Tech chiefs face US Senate questions on internet law

As we go to air the chief executives of Facebook, Twitter, and Google begin questioning by senators over Section 230 of the Communications Decency Act, which protects web companies from liability when it comes to content posted by users. We hear from independent tech analyst Stephanie Hare on its significance. Also in the programme, the nuclear industry is pinning its hopes on mass-producing small, cheap power stations to compete with renewable energy. Our chief environment correspondent Justin Rowlatt has been to visit the headquarters of a new consortium led by the UK engineering giant Rolls Royce, which says it can manufacture a new small modular reactor in the next ten years.