ITER Cryogenic System

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ITER Cryogenic System
ITER CODAC Colloquium 27th-28th October,
2008 Barcelona, SPAIN
Manel Sanmartí, CIEMAT-F4E Plants DIvision, ITER
Department
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Outline

• ITER cryogenic requirements
• ITER CRYO project frame
• ITER cryogenic system
• Cryo controls and instrumentation
• Conclusions

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Main duties

• Basic
• Cool-down of the cryostat and torus cryopumps
• Gradual cool-down and filling of the magnet
  system and the 80 K thermal shield in about one
  month
• Cool-down of the NB cryopumps, pellet units and
  gyrotrons
• Maintain magnets and cryopumps at nominal
  temperatures over a wide range of operating modes
  with pulsed heat loads due to nuclear heating and
  magnetic field variations
• Accommodate periodic regeneration of cryopumps
• Accommodate resistive transitions and fast
  discharges of the magnets and recover from them
  in few days
• Additional
• Ensure high flexibility and reliability
• Low maintenance

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Cryogenic capacity loads

• LHe cryoplant 65 kW equivalent _at_ 4.5 K
• Cooling of the superconducting magnet system
• 39 kW _at_ 4.2 K
• Cooling of HTS current leads
• 150 g/s GHe at 50 K
• Cooling of cryo-pumps with high regeneration
  frequency
• 6.5 kW _at_ 4.5 K and 70 g/s of LHe liquefaction
• Small users
• 1 kW _at_ 4.5 K (Gyrotron)
• LN2 cryoplant 1300 kW _at_ 80 K
• Thermal shielding
• up to 800 kW _at_ 80 K during chamber baking
• LHe cryoplant pre-cooling
• up to 280 kW _at_ 80 K during normal operation
• HTS 50 K extra cooling power
• up to 180 kW _at_ 80 K during normal operation

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Magnets Pulsed Head Load
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Operation scenarios

• Uninterrupted operation in order to maximize
  machine availability
• The tokamak will be operated during two 8-hour
  shifts
• The third shift will be used to recover nominal
  cryogenic conditions, for short interventions and
  to regenerate the cryopumps up to 470 K
• The large dynamic loads prevent full redundancy
  but allow continuous and uninterrupted operation
  without plasma
• Short maintenance periods of few days every two
  weeks
• Major shutdowns every 16 months
• RAMI analysis to improve the design and
  requirements for spares

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Technical variants

• Analysis of technical variants compatible with
  the requirements and basic design principles are
  presently under study
• Simplification of the layout and improvement of
  performances, reliability and availability or
  reduction of investment and operation costs
• Review and update of heat loads
• Large dynamic loads handling
• Pulse mitigation by temporary by-pass of the
  structure load
• Use of liquid helium storage buffering and
  complex process control
• Helium management and cold quench tank
  temperature level
• Optimal size, number of cold boxes and parallel
  operation (flow sharing)
• Thermodynamic cycle optimization for the
  refrigerators
• Developments of technology and engineering
  solutions for key components
• Example SHe circulating pumps and heat
  exchangers

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Outline

• ITER cryogenic requirements
• ITER CRYO project frame
• ITER cryogenic system
• Few thoughts on control and instrumentation
• Conclusions

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The ITER CRYO project frame

• Cryoplants system helium refrigerators, LN2 and
  80K loop system, ancillary equipment
  (warm/cold/liquid tanks, recovery purification
  systems)
• Cryodistribution system main distribution boxes
  with cold circulating pumps and cold compressors,
  cryolines from cryoplant building and inside
  tokamak complex
• Cryoplant procurement packages are based on
  functional specs and include manufacturing,
  delivery, installation on-site individual
  sub-package acceptance test

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Cryogenics Schedule
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Outline

• ITER cryogenic requirements
• ITER CRYO project frame
• ITER cryogenic system
• Few thoughts on control and instrumentation
• Conclusions

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ITER Cryoplant System
Cryodistribution
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Cryoplant architecture
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Cryoplant architecture
Pictures courtesy of CERN
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Cryoplant layout option 1
80 K He loop
Unloading area
LN2 plant
Instrumentation (control) room
Power supply
Room for power supply
Unloading area
Option 1 LN2 plant and boxes of 80 K helium
loop are located at outdoor area
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ITER Cryodistribution System
Cryodistribution
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Cryodistribution architecture
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ITER Cryodistribution system
gt50 Cold Boxes, 3 km of cryolines, 4500 components
Coming From cryoplant
CTCB
ACB STR
ACB PF
ACB TF
ACB CS
ACB Cryopumps
25000 LHe tank
Different levels
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Cryodistribution system PID
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ACB structure PID
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ACB Structure Detail Design
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Outline

• ITER cryogenic requirements
• ITER CRYO project frame
• ITER cryogenic system
• Controls and instrumentation for cryogenics
• As personal views this presentation does not
  necessarily reflect those from other involved
  parties (IO and IN DA)
• Conclusions

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Instrumentation requirements

• Cryogenic instrumentation (industrial
  process/plants)
• Pressure (1-200b, mbar, vacuum), Temperature
  (300-3.7K), Flow (warm/cold 2-2000 g/s),
• Gas quality impurities (N2/H20/CxHy-ppm)
• Actuators Control Pneumatic Valves, Quench
  valves (mech/PV), Heaters, Motors (On/Off, speed
  control)
• Switches (safety interlocks)
• Cryoplants
• Installed redundancy for inner instrumentation
  Cold Boxes
• Specific components like turbines (speed sensor,
  gas impurities)
• Cryoditribution
• Sub-atmospheric circuits (helium guard)
• Speed/Freq. controllers for circulators/cold
  comp.
• High magnetic fields and radiation environment
• Accessibility constrains (operation scenarios)
• Installed redundancy for inner instrumentation
  ACB

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Estimated I/O (tbc)
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Control requirements

• Cryoplants
• Modular individual control sub-systems
• Commissioning (staged, acceptance)
• Operation scenarios
• Dedicated PLC for critical components by
  suppliers turbines
• Cryoditribution
• High magnetic fields and radiation environment
• Accessibility constrains (operation scenarios)
• Dedicated PLC for critical components by
  suppliers cold circulators, cold comp.
• Master control system
• Cryo Integrated control system (IN, IO, EU)
• General/individual data/interlocks exchange with
  other WBS (magnets, TS, cryopumps)
• Machine interface (CODAC)
• Standardization hardware and software
• Flexibility and accessibility during
  commissioning and first years of operation
• Logging and post-mortem system for data/event
  analysis
• Quality control (software updates, modifications)

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Cryoplant control architecture?
OWS 1..x
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Cryoplant control architecture?
OWS 1..x
Data Servers
EWS 1..x
Ethernet
Storage
LHe CP1
LHe CP2
LHe CP3
Recup Purif.
80K Loop 12
LHe CB1
LHe CB2
LHe CB3
CTCB
LN2_1
LN2_2
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Cryodistribution architecture?
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Cryodistribution architecture?
EWS 1..x
OWS 1..x
Data Servers
Ethernet
Str. ACB
TF ACB
PF ACB
CS ACB
Cryopumps ACB
Accessibility constrains High magnetic field High
radiation enviroment
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Conclusions

• Cryogenics is a large industrial plant system
• Instrumentation and controls requirements are
  well understood and identified
• Controls architecture not yet defined
• RAMI analysis and other projects experience to be
  used
• Integration with clients (magnets, cryopumps, TS,
  others)
• Radiation and high magnetic fields impact on
  cryodistribution instrumentation and electronics
  has to be validated
• Standardization and integration of all cryogenics
  sub-systems is mandatory
• Hardware (IC) and software
• To be defined before PA by involved parties
• Common strategy and standard to be defined by all
  involved parties (IO, IN DA F4E) before PA

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THANK YOU!!
Manel.Sanmarti_at_f4e.europa.eu