1. Pipeline Explosion at Henderson, NV Pipe Crushing & Rupture Presented by: T. Kim Parnell, PhD, PE Parnell Engineering & Consulting (PEC) www.parnell-eng.com www.linkedin.com/in/parnellpec kim.parnell@stanfordalumni.org Reference: “Analysis of the Dynamic Response of a Buried Pipeline due to a Surface Explosion,” Computational Aspects of Impact and Penetration, L. E. Schwer and R. F. Kulak, eds., Elme Press International, 1991 (with R. D. Caligiuri).

2. kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 2 Introduction Overview of Incident Natural Gas Pipeline Details Finite Element Analysis of Pipe Crushing Summary Outline of Presentation

3. kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 3 T. Kim Parnell, PhD,PE - Biography T. Kim Parnell, Ph.D.,P.E. is Principal & Founder of Parnell Engineering & Consulting (PEC). Kim holds Ph.D. and MSME degrees in Mechanical Engineering from Stanford University, a BES from Georgia Tech, and is a registered Professional Mechanical Engineer in the State of California. Kim is a Senior Member of IEEE, a Fellow of ASME, and SAE Member. Kim was 2011 Chair of the IEEE Santa Clara Valley Section (IEEE-SCV) with over 12,000 members and Past-Chair of the IEEE Consultants' Network of Silicon Valley (IEEE-CNSV). Dr. Parnell served on the Mechanical Engineering faculty at Santa Clara University teaching materials, design, and manufacturing applications. He currently participates as a Lecturer in the Stanford Composites Design Program. He works extensively in Composite material issues including Damage, Delamination, and Failure. Dr. Parnell is active in areas such as alternative energy, finite element analysis, robust design, and the use of computer simulation to achieve better designs in shorter time. He frequently works in medical devices and is an expert in the areas of failure analysis and accident investigation, and uses this expertise to help develop more reliable product designs. He has extensive experience in the analysis and simulation of structures, heat transfer, and fluid flow using finite elements and other numerical procedures.. Dr. Parnell was recently at MSC.Software Corporation as Senior Manager in the Product Management group. He was the MSC Product Manager for Fatigue and Wind Energy. Before starting PEC, Kim was at Exponent Failure Analysis Associates (Senior Manager), Rubicor Medical (R&D Director), SST Systems, ATT Bell Laboratories, Stanford University and General Motors. He also was appointed as a Visiting Associate Professor in the Mechanical Engineering Department at Stanford University, teaching graduate courses in Mechanics.

4. 4 The PEPCON Incident Fire and massive explosions at the PEPCON plant in Henderson, NV on May 4, 1988. PEPCON produced Ammonium Perchlorate (AP) – an oxidizer Combination of events:  Large quantity of AP on site due to Challenger disaster  16” natural gas line running under the plant (with leaking stitch welds)

5. 5 PEPCON Explosions Two large explosions equivalent to 200 Tons and 500 Tons of TNT (3.0 and 3.5 on the Richter scale) Over $70M property damage; windows broken up to 30 miles away 16” Natural Gas Pipeline  Ruptured 40 foot section  Crushed more than 260 feet  Long-term leakage prior to blast from poor stitch welds

6. 6 Fire & Brimstone Rapid spread of fire; catastrophic explosion Most of event captured on video

7. 7 Massive Explosion & Shockwave Stills from video shot from Black Mountain – over 10 miles away See link to separate video of blast

8. 8 Aerial View - Before & After BeforeAfter

9. 9 16” Natural Gas Pipeline Ran near the plant property boundary Ruptured 40 foot section Crushed more than 260 feet Long-term leakage prior to blast from poor stitch welds Big Question: Did the pipe rupture occur before or after the explosions??

10. 10 Pipeline Section Identification

11. 11 Ruptured Gas Pipe – Initial View

12. 12 Pipe After Some Digging

13. 13 Pipe After Complete Excavation

14. 14 Gas Pipe Ruptured & Crushed Sections

15. 15 Pipe – Crushed Sections

16. 16 Plant Buildings

17. 17 Production Equipment

18. 18 Transient Finite Element Analysis of Pipe Crush due to Blast To Address the Big Questions:  Did the pipe rupture occur before or after the explosions??  Was the natural gas pipeline leaking and depressurized prior to the blast?

19. Pipe/Soil Model kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 19

20. Pipe Crushing Due to Blast Response Sequence #1 kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 20

21. Pipe Crushing Due to Blast Response Sequence #2 kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 21

22. Pipe Crushing Due to Blast Response Sequence #3 kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 22

23. Pipe Crushing Due to Blast Response Sequence #4 kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 23

24. Pipe Crushing Due to Blast Response Sequence #5 kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 24

25. Pipe Crushing Due to Blast Response Comparison Pressurized: P i =300psiUnpressurized: P i =0psi kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 25

26. Pepcon Site: Aerial View Pre-Incident kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 26

27. Pepcon Site: Aerial View Post-Incident kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 27

28. Pepcon Site after Incident kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 28

29. Pepcon Site after Incident kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 29

30. Pipeline-Unstable Crack Growth 16-inch underground natural gas line 300 psi internal pressure Poor quality welds (ERW pipe) Fast fracture of a 40-ft. section after initial weld defects grew through fatigue to critical size Resulting fire & explosions demolished the plant 30 kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec

31. Natural Gas Pipeline kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 31 16” Natural Gas Pipeline 40’ Ruptured Section Electric Resistance Weld (ERW) showed stitching and lack of fusion

32. Natural Gas Pipeline kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 32 16” Natural Gas Pipeline 40’ Ruptured Section Electric Resistance Weld (ERW) showed stitching and lack of fusion

33. Natural Gas Pipeline kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 33 16” Natural Gas Pipeline Crushed Section

34. Natural Gas Pipeline kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 34 16” Natural Gas Pipeline 260’ Crushed Section

35. Natural Gas Pipeline kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 35 16” Natural Gas Pipeline End 260’ Crushed Section

36. kim.parnell@stanfordalumni.org www.parnell-eng.com www.linkedin.com/in/parnellpec 36 16” Natural Gas Pipeline