We already have them. The technology to do this is very old.
Do you think that Lockheed has an excel spreadsheet or a CAD template laying around that, only after punching in a few parameters will kick out a design? Do you think that they will do this without modeling it? Do you know how many years it takes just to design the model? And how long it takes just to get the data to feed, design and test the model?
We already have them in the stockpile.
The US nuclear stockpile is still over 5000 very sophisticated weapons already "tuned" to do everything except produce high amounts of neutron radiation (Carter blocked the 'neutron bomb'). The peak us stockpile was over 30,000 nuclear and thermonuclear weapons - every kind of design imaginable has already been developed and exists.
We are talking about a thermo-nuclear device.
No we are not.
Thermonuclear devices use nuclear fusion. We are talking about a much smaller fissionable device.
Who has access to these things?
The US Military.
Even after many weapons were dismantled - certain W80 weapons would have been suitable - some of the best for this task have been dismantled - there are still plenty of nukes on the shelf.
Do you think that we have stockpiles of these devices laying around that are designed to withstand the huge amount of pressure of ocean water, then jammed down a pipe for over mile, and somehow still detonate?
Of course we do! Our nuclear inventory
The pressure is irrelevant. A BOP was delivered to that depth and was able to mostly function... or not.
A nuclear bomb is a very simple device and a VERY heavy one that is not harmed by pressures. It is not a firecracker that will become waterlogged and not light. W80 Did the Soviets, in those Propaganda films have that sort of thing?
Yes. They stopped bad spills with nukes, hence this discussion.
Where in the world would you find, assemble, direct and manage a team that could come up with the perfect solution, construct a device that uses technology made to rapidly destroy cities, in a marine environment that even BP or the government doesn't even understands.
There is no perfect solution. This thread assumes that this well will spew oil until it is dry, so more holes would not necessarily worsen it - if it is all going to leak out anyway.
Dial-a-Yield capability of modern nuclear weapons
The W80 is physically quite small, the "physics package" itself is about the size of a conventional Mk.81 250 lb (113 kg) bomb, 11.8 inches (30 cm) in diameter and 31.4 inches (80 cm) long, and only slightly heavier at about 290 lb (132 kg).
YES, Armorers have the ability to select the yield of the resulting explosion in-flight, a capability sometimes referred to as "dial-a-yield" but more properly variable yield. At one end of the scale, perhaps using just the boosted fission primary, the W80 has destructive power equivalent to around 5 kilotons of TNT; at the other end, the yield is equivalent to around 150 kt.
So, yes - you can simply punch in the yield you need for the job. No spreadsheet necessary. This can be done IN-FLIGHT!