The ONR have published their review of the Wylfa off-site planning area. (Ref). This is another rather odd decision where they have chosen to increase the area in a way that includes a significant increase in affected population despite the fact that the nuclear reactors are now shut-down, depressurised and cooling.
The ONR PAR agrees with the operator that the REPPIR test for inclusion in an off site plan extends about 900m from the reactors. Setting a planning zone of 1 km, which might seem sensible, would include about 14 people. However, ONR argue that this is not enough people for any plan to be credible so they set a larger zone including the homes of over 1000 people.
Crazy.
Suffolk has rendered the stretching of planning zones meaningless by sensibly reducing the size of the automatic countermeasure zone around the Sizewell sites when Sizewell A dropped out REPPIR off-site planning despite the ONR increasing the size of the REPPIR off-site planning zone for Sizewell B. So now we are not sure what the area ONR defines is for.
Pointless.