page 

 CONCLUSIONS 40 



ACKNOWLEDGMENT 40 



APPENDIXES 



A — Summary of NCEL Study Group Report on 

 Pressure Vessel Concepts and Implosion Effect 



B — Experimental Evaluation of Radial End-Closure 

 Seals 



41 



63 

 76 



C - Photoelastic Investigation of Stress Concentrations . . 

 REFERENCES 90 



