Upper core internals
- With the 3 DHXs in the space between the inner and outer lids, there is significant room for pebble handling containers.
- Refueling deck could be thinner (1 m rather than 2 m; higher at the bottom, same at the top) and add steel or lead locally where additional shielding is needed.
- Fill tank: needs to be big enough to hold whole DRACS salt inventory. Locate it inward compared to TCHX (needs to fit in footprint of DRACS hatch).
- Hot and cold leg should not penetrate the RV wall if we want to mount the DRACS modules on frames. Extend upward (above cap).
- Hot and cold leg elbows should be bends.
- Space out the TCHXs 120° rather than 90° (Aligned with DHXs).
- Frame should be key shaped structure going through cavity cap. Reactor will have to be defueled when pulling out the DRACS (breach in containment).
- Condenser can be on the outside, at the base of the chimney structure, at grade level.
- Water tanks for makeup water: look at ESBWR design. Bottom can be aligned with bottom of TCHX. Shape doesn’t matter. Locate inside key shape, inside containment, against wall.s
- Partition the water tanks with independent valve systems so that if a line breaks, they don’t drain completely.
- May want to change the shape of the reactor cavity wall to key shape (not flat walls everywhere but rather circular walls where not interfering with hot/cold leg of primary system.
- Having flat outer walls of the cavity would help for manufacturing (cf AP1000). Could be done by having 12 flat sections (spaced by 30°).
- Outer reactor building wall below grade could be thinner (~ 50 cm). Look at IAEA report for water proofing.