Strahlungsmessungen an Transport- und Lagerbehaeltern zur Befoerderung von hochaktiven Glaskokillen aus der Wiederaufarbeitung und von bestrahlten Brennelementen

An den Behaeltern TS 28 V, CASTOR HAW-20/28-CG, beide mit HAW-Kokillen aus der Wiederaufarbeitung bestrahlter Brennelemente bei der COGEMA beladen, sowie am Behaelter CASTOR V/19, beladen mit bestrahlten Brennelementen aus dem Gemeinschaftskraftwerk GKN 2, konnten umfangreiche Messungen zur Ermittlung des Strahlungsfeldes in der Umgebung beladener Transport- und Lagerbehaelter durchgefuehrt werden. Die dabei ermittelten Werte der Gamma- und Neutronendosisleistung stehen im Mittelpunkt dieses Berichts. Die entsprechenden Messprotokolle sind in Anlage 2 und die Dosisleistungen, ggf. nach Beruecksichtigung individueller Kalibrierfaktoren, in den Tabellen 1 bis 5 zusammengefasst. An ausgewaehlten Messpunkten wurden Vergleichsmessungen von kommerziellen Ortsdosimetern fuer die Neutronenstrahlung mit einem Mehrkugelspektrometer als Referenzgeraet durchgefuehrt, deren Ergebnisse in den Tabellen 6 bis 9 angegeben sind. Fuer eine weiterfuehrende Auswertung, z.B. Nachrechnung mit verschiedenen Programmen zur Abschirmung, sind die Inventardaten in Anlage 1 aufgenommen worden. Abschliessend ist festzustellen, dass alle Messwerte, auch diejenigen an Orten mit erhoehter Dosisleistung weder die Werte in den Technischen Annahmebedingungen des TBL Gorleben noch die im Verkehrsrecht festgeschriebenen Grenzwerte uebersteigen. (orig.)The measuring activities reported cover a wide range of measuring tasks for characterisation of radiation fields at and in the proximity of loaded storage and transport casks. The cask types examined are: TS 28 V and Castor HAW-20/28-CG, both carrying HAW flasks with high-level waste from the reprocessing of spent fuel assemblies at COGEMA; and the Castor container V/19, carrying spent fuel elements from the GKN-2 reactor. The report focuses on the gamma and neutron dose rates measured, the data are shown in tabulated form, and the measuring protocols are given in Annex 2. In addition, intercomparison measurements were carried out for comparative assessment of a number of commercial ambient dosemeters for neutron radiation, using a multisphere spectrometer as a reference standard. The relevant results are listed in Tables 6-9. (orig./CB)SIGLEAvailable from TIB Hannover: RO 9716(32/00) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Highly demanding resistive vibration exercise program is tolerated during 56 days of strict bed-rest

Several studies have tried to find countermeasures against musculoskeletal de-conditioning during bed-rest, but none of them yielded decisive results. We hypothesised that resistive vibration exercise (RVE) might be a suitable training modality. We have therefore carried out a bed-rest study to evaluate its feasibility and efficacy during 56 days of bed-rest. Twenty healthy male volunteers aged 24 to 43 years were recruited and, after medical check-ups, randomised to a non-exercising control (Ctrl) group or a group that performed RVE 11 times per week. Strict bed-rest was controlled by video surveillance. The diet was controlled. RVE was performed in supine position, with a static force component of about twice the body weight and a smaller dynamic force component. RVE comprised four different units (squats, heel raises, toe raises, kicks), each of which lasted 60 - 100 seconds. Pre and post exercise levels of lactate were measured once weekly. Body weight was measured daily on a bed scale. Pain questionnaires were obtained in regular intervals during and after the bed-rest. Vibration frequency was set to 19 Hz at the beginning and progressed to 25.9 Hz (SD 1.9) at the end of the study, suggesting that the dynamic force component increased by 90 %. The maximum sustainable exercise time for squat exercise increased from 86 s (SD 21) on day 11 of the BR to 176 s (SD 73) on day 53 (p = 0.006). On the same days, post-exercise lactate levels increased from 6.9 mmol/l (SD2.3) to 9.2 mmol/l (SD 3.5, p = 0.01). On average, body weight was unchanged in both groups during bed-rest, but single individuals in both groups depicted significant weight changes ranging from - 10 % to + 10 % (p < 0.001). Lower limb pain was more frequent during bed-rest in the RVE subjects than in Ctrl (p = 0.035). During early recovery, subjects of both groups suffered from muscle pain to a comparable extent, but foot pain was more common in Ctrl than in RVE (p = 0.013 for plantar pain, p = 0.074 for dorsal foot pain). Our results indicate that RVE is feasible twice daily during bed-rest in young healthy males, provided that one afternoon and one entire day per week are free. Exercise progression, mainly by progression of vibration frequency, yielded increases in maximum sustainable exercise time and blood lactate. In conclusion, RVE as performed in this study, appears to be safe