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 3Sv/hr outside

General Layout of Shielding Structure

Inner layer of SteelOuter layer of Concrete

Shielding Costs

Latest UCN Layout

Vendor Quotes:Concrete $1251 kSteel (radioactive) $ 360 k (66%)Steel (new) $ 480 k (33%)Staging/Installation $ 20 kTotal $2111 k

Latest UCN Layout: Concrete $ 834 kSteel (radioactive) $ 240 k (66%)Steel (new) $ 320 k (33%)Staging/Installation $ 20 kTotal $1414 k

Original Cost Estimate (CFI prop):Concrete $ 900 kSteel (radioactive) $ 200 k (66%)Steel (new) $ 700 k (33%)Staging/Installation $ 20 kTotal $1820 k

Above estimates based on bulk volume estimates+20% contingency

More detailed layoutTRIUMF Design Office (A.Prorok)

Detailed Layout of UCN Shielding (1st Iteration)

Extent of existing Shielding Wall

UCN ConcreteShielding

UCN SteelShielding

UCN Shielding – Layer 1

Concrete shielding blocks – YellowSteel 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 ft3 ~50 m3

Shielding Costs from 1st 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

1st Iteration UCN Layout: Concrete $ 445 kSteel (radioactive) $ 485 k Steel (new) $ 240 k Staging/Installation $ 20 kTotal $1190 k

If above savings can be implemented, total cost for shielding $890 k

2nd 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 RCNP @ 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: 2A to 10A (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 D2O

20K D2O

Target

CoolingBlockCoolant LinesRails/Bearings Bellows

Rack & PinionSystem

Driveshaft(detachable)

Pb-Shielded Cask

Pb-ShieldedShutters

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 sealsTRIUMF 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

Accel.

& Engr Cntrls Elect Mech

1

2 30 2.5 3 5 4 2.5 2 193 04 05 06 100 1 10 4 3 4.5 13 35.57 08 09 0

10 130 3.5 13 9 7 0 4.5 15.5 2 54.511

12 2 9.5 4.5 1.5 7.5 11 3613 445 014 015 485 016 240 017 20 4 0.5 1 1 14 3 23.518 1190 6 10 5.5 1.5 0 1 21.5 14 59.519

1320.1 9.5 23 14.5 8.5 0 5.5 37 16 114Total

Preparation and InstallationSHIELDING TOTAL

(25 m3 new steel at 9.6k/m3)

Safety intelocksVacuum system

SPALLATION TARGET TOTALS

SHIELDINGConcrete shielding (160 m3 @ 2.78k/m3)

Steel shielding (160 m3)(135 m3 recycled steel @ 3.6k/m3 )

Remote handling, tranfer flask, target suspensionTargeting monitor and interlock

Water cooling (included in "Target")

Sub-projects/Work PackagesMat'l &

Supplies (K$)

Human Resource Requirements (Person Months)

Phys Design

Spallation Target & Shielding

Total

SPALLATION TARGETTarget (incl. jacket and support)

M/ShopTechnician

Outside

Costs & Human Resources Summary

More details in main Resources & Timeline Section

Possible reduction in Human Resources requirements: RCNP (Tgt), Acsion (Tgt, Shielding)

Shielding:

Final design mid-2012Procure shielding mid-2012 mid-2014Install Base layer mid-2013 Dec/2013Install remaining layers mid-2014 mid-2015

Target & RH system: Receive Target @ TRIUMF: Mar/2014Install Target @ 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 Layout NEW (“No PIF”) UCN Layout

Shielding Budgets

Original cost estimate (total) $1820 k (from CFI proposal)

Vendor Quotes:Concrete $1251 kSteel (radioactive) $ 360 k (66%)Steel (new) $ 480 k (33%)Staging/Installation $ 20 kTotal $2111 k

Latest UCN Layout: Concrete $ 834 kSteel (radioactive) $ 240 k (66%)Steel (new) $ 320 k (33%)Staging/Installation $ 20 kTotal $1414 k

UCN Shielding – Layer 2 (Base Layers)

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 ActivationLeaks Contamination Risks Low Contamination RisksBoiling 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 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.