poster - Università di Pisa
Transcript
poster - Università di Pisa
TAWARA_RTM – The Detection System for Real Time Monitoring SCINTILLATORS FOR HIGH TEMPERATURE PLASMA DIAGNOSTICS of Radioactive Contamination in Water Processed at Water Treatment Facilities L. Swiderski, A. Gojska, M. Grodzicka, S. Korolczuk, S. Mianowski, M. Moszynski, J. Rzadkiewicz, P. Sibczynski, M. Lunardon1, D. Badocco2, T. Batsch3, E. Bodewits4, R. Brugera1, P. Carconi5, D. Cester1, P. De Felice5, M. Donati6, L. Fanucci6, A. Fazio5, D. Filippi1, C. Fontana1, A. Syntfeld-Kazuch, M. Szawlowski, T. Szczesniak, A. Szydlowski, 1 7 7 3 8 1 J. Szewinski, 1 3 9I. Zychor9 9 A. Garfagnini , P. Garosi , A. Iovene , J. Iwanowska-Hanke , B. Kuraś , G. Mistura , S. Moretto , M. Moszyński , I. Obierak , A. Olejnik , M. Parol-Wiski , 2 5 1 2 6 4 1 3 2 7 1† P. Pastore , A. Petrucci , M. Pierno , F. Romanini , A.Nuclear Ruiu , P.Research Schotanus(NCBJ), , L. Stevanato , L. Swiderski , A. Tapparo , C. Tintori , G. Viesti National Centre for 05-400 Otwock, Poland 1) Universita di Padova, Dipartimento di Fisica e Astronomia, Via Marzolo 8, I-35131 Padova, Italy 2) Universita di Padova, Dipartimento di Scienze Chimiche, Via Marzolo 1, I-35131 Padova, Italy 3) National Centre for Nuclear Research (NCBJ), 05-400 Otwock, Poland 4) Scionix Holland B.V., Regulierenring 5, 3981 LA Bunnik, The Netherlands 5) 6) ENEA, National Institute of Ionizing Radiation Metrology, C.R. Casaccia, 00123 Roma, Italy University of Pisa, Department of Information Engineering, via G. Caruso 16, 56121 Pisa, Italy 7) 8) CAEN SpA, Via della Vetraia 11, I-55049 Viareggio, Italy Wardynski & Partners, Al. Ujazdowskie 10, 00-478, Warsaw, Poland 9) MPWiK SA, Pl. Starynkiewicza 5, 02-015 Warsaw, Poland Abstract In this presentation we report on the construction and performance of a detection system designed and built within the TAp WAter RAdioactivity Real Time Monitor (TAWARA_RTM) project. The aim of the TAWARA_RTM project is to provide a platform that allows for continuous inspection of water processed at water treatment sites and enables instant reaction upon detected radiological threat. The TAWARA_RTM platform is a three-device inspection system comprising an Early Alarm Detector (EAD), a Real Time Monitor (RTM) and a Spectroscopy Detector (SPEC). The EAD is placed close to the water intake to shut off the water flux to further stages of the water treatment facility in case a substantial amount of gamma-ray emitters appear in the water. The RTM is a detection system for continuous monitoring of gross alpha and beta radioactivity in the processed water. The RTM is placed at the end of the treatment and purification process, just before the distribution. In case the RTM detects that the alpha and/or beta count rate exceeds the background level, an alarm is set and the water from the RTM device is pumped into the SPEC. The SPEC aims at identifying the radioisotopes detected by RTM using gamma-ray spectroscopy. To reduce the measurement time, a concentrator based on selective ion-exchange resins is used. In addition, a dedicated ICT infrastructure has been developed to operate the system and manage the alarms that may occur during operation. The TAWARA_RTM platform Early Alarm Detector (EAD) Scans water after first step treatment – sedimentation. Aimed at detection of large contamination at the intake point. Real Time Monitor (RTM) First-line system for on-line detection of alpha and beta emitters in water. Spectroscopy Detector (SPEC) Second-line system for identifying gamma-ray emitters in case of an alarm raised by the RTM. ICT Infrastructure Allows to control the operated devices, to collect data from the diagnostic systems and to manage the alarms. Early Alarm Detector (EAD) Real Time Monitor (RTM) 3"×3" NaI:Tl mounted in ~9 L cylindrical vessel. 24 pcs. of EJ444 sheets (EJ212 plastic scintillator covered with EJ440 powder containing ZnS:Ag), each readout by two R3550 PMTs. 25 mm thick lead shield for background reduction. ~50 L/h of raw water flow. CAEN Gammastream fully integrated digital MCA for on-line charge integration in NaI:Tl detectors. Results of calibration tests at ENEA RTM detection efficiency 5 mm (bottom) and 2 mm (top and sides) thick lead shield for background reduction. CAEN V1730 digitizers for on-line processing algorithm for pulse shape discrimination. 10 counting intervals, each 240 s duration. SPEC detection efficiency Spectroscopy Detector (SPEC) ICT Infrastructure 3"×3" CeBr3 scintillator coupled to R6233 PMT. Connects all monitoring nodes installed along the Waterwork Plant with the Central Server (CS) installed in a control room. 200 mm long and 28 mm thick BGO anti-Compton shield. 50 mm thick lead shield for background reduction. Epoxy resin filled ion-exchange concentrator (IECS) for increasing gamma-rays counting rate. CAEN DT5780 two channel digital MCA for on-line pulse height analysis in Compton-suppressed mode. Allows remote and local operators to manage the TAWARA_RTM system using web-based Graphical User Interfaces. Provides secure and lossless data communication (aggregate data, alarms, commands) using TCP/IP connections over Ethernet or 3G technology. Sources distributed inside a ring, each measurement 1800 s long. Conclusions The TAWARA_RTM platform has been designed, developed and installed in Waterworks Plant. The RTM detector sensitivity is at the level of 0.01 cps/Bq for alpha particles and 0.4-1.1 cps/Bq for beta particles. The SPEC allows for identification of <1 Bq within 1 h. The sensitivity tests with the ROCS will be carried out during next weeks in the MPWiK North Waterworks Plant in Wieliszew. Acknowledgement This work was partly supported by the project „TAp WAter RAdioactivity Real Time Monitor” funded by the EU FP7 Security Programme under grant agreement no. 312713 and by the Polish funds for science for 2014-2016 allocated to cofunded international projects – contract 3036/7.PR/2014/2 . 2E-15 www.tawara-rtm.eu www.ncbj.gov.pl [email protected]