A Small-Sized HTGR System Design for Multiple Heat Applications for Developing Countries

Table 4

Design specification of HTR50S core for the 1st step of phase I.

Layer	^235U enrichment (wt%)				Burnable poison (BP) specifications; Upper: diameter (mm); Lower: natural boron concentration (wt%)
	Fuel region^*1
	1	2	3	4	1	2	3	4
1st	6.5	6.5	8.7	8.7	NA^*2	NA^*2	NA^*2	NA^*2
2nd	6.5	6.5	8.7	8.7	18.0; 2.5	18.0; 2.5	18.0; 2.5	18.0; 2.5
3rd	4.6	4.6	6.5	6.5	13.0; 2.5	13.0; 2.5	18.0; 2.5	18.0; 2.5
4th	4.6	4.6	6.5	6.5	13.0; 2.5	13.0; 2.5	18.0; 2.5	18.0; 2.5
5th	4.6	4.6	4.6	4.6	13.0; 2.5	13.0; 2.5	13.0; 2.5	13.0; 2.5
6th	4.6	4.6	4.6	4.6	13.0; 2.5	13.0; 2.5	13.0; 2.5	13.0; 2.5

∗1Shown in Figure 2.
∗2Not installed.