Peaceful Uses for Nuclear Explosions

The examples below are all from serious to semiserious sources - that is, sources where at least some thought was put into them beyond "what would make a cool picture".

Emphasized items were applications that were actually done at least once.   For the record, many of the weirder ones in here don't seem to have been taken very seriously even by their originators, and were more napkin exercises than serious proposals - I'm thinking particularly of #30, #33, and #39.

I am confident this list is not complete, and I will update it if I discover any new ones.   If you know of any I'm missing, please let me know in the comments.


Update 7/1/13: Added #42: Asteroid Deflection.

Update 8/10/13: Added #43: Signal Flare.

1. Creating harbors
2. Creating mountain passes
3. Excavating canals
4. Excavating reservoirs
5. Creating dams
6. Removing navigation hazards in waterways
7. Excavation of a mountainside for "recreational purposes"
8. Removing dangerously unstable rock formations after landslides
9. Excavating a fixed-dish radio telescope
10. Freeing oil from oil shale or oil sand
11. Breaking up rock to stimulate natural gas and oil production
12. Breaking up rock for mining or producing construction aggregate
13. Breaking up rock to extract copper or other minerals through in situ leaching
14. Breaking up rock to alter hydrological cycles
15. Developing geothermal energy sources
16. Preventing coal gas explosions
17. Creating useful radioisotopes
18. Generating electricity
19. Generating heat and pressure for chemical reactions, such as gassifying coal
20. Excavating underground storage tanks for gas or fuel oil
21. Disposing of sewage or industrial or nuclear waste
22. Generating ground shock for seismic sounding
23. Generating neutrons for physics experiments, e.g. creating new elements through neutron capture
24. Tracking the movement of large air masses through radioactive tracers
25. Experiments in high-pressure, high-temperature physics and chemistry
26. Determining density of the interplanetary medium through X-ray fluorescence
27. Determining structure of the moon through blast throw-off and X-ray fluorescence
28. Providing temporary communications relays by creating an artificial zone of high-density ions in the upper atmosphere
29. Extracting water from lunar regolith
30. Weather modification
31. Modifying the terrain to reduce the effects of pollution
32. Spacecraft propulsion
33. Aircraft propulsion
34. Breaking up ice in ice-locked harbors and channels
35. Melting glaciers
36. Desalination
37. Extinguishing gas and oil well fires and closing uncontrolled oil leaks
38. Destroying chemical weapons stockpiles
39. Relieving stress on fault lines to prevent earthquakes
40. RADAR imaging of other planets' surfaces
41. Manufacturing diamonds
42. Asteroid deflection
43. Detonating at high altitude as a signal flare