1. A WAY TO CHARACTERIZE THE RANGE OF VALIDITY OF A FIRE MODEL Kevin McGrattan National Institute of Standards and Technology Gaithersburg, Maryland, USA Taylor Myers University of Maryland College Park, Maryland, USA

2. US NRC/EPRI Fire Model Validation Study NUREG-1824

6. Big fires in a small space… Small fires in a big space… 2.2 m 22 m Credit USN and Bob Vettori (NIST)

7. W L D H LfLf r cj

8. Fire Froude Number W L D H LfLf r cj

9. Flame Height relative to Ceiling Height L f /H W L D H LfLf r cj

10. W L D H LfLf Relative Distance along the Ceiling, r cj /H

11. W L D H LfLf r cj Target distance relative to Fire Diameter r rad /D r rad

12. W L D H LfLf r cj Global Equivalence Ratio

13. Characteristic Fire Diameter Relative to Cell Size D*/dx W L D* H LfLf r cj

15. Acknowledgments: Dave Stroup, Mark Salley – US Nuclear Regulatory Commission Francisco Joglar – SAIC/EPRI References NUREG-1824, V&V of Selected Fire Models for Nuclear Power Plant Applications NUREG-1934, Nuclear Power Plant Fire Modeling Application Guide