Early in 2011, there were about two dozen SMR design development projects ongoing worldwide. About twelve advanced SMRs currently being developed have reached advanced design stages and could in principle be implemented as FOAK or prototype plants before 2020. In some cases, pre-licensing negotiations or a formal licensing process have been initiated.

The majority of these near-term advanced SMRs are of PWR type, but there is one indirect cycle high temperature gas cooled reactor (using superheated steam in the power circuit), one advanced heavy water reactor (AHWR, being developed in India), two lead-bismuth cooled fast reactors, and one sodium cooled fast reactor.

PWRs constitute the majority of advanced SMR designs currently developed in the world. All of them could be divided in two design families:

• self-pressurised PWRs with in-vessel steam generators;

• compact modular PWRs (which are all Russian designs, sometimes referred to as “marine derivative” designs).

The gross electric output varies between 15 and 350 MW. The near-term advanced SMR projects fitting into the first group are CAREM-25 (Argentina), SMART (Republic of Korea), IRIS[78] (United States), Westinghouse SMR (United States), mPower (United States), and NuScale (United States). The Russian marine-derivative designs are KLT-40S, ABV, and VBER-300.

The self-pressurised PWR with in-vessel steam generators, also known as the integral design PWR, differ from conventional PWRs in that they have no external pressurisers and steam generators, with steam space under the reactor vessel dome acting as a pressuriser and steam generators being located inside the reactor vessel. Some of these designs also use the in-vessel (internal) control rod drives.

The compact modular SMR appears to be similar to conventional PWRs. However, the modules hosting the reactor core and internals, the steam generators, the pressuriser, and the coolant pumps are compactly arranged, and linked by short pipes (nozzles) with leak restriction devices. The pipes are mostly connected to the hot branch, and all primary coolant systems are located within the primary pressure boundary, so that the primary coolant system is sometimes referred to as “leak-tight”.

Barge-mounted advanced SMRs are all Russian designs. The KLT-40S and the ABV would be implemented first as barge-mounted twin-unit plants. The ABV is being considered for a land-based plant. The VBER-300 is land-based but could be configured to operate on a barge. All non-Russian SMRs are land-based plants.

There is only one near-term advanced SMR in the advanced heavy water reactor category. This is the Indian AHWR which is being design to operate on uranium-thorium or plutonium-thorium fuel. The AHWR is a pressure tube vertical type direct cycle plant with natural circulation of the coolant in all circuits and all operation modes. The primary coolant is boiling light water.

Among the near-term non water cooled advanced SMRs, the most advanced is the Chinese high — temperature gas cooled reactor HTR-PM which is an indirect cycle reactor employing the steam generators and a Rankine cycle with reheating for power conversion. The indirect cycle efficiency of the HTR-PM is remarkably high, 42%, due to steam reheating. The HTR-PM is intended to produce only electricity.

In addition to this, there are three non water cooled fast reactors in the advanced SMR category which target deployment in the near term. These designs include the sodium-cooled 4S (Japan) and the lead-bismuth cooled SVBR-100 (the Russian federation) and New Hyperion Power Module (United States). All of these designs operate at a nearly atmospheric primary pressure and employ in­vessel steam generators or primary heat exchangers. The 4S has an intermediate heat transport system. Regarding advanced SMRs — fast reactors it is noted that all of them incorporate a high degree of innovation related to long refuelling interval and, therefore, only the prototype plants could be expected by 2020.

Pressurised water reactors (PWRs, see a brief description in Box 4.1) constitute the majority of nuclear power reactors currently in operation, accounting for 61% of the total reactor fleet in the world [4.3]. PWRs also constitute the majority among the power reactors being currently constructed. In 2010, out of 60 new nuclear power units under construction, 54 were with PWRs [4.4].

Basic characteristics of advanced SMR designs addressed in the present section1 are summarised in Table 4.1. In contrast to the PWR SMR currently available for deployment (and discussed above), some of the advanced SMRs do not always follow the conventional PWR layout. Generally speaking, the PWR designs shown in Table 4.1 could be divided in two major categories: Self-pressurised PWRs with in-vessel steam generators and compact modular PWRs[13] [14].

Westinghouse SMR 800/225 In batches/24 months

• Self-pressurised PWRs with in-vessel steam generators. The self-pressurised PWR with in-vessel steam generators, also known as the integral design PWR, are represented by the CAREM-25 and CAREM-300, SMART, IRIS, IMR[16], mPower, NuScale, and NHR-200 (see example at Figure 4.1). These designs differ from conventional PWRs in that they have no external pressurisers and steam generators, with steam space under the reactor vessel dome acting as a pressuriser and steam generators being located inside the reactor vessel. Some of these designs, namely, the CAREM, the IRIS, the IMR, the mPower, and the NuScale also

use the in-vessel (internal) control rod drives. CAREM-25, IMR, NuScale, and NHR-200 use natural circulation of the primary coolant in normal operation mode and have no main circulation pumps. Other designs use in-vessel canned pumps.

• Compact modular PWRs. The compact modular SMRs, referred to as the “marine derivative” Russian designs in [4.2], appear to be similar to a conventional PWRs. However, the modules hosting the reactor core and internals, the steam generators, the pressuriser, and the coolant pumps are compactly arranged, and linked by short pipes with leak restriction devices. The pipes are mostly connected to the hot branch, and all primary coolant systems are located within the primary pressure boundary, so that the primary coolant system is sometimes referred to as “leak-tight”. The designs belonging to this group are VBER-300, KLT-40S (described in Section 3), and ABV. The ABV holds an intermediate position between the two groups as it has internal steam generators and uses natural convection of the primary coolant but employs an external gas pressuriser.

The general characteristics of advanced PWR SMRs could be summarised as follows:

• All of the PWR-based SMRs in Table 4.1 are land-based, with the exception of the ABV. This reactor was developed as barge-mounted but could also be based on land. The VBER-300 is land-based but could also be configured to operate on a barge.

• The electric output varies between 15 and 350 MWe. The NHR-200 is a dedicated reactor for heat production. The targeted availability factors are typically around 90% or even higher.

• The plant operational lifetime is in line with that of a modern conventional PWR: generally 60 years, with 50 years for the ABV and 40 years for the NHR-200. [17]

• The refuelling intervals are longer, the bum-up levels are higher and the plant lifetime is longer, compared to the currently available SMRs. Some of the advanced PWR SMRs offer greater flexibility in capacity deployment (e. g. multi-module plant configurations).

• Of the designs presented, the ABV is a factory fabricated and fuelled reactor designed for 12 years of continuous operation, and the core of the mPower is refuelled after 4.5-5 years of continuous reactor operation. Other designs rely on partial core refuelling in batches. The refuelling intervals are mostly between two and four years. IRIS is being designed for a 4-year refuelling interval (with an 8-year refuelling interval being considered as an option), while CAREM provides for annual refuelling.

• The SMART, the ABV, and the NHR-200 target distributed deployment, while for all other designs both concentrated and distributed deployment are targeted. Twin-unit option is provided for the IRIS, IMR, and VBER-300. The ABV is a twin-unit barge-mounted reactor. The mPower and the NuScale are being designed for multi-module plants of flexible capacity.

• The primary pressure is set to 15-16 MPa in most cases (as in a conventional large PWR). However it is ~12 MPa for the CAREM, ~13 MPa for the mPower, ~11 MPa for the NuScale, and only 2.5 MPa for the NHR-200.

• The fuel is typically UO2 with less than 5% enrichment in 235U (as in large light water reactors). The exception is the ABV which, similar to the KLT-40S, uses cermet fuel with uranium enriched in 235U to slightly less than 20%.

• The average projected fuel burn-up is between 30 and 70 MWday/kg, but typically around 40 MWday/kg or slightly above.

• Several of the designs offer compact containments with maximum dimensions less than 15-25 m. These are the IRIS, the IMR, the ABV, the NuScale, and the NHR-200. For the ABV, all primary containment dimensions are within 7.5 m.

• The plant surface areas, where indicated, vary and depend on plant configuration[18]. The minimum areas are indicated for the ABV (6 000 m2 on the coast and 10 000 m2 in the bay) and NHR-200 (8 900 m2). In other cases the areas are between ~100 000 and 300 000 m2, with a substantial reduction in the relative size of the area needed for twin or multi-module units.

In the United States, fossil primary sources (mainly coal and gas) were used to generate more than 70% of electricity in 2008. About 19% of electricity was generated by nuclear power plants and about 6.5% by hydropower plants (see Figure 7.8).

Figure 7.8. Sources of electricity generation in the United States [7.4]

Gross electricity production (in TWh) by source in 2008

Other, 148.34

I

■——- Nuclear,

— “

In the US market, the nuclear option is competitive with other technologies for generating electricity (Table 7.13). Large reactors are more competitive than smaller ones. Although the NPPs with large reactors have smaller LUEC than SMRs, the latter could represent an attractive option in the case of a liberalised market (since they could be easier to finance, see the discussions in Sections 6.5 and 6.6) or for specific site conditions. Also, in the United States, there are other motivations than economics to develop SMRs (increasing exports of US companies, creation of jobs, replacement of small and medium size fossil plants, powering military bases, etc.) that are out of scope of the present report. More information could be found in [7.13].

The specific, per kWe of installed capacity, overnight capital cost is known to be reduced as the plant size is increased. This is due to economies of raw materials and optimisation that could be realised while building larger reactors.

Reference [6.4] suggests the following scaling function that can be used to illustrate the effect of changing from a unit size P0 to Pi (see Figure 6.3) for the same design but different capacity:

/Р n

Cost(P1) = Cost(P0) ^) (6.3)

where

Cost (P1) = Cost of power plant for unit size P1,

Cost (P0) = Cost of power plant for unit size P0, and

n = Scaling factor, obtained for reactors with unit power from 300 to 1 300 MWe, is in the range of 0.4 to 0.7 for the entire plant

Specific cost (in USD per kWe)

Cost (Po) ^ Cost (P,) Cost (Po) /P,

Po P, = Po VPo/

Example

Consider a single-reactor NPP of P0=1 000 MWe having a cost equal to Cost (1 000 MWe). Then a larger single-reactor power plant of similar design, say, of 1 500 MWe, would cost (for n = 0.5):

Cost (1 500 MWe)= Cost (1 000 MWe)x(1.5)05 =1.2x Cost (1 000 MWe).

Thus, the total cost of a larger plant is higher than the cost of a smaller plant. At the same time the specific cost (per kWe) of the larger NPP would be19% less than that of a smaller 1 000 MWe plant. [45] [46]

i. e., for two smaller capacity plants it is smaller than for two larger capacity plants. The total scaling factor from Table 6.6 is 0.51.

• A third study performed for the AP1000 and AP600 plants gives n = 0.6 for scaling of the direct costs, see reference [6.7].

Based on the above mentioned data, for the purposes of the present report it was assumed that the most probable values for the factor n are in the interval 0.45-0.6[47], with an average of n=0.51.

Table 6.7 illustrates the range of possible impacts of the scaling law (6.3) on the specific (per kWe) capital costs of SMRs compared to a nuclear power plant with large reactors. The data in Table 6.7 indicate the scaling law to be an important factor negatively affecting the specific capital cost and, consequently, the LUEC of SMRs. For example, if it were applied directly, replacing a large 1 200 MWe reactor with four small reactors of 300 MWe, it would require an investment 75-155% higher.

At the same time, there are other economic factors that could be favourable to smaller reactors and compensate, to a certain extent, the negative impact of the economy of scale. These factors and their impact are analysed in the following sub-sections.

This section identifies, on a generic level, some of the regulatory issues that might be faced by advanced SMRs in some countries. To make the consideration fair, no reference is made to any specific design or country.

9.1.1 General issues

With the increased number of planned and ongoing NPP construction projects worldwide, a delay in licensing of any non-conventional, advanced SMRs may result from the regulatory staff being busy dealing with the applications for NPPs with conventional large-sized water cooled reactors. A governmental programme to support licensing of selected advanced SMRs could help overcome the corresponding delays.

The resulting LUEC estimates were compared to the designers’ cost data (see Figure E.4). Such a comparison was found useful in understanding the various factors influencing the economics of SMRs, and also to highlight the points that may need further clarification. The major findings of the comparison are the following:

• The LUEC estimates are quite sensitive to the selection of the parameter for the scaling law, and the inclusion of the heat credit. It is not clear if the designers have included the heat credit in their announced LUEC values. Thus, two cases have been considered:

— If the heat credit is not taken into account the majority of the independent LUEC estimates are significantly higher when compared to the designers’ data on LUEC.

— If heat credit is taken into account (where it applies), most of the independent LUEC estimates for land-based SMRs envelope the designers’ data on the LUEC.

— However, the independent LUEC estimates for some barge-mounted SMRs are significantly higher than the designers’ data. No explanation has been found for this.

Figure E.4. Difference (in %) between estimated LUEC and the designers’ values for LUEC (dark blue).

light blue — heat credit

200

Figure E.5 plots the overnight cost for SMR based plant configurations of Table E.2 versus the total net electric outputs of the plants. It can be seen that, even though the specific investment costs (per kWe) for SMRs are in some cases rather high, the total investments are relatively small for a small reactor. For single module SMR plants with the electric output below 125 MWe the total investments are below USD 1 billion.

Another interesting feature of SMRs is that they could be incrementally deployed in relatively short time frames, owing to a shorter construction period. Together with low per-unit costs, this could lead to a significant reduction of the front-end investment and the capital-at-risk, when compared to using large reactors to increase capacity.

In view of the above mentioned issues, there is an increasing interest of private investors in SMRs. Recently the so-called “mini” or small and modular reactors have attracted a lot of attention. Since 2008, several small private companies have been created in the United States to support the design development, patenting, licensing and commercialisation of several new SMR concepts.

The attributes of small and modular reactors, such as small upfront capital investments, short on-site construction time (with the accordingly reduced cost of financing), and flexibility in plant configuration and applications are attractive for private investors.

In the United States, the formation of public-private partnership supporting the certification and licensing of small and modular reactors is being supported by the new Small and Modular Reactor programme of the Office of Advanced Reactor Concepts belonging to the Office of Nuclear Energy of the Department of Energy (DOE) which started in May 2011. In the Russian Federation, a public — private joint venture company named “AKME Engineering” was recently created to drive forward the project of the SVBR-100 reactor expected to be constructed by 2017 (see Table E.1).

Figure E.5. Overnight cost for various SMRs and large reactor deployment projects

In Chapter 6 the non-site-specific factors affecting the competitiveness of SMRs have been reviewed. The review focused on a relative impact of each of the considered factors on the economy of a NPP with SMRs versus that of a NPP with a large reactor.

One of the main factors negatively acting on the competitiveness of SMRs is the economy of scale. Depending on the power level, the specific (per kWe) capital cost of SMRs are expected to be tens to hundreds percents higher than for large reactors.

Other factors tend to ameliorate the capital costs of SMRs. These are:

• The reduction of the construction period resulting in a significant economy in the costs of financing. This is particularly important if the interest rate is high.

• The savings from building subsequent units on the same site and from serial production of factory-built SMRs (“learning in construction” and “sharing of common facilities on the site”).

• The design simplification due to inherent properties of particular SMRs.

In some cases, additional design specific factors allow further reduction of capital costs, e. g., for the barge-mounted plants.

However, even taking all above factors into account, one can conclude that the specific capital costs of SMRs would probably be higher than those of a large plant. As an example, four integral type or marine derivative PWRs of 300 MWe (and not FOAK) built on the same site may have the effective per unit specific overnight capital costs of about 10-40% higher compared to those of a NPP with a single large PWR of 1 200 MWe. As another example, a five-module NPP with such 300 MWe reactors may have overnight capitals costs that are about 7-38% higher compared to those of a NPP with a single large PWR of 1 500 MWe.

A very important benefit of SMRs is that they could be incrementally deployed in shorter time frames. This allows a significant reduction in front-end investment and capital-at-risk compared to capacity increase with large reactors.

The levelised unit cost of electricity generated by SMRs and large reactors is design — and site — specific. However, several conclusions on the factors influencing the LUEC could be made:

• The LUEC share of O&M and fuel costs for SMRs (17-41%) is noticeably below that of large reactors (45-58%).

• Co-production of heat or desalinated water leads to a significant credit expressed in USD per MWh. This credit could be subtracted from the total unit cost to establish an equivalent of the levelised cost of producing only electricity. In this case the values of LUEC could be improved by about 20-30% (for some SMR designs).

In the following chapter, several design — and site-specific estimates of the capital cost and LUEC will be performed, in order to illustrate the competitiveness of SMRs compared to the alternative energy sources in some electricity and heat markets around the world.

References

[6.1] IEA/NEA (2010), Projected Costs of Generating Electricity: 2010 Edition, OECD, Paris,

France.

[6.2] IAEA (2007), Status of Small Reactor Designs without On-site Refuelling, IAEA-TECDOC-

1536, Vienna, Austria.

[6.3] IAEA (2010), “Small Reactors without On-site Refuelling: General Vision, Neutronic

Characteristics, Emergency Planning Considerations and Deployment Scenarios” — Final Report of IAEA Coordinated Research Project on Small Reactors without On-site Refuelling, IAEA — TECDOC-1652, Vienna, Austria.

[6.4] IEA/NEA (2000), Reduction of Capital Costs of Nuclear Power Plants, OECD, Paris, France.

[6.5] IAEA (2010), “Approaches to Assess Competitiveness of Small and Medium Sized Reactors”,

Proceedings of the International Conference on Opportunities and Challenges for Water Cooled Reactors in the 21st Century, 27-30 October 2009, Paper 1S01.

[6.6] Rouillard, J. and J. L. Rouyer (1992), “Commissariat a l’energie atomique”, contributor to IAEA-

TECDOC 666, Technical and Economic Evaluation of Potable Water Production Through Desalination of Sea Water by Using Nuclear Energy and Other Means.

[6.7] Paulson, C. K. (2006), “Westinghouse AP1000 advanced plant simplification results, measures,

and benefits”, ICONE-10, (Proc. 10th Int. Conf. on Nuclear Engineering). Arlington VA.

[6.8] IAEA (2006), Status of Innovative Small and Medium Sized Reactor Designs 2005: Reactors

with Conventional Refuelling Schemes, IAEA-TECDOC-1485, Vienna, Austria.

[6.9] Mitenkov, F. M., B. A. Averbakh, I. N. Antiufeeva, L. V. Gureeva (2004), “Conceptual analysis of

commercial production experience and influence of main factors on the economy of propulsion nuclear plant lifecycle”. Proceedings of the 2-nd International Scientific and Technical Conference “Energy-Strat’2004: Power development planning: methodology, software, applications”, Moscow, the Russian Federation.

[6.10] IAEA (2000), Safety of the Nuclear Power Plants: Design Requirements, Safety Standards Series, No. NS-R-1, IAEA, Vienna, Austria.

[6.11] OKBM update on the VBER-300 design description in IAEA-TECDOC-1485, OKBM Afrikantov, the Russian Federation, 2009.

[6.12] Krysov, S. V., A. A. Andreev, V. A. Sozoniuk (“Rosenergoatom”), V. V. Petrunin, L. V. Gureeva and S. A. Fateev (2007), Potential for Improving Economic Efficiency of Floating and Land — based NPPs of Small and Medium Power/IAEA Technical Meeting "Approaches to Improve Economic Efficiency of Small and Medium Power Reactors”, IAEA, Vienna, Austria.

[6.13] KLT-40S Main Data Tables & Diagram (2010), Nuclear Engineering International: www. neimagazine. com/joumals/Power/NEI/January_2010/attachments/KLT- 40S%20Data%20&%20Diagram. pdf

[6.14] NEA (2009), The Financing of Nuclear Power Plants, OECD, Paris, France.

[6.15] Boarin, S. and M. Ricotti (2009), “Cost and Profitability Analysis of Modular SMRs in Different Deployment Scenarios”, Proceedings of the 17th International Conference on Nuclear Engineering (ICONE 17), Brussels, Belgium, Paper ICONE17-75741.

[6.16] Written Testimony of Christofer M. Mowry President, Babcock & Wilcox Nuclear Energy, Inc. The Babcock & Wilcox Company Before the Committee on Science and Technology U. S. House of Representatives, May 19, 2010. Available at:

https://smr. inl. gov/Document. ashx? path=DOCS%2FCongressional+Testimony%2FMowry_test

imony_B%26W. pdf

[6.17] OKBM update on the KLT-40S design descriptions in IAEA-TECDOC-1391 and IAEA Nuclear Energy Series Report NP-T-2.2, OKBM Afrikantov, the Russian Federation, 2009.

[6.18] IAEA (2008), Energy, Electricity and Nuclear Power for the period up to 2030, Reference Data Series No. 1, IAEA, Vienna, Austria.

[6.19] IAEA (2007), Status of Nuclear Desalination in IAEA Member States, Small Reactor Designs without On-site Refuelling, IAEA-TECDOC-1524, Vienna, Austria.

[6.20] Il Soon Hwang, et al, (2008) “PASCAR-DEMO — a Small Modular Reactor for PEACER Demonstration”, KNS spring.

[6.21] Il Soon Hwang 2009, (NUTRECK, SNU, Republic of Korea). Private communication.

NPP operation in a co-generation mode (for example, with co-production of heat or desalinated water) is not a prerogative of SMRs. On a technical level it could be realised in NPPs with large reactors as well. It has not been done so far for NPPs with large reactors because their primary designation was to produce electricity.

Examples exist when NPPs with SMRs have been used or are being used for co-production of the non-electrical energy products. The main reasons why non-electrical applications are more often considered for SMRs are as follows:

• Some small reactors target the niche markets in “off-grid” remote or isolated areas where non-electrical energy products are as much a value as the electricity is.

• Many SMRs are considered as possible replacement for the currently operated combined heat and power plants (CHPs). In many countries the distribution networks serviced by CHPs are tailored to the equivalent plant capacity of 250-700 MWe. Therefore, the use of a NPP with SMRs as a replacement would allow making full use of these networks (that cannot accommodate a large plant).

In regards to hydrogen or other advanced energy carriers requiring high temperature heat to be produced, HTGRs are being considered for this purpose. They all fit into the SMR category.

A somewhat cautious attitude of SMR designers to the inclusion of non-electrical applications in the designs of their FOAK plants is noted, which reflects the fact that some recent market surveys have shown the electricity applications to be of prime demand worldwide for the nearest decade. With this in mind, some of the designers intend to carry on with fastest deployment of the ‘electricity-only’ versions of their SMRs, reserving the non-electrical applications for a more distant future.

Notwithstanding what is said above, district heating is included as a FOAK design feature in all of the Russian PWR SMR designs, with the production of desalinated water specified as an option. Water desalination is included as a FOAK design feature in the Indian AHWR and the Korean SMART concepts.

Boiling water reactors (BWRs) are second to PWRs in global deployment, accounting for nearly 21% of all currently operated reactors. However, in 2010, out of 60 new nuclear power units under construction, only 2 were BWRs [4.4].

BWRs are single circuit, direct cycle plants. The coolant is boiling light water. Saturated steam condensation cycle (Rankine cycle) is used for energy conversion.

A conventional state-of-the-art BWR (e. g. the ABWR [4.5]) is self-pressurised and includes the reactor pressure vessel hosting the reactor core and the steam separators and dryers, the bottom

mounted external control rod drives, and the bottom mounted external canned recirculation pumps. There are no BWRs in the small and medium-size range currently available for deployment.

The two advanced BWR SMR designs presented in this report[19] are different from ABWRs in that they use top-mounted external control rod drives (such as in PWRs) and rely on natural circulation of the coolant in all operating modes (i. e., they have no recirculation pumps), see Table 4.2. Proposals to use natural circulation of the coolant are not unique to small or medium-sized BWRs. For example, no recirculation pumps are used in the design of the ESBWR of 1 550-1 600 MWe [4.5].

The designs discussed here are quite different from conventional BWRs[20], and have the following

features:

• The CCR of 400 MWe uses compact high pressure containment with its maximum dimension (height) limited by 24 meters, and with the reactor building structures providing the secondary containment.

By using compact high pressure containment, the CCR aims to reduce the volume and mass of the reactor building and nuclear island components proportionally to the power reduction from a conventional large sized ABWR, an approach to overcome the disadvantage of the economy of scale [4.1].

• The VK-300 of 250 MWe is placed within a conventional large PWR type containment (about 45×60 m) within which a primary protective hull (the primary containment) and a gravity driven water pool are located.

• Both designs are land-based reactors; however, location of the VK-300 on a barge is not excluded.

• The projected plant lifetime is 60 years and the targeted availability factors are above 90% for both designs.

• For the VK-300 the construction duration is five years, while for the CCR it is claimed to be only two years, a minimum among all advanced SMR designs addressed in this study. It is expected that such a short construction period is based on the experience of building the

ABWR[21] and taking benefit of the design compactness to maximise factory fabrication of large reactor modules [4.1].

• Both designs use low enrichment UO2 fuel with partial core refuelling in batches. Twin-unit and multi-module plant options are being considered for the CCR.

• For both designs the main specifications are similar to those of the state-of-the-art BWRs. Notably, a very small plant surface area of 5 000 m2 is indicated for a single module CCR.

In this section, the competitiveness of the SMRs is analysed for countries with interconnected electricity grids (i. e. for “on-grid” locations). Niche markets for SMRs in the remote and isolated (“off-grid”) locations are analysed in Section 7.2.5.

The evaluation presented in the previous section was limited to SMRs and alternative technologies intended for generating electricity. Some of the power plants currently operating worldwide, as well as many advanced SMRs, provide for the simultaneous production of electricity and heat in a co-generation mode. Such plants are referred to as Combined Heat and Power Plants (CHPs) [7.1]. As the produced heat is transformed into a commercial product (heat for district heating, desalinated water, etc.) and sold along with the generated electricity, co-generation mode may contribute to the enhancement of the overall plant economy. The heat credit model proposed in reference [7.1] and discussed in Section 6.5 is used to take into account the associated benefits.

To evaluate the deployment potential of co-generating nuclear power plants with SMRs, the LUEC estimates for SMRs from Table 7.7 in Section 7.2.1 were compared to the LUEC values for the CHP from Table 3.7e of [7.1]. The latter publication takes into account the heat credit at a fixed rate of USD 45/MWh.

The evaluation results are summarised in Table 7.14, which generally has the same structure as Table 7.8-Table 7.13 of the previous section. Regarding these results one should note that:

• Countries rather than technologies are listed in the left column of the table, i. e., the specified ranges of LUEC for CHPs encompass all technologies specified in [7.1] for a particular country.

• All SMRs evaluated in this chapter (PWR SMRs) were considered as capable of producing heat in the co-generation scheme (and not only those for which heat credit data are specified in Table 7.6).

The main argument for the last point is that almost all SMR designers do not exclude the non­electrical applications and co-generation modes for their designs as discussed in Section 4.4. For the SMRs from Table 7.6 — PWR-8TB, PWR-35TB, PWR-90SL, and PWR-302TL — the LUEC estimates taking into account heat credit were taken from the Table 7.7, while for all other SMRs from the same table, the LUEC values used in the evaluation had no correction for the heat credit.

The data from Table 7.14 leads to the following conclusions:

• At least some SMRs could be competitive with other CHP technologies in China and in the Russian Federation at 5% discount rate[63]. As co-generation modes are typically not provided for in NPPs with state-of-the-art large reactors, NPPs with SMRs appear to be the only nuclear option for a CHP.

• It is noted that in the case of the Russian Federation, the SMR based CHPs are competitive with gas turbine and Combined Cycle Gas Turbine (CCGT) CHP that fill-in the upper part of the LUEC ranges specified in Table 7.14. Plants with SMRs cannot compete with the Russian coal-fired CHP for which the LUEC values (without carbon pricing) are at the lower boundary of the LUEC ranges of Table 7.14. In contrast, in the Chinese case, the specified co-generation NPPs with SMRs are competitive with the coal-fired CHPs.

• In the case of the United States, reference [7.1] includes the CHP LUEC data only for the two technologies, biomass and simple gas turbine. Both appear so cheap that no SMRs could compete with any of them at either a 5% or 10% discount rate.

• Similar to what was found in Section 7.2.2, the evaluation performed in this section has found no cases when small barge-mounted co-generation plants with the PWR-8 and PWR — 35 twin-units (based on the Russian ABV and KLT-40S designs) are competitive (in the considered “on-grid” CHP applications).