2. LANL Mission Is National
Security
• We develop and apply
science and technology to
– Ensure the safety and reliability
of United States nuclear
deterrent
– Reduce the threat of weapons
of mass destruction,
proliferation, and terrorism; and
– Solve national problems
regarding defense, energy,
environment, and infrastructure.
4. The Evolution
• Both NFPA 801 and DOE
Standard 1066, “Fire
Protection Design Criteria”,
require fire suppression to
be installed in gloveboxes
• During the design phase of
a multi-station waste
processing box we were
tasked to provide
recommendations for fire
suppression system.
5. Other Suppression Systems
• We looked at numerous fire suppression, or fire
mitigation systems.
– Water-based
• Inexpensive to procure and install
• Reliable
• Generate large volume of water that may
be difficult to dispose of
• Loss of containment
• Criticality issues
6. Other Suppression Systems
• Dry Chemical
– Expensive to procure and install
– Reliable
– Expansion of confinement boundary
• Inertion
– Expensive to procure and install
– Reliable
7. Seismic Reliability
• Water-based
– Water supply may be affected by a seismic
event
• Dry Chemical
– Storage cylinder and distribution piping may
be compromised seismic event
– Response time of the initiating device may
be adversely affected by a seismic event
• Inertion
– Inerting may be compromised or lost in by a
seismic event
8. Automatic Fire Extinguisher
• Our efforts led us to an automatic clean agent
fire extinguisher
– U.L. Listed (U.L. 2166) for Class B and C
fires
9. Envirogel Extinguishing Agent
• Contents of fire extinguisher:
– FE-25 & FE-36
– Sodium bicarbonate powder
– Charged with an inert gas to 100 psi
• Manufactures inquiries
– Extinguisher is currently utilized for Class A
applications
– Confident fire test would prove extinguisher’s
ability to successfully extinguish class A fires
– U.L. 2166 Class A fire test enclosure volume
~3500 cu.ft.
10. Automatic Fire Extinguisher
• Self contained and compact
• Activated by temperature
• Bolt-on simplicity
• No mechanical, electrical, or battery systems
required
• Rugged construction and maintenance free
• The extinguisher reacts to all fires
• Installation and orientation
• Volume protected
11. Automatic Fire Extinguisher
• Extinguisher is vibration and corrosion resistant
• UL approved for 130 cu.ft. enclosures and
NRTL Certified for 250 cu.ft. enclosures
• Airflow
• Automatic Extinguisher
– Extinguisher not affected by a seismic event
– Redundancy of extinguishers would yield an
extinguisher at the top of the glovebox
12. Operational Impact
• Cleanup is simple and
yield significantly less
waste than water
based fire suppression
systems
• Minimizes
environmental impact
• Return to service
15. Pressure Profile
Glovebox Pressure Profile - Test 6
4
Extinguisher tube activated at Time = 3:42 min
2
0
Pressure (in WC)
-2
-4
-6
-8
-10
-12
0 1 2 3 4 5 6 7 8 9
Time (min)
16. Temperature Profile
Glovebox Temperatures Profile − Test 6
600
500
Temperature (ºC)
400
300
200
100
0
0 1 2 3 4 5 6 7 8 9
Time (min)
TC 1 TC 3 TC 5
17. Test Protocol
• Lack of industry
standard fire test
• Test Protocol
– Structured for our
application
18. Collaboration with UT"
• Collaborated with the
Mechanical Engineering
Department of the
University of Texas at
Austin continues
• This effort is lead by
Professor Sheldon
Landsberger and Ofodike
A. Ezekoye
19. Experiments"
• Alpha experiments - Curium Source
– 10 microcuries on 3/1/98
– 18.11 year half-life
– 5 mm active area diameter
• Neutron experiments
– Irradiation 4+ months of glove samples
– Tensile testing
• More neutron experiments
– 5 Ci PuBe homogeneous neutron source
– Duration: 2 months
20. Fire Modeling
While LANL glovebox systems are designed and
operated with fire safety goals in mind,
suppression systems that meet strict reliability
requirements are integral parts of the overall fire
protection system for these systems.
Our project goal is to use calibrated and validated
fire and mechanical modeling tools to understand
the operating characteristics of the QuickFire Fire
Foe suppression system for gloveboxes.
http://www.quick-fire.com/products-01.asp
23. Development of Computational
Model
Schematic of small-scale FDS Gas temperature slice in
geometry setup small-scale FDS glovebox
24. Heat Release Rate Characterization
A fire of unknown size occurs…
The compartment is
instrumented with
thermocouples.
What HRR
Temperature
would cause
those
temperature
profiles?
Time
We use inversion.
25. Model Calibration to Experiment
Experimental
thermocouple
Gas temperature
temperatures compared
slice in small-scale
to FDS thermocouple
FDS glovebox
temperatures in the
small-scale experiment
26. Analytical Heat Transfer Model
• Fire Foe is modeled as a cylinder under
constant, uniform radiative heat flux.
• Forced convection with constant heat
transfer coefficient.
• Specific heat and density do not vary with
temperature.
27. CFD Prediction of Heat Flux
Time sequence of net heat flux of Fire Foe tube in
the small-scale case
28. Finite Element Analysis Tools
• SolidWorks Software – Finite element
analysis of Nylon 6-6 tube
• LibMesh – Open-source finite element
solver
29. Simulations
• Variables
– Size of glove box
– Intensity of fire
– Location of fire suppression system
– Location of vent hood
– Location of glass
• Results
– Is the Fire Foe system reliable for all cases?
– Optimal location for Fire Foe system
– Worst-case scenario
30. Testing Results Summary
• This result shows that even at a relatively low
internal temperature of approximately 150 °C,
the internal pressure and the relative loss of
strength of the PA66 will likely result in failure of
the tube.
• As more detailed modeling of the PA66 failure
process takes place, we will use data from
Kohan on the elongation (%) at break and at
yield for PA66. Kohan presents data at 23 °C
and 77 °C for tensile strength, tensile yield
strength, elongation at break, and elongation at
yield.
31. Collaboration with MSU"
• Collaborated with the
Mechanical Engineering
Department of the Montana
State University.
• This effort is lead by
Professor David A. Miller
32. Tensile Testing"
• Test Resources 1000R
tensile testing machine
was used to evaluate
mechanical properties.
• Maximum stress and
strain are reported from
industry standard tensile
test - ASTM 1708
33. Summary
• The extinguisher has been independently
certified to successfully extinguish Class A, B,
and C fires, based on LANL test criteria.
• The extinguisher presents the most reliable
means of suppression in a post seismic event
• Installation of the extinguisher will satisfy DOE
and NFPA requirements for automatic fire
suppression in gloveboxes.
• A computational fire model is being developed to
predict fire extinguisher activation time for a wide
range of fire inputs and glovebox configurations.
• Any questions?
34. Acknowledgements"
• The authors would like to acknowledge the
Department of Energy and LANL's Plutonium
Science & Manufacturing; Chemistry, Life, and
Earth Sciences; Engineering and Engineering
Sciences; and Nuclear & High Hazard Operations
Directorates, for support of this work.
