UITF ODH Discussion How to avoid ODH 2

UITF ODH Discussion How to avoid ODH 2 conditions? August 5, 2015 Thomas Jefferson National Accelerator Facility UITF Progress meeting Page 1

To refresh your memory… Today Labyrinth with “chicken wire” gate Thomas Jefferson National Accelerator Facility UITF Progress meeting Page 2

Thomas Jefferson National Accelerator Facility UITF Progress meeting Page 3

Cryo lines from CTF along wall GN 2 lines along the wall Thomas Jefferson National Accelerator Facility UITF Progress meeting SF 6 tank Page 4

Helium, Nitrogen and SF 6 Helium dewars: 1, 000 liters, 50 liters = 1, 550 L ¼ CM LHe capacity, ~ 400 L (? ) Total LHe supply from CTF…. Nitrogen line at 80 psi thru a 3/8 inch pipe = 22 cfm or 1, 320 cubic feet per hour SF 6 inside vessel that hold HV power supply: 25 ft 3 filled to 70 psi, ~ 54 lbs: total volume if released? 144 ft 3 Thomas Jefferson National Accelerator Facility UITF Progress meeting Page 5

Rough Dimensions Matt’s loose estimate, total volume: 22, 896 ft 3 Dick Owen made a more exact calculation: 25, 704 ft 3 Cave 2: 22’ x 54’ x 12’ ~ 14, 256 ft 3 exit/entrance Cave 1: 12’ x 60’ ~ 8, 640 ft 3 exit/entrance Exhaust vent to high bay Exhaust vent to outside Thomas Jefferson National Accelerator Facility UITF Progress meeting Page 6

Approved Labyrinth Fresh air pulled through “chicken wire” gate Thomas Jefferson National Accelerator Facility UITF Progress meeting Page 7

Improving the ventilation in Cave 2 Add a wall to help direct air flow Add ductwork leading to rear of Cave 2 Thomas Jefferson National Accelerator Facility UITF Progress meeting Page 8

Dick Owen performed a preliminary assessment…he considered LHe dewars, GN 2 and SF 6. Thomas Jefferson National Accelerator Facility UITF Progress meeting Page 9

¼ CM cold by January 2016 HDIce moved into place starting May 2016 SSG building an ODH system, I assume they have planned for enough heads and in the right locations How to avoid ODH 2? What accidents are we required to plan for? Can the old ODH assessment be updated to account for additional volume and extra 1550 L of additional LHe? Save a bit of time and labor? Ventilation concerns: ODH related, replenishment of air non-ODH related, comfort? Is it clear what problems we are trying to fix? Thomas Jefferson National Accelerator Facility UITF Progress meeting Page 10

Concrete demolition complete • Stairs are next (complete in FY 15) • Bi-weekly meetings scheduled Thomas Jefferson National Accelerator Facility UITF Progress meeting Page 11

Cryo lines compatible with old and new ¼ CM… Looks similar to our “upgrade injector” front end Thomas Jefferson National Accelerator Facility UITF Progress meeting Page 12