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Nucleonics Week
Vol. 43 No. 17 April 25, 2002

U.K. WANTS SINGLE DOSE STANDARD FOR NUCLEAR, OTHER INDUSTRIES

U.K. decommissioning experts are registering increasing concern about aregulatory "double standard" developing throughout much of Europe that allows up to around 30 times higher individual dose rates from radioactive material released from non-nuclear industries as from the nuclear industry.

Norway and Holland appear to be the only countries until now striving to achieve equal treatment across the board. Norway uses an individual dose constraint of 10 microSieverts/year prescribed for the nuclear industry to also cover the exemption of radium (Ra)-226, Ra-228, and PB-210 (lead) recovered from oil and gas.

U.K. speakers and delegates at conferences and seminars over the past nine months have stressed the "glaring inconsistencies" in the regulatory treatment of exactly the same nuclide. "What is the scientific basis," asked Stan Gordelier, director of U.K. Atomic Energy Authority's (UKAEA) southern division at a decommissioning meeting in London last month.

Siempelkamp in Germany, for instance, melts radioactive scrap from the nuclear and oil and gas industries but has to meet a "nuclear" dose criterion much more stringent than the 1 milliSievert (mSv) maximum dose stipulated for the oil and gas side.

Roger Bond, an expert in the field, who was formerly with AEA Technology and is now running consulting company Normtec, described exemption and clearance levels in the U.K. as "a real problem”. We have a large number of statutory instruments with different levels of exemption," he told a London Waste Conference April 22. Bond suggested efforts be made to provide consistency in the advice from regulators.

The U.K. industry sees the costs involved in such double standards as particularly daunting as the country gears up to tackle its massive nuclear cleanup program. Nuclear decommissioning activity produces large amounts of relatively low-activity waste. Waste management in decommissioning programs typically accounts for between 40% to 60% of total project costs, according to experts in the field.

This week in London, Shankar Menon, the program coordinator for the OECD/NEA cooperative program on decommissioning, noted that both the European Commission (EC) and the IAEA appeared to be proposing disparate standards in draft regulations by suggesting a 10 microSieverts/year individual dose criterion for release of material from the nuclear industry and 300 microSieverts/year from the non-nuclear industries.

In doing this, a message is being sent to the public that nuclear radioactivity "is up to 30 times as dangerous" as radiologically similar material arising in non-nuclear industries, Menon told IBC's "Natural Radiation and NORM" conference April 22 and 23. Yet, "the U.S. Academy of Sciences has stated that there is no plausible rationale for any difference in risks from naturally occurring or any other radionuclides," he stressed.

It is only in the last decade that the international community has become aware of the prevalence of Tenorm (technologically enhanced naturally occurring radioactive material), he said. Tenorm is formed by the artificial concentration of radioactivity in products and byproducts in such industries as coal, fertilizer, oil, gas, and mining. "This Tenorm is just as artificial as the artificial nuclides produced in a nuclear reactor," he said.

The candidate quantities of Tenorm for release are more than three orders of magnitude larger than those from the nuclear industry, he said. Current regulations in many countries severely restrict the concentration and quantities of long-lived nuclides at near-surface repositories. The major radionuclide in Tenorm, Ra 226, has a half-life of 1,600 years. The huge quantities of Tenorm arisings may require them to be disposed in deep geological repositories if treated in the same manner as similar material from the nuclear industry, "with the consequent costs," he said.

"The same nuclide, at the same concentration," can either be sent to deep disposal or released for use in road repair, depending on where it is coming from, according to the current proposed double standards, he said.

The largest Tenorm waste stream is coal ash, with 280 million tons arising globally every year, according to Unscear. "What are the resulting individual doses to the public" of utilized coal ash, Menon asked conference delegates. "It is not known to us whether the EC has made any studies relating to the subject."

The dominating nuclides in scrap from the nuclear industry are Co-60 (cobalt), with a half-life of 5.4 years, and Cs- 137 (Cesium), with a half-life of 30 years, he said.

Application of the 300 microSievert/year dose limit for Tenorm results in a rounded general clearance level for Ra- 226 of 0.5 Becquerels/gram (Bq/g), compared with 0.01 Bq/g for "nuclear" materials, said Menon.

He also underscored the implications of the discrepancies in standards for the competitiveness of the deregulated market. Competition between nuclear and oil and coal could not help but be affected, with nuclear suffering from the more stringent regulatory criteria, he pointed out.

Menon called for the Tenorm dose criterion proposed in draft EC Radiation Protection guideline 122 to be applied equally to material from the nuclear industry. "It is time to do away with inconsistencies and have one unique dose criterion for all types of exposure to ionizing radiation, regardless of its source," he said.

Jan van der Steen of NRG, the Dutch nuclear research & consulting group, told the same conference that the inconsistency over regulating Ra-226 "is exactly the reason why we chose in the Netherlands to go for only the one figure."

Menon described current progress toward some kind of international regulation as "fluid and rather confused."

The 300 microSieverts/year criterion, he said, is two to three orders of magnitude lower than the doses absorbed for generations by tens of thousands of people living in high background dose areas of the world such as Ramsar in Iran, where the mean dose is 10.2 mSv/year and the maximum dose is 260 mSv/year; Guarapari, Brazil (5.5 and 35); Kerala, India (3.8 and 35); and Yangjiang, China (3.5 and 5.4), he said.

Yet preliminary biological studies indicated the inhabitants of such areas had not shown any differences in cancer mortality, life expectancy, chromosome aberrations, or immune function, compared to those living in normal background areas. He suggested further detailed studies be done of these groups.

Geoffrey Webb, an international radiation safety consultant and president of the International Radiation Protection Association, noted that studies of these high-dose groups had "been in the minds of Unscear for 20 years at least" but that though some studies had been done, Unscear (UN Scientific Committee on the Effects of Atomic Radiation) and other bodies in the international arena had generally not given a very high weight to the statistical results. This was because of a number of difficulties in studying such groups, including the inherent problems involved in the small size of the populations, the diagnosis of disease in the countries involved and the difficulty of coming up with a good control group.

In a separate interview with Nucleonics Week, Menon said, "The radiation protection establishment seems to be in a quandary about how to treat this enormous quantity of Tenorm when they havesuch stringent regulations for the same kind of radioactivity for a muchsmaller amount of arisings from the nuclear industry."

—Pearl Marshall, London

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