Challenges of ship propulsion systems during DP operations

Ship propulsion configurations with dynamic positioning systems are commonly used as diesel-electric. In particular, situations for ship transfer on longer distances may be used conventional mechanical propulsion system with controllable pitch propeller. Combination of mechanical and electric propulsion system called hybrid propulsion is met as well, where the thrusters of DP systems are driven through the gear by mechanical engine or electric motor independent or both. For the sake of the necessity of limitation of total installed power on the ship may occurred problems with power distribution between the ship propulsion and industry part. It will especially concern those situations when we need to keep power supply to the industry part and there is a necessity to increase the power delivered to ship propulsion part for the purpose of keeping the ship position or heading. The primary task of power management system (PMS) is blackout prevention in ship energetic network and so power distribution to overcome critical conditions of it. Temporarily it may occur the worsening of positioning operation accuracy without any critical situations of industry part. The possibility of momentary overloading of energetic network is primary condition of safety. The critical duration of overloading is one minute. This is indispensable time for increasing the accessible power in the energetic system through switching on the next genset to work. It is a necessity of quick analysis in critical conditions to value what key-actions ought to do in the aim of overcoming emergency situations. The next one is a usage of energy storage devices. It is possible through AC/DC conversion. It was tried to find solutions of equalization the load of gensets to the ship electric energy demand

Possibilities of improving safety and reliability of ship propulsion system during dp operations

Improving safety and reliability of ship propulsion system during dynamic positioning (DP) operations of multipurpose vessels is an essential advantage. It may be such possibilities obtained by application the considered solutions of propulsion systems and all other elements of energetic system. The minimum requirements were determined by creating the regulations of dynamic positioning systems and their levels. Applying the solutions, which were exceeded the limits of basic requirements, allows to increase the safety and reliability levels with a low rise the investment costs. Many marine companies try to invent so low cost solutions. An example analysed in the paper is the Wartsila LCC system. The applications of more complicated solutions in comparison to required duplicated systems are expensive. The cheaper solution is an investing in the development of automatics configurations (for those systems it was applied the triple and quadruple configurations) which in transient or emergency conditions may obtain the time delay making possible a support of industry part work and DP systems. In emergency situation, after the loss of position by DP system, the power management system allow the safe break of work the industry part and return to work after elimination the critical condition

Перспективные сорбенты при обращении с жидкими радиоактивными отходами и дезактивации водных растворов глинисто-солевых шламов ОАО "Беларуськалий"

Глинисто-солевые шламы, относящиеся к отходам производства ОАО «Беларуськалий», были испытаны как недорогой, экологически чистый потенциальный сорбент для удаления радионуклидов из водных растворов и могут быть одним из компонентов цементного наполнителя контейнеров, используемых для хранения радиоактивных отходов. Эффективность сорбционного удаления цезия (I) -137, стронция (II) -90, европия (III) -152 и америция (IV) -241 была исследована в отношении времени фазового уравновешивания, pH, дозы сорбента, и присутствием солей и комплексообразующих агентов. Также было изучено облучение материала. Было установлено, что поглощение радионуклидов практически завершено. Предложена также технология удаления технеция-99 из водного раствора

Clay-salt slimes of the JSC ‘‘Belaruskali’’ as potential engineering barriers in the radioactive waste repositories: sorption of Cs(I), Sr(II), Eu(III) and Am(III)

В статье представлены результаты сорбции цезия (I), стронция (II), европия (III) и ионов америция (III) на алюмосиликатах, отделенных от шламов кизолита в зависимости от времени контакта, рН, концентрации исходного металла

68Ge/68Ga radioisotope generator as a source of radiotracers for water flow investigations

Radiotracer experiments on the model of rectangular settler with a volume of 3 m3, with a consecutive application as a tracer of the aqueous phase fluoresceine (representative tracer of water), eluate from a 68Ge/68Ga radioisotope generator (0.1 N HCl solution) and chelates after Ga ions complexation with 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) and 1,4,7,10-tetrazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) were carried out. The obtained residence time distribution (RTD) functions indicate that only the complex compounds of gallium are stable in the water phase and are not adsorb on the vessel walls, so they can be recommended as tracers of the water phase

Перспективные сорбенты при обращении с жидкими радиоактивными отходами и дезактивации водных растворов глинисто-солевых шламов ОАО «Беларуськалий» / Л. Фукс, Л. Москальчук, И. Хердзик-Конечко

Окружающая среда природных и урбанизированных территорийClay-salt slimes, production wastes from the JSC “Belaruskali”, have been tested as a low-cost, eco-friendly potential sorbent for the removal of radionuclides from aqueous solutions, and may be a component of the cement filling of drums used in the storage of radioactive wastes. The efficiency of sorptive removal of caesium (I) -137, strontium (II) -90, europium (III) -152, and americium (IV) -241 was examined with respect to the time of phase equilibration, pH, sorbent dosage, and the presence of salts and complexing agents. Irradiation stability of the material was also studied. It was found that uptake of the radionuclides is almost complete. A procedure for the removal of technetium-99 has been also proposed. Experimental results obtained within the presented work confirm our expectations.Глинисто-солевые шламы, относящиеся к отходам производства ОАО «Беларуськалий», были испытаны как недорогой, экологически чистый потенциальный сорбент для удаления радионуклидов из водных растворов и могут быть одним из компонентов цементного наполнителя контейнеров, используемых для хранения радиоактивных отходов. Эффективность сорбционного удаления цезия (I) -137, стронция (II) -90, европия (III) -152 и америция (IV) -241 была исследована в отношении времени фазового уравновешивания, pH, дозы сорбента, и присутствием солей и комплексообразующих агентов. Также было изучено облучение материала. Было установлено, что поглощение радионуклидов практически завершено. Предложена также технология удаления технеция-99 из водного раствора. Экспериментальные результаты, полученные в рамках представленной работы, подтверждают наши предположения по данному исследованию

Isotope effects of gallium and indium in cation exchange chromatography

The isotope effects of gallium (69/71Ga) and indium (113/115In) have been determined in the system: strong cation exchanger (Dowex 50-X8)/HCl. The sings of gallium and indium effects were opposite, i.e., the heavier isotope of gallium was fractionated into the resin phase, while the heavy isotope of indium was fractionated into the liquid phase. The values of unit separation gains were found to be +3.0 ´ 10-5 for gallium and –2.0 ´ 10-4 for indium. A possible explanation of the effects is proposed

Extraction of uranium from low - grade Polish ores : dictyonemic shales and sandstones

Leaching studies were performed to develop a suitable method for extraction of uranium from domestic uranium ores: dictyonemic shales and sandstones. The extracting procedure was composed of successive separation steps: crushing and grinding, acid or alkaline leaching, solid-liquid separation, and inductively coupled plasma mass spectrometry (ICP-MS) analyses of post-leaching solutions. The influence of such process parameters as temperature, pressure, particle size of solid material, kind of leaching solution and its concentration, on the recovery efficiency of uranium and accompanying metals were tested. The efficiency of uranium leaching with sulphuric acid solution achieved 81%. Satisfactory results were obtained for the alkaline leaching process. It was found that uranium can be selectively extracted by the alkaline leaching solution. Almost complete extraction of uranium from sandstones was achieved when a mixture of sodium carbonate and sodium hydroxide, with hydrogen peroxide as a leaching solution was used

Ion exchange investigation for recovery of uranium from acidic pregnant leach solutions

The article describes studies on the separation of uranium from acid pregnant leach solutions obtained from Polish uranium ores: dictyonema shales and sandstone rocks. Ion exchange chromatography was applied for uranium sorption, using commercially available, strongly basic anion exchanger, Dowex 1. In model experiments, the influence of degree of crosslinking of Dowex 1 on the efficiency of uranium extraction was investigated. The effect of H2SO4 concentration on the breakthrough curve of uranyl ions for the Dowex 1 resins, of different crosslinking: X4, X8 and X10, was examined. Unexpectedly high increase of exchange capacity of uranium was observed in case of Dowex 1X10. This gives potential opportunity of improving the effectiveness of uranium recovery process. Applying column packed with Dowex 1X10, ‘yellow cake’ with ca. 92% yield and high purity of recovered uranium was obtained. A block diagram of the procedure for uranium and lanthanides extraction from acidic leach liquor has been proposed