Humorous confessions

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1.1. Awakening period (1975–1985)

The awakening started in 1975, when preliminary results were reported about the elevated

226Ra activity concentration in coal and flyash [1]. These preliminary results triggered a number of additional investigations:

(a) A more thorough study of elevated levels of uranium in flyash in comparison with the original coal [2];

(b) A survey initiated by the Dutch regulator with its main aim being to “collect data to be able to judge on the radiation dose caused by construction materials” [3];

(c) A study on “Radioecology of and radiation dose from Dutch waste gypsum released into the environment” [4].

This awakening period can be best described as the period that health physicists, regulatory bodies, etc. became aware of NORM and its possible contribution to the collective and individual dose. Looking at the regulations at that time, it can be concluded that most regulations were developed for the nuclear industry and did not take into account radiation effects caused by natural materials.

1.2. Basic document on radon (1985–1991)

The regulatory body initiated a study to determine (i) the radiological risks for man and the environment with special attention to indoor conditions in homes, (ii) the technical possibilities for reducing these risks, and (iii) potential policy scenarios in relation to radon [5].

Based on this study it was advised that the focus should be on measures in newly built houses as this would lead in time to a substantial reduction of the individual risk. In 1988 a study on the radiological properties of consumer goods was finalized. It was estimated that consumer goods were responsible for 90% of the collective dose [6].

In that period much effort had also been dedicated to improved sampling and gamma spectroscopic techniques for NORM [7]. The reduction and control of the risk to the public due to radon were addressed in more detail by the regulatory body in a national policy document.

At that time, the regulatory body was in principle ready to formulate a policy and/or law to regulate exposure of the public to NORM as far as dwellings (and, to some extent, industry) were concerned. However, the consequences of such a policy and/or law on the industry were still not completely understood. Therefore the Minister decided to apply the ‘stand still principle’. This was the start of more than a decade of research and discussions between the stakeholders. In this period also, a first outline of NORM related problems in industry became apparent.

1.3. European Council Directive 96/29/Euratom (1991–1996)

The milestone in this third period was the development of European Council Directive 96/29/Euratom for the health protection of the general public against the danger of ionizing radiation [8]. This Directive includes a section dealing with the exposure of the public and workers to natural sources. It was clear that the choice of values of clearance and exemption levels for naturally occurring radionuclides could have a large impact on the industry. Therefore national and international studies were initiated by the regulatory body and by private companies to assess the problem [9], as well as to determine the radiological risk associated with NORM and the consequences of possible clearance and exemption levels for different industries [12–15]. The effect of these studies was that other countries also became aware of

103 the problems that could be faced by having criteria for NORM that were too strict. It is believed that the active approach by the Dutch regulatory bodies, both at a national and international level, positively influenced the industry in establishing exemption and clearance levels for NORM in Directive 96/29/Euratom.

1.4. Implementation of Directive 96/29/Euratom through national legislation (1996–2002)

During preparation for the implementation of Directive 96/29/Euratom through national legislation, the government and the industry initiated supporting studies [16–19]. As one of the final steps in this preparation, the government initiated an evaluation of the basis for the proposed clearance levels to be applied in the new national legislation [20]. It should be noted that during this period a close and fruitful cooperation was established between regulatory bodies, industry and other stakeholders. In 2002, the new Dutch legislation based on Directive 96/29/Euratom entered into force.

1.5. Implementation of national legislation into practice (2002–2011)

In 2002, the results of a second study entitled Radioactivity in Dutch Consumer Articles were published [21]. One of the conclusions of this study was that the annual collective dose had dropped from 130 manSv in 1988 to 4.6 manSv in 2002. This decrease was mainly caused by the replacement of NORM containing materials by non-radioactive materials. However, new production and construction methods, as well as ventilation techniques aimed at energy efficiency, caused an increase in the average radon concentration in homes. Levels increased from an average of 20 Bq/m³ in 1970 to an average of 30 Bq/m³ in 1990 [22].²

Specific legislation for NORM in the Netherlands started in 2004 with an ordinance concerning natural activity of sources of ionizing radiation (the NABIS Ordinance) [23]. This was revised in 2008. As a result, the average dose due to radon slowly decreased at an estimated rate of 1.5 Bq/m³ per decade [24].

Nowadays, different treatment routes are available for different kinds of NORM residues, e.g. use, landfill disposal, recycling by melting (metals) and, as a last option, interim storage [25]. The appropriate route is determined by legislation, infrastructure and economics. The use of NORM residues is explicitly mentioned in the NABIS Ordinance, as is the possibility of disposing hazardous NORM waste in a specified waste repository (a landfill site).

By restricting the use of NORM in consumer products, collective doses are decreasing and some of the minerals processing industries are starting to take into account the radiological properties of their process materials along with other parameters. It can be concluded, therefore, that the regulatory policy is starting to be successful.

1.6. Evaluation and the future (2011 onwards)

A new, revised Directive on radiation protection (Directive 2013/59/Euratom) was adopted by the Council of the European Union in 2013. Its implementation in the Netherlands will necessitate considerable changes to the NABIS Ordinance. It is expected that studies will have to be carried out to investigate the consequences of the application of NORM by-products (in the construction and maintenance phases) as well as the consequences of NORM releases during the demolition of structures and the possible (secondary) use of materials.

2 Based on improved radon measurements, the author of Ref. [22] reported also that the average radon concentrations reported in the past might have been influenced by the exhalation of thoron. The specifics of thoron detection and assessments of its influences are beyond the scope of this paper.

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The Dutch legislation for NORM has been compared with that in neighbouring countries [26]. The findings are that the Dutch legislation is relatively strict and, as a consequence, the administrative costs are relatively high. Some existing rules are rather complex and unclear and give rise to problems with the enforcement of the legislation. This outcome has motivated the start of discussions with stakeholders about relaxation of legislation. The regulatory body has pointed out that there is room for improvement in national legislation in terms of: (i) clarification of existing rules and regulations, (ii) a multi-stage risk assessment approach (iii) relaxation of releases into soil as a result of gas production. The regulatory body has also expressed a need to act upon these findings at an international level, for instance by proposing modifications to the European Directive [26].

1.7. Discussion

The above summary describes ‘the process from NORM awakening to maturity in the Netherlands’ based on facts and milestones of this process reported in the literature. It is evident that, during this process (already covering a time span of almost 50 years), a large number of organizations and people have been participating. It should be mentioned that there have been no serious drawbacks during this process and even the current stakeholders in the process are still cooperative and have confidence in each other and in the ongoing process.

2. HISTORICAL, EXISTING AND FUTURE AMOUNTS OF REGULATED NORM