1. The Cryopit Fraser Duncan Cryopit Workshop 16 August 2011

2. Underground Campus Personnel facilities SNO Cavern Ladder Labs Cube Hall Cryopit South Drift HALO Stub J-Drift Utility Area Fraser DuncanCryopit Workshop 16 Aug 2011

3. Cryopit Fraser Duncan

4. SNOLAB, an expansion of the original SNO laboratory, was proposed by the original SNO Canadian universities (Carleton, Guelph, Laurentian, Queen's and UBC) and University of Montreal with Carleton University as the Lead institution. The project was divided into Phase I (Cube Hall, Ladder Labs, new lab entrance) and Phase II (the Cryopit) to provide a break point to control project cost. The Cryopit, at $16M, was an addition to the initial SNOLAB grant and was funded 50% from federal and 50% from provincial contributions. It was conceived as a hall that could readily be isolated from the rest of the underground facility in the case that it contained a large inventory of cryogens or other substances that could displace significant volumes of air. Excavation began in 2007 and was completed in 2008. Was brought to a clean room state in March 2011. Third largest cavity after the SNO Cavern and Cube Hall (about 1/3 the size of the SNO Cavern). Cryopit Workshop 16 Aug 2011 History Fraser Duncan

5. Cryopit Workshop 16 Aug 2011Fraser Duncan BAR (Bottom Access Drift) Cryopit Bottom Access Ramp Airlock STAC (Staging Area Cryopit) Cube Hall TAC (Top Access Cryopit) J-Drift Notches for Pressure Bulkheads

6. Cryopit Workshop 16 Aug 2011Fraser Duncan Limited “As Built” Surveys have been Done

7. The Cryopit

8. Cryopit

9. STAC (Staging Area Cryopit)

11. Cryopit Utility Drift (J-2 Drift)

12. TAC (Top Access Cryopit)

13. Bottom Access Drift

14. Bottom Access Ramp Airlock

15. The Cyropit is designed to be operated at a higher air pressure than the surrounding areas to force dust out. The air is recirculated through HEPA filters. Particulate measurements are done on a regular basis. With no work being done in the Cryopit, achieving much better than the class 2000 goal. Cryopit Workshop 16 Aug 2011 Cleanliness Fraser Duncan

16. Present:  Ventilation: Nominally 5 air changes/hr through HEPA filtered, cooled air.  Fire Water and Chilled Water (also available for process equipment). Future:  Power: Design is for a 400 A service at 600 V phase with a Motor Control Centre located south of the Cryopit.  Communications: Tie in to existing fibre network.  Fire Detection: Detection and alarming contract issued and should be complete by year end.  Plumbing: Industrial Water, Ultra Pure Water, Forced Drain, Compressed Air. Cryopit Workshop 16 Aug 2011 Services Fraser Duncan

17. Safe venting in the case of cryogenic boil off or other release of inert gas. 1200 ft (370m) run from Cryopit to sealed exhaust raise. Possibly install pressure bulkheads around the cryopit. Need to coordinate with other experiments also planning to use vent raise. MC Collab Mtg Yale 19-21 July 2011 Exhaust Venting Fraser Duncan

18. Cryopit Workshop 16 Aug 2011Fraser Duncan Cryopit Configuration Options

19. Cryopit Workshop 16 Aug 2011Fraser Duncan Option: Stand Alone Tank

20. Cryopit Workshop 16 Aug 2011Fraser Duncan Option: Spray on Liner

21. Cryopit Workshop 16 Aug 2011Fraser Duncan Option: Small Tank and Deck

22. The Cryopit has been a 3,900 m 3 class 2000 clean room since May 2011. Beneficial occupancy could occur Jan 2011 with completion of fire detection. Electrical infrastructure would also need to be installed. Could deploy a short term experiment almost immediately by constructing a small tank and deck. Fully exploiting the cavity would (likely) require design and installation of large deck and liner/tank. Cryopit Workshop 16 Aug 2011 Summary Fraser Duncan

23. End