Radiological Protection from Naturally Occurring Radioactive Material (NORM) in Industrial Processes


Draft document: Radiological Protection from Naturally Occurring Radioactive Material (NORM) in Industrial Processes
Submitted by Rick Tinker, Australian Radiation Protection and Nuclear Safety Agency (ARPANSA)
Commenting on behalf of the organisation

Comments on the ICRP draft document Radiological Protection from Naturally Occurring Radioactive Material (NORM) in Industrial Processes

Background of ARPANSA

ARPANSA is the Australian Government’s primary authority on radiation protection and nuclear safety. A component of our purpose is to regulate Commonwealth entities and to promote national uniformity in the approach to regulation in Australia. While the regulation of NORM activities are largely undertaken by state and territory regulators in Australia, ARPANSA oversees the development of radiation protection standards and publishes the radiation protection series of documents in consultation and collaboration with all jurisdictions of Australia. These documents draw on the recommendations of the ICRP and safety standards and guides produced by the IAEA so it is important that guidance at the international level is consistent and implementable.

General comments

ARPANSA appreciates the effort that ICRP has taken in preparing this document, and acknowledges that the recommendations in this document are seeking to address a topic that presents many challenging and complex issues that are associated with managing NORM in industrial processes. ARPANSA agrees with the guidance that NORM in many industrial activities is frequently one of many hazards, therefore there is a need for an integrated approach; we also agree that the application of the graded approach is an essential and modern approach to implementing the radiation protection requirements for NORM management. The principle of optimisation and the use of the appropriate dose criteria from ICRP publication 103 to ensure the implementation of a protection strategy is of great value in this publication. However, there are some fundamental flaws in this document as it stands and if published without change would potentially lead to confusion among regulators and the industries who may need to take this guidance in to consideration.

Definition of existing exposure situation

It is noted that in this document an existing exposure situation is defined as: An exposure situation resulting from a source that already exists, with no intention to use the source for its radioactive properties, before a decision to control the resulting exposure is taken. Decisions on the need to control the exposure may be necessary but not urgent.

This definition has changed from that published in ICRP 103, namely: A situation that already exists when a decision on control has to be taken, including natural background radiation and residues from past practices that were operated outside the Commission’s recommendations.

ARPANSA does not support this new definition, and in particular the addition of the phrase “with no intention to use the source for its radioactive properties,”. This would mean that some industrial activities and processes which are known to concentrate NORM are automatically classified as existing exposure situations. Examples of such activities include mineral sand and rare earth mining and processing, which, depending on the concentration of radioactive materials in the waste products, may be considered planned exposures by some regulators. If this new definition is published it would also be in conflict with ARPANSA’s recently published guidance in Australia for Radiation Protection in Existing Exposure Situations. RPS G-2, and IAEA GSR Part 3.

It would be helpful if the ICRP 103 definition were retained to enable regulators the flexibility to manage these industrial processes under the regulatory framework for planned exposure situations if necessary.

Existing vs Planned exposure situations

ARPANSA acknowledges that the ICRP considers NORM activities as existing exposure situations. Classifying all exposures to NORM as an “existing exposure situation” for every industry and situation is confusing and has significant impacts on the regulation and implication of radiation protection in NORM industries. The practical implementation of a NORM industry practice (existing versus planned) will probably not be so much different (in both cases, the first step is an assessment of the exposure and, according to the results of this assessment, the choice of appropriate protective actions), some clarification or recommendations (for instance, an additional explanatory paragraph in Section 3.1) may be required on how to resolve both points of view in practice.

The inconsistency in glossary definitions has also been identified for the definition of emergency exposure situations, planned exposure situations, reference level and a number of other terms.

Exclusion of radon from the NORM guidance

ARPANSA recommends that radon is included in this document rather than excluded. NORM exposures are often dominated by radon in many NORM industries, and the manner in which this document is currently drafted it has the potential for industries to omit the radon exposures or treat them separately. When considering NORM as part of the integrated approach to assessing all hazards, radon should be considered explicitly and the graded approach should be used in assessing controls. It is recommended that Tables 2.1 and 2.2 are updated to include examples of dose assessments for workers and the public that include exposures to radon. This will highlight the importance of considering NORM (including radon) in industrial processes. By only referring to ICRP Publication 126 the importance of the radon exposure pathway has the potential to be lost as there are not equivalent values for radon as those in Table 2.1 and 2.2. The exclusion of radon may lead to a lack of focus on the importance of NORM exposures.

While we acknowledge that the ICRP has other publications that provide recommendations for radon management, these should be cross referenced at appropriate points in the document where additional guidance and clarity is required.

Specific Comments

Page 5

Suggest that the first dot point be replaced with: “The Commission’s system of radiological protection applies to all controllable exposures from both natural and man-made sources. Radionuclides from natural origin are ubiquitous in trace amounts; the present publication applies specifically to naturally occurring radioactive material (NORM) associated with industrial processes that may increase the radiation exposure to individuals or affect the environment.”

Practices such as mineral sands and rare earth mining and processing have the potential to enhance concentrations of NORM to the level where regulation as a planned exposure situation may be required. The current text does not support the regulator to make this assessment if required.

The fourth main point can be improved to read as follows: “NORM presents no real prospect of a radiological emergency leading to tissue reactions or immediate danger to life, but may pose an issue of environmental contamination and occupationally exposed workers.”

Para 3 Line 146

Consider replacing the words “as well as lead to” with “and may lead to”

Para 23 Lines 313-318

These exposure scenarios should either be wrapped into the exposure pathways shown in Para 24 or include the pathway in the description:

i.e. The range of process broadly leads to three scenarios for radiation exposure:

External exposure from large quantities……

External exposure from small…..

Internal exposure from……..

Para 24 Lines 319 – 333

See above comment, better definition of sources. Consider inclusion of comment regarding volatilised fumes.

Para 24 Lines 323 – 324

Consider adding a comment on engineering controls prior to the personal protective equipment i.e. “The potential for internal exposure is governed mostly by the way NORM occurs in the workplace, the engineering controls in place for dust/fume and the personal protective equipment worn by workers”

Para 26 Line 364

‘millisievert’ is in words. Consider using units ‘mSv’ to get consistent throughout the document.

Para 30

This paragraph does not read well and should be restructured to get the point across. Suggested example as follows:  

‘By-products and residues from one industry involving NORM can be used as feedstock by other industry involving NORM and/or in common practices (e.g. building materials). In that sense, after being brought to the surface (or introduced into the industrial sector by other means), NORM enters an endless cycle (i.e. NORM can be moved and/or reprocessed from place to place). Therefore, the enhanced exposures due to NORM may occur during all stages of this cycle.’

Para 32

The definitions of existing, planned and emergency exposure situations are not in line with the quoted reference in Para. 176 of Publication 103 (ICRP, 2007a). These definitions have changed in this draft publication and are not correct.

Para 35 line 451

Re-structure sentence as follows:  

…industries involving NORM. This is due to economic importance of industries, large…

Para 36 line 467

…exposure situation, but releases and discharges may result in environmental damage and public health consequences.

Para 39 line 485

…classified as occupationally exposed should still have their radiation exposure considered. In such case,…

Para 41 line 496

needed for radiological protection purposes.

Para 55 line 599-600

…103 (ICRP, 2007a). and with the possibility that the reference level could be lower than 1 mSv per year….

This statement is fundamentally inconsistent with ICRP Publication 103.

Para 55 Lines 614 – 615

Consider removing the use of the words “very rarely” and incorporating “exceptional circumstances” or similar. 

The statement ‘a few mSv per year’ is confusing. Is this a few mSv per year above background? Clarification is required to reduce confusion and avoid implementation issues.

Para 62

The first sentence of this paragraph is obscure and does not add value. Consider removing or rewriting this paragraph.

Para 73 Line 734

Same as the comment for para 55. Consider removing the use of the words “very rarely” and incorporating “exceptional circumstances” or similar.

The statement is confusing ‘a few mSv per year’. Is this a few mSv per year above background? Clarification is required to reduce confusion and avoid implementation issues.

Para 94:

It would be good to see some additional information in here re: PPE must be maintained, personnel must be trained in its use.

Para 96:

Consider adding the word ‘should’ into first sentence to read, “Where doses are well above a few mSv per year, individual dose assessments should be undertaken.”

Para 125 Line 1078:

Replace reference to dust masks with “respiratory protection”

Glossary

Terms in glossary for emergency, existing, medical and planned exposure situations are not in alignment with the glossary terms of ICRP publication 103.  Please review all glossary terms for consistency with other ICRP publications.


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