I don't suppose if you know what the BCR of the Valley Lines is? I'm sure it's been written down somewhere but I can't for the life of me think where.
It's in the Wales RUS, Gap/Option 15 (dated 2008).
A BCR figure of 1.2 (page 131) relates to long-term growth on the Taff Vale and Rhymney lines. This would put 16tph through Queen St rather than the current 12tph.
There is a BCR of 0.3 shown for doubling services (1tph to 2tph) on the Vale of Glamorgan line (page 125).
All of the RUS is couched in the standard NR-speak of investigations into projects for which they had no expectation of funding or provision of rolling stock.
The main mention of electrification in the Wales RUS relates to Wrexham-Bidston, the one option which has since disappeared without trace.
Valleys electrification gets a throw-away remark about "longer-term aspirations" linked to GW electrification (then approved only to Didcot).
The Valleys are Option A15 in the Electrification RUS (Oct 2009), but does not get a BCR as it is not a "high-ranking gap A scheme" like NW/TP/GW/MML.
So here we are four years on with the RUS turned on its head.
In fact many of the RUSs have been quickly obsoleted by the electrification announcements and the recent HLOS.