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

Topic

Key Observations

Recommendation

Leadership on NORM

·         NORM and its appropriate management are complex. There are many factors that need to be considered from pure risk through to public concern, to ensure a consistent international approach.

·         Radiation protection practitioners look to the ICRP for high level leadership and guidance on key issues. However, the current draft comes across as a broad collection of ideas about NORM, rather than a framework for management.

·         For example;

o   There is no clear definition of NORM,

o   The graded approach is recommended, but there is no substance on what this might look like or how it might be implemented (rather than providing broad tables on radionuclide concentrations, the ICRP might use the space to provide examples of how the graded approach is applied in various areas),

o   The document is overly complex in areas (particularly, for example, in its discussion on environmental aspects).

·         The document would benefit from providing a clearer guidance for NORM, or an approach for determining which NORM situations require control. There would be value in considering and aligning with the definitions and guidance provided by the IAEA.

ICRP to consider reviewing its approach in the document to provide a more structured framework.

Graded Approach to Managing NORM

·         It is acknowledged that the ICRP has aimed to provide guidance for countries to adopt an appropriate form of radiation protection for NORM where nothing has existed in the past. This has been done by recommending the use of an “existing exposure situation”. However, we believe that this will result in confusion at a practical level and may undermine the integrity of the “system of radiological protection”.

·         It may be more appropriate for the ICRP to provide practical advice on the application of the system of protection for materials above 1Bq/g and provide examples.

Involvement of Resources Industry

·         The document is directed towards the resources development industry, however, there appears to be a lack of understanding of the industry and little evidence of seeking engagement with the industry. Broad sector data is provided, but does not adequately capture the variation that occurs across sectors.

·         Input from the resources development industry should be actively sought.

ICRP seek to engage directly with the resources development industry for their direct input.

Planned Versus Existing Exposure Situation

·         Classifying exposure to NORM as an “existing exposure situation” for every industry and situation is confusing.

·         An example of the confusion is as follows;

o   The “existing exposure” situation applies when exposure occurs when material is being processed not for its radioactive properties. However, in many mining and processing situations, radionuclides are actively removed from process stream in order to meet quality controls. Generally, the quality control for a final product is to ensure that radionuclide concentrations are less than the exemption criteria, and therefore final products are not defined as radioactive. In these situations, the radionuclides are not being removed to be used, but they are being targeted and removed. Should this be a “planned exposure situation” ?

·         The message is that some types of radiation are OK, whereas other are not.

·         From a practical perspective, managing additional radiation exposure is important, regardless of its source or the material’s intended future use. In particular, defining a control regime on the basis of intended future use (‘being used for its radioactive properties’, or not) is illogical. In some cases the product material may be used for multiple purposes, some involving its radioactive properties, some not. Which regime would apply?

·         In most cases in practice, facilities with NORM are regulated as per a planned exposure situation (once identified – for example, uranium mining).

·         In addition, there is scope for proactively treating an operation as a planned exposure situation well in advance of the identification of any radiological hazard by anticipating potential exposures. Examples include;

o   An operation in an area of known elevated radioactivity levels, such as drilling or working in a similar geological area,

o   A facility for NORM decontamination,

o   A storage facility for NORM waste.

·         The practical requirements for planned exposure situation are clear and are more readily able to be factored into facility safety and environment management systems.

·         An important consideration is that the nature of the source is not necessarily fully understood from the outset, but potential exposures ‘can be anticipated and controlled from the beginning’ [Line 425] (i.e. these could be a planned exposure situation).

Further discussion occurs regarding the decision to classify operations with NORM as “existing situations”.

Radon

·         References to radon in the document are confusing.

·         The document generally states that radon (decay product) exposure is not to be considered, however, clause 68 refers to ICRP publication 126 in which radon is to be considered if it exceeds the derived reference level. The implication is that radon needs to be measured in the first case and then controlled if required – which is the same as it being managed.

·         From a practical perspective, radon and its decay products would mandatorily need to be considered in every underground mine situation or in surface facilities treating NORM with low ventilation rates.

Further discussion occurs regarding the decision to exclude radon.

Focus on Radiation Management Plan (RMP)

·         Section 4.1.3 of the document is entirely appropriate. This section outlines the framework for a RMP and this is the most practical method of managing radiological impacts within a facility. Note that in many operating facilities, an operator is required to develop management plans for other hazards (for example; a dust management plan). Therefore, a radiation management plan would not be something new.

·         Integrating the RMP into a broader safety management system makes practical sense.

Development of RMP’s are effective practical measures for managing NORM and should be encouraged.

Reference Levels Versus Limits

·         The document refers to reference levels which may be different from established dose limits. This is likely to cause confusion. For example, for a facility that involves NORM it is OK for the public to be exposed to a few mSv/y, however, a planned exposure situation (for example; a uranium mine) is limited to 1mSv/y and likely constrained further.

Consideration be given to aligning the advice on acceptable levels of dose.

Focus on Environment

It is appreciated that ICRP addresses the issue of the impact of NORM activities on the environment and considers EIA as a tool for assessment the effects of NORM to the environment. But there is a disproportionate focus on environment.

The recommendations regarding the approach towards the environment systematically refer to the need for performing an Environmental Impact Assessment (EIA) including radionuclides. In para. 130, the document goes even further by stating “it is necessary to perform the site-specific analysis of radionuclides with respect to their physical and chemical forms… it is further necessary to identify the mobility of radionuclides, their spatial and temporal variation, etc.". Such a detailed statement is not consistent with a graded approach.

Generally, radioactivity should be considered as a part of EIA in all facilities that process or otherwise contain NORM. However, radiological risks as part of EIA can be frequently excluded with a simplified assessment. It does not always need the consideration of all items mentioned in para 129 by ICRP in a detailed manner. Additionally, the assessment should be based on a broader perspective that covers not only radiological effects but also non-radiological effects like additional costs due to higher prices for waste disposal.

Ethical Issues with NORM

·         NORM impacts and doses are generally low.

·         An important concern is that undefined controls can result in variable and inappropriate level of attention (including; financial, managerial and regulation).

·         Additional unnecessary burdens in one jurisdiction may make an operation unviable.

·         It could be argued that these are local issues, however, the trade in NORM is international and therefore the problem is international.

·         In many jurisdictions, radiation control regulation is linked to nuclear regulation. For simple operations with NORM, being associated with nuclear activity may make the operation untenable.

·         Regulation (and subsequent constants) should only be applied commensurate with the risk.

ICRP provide clearer advice in order to ensure a “level playing field”.

Line Number

Quotation

Comment

Lines 44-47

Reference in the Abstract to there being no real prospect of a radiological emergency leading to deterministic effects, but the potential for significant environmental impacts (including of a radiological nature [assume referring to stochastic effects]) as a result of an accident.

For completeness, the text could include reference to the potential for significant routine occupational exposure in certain industries/situations [RE: stochastic effects; as alluded to in some of the entries in Table 2.1], if suitable control measures are not adopted.

For example; radiological protection in industries involving NORM is not just about exposures that result from accidents, which is what the Abstract text would seem to imply.

Line 132

The other primordial radionuclides are of much lower abundance.

The sentence is not correct. Rb-87 occurs in the continental crust with an abundance of about 20 – 30 ppm. But its radiological significance is much lower than that of the U-238 and Th-232 series

Line 138-140

For example, certain minerals (e.g. zirconium,  monazite),  including  some  that  are  commercially  exploited,  may contain potassium and/or thorium and/or uranium progeny at significant concentrations.

Zirconium and monazite do not contain potassium at significant concentrations. Add another example or omit potassium

Line 152-153

The discovery of radioactive scales from natural sources in British and American oil production facilities was first mentioned in the 1950’s (Schmidt, 2000)

The history of radioactivity in scales in oil production facilities is much longer. The document should describe the facts in a comprehensive way. (For example, NORM is mentioned in “1904 – John Cunningham McLennan. ‘On the radioactivity of mineral oils and natural gases’. Proceedings of the International Electrical Congress, Saint Louis, Canada, pp. 398–422”

Line 192 - 193

Exposures from natural sources are considered to be existing exposure situations.

This sentence is referred to ICRP 103 – and is not written there in this clear form. Unproven statements should not be the style of ICRP.

Lines 194-197

Industries involving NORM have been regulated variably with regard to radiological protection, because the radiological protection system has typically been introduced (or ‘is frequently introduced’) after the start of operation, and existing industrial hygiene controls already limit the potential for radiation exposure (e.g. control of airborne dust).

Such retrospective introduction of an RP system is not always the case. If the employer is suitably informed/has good awareness (possibly via the environmental regulator for other substances/activities) before the start of operations, sometimes control measures (including monitoring regimes) can be introduced at the start.

Lines 199-200

Exclusion and exemption of industries involving NORM and activities using numerical criteria may be useful but can lack the quantitative judgement that is also often necessary.

Not necessarily true. There are examples of criteria based upon quantitative radiological impact assessment which allow for NORM-specific exemption in some regulatory regimes.

Line 227

(13) Some mining facilities, however, have been established for the expressed purpose of extracting materials such as uranium and thorium from ore to be used for their radioactive, fissile or fertile properties. These industries are considered as planned exposure situations under the current system of radiological protection as outlined by the Commission in ICRP, 2302007 and are not the subject of this publication.

It is confusing if industries that have the highest activity concentrations and exposures are put under a special (normal) regime and all other industries / mining is considered as an existing situation. This generates confusion and is not helpful for the practice. [See above general comment on Planned versus Existing Exposure Situation].

Line 348-358

Table 2.1. Examples of dose assessments for workers (external and internal from dust, excluding exposure to radon)

It is not clear how the doses have been calculated. In particular, it is not clear whether the dose calculations include mitigation or protection measures (such as respiratory protection/face pieces to protect workers from dust) or if the doses refer to a situation in which no protection measures are applied.

Lines 328-329

Internal exposures from inhalation of NORM can be significant, especially where higher activity concentrations are present (e.g. above tens of Bq g-1).

In certain circumstances it is possible to receive ‘significant’ [i.e. several mSv/y] doses at much lower activity concentrations than tens of Bq/g.

Line 418-422

Existing   exposure situations are  exposure situations 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. Characterisation of exposures is a prerequisite for their control;

Here ICRP gives a significant new definition of existing exposure situations. In ICRP 103 (para 176) was written:

“Existing exposure situations are exposure situations that already exist when a decision on control has to be taken, including prolonged exposure situations after emergencies.”

There is no sufficient justification in the draft as to why the addition with regard to “intention to use the source for its radioactive properties” is necessary. It seems that this addition is completely arbitrary and academic.

Note that uranium is used in the nuclear industry not for its radioactive properties but for its fissile properties.

Line 430 onwards

[RE: the whole ‘Planned vs Existing, Dose Limitation vs Reference Level’ issue]

This would be confusing for a regulator. Even if the approach of Existing Exposure Situation with reference levels [which could vary across the different industries involving NORM] was to be adopted, they would still require a backstop in the form of a statutory dose limit for regulatory purposes.

Having a higher dose limit for one worker and a lower reference level for another (or different levels across different industries), could perhaps lead to confusion about health effects [“our radiation is less dangerous than your radiation, so we’re allowed more of it”!], and/or an opinion amongst one group of workers that they’re more valuable/protected (or, conversely, more expendable), than another group of workers. Simply continuing to optimise to ALARA, with a worker and public dose limit in the background, would seem to be a more sensible approach.

Line 454-456

Industries involving NORM are generally situations where multiple hazards and pollutants are present. The radiological risk may not be the dominant hazard, and consequently, there has often been no or only a limited radiological protection awareness.

It is not necessarily only about employers prioritising/concentrating on the dominant hazard (whilst being mindful of the radiological issues, although not addressing them). Frequently, and fundamentally, the issue can be one of a total lack of awareness (or acceptance) that the radiological hazard actually exists.

Line 1160-1163

Industries involving NORM are generally licenced,

although in most cases not for radiological purposes, and these industries are used to managing risks. ... experience shows that the system of radiological protection is very specific and perceived to be difficult to include in the management of other hazards.

The term “licensing” is very broad. The paragraph in its generality is obsolete or should be rephrased to be more specific. It is not true either that “experience shows that the system of radiological protection is difficult to include in the management of other hazards”. Rather to the contrary, experience shows that if other HSE risks are properly managed in an operation, radiation protection is usually taken care of very well.