacturing of the PLC cabinet
• Definition of the ventilation process
• Implementation of process regulation
• Factory tests
• On-site (worldwide) installation and commissioning

ALSOLEN, a subsidiary of ALCEN, has developed a thermodynamic solar plant using Fresnel mirror technology, especially designed for decentralized electricity grids (www.alsolen-alcen.com).

This development work was conducted within the framework of a collaboration between several ALCEN subsidiaries, including ALSYMEX, which was in charge of the structure and mirror rotation system (design, manufacture and on-site assembly), as well as the plant command & control system, including management of mirror positioning, fluid loops, energy production and storage, maintenance, tracking of sun position, safety management and the choice of sensors and actuators.

Main characteristics of the system

• SIL2 safety systems
• Process regulation loop
• Solar tracking algorithm
• S7-300 Siemens PLC
• Win CC supervision 
• Specific software development method based on CEA’s STIC specifications and libraries
• Plant control room
• Manufacturing of the PLC cabinet
• Factory tests
• On-site installation and commissioning
• Safety tests performed by ALSYMEX’s TUV-certified Functional safety Engineers 

Within the framework of the French MegaJoule Laser program, cryogenic targets for use on the target structure must be characterized at temperatures below 20 K. A dedicated cryostat has been developed for that purpose and to:

• Characterize temperature sensors
• Control the helium structure leak tightness
• Characterize the targets for specific studies

Main characteristics of the cryostat

• 1 meter long and 660 mm diameter vacuum chamber
• 10^-6 mbar operating pressure
• 700 mm long and 450 mm diameter 60 K screen made out of gold plated Oxygen Free Copper
• Integration of a cold head (pulse tube) for cooling down to 4 K
• Main support with 10 K screens
• Integration plates for targets
• Guide system for target insertion

In parallel with the first cryostat, IRELEC was in charge of the design and manufacture of an additional test cryostat used for the generation of solid ice pellets and their projection at several thousand of m/s (high velocity impact study).

Operating between -50°C and -10°C, this cryostat is dedicated to pellet shaping and analysis of pellet behaviour on acceleration up to 107 m.s^-2.

Main characteristics of the cryostat

• Two-stage injector
• 10^-4 mbar operating pressure
• 2 mm diameter cell for pellet shaping
• A launching tube and an experiment chamber, including a target and a high velocity camera

Cryogenic pumps have been developed to pump gases out of the ITER torus by adsorption on activated charcoal cooled to a temperature around 4.5 K. The cryogenic circuit of the coated surface is cooled by forced flow of supercritical helium. Protection of coated surfaces against heat loads is achieved by surrounding them with a thermal shield cooled by a forced flow of gaseous helium.

The cryogenic circuits are incorporated in a pump casing with an 800 mm diameter inlet valve to separate the pump from the torus, allowing for regeneration by heating the charcoal without interrupting plasma operation. The valve is controlled by an actuator. The position of the valve head enables throttling of the throughput to the eight cryopumps used in ITER.

In partnership with RI-Research Instruments from Germany, ALSYMEX has been awarded the contract to manufacture the pre-production cryogenic pump by F4E.

ALSYMEX‘s share of work includes: 

• Manufacture and assembly of the Pump Plug and associated flanges, including dimensional and leak tests
• Manufacture of the Housing Sub-Assembly, including dimensional and leak tests
• Manufacture and testing of the valve shaft, head and stem assembly

The various sub-assemblies are currently being manufactured. Final assembly of the pump is expected by mid 2017 for certification tests to be performed at the Karlsruhe Institute of Technology before the end of the year.

Main characteristics of the cryogenic pump

• Dimensions: 3.5 m long – 1.8 m diameter
• Weight: 8 tonnes
• Ultimate operating pressure: 10^-7 Pa
• Charcoal cooling: 0.4 MPa pressure, 4.3 K inlet temperature, 4.8 K outlet temperature
• Shield cooling: 1.8 MPa pressure, 80 K inlet temperature, 90 K outlet temperature
• Variable-stroke actuator up to 470 mm

XFEL is a research facility under construction in Hamburg. It will generate extremely intense X-ray flashes (109 times stronger than the best conventional sources). To achieve this, bunches of electrons are accelerated to high energies and then directed through special magnet arrangements. The total length of the facility is 3.4km, including a 2.1 km accelerator consisting of 800 superconducting RF cavities, grouped into 100 cryomodules.

CEA is responsible for cryomodule assembly. Major components (cavities, couplers, vacuum vessels, thermal shields), supplied by various partners, are assembled into cryomodules at a dedicated facility built for this type of work in Saclay (France). Alsyom has been awarded the contract to operate this facility and to manufacture the modules following procedures defined by CEA and DESY (Hamburg).

Initial operations in an ISO4 clean room include the assembly of RF coupler sections and cavities and assembly of strings of 8 cavities.

Strings are then laser tracker-aligned and fixed on the cold mass outside of the clean room. Thermal screens are welded prior to insertion of the complete system inside the cryostat.

Coupler warm sections, pumping lines and current feed-throughs are mounted and/or welded. Lastly, vacuum, RF and electrical tests are performed before closing under nitrogen and shipment to Hamburg.

Main characteristics of the cryomodules

• Dimensions: 12 m long × 1 m diameter
• Weight: 7 tonnes
• Ultimate operating pressure: 10^-4 Pa
• RF cavities cooled by liquid helium (2 K) – Operating pressure of 0.12 MPa
• Thermal shields at 8 K and 80 K

FMC Technologies manufactures marine loading arms for the transfer of oil and liquid natural gas between ships and jetties. The arm is remotely moved for connection to the ship interface using a clamping system (coupler). Product transfer is then controlled while following the ship's movements, safety is ensured by surveying and controlling risks of collision or pullout between the arm, jetty and ship.

In addition to the overall design, manufacture and testing of the safety control system, ALSYMEX is in charge of the supply of key parts of the arm, such as the coupler and emergency decoupling valve.

The scope of the design phase includes an industrialization study based on a preliminary customer design, a manufacturability study and cost optimization involving the re-design of sub-assemblies.

The manufacturing phase covers sub-assemblies located at the end of the arm, coupling and guidance systems, as well as emergency decoupling double valves.

Main characteristics of the components

• Use of hydraulic power to allow for displacement and coupling of arms
• Overall mechanical assembly up to 6 meters in height, 0.5 m diameter
• Design and Materials certified for operation down to 77 K
• Specific constraints related to explosive environments
• Work performed according to offshore standards

Prior to the LMJ, CEA decided to design and build a demonstrator facility (LIL) in order to:

• Validate the expected performance of the LMJ
• Define the operational organization
• Train staff

The “LIL”, was in operation from 2002 to the beginning of 2014 and comprised:

• A laser chain, a full scale prototype of one of the 22 LMJ laser lines. This chain enabled optimization of the overall laser chain design and manufacture prior to its implementation on the LMJ.
• An experimental vacuum chamber (4.5 m diameter – 17 tonnes) equipped with a target and various measurement and diagnostics devices.

Among these systems, plasma diagnostics enabled observation of the target behaviour during interaction with the laser beams (time scale about 1 to 15 nanoseconds).

These were mainly imaging and spectroscopy devices that provided information about the spatial, temporal and spectral evolution of the interaction based on emissions (visible, UV, X-ray, gamma and neutrons) from the target.

The main diagnostics functions included:

• Raman-Brillouin spectrometer with spatial resolution in retro-diffusion mode
• Diffused laser energy with time resolution
• Measurement of transmitted energy
• Hard X-ray 2D imaging
• Hard X-ray imaging with slit scan camera
• Hard X-ray multi-imaging
• Soft X-ray imaging with slit scan camera
• Soft X-ray multi-imaging
• Large bandwidth X-ray spectrometry with time resolution
• High resolution spectrometry (2 to 5 keV) with slit scan camera

IRELEC was tasked with the development of a High resolution multi-KirkPatrick-Baez microscope and a 1.1m² ellipsoidal diffuser made out of Spectralon^® (fluoropolymer).

As part of the French MegaJoule Laser (LMJ) program, ALSYMEX manufactured a reduced-scale X-ray imaging system prototype comprising:

• a mechanical structure for the toroidal mirror 
• an input lens assembly
• a screen support
• a dismountable plane mirror support
• a diagnostic insertion device sub-assembly
• a test support
• optical components: three mirrors and one lens
• a rod support

The work performed for this project has enabled it to:

• achieve, using a purely mechanical assembly, proper collimation of a laser beam
• qualify a material with mechanical properties compatible with high power lasers and allowing for safe and reliable operation of the collimator in the LMJ’s severe environment, as well as its machining procedures
• validate the geometry of the system with respect to the laser beam diameter, as well as processes regarding the performance and stability of the collimator
• qualify assembly and integration procedures in an ISO8 clean environment

The APOLLO system, entirely developed by LERITY, is perfectly suited to ionizing environments.

This compact and ruggedized system is resistant to radiation in excess of 100 Mrad (1 Mrad/hour), ensuring long-term operating capabilities in radioactive environments. Its waterproof camera module is linked to the control unit module by a radiation-resistant cable specifically developed for APOLLO.

LERITY supplied the entire optical chain, as well as networking capabilities and image replay functions. The system is compatible with underwater operation and resistant to pressures of up to 6 bar.

Potential applications include surveillance in ionizing environments, deep-water surveillance, water and sewage pipe inspection.

PMB develops and supplies a wide range of X-Ray components such as:

X-ray tubes

Used in various applications such as medicine, scientific research, characterization, and non-destructive inspection, these consist of three fundamental elements: the cathode, which generates the electrons, the anode, which is hit by the electrons to create the x-rays, and the cover, which maintains the high vacuum level necessary for proper operation.

PMB uses its full knowledge base of materials (common metals such as stainless steel and exotic ones such as beryllium, as well as ceramics) and technologies (forming, sintering, brazing, soldering, heat treatment, ultra-clean cleaning) to meet the stringent requirements of this field of application.

PMB supplies the key sub-assemblies, as well as those which comprise the x-ray tube.

Ionization chambers

These types of chambers are used in radiotherapy and in diagnostic radiology to determine the X-ray dose.

Many technologies are available: metal-coated and bonded Kapton, metal-coated and brazed aluminium oxide, and aluminium/alumina sandwiches.

PMB ionization chambers can operate in different atmospheres such as air or nitrogen.

Conversion targets

Allowing for the conversion of electron beams to X-rays, they are generally cooled by a special water circuit and are made of tungsten brazed to a copper cover, ensuring good heat evacuation.

The thickness of the tungsten target depends on the energy of the incident beam.

PMB develops special interfaces allowing for targets to be incorporated into any machine.

The MegaJoule Laser (LMJ) is one of the most important tools used by the French Simulation program initiated by the CEA in 1996 to perpetuate the French nuclear deterrent following the decision to stop nuclear tests in the Pacific Ocean. The purpose of the program is to simulate nuclear fusion conditions using 176 laser beams which concentrate their power on a target a few millimetres in diameter located at the center of a large diameter spherical chamber.

To ensure its protection, the inner surface of the experimental chamber is covered by aluminum protection panels, allowing to catch products generated by the target implosion to the furthest extent possible. Such panels are regularly dismounted to be cleaned.

The LMJ experimental chamber is equipped with a total number of 249 panels of 26 different types and gathered on three different areas: bottom, top and equatorial parts of the sphere. Each of them consists in a few-millimeter vacuum tight welded box, filled with welded fins. The assembly is completed by a special system allowing to fix it on (and remove it from) the inner wall of the chamber.

Based on a design provided by AREVA, ALSYMEX has been in charge of the supply of all the LMJ protection panels. Work performed included:

• Realization of the manufacturing drawings and production and control files
• Design and manufacture of the necessary tooling
• Machining and welding of the constituent sub-assemblies
• Functional tests
• ISO8 cleaning
• Supply of associated documentation
• Packing and transport to the CEA LMJ site

The MegaJoule Laser (LMJ) is one of the most important tools used by the French Simulation program initiated by the CEA in 1996 to perpetuate the French nuclear deterrent following the decision to stop nuclear tests in the Pacific Ocean. The purpose of the program is to simulate nuclear fusion conditions using 176 laser beams, gathered in 44 quadruplets, which concentrate their power on a target a few millimetres in diameter

Each of these quadruplets includes, at the end of the laser chain, a Focusing and Frequency Conversion System (SCF), equipped with four different types of replaceable optical units (16 units per SCF). LRA and KDP are optical systems integrated into motorized frames enabling fine tuning on site. R1w and R3w networks are manually adjusted in advance thanks to specific means integrated into their frames.

Design of the complete SCF and of the optical units was performed by CEA in collaboration with an industrial partner, ALSYMEX, having been awarded the manufacturing contract for the complete set of replaceable optical units. For each of them, the company is responsible for:

• Manufacturing and supplying all constituent parts, except optics directly supplied by the customer
• Cleaning all parts
• Assembly in ISO 5 clean room, including the frame’s mechanical parts and components, bonding of small size optical parts (absorbers), integration of the customer-provided optics
• Tuning, in accordance with procedures and benches defined and provided by CEA
• Final acceptance

Within the framework of the French MegaJoule Laser program, ALSYMEX has been awarded a contract for the design and manufacture of three glove boxes to be installed in the CEA CESTA premises. 

Used to unload, check, and possibly decontaminate films prior to analysis, they were qualified on a cold platform prior to installation at the premises.

Main characteristics of the glove boxes

• Dimensions: 2 m height × 1.8 m length,
• Class 2 ISO10648-2 standard glove boxes
• Made entirely out of stainless steel
• Sheet metal bending technology
• Definition and control of ventilation

In collaboration with CEA DEN / Marcoule, ALSYMEX developed and co-patented the first electromechanical press producing 10 tonnes of pressure for operation in highly radioactive environments, for the remote production of fuel pellets based on minor actinides.

Based on a joint development involving 3D design, 3D simulation, virtual reality testing and cold testing on a dedicated platform equipped with remotely operated manipulators, the product was successfully qualified without the need for design modifications.

Initial entry into service planned for 2017.

Main characteristics of the hot cell

• Dimensions: 1m height – 1.3 m diameter
• Weight: 650 kg
• 10 tonnes pressure capacity
• Fully automated production, up to 3 pellets per minutes
• Controlled process to produce near net-shaped pellets (diametric tolerance of 12 µm)
• Made entirely out of stainless steel
• Remote handling for operation, assembly, disassembly and maintenance

To improve nuclear power plant safety and improve knowledge of fuel behaviour in normal use and following accidents, the LECA-SQTAR hot cell laboratory located in Cadarache can handle irradiated fuel rods and open them in order to access fuel to analyse its evolution under irradiation.

ALSYMEX has designed and manufactured special tools dedicated to these types of hot cells including a bench for cutting and crimping rods.

After qualification on a cold platform, it has been in operation in the hot cell since 2015.

Main characteristics of the bench

• Dimensions: 1m in height – 1.5 m in length
• One cutting and one crimping stand
• Made entirely out of stainless steel 
• Remote handling for operation and maintenance

The ASTRID project is the design of a French prototype for GENERATION IV sodium cooled fast reactors and therefore needed to overcome the challenges associated with the qualification of innovative components and materials.

Given its role as an experimental facility for fast reactor deployment, ASTRID will be equipped with a set of hot cells. The French company ALSYMEX, a subsidiary of the ALCEN group, has been in charge of the overall preliminary design of the hot cell in conjunction with CEA, for the 4th generation reactor, since 2013 .

The main purpose of the ASTRID hot cells is to perform Non-Destructive Examinations (NDE, such as visual inspection, 3D X-ray tomography, dimensional inspection, eddy current testing) on the spent core sub-assemblies and fuel pins to verify post-irradiated fuel behaviour. To extract the latter from the sub-assemblies, a dismantling unit is planned for the facility.

A brief description of the components and capabilities of the ASTRID hot cell facility: 

• The facility includes a main cell, where the NDE equipment is installed, the lower cells with the dismantling machine and 3D X-ray scanner device and, lastly, the upper cell, which serves as an airlock for handling functions. 
• The ASTRID hot cells will feature remote operation of NDE equipment, e.g. new generation manipulators with an electrical master arm using haptic technology.
• This design aims to minimize of the use of massive and expensive lead windows, to increase handling capabilities and to improve operator ergonomics.

The MegaJoule Laser (LMJ) is one of the most important tools used by the French Simulation program initiated by the CEA in 1996 to perpetuate the French nuclear deterrent following the decision to stop nuclear tests in the Pacific Ocean. The purpose of the program is to simulate nuclear fusion conditions using 176 laser beams (22 lines of 8 beams) which concentrate their power on a target a few millimetres in diameter.

After having been successfully involved in the MegaJoule Laser prototype (LIL), ALSYMEX was selected in 2003 to design, manufacture, assemble and install the laser amplification section on site (excluding the amplifier itself). The section, called SAHA, consists, for each of the 22 laser lines, of a 105-metre long, 100-tonne mechanical structure assembly containing opto-mechanical systems (OMS) enabling the propagation, shaping and optimization of the laser beams. Mechanical structure inner volumes as well as OMS were designed for compatibility with ISO5 cleanliness standards, with some of them also having a vacuum tightness (10-6 mbar).

Moreover, and due to the vicinity of the experimental hall, some components complied with nuclear standards: low cobalt rated material (stainless steel), EMC robustness…

Several motorized mechanisms, enabling each of the beams to be directed onto the target with a precision of 5 hundredths of a millimetre after a 400 m long trip, were also developed: sensors, actuators, specific electrical cables…

Finally, the SAHA consists of a range of thirty different types of highly accurate and large mechanical structures and the same amount of opto-mechanical systems.

In parallel to this design work, a dedicated plant was built, from 2004 to 2006, for the machining and assembly of all components and systems.

A total of 660 stainless steel structures were manufactured between 2006 and 2010, with an average annual production volume of 133 units. Such a result was achieved by implementing work for both the machining and welding workshops in two shifts: 40 to 50 people depending on the period. The total amount of raw material which had to be procured to manufacture such units was in the range of 2200 tons and 3 major suppliers were involved (raw material, machining of single parts, assembly of specific pieces).

The primary features of the manufactured structures are as follows:

• Large dimensions: up to 10 m long, 2.5 m high, 2 m wide
• Weight up to 10 tonnes
• Accuracy 1/10° on 10 m length
• Cleanliness ISO 5 and ISO 8
• Vacuum (operational: 10-⁴ Pa ; test conditions: 10^-6 Pa)

Once factory acceptance tested with the customer was complete, mechanical structures were delivered to a dedicated workshop, located in the vicinity of the LMJ building, property of CEA and operated by ALSYMEX (called PUPS), for cleaning and assembly, prior to installation in the LMJ laser halls.

Manufacturing and assembly at the Tarbes facility (temperature-controlled machining workshop and purpose-built ISO 5 to ISO 8 clean rooms) of the opto-mechanical systems started approximately at the same time and is still ongoing. Once factory acceptance tested, OMS are shipped to PUPS where they are inserted inside the mechanical structures. The complete assemblies are then shipped to one of the four LMJ laser halls for final integration into the laser chain.

Taking advantage of this unique facility, CEA and the French “Region Aquitaine” have decided to couple an additional high power laser line to the LMJ to demonstrate the potential of the inertial fusion as an energy source. Benefiting from its experience with the LMJ SAHA, ALSYMEX was awarded a contract for the design, manufacture and on-site integration of the laser amplification line in 2008.

It consists of an assembly of twenty stainless steel mechanical structures including opto-mechanical components enabling the propagation, shaping and optimization of the laser beam. All mechanical structures have a cylindrical shape. Inner volumes, as well as the opto-mechanical sub-assemblies, had to be designed and manufactured to be compatible with ISO5 cleanliness standards and to operate under vacuum (10^-4 Pa). Among such structures are the following:

• 5 are 6 metres long with a diameter of 720 millimetres
• 1 is 4.8 metres long with a diameter of 720 millimetres
• 1 is 6.8 metres long with a diameter of 720 millimetres
• 1 is 7 metres long with a diameter of 720 millimetres
• 1 is 7 metres long, 2 metres wide and 2.9 m high
• 1 is 8 metres long, 1 metre wide and 0.9 m high

They were made out of plates rolled and mechanically welded over the length. Flanges on both sides were then machined one with respect to the other to reach the required constraints of flatness and parallelism: precision achieved was superior to 0.1 mm. After manufacturing, structures were shipped to a dedicated workshop (PUPS), located in the vicinity of the LMJ facility, property of CEA and operated by ALSYMEX, for final cleaning to comply with ISO standards.

At the same time, opto-mechanical sub-assemblies were manufactured and assembled in the ALSYMEX temperature-controlled workshop and clean room located in Tarbes, prior to shipment to PUPS where they were integrated into the mechanical structures.

Complete assemblies were then handled and moved to the LMJ laser hall for final assembly.

The MegaJoule Laser (LMJ) is one of the most important tools used by the French Simulation program initiated by the CEA in 1996 to perpetuate the French nuclear deterrent following the decision to stop nuclear tests in the Pacific Ocean. The purpose of the program is to simulate nuclear fusion conditions using 176 laser beams which concentrate their power on a target a few millimetres in diameter. The LMJ is composed of 22 lines of 8 laser beams each.

CEA commissioned CILAS for the Design, Manufacturing and On-Site Integration of the complete laser amplifiers (mechanical enclosures and opto-mechanical systems). Following a prototyping phase, CILAS decided to subcontract the final industrialization and manufacturing of 42 mechanical enclosures to ALSYMEX.

These enclosures consist of stainless steel mechanical structures which integrate several opto-mechanical components (neodine doped optical plates) enabling the amplification of the laser beam. They are plane-parallel shaped with a rectangular cross-section (8 m long × 2.9 m high × 2 m wide). Inner volumes have to be ISO6 cleanliness compatible (ISO8 for outer surfaces). Enclosures are made of 4 different sub-assemblies welded together:

• 2 lateral panels, each of them consisting of 2 thin plates welded together with inner stiffener spacers
• 2 U-shape flanges, each of them consisting of welded plates
• 1 lower base structure, consisting of 2 longitudinal EBW structures assembled with transverse stiffeners
• 1 higher structure, consisting of 5 square section tubes welded together, and machined in order to enable air flow during operation

Once these structures are assembled together, final machining is performed to achieve the external mechanical dimensional and geometrical requirements (accuracy around 1/10° mm on an 8 metre length). Enclosures are then polished so that surfaces are compatible with cleanliness requirements, prior to delivery to the CILAS pre-integration building, close to the PUPS and the LMJ building, to perform actual cleaning and integration of the opto-mechanical equipment. Complete systems are finally delivered to the proper LMJ laser hall where they are integrated within the amplifying sections.

Manufacturing of the 42 enclosures started in early 2013 with 6 units to be delivered per year.

The MegaJoule Laser (LMJ) is one of the most important tools used by the French Simulation program initiated by the CEA in 1996 to perpetuate the French nuclear deterrent following the decision to stop nuclear tests in the Pacific Ocean. The purpose of the program is to simulate nuclear fusion conditions using 176 laser beams which concentrate their power on a target a few millimetres in diameter. The LMJ is composed of 22 lines of 8 laser beams each.

Located at one end of the amplification section, the deformable mirror together with its associated control command system:

• Optimizes the laser beam alignment by tip and tilt of the mirror
• Corrects optical aberrations through mirror deformation generated by actuators

The control command system is made of racks (including power supply and controllers) integrated and cabled in a cabinet (one per laser line).

Based on a design of the complete system by CEA, ALSYMEX is responsible for the manufacture of the 22 deformable mirrors, including:

• Manufacture of the constituent mechanical parts
• Procurement of electronic components
• Clean room system assembly
• Integration of electronic rack and cabinet cabling
• Design and manufacture of a Man-Machine Interface (MMI) embedded in a test suitcase used to test, on site, operation of the global loop
• On-site integration and tests

The MegaJoule Laser (LMJ) is one of the most important tools used by the French Simulation program initiated by the CEA in 1996 to perpetuate the French nuclear deterrent following the decision to stop nuclear tests in the Pacific Ocean. The purpose of the program is to simulate nuclear fusion conditions using 176 laser beams which concentrate their power on a target a few millimetres in diameter. The LMJ is composed of 22 lines of 8 laser beams each.

In the amplification chain, xenon flash lamps are used to pump the laser by converting electric energy generated by capacitor banks into light.

Using its more than 20-year experience in the development of global high pulsed technology and manufacturing services, ITHPP was selected by the CEA to supply the High Coulombs Switches at the heart of the energy banks. The main specifications of such components are:

• Charge transfer: from 4 to 70 Coulombs
• Operating voltage: from 15 kV to 30 kV
• Current: from 25 kA to 250 kA
• Number of shots: up to 70 000 with no maintenance
• Mercury and SF6 free

ITHPP also develops and manufactures complete energy banks. The latest system, which has been supplied to the French National Scientific Research Center (CNRS) for high magnetic field experiments, has the following specifications:

• Stored Energy: 6MJ (2 × 3MJ)
• Operating voltage: from 1 to 24 kV
• Both positive and negative HV polarity
• Maximum operating current: 40 kA
• Short-circuit current in the range of 150 kA (2 × 75 kA),  limited by a protective inductor
• Transportable system

The MegaJoule Laser (LMJ) is one of the most important tools used by the French Simulation program initiated by the CEA in 1996 to perpetuate the French nuclear deterrent following the decision to stop nuclear tests in the Pacific Ocean. The purpose of the program is to simulate nuclear fusion conditions using 176 laser beams which concentrate their power on a target a few millimetres in diameter. The LMJ is composed of 22 lines of 8 laser beams each.

In 2010, ALSYMEX was selected for the design, manufacture, and integration of the 22 beam transport lines. The 176 laser beams originating in the amplification sections are transported at atmospheric pressure and over a length of 40 metres to the experimental chamber. Each beam is deflected by a set of 5 to 7 successive mirrors. In total, the 22 lines are composed of 263 mechanical structures and 984 motorized optical units. In addition, each line includes:

• An over-pressurized argon tube
• A rack for the diagnostic of the amplified laser beam Diagnostic with a reduction optical beam system (SORF)
• An automatic safe insertion system (SIOF)

All mechanical components are designed and manufactured to be compatible with ISO7 cleanliness standards. 

Due to the vicinity of the experimental chamber, they must also comply with nuclear regulations: materials with a low cobalt rate (stainless steel and aluminum alloy), electrical design ensuring EMC robustness, security & safety and ALARA approach.

Within the framework of the French MegaJoule Laser (LMJ) program, ALSYMEX was selected in 2003 to design, manufacture, assemble and install the laser amplification section at the CEA site (with the exception of the amplifier itself). This type of section, known as SAHA, comprises, for each of the 22 laser lines, a 105 metre-long, 100-tonne mechanical structure assembly containing opto-mechanical equipment controlling the propagation, shaping and optimization of laser beams. All inner volumes of the mechanical structure had to be designed to be compatible with ISO5 cleanliness requirements, some of them also needed to be vacuum sealed (10-4 Pa). Nuclear requirements also had to be considered due to the proximity of the experimental hall.

All together, about thirty different types of highly accurate large mechanical structures had to be designed.

A total quantity of 660 stainless steel structures were manufactured and delivered to the site for cleaning and assembly between 2006 and 2010, with an average annual production volume of 133 units.

Major characteristics of the mechanical structures 

• Outer dimensions: up to 10 m × 2.5 m × 2 m
• Weight up to 10 tonnes
• Accuracy 1/10° over a 10m length
• Cleanliness, ISO 5 to ISO 8
• Inner operating pressure: 10^-2 Pa (test conditions: 10^-4 Pa)

Cryogenic pumps have been developed to pump gases out of the ITER torus by adsorption on activated charcoal, cooled to a temperature of with around 4.5K. The cryogenic circuit of the coated surface is cooled by a forced flow of supercritical helium. Protection of coated surfaces against heat loads is achieved by surrounding them by a thermal shield, cooled by a forced flow of gaseous helium.

The cryogenic circuits are incorporated into a pump casing with an 800mm diameter inlet valve separating the pump from the torus, allowing for regeneration by heating the charcoal without interruption of plasma operation. The valve is controlled by an actuator. The position of the valve head enables throughput to the eight cryopumps operated by ITER to be throttled.

In partnership with RI-Research Instruments from Germany, ALSYMEX has been awarded a contract to manufacture the pre-production cryogenic pump by F4E.

ALSYMEX’s share of work includes:

• Manufacture and assembly of the Pump Plug and associated flanges, including dimensional and leak tests
• Manufacture of the Housing Sub-Assembly, including dimensional and leak tests
• Manufacture and testing of the valve shaft, head and stem assembly

The various sub-assemblies were manufactured and final assembly of the pump occurred in mid 2017. Qualification tests were performed at the Karlsruhe Institute of Technology at the end of 2017.

Main characteristics of the cryogenic pump

• Dimensions: 3.5 m long – 1.8 m diameter
• Weight: 8 tonnes
• Ultimate operating pressure: 10^-7 Pa
• Charcoal cooling: 0.4 MPa pressure, 4.3 K inlet temperature, 4.8 K outlet temperature
• Shield cooling: 1.8 MPa pressure, 80 K inlet temperature, 90 K outlet temperature
• Variable actuator stroke up to 470 mm

Given their dimensions (up to 25 m in diameter), the ITER poloidal coils must be fabricated on site. A dedicated facility (PF building) has been set up including all necessary tooling for winding, impregnation, handling, assembly and testing of the six superconducting magnets.

By the middle of 2015, the consortium comprising ELYTT (Spain), ALSYMEX has been awarded a contract for the design and manufacture of the impregnation tooling (under the responsibility of ELYTT) and seven additional tools for testing, handling and assembly.

ALSYMEX was tasked with the supply of a large vacuum vessel allowing for global leak testing of the incoming conductor spool in the PF building, particularly relating to potential damage during transport. The work included:

• Design and engineering studies
• Manufacture and factory tests
• On-site installation, commissioning and acceptance tests
• Proper certification
• Training of the external team in charge of operation of the facility
• Maintenance
• Associated documentation (procedures, specifications, operating manuals…)

In addition to the vessel, ancillary systems were also supplied, including:

• One vacuum pumping system
• One He pressurization circuit
• One unit for purging the conductor
• One leak sensor with leak calibration
• The system was successfully delivered to the ITER PF building in mid 2016.

Main characteristics of the vacuum vessel

• Stainless steel cylindrical shape with convex ends
• Outer dimensions: 6.3 m high, 5 m in diameter
• Weight: 20 tonnes (including pathways)
• Inner operating pressure: 10^-2 Pa

For over 20 years, IRELEC has been supplying the worldwide Synchrotron community with opto-mechanical systems operating under Ultra-High Vacuum conditions installed on soft and hard X-ray beamlines. IRELEC has developed know-how and expertise in the design, manufacture, assembly and commissioning of mechanisms and vacuum systems which are compliant with state-of-the-art vacuum technologies.

Main characteristics of the vacuum chambers

• Type: Bell-jar
• Dimensions: up to 2.2 metres long
• Ultimate pressure: 10^-10 mbar
• Leak rate < 10^-11 mbar.l/s
• Outgassing rate < 10^-12 mbar.l/s.cm²
• Sealing technology: aluminium wire seal on optical polished surface