Jerzy A. SawickiUniversity of Victoria | UVIC · Department of Mechanical Engineering
Jerzy A. Sawicki
MSc, PhD, dr hab.
I am continuing research in zirconium alloys, corrosion and meteorites with Mossbauer spectroscopy and other methods.
About
308
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Introduction
Development and applications of Mössbauer spectroscopy and other experimental techniques in atomic energy research, corrosion, minerals and catalysis, in the Institute of Physics, the Jagiellonian University in Cracow, Poland, and as a guest scientist in several European universities and nuclear institutes. From 1984 till 2004 with AECL Chalk River Laboratories, Ontario, Canada. Presently collaborates with colleagues in Department of Engineering, University of Victoria, British Columbia, Canada
Additional affiliations
October 2005 - December 2018
Position
- volunteer
Description
- Mossbauer spectroscopy laboratory, giving talks, attending meetings, consulting students
January 2005 - December 2018
Interatomics
Position
- Principal Investigator
October 1986 - October 2004
Position
- Senior Research Scientist SE5, permanent position
Description
- Development and applications of Nuclear Reaction Analysis, Mossbauer spectroscopy and other nuclear techniques for studies of thermonuclear fusion, tritium in materials, corrosion in nuclear reactors, reactor zirconium alloys, catalysts and minerals.
Education
March 1964 - December 1966
Joint Institute for Nuclear Research, Laboratory of Neutron Physics
Field of study
- Mossbauer spectroscopy of 57Fe and 67Zn at low temperatures
September 1962 - July 1974
Jagiellonian University, Institute of Physics
Field of study
- nuclear and solid state physics
Publications
Publications (308)
The concept of disposal of nuclear fuel waste in crystalline rock requires the effects of microbial action to be investigated. The Underground Research Laboratory excavated in a pluton of the Canadian Shield provides a unique opportunity to study these effects. Three biofilms kept moist by seepage through fractures in granitic rock faces of the Und...
The samples of crud removed from the surface of fuel rods and corrosion products sampled by filtration of condensate and feed water in three boiling water reactors (BWR) operating at normal water chemistry (NWC) were analyzed using 57Fe Mössbauer spectroscopy. The corrosion products concentration and phase composition was examined in filter membran...
This paper describes the characteristics of corrosion product deposits found in upper regions of high axial offset anomaly (AOA) once-burnt fuel assemblies after Cycle 9 in the Callaway pressurized water reactor (PWR). The ∼100-μm-thick deposits consisted of a new type of highly porous and structured Ni-, Fe-, B-, and Zr-rich material. The analyses...
The role of microorganisms in the deposition of banded iron-formations (BIF) has been discussed for many years, as it has been difficult to explain the accumulation of iron and silica in these deposits by chemical processes alone. In this paper, we survey the significance of the presence of microorganisms in microfossils and stromatolites associate...
The abundance of 57Fe isotope in nuclear reactor core materials can be considerably enriched by neutron-capture 56Fe(n,γ) reactions. This is demonstrated using the sections of Zr-2.5Nb pressure tubes removed from two CANDU* reactors. The tubes contained 0.11 and 0.04 wt% Fe and were irradiated for about 10 effective full power years (EFPY) up to 10...
The panels of high chromium steel (A1010), high-performance steel (HPS 70W) and weathering steel (WS) were exposed to accelerated salt-spray corrosion test for 1 week and to less aggressive test for additional 13 weeks. After the tests, the corrosion products formed were extracted layer after layer and examined as a function of their depth with Mös...
Paper reports Raman micro-spectroscopy analyses of hexagonal H3 diamond (lonsdaleite) in the unusual meteorite-like rock found in Sooke Basin on Vancouver Island, in British Columbia. The nanoparticles of lonsdaleite are surrounded by clinopyroxene clasts (diopside and augite). The Raman bands E2g, A1g and E1g of lonsdaleite are very well defined a...
Electron microscopy and Raman spectroscopy analyses of selected areas in polished surface of Sooke rock meteorite-like find are presented and discussed. The compositions of diopside-pyroxene and olivine-forsterite clasts have been determined. Raman spectroscopy of carbonaceous fossil-like areas indicated very well defined subbands E2g, A1g and E1g...
This is Presentation 31531, at Session F3.2, Astrobiology.
The in situ Raman spectroscopy analyses of carbonaceous fossils in the Sooke #1 meteorite find are presented and discussed. The Raman spectra and maps reveal nanodiamondized particles of lonsdaleite surrounded by silicates of pyroxene-diopside structure. The three active Raman modes E2g, A...
In the rock found in Sooke Basin on Vancouver Island we discovered some carbonaceous fossils containing lonsdaleite particles that could be only formed during gigantic impact shocks in meteorites or their impact craters. We examined Raman spectra and maps of these objects and discuss them in comparison with the spectra of carbonaceous matter in met...
A very intriguing 13-kg oriented stone with 70% of surface covered with black fusion crust and some magnetic properties was discovered near Juan de Fuca Strait, in British Columbia. Our first geochemical, petrological, X-ray diffraction, Raman, Mössbauer and oxygen isotopic analyses suggest that it could be an ungrouped primitive achondrite of poly...
A very intriguing 13 kg oriented stone with magnetic properties and ~70% of surface covered with black fusion crust was discovered recently near Juan de Fuca Strait, in British Columbia. Our previous geochemical, petrological, X-ray diffraction, Raman, Mössbauer and oxygen isotopic analyses [1], [2] suggest that it could be an ungrouped primitive a...
Mossbauer spectroscopy was used to further investigate a new unusual chondrite-like find from Sooke Basin in Vancouver Island, in British Columbia. The main iron minerals identified in it are magnetite and nano-phase iron particles, as well as olivine-fayalite and pyroxene-diopside with iron. Observed considerable depth dependence of their fraction...
In our paper #6005 to be presented at this conference we have reported our first Raman analyses of 13-kg Sooke #1 find in Sooke Basin near Juan de Fuca Strait. Having an opportunity of examining more samples from this unusually large object, here we report on the heat-affected transformation of Fe-bearing minerals in it as observed by Mössbauer tra...
The results of examinations of chondrite-like find in Sooke Basin with chemical and oxygen isotope techniques, petrography, X-ray diffraction, Mossbauer and Raman spectroscopies are presented and discussed.
There is a typo in Fig. 1: not 20 mm long, but 2 mm long
The properties of Fe additions in Zr-2.5Nb pressure tube alloy are investigated after plastic deformations, heat treatments below its monotectoid temperature and severe radiation damage by neutrons and ions. Mössbauer spectra showed that in the β-quenched and hot-extruded Zr-2.5Nb about 80% of Fe atoms is located in βZr and the reminder in a metast...
The abundance of 57Fe isotope in nuclear reactor core materials can be considerably enriched by neutron-capture 56Fe(n,γ) reactions. This is demonstrated using the sections of Zr-2.5 wt.%Nb pressure tubes removed from two CANDU* reactors. The tubes contained 0.11 and 0.04wt% Fe and were irradiated for about 10 effective full power years (EFPY) up t...
This is the status report of work performed as part of Chalk River neutrino mass measurements project in the 1980's. Ultra-thin tritium sources for the electron anti-neutrino mass measurements and several dummy deuterium targets were studied by elastic recoil detection (ERD) under 4He bombardment and by the T(d,a)n reaction at forward scattering ge...
A technique for active pulse acquisition is used for enhancement of resonant lines and for drastic improvement of the signal-to-noise ratio in conversion electron Mössbauer spectra. It is shown that the measurements of the Mössbauer spectra in the active pulse acquisition mode can be remarkably shortened in comparison with the conventional passive...
The properties of cold-worked Zr-2.5Nb pressure tubes used in CANDU™ reactors, such as resistance to corrosion and deformation during service, are dependent on the form and distribution of ~0.1 wt% Fe in their microstructure. Mössbauer spectroscopy analyses of offcuts from such tubes indicate Fe atoms in both Nb enriched β-Zr (β enr) and t-Zr2Fe pr...
Conclusions: The obtained results prove that the bonaccordite needles formed on the surface of fuel pins in some of PWRs are crystalline and that their electron diffraction patterns are in accord with reported crystallographic features of mineral bonaccordite. The examined particles remained crystalline at fast neutron fluencies at least up to 1024...
The hydrothermal synthesis of a nickel–iron oxyborate, Ni2FeBO5, known as bonaccordite, was investigated at pressures and temperatures that might occur at the surface of high-power fuel rods in PWR cores and in supercritical water reactors, especially during localized departures from nucleate boiling and dry-outs. The tests were performed using aqu...
Secondary side corrosion products (sludge) collected during one of CANDU* reactor startups from wet layup have been examined by X-ray fluorescence and Mössbauer spectroscopy. The transport and chemical form of iron oxides and oxyhydroxides were determined in condensate, feedwater and preheater outlet as a function of temperature and time. The sludg...
Mössbauer spectroscopy of 73.0 keV gamma-ray transition in 193Ir and supplementary analytical techniques were used to study the microstructure and chemical form of polymer-supported hydrophobic bimetallic Pt–Ir catalysts for detection and removal of CO from humid air at ambient conditions. The catalysts, typically with a composition of 9 wt.% Pt an...
To assess the influence of boron iron compounds deposited on fuel rods on unexpected power shifts in pressurized water reactors, samples of crud scrapes retrieved during refuelling from three reactor cores were analyzed using 57Fe Mössbauer spectroscopy. The fuel crud scrapes were found to contain predominately nickel–iron ferrite NixFe3−xO4 in a c...
Weathering steel is used almost exclusively by Ministry of Transportation Ontario (MTO) for construction of steel bridges since 1968. This steel, under normal weathering cycles, oxidises to form a tough layer of rust or 'patina', which protects the steel from unabated corrosion. Although many of these bridges are exhibiting stable patina in most of...
An experimental set up, simulating the secondary side feedwater (FW) train of a pressurized water reactor (PWR), has been built at Studsvik Nuclear AB. Laboratory experiments were performed in order to study corrosion product transport, corrosion potentials of different materials, as well as oxygen consumption. Particulate iron was added to the wat...
Our research and development focuses on improving the efficiency of electric power systems and other complex industrial systems, and on avoiding harmful environmental effects. Selected highlights of following projects are presented: 1. Examination of corrosion products formation, transport and deposition along water cooling systems aiming at corros...
Experiences of work in support of development, operation and maintenance of nuclear power reactor systems will be briefly summarized. Examples will include the studies of corrosion of system components, corrosion product transport and redeposition, investigation of unirradiated and irradiated zirconium alloys, and applications in nuclear waste stor...
Ministry of Transportation Ontario has been using weathering steel for bridge girders since 1968. The main advantage of using weathering steel is that, under normal weathering cycles, it will form a tough outer oxide layer referred to as ‘patina’ that will protect the steel from unabated corrosion. However, recently the ministry has observed that t...
An experimental set up, simulating the secondary side feedwater train of a pressurized water reactor (PWR), has previously been designed and built at Studsvik Nuclear AB. The overall purpose of our research program is to optimize feedwater chemistry in order to reduce the usage of hydrazine and to decrease the transport of oxidized iron species to...
The particulate and ionic species of metals in cooling and moderating water bear a wealth of information about interaction of water with components of power plants, the information that - if properly gathered and understood - can be more beneficial for maintenance, longevity and cost effectiveness of plants that it is at present. The main results f...
The article written on the occasion of the 80th birthday of Prof. Hendrik de Waard and work with him and his group in his excellent laboratory in Groningen.
This is a report, Atomic Energy of Canada Limited, Chalk River Laboratories, AECL Ref. #100423-0044
Characterization of corrosion product deposits extracted after the end of Cycle 9 (EOC9) from the Callaway core, performed at AECL, and reported in EPRI Report 1003129 has shown that Ni-Fe borate (Ni2FeBO5), mineral name bonaccordite) was a major co...
Laboratory experiments were performed in order to study corrosion product transport, corrosion potential of steam generator materials and potential of platinum electrode, as well as oxygen consumption in a secondary-side feedwater train of a pressurized water reactor (PWR). The experimental set-up used was designed to simulate, as closely as possib...
This technical note reports the first use of cationic ion-exchange (IX) filter membranes for the sampling of soluble metal species in CANDU heat transport system (HTS) fluid. Particulate and IX membranes in series were exposed to HTS fluid from the sampling lines on the outlet headers in the North and South loops of Darlington Units 1 to 4 on 3003...
The molecular structure and properties of a low-dimensional nickel-iron borate, Ni2FeBO5, will be reviewed. The solid, extremely rare in nature as mineral, was recently discovered during analysis in Chalk River of crud deposits removed from first-load fuel rods in a high-boiling duty Callaway PWR. Various analyses and properties of these deposits w...
An experimental set up, simulating the secondary side feedwater (FW) train of a pressurized water reactor (PWR), has been built at Studsvik Nuclear AB. Laboratory experiments were performed in order to study corrosion product transport, corrosion potentials of different materials, as well as oxygen consumption. Particulate iron was added to the wat...
This report documents the ongoing examination of corrosion-product transport (CPT) in the heat transport system (HTS) of Darlington Units 1, 2, 3 and 4, before and after the transition to the lithium-controlled range of 99-10.2 pHa. The corrosion products were collected on 0.45-um-pore-size membranes by integrated sampling of heavy water coolant, w...
Fuel crud deposits on Callaway Cycle 9 once-burnt high-axial offset anomaly (AOA ~ -15%) feed assemblies revealed a complex 4-phase matted-layered morphology of a new type that is uncommon in pressurized water reactors [1-3]. The up to 140-μm-thick crud flakes consisted predominantly of insoluble needle-like particles of Ni-Fe oxyborate Ni2FeBO5 (b...
Recent EPRI-sponsored work* on analysis of fuel crud from selected BWR and PWR cores has provided new insights on the complex solid-state nature of hydrothermally-formed precipitates and their activation in the nuclear reactor core. The results of this work are briefly reviewed in the context of increasing requirements for water purity in reactor c...
This report documents the results of a study of Callaway Cycle 9 fuel crud at AECL under EPRI contract WP6151-20. Samples of fuel crud scrapes from span 6A of two high AOA feed assemblies were examined using a variety of techniques. The crud consisted of a new type of highly structured, Ni, Fe, B, and Zr-rich morphology. The methodology for charact...
Corrosion products (crud) transport in CANDU reactors is linked to the degradation of their heat transport system (HTS), especially due to flow-assisted corrosion (FAC) of outlet feeders (thinning), IG SG tube fouling (power derating), and activity transport (radiation dose). Our earlier work at Darlington Units showed that crud (Fe oxides) transpo...
Axial offset anomaly (AOA) in pressurised water reactors (PWRs) is a larger than expected negative flux depression beginning approximately at 5000 MWd/MtU feed fuel burnup. AOA can threaten the full power shutdown margin and thereby force a costly derate. More than 20 US cores have exhibited AOA, one seriously enough to have derated to 70% power fo...
The fuel crud from Callaway EOC9 high-AOA feed assemblies reveals a complex 4-phase morphology. It contains Ni-Fe oxyborate Ni2FeBO5 (bonaccordite); nickel oxide NiO (bunsenite); monoclinic zirconia m-ZrO2 (baddeleyite); and a small fraction of nickel ferrite NiFe2O4 (trevorite). The presence of bonaccordite and zirconia precipitates indicates alka...
Startup crud bursts are the primary source of steam generator secondary side fouling in stations practising good operating chemistry. It has been suspected that layup practice has a significant impact on the size of the crud bursts. The present study shows that the generation and transport of crud, the fraction of unreduced iron oxides, and the rat...
The presentation summarizes the results of the Callaway Cycle 9 Span 6A fuel crud study performed at AECL under EPRI WP6151-20 contract, in collaboration with Westinghouse and AmerenUE Callaway Plant. Samples of span 6A fuel crud scrapes from two Callaway EOC9 high AOA feed assemblies have been examined using a variety of techniques. The crud indic...
A versatile laboratory system was constructed to simulate corrosion product transport and redox potentials in a secondary-side feedwater train of pressurized-water reactors, and - especially - the effects of oxygen and hydrazine on oxidation state of suspended iron oxides. The present tests were performed to reproduce feedwater conditions at Ringha...
As an extension of the presentation given at joint session of Working Groups 1, 2 & 4, the most recent results obtained at AECL are here presented and discussed in some detail. The methodology of characterization of complex 4-component crud has been further developed. The optical metallographic and high-resolution electron microscopic images are pr...
The current work at AECL on robust fuel crud characterization (under EPRI contract WO6151-20) is briefly summarized. The study is performed in collaboration with Westinghouse and AmerenUE Callaway Plant. Samples of span 6A fuel crud scrapes from two Callaway EOC9 high-AOA feed assemblies are being examined using a variety of techniques. The crud in...
Introduction Project and samples Experimental methods Review of results Bonaccordite surprise Zirconia surprise More about 4-component crud Discussion Interim conclusions
A versatile laboratory system was constructed to simulate corrosion product transport and redox potentials in a secondary-side feedwater train of pressurized-water reactors, and - especially - the effects of oxygen and hydrazine on oxidation state of suspended iron oxides. The water was preheated up to 130oC using a stainless steel heater, and then...
Startup crud bursts are the primary source of steam generator secondary side fouling in stations practising good operating chemistry. It has been suspected that layup practice ha a significant impact on the size of the crud bursts. This report shows that we have the tools to analyze the changing nature of the crud and its transport during startups...
The techniques of X-ray fluorescence and Mossbauer spectroscopy are applied for nondestructive (non-digestive) analysis of solids sampled on particulate filters in water circuits of nuclear generating stations (NGSs). These techniques are applied to study corrosion-product transport and its effects in both reactor steady-state operation and start-u...
Nucleoelectrica Argentina Sociedad Anonima (NASA) has been operating a 600 MW(e) CANDU-6-type pressurized heavy-water reactor since 1993 at the Embalse site. The secondary-water circuit, which was designed by ITALIMPIANTI , does not use a mechanical deaerator - this is an exceptional practice in the family of CANDU power plants. The N2H4 is injecte...
Large amounts of corrosion products (crud) are transported from the boiler feedwater to the steam generators (SG’s) during reactor operation; especially worrisome are bursts of oxidized species that occur during reactor startups (Refs. 1, 2). The goal of this work is to evaluate whether one can predict sludge composition and transport, based on var...
A microbial biofilm consortium enriched from Shield surface water is able to mediate geochemical cycling of iron within a biofilm. Iron can be leached from Fe(II) containing minerals such as magnetite, biotite and ilmenite to generate a colloidal Fe(III) suspension. The Fe(III) can then be reduced back to Fe(II) by iron-reducing bacteria that utili...
Crud transport in electric power systems
Significance of crud; e.g. recent AOA in PWRs
Primary side crud sampling and analysis
Review of results: Darlington, Bruce B, Gentilly-2
pH - crud dependence; link to feeders
Oxidation state of iron; "red" vs. "black" crud
Links to fuelling machine and filter fouling
Conclusions
A two-day workshop on layup, shutdown and startup chemistry optimization in CANDU stations was held on 1999 March 2 and 3 at Ontario Hydro Nuclear, Toronto, Canada. The purpose of this workshop was to exchange information on:
- the impact of transients such as shutdowns, layups and startups on the degradation of steam generators and other reactor w...
A brief survey of preparations for examination of the fuel crud samples retrieved from the Callaway Cycle 9 PWR core affected by Axial Offset Anomaly was given.
Changes in the chemical environment of iron in Zr–V–Fe getters, as a function of hydriding–dehydriding cycles and exposure to impurities, were examined using Mössbauer spectroscopy. Three clearly distinct groups of spectral parameters were observed for unused, hydrided and poisoned getter samples. The nature of the getter-deactivation process is di...
The summary of the presentation and follow-up discussion is given in section 4.3.2, pages 39 and 40 of the Proceedings.
Mössbauer spectroscopy of the 23.9 keV γ-rays in 119Sn nuclei was applied to study Zircaloy-2, Zircaloy-4, and other tin-bearing zirconium-based alloys of interest to nuclear power technology. Zircaloys are extensively used in nuclear reactors as fuel cladding. In CANDU reactors, Zircaloys are also used as major structural components such as caland...
Mössbauer spectroscopy was used to investigate the reactions of microbes with iron minerals in aqueous solutions and as components of rocks in banded iron formations and granite. A microbial biofilm that formed on a wall of an excavated granite vault in a deep underground laboratory initiated this research. At the aerobic face of the biofilm, iron...
Iron oxide and hydroxides can be precipitated from solution with both Fe 2 and Fe 3 states by a microbial consortium enriched from surface water draining a granitic batholith. The Fe 2 /Fe 3 ratio of the microbial precipitate is determined by both the initial environ-ment and subsequent diagenesis. To evaluate the thermal aspects of diagenesis, bio...
A one-day workshop on electrochemical monitoring in PWR and CANDU power plants was held on 1998 June 25 at Ontario HydroTechnologies, Toronto, Canada. The purpose of the workshop was to bring experts, researchers and nuclear plant chemists together to share information on electrochemical potential properties of water cooling systems. The areas cove...
This paper describes the application of X-ray fluorescence (XRF) and Mossbauer spectroscopy (MS) techniques to monitor corrosion-product transport (CPT) in water circuits of nuclear reactors. The combination of XRF and MS techniques was applied in studies of CPT crud filters from both primary-and secondary-side water circuits (i.e. radioactive and...
The major issues currently associated with monitoring and controlling corrosion-product transport in the balance-of-plant and steam generators of CANDU stations are discussed. The discussion is based mostly on the results and observations from Ontario Hydro plants, and their comparisons with PWRs and the EPRI chemistry guidelines. Systematic studie...
Deep beds of low cross-linked ion-exchange resins have been tested as a means of corrosion-product removal from condensate water in boiling-water nuclear reactor (BWR) at Clinton Power Station, Illinois Power Company. The phase composition of iron deposits in two cores extracted at different times from the same used resin bed, and in particulate fi...
The paper reports a corrosion-product transport study in the primary-side of CANDU reactors. The study is based on systematic crud sampling examinations at Darlington NGS. Emphasis is placed on the corrosion-product transport and oxidation state as a monitor of primary water chemistry state, and as a monitor of system corrosion effects. The D2O was...
Topics: 1. Steady-state in CANDU and PWRs, 2. High-hydrazine start-ups, 3. Loop tests with hydrazine.
Review of work was presented on corrosion product transport (CPT) and electrochemical potential (ECP) in steady-state and start-ups with hydrazine, as well as in loop tests. A comparison of oxidation state of dsteady-state corrosion products in CAN...
A one-day seminar on hydrazine minimization and alternative oxygen scavangers and operational actions in CANDU power plant feedwater was held on 1997 October 24 at AECL - Chalk River. The purpose of the seminar was to bring nuclear plant operators, designers and researchers together to share information on hydrazine applications. Emerging issues co...
Oxidized corrosion products transported by feedwater may have a detrimental effect on steam-generator tubing by increasing the probability of intergranular stress-corrosion cracking. The ability of hydrazine additions to reduce oxidized iron species solvated in PWR feedwater to magnetite is, however, not satisfactorily understood.
We have studied...
A microbial consortium enriched from surface water draining the Lac du Bonnet granitic batholith in Manitoba, Canada, was able to mediate the transformation of 11% of the Fe in a sample of magnetite into hematite within three weeks. Holes, up to 100 μm in diameter, were formed in grains of magnetite in a polished section of granite that had been ex...
The major issues currently associated with monitoring and controlling corrosion-product transport in the balance-of-plant and steam generators of CANDU stations are discussed. The discussion is based mostly on the results of tests and observations from Ontario Hydro plants, and their comparisons with PWRs and the EPRI chemistry guidelines. Systemat...
Conversion electron and X-ray backscattering Mössbauer spectroscopy was used to identify iron compounds that were formed on carbon steel in simulated CANDU® reactor coolant containing 15 to 60 ppb (μg/L H2O) soluble zinc. Analyses of the coupons exposed to coolant in the absence of zinc indicated the formation of magnetite, whereas, in the presence...
A study has been performed in a high-temperature, high-pressure experimental loop to examine the effect of zinc addition on carbon steel under CANDU primary heat transport system conditions in coolant unsaturated with respect to iron. Spectroscopic analyses of surfaces exposed to zinc-contatining coolant indicate the presence of zinc ferrite in the...
The phase composition and oxidation state of iron-bering corrosion products extracted from the primary heat-transport system of Darlington NGS, North and South loops of Units 1 to 4 have been studied. Crud transport was sampled at reactor outlet common headers using an integrated crud samplers (with 0.45 μm-sized Millipore filters). During crud dep...
The oxidation state of iron in the all-ferrous secondary circuit of Bruce-B NGS Units 5-8 was investigated during several years at AVT/Hydrazine system chemistry conditions. Particular iron was found to be the predominant constituent of all sample streams; its greatest sources were the two-phase flow areas of the condensers and high-pressure heater...
An overview of work performed in WPIR 2011 was given to correlate operating conditions with the kinds of oxides transported in the plant. A collaboration with Studsvik of Sweden involving testing in a loop showed a clear increase in proportion of magnetite with hydrazine concentration and a corresponding correlation of % magnetite with ECP. Recent...
Mössbauer spectroscopy of 57Fe was used to study the chemical form and distribution of iron in Zircaloy-2 and Zircaloy-4. The spectra of Zircaloy-4 consist of two overlapping quadrupole-split doublets, which can be ascribed to precipitates of the pseudobinary Laves-phase intermetallic compound Zr(Cr,Fe)2, which has a hexagonal MgZn2 (C14) type stru...
Conclusions: This work has contributed towards establishing an inventory of corrosion products in the secondary system of a CANDU reactor. A variety of corrosion products were identified including magnetite, hematite, maghemite, goethite, lepidocrocite and wustite. Very high percentages of magnetite were observed on components exposed to steam, whe...
We have examined the influence of hydrazine operation on the transport and oxidation state of corrosion products in the secondary system at Bruce-B Unit-7 CANDU* reactor. The studies were performed during prolonged steady-state run, as well as outage and following unit start-up. The oxidation states of particulate corrosion products in the condensa...
Questions
Questions (7)
Hello all,
I would greatly appreciate your comments about our abstract and poster #2775 presented at 52 Lunar and Planetary Science Conference held in Houston, in March 15-19 this year.
We presented the first results of our examinations of the unusual achondrite-like find, most likely the meteorite from early watery Mars. We found an unusual 15 mm large fossil in it that according to our preliminary micro-Raman spectroscopy examinations contains carbon in nano-diamond particles characteristic for meteorites exposed to huge impact shocks. This and our other data so far are - in our understanding so unusual - that they should deserve more interest from scientific community. In fact, Is it possible that this find contains the long searched for traces of extraterrestrial early life?
Would anybody be interested in helping us to answer this question?
Jerzy (George) Sawicki
Victoria, BC, Canada
