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| | výběr: kategorie AER| nalezeno záznamů: 125 | |
| [1] | Advanced Fuel Cycles for VVER-1000 Reactors| Semchenkov Y.M., Pavlovichev A.M., Pavlov V.I., Spirkin E.I., Styrin Y.A. and Kosourov E.K. | | RRC Kurchatov Institute, Moscow, Russia | | Main stages of Russian uranium fuel development regarding improvement of safety and economics of fuel load operation are presented. Intervals of possible changes in fuel cycle duration have been demonstrated for the use of current and perspective fuel. Examples of equilibrium fuel load patterns have been demonstrated and main core neutronics parameters have been presented. Problems on the use of axial blankets with reduced enrichment in VVER-1000 fuel assemblies are considered. Some results are presented regarding core neutronic characteristics of VVER-1000 at the use of regenerated uranium and uranium-plutonium fuel. Examples of equilibrium fuel cycles for the core partially loaded with MOX fuel from weapon-grade plutonium are also considered. | kategorie:AERpublikováno:17th AER, 23-29 September 2007, Yalta, Crimea, Ukraine - No.004 | | umístění:| Tomáš Vytiska | | | | | | | |
| [2] | Russian Fuel Assemblies Implementation Experience at SUNPP-2| N.N. Stepanov, V.N. Zhestkov | | Nuclear Safety Department of SUNPP | | The paper contains general information on switching SUNPP Unit 2 to usage of alternative design fuel assemblies. There are 3 Units in operation at SUNPP with total electrical capacity of 3000 MWt, and each of them has its own specific characteristics. The fuel of alternative design (TVS-A) manufactured by TVEL Corporation with gadolinium burnable absorber integrated into fuel elements has been operating at Unit 2 since 2005.
Implementation of modified fuel is considered as design changes, and therefore it should be approved, and according to the Law of Ukraine On use of nuclear Energy and Radiation Safety all necessary approval should undergo the State expertise on nuclear and radiation safety. Transient fuel cycles (containing both TVS and TVS-A) was performed by SUNPP's physicists (by means of KASKAD computer code) by use recommendations of RRC Kurchatov Institute experts and was approved in according to the existing procedure.
The paper also contains detailed information on the specific characteristics of the SUNPP Unit 2 reactor core, main stages in course of implementation of new fuel types, characteristics of mixed fuel cycles, comparison of calculated and measured power distribution, comparison of calculated and experimental data. | kategorie:AERpublikováno:17th AER, 23-29 September 2007, Yalta, Crimea, Ukraine - No.005 | | umístění:| Tomáš Vytiska | | | | | | | |
| [3] | Experience of Burnup Increase and Fuel Use Improvement at the Kalinin NPP Units with TVSA| Peskov R.A., Romanov A.I., Samoilov O.B. | | OKBM | | A complex of scientific, experimental, development and engineering activities was carried out to master TVSA fabrication and to start their commercial operation. The results of the mentioned activities provided the required basis for systematic improvement of the FA design, increase of its efficiency, and introduction of flexible and cost effective fuel cycles based on the new FA designs to meet the consumers' needs.
TVSA was introduced into the reactor core of Kalinin NPP Unit 1 in 1998-2002 (14-18th fuel loadings) as a means to compensate for TVSA twisting. During the 14th through 16th fuel loadings, 36 and 60 fresh TVSA were loaded as part of the 15th and 16th makeups and evenly distributed in the reactor core, which led to straightening of the core. | kategorie:AERpublikováno:17th AER, 23-29 September 2007, Yalta, Crimea, Ukraine - No.006 | | umístění:| Tomáš Vytiska | | | | | | | |
| [4] | Extension of VVER-440 Fuel Cycles Using Improved FA Design| P. Mikoláš, J. Švarný | | ŠKODA JS a.s., Pilsen, Czech Republic | | Practically full five years cycle has been achieved at NPP Dukovany in the last years. There are two principal means how it could be achieved. First, it is necessary to use fuel assemblies with higher fuel enrichment and second, to use fuel loading with very low leakage. Both these conditions are fulfilled at NPP Dukovany at this time.
However, the efficiency of fuel cycle can be improved by increasing the fuel residence time in the core up to six years. There are at least two ways how this goal could be achieved. The simplest way is to increase enrichment in fuel. There exists a limit, which is 5.0 w% of U235. Taking into account some uncertainty, the calculation maximum is 4.95 w% of U235. The second way is to change fuel assembly design. There are several possibilities, which seem to be suitable from the neutron - physical point of view. The first one is higher mass content of uranium in a fuel assembly. The next possibility is to enlarge pin pitch. The last possibility is to omit FA shroud. This is practically unrealistic anyway, some other structural parts must be introduced. | kategorie:AERpublikováno:17th AER, 23-29 September 2007, Yalta, Crimea, Ukraine - No.007 | | umístění:| Tomáš Vytiska | | | | | | | |
| [5] | Recent Core Design And Operating Experience in Loviisa NPP| M. Antila, T. Lahtinen | | Fortum Nuclear Services Ltd, Espoo, Finland | | This paper demonstrates the recent years experience in core design and operating in the Loviisa NPP. The two units of Loviisa NPP are run with reduced core and 1500 MW power. Both units are currently in nearly equilibrium 3-batch fuel cycle. Two different fuel types are used: first unit (Loviisa-1) runs with BNFL fuel whereas TVEL fuel is used in the 2nd unit (Loviisa-2).
The paper demonstrates recent core loading patterns together with a short discussion on their properties. Main properties of the two used fuel types are shortly described. The major part of the presentation consists of comparison of measured and computed core characteristics for TVEL and BNFL fuel. Comparison is performed for a couple of recent cycles at both units.
An insight into future challenges of core loading pattern design at Loviisa NPP is also given. This includes plans to shift from current 3-batch loading to 4-batch loading, which means increased enrichment and burn-up. | kategorie:AERpublikováno:17th AER, 23-29 September 2007, Yalta, Crimea, Ukraine - No.008 | | umístění:| Tomáš Vytiska | | | | | | | |
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