I don't understand the concern about refueling... The process is really simple.
You only startup 25 units per day... So it takes 12 days to get the entire 300 units up and running. When it comes time to do the 6 months refueling, you only refuel 25 per day and the reserve units are more than enough to handle the job. In two weeks, you're all done with the refueling and you're good to go for another 6 months... And even if you did start them all up in one day, but only do 25 refuelings/day, so what if you're 2 weeks over 6 months to complete the refueling... I think there's more than enough un-reacted Ni to last that extra 2 weeks while your busy refueling. -Mark