*Appendix A.3 Unit D*

For Unit D, two retrofit proposals were designed.

#### Appendix A.3.1 Retrofit Proposal 5

In this retrofit proposal, the area in HX-D1 is increased to increase the heat recovery from the hot reactor effluent. When the pre-heating before furnace HTR-D1 is increased, the furnace will not be needed during normal operation. As the hot inlet temperature to SG-D is decreased, the steam generation is also decreased. In addition, the steam generation is further decreased as a consequence of that the pre-heating and superheating that occurs in furnace HTR-D1 is removed if the furnace is shut down during normal operation. The proposal is shown in Figure A10.

**Figure A10.** The process current configuration is shown to the left in the figure and retrofit proposal 5 is shown to the right.

#### Appendix A.3.2 Retrofit Proposal 6

In retrofit proposal 6, fuel is saved in furnace HTR-D2 by pre-heating the feed by another hot process stream. As in retrofit proposal 5, retrofit proposal 6 leads to lower steam production in steam generator SG-D. The proposal is shown in Figure A11.

**Figure A11.** Left part of the figure shows current process configuration and right part of the figure shows the suggested retrofit proposal 6.
