BEGIN:VCALENDAR VERSION:2.0 PRODID:www.dresden-science-calendar.de METHOD:PUBLISH CALSCALE:GREGORIAN X-MICROSOFT-CALSCALE:GREGORIAN X-WR-TIMEZONE:Europe/Berlin BEGIN:VTIMEZONE TZID:Europe/Berlin X-LIC-LOCATION:Europe/Berlin BEGIN:DAYLIGHT TZNAME:CEST TZOFFSETFROM:+0100 TZOFFSETTO:+0200 DTSTART:19810329T030000 RRULE:FREQ=YEARLY;INTERVAL=1;BYMONTH=3;BYDAY=-1SU END:DAYLIGHT BEGIN:STANDARD TZNAME:CET TZOFFSETFROM:+0200 TZOFFSETTO:+0100 DTSTART:19961027T030000 RRULE:FREQ=YEARLY;INTERVAL=1;BYMONTH=10;BYDAY=-1SU END:STANDARD END:VTIMEZONE BEGIN:VEVENT UID:DSC-22503 DTSTART;TZID=Europe/Berlin:20251211T150000 SEQUENCE:1765435016 TRANSP:OPAQUE DTEND;TZID=Europe/Berlin:20251211T160000 URL:https://dresden-science-calendar.de/calendar/en/detail/22503 LOCATION:TUD Andreas-Schubert-Bau\, Zellescher Weg 1901069 Dresden SUMMARY:Seminar: In situ activity determination in decommissioned nuclear f acilities CLASS:PUBLIC DESCRIPTION:Speaker: \nInstitute of Speaker: \nTopics:\nPhysik\, Willkommen \n Location:\n Name: TUD Andreas-Schubert-Bau (E19)\n Street: Zellescher Weg 19\n City: 01069 Dresden\n Phone: \n Fax: \nDescription:

If con crete structures in nuclear power plants are activated or contamination ar e
introduced\, is a crucial question in nuclear dismantling. For answe ring this question\,
conventional drill cores are taken and examined a fterwards in a laboratory analysis.
A fiber optic radiation sensor (FO RS)\, which is based on a GAGG scintillation
crystal coupled to a poly mer optical fiber and a photomultiplier tube\, was developed
in this t hesis as a more efficient alternative sampling method. It is designed for< br> measurements in thin on-site boreholes in nuclear power plants. A spec ific activity
of 0.1 Bq g−1 of the nuclide 137Cs was statistically s ignificantly detected in laboratory
experiments in a concrete phantom within a measurement time of 4 min. Therefore\,
analyses were applied based on the “Guide to the Expression of Uncertainty in
Measurement ” (GUM) and the Kolmogorov-Smirnov test.
A second method of examinat ion enables not only the detection of a contamination
but also the qua ntitative determination of its specific activity. This was possible to a lower limit of 0.1 Bq g−1 for the nuclide 137Cs. For this reason\, an analysis parameter
was determined based on the two-dimensional Kolmog orov-Smirnov test\, which is
proportional to the specific activity. Th erefore\, the measurment to be investigated is
compared to combination s of measurements with different specific activities.
In two field tes ts in the nuclear power plant Unterweser\, which is in the process
of dismantling\, the activity of localized contaminations and acitived struct ures was
determined. The activity per area of an activated metal shiel d was estimated in
the walls of the reactor and spent fuel pool. In th e investigation of the calotte\, the
determination of a specific activ ity of 60Co was possible. The value of it exceeded
0.1 Bq g−1 only i n a very localized area. If the spatial expansion is estimated correctly\,
the results of the FORS analyses are in good accordance with drill co re analyses at the
same sample places.

DTSTAMP:20260614T224729Z CREATED:20251203T063739Z LAST-MODIFIED:20251211T063656Z END:VEVENT END:VCALENDAR