Thermo Scientific URANUS Mass Spectrometer for Uranium ...

1 Thermo Scientific URANUSMass Spectrometer for UraniumHexafluoride AnalysisPart of Thermo Fisher Scientificm a s s s p e c t r o m e t r yHigh precision and fully computer controlled isotope ratiomeasurement of molecular beam ionsource for up times exceeding1500 hours of Spectrometer for Uranium Hexafluoride AnalysisThermo Scientific URANUSMass Spectrometer for Uranium Hexafluoride Analysis2 Design Considerations Uranium hexafluoride is the gaseous working medium used in procedures to enrich the fissionable 235U isotope by diffusion, jet, laser orcentrifuge processes on an industrial highly active gas must be handled withgreat care to protect the operators and to avoiddamage to the instruments involved. All the modules as well as the safety devices of theThermo Scientific URANUS mass spectrometercomply with these mass Spectrometer Characteristics< accuracy for 235U / 238U - ratio< external precision for 235U / 238U - ratio< 1 mg/h UF6 consumption Accuracy Precision ReliabilityAccuracy3 High PerformanceThe Thermo Scientific URANUS mass Spectrometer system sets the new industrystandard for the reliable day-to-day isotopicanalysis of Uranium hexafluoride with highest precision.

2 The high performance isbeneficial for the evaluation of raw materials ( feed ), control of products with enriched 235U content andcontrol ofwaste materials ( tails ) depleted in isotopic analyses may be appliedon-line to process streams as well as tomanually acquired pipette samples. Theymay even occur in the development ofenrichment processes to measure the verysmall changes of isotope ratios by singleprocess elements, or in the establishment ofnew isotope standard materials by measuring a new standard against an oldstandard at highest precision. The URANUS mass Spectrometer system meets in a ll its modules the specialdemands of the Uranium hexafluoride working medium. It provides the highestprecision isotope ratio determination whilesatisfying the industrial standards for reliability, safety and operation URANUS mass Spectrometer sets the new industry standard for reliability, safety and operation timeThermo Scientific URANUSMass Spectrometer for Uranium Hexafluoride Analysis4 History of Uranium HexafluorideIsotopic AnalysisThe URANUS mass Spectrometer systemfully utilizes the very extensive expertise inthis highly specialized field of analyticalmass than 70 MAT mass spectrometersfor Uranium hexafluoride isotopic analysishave been installed all over the world.

3 Inlaboratories as well as in nuclear fuelenrichment has been a continuing implemen-tation of application experience and designimprovements throughout these years,including: Improvements for the safe handling of thehighly active sample gas UF6. Development of the highly precise multi-collector sample/reference measurementof major and minor Uranium isotope abun-dances. Extension of the MS isotope analyzer soperating times with UF6inflow. Adaptation to various sample conditions,at low and high pressure. Automatic control of sample and reference selection/introduction, measurement, data acquisition and data development of modern nuclearfuel enrichment processes as well as thecontrol of enrichment plants utilizing thesemodern processes were accompanied byuranium hexafluoride mass URANUS mass Spectrometer analytical performance is the result of vast experience in Uranium hexafluoride isotopic analysisDevelopment of UraniumHexafluoride MassSpectrometer ModelsCH4-UF1962 - 1967CH5-UF1967 - 1973UF51967 - 1971 MAT 5111971 - 1978 MAT 250 UF1979 - 1982 MAT 2811985 - 20045 Features High precision and fully computer-controlled isotope ratio determination ofuranium hexafluoride.

4 Choice of flexible inlet systems for computer-controlled sample introductionfrom reservoirs and process lines. Magnetic ion separating system employing stigmatic focusing for high ion transmission and enhanced mass dispersion. Molecular beam ion source for up timesexceeding 1500 hours of UF6inflow. Cryo-pumped molecular beam ion sourceregion for fast removal of superfluoussample material, providing an extremelylow memory factor. Standard quadruple Faraday collector,with deep bucket design, completelyshielded for simultaneous determinationof 234U and 236U minor isotope abundanceswith the main isotope measurement. The system is computer-controlled to perform automated and unattended sample selection and sample introduction, analyzer control and datacollection, data evaluation and data printout, utilizing a software packagestructured for flexibility of analytical,monitoring and maintenance procedures.

5 Secondary Electron Multiplier system(SEM) for analysis of trace componentsby ion InletInlet System Individual batches for the intermediatestorages of sample and standard material, minimizing the consumption ofsuch very valuable material through themeasurement cycle. For UF6sample pressures between and 200 mbar. Pneumatically operated valves with KEL-Fgaskets ensuring leak rates below 10-10mbar L/s, even with more than100,000 switch cycles. Turbomolecular pumping for fast samplechange and low inlet system memory. Special cold traps to trap surplus samplematerial, safety devices to avoid anyrelease of Uranium hexafluoride to flexibility in analytical, monitoring and maintenance proceduresThermo Scientific URANUSMass Spectrometer for Uranium Hexafluoride Analysis6 Pressure Transducer Defined sample inlet pressure.

6 Set- and permanent read out by theThermo Scientific Isodat software. Inlet pressure as method parameter inautomated sequences. For sensitivity check by evaluating the ratio of ion current versus Inlet and Open Ion Source Includes one cryo trap for the inlet jetenvironment and another cryo trap to condense all non-ionized sample material. Focuses both the UF6molecular beam andthe electron beam with very high efficien-cy to avoid any source contamination. Handles the UF6molecules at very lowthermal excitation to avoid distortion ofthe mass spectral base line bymetastable ion continuum . Achieves very high sensitivity at low sample consumption, another prerequisitefor a low memory/long time operation. Provides specially d esigned filament andultra-clean crossbeam operation for uptimes exceeding 1500 hours of System Analyzer system evacuated with ion getter pumps providing a complete separation to atmosphere.

7 A separating valve between the ionsource region and the analyzer providessource maintenance while the analyzersection remains pumping. Turbomolecular pumps at the inlet systemfor initial analyzer pump-down. All vacuum functions are controlled by anintegral logic circuitry to be high sensitivity at low sample consumptionFlexibility7 AnalyzerThe analyzer of the URANUS mass Spectrometer is based on theunique ion optics of the Thermo Scientific TRITON thermal ionisa-tion MS, proven in more than 150 installations OpticsThe unique cup configuration of the URANUS mass Spectrometer isespecially beneficial for UF6isotope ratio analysis . The large massdispersion of 810 mm is based on an ion optical magnification ofabout a factor o f 2, providing generous space for the novel collectorarray.

8 This has the additional advantage of increasing the focaldepth and cup Performance Faraday CupsThe Faraday cups are the largest ever produced for a commercialmulticollector. They are machined from solid carbon to guaranteeuniform response, high linearity, low noise and long lifetime. TheFaraday cups are designed to completely eliminate the need for cupfactors. The effect of ion optical magnification on cup performanceis depicted in the graph. With increasing ion optical magnification the divergence anglesof the ion beams are reduced and the dispersion is increased. As aresult, cups can be wider and deeper. Scattered particles releasedat the cup s side walls by the incoming ion beams are less likely toescape and d o not alter the true ion URANUS is a completely newly designed mass Spectrometer dedicated for high precision gas isotope ratio measurements with unique molecular beam inlet techniqueThermo Scientific URANUSMass Spectrometer for Uranium Hexafluoride Analysis8 The AmplifierEach Faraday cup is connected to a currentamplifier.

9 The amplifier signal is digitized by a high linearity voltage to frequency converter with an equivalent digital resolution of 22 bit. This ensures sub-ppmdigital resolution of all measured signalsindependent of the actual signal amplifiers are mounted in a doublyshielded, evacuated and thermostated housing with a temperature s tability of dynamic range of the currentamplifiers is extended to 50 V in positive ion detection mode. The extended dynamicrange supports the measurement of largeisotope ratios, because it directly leads toan improved signal to noise ratio for theminor SystemA Secondary Electron Multiplier (SEM) withan ion counting detector is optionally available. The SEM system allows t hedetermination of the Uranium 233 isotopeand trace impurities of UF6samples withhighest Scientific URANUSMass Spectrometer for Uranium Hexafluoride Analysis10 SoftwareThe Thermo Scientific Isodat software suite is optimized for therequirements of routine analysis , providing the ease of use for basicoperation as well as the flexibility for advanced experiments.

10 Theintuitive user interface provides full URANUS system control andcomprises all tools for data acquisition and evaluation. T he Isodatsoftware is an integral part of the system architecture enabling theanalytical power and flexibility of the URANUS mass controlAll aspects of the mass Spectrometer are controlled by software,including ion generation, mass separation and ion detection. Controlof the ion source allows manual tuning, auto tuning, as well as storage and retrieval of ion source parameters. System configura-tions can be easily defined. Different configurations representingdifferent analytical setups can be stored and retrieved. AutomationThe system is designed to fully automatically execute pre-definedprocedures and run sequences of analyses, including ArchitectureThe Isodat Script Language (ISL) is the tool giving the expert user full access to the mass Spectrometer , the inlet systems andadditional user-supplied devices.