HMS Astute Grounded

[XabbaRus]

Ok comments like that really annoy me.

Talking about splitting hairs. Radiation falls off with range quite quickly. As long as the pipes didn't break and the coolant didn't leak then there has been no incident.

However the wingnuts at CND don't realise that, they just assume that as soon as a nuke boat has a bump or something that that is proof nuclear powered vessels are more dangerous and at risk as if the fact they are nuclear makes them more likely to have an accident. I'd say that the bumps and scrapes that commercial shipping have had over the past decades have caused more pollution than nuke boats.

What the russians did yes is nuts, but then that is their business.

[Catfish]

Hello,

Originally Posted by XabbaRus

Ok comments like that really annoy me.

Talking about splitting hairs. Radiation falls off with range quite quickly. As long as the pipes didn't break and the coolant didn't leak then there has been no incident.

Well i thought here at subsim i could be a little polemic

I know that radiation falls away quickly, and this was no "incident". However what do they do after the boat's or other's life cycle(s) ? Clean the steel plates with soap ? The reactor housing, or the fuel rods, make small pellets and seal them in glass masses to bury ? If they do that at all, and just don't sink the waste in a fishery area.
I just said that nuclear propulsion is not a "clean" technology if taking energy balance, including building and disposing, into account.

A breaking-up super tanker or disposing marine fuel residues into the sea has a more direct effect, i agree.

Greetings,
Catfish

[Jimbuna]

Did anyone notice the amount of crap that has already attached itself to the hull just below the surfaced waterline?

[Jimbuna]

Originally Posted by TarJak

I can vouch for all 3 of Jim's statements of fact here.

I resemble that remark

[Oberon]

Originally Posted by jimbuna

Did anyone notice the amount of crap that has already attached itself to the hull just below the surfaced waterline?

Aye, it doesn't take long...I wonder how it affects sonar performance and signature...

[Jimbuna]

Originally Posted by Oberon

Aye, it doesn't take long...I wonder how it affects sonar performance and signature...

Me too...but I should imagine it is the same for all subs.

[Oberon]

Originally Posted by jimbuna

Me too...but I should imagine it is the same for all subs.

Indeed, I should imagine they get a scrape down or whatever the navy uses, when they put into drydock, perhaps for degaussing.

Interestingly though, on having a quick scan to see how the navy cleans the underside of its boats I came across talk of sharkskin inspired artificial coatings which might prevent algae and the like from adhering to the hull of a vessel. Perhaps this may have a future.

http://www.sciencedaily.com/videos/2...at_surface.htm

Or...perhaps not, it is possible that this 'sharkskin' due to its design may create cavitation, however for surface ships this is not so much of a problem.

[TLAM Strike]

Originally Posted by Oberon

Indeed, I should imagine they get a scrape down or whatever the navy uses, when they put into drydock, perhaps for degaussing.

Interestingly though, on having a quick scan to see how the navy cleans the underside of its boats I came across talk of sharkskin inspired artificial coatings which might prevent algae and the like from adhering to the hull of a vessel. Perhaps this may have a future.

http://www.sciencedaily.com/videos/2...at_surface.htm

Or...perhaps not, it is possible that this 'sharkskin' due to its design may create cavitation, however for surface ships this is not so much of a problem.

That red or green paint you see on the under side of ships is called anti-fouling paint, it makes it difficult for marine organisms to latch on but it doesn't always work and the paint only remains effective so long before stuff starts growing what had managed to latch on. When the paint stops working and you don't bother cleaning the hull it starts to look like this...

[XabbaRus]

Ah catfish I agree to a point but if you take life cycle processes into account nuclear energy against such as wind power is per kilowatt of power less polluting, CO2 wise anyway.

Also the waste if dealt with properly shouldn't be too bad.

[Bubblehead Nuke]

Sorry to take so long to replay, life got in the way.

Radiation will always be present in a fully cored reactor plant. There are both long lived and short lived transuranics that will continue to give off some amount of radioactivity for some time. This boat, being VERY new will have almost NO residual radition that will be detectedable outside of the hull after a reactor scram. Please note that this is Gamma/Neutron radiation. As the plant accumulates long lived transuranics due to plant power range operations that amount of residual plant radition will increase. The measurable effect outside the shielded volumn is very minor.

There is NO release of radioactive material in this kind of incident. Just not going to happen as long as the pressure hull is intact.

About the shielding:
Shielding is HEAVY. You want just enough to do the job and nothing extra. During the operational life of the boat there will be people in front of and aft of the plant. Therefore there is shielding to protect those people. As there is nobody outside of the hull there is no reason to put shielding there. The surrounding water provides adequate shielding for low power pierside ops. There is SOME shielding in the top of the reactor compartment to protect those walking above it during power range ops when surfaced or when people need to be topside. Seeing as everyone is either inside the hull or far enough away during higher power operations there is no need to have much shielding for topside.

I suggested that the plant was scramed for the protection of those topside and for the surrounding support ships that would have come to its assistance. At the distance from shore, I would not expect any danger to those standing on the beach. A source high enough to hurt someone at that range would FRY the crew in minutes.

There are other operational issues that I could discuss, but unfortunately they are NNPI and therefore off limits.

A note to Catfish:
The water in the plant does not become radoactive. It is the impurities that are are suspended in the water that become radioactive. If you filter them all out you can DRINK the water with ZERO effects. Other materials become radioactive due to Gamma/Neutron bombardment. Over time they lose this property by the halflife of the material that was activated.

What you state about it no being clean is untrue. If you measure waste production from beginning to end, nuclear power is the cleanest of ALL the non-renewable power sources. The amount of waste materials is in the tons per plant over its LIFETIME. Dangerous yes, but VERY small in actual amount.

Anything that burns is measured in the HUNDREDS of tons a YEAR of hazardous waste material produced. If you compare the amount of waste generated vs the amount of power produced it is a no brainer.

[Jimbuna]

Originally Posted by TLAM Strike

That red or green paint you see on the under side of ships is called anti-fouling paint, it makes it difficult for marine organisms to latch on but it doesn't always work and the paint only remains effective so long before stuff starts growing what had managed to latch on. When the paint stops working and you don't bother cleaning the hull it starts to look like this...

Rgr that....used to lift my dads fishing boat out of the water each year to blast the old off and re-apply the new.

The most expensive paint I have ever come across by a long way and strange as it may seem, the boat had to be back in the water within 24 hours of the paints application (before it dried) to be effective.

[ETR3(SS)]

Originally Posted by Oberon

Aye, it doesn't take long...I wonder how it affects sonar performance and signature...

It creates flow noise around the hull due to the irregularities of the hull shape now. It can also slow the boat down by a knot or two. Usually about once a year or two you would drydock and pressure wash all the growth off. Then when you take her out to sea again she feels like a dragster.

[XabbaRus]

in reply to bubbleheadnuke, given you obviously can't tell us those details and I respect that, is this site monitored by those people who would kick your ass in jail?

I'm imagining yes as I have heard that the keypublishing aviation forum is monitored by the security services.

Just curious.

[ETR3(SS)]

I'm not sure if the site is monitored or not by the Navy, but there's enough submariners on this site that one of us would see it and know. While I can't speak for the others, if I saw something leaked here I'd report it to the appropriate authorities. Not trying to answer for Bubblehead Nuke, just giving my input.