An evaluation of the implementation of radiation protection measures for aircrew in EU Member States has recently been performed in a study sponsored by the European Commission. A comprehensive database has been gathered using questionnaires for civil aviation authorities, aircraft operators and radiation protection authorities in each country. The study has revealed the following results: all countries within the scope of this study where aircrew might receive annual doses >1 mSv have implemented appropriate legislation. The treatment of limits or constraints (action levels) for annual doses of 1, 6, 20 mSv could be an area where clear guidance by the European Commission might be needed. The way in which doses are determined might also be treated in a more harmonized way in the EU, including the transfer of dose data of freelancers or crew members working for other airlines. The establishment of the European Aviation Safety Agency leads to a gradual shift in responsibilities from the national civil aviation authorities towards this centralised European agency. Currently, however, tracking of doses for aircrew still lies with national bodies.

Results of purposeful groundwater monitoring and modelling studies are presented, which were carried out in order to better understand groundwater flow patterns from the "Vector" site for near-surface radioactive waste disposal and storage in the Chornobyl exclusion zone towards river network. Both data of observations at local-scale monitoring well network at "Vector" site carried out in 2015 -2016 and modelling analyses using the regional groundwater flow model of Chornobyl exclusion zone suggest that the groundwater discharge contour for water originating from "Vector" site is Sakhan River, which is the tributary to Pripyat River. The respective groundwater travel time is estimated at 210 -340 years. The travel times in subsurface for 90 Sr, 137 Cs, and transuranium radionuclides (Pu isotopes, 241 Am) are estimated respectively at thousands, tenths of thousands, hundreds of thousandsmillion of years. These results, as well as presented data of analyses of lithological properties of the geological deposits of the unsaturated zone at "Vector" site, provide evidence for good protection of surface water resources from radioactivity sources (e.g., radioactive wastes) to be disposed in the near-surface facilities at "Vector" site.

The new Radiation Protection Ordinance (RPO) in Germany which transforms the EURATOM Basic Safety Standards into national legislation contains detailed regulations on clearance. For each of the following clearance options, a separate set of clearance levels (CL) exists: unconditional clearance, clearance of building rubble (> 1000 Mg/a), clearance of buildings for demolition and for reuse, clearance of nuclear sites, and clearance for disposal or incineration. This paper outlines the basis for the derivation of these sets of CL which are all based on generic radiological scenarios taking into account all relevant aspects of the materials. The underlying dose criterion is 10 μSv/a individual dose and 1 man·Sv/a collective dose. When deriving sets of CL in Germany care has been taken to be compatible with recommendations of the European Union and the IAEA. It is a common experience that sets of CL which are intended for the same purpose (e.g. general, unconditional clearance) may vary between studies and therefore between countries. This follows directly from differences e.g. in material quantities, boundary conditions, waste management options etc. which may be country specific. German CL are, however, in full agreement with all recommendations issued by the European Commission.

No abstract

The nuclear power plant Wu¨rgassen in Germany entered into decommissioning in 1995. The project has currently advanced to the clearance of the buildings. Clearance of buildings has commenced in 2007 with establishing the clearance procedure in pilot rooms. It has entered the “productive” phase in 2010 and will last until about 2014. In 2007, Brenk Systemplanung has been commissioned by E.ON / NPP Wu¨rgassen to perform clearance of the pilot rooms in the turbine building. It has been one of the goals of this work to establish an innovative clearance procedure which would not rely on 100% surface measurements but which should be based on the use of in situ gamma spectrometry and the application of approaches to minimise the number of clearance measurements. In 2010 and 2011 Brenk Systemplanung has been commissioned by E.ON / NPP Wu¨rgassen to perform clearance of rooms with partly considerably higher contamination levels in other buildings. Central points of the concept for clearance of buildings which is presented in this paper were the establishment of averaging areas of up to 10 m2, which is an ideal size for the use of in situ gamma spectrometry, and the application of statistical methods, which allow an efficient performance of the clearance measurements. As a first step the measurement instrumentation necessary for the performance of clearance measurements had to be qualified. The innovative concept was first tested and implemented in the pilot rooms and has now been used also in various other parts of the NPP Wu¨rgassen. The procedure which has been established by Brenk Systemplanung for NPP Wu¨rgassen allows rapid measurements making best use of the averaging area and measurement area of collimated in situ gamma spectrometry and minimising the number of single measurements in comparison to other clearance procedures for nuclear installations of similar size. The paper highlights the relevant approaches and the conceptual differences and innovations.