Assessment of impact of fuel cycle back end options on levelized unit electricity cost of produced electricity based on nuclear fuel cycle in Armenia

3.1.2.1. Introduction

The general objective of the fuel cycle back end Armenian case study under Task 2 of the IAEA SYNERGIES project is to develop different options for management of spent nuclear fuel. An important factor for selecting a strategy for final spent nuclear fuel management is an economic evaluation that allows a comparative analysis of different scenarios of the nuclear fuel cycle and/or reveals the influence of the different components of the nuclear fuel cycle on the entire fuel cycle cost. Finding a solution for spent nuclear fuel may determine the direction of implementation of the national strategy for the further development of nuclear power generation. Due to the amount of accumulated spent fuel and the lack of generally accepted solutions for its optimal final management, a long term assessment is necessary to determine the impact on the cost of electricity produced by nuclear power plants in the various spent fuel scenarios.

Common approaches for assessing the impact of the final stage of the nuclear fuel cycle on the levelized unit energy cost (LUEC) when considering an ‘idealized model’ are presented in Ref. [3.4]. It is shown that the assessment of the final stage impact of the nuclear fuel cycle requires determining the value of the entire fuel cycle, including the construction costs of nuclear power plants, nuclear fuel procurement, maintenance, storage and disposal of spent nuclear fuel.

This study is performed under the SYNERGIES Task 1, Scenario C.3: Russian Federation, Ukraine and Armenia case study on the water cooled, water moderated power reactor (WWER)–fast reactor collaborative deployment scenarios aimed at solving the problem of accumulating spent fuel inventory to match fast reactor deployment needs. For the reference scenario, an option for long term storage of spent fuel at the nuclear power plant site with no restrictions on spent nuclear fuel accumulation has been considered. For sensitivity analysis, the study considers the options for removal of spent fuel from the nuclear power plant site and export to another country for reprocessing using different transport solutions (road, rail and air). The complete case study can be found in Annex I on the CD-ROM accompanying this publication.

3.1.2.2. Objective and problem formulation

The objectives are the following:

(i) Collection and analysis of baseline information on the current status and projections of the development of nuclear power in Armenia.

(ii) Development of a model for nuclear fuel cycle options, including:

— Spent fuel storage at the nuclear power plant site;

— Spent fuel storage at the nuclear power plant site and removal of spent fuel from nuclear power plant site to geological disposal;

— Export of spent fuel from Armenia using different transport solutions (road, rail and air) for reprocessing and final disposal in another country.

(iii) Assessment of the impact of spent fuel management costs on the cost of electricity produced by nuclear power plants.

(iv) Development of recommendations on optimizing the cost of spent fuel management and sustainable nuclear energy development in Armenia.

3.1.2.3. Assumptions, methods and data used

(a) General assumptions

The Armenian energy system is modelled by generation forms, independent of specific power units and regional features. To cover the growing electricity demand and to provide the contractual obligations with the Islamic Republic of Iran, only the implementation of nuclear technologies can be proposed. It is assumed that the WWER-1000 unit will replace the existing Armenian nuclear power plant in 2026. Starting from 2035, six VBER-300³ reactors will come into operation for each decade. The last (sixth) VBER-300 will be introduced into the power system in 2095. It is assumed that seven LWRs with uranium oxide (UOX) fuel will be commissioned by 2100.

Armenia has no nuclear fuel cycle industry and uses an open nuclear fuel cycle. The existing WWER-440 nuclear unit operates with a three year fuel cycle. The spent nuclear fuel, before its transfer to the dry storage, is kept for 5 years in the reactor cooling pool.

In 2000, the construction of the first stage of the spent fuel dry storage facility was completed. The construction was performed with Framatome (France). The spent fuel dry storage facility has been put into operation, and the transfer of spent fuel is performed according to the requirements of the license given by the Armenian Nuclear Regulatory Authority. The volume of the first stage of storage is now completely filled with spent fuel.

In 2005, an agreement was signed with AREVA TN International (France) for construction of the additional three stages of the dry storage facility. The financing was allocated from the State budget. The second stage was completed and put into operation in the spring of 2008 and the first part of the spent nuclear fuel has been transferred into dry storage. The third stage of spent fuel dry storage construction is planned to be started in 2015.

In order to perform the mentioned assessment, the discount rate is taken at 10% for all the considered scenarios. The following input data for all scenarios were used.

(b) Data used for the front end of the nuclear fuel cycle

— Uranium resources: Uranium resources are considered to be unlimited during the modelling period. The cost of natural uranium is considered at US $110/kg.

— Conversion and enrichment: Historically, the cost of conversion services varied between US $8–15/kg HM [3.5]. This value is assumed to be US $7.5/kg HM in the model. Uranium conversion stage is considered as a service. The process of uranium enrichment is considered as a service with a cost

3 VBER-300 is a medium sized PWR being developed by Afrikantov Experimental Design Bureau for Mechanical Engineering (OKBM) (Russian Federation).

TABLE 3.3. TECHNICAL AND ECONOMIC PARAMETERS OF THE REACTORS USED IN THE MODEL

Parameter WWER-440 WWER-1000 VBER-300

Heat capacity (MW) 1375 3000 912

Electric capacity (MW) 375 1060 325

Efficiency (%) 32 35

Installed capacity utilization factor (%) 72 85 85

Fuel enrichment (%) 3.8 4.3/4.7 5

Av. burnup for fuel assemblies (MW·d/kg) 42.66 48/60 60

First load (t HM) 40.2^a 68.4/72.8^b 22.2

Annual reload (t HM) 9.00^a 20.2/16.1^c 4.4

Overnight cost (US $/kW) — 5000 5500

Fixed costs (US $/kW) 50 50 50

Variable costs (US $/MW·h) 1 1 1

Operation lifetime (years) 13^d 60 60

Construction period (years) — 6 5

Fuel fabrication (US $/kg) 300 300 300

Construction of spent fuel dry storage (US $/kg) 150 150 150

Cost of disposal of spent nuclear fuel (US $/kg) 600 600 600

a The first load: 115.2 kg × 349 pcs = 40 204.8 kg; annual reload: 115.2 kg × 78 pcs = 8985.6 kg.

b The first load: (old fuel) 163 pcs × 494 kg × 0.85 = 68 443.7 kg; (new fuel) 163 pcs × 545 kg × 0.85 = 72 844.0 kg.

c Annual reload: (old fuel) 36 pcs × 545 kg × 0.85 = 16 088 kg; (new fuel) 48 pcs × 494 kg ×0.85 = 20 155 kg.

d From the starting year (2013) to the decommissioning year (2026) of the modelling.

per separative work unit (SWU) of US $160 purchased on the world market [3.5]. It is assumed that the global market for uranium enrichment services is not limited. Tails assay is 0.25%.

— Fuel fabrication: Fabrication of fresh fuel for LWRs is considered as service purchased at the price of US $300/kg HM. Average world prices of fuel fabrication for PWRs were US $250/kg HM in 2008 [3.6].

— WWER-440 unit: Real economic data were used for tariffs.

(c) Data used for light water reactors

Three types of LWR are considered in the scenarios: WWER-440, WWER-1000 (Project B-392) and VBER-300. It is planned to commission only one WWER-1000 reactor in 2026. After that, a series of small reactors (VBER-300) are expected to be implemented up to the end of the century. The technical and economic data of considered reactors are presented in Table 3.3 [3.7].

Four different fresh nuclear fuels modification have been modelled in this study. Their parameters are presented in Table 3.4 [3.7].

(d) Data used for the back end of the nuclear fuel cycle

The technical and economic data are presented in Table 3.5.

TABLE 3.3. TECHNICAL AND ECONOMIC PARAMETERS OF THE REACTORS USED IN THE MODEL

Parameter WWER-440 WWER-1000 VBER-300

Heat capacity (MW) 1375 3000 912

Electric capacity (MW) 375 1060 325

Efficiency (%) 32 35

Installed capacity utilization factor (%) 72 85 85

Fuel enrichment (%) 3.8 4.3/4.7 5

Av. burnup for fuel assemblies (MW·d/kg) 42.66 48/60 60

First load (t HM) 40.2^a 68.4/72.8^b 22.2

Annual reload (t HM) 9.00^a 20.2/16.1^c 4.4

Overnight cost (US $/kW) — 5000 5500

Fixed costs (US $/kW) 50 50 50

Variable costs (US $/MW·h) 1 1 1

Operation lifetime (years) 13^d 60 60

Construction period (years) — 6 5

Fuel fabrication (US $/kg) 300 300 300

Construction of spent fuel dry storage (US $/kg) 150 150 150

Cost of disposal of spent nuclear fuel (US $/kg) 600 600 600

a The first load: 115.2 kg × 349 pcs = 40 204.8 kg; annual reload: 115.2 kg × 78 pcs = 8985.6 kg.

b The first load: (old fuel) 163 pcs × 494 kg × 0.85 = 68 443.7 kg; (new fuel) 163 pcs × 545 kg × 0.85 = 72 844.0 kg.

c Annual reload: (old fuel) 36 pcs × 545 kg × 0.85 = 16 088 kg; (new fuel) 48 pcs × 494 kg ×0.85 = 20 155 kg.

d From the starting year (2013) to the decommissioning year (2026) of the modelling.

3.1.2.4. Summary presentation and analysis of the results

(a) Summary presentation

Three scenarios of spent nuclear fuel management options considered in the study are presented in Table 3.6.

The results of economic analyses of nuclear fuel scenarios according to Table 3.6 are summarized below.

(b) Analysis of the results: Management of spent fuel without construction of small reactors (i) Construction of the spent fuel dry storage at the nuclear power plant site

This scenario assumes that the existing WWER-440 reactor will produce electricity until 2026. After decommissioning of the existing unit, a new WWER-1000 type reactor will be introduced into the national grid for electricity generation from 2026 to 2086. A total of 3148 spent nuclear fuel assemblies will be accumulated from WWER-440, which amounts to 362.649 t. Spent fuel from the WWER-440 will be removed after five years of storage in the reactor cooling pond.

The total accumulation of spent nuclear fuel assemblies from the WWER-1000 will be 1022.036 t (16.088 t × 59 years + 72.844 t). Fuel assemblies will be unloaded after 12 years of storage in the reactor cooling pool. The first group of fuel assemblies will be unloaded from cooling ponds in 2039, and the last one in 2099.

By 2100, 1 384.685 t of spent fuel will be accumulated from the WWER-440 and WWER-1000 nuclear units.

Figure 3.3 shows the accumulation of spent fuel over the planning period.

LUEC for the specified scenario is estimated at US $53.69/MW·h, and its structure is presented in Table 3.7.

TABLE 3.4. VALUE OF THE NUCLEAR FUEL PARAMETERS USED IN THE MODEL

Parameter WWER-440 WWER-1000 (new) WWER-1000 (old) VBER-300

Av. enrichment (%) 3.82 4.7 4.28 5

Burnup (MW·d/kg) 42.66 60.0 48.0 60.0

Weight of UO₂ in fuel assemblies (kg) 115.2 545 494 n.a.^a

Number of assemblies in the reactor (pcs) 349 163 163 n.a.^a

Fuel assemblies annual load (pcs) 78 36 42 n.a.^a

a n.a.: not applicable.

TABLE 3.5. VALUE OF PARAMETERS USED IN THE MODEL (US $/kg HM) Cost of spent fuel dry storage construction [3.8–3.11] 150 Cost of the geological disposal of spent fuel [3.8–3.12] 600 Cost of the processing without the return of

processing waste [3.13] 2000

TABLE 3.6. SPENT NUCLEAR FUEL MANAGEMENT CONFIGURATION OPTIONS

Configuration Option Comment

Management of SNF without construction

of small reactors Construction of SFDS at the NPP site (Reference Scenario)

Construction of SFDS at the NPP site and export of SNF from the NPP site to another country by rail for reprocessing and disposal of SNF after 50 years of storage at the NPP site

WWER-440

Fuel enrichment 3.82% Burnup 42.66 MW·d/t

SNF of WWER-440 is located in SFDS after the interim cooling in the cooling pool (5 years)

WWER-1000

Fuel enrichment 4.7% Burnup 60 MW·d/kg

SNF of WWER-1000 will be located in SFDS after the interim cooling in the cooling pool (12 years)

Operation time of SFDS is unlimited Volume of SFDS is limited by numbers of SNF assemblies of WWER-1000 and WWER-440

Construction of SFDS at the NPP site and transfer SNF to geological disposal after 50 years of SNF storage at the NPP site

Export of SNF from the NPP site to another country by different types

Removal after the interim storage of SNF in the cooling pool (5 years) and 50 years of storage in SFDS

Return of radioactive waste is not considered

Removal rate of SNF corresponds to the annual loading of the reactor(s) (or to the total annual load of the reactors) Construction of small reactors is envisaged

Export of SNF from the NPP site to another country by different types

Removal after the interim storage of SNF in the cooling pool (12 years) and 50 years of storage in SFDS

Return of radioactive waste is not considered

Removal rate of SNF corresponds to the annual loading of the reactor(s) (or to the total annual load of the reactors) Construction of small reactors is envisaged

Note: NPP — nuclear power plant; SFDS — spent fuel dry storage; SNF — spent nuclear fuel; WWER — water cooled, water moderated power reactor.

TABLE 3.4. VALUE OF THE NUCLEAR FUEL PARAMETERS USED IN THE MODEL

Parameter WWER-440 WWER-1000 (new) WWER-1000 (old) VBER-300

Av. enrichment (%) 3.82 4.7 4.28 5

Burnup (MW·d/kg) 42.66 60.0 48.0 60.0

Weight of UO₂ in fuel assemblies (kg) 115.2 545 494 n.a.^a

Number of assemblies in the reactor (pcs) 349 163 163 n.a.^a

Fuel assemblies annual load (pcs) 78 36 42 n.a.^a

a n.a.: not applicable.

TABLE 3.5. VALUE OF PARAMETERS USED IN THE MODEL (US $/kg HM) Cost of spent fuel dry storage construction [3.8–3.11] 150 Cost of the geological disposal of spent fuel [3.8–3.12] 600 Cost of the processing without the return of

processing waste [3.13] 2000

TABLE 3.6. SPENT NUCLEAR FUEL MANAGEMENT CONFIGURATION OPTIONS

Configuration Option Comment

Management of SNF without construction

of small reactors Construction of SFDS at the NPP site (Reference Scenario)

Construction of SFDS at the NPP site and export of SNF from the NPP site to another country by rail for reprocessing and disposal of SNF after 50 years of storage at the NPP site

WWER-440

Fuel enrichment 3.82%

Burnup 42.66 MW·d/t

SNF of WWER-440 is located in SFDS after the interim cooling in the cooling pool (5 years)

WWER-1000

Fuel enrichment 4.7%

Burnup 60 MW·d/kg

SNF of WWER-1000 will be located in SFDS after the interim cooling in the cooling pool (12 years)

Operation time of SFDS is unlimited Volume of SFDS is limited by numbers of SNF assemblies of WWER-1000 and WWER-440

Construction of SFDS at the NPP site and transfer SNF to geological disposal after 50 years of SNF storage at the NPP site

Export of SNF from the NPP site to another country by different types

Removal after the interim storage of SNF in the cooling pool (5 years) and 50 years of storage in SFDS

Return of radioactive waste is not considered

Removal rate of SNF corresponds to the annual loading of the reactor(s) (or to the total annual load of the reactors) Construction of small reactors is envisaged

Export of SNF from the NPP site to another country by different types

Removal after the interim storage of SNF in the cooling pool (12 years) and 50 years of storage in SFDS

Return of radioactive waste is not considered

Removal rate of SNF corresponds to the annual loading of the reactor(s) (or to the total annual load of the reactors) Construction of small reactors is envisaged

Note: NPP — nuclear power plant; SFDS — spent fuel dry storage; SNF — spent nuclear fuel; WWER — water cooled, water moderated power reactor.

(ii) Construction of the spent fuel dry storage and export of the spent fuel from the nuclear power plant site to another country

This scenario considers construction of spent fuel dry storage and subsequent export of spent fuel by railway transport. In this scenario, spent fuel export starts after its 50 years placement in dry storage. Figure 3.4 shows the dynamics of accumulation and removal of WWER-440 spent fuel from storage. It is assumed that 205.632 t of spent fuel accumulated before 2013 will be exported by 2063 (i.e. 50 years later). If the spent fuel is removed at a rate of 8.9856 t/year (an annual load of WWER-440), then the start of spent fuel removal produced until 2013 should be scheduled up to 2051.

Spent nuclear fuel from the WWER-440 — which will be transferred to spent fuel dry storage after 2013 — will begin to be exported in 2063 and will be completely removed by 2086 (see Fig. 3.4). The blue relates to the spent fuel from the WWER-440, which had accumulated before 2013; the brown is associated with spent fuel from the WWER-440, which will be produced after 2013. In total, 362.65 t of spent fuel will be produced.

TABLE 3.7. STRUCTURE OF THE LEVELIZED UNIT ENERGY COST

Cost component US $/MW·h

Investment cost 35.25

Fixed cost 9.25

Variable cost 0.81

Uranium cost 3.02

Conversion cost 0.21

Enrichment cost 3.22

Fabrication coat 1.71

Spent fuel management cost 0.23

Levelized unit energy cost 53.69

FIG. 3.3. Accumulation of spent fuel over the planning period.

FIG 3.4. Removal of WWER-440 spent fuel from spent fuel dry storage.

FIG. 3.5. Change of volume of WWER-1000 spent fuel in spent fuel dry storage.

The dynamics of accumulation and removal of spent fuel from the WWER-1000 are shown in Fig. 3.5. In consideration of the removal, 850 t of spent fuel will accumulated. Removal of spent fuel from the WWER-1000 will begin in 2089 (2027 + 12 + 50 years) and will be completed by 2152. Annual removal of spent fuel is limited by the amount of annual loading/unloading of WWER-1000 fuel, which is 16.088 t/year. The export of spent fuel from the WWER-1000 is shown in Fig. 3.6 In total, the WWER-1000 will produce 1022.036 t of spent fuel.

The LUEC for the specified scenario is estimated at US $53.82/MW h, and its structure is presented in Table 3.8.

TABLE 3.7. STRUCTURE OF THE LEVELIZED UNIT ENERGY COST

Cost component US $/MW·h

Investment cost 35.25

Fixed cost 9.25

Variable cost 0.81

Uranium cost 3.02

Conversion cost 0.21

Enrichment cost 3.22

Fabrication coat 1.71

Spent fuel management cost 0.23

Levelized unit energy cost 53.69

FIG. 3.3. Accumulation of spent fuel over the planning period.

FIG 3.4. Removal of WWER-440 spent fuel from spent fuel dry storage.

FIG. 3.5. Change of volume of WWER-1000 spent fuel in spent fuel dry storage.

(iii) Construction of the spent fuel dry storage and transfer of spent fuel to geological disposal

This scenario considers the construction of spent fuel dry storage from the WWER-440 and WWER-1000, as well as the construction of a geological repository for disposal of spent fuel. It is assumed that the spent fuel will initially be in spent fuel dry storage. After 50 years, the spent fuel will be transferred to a geological disposal.

The dynamics of the accumulation of WWER-440 spent fuel in centralized storage and the dynamics of spent fuel replacement into a geological repository are shown in Fig. 3.4. Accumulation of WWER-1000 spent fuel, and

TABLE 3.8. STRUCTURE OF THE LEVELIZED UNIT ENERGY COST

Cost component US $/MW·h

Investment cost 35.25

Fixed cost 9.25

Variable cost 0.81

Uranium cost 3.02

Conversion cost 0.21

Enrichment cost 3.22

Fabrication cost 1.71

Spent fuel management cost 0.23

Transfer cost 0.003 1

Cost of the processing without the return of

processing waste 0.12

Levelized unit energy cost 53.82

TABLE 3.9. STRUCTURE OF THE LEVELIZED UNIT ENERGY COST

Cost component US $/MW·h

Investment cost 35.25

Fixed cost 9.25

Variable cost 0.81

Uranium cost 3.02

Conversion cost 0.21

Enrichment cost 3.22

Fabrication cost 1.71

Spent fuel management cost 0.23

Disposal cost 0.04

Levelized unit energy cost 53.73

FIG. 3.6. Export dynamics of WWER-1000 spent fuel from spent fuel dry storage.

its removal and placement in a geological repository are shown in Figs 3.5 and 3.6. The LUEC for the specified scenario is estimated at US $53.73/MW·h, and its structure is presented in Table 3.9.

(c) Analysis of the results: Construction of small reactors, export of spent fuel from the nuclear power plant site to another country (old fuel modification)

This scenario considers the connection to the grid of WWER-1000 in 2026, as well as construction of a series of small VBER-300 reactors in 2035, 2045, 2055, 2065, 2075 and in 2095. The scenario considers the operation of the WWER-1000 reactor with fuel enrichment of 4.28% (old fuel modification). The structure of installed nuclear capacity and electricity generation until 2100 is shown in Figs 3.7 and 3.8. Total installed capacity in 2080 will increase to 2625 MW (1000 MW — WWER-1000 and 1625 MW — 5 × VBER-300).

Amounts of spent fuel are shown in Figs 3.9 and 3.10. Approximately 2376 t of spent fuel will be produced up to 2100. In total, there will be 1592 t of spent fuel in spent fuel dry storage collected from all the reactors considering the export of spent fuel (see Fig. 3.11). The spent fuel export rates from dry storage are taken at the level of annual loads for both WWER-440 and WWER-1000 reactors and the rate of export for small reactors is considered equal to spent fuel supply rate. Spent fuel exports for WWER-440 and WWER-1000 are limited by the number of annual loads for the corresponding reactors. The export of spent fuel from VBER-300 is determined by the volume of spent fuel unloaded from all reactors in a given year.

The export costs can be summarized as follows:

(i) Export by road: The cost of transporting spent fuel by road is set at US $112.5/kg HM. The LUEC will be

(i) Export by road: The cost of transporting spent fuel by road is set at US $112.5/kg HM. The LUEC will be

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