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Belgian regulations with respect to cosmic rays exposure and results of the dose assessment. Information session on aircrew exposure to cosmic radiation – Brussels – 20/01/2009 S. Pepin (Federal Agency for Nuclear Control). What is cosmic radiation ?.
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Belgian regulations with respect to cosmic rays exposure and results of the dose assessment Information session on aircrew exposure to cosmic radiation – Brussels – 20/01/2009 S. Pepin (Federal Agency for Nuclear Control)
What is cosmic radiation ? Primary cosmic radiation: high energetic particles from space (mainly hydrogen and helium nuclei) Galactic component (main component): e.g. supernova explosions,… Solary component (11-years cycle, may be significant in case of solar disturbance event / solar flare – e.g. 1956)
What is cosmic radiation ? • Secondary cosmic radiation - interaction of • primary cosmic radiation with earth’s atmosphere • => secondary particles • 2 main factors affecting the flux of • cosmic radiation: • Altitude (absorption by the atmosphere) • Latitude (protection due to • earth’s magnetic field decreases • with latitude – highest dose near • the poles)
European regulatory framework (1) European Directive 96/29/EURATOM If dose > 1 mSv/y, airlines shall: • assess the exposure of the crew concerned • take into account exposure when organizing working schedules with a view to reducing the doses of highly exposed aircrew. • inform the concerned workers about the health risks their work involves. • take care of limitation of doses during pregnancy (< 1 mSv/y + ALARA - “As Low As Reasonably Achievable”).
European regulatory framework (2) Radiation protection 88: “Recommendations for the implementation of Title VII of the European Basic Safety Standards Directive concerning significant increase in exposure due to natural radiation sources” • “Highly exposed aircrew” : > 6 mSv/y • 1 – 6 mSv/y: individual estimates of the dose • > 6 mSv/y: appropriate medical surveillance
Belgian regulatory framework (1) Euratom directive => Royal Decree of 07/20/2001 (article 4 and 9) Art. 9 : For aircrew with dose possibly > 1mSv/y: • assess individual doses • take into account dose assessments in the working schedules (at least < 6 mSv/y) • inform the concerned workers (+ company medical officer) • limitation of doses during pregnancy (As Low As Reasonably Achievable – in any case < 1 mSv/y) NB: till now, no specific medical follow-up if dose < 6 mSv/y
Belgian regulatory framework (2) • Guidelines from the FANC (http://www.fanc.be => folder “Natural radiation”) • “Exemption criteria” (e.g. altitude < 6000m + flying time < 700 h) • If no exemption software-based evaluation • Yearly dose evaluation if dose > 1 mSv/y • Monthly if dose > 6 mSv/y
Results of dose assessment 9commercial airlines investigated. Last december, information campaign for non-commercial airlines Commercial airlines: • 3 “exempted” (“air taxi” companies) • 6 with doses > 1 mSv/y Software used: CARI, IASON-FREE, PCAIRE, GlobaLog Dose assessment for 1429 persons 907 people > 1 mSv/y (average dose ~ 2 mSv/y) Nobody > 6 mSv/y Maximal dose = 4 mSv/y
Dose distribution(1) Company A (IASON), Company B (PCAIRE) – charters flight Distribution pattern depends on specific airline (flight profile,…)
Dose distribution (2) Global dose distribution for all companies Significant # people in the upper range of the distribution
Conclusions • Majority of aircrew members > 1 mSv/y • Dose distribution pattern depends on specific airline Open issues : • Parameters affecting the dose distribution ? • Which optimisation measures ? • Necessity and type of medical follow-up for dose 1 – 6 mSv/y ?