Component Category: -Coolant, cover-gas and Primary cooling system including heat exchangers
11 documents found
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On-line gamma spectroscopy system for observation of the cover gas of KNK II, description and instruction Messplatz on-line Gammaspektroskopie zur Schutzgasueberwachung an der KNK II, Beschreibung und Betriebsanleitung
Hoffmann, G.;Letz, K.DKernforschungszentrum Karlsruhe GmbH (Germany)
KFK-PSB--01.02.17P02A - German - 1978
Abstract: To get more information about the further evolution of defected fuel pins in the sodium cooled fast reactor KNK II, an on-line measuring system to observe the cover gas activity was developed. A computerized gamma-spectroscope evaluates on-line some significant photo-peaks. The paper describes the hardware and software and gives an instruction manual for this system
Key words: activity levels;cover gas;failed element detection;failed element monitors;gamma spectroscopy;knk-2 reactor;on-line systems;performance testing;reactor safety
R&D Category: -Failure and failure propagation mechanisms
display the document: 34086277.pdf
On-line gamma spectroscopy measuring station for cover gas monitoring at KNK II
Hoffmann, G.;Letz, K.DKernforschungszentrum Karlsruhe G.m.b.H. (Germany, F.R.). Inst. fuer Reaktorentwicklung;Kernforschungszentrum Karlsruhe G.m.b.H. (Germany, F.R.). Projekt Schneller Brueter
KFK--2797 - English - 1980
Abstract: An automated Ge-
Key words: automation;cover gas;failed element monitors;fuel cans;gamma spectrometers;ge semiconductor detectors;knk-2 reactor
R&D Category: -Failure detection
display the document: 11536175.pdf
Release of fission products from the KNK II fuel element failure and search for released fuel in the primary sodium Freisetzung von Spaltprodukten aus dem KNK II-Brennelementschaden und aktivierungsanalytische Suche nach ausgetragenem Brennstoff im Primaernatrium
Hanke, H.-D.;Clauss, H.;Stamm, H.-HKernforschungszentrum Karlsruhe GmbH (Germany)
KFK-PSB--01.02.17P24B - German - 1980
Abstract: A first fuel element cladding failure occurred in the KNK II reactor on April 1st, 1979. The activity concentrations of radio nuclides are reported from four sodium samplings: the last sampling before the fuel failure, two samplings with the failed element in the core and one sampling after removal of the failed fuel element. Only I-131, Cs-136 and Cs-137 were released from the failed fuel into the primary sodium. The release fraction of Cs-137 was 5.2 % of a fuel rod inventory. The specific activities of some radio nuclides (Zn-65, Ag-110m, Sb-124,...) in the primary coolant were determined by neutron activation analysis. In addition, efforts were made to find non-radioactive cesium and released fuel in the sodium. The applied procedure is described in detail. Neither in the recent samples nor in Na stock samples from the time before nuclear operation of the plant any cesium or fuel was detected. From detection limits it was concluded, that the Cs content in the 21 metric tons of primary sodium was smaller than 10 mg and the content of fuel smaller than 1.1 mg
Key words: after-heat removal;antimony 124;cesium 136;cesium 137;defects;delayed neutron analysis;fission product release;fuel element failure;iodine 131;knk reactor;knk-2 reactor;neutron activation analysis;neutron detection;primary coolant circuits;silver 110;sodium;testing;zinc 65
R&D Category: -Failure and failure propagation mechanisms
display the document: 34086281.pdf
Determination of radionuclides in the primary sodium and in the primary cover gas Argon and of the Tritium content of the ternary water-/steam circuit of KNK II at the start-up of the second core Bestimmung von Radionukliden im Primaernatrium, im primaeren Schutzgas Argon und von Tritium im tertiaeren Wasser-/Dampfkreislauf der KNK-II bei der Inbetriebnahme des Zweitkerns
Stamm, H.-H.;Hanke, H.-D.;Clauss, H.;Schmidt, KKernforschungszentrum Karlsruhe GmbH (Germany)
KFK-PSB--01.02.17P11A - German - 1983
Abstract: During the start-up operation of KNK II with its second core the plant was operated at power levels of 40, 80 and 100 % for several days each. During this phase a radiochemical program was performed with measurements of the radionuclide content in the primary sodium and primary cover gas Ar and of the Tritium content of the ternary water-/steam circuit. The results of these measurements are described in this report
Key words: argon;cover gas;knk-2 reactor;primary coolant circuits;radiochemical analysis;secondary coolant circuits;sodium;tritium
R&D Category: Commissioning and start-up testing, rise to power, transient testing
display the document: 34086278.pdf
Determination of the isotopic ratios Xe131/Xe134 in the cover gas of KNK II (Leaker phase from 6. 4. to 2. 5. 85) Bestimmung der Isotopenverhaeltnisse Xe-131/Xe-134 im Covergas der KNK II (Leakerphase vom 6.4. bis 2.5.85)
Stieglitz, L.;Becker, R.;Will, RKernforschungszentrum Karlsruhe GmbH (Germany)
KFK-PSB--01.02.17P33A - German - 1985
Abstract: The Institute of Hot Chemistry of the Nuclear Research Center Karlsruhe has developed an experimental method to determine the ratios of noble fission gases in the ppm range with uncertainties of a few percent. This is especially of interest for the Xenon isotopes 131 and 134, the ratio of which is different for U235 and Pu239 fission. For KNK II with the Uranium/Plutonium fuel of the test zone assemblies and the Uranium fuel of the driver zone assemblies, a comparison of measured and calculated ratios could therefore allow to distinguish between a failure in one of the two zones with different fuel type. In this report the experimental method is explained and experimental results are presented for one special fuel failure in KNK II
Key words: delayed neutron analysis;failed element detection;fuel element failure;isotope ratio;knk-2 reactor;plutonium 239;reactor operation;reactor safety;uranium 235;xenon 131;xenon 134
R&D Category: -Failure and failure propagation mechanisms
display the document: 34086282.pdf
Radiochemical surveillance of KNK primary sodium
Stamm, H.H. (Kernforschungszentrum Karlsruhe G.m.b.H. (Germany, F.R.). Inst. fuer Radiochemie);Stade, K.C. (Kernkraftwerk-Betriebsgesellschaft m.b.H., Eggenstein-Leopoldshafen (Germany, F.R.))KFK--4279 - English - 1987
Abstract: After 400 effective full power days (EFPD) and a maximum fuel burnup of 100000 MWd/t the reactor was shutdown in August 1982. After replacing the total KNK II/1 core by the second fast core KNK II/2, the plant went into operation again in August 1983. In August 1986 nearly 400 EFPD were achieved with the second core KNK II/2. It is foreseen to exent the operation up to 720 EFPD with the core KNK II/2. KNK II is widely used as is governed by the experimental program rather than by energy production. Radionuclides and other impurities in the primary sodium were determined for plant surveillance as well as for an extensive radiochemistry program. This experimental radiochemistry program includes investigations of radionuclide deposition on pretreated surfaces under flowing sodium and development of new methods for trapping of radionuclides from primary sodium. Aim of this work is to minimize the radiation exposure associated with maintenance and repair work. (orig./HP)
Key words: contamination;corrosion products;deposition;fission products;knk-2 reactor;optimization;primary coolant circuits;radiation doses;reactor maintenance;repair
R&D Category: any or undefined
display the document: 19036786.pdf
Filtration experiments of the KNK II primary sodium
Stamm, H.H. (Kernforschungszentrum Karlsruhe G.m.b.H. (Germany, F.R.). Inst. fuer Radiochemie);Stade, K.C. (Kernkraftwerk-Betriebsgesellschaft m.b.H., Eggenstein-Leopoldshafen (Germany, F.R.))KFK--4279 - English - 1987
Abstract: The separated particles of the KNK primary sodium are a result of a normal corrosion rate by using ferritic and austenitic steels in sodium. Similar particle distributions and concentrations were found in primary circuits of other breeder plants (EBR-II et al). The experimental results of the particle concentration in the KNK primary sodium were lower than the theoretical calculation. Based on a corrosion rate of 0.5 micron/y for austenitic steels and a corrosion rate of 1.5 mg/square-cm y for a ferritic steel used in KNK as structure material an equilibrium particle concentration of 1.066 mg/kg Na was calculated. The experimental results of particle size are not in agreement with theoretical calculation of the BACCHUS code. (orig.)
Key words: austenitic steels;corrosion products;distribution;ferritic steels;knk-2 reactor;particle size;primary coolant circuits
R&D Category: any or undefined
display the document: 19036785.pdf
Cover gas purification experience at KNK
Richard, H.;Stade, K.Ch. (Kernkraftwerk-Betriebsgesellschaft m.b.H., Eggenstein-Leopoldshafen (Germany));Stamm, H.H. (Institute of Radiochemistry, Nuclear Research Center, Karsruhe (Germany))IWGFR--61 - English - 1987
Abstract: KNK II is an experimental, sodium cooled fast breeder reactor. The reactor was operated until 1974 with a thermal core (KNK I). The plant was converted into a fast breeder reactor (KNK II) from 1974 to 1977. The commissioning of KNK II was started in October 1977 with the first fast core KNK 11/1. After 400 effective full power days (EFPD) the reactor was shut down in August 1982. After replacing the complete core by the second fast core KNK 11/2, the plant went into operation again in August 1983. In August 1986 nearly 400 EFPD were achieved with the second fast core. Argon is used as cover gas in the primary and secondary sodium systems of KNK. In former times fresh argon was supplied by a bundle of gas cylinders. Later on a liquid argon supply was installed. Purification of cover gas is done by flushing only. During KNK I operation no fuel failures occurred. The primary cover gas activity was characterized by the formation of Ar-41, only small quantities of fission gas were measured, released from 'tramp uranium'. Therefore, no problems existed during KNK I operation with regard to radioactive gas disposal. However, after start-up of KNK II, several fuel elements failed. Until August 1986, five fuel failures were observed, two in KNK 11/1, and three in KNK 11/2. Sometimes, operation with defective fuel pins caused problems when fission gases leaked into the containment atmosphere, and the access had to be restricted. The purging rate of the primary cover gas was limited by the capacity of the charcoal filters in the delay line. Of all non-radioactive impurities, hydrogen (Hz) and nitrogen (N2) were of most importance in the primary cover gas. Main source of both impurities was the ingress of air and atmospheric moisture during handling operations in shutdown periods. An other possible source for hydrogen might be a release from the steel-clad zirconium hydride, used as moderator in the moderated driver fuel elements. Additional nitrogen may diffuse through the freeze seals of the primary valves located in the nitrogen-filled 'primary cell' of the plant
Key words: argon;cladding;cover gas;fission products;fuel element failure;hydrogen;knk-2 reactor;nitrogen;primary coolant circuits;purification;reactor protection systems;reactor safety;secondary coolant circuits;sodium;steels;zirconium hydrides
R&D Category: Safety aspects
display the document: 33011383.pdf
Radiochemical surveillance of KNK primary sodium Radiochemische Ueberwachung des Primaernatriums von KNK
Stamm, H.-H.;Stade, K.ChKernforschungszentrum Karlsruhe GmbH (Germany), Kernkraftwerk-Betriebsgesellschaft mbH (DE)
KFK-PSB--01.02.17P51A - German - 1987
Abstract: Radiochemical surveillance of the KNK primary sodium has been performed now for 15 years with 953 effective full-power days. The overflow method used for sodium sampling proved to be reliable. Different crucible materials have been used for different analytical tasks. The amount of radionuclides in the primary system has not given restrictions to plant operation at any time. On-line gamma spectroscopy on pipings and components of the primary circuits was accomplished in reactor downtimes. Activity depositions on the walls were dominated by Ta-182 after KNK I operation. Main deposited activities at KNK II were Mn-54 (fresh core) and after operation with failed fuel Cs-137, in cover gas areas together with Zn-65. Efficient experimental radionuclide traps for the removal of Mn-54, Zn-65 and Cs-137 from the primary coolant were tested successfully. The dose rates on primary pipes and components of KNK I and KNK II were lower by an order of magnitude compared to water-cooled reactors. This is in good agreement with experiences from LMFBR's in other countries. The resulting average yearly accumulated personal dose rate was 0.21 man-Sv at KNK, compared to 3.9 man-Sv at German light-water-cooled power reactors
Key words: cesium 137;cold traps;deposits;dose rates;gamma spectroscopy;knk reactor;knk-2 reactor;manganese 54;monitoring;primary coolant circuits;radiochemical analysis;radioisotopes;sodium;tantalum 182;zinc 65
R&D Category: Safety aspects
display the document: 34086284.pdf
Comparative study of various methods of cover gas monitoring at KNK II Vergleichende Studie verschiedener Methoden zur Schutzgas-Ueberwachung von KNK II
Hossein, H.SKernforschungszentrum Karlsruhe GmbH (Germany)
KFK-PSB--01.02.17P56A - German - 1987
Abstract: The cover gas monitoring systems in KNK II described in this paper are based on the measurement of fission gases in the primary cover gas. After an introduction, the various components of the cover gas monitoring system are described, including the cover gas control system, the grab sampling system and the experimental failed fuel detection system. Later, some operational results of the cover gas control system and failed fuel detection system are presented and discussed. At the end as a conclusion the main advantages and disadvantages of each system are mentioned
Key words: cover gas;failed element detection;fission products;knk-2 reactor;monitoring;reactor safety
R&D Category: -Failure detection
display the document: 34086285.pdf
Experience with sodium aerosols and accompanying cover gas surveillance at KNK II. Presentation at the meeting on Experience exchange on operational experience of fast breeder reactors, Karlsruhe/Bensberg/Kalkar, June 18. - 22. 1990 Erfahrungen mit Natriumaerosolen und begleitender Schutzgasueberwachung an der KNK II. Praesentation auf der Tagung zu Erfahrungsaustausch ueber Betriebserfahrungen Schneller Brutreaktoren, Karlsruhe/Bensberg/Kalkar, Juni 18. - 22. 1990
Stade, K.ChKernkraftwerk-Betriebsgesellschaft mbH (Germany)
INIS-DE-KBG--018 - German - 1990
Abstract: One problem linked with the operation of sodium cooled reactors is the formation of aerosols in the cover gas and their deposition on colder structural components. At the sodium cooled fast reactor KNK this phenomenon lead to some mobility problems of the rotating plug and of the control rod drives. These effects and counter measures for their removal are discussed in this presentation
Key words: aerosols;control rod drives;cover gas;deposition;knk-2 reactor;reactor monitoring systems;reactor operation
R&D Category: any or undefined
display the document: 34087486.pdf