Nuclear power reactors, heavy-water

This appendix provides additional materials (schematics, layouts, T—s diagrams, basic parameters, and photos) on advanced thermal (combined cycle and supercritical pressure Rankine steam turbine cycle) power plants and nuclear power plants with modern nuclear power reactors [pressurized water reactors (PWRs), boiling water reactors (BWRs), pressurized heavy water reactors (PHWRs), advanced gas-cooled reactors (AGRs), gas-cooled reactors (OCRs), light water-cooled graphitemoderated reactors (LGRs) (RBMKs and EGPs), and liquid metal fast-breeder reactors (LMFBRs) (BN-600 and BN-800)]. 

One of the most significant sources of change in isotope ratios is caused by the small mass differences between isotopes and their effects on the physical properties of elements and compounds. For example, ordinary water (mostly Ej O) has a lower density, lower boiling point, and higher vapor pressure than does heavy water (mostly H2 0). Other major changes can occur through exchange processes. Such physical and kinetic differences lead to natural local fractionation of isotopes. Artificial fractionation (enrichment or depletion) of uranium isotopes is the basis for construction of atomic bombs, nuclear power reactors, and depleted uranium weapons. 

There are various types of nuclear power reactors, including boiling water reactors (BWR) and pressurized water reactors (PLWR or LWR), which are both light-water reactor (LWR) designs and are cooled and moderated by water. There also are pressurized heavy-water reactor (PHWR or HWR) designs. 

All over the world, 432 nuclear power reactors are under operation and more than 36 GW of electricity could be produced as of December 31, 2001. There are several types of reactors such as boiling water reactor (BWR), pressurized water reactor (PWR), Canada deuterium uranium (CANDU), and others. In these reactors, light water is normally used not only as a coolant, but also as a moderator. On the contrary, in CANDU reactors, heavy water is taken. It is widely known that the quality control of coolant water, the so-called water chemistry, is inevitably important for keeping the integrity of the plant. 

Boiler tubes are often cleaned with EDTA or NTA solutions to remove both CaC03 scale and corrosion products. In pressurized heavy water nuclear power reactors, radioactive corrosion deposits (in effect, magnetite in which some of the Fe has been replaced by radioactive Co ) can be removed from the coolant water circuits with an aqueous mixtiu e of oxalic and citric acids (both good chelators for Fe " ") and EDTA. In home laundry operations, bloodstains on clothing can be removed by treatment with oxalic acid, which takes up the iron from the hemoglobin (Section 8.2) as Fe(ox)3 . By the same token, oxalates axe toxic when taken internally, as are many other complexing agents. For example, EDTA is used as a means... 

Nuclear reactors use the heat from a controlled nuclear fission reaction to produce power. The three important types of reactors are light water reactors, heavy water reactors, and breeder reactors. 

This order applies to all varieties of reactors including, but not limited to light water moderated reactors, heavy water moderated reactors, liquid metal cooled reactors, gas cooled reactors and short-pulse transient reactors. Space reactor power and propulsion systems and critical facilities require special design criteria. Attachment 4 is reserved for Nuclear Safety Design for critical facilities and space reactors. 

As a member of the CANDU family, the CANDU 300 design closely follows that of the larger CANDU 600 and CANDU 950 nuclear power plants and is is illustrated in Figure A key CANDU features include a pressure tube reactor, heavy water (D2O) moderator, natural uranium fuel, and on-power refuelling. 

Nuclear reactors use the heat from a controlled nuclear fission reaction to produce power. Fission is controlled, in part, by moderators— materials that fimit the speed of liberated neutrons but that do not themselves undergo fission when bombarded with neutrons. The three important types of reactors are light water reactors, heavy water reactors, and breeder reactors. Breeder reactors produce more fissionable material than they consume. 

Following a general survey of the basic types of nuclear power reactor, separate chapters are devoted to each of the principal designs—the gas-cooled graphite-moderated reactor, the light-water-moderated reactor, the heavy-water-moderated reactor, and the fast reactor. Each chapter includes a discussion of the evolution of the design and a detailed description of one or more typical power plants. 

This report provides the presented papers and summarizes the discussions at an IAEA Technical Committee Meeting (TCM) on Natural Circulation Data and Methods for Innovative Nuclear Power Plant Design. While the planned scope of the TCM involved all types of reactor designs (light water reactors, heavy water reactors, gas-cooled reactors and liquid metal-cooled reactors), the meeting participants and papers addressed only light water reactors (LWRs) and heavy water reactors (HWRs). Furthermore, the papers and discussion addressed both evolutionary and innovative water cooled reactors, as defined by the IAEA. ... 

The next presentations discussed chemical problems encountered in the nuclear power industry. S. R. Hatcher (Atomic Energy of Canada Ltd., Pinawa) gave a general review covering the chemistry of established and novel nuclear fuels, heavy-water production, and reactor operation. 

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