B7 is the radiation unit. It has never been very popular with students. Truthfully this is a bit of a niche area – the preserve of specialists for the most part. Of course people do encounter radiation in various forms as part of their work but nothing too extreme.
The changes to this element are mostly structural.
In part 1 (nature of radiation), apart from adopting the International Diploma layout. We have a new entry mentioning the office for nuclear regulation (the regulator for the nuclear power plants).
The section on non-ionising radiation is now clearer. There’s a greatly expanded section on effects of exposure with mention of these now by name (such as Photokeratitis). The radiation risk assessment factors are taken straight from the International Diploma. The companion section on ionising radiation follows a similar logical layout. You’ll notice though that Geiger-Muller tubes and film badges have now been taken out. The outline of the legal requirements governing ionising radiation has now become more explicitly detailed.
The final section on lasers (which are mostly of the non-ionising radiation variety) is little changed. Except for the greater detail on the effects of exposure.