[ROCKLOBSTER]

The DWH gear was "fly by wire" as opposed to wireless, since radio doesn't work well under water.

Regarding what you said about "hardened electronics":

I'm not sure if there is a lot of electromagnetic wave activity around such intense radiation (if so, I always wondered why they bothered to make steam instead of harnessing the radiation to make power) or if the radiation actually damages the chips etc by changing their atomic structure.

It's pretty likely that "hardening" would probably entail quite a bit of lead shielding in the form of cases for the controls, and maybe the cable too.

If cables are not needed, that would make life a lot simpler for the engineers.

[Errant]

or if the radiation actually damages the chips etc by changing their atomic structure

It works something like that. Radiation hardening: https://en.wikipedia.org/wiki/Radiation_hardening.

[Greysard]

I'm not sure if there is a lot of electromagnetic wave activity around such intense radiation

γ radiation is high frequency photons, or radio waves above 10 exahertz (10¹⁹ Hz.) So there is a lot of EM waves around a γ source.

or if the radiation actually damages the chips etc by changing their atomic structure.

Yes. Ionizing radiation is directly affecting atoms, and it causes electronics to fail. Per Wikipedia:

Environments with high levels of ionizing radiation create special design challenges. A single charged particle can knock thousands of electrons loose, causing electronic noise and signal spikes. In the case of digital circuits, this can cause results which are inaccurate or unintelligible.