Status of Soudan: After the Fire Dan Bauer, All Experimenter’s Meeting, April 4, 2011

1. Status of Soudan: After the FireDan Bauer, All Experimenter’s Meeting, April 4, 2011

2. Administrative structure of Soudan • Minnesota Department of Natural Resources (DNR) • Owns and controls the mine, hoist and surface facilities • University of Minnesota • Leases underground caverns and manages the Soudan Underground Laboratory • Operates small experiments • Fermilab • Operates two experiments: MINOS and CDMS • Participates in safety reviews

3. Timeline of the Soudan Fire • The Fire Begins • 9pm, March 17 • Mine crew notified by EMS autodialer of fire alarm, which drops power to the underground laboratory and MINOS • UPS units on CDMS signal power outage via email • CDMS diesel generator starts but does not continue to run • 10pm, March 17 • Mine crew and DNR onsite; large plume of smoke from headframe of the mine is visible • They begin viewing the underground cameras at level 27 and in the lab. No smoke seen at that time; fire doors still closed. • Manually shut down key elements of CDMS remotely

4. Timeline of the Soudan Fire • First Response • Morning, March 18 • First access made with biopacks (DNR and UMN staff) down to level 22 to try to direct water toward the fire. • Power feed down the shaft shorted. Team sent down to level 27 to try to decouple power feed from lab to allow water pumps top run at higher levels. • Significant smoke and burning embers seen at level 27 but no report of visible flame

5. Timeline of the Soudan Fire • Fighting the Fire • Day and Evening, March 18 • Minnesota Interagency Fire Command sends team • Incident Command Center established • Install a cover on the top of the shaft to limit air flow and deprive fire of oxygen • Pump 50,000 gallons of water mixed with fire-fighting foam down the shaft

6. Smoke and Foam

7. Timeline of the Soudan Fire • Making Sure Fire is Out and Checking Shaft • March 19 • Run hoist down; CO levels still elevated but foam everywhere. • Pump another 20,000 gallons of water mixed with fire-fighting foam down the shaft • March 20 • Power restored to water pumps on Level 12, 22 • People sent down to evaluate shaft damage; judged to be safe for crews to reach level 27.

8. Damage in the Shaft

9. Timeline of the Soudan Fire • Progress and Setbacks • March 21 • Two trips to level 27 to try to assess power feed; one leg shorted and the other has 1MOhm to ground • Foam filled drifts; needed to be sprayed down to get to electrical equipment. • March 22 • Success in using working leg of power feed to get sump pumps going • First access to underground lab; foam pushed open the doors to the MINOS cavern and reached the detector.

10. Foam in the Underground Lab

11. Timeline of the Soudan Fire • Clearing the shaft and repairing the hoist • March 23 -> 27 • DNR did a lot of debris removal, shoring up loose material, straightening of the hoist rail and preparation to allow safe underground access for lab staff. • Incident command wraps up work and moves out • Onsite crews take a well-deserved weekend break

12. Timeline of the Soudan Fire • Assess and Stabilize the Experiments • March 28-31 (Dan Bauer, Alec Habig, mine crew staff) • Limited power restored to Soudan cavern and CDMS • CDMS experiment survived 11 days w/o power; warmed from 50 mK to room temperature. Tests reveal no damage to the cryogenics system. Pumped out thoroughly, then backfilled with dry nitrogen. • Purge reestablished to low background experiments • MINOS electronics did not get foamed, but magnet coil and UPS are soaked. • CDMS Diesel Generator is also soaked and may not be operational. • Debris swept up, but LOTS of cleanup left to do.

13. Current Status of Underground Lab • Network is up and running but some optical fibers damaged in the shaft • Fire Panel is operational and remotely accessible • Sprinkler system leaks and needs significant plumbing repairs at level 27 • VoIP phones and pager communications working • Video monitoring restored • Temporary fresh air now moving being funneled into Lab but air handlers are off • Power usage is minimal to avoid overloading damaged power feed (MINOS cavern still off)

14. Shaft Work • Clear debris and repair landings • Significant reconstruction of bottom 300’ needed before any new utilities can be mounted • Repair damage to hoist stop rails • Remove damaged pipes and cables • Install new power feed and communications • Establish independent power feed and backup power for water pumps. • Best estimate is that this will take 2-3 months

15. Lab Recovery Plan • Next goal is to get more power into lab to minimize further damage. Need HVAC and heat to reduce humidity and possible moisture damage. • Safe Access to the shaft is still several weeks away to install permanent full-capacity power feed. • Temporary solution is to run smaller feed just for lab that would allow for about half of normal capacity. Not enough to run experiments, but sufficient to get the lab back in shape. • Also need to repair the sprinkler system and clean up the foam residue. • This is probably a few weeks of work

16. Timeline for Recovery • Week of April 4th • Swap fiber connections to get better communication and network • Continue to help DNR stabilize the shaft and cleanup man-way landings • Get Sprinkler contractor underground to plan for repair of sprinklersystem • Do west shaft inspection so we can start minimizing cage trips • Week of April 11th • Continue shaft repairs and cleanup in underground Soudan cavern • Earliest opportunity to install temporary 2400V power feed • Week of April 18th • If temporary power feed in place, restore power to underground HVAC and MINOS cavern lighting • Begin first pass cleanup in the MINOS Hall. • Get sprinkler systems back in operation. • Continue shaft cleanup and stabilization. • Week of April 25th • Joint DNR/U of M After Action review of incident scheduled in Duluth for April 27th. • Continue lab cleanup and shaft repair. • Week of May 2nd • IF all of the above gets done schedule the first visit by U of M code officials and Fermilab ES&H to begin process of obtaining at least a partial certificate of occupancy. This is required before allowing noncertified cage riders, including most experimenters, underground.

17. Cleanup Work

18. MINOS Cleanup

19. CDMS and MINOS Plans • CDMS • Wait until lab power and HVAC stable to open experiment and remove detectors • Prepare for the summer science run with full detector payload (as originally planned) • Replace the diesel generator and get electrical work done to allow backup of electronics on new generator • MINOS • Dry and checkout electronics • Dry out the magnet coil; repair/replace the UPS

20. Cause of the Fire Initial Report from the State Fire Marshall This fire occurred in the mine shaft at about the 25th level and was most probably caused by sparks produced by maintenance work in the shaft. Fire damage was confined to the shaft near the 25th level. There was no apparent fire damage on the 27th level and no apparent fire damage to the research lab. This fire is considered accidental at this time.