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UCN Beamline Shielding, Target & Remote-Handling UCN CDR (Sept/2010) L.Lee

UCN Beamline Shielding, Target & Remote-Handling UCN CDR (Sept/2010) L.Lee. UCN Shielding Requirements. General Layout of Shielding Structure Inner layer of Steel Outer layer of Concrete. A.Trudel calculations (TRIUMF Safety Group) 40 m A, 500 MeV protons stopping in W target

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UCN Beamline Shielding, Target & Remote-Handling UCN CDR (Sept/2010) L.Lee

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  1. UCN Beamline Shielding, Target & Remote-Handling UCN CDR (Sept/2010) L.Lee

  2. UCN Shielding Requirements General Layout of Shielding Structure Inner layer of Steel Outer layer of Concrete A.Trudel calculations (TRIUMF Safety Group) 40 mA, 500 MeV protons stopping in W target Assumes 0.5 m empty space around target (no moderator) Plot shows the shielding needed to reduce dose to 3mSv/hr outside

  3. Shielding Costs Original Cost Estimate (CFI prop): Concrete $ 900 k Steel (radioactive) $ 200 k (66%) Steel (new) $ 700 k (33%) Staging/Installation $ 20 k Total $1820 k Vendor Quotes: Concrete $1251 k Steel (radioactive) $ 360 k (66%) Steel (new) $ 480 k (33%) Staging/Installation $ 20 k Total $2111 k Latest UCN Layout Latest UCN Layout: Concrete $ 834 k Steel (radioactive) $ 240 k (66%) Steel (new) $ 320 k (33%) Staging/Installation $ 20 k Total $1414 k Above estimates based on bulk volume estimates+20% contingency More detailed layout TRIUMF Design Office (A.Prorok)

  4. UCN Concrete Shielding UCN Steel Shielding Extent of existing Shielding Wall Detailed Layout of UCN Shielding (1st Iteration)

  5. UCN Shielding – Layer 1 Concrete shielding blocks – Yellow Steel shielding blocks – Black/Silver

  6. UCN Shielding – Layer 3

  7. UCN Shielding – Layer 5

  8. UCN Shielding – Layer 7

  9. UCN Shielding – Layer 9

  10. UCN Shielding Structure 4’ x 6’ x 18’ Concrete shielding blocks (on-hand, outside “Electronics” Trailer) Reuse existing concrete blocks from M11/M13  1836 ft3 ~50 m3

  11. Shielding Costs from 1st Iteration Layout 1st Iteration UCN Layout: Concrete $ 445 k Steel (radioactive) $ 485 k Steel (new) $ 240 k Staging/Installation $ 20 k Total $1190 k Possible Cost Savings: • “Skyshine” dose limits are higher  remove uppermost 2 layers of shielding (?)  savings of ~ 22%  $225 k • Reuse existing steel from magnets  possible savings  $ 75 k Total savings  $300 k If above savings can be implemented, total cost for shielding  $890 k 2nd Iteration Layout  Possible further improvements in “blocking” efficiency

  12. Spallation Target & Remote-Handling System • Initial startup at 2 mA (500 nA time-averaged) • Target cooling and residual activity  not a major issue • RCNP @ 1 mA  radiative cooling found to be adequate • residual activity  very low • At higher currents 40 mA (10 mA time-averaged)  Require Target Cooling •  Water-cooling vs Helium-cooling • Model target after elements from existing designs at BNL, KEK, TRIUMF • Budget: $30k • Residual Activity & Remote-Handling • Retract target into a shielded cask • TRIUMF Remote-Handling specialists consulted  do-able at $100k • Target failure  Transfer to Horizontal transport flask (e.g. 2C-STF flask) and crane to existing Hot Cell facility • Prior to installation at TRIUMF (recent initiative with RCNP) • Spallation Target & RH system  use at RCNP • RCNP: 2mA to 10mA (instantaneous) • Ideal opportunity to test system and resolve Cooling/RH issues

  13. Target Design Model target after BNL target • BNL target • Pt target (segmented) coupled to Copper base • Water-cooled base • Heat load ~ 2kW (time-avg)  TRIUMF people involved in design of this target • UCN target  Tungsten alloy (HeavyMet) target; d~5 cm, L~11-14 cm • Coupled to water-cooled base (Cu?) • Heat load ~ 5kW (time-avg) • Water flow rate ~10 L/min to remove instantaneous heat load

  14. Flexible Shaft (remote-control cables) Driveshaft (detachable) Pb-Shielded Cask 20K D2O Rack & Pinion System He Pb-Shielded Shutters 80 cm 300K D2O Beam Target Cooling Block Coolant Lines Rails/Bearings Bellows Remote-Handling System (Upstream Withdrawal) Pb-Shielded Cask and Target Mounting System

  15. Water-Cooling Setup for 1AT1/T2 Target Ladder Bellows & Coaxial water lines on Target Ladder Custom seals TRIUMF M/Shop

  16. Target in Retracted Position  Retract Target into Cask • Access UCN cryostat OR Prep for Target Removal

  17. Target Removal/Disposal  Relocate Target + Cask to external (horizontal) transport Flask  Crane to Meson Hall Hot-Cell facility External Transport Flask (e.g. 2C-STF flask)

  18. Costs & Human Resources Summary • More details in main Resources & Timeline Section • Possible reduction in Human Resources requirements: RCNP (Tgt), Acsion (Tgt, Shielding)

  19. Schedule: Shielding and Target/RH Overview of Main Milestones (details in Resources & Timeline Section) Shielding: Final design mid-2012 Procure shielding mid-2012  mid-2014 Install Base layer mid-2013  Dec/2013 Install remaining layers mid-2014  mid-2015 Target & RH system: Receive Target @ TRIUMF: Mar/2014 Install Target @ TRIUMF: May/2014

  20. The End

  21. Shielding Costs ORIGINAL (“With PIF”) UCN Layout NEW (“No PIF”) UCN Layout Shielding Budgets Original cost estimate (total)  $1820 k (from CFI proposal) Vendor Quotes: Concrete $1251 k Steel (radioactive) $ 360 k (66%) Steel (new) $ 480 k (33%) Staging/Installation $ 20 k Total $2111 k Latest UCN Layout: Concrete $ 834 k Steel (radioactive) $ 240 k (66%) Steel (new) $ 320 k (33%) Staging/Installation $ 20 k Total $1414 k

  22. UCN Shielding – Layer 2 (Base Layers)

  23. Water-cooling vs Helium-cooling Water Cooling Helium Cooling Good cooling efficiency Low cooling efficiency  high flow velocities req. “Conventional” technology Greater Technical & Regulatory (ASME) complexity Activation of water Low Activation Leaks  Contamination Risks Low Contamination Risks Boiling of Coolant Two Water-cooled targets (1AT1 & 1AT2) in operation “near-by” Water-cooling infrastructure already available

  24. Spallation Target Calculations from Safety (A.Trudel) indicates target activity level after 10 years of irradiation will still be a factor of ~5 below the A2 transport limit • A stopping target of tungsten bombarded with 100 uA of 500 MeV protons. • Blue arrows correspond to 1, 5 & 10 years of irradiation. • Shown below the arrow is the total activity as a fraction of the A2 transport limit. • The inventory of activity in the target at ten years is at approximately one fifth of the A2 transport limit for Type A packages.

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