This title appears in the Scientific Report : 2014 

Internal Dosimetry after Inhalation of UF6 - A Case Study
Froning, Martina (Corresponding Author)
Hill, Peter
Betrieblicher Strahlenschutz; S-B
VI International Conference 'Semipalatinsk Test Site: Radiation Legacy and Development Perspectives', Kurchatow (Kazakhstan), 2014-09-24 - 2014-09-26
ohne Topic
INTERNAL DOSIMETRY AFTER INHALATION OF UF6 - A CASE STUDYM. Froning, P. HillForschungszentrum Jülich GmbH, S-BI, 52425 Jülich, GermanyIntroduction: During a release of UF6 in a nuclear installation in Germany an employee was contaminated externally and internally. Inhaled uranium is in the chemical form UF6 very well soluble (class F) and can be easily taken up into blood and the lymphatic system.Monitoring: Extensive incorporation monitoring of urine and feces, as well as measurements of blood, nose-blow- and sputum samples on 234U, 235U and 238U followed immediately after the incident. The total monitoring period covered about 4 weeks.To enhance the excretion rate a solution of 8.4 percent sodium bicarbonate was administrated in the first few days as a means of medical precaution. During this time urine and feces samples taken were essentially of low volume (e.g. spot samples). Excretion rates have been analyzed by means of ICP-MS and α-spectrometry. The latter was used for quality assurance of the results. The laboratory is flexibly accredited (DIN ISO/IEC 17025:2005) for these test methods.Dose assessment: Internal dose has been assessed following the rules of the official German guideline on incorporation monitoring. This guideline must be used for legal purposes. An effective Dose of E = 0.8 mSv and a lung dose of HLung = 14.5 mSv have been calculated. Additionally expert software has been used for internal dose calculation. Since excretion rates in the beginning of the monitoring period were enhanced, later samples were especially helpful in realistically determing internal dose.Final remarks: The biocinetic uranium model of ICRP78[1] seems not to be adequate to describe excretion within the first hours after intake. The data obtained from spot samples during the first day indicate an underestimation of exretion rates by several orders of magnitude. The study shows that extended follow-up monitoring can help to clarify the dose relevant medium-term systemic uptake after an incident.A recent communication of the case study in English (extended abstract) can be found in ref. [2].[1] ICRP Publication 78; Individual Monitoring for Internal Exposure of Workers; Annals of the ICRP Vol. 27 No. 3/4, 1997[2] M.Froning, H.Doerffel and P.Hill; Internal Dosimetry after Inhalation of UF6 - A Case Study; Fourth European IRPA Congress ‘Radiation Protection Culture – A global challenge, June 23-27,2014, Geneva, Switzerland; Book of abstracts, Paper PS5-04/6; (last accessed: July, 28th 2014)