I agree with Augustin Janssens and Tony Colgan that the draft document is not in line with international standards with regard to the protection of workers.
As pointed out by Tony Colgan, the definition for occupational exposure that is used by the ICRP differs from that of the IAEA. The addition "..as a result of situations that can reasonably regarded as being the responsibility of the operating management" (para 104) causes quite some confusion in the text of the draft document. It can be concluded from the draft text that for workplaces where radon exposure is adventitious the resulting radon exposure is not the responsibility of the management. Nevertheless, the optimisation process for protection of the workers should be implemented, using a reference level of 300 Bq/m3. According to para 106, the responsibiliy of the employer should be exercised by the regulatory or standardised framework laid down for the control of radon exposure in buildings. Strictly spoken, this is in contradiction with para 104.
The choice of the reference level in terms of activity concentration (300 Bq/m3) corresponds to a dose of 10 mSv/y. This is in accordance with the recommendation in the ICRP Statement on Radon, issued in 2009, for dwellings, i.e for the protection of the public. It is not clear why ICRP chooses the same reference level for workplaces. As Tony Colgan pointed out is his comment, this corresponds with a dose of 3 mSv/y. It is a remarkable deviation from the earlier recommendations of the ICRP with regard to the protection of workers, for which no plausible arguments are given. It is also in clear contraction with the Statement on Radon, wich states that "in Publication 103, the Commission considered that the internationally established value of 1000 Bq m-3 might be used globally in the interest of international harmonization of occupational safety standards". Such an approach, where protection standards for the public are also used for the protection of workers, might create a precendent with unforeseen implications.