5 ms·
any more recent commentaries?
by mjfl 7y ago
any more recent commentaries?
- willis936 7y agoThere would be little benefit. ITER was delayed by 20 years due to a drop of funding, so most of the primary issues to address have been put on hold. The plasma physics and machine design has seen progress, but no one has claimed that wouldn’t be the case. W7-X’s success has shifted some more funding into stellarators, but outside of that not much has changed in the landscape in the past 20 years. YCBO is still prohibitively expensive and fragile, but the use of high temperature superconductors with high critical currents would increase confinement time by a large amount.
- baking 7y agoBased on YBCO prices from a few years ago, the estitmate was $200M in material cost for the magnets of a 200MW reactor, not an outrageous amount considering all of the other costs. The real issue was getting the construction cost of the magnets down to 2x the materials cost from about the current 10x the material cost for large superconducting magnets.
- sgt101 7y agoThe other argument is that if you use YBCO then the overall scale of the development is orders of magnitude reduced.
- mjfl 7y agoA delay of a project of 20 years or more is beyond my comprehension. That's people's entire careers. That's the entire senior staff of the project dying out or retiring. That's an extremely non-negligible amount of time from a people perspective.
- pfdietz 7y agoAnd with this delay, and the decline of fission, when ITER is done there may be no tritium left to fuel any follow-on.
- pfdietz 7y agoITER was delayed because of incredible lowballing of the initial cost estimate, along with management screwups. They knew or should have known that estimate was fraudulent.
- willis936 7y agoOh? I assume you have a source to back that up. All accounts I’ve seen (wikipedia and the timeline on iter’s website) show that it is due to global politics, namely due to the US’s withdrawal (which was not motivated by finances). You seem like you have a strong narrative you’re sticking to. Is there something you’d like to disclose?
- pfdietz 7y agohttps://fire.pppl.gov/FPA13_Freidberg2_2013.pptx https://fire.pppl.gov/FPA13_Freidberg2_2013.pptx Look at the chart on page 13, and his comments on the next page.
- willis936 7y agoThat’s a retrospective look. That was not what happened in the early 2000s and is not why ITER stalled. ITER stalled because the US pulled out. You can’t change history to fit a narrative.
- pfdietz 7y agoHe is saying that if they had done due diligence, if they had honestly extrapolated the costs of previous experiments using the demonstrated empirical scaling laws, they'd have gotten costs closer to what ITER has ended up costing. They either knew or should have know the initial cost claims were dishonest. The US opted out of ITER in 1999 and returned in 2003. The cost of constructing ITER was estimated at €5B in 2006. How could the earlier US pullout excuse the inaccuracy of that estimate? Your narrative there makes no sense.
- pfdietz 7y agoWell, there's this from Abdou (2016) at UCLA (which seems to be the center in the US for the engineering side of fusion): "MTBF for Blanket/FW/PFC in any DT fusion device is estimated top be very short while MTTR is predicted to be too long -- leading to very low availability of only a few percent" http://www.fusion.ucla.edu/abdou/abdou%20presentations/2016/FPA%20Presentation-MAbdou-Dec%202016-Washington%20DC.pdf http://www.fusion.ucla.edu/abdou/abdou%20presentations/2016/... Contrast that with Stacey's optimism about reliability.