Search found 4758 matches

by Cyril R
May 29, 2018 1:16 am
Forum: Water-Cooled Reactors
Topic: GE-Hitachi BWRX-300
Replies: 11
Views: 4144

Re: GE-Hitachi BWRX-300

They can't get SiC-SiC to work in a BWR chemistry at the moment, turns out it is considerably more oxidising than what you find in a PWR and it just can't handle it, at least not yet. So we are stuck with Zircalloy or ODS steel. My now ongoing masters dissertation involves U-Mo alloy for HWRs, and ...
by Cyril R
May 28, 2018 1:33 am
Forum: Water-Cooled Reactors
Topic: GE-Hitachi BWRX-300
Replies: 11
Views: 4144

Re: GE-Hitachi BWRX-300

They can't get SiC-SiC to work in a BWR chemistry at the moment, turns out it is considerably more oxidising than what you find in a PWR and it just can't handle it, at least not yet. So we are stuck with Zircalloy or ODS steel. My now ongoing masters dissertation involves U-Mo alloy for HWRs, and ...
by Cyril R
May 27, 2018 8:47 am
Forum: Water-Cooled Reactors
Topic: GE-Hitachi BWRX-300
Replies: 11
Views: 4144

Re: GE-Hitachi BWRX-300

Well they might just have posited a LOCA where the silo just fills with water/steam and the core remains covered. Sure, but this would require equalization between the RPV pressure and the containment - somewhere between zero and 7 MPa. IOW designing the containment for much higher pressures than u...
by Cyril R
May 27, 2018 7:14 am
Forum: Water-Cooled Reactors
Topic: GE-Hitachi BWRX-300
Replies: 11
Views: 4144

Re: GE-Hitachi BWRX-300

Some info here: https://gain.inl.gov/SiteAssets/EARMSPresentations/05Ball-GE-H,Mar2018.pdf Looks like a further simplified ESBWR. They could probably simplify some more by replacing the ICS with the Kerena reactor's emergency condenser and PPPTs for passive switching operations. Interesting claims o...
by Cyril R
Feb 24, 2018 10:18 pm
Forum: Water-Cooled Reactors
Topic: Canadian pressure tube SCWR
Replies: 9
Views: 2905

Re: Canadian pressure tube SCWR

The highest grades of austempered ductile iron have a continuous service temperature of 260C or so, and if we use Atucha as an example the maximum moderator temperature will be about 220C, so in theory no insulation is needed inside the vessel. Passive insulation can be provided between the compres...
by Cyril R
Feb 21, 2018 4:04 pm
Forum: Water-Cooled Reactors
Topic: Canadian pressure tube SCWR
Replies: 9
Views: 2905

Re: Canadian pressure tube SCWR

On a slight aside I am currently looking for someone at my university to let me do my MSc dissertation on a pressure vessel heavy water reactor using a pressure vessel made of prestressed austempered ductile iron. The vessel ends up sufficiently large, and the price of heavy water in real terms is ...
by Cyril R
Feb 20, 2018 4:40 pm
Forum: Reactor Materials and Fluids
Topic: Concrete free power plant
Replies: 7
Views: 2128

Re: Concrete free power plant

Problem with using water - beyond the bulk - is that you would have to account for what happens if you actually evaporate the water, or it leaks. In an accident you could be faced with having to abandon parts of the reactor building, even if the fuel hasn't actually failed yet. This would depend on...
by Cyril R
Feb 20, 2018 4:38 pm
Forum: Water-Cooled Reactors
Topic: Canadian pressure tube SCWR
Replies: 9
Views: 2905

Re: Canadian pressure tube SCWR

I've been very interested in the PT-SCWR for a long time. The high efficiency pressure tubes (where the load bearing segment is in thermal contact with the calandria and not the coolant) they propose are far more likely to be practical, in my opinion, than the enormous pressure vessels that pressur...
by Cyril R
Jan 15, 2018 4:30 pm
Forum: Reactor Materials and Fluids
Topic: Concrete free power plant
Replies: 7
Views: 2128

Re: Concrete free power plant

You could also use water as a filler and shielding material. Even cheaper than lead, and it could do double duty as emergency heat sink.

Water here, water there, water everywhere... and not a drop to drink!
by Cyril R
Oct 01, 2017 1:33 pm
Forum: Reprocessing, Transmutation, Waste Storage
Topic: Yucca Mountain
Replies: 181
Views: 32773

Re: Yucca Mountain

... Fission products could be buried in boreholes along with most of radioactivity. ... Why bother with bore holes? Cement it into the bottom of the mine it came from and let it decay naturally. The experience from the Oklo nuclear reactors proves that you can store this stuff just about anywhere y...
by Cyril R
Sep 27, 2017 4:46 pm
Forum: Reactor Materials and Fluids
Topic: Microtube Heat Exchangers
Replies: 11
Views: 2154

Re: Microtube Heat Exchangers

I imagine QC on a monobloc casting would be primarily empirical. If it performs on a test rig and passes pressure proofing it would be accepted, even if some airfoils are out of tolerance Good point. You may be right about this - pressure and flow test could be the manufacturing QC. Current standar...
by Cyril R
Sep 27, 2017 3:44 pm
Forum: Reactor Materials and Fluids
Topic: Microtube Heat Exchangers
Replies: 11
Views: 2154

Re: Microtube Heat Exchangers

Apparently a team at Sandia believes it might be possible to cast an airfoil PCHE type structure in a single piece as the lack of discrete channels allows the casting cores to interconnect. Apparently called 'Cast Metal Heat Exchanger' / CMHEs and projected to see an 80% reduction in costs for simi...
by Cyril R
Sep 27, 2017 10:28 am
Forum: Reactor Materials and Fluids
Topic: Microtube Heat Exchangers
Replies: 11
Views: 2154

Re: Microtube Heat Exchangers

I think the idea here is that whilst you need huge numbers of tubes, they are all functionally identical and can be chopped off the end of a continuous manufacturing line. Same with the tubesheets, hundreds of thousands of absolutely identical parts. And turning out millions of relatively simple an...
by Cyril R
Sep 27, 2017 10:19 am
Forum: Fluoride Reactor Design
Topic: Congratulations to David LeBlanc (ORNL)
Replies: 147
Views: 33021

Re: Congratulations to David LeBlanc (ORNL)

A quick Google search tells me that your cost estimate for fuel is close enough to real numbers that I'm not going to dispute it. A quick Google search also tells me that the typical rate for electricity in the USA is about 10 cents/kWh and that the typical profit margin for electricity is less tha...
by Cyril R
Sep 26, 2017 5:17 pm
Forum: Reactor Materials and Fluids
Topic: Microtube Heat Exchangers
Replies: 11
Views: 2154

Re: Microtube Heat Exchangers

One concern that springs to mind is the large number of joints in this type of exchanger. Failure rate better be nil. If you have a million joints, a 10-5 joint leak reliability means average of 10 failures per year. Not good. In terms of cost, can't imagine that tiny tubes would be cheaper than pla...