First, reactor protection systems will start reducing power down to 40% nominal if the turbogenerator load disappears (search for URB in https://inis.iaea.org/c

First, reactor protection systems will start reducing power down to 40% nominal if the turbogenerator load disappears (search for URB in https://inis.iaea.org/collection/NCLCollectionStore/_Public/34/083/34083100.pdf https://inis.iaea.org/collection/NCLCollectionStore/_Public/...). The power would not be dumped into a resistor: the power would be dumped in form of heat with the turbogenerator disconnected from steam. I expect that you can "just" dump it in the condenser and use the standard cooling of the condenser to dump it into the local body of water. If that's insufficient, one can dump steam from the secondary loop into atmosphere (which necessitates adding water there). You can play with a vver-1000 simulator and see how many of these things work; the simulator whose manual I'm citing above can be easily found on the internet.