Session: 02-08: Balance of Plant

Paper Number: 64473

Start Time: August 6, 2021, 03:15 PM

64473 - Conceptual Design of Nuclear Wet Steam Turbines for Ease of Mass Manufacture 

Rapid decarbonisation of the world energy system appears necessary to avoid dangerous levels of climate change, and this position has now been codified through international accords such as the Paris Agreement.

If nuclear power is to play a large role in the decarbonisation of the world energy system, unprecedented rates of nuclear construction must be achieved. Designs must be tailored to ensure ease of mass manufacture using available plant and labour resources.

Modern nuclear steam turbines contain very large numbers of heat exchangers, including in the feedwater heating system and in the condenser system. Large heat exchangers are often laborious and time consuming to construct and represent a significant expense, especially if a large fleet of units must be constructed in a short period of time.

However, many of these heat exchangers can be eliminated by the use of alternative turbine flowsheets, for example through the use of direct contact condensers and direct contact feedwater heaters. These technologies have been used extensively and succesfully in the power generation field, and their application to a modern wet steam turbine system represents an opportunity to achieved improved constructibility and efficiency of the power generation system.

Such a plant is also believed to represent an opportunity to mobilise a wider range of industrial resources than those typically engaged in the nuclear field, including in power electronics and metal stamping. This will enable the necessary industrial output to be harnessed to achieve a goal of rapid decarbonisation in line with international commitments under the Paris Agreement.

This work examines the implications of the introduction of direct contact heat exchangers to the steam plant of an exemplar CANDU 6 reactor in terms of constructibility and achievable power output. Whilst this reactor is unusual in terms of its low feedwater temperature and comparatively low steam pressure, it is believed that these results will be generalisable to the more common light water reactor fleet.

Prima facie, the modifications to the plant turbine system significantly increase plant output and reduce the number of tubular heat exchangers in the plant system to six, contained solely within the plant steam generators and moisture separator reheaters. This should allow a greater number of plants to be produced given limited fabrication resources although further design work is required to confirm this.

 

 

Presenting Author: Edmund Ireland University of Manchester

Authors:

Edmund Ireland University of Manchester