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Untersuchung von Reziproken Salzpaaren als Medien zur Latentwaermespeicherung mit Direktem Waermetausch
No full textTHE SUITABILITY OF THE RECIPROCAL SALT PAIRS NANO3/BA(OH)2.8H2O(I) AND KNO3/BA(OH)2.8H2O(II) AS LOW TEMPERATURE LATENT HEAT STORAGE MATERIALS HAS BEEN STUDIED IN THERMOANALYTIC, STATIC AND DYNAMIC EXPERIMENTS. THE RESULTS OF THE TEMPERATURES AND ENTHALPIES OF TRANSITION OF THESE RECIPROCAL SALT PAIRS DETERMINED BY OTHER AUTHORS COULD BE CONFIRMED BY THERMOANALYTIC MEASUREMENTS. STATIC TESTS SHOWED A DECREASE OF HEAT STORAGE CAPACITY DURING THE FIRST CYCLES AND THAT A CONSTANT HEAT STORAGE CAPACITY OF 40-60 % OF THE INITIAL VALUE WAS ATTAINED AFTER 10-20 CYCLES. CYCLIC TESTS IN A DYNAMIC 10 1 - HEAT STORAGE SYSTEM SHOWED THAT THE HEAT STORAGE CAPACITY OF SYSTEM I AMOUNTS TO 210 KJ/KG IN THE TEMPERATURE RANGE FROM 57 C TO 37 C AND THAT OF SYSTEM II + 10 % H2O AMOUNTS TO 160 KJ/KG IN THE TEMPERATURE RANGE FROM 70 C TO 50 C. THE INVESTIGATIONS HAVE SHOWN THAT RECIPROCAL SALT PAIRS CAN BE USED AS HEAT STORAGE MATERIALS IN DYNAMIC LATENT HEAT STORAGE SYSTEMS. A HEAT STORAGE CAPACITY OF 80 KWH/M3 SHOULD BE REALIZED WITH SYSTEM I IN THE TEMPERATURE RANGE FROM 40 C TO 50 C, WHERE NO SATISFACTORY HEAT STORAGE MEDIUM COULD BE FOUND UP TO NOW.JRC - JR
Analysis of Cladding Residual Stresses and their Influence on the Structural Reliability of LWR Pressure Vessel
No full textTHE WORK PRESENTED HERE GIVES AN ANALYSIS OF THE CLADDING RESIDUAL STRESS (CRS) AND OF ITS IMPORTANCE FOR THE REALISTIC (BEST-ESTIMATE) LIFE-TIME PREDICTION FOR NUCLEAR REACTOR PRESSURE VESSELS. THE ANALYSIS HAS BEEN BASED ON A SURVEY OF THE PREVIOUS INVESTIGATIONS, ON THE SPECIALLY PERFORMED OWN MEASUREMENTS (ON SPECIMENS, ON A 1/5 SCALE PWR NOZZLE AND ON A 1/5 SCALE PWR VESSEL), AND ON ANALYTICAL MODELS FOR STRESS ANALYSIS, FRACTURE MECHANICS AND LIFE-TIME PRE- DICTION. THE MEASUREMENTS HAVE BEEN MADE USING THE CENTRE-HOLE, AIR-ABRASIVE METHOD. THE STRESS ANALYSIS MODEL HAS BEEN BASED ON A FICTITIOUS TEMPERATURE FIELD (FOR THE CRS SIMULATION) AND ON THE ADINA AND BERSAFE FINITE ELEMENT CODES. THE FRACTURE MECHANICS ANALYSIS HAS BEEN PERFORMED ACCORDING TO THE VIRTUAL CRACK EXTENSION METHOD (J-INTEGRAL), WHILE THE COVASTOL COMPUTER CODE HAS BEEN USED FOR THE PROBABILISTIC LIFE-TIME PREDICTION. A HIGH (250 TO 400 MPA) CRS HAS BEEN DETERMINED, AND ITS IMPORTANCE FOR THE VESSEL INTEGRITY ESTIMATED QUANTIATIVELY.NA - NOT AVAILABL
Photovoltaic Activities at the Joint Research Centre, Ispra
No full textAbstract not availableJRC - JR
The COVASTOL Program
No full textTHE COVASTOL PROGRAM HAS BEEN DEVELOPED JOINTLY BY CEA, EURATOM AND FRAMATOME. THE RESULTING CODE IS BASED ON FRACTURE MECHANICS WITH PROPAGATION EXPRESSED IN A PROBABILISTIC FORM. THE SPATIAL AND SIZE DISTRIBUTIONS FOR THE DEFECTS HAVE BEEN OBTAINED FROM 3 EUROPEAN MANUFACTURERS, A TOTAL OF 338 METERS OF LWR PRESSURE VESSEL WELDS BEING ANALYSED. THE FINAL SIZING TAKES INTO ACCOUNT THE NDE RELIABILITY AND EFFICIENCY. LOADING OF THE VESSELS HAS BEEN DETERMINED ON THE BASIS OF STATISTICAL DATA; RESULTING STRESSES AND STRESS INTENSITY FACTORS ARE COMPUTED AT DIFFERENT TIMES AND AT DIFFERENT DEPTH. PARIS LAW COEFFICIENTS ARE ALSO DETERMINED PROBABILISTICALLY TOGETHER WITH TOUGHNESS FOR WHICH IRRADIATION EMBRITTLEMENT IS CONSIDERED TAKING INTO ACCOUNT P AND CU CONCENTRATIONS. CALCULATIONS PERFORMED USING THE COVASTOL CODE AND FRENCH PWR SPECIFICATIONS SHOW THAT THE MAIN RUPTURE RISK IS DUE TO A LOCA (LARGE OR SMALL BREAK). THE RUPTURE PROBABILITY AT 40 YEARS VARIES FROM 2X10-8 TO 3X10-9 DEPENDING ON THE SAFETY INJECTION WATER TEMPERATURE (RESPECTIVELY 10 C AND 20 C). THE MOST DANGEROUS DEFECTS ARE LOCATED WITHIN THE FIRST MILLIMETERS OF THE INTERNAL LAYER AND THE MOST SENSITIVE WELD IS LOCATED AT THE BELT LINE.NA - NOT AVAILABL
Analisi Numerica e Sperimentale dello Stato di Sollecitazione di un Bocchello di Recipiente in Pressione
No full textVENGONO PRESENTATI I RISULTATI DI UNA INDAGINE SPERIMENTALE SU UN MODELLO IN ACCIAIO DI RECIPIENTE IN PRESSIONE DI TIPO NUCLEARE (BWR). LA PRESSIONE INTERNA VIENE SPINTA FINO A VALORI CHE DETERMINANO LA PLASTICIZ- ZAZIONE DELLE ZONE PIU' SOLLECITATE, IN CORRISPONDENZA DELLA CONNESSIONE TRA BOCCHELLI E MANTELLO CILINDRICO. I RISULTATI COSI' OTTENUTI VENGONO CONFRON- TATI CON QUELLI RICAVATI CON IL METODO AD ELEMENTI FINITI, SIA IN CAMPO LINEA- RE CHE NON LINEARE, APPLICANDO IL CODICE BERSAFE. IL CONFRONTO METTE IN EVI- DENZA SCOSTAMENTI MOLTO CONTENUTI O TRASCURABILI TRA I VALORI NUMERICI E QUEL- LI SPERIMENTALI IN CAMPO LINEARE. SI VERIFICA INVECE UNA PROGRESSIVA DIVERGEN- ZA TRA TALI VALORI IN CAMPO NON LINEARE ALL'AUMENTARE DELLA PRESSIONE. MODIFICAZIONI NELLA DISCRETIZZAZIONE DELLA STRUTTURA PORTANO DEI MIGLIORAMEN- TI, CHE PERO' NON SONO SUFFICIENTI A LIMITARE LE DIFFERENZE TRA RISULTATI NU- MERICI E SPERIMENTALI ENTRO VALORI SODDISFACENTI, COME IN CAMPO LINEARE.NA - NOT AVAILABL
Esarda Bulletin no.6 April 1984
No full textESARDA is an association initially formed to advance and harmonize research and development for nuclear safeguards whose scope has in recent year expanded as the number and type of its working groups’ activities below indicates. Esarda is currently composed of about 30 laboratories, private and governmental institutions worldwide.
Within Esarda (http://esarda.jrc.ec.europa.eu/), a number working groups have been over the years established and active namely: Techniques and Standards for Destructive Analysis, Techniques and Standards for Non-Destructive Analysis, Containment and Surveillance, Novel Approaches / Novel Technologies, Implementation of Safeguards, Verification Technologies and Methodologies, Training and Knowledge Management, Editorial Committee.
ESARDA publishes a Bulletin containing scientific and technical articles related to safeguards and verification (and beyond) as well as news and reports related to the ESARDA activities. This publication appears generally twice a year. In addition, thematic special issues are published as proposed by the ESARDA community. The Bulletin Editorial Board is composed of about 10 experts in the various technical and scientific fields related to safeguards. They are all actively engaged in safeguards R&D or in safeguards implementation and other fields. The Editorial Board decides the contents of the Bulletin, selects the papers to be published and reviews them before publication. All ESARDA editorial activities are carried out at JRC Ispra.
Scientific and technical papers submitted for publication in the peer reviewed section are reviewed by independent authors and by members of the Editorial Committee. The bulletin is currently submitted to Thomson Reuters for evaluation in view of citation. ESARDA Bulletin is published jointly by ESARDA and the Joint Research Centre of the European Commission and distributed free of charge to over 1100 registered members, libraries and institutions worldwide.JRC.E.8 - Nuclear securit