information

URN: urn:nbn:de:101:1-201605303033
URN: urn:nbn:de:101:1-201605303077

Abstract

Nuclide-specific operational intervention levels have so far been missing for accident scenarios that may involve releases of alpha and beta emitters from sources that are normally sealed and shielded. Such scenarios – particularly those concerning urban environments – could potentially affect a large number of people and the contamination may seriously restrict the continued use of the area, e.g. as a place of work or residence. Accordingly, for any decisions about protective measures for the population to be made, it is vital to provide operational intervention levels which serve as a basis for the verification of the compliance with intervention levels.

Incidents leading to alpha or beta contaminations give rise to a number of specific problems:

• The dose-rate measuring devices generally used by the police and the fire brigades are unsuitable to detect this type of existing contaminations,
• nuclide-specific measurements involving, e.g. alpha spectrometry are time-consuming,
• when it comes to beta radiation, conventional radiation protection monitoring of emergency workers using dosimeters cannot be ensured due to the general lack of beta-sensitive dosimeters.

For environmental contamination with alpha and beta emitters, the German Commission on Radiological Protection (SSK) therefore recommends an effective dose of 10 mSv as an intervention level for initiating protective measures for the public. The SSK deduces intervention levels for ground contamination with relevant alpha and beta emitters and specifies intervention levels for the skin dose whose exceedance should trigger the decontamination of persons. Beyond this, the SSK outlines a protection strategy aimed at the limitation of the radiation exposure of the public and the emergency workers.