Plant Design and Cost Estimation of a Natural Circulation Lead-Bismuth Reactor with Helium Power Conversion Cycle

Abstract

The analysis of an indirect helium power conversion system with lead-bismuth natural circulation primary system has been performed. The work of this report is focused on 1) identifying the allowable design region for the important design parameters and 2) selecting the set of design parameter values for the helium secondary system which lead to the lowest electricity generating cost. An analysis was also performed to examine the capital cost of the ABR/GT and the sensitivity of the capital cost to key parameters. These capital cost estimation and sensitivity analyses were based on available cost estimates of the ALMR and a published HTGR/GT design.

The following optimal design parameter values for the helium secondary system were established by this report.

Pb-Bi in-tube design for the heat exchanger Triangular tube lattice in the heat exchanger Helium heat exchanger inlet temperature: 250 °C Helium heat exchanger outlet temperature: 500 °C Compression ratio: 3

The ABR/GT capital cost per unit electrical output with helium secondary system is about 36% above that of the steam secondary system case. Sensitivity analyses show about 10% reduction in cost is achieved by increasing the chimney height from 8 m to 15m, 22% cost reduction by increasing the capacity factor from 70-90% and 13% cost reduction by decreasing the construction time from 7 to 3 years. These cost reductions are comparable to those which can be achieved for the ABR with a steam secondary system. The increased cost for the helium versus the steam secondary side results principally from the thermal efficiency difference and the cost difference between steam cycle and helium cycle components.

This report is restricted to the capital cost of the ABR/GT. A previous report has estimated the ABR fuel cycle cost. Future economic analysis will include the O&M costs and updated capital estimates based on comparison with the S-PRISM primary system.