Skyshine

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Schematic representation of the Skyshine effect (S: radiation source, SH: shielding, D: detector, red arrows: paths of ionizing particles ( neutrons , photons ), blue line: Skyshine intensity on the ground with maximum M)

As skyshine ( engl. Sky "heaven" and shine "lights") is that of a nuclear or nuclear medicine outbound investment ionizing radiation called that does not reach the vicinity of the plant directly, but from the atmosphere to the Earth's surface back reflected and scattered becomes. This effect occurs when the shielding around the radiation source is open at the top. In a broader sense, the radiation that is scattered back inside nuclear facilities, for example over the hall ceiling, is also referred to as a skyshine.

The intensity of the radiation measured on the ground initially increases with increasing distance from the shield up to a maximum and then decreases continuously. Depending on the type of radiation, the maximum occurs at different distances from the radiation source. In studies z. B. for X-rays from medical linear accelerators maxima measured at 13.6 m for 18  MeV and at 4.6 m for 6 MeV.

From 1967 to 1975 there was significant pollution from Skyshine on and outside the premises of the AVR Jülich test reactor , which had no upward radiation shielding.

In 2011 the effect received media attention in the context of the discussion about the Gorleben nuclear waste storage facility , after outside the facility, its shielding and the like. a. is designed as a protective wall, increased radiation values ​​were measured.

Individual evidence

  1. ↑ IS Lagutina, VP Mashkovich, AA Stroganov, AM Chernyaev: skyshine from photon radiation. In: Soviet Atomic Energy. 66, 1989, p. 118, doi : 10.1007 / BF01121800 .
  2. ^ A b Gossman, M., McGinley, P., Rising, M., Pahikkala, A .: Radiation skyshine from a 6 MeV medical accelerator. Journal of Applied Clinical Medical Physics, Vol. 11, No. May 3, 2010, accessed November 27, 2011 .
  3. ↑ Report No. 151 - Structural Shielding Design and Evaluation for Megavoltage X- and Gamma-Ray Radiotherapy Facilities (2005). National Council on Radiation Protection and Measurements , 2005, accessed November 27, 2011 .
  4. ↑ Responsibility in radiation protection when working in and with external companies. State Institute for Occupational Safety and Health NRW, May 1, 2001, accessed on November 27, 2011 .
  5. ↑ Andreas Langen: Give us the ball. (No longer available online.) Context: weekly newspaper, December 2011, archived from the original on May 11, 2012 ; Retrieved December 12, 2012 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.kontextwochenzeitung.de
  6. ^ "Skyshine" over the Castor camp. Stern , November 25, 2011, accessed November 27, 2011 .