ARIES Documents -- Meetings ArchiveARIES Conference Call, 10 Aug 2006
Documented by L. Waganer
The next conference call will be on 31 August 2006.
The team is anxious to know the PPPL Review Meeting dates so travel can be arranged. Les will contact Farrokh Najmabadi to see if any progress has been made to select the meeting date.
Divertor Design - TK Mau downloaded a file to describe his current results. He continues to work with Tom Kaiser and Rajesh Maingi (LLNL) last week to improve field line tracing code to enable definition of the divertor geometry and particle density for ARIES-CS. TK's results indicate the number of particles hitting the tentative plate geometry and location was only 560 out of 1000 field lines (FL) launched. TK thought this was due to the long FL, which indicated many lines were too long to actually hit the plates. But as the FL become long, they lose their energy and have little influence on the power on the plates or elsewhere. Rather than launch the FL only at the 0° location, the launch location should also include 30°, 60° and 90° positions. The other question was the effect of the distance of the divertor plate from the LCMS. I believe TK said this data was for 30 cm offset. He said 50 cm was too far and 5 cm to 10 cm was too close. He intends to do other runs to determine the optimal distance.
A baffle plate is needed to keep the neutralized particles in the divertor region so they can be drawn into the vacuum duct. TK will check baffle design approaches for other stellarator experiments and will try to emulate those designs in his analysis.
Integrated Systems Assessment
Systems Code Analysis - Jim Lyon has been adding the data to model the advanced LiPb/SiC blanket option. Les Waganer sent him an estimate for the cost of the concrete and re-bar for the reactor building and bioshield.
Neutron Wall Loading Update – Laila El-Guebaly asked TK Mau and Xueren Wang about the extent of the divertor and baffle coverage.
Laila also reported that Paul Wilson has tested the 3-D neutronics code and it is working fine. They need the recommended scrape off layer thickness to finalize the NWL calculations. When the 3-D NWL is fully mapped, they can determine the average and the peak to average values.
Laila is generating the decay heat for the final LOCA/LOFA and safety analyses and needs the temperatures at the onset of LOCA/LOFA from UCSD.
Power Core Geometry – Xueren Wang has now modeled the tentative penetrations in the coil support structure and has calculated the stresses in these local areas. He has been working with TK Mau and Les Waganer on the auxiliary ports for the ECH/maintenance. These ports should be located on or near the horizontal midplane.
Maintenance Approach – Les Waganer is now being assisted by Rich Peipert, who is a maintenance and availability expert (although in aircraft) to increase the fidelity of the maintenance modeling. They are refining the approach to remove the shielding blocks and gain access for cutting and welding the coaxial blanket cooling connections. They have concluded that if the connections must be cut and re-welded, additional auxiliary ports will be required to allow parallel blanket removal operations while the shield blocks are removed and cutting is being conducted.
Safety Assessment – Brad Merrill has prepared a thermal hydraulic model
for several accident scenarios.