DOT HS 811 075 February 2009

Failure Modes and Effects Analysis for Hydrogen FuelCell Vehicles Subtask 1

Final Report

This document is available to the public from the National Technical Information Service, Springfield, Virginia 22161

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This publication is distributed by the U.S. Department of Transportation, National Highway Traffic Safety Administration, in the interest of information exchange. The opinions, findings, and conclusions expressed in this publication are those of the authors and not necessarily those of the Department of Transportation or the National Highway Traffic Safety Administration. The United States Government assumes no liability for its contents or use thereof. If trade names, manufacturers names, or specific products are mentioned, it is because they are considered essential to the object of the publication and should not be construed as an endorsement. The United States Government does not endorse products or manufacturers.

TECHNICAL REPORT DOCUMENTATION PAGE

1. Report No.

DOT HS 811 075 2. Government Accession No. 3. Recipient's Catalog No.

4. Title and Subtitle Failure Modes and Effects Analysis for Hydrogen Fuel Cell Vehicles Subtask 1

5. Report Date February 2009

6. Performing Organization Code

7. Author(s) Denny R. Stephens, Susan E. Rose, Stephanie A. Flamberg, Stephen M. Ricci, and Paul E. George II

8. Performing Organization Report No.

9. Performing Organization Name and Address Battelle Memorial Institute 505 King Ave Columbus, OH 43201

10. Work Unit No. (TRAIS)

11. Contract or Grant No. DTNH22-02-D-02104

12. Sponsoring Agency Name and Address National Highway Traffic Safety Administration 1200 New Jersey Avenue SE. Washington, DC 20590

13. Type of Report and Period Covered Final

14. Sponsoring Agency Code Office of Applied Vehicle Safety Research Structures and Restraints Research Division, NVS-321

15. Supplementary Notes

16. Abstract

Hydrogen fuel cell vehicles (HFCVs) offer the promise of significantly reducing the amount of pollutants expelled into the environment. However, the technology that is needed to store the hydrogen fuel onboard and deliver it to the propulsion system is different from what consumers and even engineers currently know and understand. As an early step in identifying critical safety requirements for these vehicles and, if needed, developing appropriate Federal Motor Vehicle Safety Standards, the National Highway Traffic Safety Administration requested that Battelle undertake a high-level failure modes and effects analysis to characterize potential hazards from compressed-hydrogen fuel cell vehicles and identify potential safety issues. The objective of this effort is to review and assesses safety issues for hydrogen vehicles and to identify areas that NHTSA may consider addressing in the FMVSS.

The investigation found that, overall, the failure modes that appear to have the greatest hazard in hydrogen vehicles are large releases of hydrogen and rupture of the fuel container. The FMEA results show that if high-pressure components in compressed-hydrogen fuel systems lack redundancy, a single-point failure of the container, PRD, or first valve, can result in a large-scale release or venting of hydrogen and, for containers, release of mechanical energy. Small releases of hydrogen and rupture of other components may also be hazardous, but do not have the potential destructive force of large releases and fuel container rupture.

17. Key Words hydrogen, fuel cell, compressed hydrogen, fuel storage, FMEA, HFCV, risk, hazard

18. Distribution Statement This report is free of charge from the NHTSA Web site at www.nhtsa.dot.gov

19. Security Classif. (of this report) Unclassified

20. Security Classif. (of this page) Unclassified

21. No. of Pages 170

22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

Failure Modes and Effects Analysis February 2009 for Hydrogen Fuel Cell Vehicles i Final Report

http://www.nhtsa.dot.gov/

Failure Modes and Effects Analysis February 2009 for Hydrogen Fuel Cell Vehicles ii Final Report

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Executive Summary...................................................................................................................... v

Acronyms and Abbreviations .................................................................................................... vii

1.0 Introduction....................................................................................................................... 1

1.1 Project Objectives ................................................................................................... 1

1.2 Technical Approach ................................................................................................ 2

2.0 NHTSA and FMVSS Background................................................................................... 4

3.0 Elements of Compressed-Hydrogen Fuel Cell Vehicles ................................................ 6

3.1 Hydrogen Fueling and Fuel Storage Subsystem..................................................... 8

3.2 Hydrogen Fuel Delivery Subsystem ....................................................................... 9

3.3 Fuel Cell Subsystem ............................................................................................... 9

3.4 Electric Propulsion and Power Management Subsystem...................................... 10

4.0 Unique Hazards of Compressed-Hydrogen Vehicles .................................................. 11

4.1 Combustion Hazards............................................................................................. 11

4.2 High-Pressure Hazards.......................................................................................... 14

4.3 Electrical Hazards ................................................................................................. 16

4.4 Crash Hazard......................................................................................................... 18

4.5 Fire Hazards .......................................................................................................... 20

5.0 Failure Modes and Effects Analysis of Compressed-Hydrogen Fuel Cell

Vehicle.............................................................................................................................. 21

5.1 Description of the FMEA Development Process.................................................. 21

5.2 Description of the Results..................................................................................... 24

6.0 Comparison of FMEA Results With Fuel Cell Vehicle Codes and Standards.......... 52

6.1 Review of Codes and Standards ........................................................................... 52

6.2 Review of FMEA and Related Codes and Standards ........................................... 53

6.3 Potential Gaps in Standards .................................................................................. 72

7.0 Resulting Assessment of Safety Issues........................................................................... 75

7.1 High-Consequence Failure Modes........................................................................ 76

7.2 Root Causes and Design Controls......................................................................... 77

7.3 Highly Variable Hazards....................................................................................... 78

8.0 References ........................................................................................................................ 81

Appendix A: Summary of Hydrogen Vehicle Codes and Standards .................................. A-1

SAE Recommended Practices......................................................................................... A-1

ISO Safety Specifications ............................................................................................... A-8

CSA Draft Standards..................................................................................................... A-13

Japanese HFCV Standard ............................................................................................. A-16

European Working Group............................................................................................. A-19

Appendix B: Failure Modes and Effects Analysis of Compressed-Hydrogen Fuel

Cell Vehicles With Codes and Standards ................................................................... B-1

TABLE OF CONTENTS

Failure Modes and Effects Analysis February 2009 for Hydrogen Fuel Cell Vehicles iii Final Report

Page

List of Tables Table 1. Organization of FMVSS Standards ............................................................................................. 5

Table 2. Comparative Transportation Fuel Properties............................................................................. 12

Table 3. HFCV Concept Model Systems, Subsystems, and Components............................................... 22

Table 4. Likelihood Categories ............................................................................................................... 24

Table 5. Consequence Categories............................................................................................................ 24

Table 6. FMEA of Compressed-Hydrogen Fuel Cell Vehicle........