La citologia da aspirazione con ago sottile del nodulo tiroideo: revisione critica di due anni di attività del servizio autonomo di endocrinologia

L’esame citologico da ago aspirato tiroideo (FNAB, Fine Needle Aspiration Biopsy) è complemento fondamentale nella diagnostica del nodulo “freddo” tiroideo. 500 pazienti consecutivi con nodulo/i non captante/i di età compresa tra i 9 e gli 82 anni, rapporto F: M 9: 1, sono stati sottoposti a FNAB negli ultimi due anni presso il Servizio Autonomo di Endocrinologia. Nel 90¾ (450/500) dei casi l’esame citologico ha permesso di porre diagnosi di lesione benigna della tiroide; solo nel 10% dei casi il risultato era sospetto (35/500, 7%) o conclusivo (15/500, 3%) per lesione maligna. Mentre l’esame citologico è risultato altamente specifico nella diagnostica delle lesioni maligne papillari (conferma istologica 72%), nelle lesioni follicolari l’esame citologico sovrastimava rispetto alla istologia definitiva (con ferma istologica 20%)

First wall material issues and related activities at JET

To close the JET tritium material balance a comprehensive programme to determine the tritium inventory in a selected poloidal set of JET tiles was initiated. First results strongly suggest that a significant fraction of the tritium remaining in the machine is immobilised in flakes accumulated in the sub-divertor region. Measurements performed with tiles and flakes retrieved from JET after the DTE1 campaign revealed a chronic tritium release at room temperature, possibly caused by, a radiation-induced mechanism. Deposited films of the order of 5 mum thick are found at the vertical surfaces of the inner divertor. Recent analysis of the distribution of beryllium across the divertor shows factors of approximate to 10 higher beryllium concentrations (relative to carbon) in these deposits than found in the main camber walls. Very little beryllium is found on the outer divertor. Also no beryllium is detectable in the thick deposits accumulated in the shadowed regions of the inner divertor. These results suggest that in ITER migration of beryllium from the main chamber to the divertor surfaces could substantially reduce the chemical erosion and consequently the retention of tritium. (C) 2002 Elsevier Science B.V. All rights reserved

DESIGN OF Pb-17Li/WATER BLANKETS FOR A DEMONSTRATION FUSION REACTOR

Two types of Pb-17Li/water blankets developed for a DEMO tokamak reactor are presented. The first one, consisting of circular breeder modules, is intended for the central zones around the plasma. The second one, consisting of layers of breeder and cooling tubes, is suited for zones behind the divertor plates. A simplified calculation of tritium breeding in the European DEMO configuration, based on 1D calculations, indicates that tritium self-sufficiency can be achieved. Confirmation of these results by 3D analysis looks mandator

Modelling of the thermal mechanical behaviour of a single size beryllium pebble bed

The Helium Cooled Pebble Bed (HCPB) Blanket for fusion power reactors and the ITER breeding blanket are based on the use of pebble beds of lithium ceramics as breeder and beryllium as neutron multiplier. Experimental activities were performed at Forschungszentrum Karlsruhe concerning the measurement of pebble bed heat transfer parameters. At the Department of Nuclear Engineering of the University of Palermo, the experimental results have been reproduced by means of the ABAQUS finite element code. Moreover, a thermal-mechanical theoretical model has been developed for single size beryllium pebble beds. In the paper the results from the numerical and theoretical analyses and the comparison with experimental data are presented and critically discussed