The ability to calculate accurately the performance of light water reactor (LWR) fuel rods under long-term irradiation conditions and various operational transients and hypothetical accidents is an important objective of the reactor safety investigations. The IAEA Coordinated Research Project(CRP) FUMAC (Fuel Modelling in Accident Conditions), focuses on the accident conditions and supports the improvement and development of computer modelling codes by compilation and analysis of experimental data for codes validation and for better understanding and enhanced safety of nuclear fuel behavior. The INRNE team participates in this project with simulations and analyses by TRANSURANUS fuel performance code. This report presents the results of simulation of the Halden IFA650.11 experiment with WWER fuel, pre-irradiated up to 56 MWd/kgU and tested under LOCA conditions at Halden. The goal of this investigation is to study TRANSURANUS code predictions of WWER fuel rods under off-normal conditions (LOCA) and the changes of the fuel rod structure and geometry of fuel and cladding.

Themove to high burnup fuels, new fuel designs and introduction of new claddingmaterials have generated a need to re-examine and verify the validity of the safety criteria for LOCA accidents. Fuel designers and nuclear research community, as well as the safety authorities rely on fuel performance codes for predicting the behaviour and life-time of fuel rods. The simulation tools are developed and validated on the basis of experimental results. The present report demonstrates the team capacity to analyse LOCA conditions on the base of the Halden experiment IFA 650.2 by means of the TRANSURANUS code and results are compared with experimental data.

Complexes of poly(propylene imine) dendrimers D8[DAB-dendr-(NH2)8] and D32 [DAB-dendr-(NH2)32] were prepared by interaction of the dendrimers with transition metal salts such as FeCl3.6H2O; CoCl2.6H2O; CuCl2.2H2O; VOSO4.5H2O; Na2MoO4.2H2O and Na2WO4.2H2O at room temperature in aqueous solutions. The content of metal ions in the complexes was found to be from 8.2 to 69.6mg metal ion/g polymer carrier. The complexes were characterized by using IR, UV–VIS, Moessbauer spectroscopy and EPR. The anticipated co-ordination structure of the compounds was suggested. It was found that the order of the catalytic activity of the complexes of poly(propylene imine) dendrimers D8 and D32 in the reaction of epoxidation of cyclohexene with organic hydroperoxides such as tert-butyl hydroperoxide (t-BHP), ethylbenzene hydroperoxide (EBHP) and cumene hydroperoxide (CHP) was as follows: D32-MoО22+>D32-VО2+>D32-WО22+ >D32-Co2+>D32-Cu2+>D32-Fe3+. The order of reactivity of organic hydroperoxides in the reaction studied was: t-BHP>EBHP>CHP.

Copolymer products were prepared by radiation grafting of 4-vinylpyridine onto films of low-density poly(ethylene) and poly(tetrafluoroethylene) (PE-graft-P4VP and PTFE-graft-P4VP, respectively). The corresponding metal complexes were in turn obtained by interaction of the radiation-grafted copolymers with aqueous solutions of various salts such as FeCl3·6H2O, CoCl2·6H2O, VOSO4·5H2O, Na2MoO4·2H2O and Na2WO4·2H2О at room temperature. The content of metal ions was found to be within 0.53–10.93mgmetal/g polymer carrier. The polymer-supported metal complexes were identified by infrared spectroscopy and electron paramagnetic resonance analyses. The structure of the iron-containing polymeric materials was evaluated by Mossbauer spectroscopy. Some of the modified copolymers were also studied as polymer-supported catalysts of model reactions such as oxidation of cyclohexene with organic hydroperoxides. The catalytic activity of the molybdenum-containing polymer complex catalyst (P4VP-MoO22+) in the principal epoxidation reaction was higher than that of the vanadium-containing (P4VP-VO2+) one, whereas, the opposite order of activities was found for the side reaction of allylic hydroxylation of cyclohexene. Under selected reaction conditions, the yields of the principal reaction products cyclohexene oxide (1,2-epoxycyclohexane) and 2-cyclohexene-1-ol were 76.2% and 18.0%, respectively.

The TRANSURANUS code is a computer program for the thermal and mechanical analysis of fuel rods in nuclear reactors [1,2]. An actual overview of the whole TRANSURANUS project can be found in [3]. Intensive work has been performed for verification of fuel centre temperatures calculated with standard options of TRANSURANUS, as they would be used in blind predictions [4]. The main part of the verification has been based on in-pile temperature measurements from the OECD Halden Reactor Project. The International Fuel Performance Experiments Database (IFPE) [5] is used as complementary source of valuable experimental data. Our previous analyses of IFPE data covered irradiations of fuel for Russian-type WWER reactors (experiment Sofit 1.1 [4,6]). In this work we report on a further analysis regarding UO2 fuel for Western-type reactors: • Fuel centre temperatures measured in the experiments Contact 1 and Contact 2 (in-pile tests of 2 rods performed at the SILOE reactor in Grenoble, France, closely simulating commercial PWR conditions); • Fission gas release data derived from postirradiation examinations of 9 fuel rods belonging to the High-Burnup Effects Programme, task 3 (HBEP3). The results allow for a comparison of predictions by TRANSURANUS for the mentioned Westerntype fuels with those done previously for Russiantype WWER fuel [6]. The comparison has been extended to include fuel centre temperatures as well as fission gas release. The present version of TRANSURANUS includes a model that calculates the production of Helium. The amount of produced Helium is compared to the measured and to the calculated release of the fission gases Xenon and Krypton.

The nucleus Ho-166 was studied with thermal and average resonance neutron capture and with (d,p) and (d,He-3) reactions. We have devoted a large effort to the measurements of gamma gamma-coincidence spectra in the broad energy interval 50-6243 keV. From these data and those of previous studies, the level scheme has been developed containing levels grouped into 23 rotational bands below 1 MeV. Of these, six bands are new and several others, known previously, have been modified and expanded based upon our experimental data. In all, 32 new levels have been identified. Of particular note has been the identification of two rotational bands whose underlying structure consists of gamma-vibrational states built upon the two lowest energy quasiparticle states in Ho-166. Two new Gallagher-Moszkowski matrix elements were determined: E-GM(p7/2(-)[523]+/-n5/2(-)[523]) = - 108.5 keV and E-GM{(p7/2(-)[523]+/-n7/2(+)[633])+/-Q(22)} = + 138.2 keV. The resultant level scheme is in good agreement with semiempirical and quasiparticle phonon models where residual interactions have been taken into account. Suggestions are given for further experimentation on Ho-166 level structure using existing technology.

Levels of 166 Ho were studied using thermal and average resonance neutron capture and with the (d,p) and (d, 3 He) reactions. We have devoted a large efiort to the measurements of the ∞∞-coincidence spectra in the broad energy region 50 { 6243 keV. Based on these data and those of earlier studies, the levels are grouped into 23 rotational bands. Among them are 6 new ones. The results are in good agree- ment with the semiempirical and quasiparticle-phonon model, where Coriolis and residual interactions are taken into account. Details of model interpretation have been presented in a previously published paper.

Heterogeneous molybdenum-containing polymeric catalysts for the epoxidation of alkenes by organic hydroperoxides were prepared by a simple treatment of the chelating ion exchange resins (polyampholites) Amberlite IRC718, Amberlite IRC748 and Duolite C467 (Rohm&Haas, USA) with both the aqueous solution of sodium molybdate at pH 3.5 and solution of molydenyl acetylacetonate in toluene. The formation of the catalytically active centres by the interaction of the oxomolybdenum species from the reaction solution with ligand functional groups of the ion exchangers was proved. The stability of these polymeric complexes on multiple use with the epoxidation of cyclohexene by tert-butylhydroperoxide (TBHP) in the absence of an inert solvent at temperature 79°C and initial TBHP concentration of 1.2–1.3 mol l−1 was studied.

The separation of some tricyclic spiro esters on fused-silica capillary columns coated with dimethylsiloxane, cyanopropyl methyl siloxane and poly(ethylene glycol) stationary phases was investigated. Retention indices were determined at two temperatures to interpret their chromatographic behaviour. The repeatability of the measurements was 0.2, 0.3 and 0.5 index units. The influence of the polarity of the stationary phases on the chromatographic retention of these tricyclic spiro esters is discussed.

Heterogeneous polymeric catalysts containing Mo, V and Ti for the epoxidation of alkenes by organic hydroperoxides were prepared by a simple modification of the weakly acidic cation exchanger Wofatit CA 20 (Germany) with aqueous solutions of the corresponding inorganic salts. The molybdenum-containing catalyst showed the highest activity for the epoxidation of cyclohexene in benzene solution of t-butylhydroperoxide (TBHP, 0.490–1.200 mol l−1) at 79°C. The catalytic activity for alkenes with different structures was evaluated and compared to other catalysts under the similar conditions of cyclohexene epoxidation. Some data concerning the catalyst stability on heating and multiple recycling were also obtained.

Retention indices or five 1-alkenes, seven branched alkenes and five cycloalkenes and the corresponding epoxides were determined at two temperatures on a fused-silica capillary column coated with cyanopropyl methyl siloxane to interpret their chromatographic behaviour. The standard deviation was 0.2 index units.

Summary  The separation of some epoxystyrenes on fused silica capillary columns coated with poly(ethylene glycol) was investigated, Retention indices were determined at two temperatures to interpret chromatographic behaviour, The standard deviation was 0.3 index units.