"though I can't discuss further maybe someone with a civilian background in nuclear physics can fill in"

Oh spare us the cloak and dagger. I don't think oxygen radioactivation has been classified for about 80 years now.

There's even a pretty good wikipedia page at

http://en.wikipedia.org/wiki/Isotopes_of_oxygen

The "natural" stable isotope O-16 needs to get triple neutron activated before you get an unstable isotope O-19 and the half life of that is like a minute. So its about half a million minutes per year, and its been about two years, so thats about a million half lives later... I think all the O-19 is long gone.

I do agree 100% that the "stuff" dissolved in the water is about a zillion times more important than the oxygen itself.

Its so mainstream there's some interesting radio oxygen dating work done using the Dole Effect, which also has a wiki page. TLDR is photosynthesis preferentially concentrates certain O isotopes so you can make all kinds of assumptions about glaciation and where plants are growing (ocean or land) given some 16O:18O ratios.

http://en.wikipedia.org/wiki/Dole_effect

There's even a cool wikipedia article with a UTF-8 name.

http://en.wikipedia.org/wiki/%CE%9418O

Which brings you to the greater topic of isotope geochemistry

http://en.wikipedia.org/wiki/Isotope_geochemistry

I'm sure there is at least some cloak and dagger stuff that can't be discussed but there's a simply huge amount of open literature about oxygen radioactivity. I would suspect there's more open lit stuff about isotopic geochemistry than cloak and dagger stuff.

> Oh spare us the cloak and dagger. I don't think oxygen radioactivation has been classified for about 80 years now.

I'm not trying to be cloak and dagger, otherwise I wouldn't have mentioned that a civilian trained nuclear physicist can tell you the exact answer.

However I do not have CG-RN Rev 3 completely memorized and I no longer have access to it, so unless I know for sure something is not NNPI or otherwise protected by the Atomic Energy Act then I don't discuss it. Not that I don't agree that it's pretty crazy that someone who's never been in the Navy could go and look at Wikipedia and discuss it with someone else and be just fine but that the person who's been in the nuclear Navy cannot... but then I've never attributed "common sense" to the military.

With all that said, you haven't hit on exactly what I'm talking about (not that oxygen activation isn't cool). I will say the actual answer is pretty mundane, not at all cloak-and-daggery.

"Not that I don't agree that it's pretty crazy"

Well if that's how the Navy is, then that's how it is. I was MOS 55R in the army and that's not how how we do it. Then again I was not a 55G which (was) the nuke guys. Maybe they have excessive rules, maybe not.

As for n activation of (pure) water that either the O which is harmless or the H which is almost too obvious or playing games with contaminants. Nobody uses pure water as a coolant other than maybe training/experimental/university reactors, so there's the chemical shim system (and its inevitable contaminants). Or simple mechanical contamination like household dust essentially. Or corrosion (however slow) of non-bulk parts of the reactor, iron, carbon, and chromium from the walls are irrelevant but copper ions from slowly corroding cabling or something. Good luck being nearby the ocean and not having detectable chloride ion concentration, however low. Or dissolved nitrogen from the air, argon etc from the air. Sealing/gasketing material incredibly slowly corroding away. There's more to stainless steel than just Fe/C/Cr so if you corrode enough of it... Not much other options, its a pretty highly controlled area.

It's how it is with nuclear information everywhere in the US government. If you don't know that you can talk about it, you don't.

http://en.wikipedia.org/wiki/Born_secret

It is too bad you can't say more about this, one of the fun things I got to do a couple of years ago was to stare into the pool of the Reed Research reactor running at power and look at the awesome Cerenkov radiation (that eerie blue glow, it looked exactly like this : http://en.wikipedia.org/wiki/File:Cerenkov_Effect.jpg [yes that is the actual reactor, no I didn't take this picture :-)])

I will guess: By looking at a nuclide map, the neutron flux in seawater should activate the NaCl, and produce 36Cl, 38Cl with a half life of 3e5 years and 38 minutes respectively. And 24Na with 15h half life. Additionally there may or may not be nasty reaction products, if we look at reactions of Oxygen with neutrons. ( I did not find any, but that does not mean there is none.)