Overall no significant comments, and the document provides some useful guidance and references.
In terms of managing radiation exposure it would be amiss of anyone to ignore well known and well defined areas of radiation exposure in the industries identified in the document, however its addition is welcome. The consideration of that these are “existing” exposures is not aligned with other agencies providing guidance in such fields, however in terms of managing the radiation exposure this should not have significant impact.
Section 2.1 Ubiquity and variability
Two considerations for addition to this section:
Seawater Injection System/s: It has been observed that the processing of seawater for use in enhanced oil recovery methods has produced biofouling on pipework which has enhanced levels of natural uranium. [SPE 73959 Technologically Enhanced Naturally Occurring Radioactive Material Associated with Sulfate Reducing Bacteria Biofilms in a Large Seawater Injection System, Bird et al refers]
Abrasive Blasting, Proppant & Refractory Materials: These could be considered under building materials in the case of refractory, however in many cases cements are mixed on location with the potential for worker exposure and localized contamination. Both abrasive blasting (Garnet) materials used to prepare surfaces and proppants used in fracking operations can provide routes for worker exposure and localized contamination if not handled properly.
Table 2.1 Examples of dose assessment for workers (external and internal from dust, excluding exposure to radon)
The line items for Oil and Gas Production, Onshore and Offshore, it would be useful to have a reference for these, particularly due to the factor of ten difference between them when handling the same source material.
Section 3.1.2 Categories of Exposure (43)
As it has been previously indicated that work in these industries are treated as existing exposure/s, in this section it is stated “environmental exposure is dealt with on the basis of common environmental standards, starting with an environmental impact assessment (EIA) considering the presence of NORM”, should EIAs therefore be carried out retrospectively where operations are already mature, and then re-evaluated at regular/routine frequencies?
Section 3.3 Optimisation of protection
The use of collective dose can be misleading and is relative to technology and culture of the operating environment. In some poorer countries more direct hands on operations involving large numbers of workers may be employed.