Maria Naidin e-mail: maria.naidin@mycampus.uoit.ca Sarah Mokry e-mail: sarah.mokry@mycampus.uoit.ca Farina Baig e-mail: farina.baig@gmail.com Yevgeniy Gospodinov e-mail: yevgeniy.uoit@gmail.com Faculty of Energy Systems and Nuclear Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1K 7K4, Canada Udo Zirn Hitachi Power Systems America, Ltd., 645 Martinsville Road, Basking Ridge, NJ 07920 e-mail: udo.zirn@hal.hitachi.com Igor Pioro Faculty of Energy Systems and Nuclear Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1K 7K4, Canada e-mail: igor.pioro@uoit.ca Greg Naterer Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1K 7K4, Canada e-mail: greg.naterer@uoit.ca Thermal-Design Options for Pressure-Channel SCWRS With Cogeneration of Hydrogen Currently there are a number of Generation IV supercritical water-cooled nuclear reac- tor (SCWR) concepts under development worldwide. The main objectives for developing and utilizing SCWRs are (1) to increase the gross thermal efﬁciency of current nuclear power plants (NPPs) from 33–35% to approximately 45–50% and (2) to decrease the capital and operational costs and, in doing so, decrease electrical-energy costs (approxi- mately US$ 1000 / kW or even less). SCW NPPs will have much higher operating param- eters compared to current NPPs (i.e., pressures of about 25 MPa and outlet temperatures of up to 625° C). Additionally, SCWRs will have a simpliﬁed ﬂow circuit in which steam generators, steam dryers, steam separators, etc. will be eliminated. Furthermore, SCWRs operating at higher temperatures can facilitate an economical cogeneration of hydrogen through thermochemical cycles (particularly, the copper-chlorine cycle) or direct high- temperature electrolysis. To decrease signiﬁcantly the development costs of a SCW NPP and to increase its reliability, it should be determined whether SCW NPPs can be de- signed with a steam-cycle arrangement that closely matches that of mature supercritical (SC) fossil power plants (including their SC turbine technology). On this basis, several conceptual steam-cycle arrangements of pressure-channel SCWRs, their corresponding T-s diagrams and steam-cycle thermal efﬁciencies are presented in this paper together with major parameters of the copper-chlorine cycle for the cogeneration of hydrogen. Also, bulk-ﬂuid temperature and thermophysical properties proﬁles were calculated for a nonuniform cosine axial heat-ﬂux distribution along a generic SCWR fuel channel, for reference purposes. DOI: 10.1115/1.2983016 1 Introduction Prior to a discussion of the conceptual steam-cycle arrange- ments of a SCW NPP, it is important to describe the general fea- tures of the various types of SCWRs that are currently investi- gated. This section also includes a review of the modern SC turbines and their parameters to ensure that current technology can match the pressure and temperature parameters proposed. 1.1 SCWR Concepts. Currently there are a number of Gen- eration IV SCWR concepts under development worldwide 1. The main objectives for developing and utilizing SCWRs are 1 to increase the thermal efﬁciency of current NPPs from 33–35% to approximately 45–50% and 2 to decrease the capital and op- erational costs and, in doing so, decrease electrical-energy costs approximately US$ 1000 / kW or even less. SCW NPPs will have much higher operating parameters com- pared to current NPPs i.e., pressures of about 25 MPa and outlet temperatures of up to 625°Cfor details, see Fig. 1. Addition- ally, SCWRs will have a simpliﬁed ﬂow circuit in which steam generators, steam dryers, steam separators, etc. will be eliminated. Furthermore, SCWRs operating at higher temperatures can facili- tate an economical production of hydrogen through thermochemi- cal cycles or direct high-temperature electrolysis. The SCWR concepts 1 follow two main types: a a large reactor pressure vessel PV with a wall thickness of about 0.5 m to contain the reactor core fueled heat source, analogous to con- ventional LWRs or b distributed pressure channels PChs or tubes analogous to conventional heavy water reactors HWRs. Within those two main classes PV and PCh1, pressure- channel reactors are designed to be more ﬂexible to ﬂow, ﬂux, and density changes than the PV reactors. This makes it possible to use the experimentally conﬁrmed better solutions developed for these reactors. The main ones are fuel reloadings and channel- speciﬁc ﬂow-rate adjustments or regulations. A design whose ba- sic element is a channel or tube, which carries a high pressure, has an inherent advantage of greater safety than large vessel structures at supercritical SC pressures. For reference purposes, the bulk- ﬂuid temperature and thermophysical properties proﬁles in a ge- neric PCh SCWR fuel channel can be found in the Appendix. Atomic Energy of Canada Limited AECL and the Research and Development Institute of Power Engineering RDIPE or NI- KIET in Russian abbreviations1,3 are currently developing concepts of the PCh SCWRs see Table 1. Table 2 lists the criti- cal parameters of water. Manuscript received June 17, 2008; ﬁnal manuscript received June 23, 2008; published online October 1, 2008. Review conducted by Dilip R. Ballal. Paper pre- sented at the 16th International Conference on Nuclear Engineering ICONE16, Orlando, FL, May 12–15, 2008. Journal of Engineering for Gas Turbines and Power JANUARY 2009, Vol. 131 / 012901-1 Copyright © 2009 by ASME Downloaded 18 Oct 2008 to 192.197.54.20. Redistribution subject to ASME license or copyright; see http://www.asme.org/terms/Terms_Use.cfm