Title: Countermeasures for dairy products in nuclear emergencies

Authors: Kari Sinkko, Michael Ammann, Eila Kostiainen, Anneli Salo, Kari Liskola, Raimo P. Hämäläinen and Jyri Mustajoki

Status: Radiation and Nuclear Safety Authority, STUK-A185, June 2001, pp. 68. (in Finnish)

Keywords: Nuclear emergency management, countermeasures on dairy products, multi-attribute risk analysis, decision support, rodos

This work was performed in order to plan countermeasures that, after an accidental release of radioactivity, could reduce the dose to the public due to the consumption of contaminated milk and milk products. The attention was focused on whether there are justified and optimised actions below the international recommended concentration levels in foodstuffs. The analysis was conducted as a case study, i.e., it was assumed that a hypothetical accident had happened in a nuclear power plant leading to a release of radionuclides which severely contaminated a wide area of Ostrobothnia, one of Finland's most important milk production areas. The dose averted by actions, the monetary costs and the feasibility of actions were assessed. It was also studied what information is needed by decision-makers and in which form this information should be presented. Finally, it was examined how planning of countermeasures could be enhanced by applying decision analysis in establishing actions strategies and valuing attributes considered in decision-making. Preparative meetings and a concluding workshop was arranged and all authorities involved in food-related emergency management were invited to jointly analyse different options.

According to the query made the participants considered the decision workshop and decision analysis very practicable in exercises. The exercise as a whole was also evaluated useful or very useful. The presented techniques in a real situation were considered applicable but not as useful as in exercises. Thus it can be deduced that the concluding workshop and decision analysis interviews augment well conventional emergency exercises.

Realistic dose assessments proved out to be very difficult. The software used was able to calculate the maximum radionuclide concentrations in foodstuffs processed from local raw materials. Radionuclide concentration in food or feedstuffs may, however, change quickly. Also, the production and processing of foodstuffs is a complex chanin of events during which the raw material and end products move from locality to another. To take all this into account realistically might be too demanding considering the available resources. Nevertheless, appropriate dose assessments models should be developed to meet the needs of the decision-making.

Large amount of milk is produced in the hypothetical fallout area. If fodder from pasture is replaced by uncontaminated fodder produced elsewhere over three million kilos of clean fodder a day is needed and several thousands of lorries to transport it. The organisation of transportation was seen feasible by most participants. Prohibiting the use of milk or changes in production create measurable waste disposal problems. The milk production rate is about two million kilos a day. Disposing milk into a sludge well and mulching it into fields together with other radioactive excretions was considered ethically questionable. For the present, there are no plans to treat milk, whey, process water, milk powder or cut grass as dump or burial waste or to dispose them in a final repository. Waste disposal has proven out to be a demanding task and we should be prepared for it beforehand.

The availability of fodder at the time of the hypothetic accident was perhaps the worst possible: the crop of the previous year was drying up and the new one was not yet harvestable. The extent and severity of the accident was also estimated to be extremely rare in reality. Based on the analysis it could be concluded that in a national nuclear accident justified and optimised countermeasures could very probably be implemented below internationally recommended concentration levels in foodstuffs. If the international intervention levels were exceeded the use of milk products on sale should be prohibited. According to the analysis the costs due to banning of use causes the most disadvantage.