Update on Chemical Reactivity Measurements with Graphite and CFC

1
Update on Chemical Reactivity Measurements with
Graphite and CFC

• T.D. Marshall, R.J. Pawelko, G.R. Smolik,
• T.W. Walters, J.P. Sharpe

INEEL Fusion Safety Program
2
Current Status of Chemical Reactivity Tests with
CFCs

• INEEL performed steam reactivity tests with two
  European (Société Européenne de Propulsion) CFCs
• NB31 3D CFC, ? 1.91 g/cm3
• BET Specific Surface Area (avg) 2094 cm2
• H2 reaction rate (800 C) 8 x 10-7 l/cm2-hr
• C reaction rate (800 C) 9 x 10-5 g/cm2hr
• NS31 3D CFC, ? 2.09 g/cm3, 10-12 at.Si
• BET Specific Surface Area (avg) 2218 cm2
• H2 reaction rate (800 C) 5 x 10-8 l/cm2-hr
• C reaction rate (900 C) 9 x 10-4 g/cm2hr

3
Current Status of Chemical Reactivity Tests with
CFCs (cont)

• The Max-Planck performed air reactivity tests
  with two of the European (Société Européenne de
  Propulsion) CFCs
• NB31 3D CFC, ? 1.91 g/cm3
• C reaction rate (800 C) 6 x 10-3 g/cm2hr
• NS31 3D CFC, ? 2.09 g/cm3, 10-12 at.Si
• C reaction rate (900 C) 3. x 10-4 g/cm2hr
• Tests performed without gas analysis and at
  atmospheric conditions (i.e., no forced air flow)

4
Future INEEL Chemical Reactivity Tests

• Air reactivity tests with the European NB31 CFC
  should start in November 2001
• Measurements from these tests include
• CO and CO2 generation rates
• C reaction rates
• Experimental Parameters
• 100 sccm air (and Ar-O) flow over CFC during
  heating
• CFC temperature 500 - 1000 C
• heating times of 1 - 24 hrs
• Examine influence of fiber direction on C
  reaction rate
• Explore phenomenon of C self-heating at elevated
  temperatures

5
New Analyses to be Performed Using Updated
Graphite/Air Oxidation Rates
note 1) publication pending for the German
data 2) graphites used Poco, UC, and CFC

• New data shows graphite is much less reactive
  Why???
• Complimentary measurements to be made at INEEL