LBNF Far Site Timed Egress Prepared by Jim
LBNF (Far Site) Timed Egress Prepared by Jim Priest & Jim Niehoff Analysis & Fire Modeling conducted by Arup September 2019
Fire Protection/Detection Systems Detection: Air Sampling Smoke Detection Suppression: Automatic Pre-action type sprinkler system, Ordinary Hazard Smoke Exhaust Fan No. SEF-01 SEF-02 SEF-05 SEF-06 2 CFM Capacity Cryostat Cavern 30, 000 North South LBNF | Fire Safety Strategy 09/12/2019
LBNF Project – LBNF Fire/Smoke Study (Fire Scenarios) Central Utility Cavern North Cryostat Cavern South Cryostat Cavern 3 LBNF | Fire Safety Strategy 09/12/2019
Fire Modeling Scenarios (2016, 2018, & 2019) Fire Scenario 1 2 3 4 Location Cryostat Cavern, Below Mezz Cryostat Cavern, West Side Plume Type Fire Suppression Controlled Fire Size Peak HRR Balcony-Spill Yes 716 KW* Balcony-Spill No 10. 0 MW Balcony-Spill Yes 716 KW* Balcony-Spill Yes 3. 8 MW 5 Central Utility Cavern Balcony-Spill Yes 4. 1 MW 6 Cryostat Cavern West Side Balcony-Spill No 10. 0 MW 7 Central Utility Cavern Balcony-Spill No 10. 0 MW 8 Central Utility Cavern Balcony-Spill On 4. 1 MW Type of Fire Simulated 50% Wood, 50% polystyrene 50% Wood, 50% polystyrene Fan Status On On Off *The peak size of “ 50% Wood, 50% Polystyrene at 716 KW in Scenario 1 & 3 maybe light with sprinklers; since we know the foam reacts HRR may be higher, i. e. , 1 to 2 MW 4 LBNF | Fire Safety Strategy 09/12/2019
Overview and Simple Diagram of Ventilation at SURF PATH OF EXHAUST (SMOKE MANAGEMENT SYSTEM) 5 LBNF | Fire Safety Strategy 09/12/2019
ASET and RSET • Available Safe Egress Time (ASET) is the time interval between detection time and the onset of hazard. The term “maximum emptying time” (in min), being the time for clearing the occupants within the building/space. • Required Safe Egress Time (RSET) determined for that space for safe egress. It is the time taken for an individual or building/space population to reach safety, which can be understood as the target time for ensuring complete evacuation. • In other words, RSET must be less than the ASET 6 LBNF | Fire Safety Strategy 09/12/2019
Consideration for Egress • RSET considerations include: – Time from ignition to detection – Time from detection to the general evacuation warning to occupants – Evacuation time, which has two major phases: • Pre-movement time consists of the time required to recognize the emergency and then carry out a range of activities before travelling to exits • Travel time is the time required for occupants to travel to an assembly area 7 LBNF | Fire Safety Strategy 09/12/2019
The Issue • During the transition of construction and final assembly of the detector, exceeds the travel distances allowed by International Building Code (IBC). • In other words, the assembly of the detector does not allow the egress travel distance allowed by IBC. • To maintain clear air and visibility during assembly of detector since it exceeds building code travel distance. 8 LBNF | Fire Safety Strategy 09/12/2019
FRA and Arup agreed on Source: 2004 Stair Gradient 38. 8 35 9 Ascending Elderly Young Male Female Mean 0. 41 0. 46 0. 5 0. 47 0. 46 0. 53 0. 57 0. 56 0. 54 LBNF | Fire Safety Strategy Stair Gradient 38. 8 35 Descending Elderly Young Male Female Mean 0. 46 0. 48 0. 61 0. 57 0. 53 0. 6 0. 57 0. 62 0. 67 0. 615 09/12/2019
Descending & Ascending Example 10 LBNF | Fire Safety Strategy 09/12/2019
Assumptions • 144 occupants are assumed to be in the Cryostat Cavern. Out of 144 • occupants, 3 occupants are assumed to be located at each mezzanine (i. e. a • total of 6 occupants at the mezzanine level). 11 LBNF | Fire Safety Strategy 09/12/2019
Example of Various Analysis 12 LBNF | Fire Safety Strategy 09/12/2019
Example of Various Analysis 13 LBNF | Fire Safety Strategy 09/12/2019
Example of Various Analysis 14 LBNF | Fire Safety Strategy 09/12/2019
Summary of Results of Timed Egress Analysis ASET (>) RSET Request for Alternative Method (IBC) 2019 During Construction (Assembly) of Detector - In the event of a fire at 4950 L during construction, Cryostat Cavern occupants at 4950 L - Using a (During combination of the Assembly) mucking ramp and the fixed exit access open stair in the center of the Cryostat 15 mins 11. 75 mins Yes 2019 Central Utility During Construction (Assembly) of Cavern (During Detector Assembly) 15 mins 8 mins Yes 2016/2018 Cryostat Cavern Normal Operations, construction (Assembly complete – Considered worst case Complete) scenario with an Exit blocked 6. 3 mins No, meets travel egress distance per IBC Detector Completed Meets IBC Egress Travel Distance & ASET/RSET Assembly of Detector Meets Timed Egress Analysis ASET/RSET Year of Studies/Mode ling 15 2016/2018 Location Central Utility Cavern (Assembly Complete) LBNF | Fire Safety Strategy Conditions Normal Operations, construction complete – Considered worst case scenario with an Exit blocked 15 mins 09/12/2019
- Slides: 15