Yep, Core's going to need some cash from somewhere. They have a company called Morgan Stanley working on a solution. What MS will come up with and when its unclear. Core have however advised that they have sufficient cash to complete this process. "Cash balance of $30M [at 31 March] sufficient to support near-term working capital requirements and the advancement of a funding solution"
While some of the past timelines from Core have had BP33 production timelines down at 6 months, something nearer one year from FID to positive operational cashflow is not unreasonable working assumption. The picture below looks at the operational cash expenditure from DFS / FID through to generating cash in the context of Core building and commissioning its Grants operation and associated DFS plant. Costs will be higher this time around because there is the C&M support of existing plant. The C&M is maintaining the DMS in a restart ready condition so the plant re-commissioning timeframe should be short - possibly very short.
I'm not sure where your $100m figure comes from but its massively higher than what Core consumed as working capital in their original restart (which was far from plain sailing). One of the key factors is that there is a significant lag between the operational acts that incur the expenditure and the cash flow where its paid for. Have you accounted for that?
One of the critical factors will be payment timing in the presumed new offtake that Core is working on. If this involves a primary payment when product is landed in China then there is a multi-month production cost working capital requirement. If this involves primary payment upon loading onto a ship then working capital requirements are reduced by ten's of millions.
