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

UCN Shielding Requirements A.Trudel calculations (TRIUMF Safety Group) 40  A, 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 3  Sv/hr outside General Layout of Shielding Structure Inner layer of Steel Outer layer of Concrete

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

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

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

UCN Shielding – Layer 3

UCN Shielding – Layer 5

UCN Shielding – Layer 7

UCN Shielding – Layer 9

UCN Shielding Structure 4’ x 6’ x 18’ Concrete shielding blocks (on-hand, outside “Electronics” Trailer) Reuse existing concrete blocks from M11/M13  1836 ft 3 ~50 m 3

Shielding Costs from 1 st Iteration Layout 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  $300 k 1 st Iteration UCN Layout: Concrete$ 445 k Steel (radioactive)$ 485 k Steel (new)$ 240 k Staging/Installation$ 20 k Total$1190 k If above savings can be implemented, total cost for shielding  $890 k 2 nd Iteration Layout  Possible further improvements in “blocking” efficiency

Initial startup at 2  A (500 nA time-averaged)  Target cooling and residual activity  not a major issue  1  A  radiative cooling found to be adequate  residual activity  very low At higher currents 40  A (10  A 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: 2  A to 10  A (instantaneous)  Ideal opportunity to test system and resolve Cooling/RH issues Spallation Target & Remote-Handling System

Target Design 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 Model target after BNL target

Beam 300K D 2 O 20K D 2 O Target Cooling Block Coolant Lines Rails/Bearings Bellows Rack & Pinion System Driveshaft (detachable) Pb-Shielded Cask Pb-Shielded Shutters Flexible Shaft (remote-control cables) He 80 cm Remote-Handling System (Upstream Withdrawal) Pb-Shielded Cask and Target Mounting System

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

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

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

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

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

The End

Shielding Costs ORIGINAL (“With PIF”) UCN LayoutNEW (“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

UCN Shielding – Layer 2 (Base Layers)

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

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 A 2 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 A 2 transport limit.  The inventory of activity in the target at ten years is at approximately one fifth of the A 2 transport limit for Type A packages.