1. Thomas Jefferson National Accelerator Facility Page 1 CEBAF Cryo & SRF Workshop April 3, 2014 Mathew Wright Cryogenic Systems Operations Engineer 1.1.4.6 Cryogenic Maintenance and Upgrade Plans Cryogenics CEBAF Cryogenics and SRF Workshop Jefferson Lab April 3, 2014

2. Thomas Jefferson National Accelerator Facility Page 2 CEBAF Cryo & SRF Workshop April 3, 2014 Outline 2014 Summer Maintenance Task List Examples Budget/Cost Estimates Schedule Helium Inventory Spares CHLI CHLII Future Maintenance Linac’s on one CHL @ 2K

3. Thomas Jefferson National Accelerator Facility Page 3 CEBAF Cryo & SRF Workshop April 3, 2014 Task List

4. Thomas Jefferson National Accelerator Facility Page 4 CEBAF Cryo & SRF Workshop April 3, 2014 Task List Task List (2014 Summer) Add a vaporizer to the CHLI main cold box (MCB) Clean HX1 in the CHLI MCB Replace and regenerate the carbon in the CHLI main carbon bed (the one outside). This job requires many months of clean-up Modify insulating vacuum piping for the CHLI MCB Install a super Conducting helium liquid level probe to CHLI MCB sub-cooler (HX9a) Repair oil leak on CHLI main compressor C4 Clean water side of all main compressor oil/water heat exchangers Remove the old purifiers (to make room for the new vaporizer) Install the LINAC low pressure relief system (hurricane reliefs) LN2 dewar fill station over pressurization prevention modifications

5. Thomas Jefferson National Accelerator Facility Page 5 CEBAF Cryo & SRF Workshop April 3, 2014 Add a vaporizer To prevent the temperature of the LN2 boiler becoming dangerously low during 2KCB Pump Downs damaging the LN2 boiler and shutting down CHLI cryo systems To shed capacity during off normal operations (CHLI @ 4K) It is a problem now because we are pumping one LINAC vs two LINAC’s

6. Thomas Jefferson National Accelerator Facility Page 6 CEBAF Cryo & SRF Workshop April 3, 2014 Clean HX1 in the CHLI MCB Reduce the amount of wasted LN2 Outlet temp of med pressure header cold causing carbon pipes to sweat and rust all the way to the compressor room and sometime get below the allowable temperature limit

7. Thomas Jefferson National Accelerator Facility Page 7 CEBAF Cryo & SRF Workshop April 3, 2014 Modify vacuum piping for the CHLI MCB Presently can only pump on the vacuum space through the diffusion pump Need extra vacuum port to be able to attach external pump like what is on CHLII CBX CHLI main CBX vacuum was leading cause of downtime at the end of 6GeV

8. Thomas Jefferson National Accelerator Facility Page 8 CEBAF Cryo & SRF Workshop April 3, 2014 Regenerate CHLI Carbon Bed This job requires many months of carbon drying process Life of carbon bed design ~8 year Installed 2004 Oil Carry over into CBX causes wasted LN2, rusty pipes, and if bad enough, will shut down the CBX

9. Thomas Jefferson National Accelerator Facility Page 9 CEBAF Cryo & SRF Workshop April 3, 2014 Remove the old purifiers

10. Thomas Jefferson National Accelerator Facility Page 10 CEBAF Cryo & SRF Workshop April 3, 2014 2014 Budget/Cost Estimates Material Cost Estimates based on Vendor Quotes

11. Thomas Jefferson National Accelerator Facility Page 11 CEBAF Cryo & SRF Workshop April 3, 2014 Schedule

12. Thomas Jefferson National Accelerator Facility Page 12 CEBAF Cryo & SRF Workshop April 3, 2014 Schedule

13. Thomas Jefferson National Accelerator Facility Page 13 CEBAF Cryo & SRF Workshop April 3, 2014 Schedule

14. Thomas Jefferson National Accelerator Facility Page 14 CEBAF Cryo & SRF Workshop April 3, 2014 Spares Typical Needed Compressor Body, Motor, Oil Pump, Oil Pump Motor Spare compressor bodies (6-9 month lead time after PO) Spare motors (9-12 month lead time after PO) Warm helium piping cross connects between CHLI and CHLII If a CHLII system compressor goes down If one down – 4K If two down – 300K Recommendation New C6 compressor skid Two spare compressor bodies (CHLII C1-C4) One 800HP motor (CHLII C1-C4)

15. Thomas Jefferson National Accelerator Facility Page 15 CEBAF Cryo & SRF Workshop April 3, 2014 Linac’s One CHL supporting LINAC’s @ 2K Add a large cryo valve on spare 9” bayonets Need to evaluate if we need to switch CHLI/CHLII with the South/North LINAC’s Unreliable and marginal heater/capacity problems Process modifications at CHL? Add 1.5kW external heater? Needs more process analysis

16. Thomas Jefferson National Accelerator Facility Page 16 CEBAF Cryo & SRF Workshop April 3, 2014 Future Maintenance CHLI future maintenance Leftover from List CHLII future maintenance Dewar Vacuum CBX Vacuum piping / system Warm Gas Tie-In New Compressor Skid (C6) LINAC Guard Vacuum Pumps Need Replacement