Writing responsibilities for the Mark-1 design report:
- (Krumwiede/everyone) Solidworks, working with Jae and Alex. There are a huge number of areas where more work is needed to develop the plant CAD models and put together figures for the report. This is an area where it makes sense for us to continue to meet routinely and discuss design features.
- (Cisneros/Munk) On the fuel pebble and core design, we need to complete the information in Table 2-1, page 18. There is one key question, which is whether we can get a fuel design that uses 8% enrichment to work. As discussed in the report, at 8%, there will be enough different suppliers available that one should be able to procure SWU at only a slightly higher price than the cost of SWU for LWRs. Above 8% the number of suppliers drops, and one risks having to pay much higher prices to purchase SWU. Since one will have more direct control over the costs of fuel fabrication, the burn-up, fabrication cost, and other penalties associated with 8% enrichment are probably worth accepting, at least in the near term, if a workable 8% design can be developed.
- (Andreades) Power conversion. We’ll need to fill in sections in the power conversion chapter.
- (Zweibaum/Scarlat) Primary flow path pressure losses. We need to fill in the section on the primary coolant with a description of the flow path and discussion about pressure losses, since keeping them low is key to being able to use the gas-gap isolation.
- (Laufer) Outer radial reflector and lower core support ring and center reflector support ring design, working with Alex.
Writing responsibilities for the design basis document (older notes):
- Nicolas: DHX, DRACS Loop, Control Strategy
- Raluca: primary coolant flowpaths, tritium management system
Action items for design:
- Shut-down flow routing, and DHX flow routing; upflow vs. downflow in the defueling chute, when we go from high velocity to low velocity.
- Establish SW-COMSOL coupling – Jae and Alex
- controlling and predicting the temperature and temperature gradients to which metallic components will be exposed
- predict levels in the stand-pipes, with pump on and off.
- pressure losses through the core (pebble bed + inlet/outlet flow paths)
- passive shut-down: 20-30s passive rod insertion is needed. calculate flow residence time upstream of passive rod.
- stacking problem – can we shorten the defueling chute and lower the lid?
- DRACS design? NDHX elevation – above the refueling deck?
- elevations of components wrt to control rod drive system; radiation level coming up throught the control rod channels? how do we keep cold gas downflow on control rod drive, to keep fluoride salt vapors from coming up through the tube, and freezing and plugging things up.
Action items for Core SW:
- Stacking problem
- fix elevation & double check volume – faulted level – need cavity porosity from Peterson, cavity volume from Nicolas (based on SW), in-core salt volume vs. elevation from David (based on SW)
- piping to cold legs
- piping to hot leg
- Cold Legs – add toruses as bulges on the outside of the reactor vessel, to distribute fluid into the downcomer
- Control rod channels – show one fully inserted rod, show one fully pulled rod
- S/D blades – show one fully inserted blade, show one fully pulled blade
- Refine inlet plenum design, and ensure that central reflector can be pulled as one piece.
- Consider Option 2 again for coolant flowpath. See discussion.
Action items for GT design:
- New hot gas casing: flow area big enough?
- New hot gas casing: flow area for heated air from 1st & 2nd turbine blades to reheater
- Pipe lines connecting GT, CTAH and HRSG: do we still want this change?
- Length limitation on GT (shorter the better?)