The SMR concepts included represent pressurized water reactors (5 inputs), pressurized light water cooled heavy water moderated reactors (1 input); high temperature gas cooled reactors (HTGRs, 1 input); liquid metal cooled fast reactors (1 input for sodium and 1 input for lead cooled reactors), and a single non-conventional design, which is a lead-bismuth cooled very high temperature reactor with pin-in-block HTGR type fuel.

Of the pressurized water reactors included, the KLT-40S (Annex I) has entered the deployment stage — construction began in 2007 in the Russian Federation of a pilot floating cogeneration plant of 400 MW(th)/ 70 MW(e) with two KLT-40S reactors. Actual deployment is scheduled for 2010.

Two reactors with integrated design of the primary circuit are in advanced design stages, and their commercialization could start around 2015. These are the 335 MW(e) IRIS design (Annex II) developed by the international consortium led by Westinghouse, USA; and the prototype 27 MW(e) CAREM (Annex III) developed in Argentina, for which construction is scheduled to be complete in 2011.

Two other PWR type designs, the SCOR (France) and the MARS (Italy) have the potential to be developed and deployed in the short term but show no substantial progress toward deployment. The SCOR, with 630 MW(e) (Annex IV), is in the conceptual design stage, and is of interest as it represents a larger capacity integral-design PWR. The modular MARS, with 150 MW(e) per module (Annex V), is at the basic design stage, and is of interest as it represents an alternative solution to other pressurized water SMRs, the solution based on the primary pressure boundary being enveloped by a protective shell with slowly moving low enthalpy water.

Advanced pressurized light water cooled heavy water moderated reactors are represented by one design — the AHWR, with 300 MW(e) (Annex VI). The AHWR (India) is at the detailed design stage with the start-up of construction related actions expected before 2010.

The GT-MHR, with 287.5 MW(e), a collaborative US-Russian concept of an HTGR with pin-in-block type fuel, is at the basic design stage (Annex VII). Its progress toward deployment may be not so advanced as that of some other HTGRs (e. g., the PBMR of South Africa or the HTR-PM of China [2]), however, as passive safety design features of all HTGRs have much in common, the GT-MHR is quite representative of the passive safety design options implemented in other HTGRs.

Sodium and lead cooled fast SMRs are represented by the 4S-LMR concept of a sodium cooled small reactor without on-site refuelling developed by the Central Research Institute of Electric Power Industry (CRIEPI) and Toshiba in Japan (Annex VIII) and by the SSTAR and STAR-LM concepts of small lead cooled reactors without on-site refuelling developed by the Argonne National Laboratory in the USA (both described in Annex IX). Of the two designs, the 4S-LMR with 50 MW(e) and a 10-year core lifetime is at a more advanced stage because the conceptual design and major parts of the system design have already been completed for a similar design differing essentially in the type of fuel and named the 4S. A pre-application review by the US NRC started in the fall of 2007. Construction of a demonstration reactor and safety tests are planned for early 2010 [3]. Different from this reactor type, both the SSTAR with 19.7 MW(e) and a 30-year core lifetime and the STAR-LM with 181 MW(e) and a 15-year core lifetime are at the pre-conceptual stage [3]. In 2008, due to

FIG. 2. Deployment potential map of innovative SMRs [2,3].

reduced funding, activities in the USA refocused on a lead cooled fast reactor (LFR) Technology Pilot Plant (a demonstration plant) under a GNEP programme.

Finally, non-conventional designs are represented by the CHTR with 100 kW(th) and a 15-year core lifetime (Annex X). The CHTR (India) is a small reactor without on-site refuelling designed to be a semi­autonomous ‘power pack’ for operation in remote areas and, specifically, for advanced non-electrical applications, such as hydrogen production. The CHTR is a non-conventional reactor merging the technologies of high temperature gas cooled reactors and lead-bismuth cooled reactors. The core uses 233U-Th based pin-in­block fuel of the HTGR type with BeO moderator blocks, while the coolant is lead-bismuth. When this report was prepared, an extensive research and development programme including both analytical studies and testing was in progress for the CHTR at the Bhabha Atomic Research Centre (BARC) in India [3].

Detailed design descriptions of the abovementioned and other SMRs, as well as some results of safety analyses performed for these reactors are provided in Refs [2, 3]. Figure 2 illustrates deployment potential of innovative SMRs. Brown indicates concepts with noticeable progress towards advanced design stages and deployment.