With Labour trying to face several ways at once it looks more like chaos as the front bench tries to please everybody and fails to satisfy anybody at the same time.
Jeremy Corbyn is quoted (quite rightly in my view) as saying that 'Tories have just put up the cost of your electricity by giving a blank cheque to EDF for a power station that doesn’t work' See: https://dwpexamination.wordpress.com/2016/07/31/jeremy-corbyn-facing-backlash-from-unions-momentum-activist-and-shadow-business-minister-over-hinkley-c-nuclear-opposition-huffington-post/
On the other hand, Labour's energy spokesperson Barry Gardiner is said to be in favour of the Hinkley C power station but at a lower cost to the consumer. See Ian Fairlie's piece at:
How to reconcile these two views? Well, you could say that Labour wants to pay a slightly lower price for a power station 'that doesn't work'. Alternatively, you can just choose the particular policy that comes closest to your particular taste. That's one way of running a political party I suppose, though even (nay, I say, ESPECIALLY) the Green Party has somewhat more coherent policy responses than Labour!
As for the trade unions, well that depends on whether you are a French union or a British one. The British trade union position is that it's ok if somebody else pays for Hinkley C, and of course the French unions are opposing the deal because they know that they will end up paying a lot of money (and jobs) for it!
Of course, as Ian Fairlie argues, there's plenty of jobs in alternative clean energy sources to Hinkley. One estwhile Momentum supporter has attacked Corbyn as being an 'anarchist' for his position on Hinkley. Well, I'd more see the Labour position as being much closer to chaos! There's a big difference!