- Email: [email protected]
Design optimization of ADS plant proposed by JAERI
ARTICLE IN PRESS
Nuclear Instruments and Methods in Physics Research A 562 (2006) 646–649 www.elsevier.com/locate/nima
Design optimization of ADS plant proposed by JAERI Shigeru Saitoa,, Kazufumi Tsujimotoa, Kenji Kikuchia, Yuji Kurataa, Toshinobu Sasaa, Makoto Umenoa, Kenji Nishiharaa, Motoharu Mizumotoa, Nobuo Ouchib, Hayanori Takeia, Hiroyuki Oigawaa a
JAERI, Nuclear Transmutation Gr., 2-4 Shirakata-shiraneTokai-mura Ibaraki-ken, 319-1195 Japan b JAERI, Accererator Gr., 2-4 Shirakata-shiraneTokai-mura Ibaraki-ken, 319-1195 Japan Available online 6 March 2006
Abstract JAERI is conducting R&D on the Accelerator Driven System (ADS) to transmute minor actinides (MAs). The present study discusses the design of the ADS plant and various R&D on the ADS. The reference design of ADS plant in JAERI is the 800 MW, Pb–Bi eutectic (LBE) cooled, tank-type subcritical reactor loaded with (MA+Pu) nitride fuel. LBE is selected as a spallation target material. In our results of the optimization study on the neutronics of the ADS, we have adopted the maximum multiplication factor (keff) of 0.97. From the results of thermal-hydraulic and structural analysis, the feasibility of the beam window was confirmed for steady state. The R&D activities in JAERI cover the development of superconducting proton linear accelerator, the LBE technology, the irradiation damages of materials, and the reactor physics of the subcritical reactor. r 2006 Elsevier B.V. All rights reserved. PACS: 25.40.Sc; 28.41.Ak; 28.41.Fr; 28.41.Kw; 28.50.Qd Keywords: ADS; Plant design; Transmutation of nuclear waste; MA; LBE; Spallation target; Subcritical reactor
1. Introduction
2. Design study of 800 MW th ADS plant
The Japan Atomic Energy Research Institute (JAERI) is conducting research and development (R&D) on the Accelerator Driven System (ADS) to transmute the miner actinide (MA) [1,2]. The ADS has potential advantages in comparison with critical reactors: (1) various fuel composition is flexibly acceptable since the Doppler effect does not seriously affect the system safety, and (2) small value of delayed neutron fraction is also acceptable since the margin to the prompt critical state can be kept by the subcriticality. The ADS is, therefore, considered suitable to transmute the MA for various scenarios of nuclear power generation. This fact means that the ADS can be deployed under various conditions in many countries. The present study discusses the design of the ADS plant and various R&D on the ADS.
The reference ADS design proposed by JAERI [3,4] is the 800 MW, Pb–Bi eutectic (LBE) cooled, tank-type subcritical reactor loaded with (MA+Pu) nitride fuel, and driven by the spallation neutron source using LBE target and proton accelerator as shown in Fig. 1. In the ADS, 250 kg of MA can be burned per year by fission reactions, which corresponds to the amount of MA produced in 10 units of LWRs whose burn-up is 33,000 MWD/t.
Corresponding author. Tel.: +81 29 282 5058; fax: +81 29 282 6489.
E-mail address: [email protected] (S. Saito). 0168-9002/$ - see front matter r 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.nima.2006.02.078
2.1. Neutronics design To optimize the neutronics design of ADS, the following critical points should be considered; (1) reduction of the power peaking factor, (2) reduction of the beam intensity, (3) reduction of the burn-up reactivity swing, (4) maximization of the transmutation rate. It is important that these critical points should be optimized throughout the
ARTICLE IN PRESS S. Saito et al. / Nuclear Instruments and Methods in Physics Research A 562 (2006) 646–649
647
470.0 450.0 200.5
(2 03
IR
R) O
0.0
(176.7)
5
20
8 .9
3.0
2.0
60°
319.7
(1.985)
435.5 OR 432. 5 IR
Fig. 2. Design of the beam window.
Fig. 1. Conceptual design of 800 MW ADS plants. Table 1 Core physics parameters of 800 MW ADS Parameters
Values
Thermal power Cycle length Inert matrix (ZrN) Initial Pu (inner/outer) Total heavy metal inventory Initial MA inventory Effective multiplication factor (keff) Burn-up reactivity swing Peaking factor (whole core) Average power density Proton beam energy Proton beam current
800 MW 600 EFPD1 49.9% 30.0%/48.5% 4,115 kg 2,500 kg Initial: 0.970 Max.: 0.970, Min.: 0.940 3.01% Dk/k Max.: 2.52, Min.: 1.70 191 W/cm3 1.5 GeV Max.: 17.9 mA, Min.: 8.1 mA
1
Effective full power days.
whole fuel cycle. Our recent results of the optimization study on the neutronics of the ADS are described in Ref. [3] and core physics parameters are listed in Table 1. We had adopted the maximum multiplication factor (keff) of 0.97. 2.2. Thermal hydraulic and structure design of ADS In terms of thermal-hydraulic and structural design, the critical issues of ADS design are in the engineering
feasibility of the beam window for the high power spallation target and cooling performance of the hot spot fuel pin. Preliminary results of the analysis in JAERI are described below. To discuss the feasibility of beam window for steady state, two target criteria were set regarding the thermalhydraulics: (1) flow speed of LBE should not exceed 2 m/s, (2) outer surface temperature of beam window should not exceed 520 1C. To satisfy these conditions, some design modifications were adopted [5] and shown in Fig. 2. From the results of thermal-hydraulic and structural analysis, the feasibility of the beam window was confirmed for steady state. Feasibility of the beam window was also discussed for transient conditions: (1) 5 s beam trip, and (2) pump trip with flow-halving time of 5 s and beam trip after 2 and (3) drift of proton beam center up to 50 mm. As a beam window material, 9Cr-1Mo steel was selected. Thermalhydraulic analysis and structural analysis were carried out. In case (1), thermal stress will be at maximum after 0.5 s. from the beam trip. The buckling strength at the moment will be over three times larger than the assumed external pressure of 0.8 MPa. The allowable number of cycles for the stress is over 105 cycles, while the number of beam trips is assumed to be about 50 times/year. In case (2), thermal stress will be at maximum after 2.4 s. from the pump trip. The buckling stress at the moment of the 2.0 mm thick beam window will be over three times larger than the assumed external pressure. The assumed number of pump trips of 12 times/year is smaller than the allowable number of cycles over 105. In case (3), it was found that beam drift should be limited within 20 mm, because maximum temperature around the welded potion of the beam duct will be too high to maintain an integrity and
ARTICLE IN PRESS 648
S. Saito et al. / Nuclear Instruments and Methods in Physics Research A 562 (2006) 646–649
inhomogeneous temperature distribution will cause a deformation of the beam window. As for the cooling performance of the core, four targeted criteria were set: (1) maximum outer surface temperature of fuel claddings should not exceed 600 1C, (2) flow speed of LBE should not exceed 2 m/s, (3) the inlet temperature of LBE coolant should be higher than 300 1C, and (4) the difference between inlet and outlet temperatures of LBE coolant should be larger than 100 1C. To satisfy these criteria at the hot spot pin, the pin diameter was selected as 7.65 mm. Flow rate distribution among the active core fuel assemblies is not adopted because of the ductless assemblies. In consequence, the maximum temperature of the claddings became about 600 1C. 2.3. Preliminary safety analysis Preliminary safety analyses for typical initiator were carried out. Criteria for integrity were as follows; (1) fuel temp. p2700 1C, (2) clad temp. p1150 1C, (3) cumulative damage fraction (CFD) p0.5 and (4) coolant boundary temp. p650 1C. From the results of analyses, it was found that Loss of Flow (LOF) with a beam-on situation is the most severe initiator for the ADS. For instance, when flowhalving time of pump coast down is 5 s, buckling of the beam window and failure of fuel pin will occur within 11 s and 16 s, respectively, after the flow coast down. At the Transient Over Power (TOP) accident in which beam current was rapidly doubled, all conditions were met for criteria during the accident, though, margin for the criteria is very small. At the Loss of Heat Sink (LOHS) accident with a beam-on situation, coolant boundary temperature reached 650 1C after 460 s.
characteristics were measured for the hemispherical shape beam window. In the field of the reactor physics of the sub critical core, the reliability of nuclear data was examined, and the subcriticality monitoring technique was investigated in JAERI and university as a joint research. 4. Conclusion The JAERI has been conducting the study on the dedicated transmutation system using the ADS. The design study is under way on LBE-cooled, tank-type, ADS with the thermal power of 800 MW. By the optimization design study from neutronics, thermal-hydraulic and structural aspects, feasibility of the beam window for steady state and transient conditions was established, though further investigation is still necessary. Preliminary safety analyses for the ADS were carried out for typical initiator. It was found that LOF with a beam-on situation is the most severe initiator for the ADS. Beam stop should be done within 10 s. to maintain integrity of the core components. Many R&D activities are under way and planned in parallel at JAERI to examine the feasibility of ADS. In the field of proton accelerator, SC-LINAC is being developed. In the field of LBE technology, material compatibility, thermal-hydraulics, irradiation effect and polonium behavior are being studied. In the field of the reactor physics of the sub-critical core, the reliability of nuclear data was examined, and the subcriticality monitoring technique was investigated. The results of the above mentioned R&D will be reflected to the ADS plant design activity. Acknowledgments
3. R&D activities on ADS Many R&D activities are under way and planned in parallel at JAERI to examine the feasibility of ADS. In the field of proton accelerator, the super-conducting linear accelerator (SC-LINAC) is being developed in JAERI [6]. In addition, JAERI has started the J-PARC (Japan Proton Accelerator Complex) project with the High Energy Accelerator Research Organization (KEK) [7]. In the second phase of this project, SC-LINAC will be constructed to upgrade the proton energy from 400 to 600 MeV. In the field of LBE technology, material compatibility in the static [8–10] and flowing [11,12] LBE, the irradiation effect by protons and neutrons on the structural material [13–15] and polonium behavior [16,17] are being studied. To investigate the prediction accuracy of heat transfer coefficients at the beam window, JAERI and Mitsui Engineering and Shipbuilding (MES) built a thermal-hydraulic loop (JLBL-3) at the Tokai Establishment of JAERI as a joint research. The heat transfer
A part of this work was funded by the MEXT (Ministry of Education, Culture, Sports, Science and Technology). References [1] [2] [3] [4]
[5]
[6]
[7] [8] [9] [10] [11]
H. Takano, et al., Prog. Nucl. Energy 37 (2000) 371. T. Mukaiyama, et al., Prog. Nucl. Energy 38 (2001) 107. K. Tsujimoto, et al., J. Nucl. Sci. Technol. 41 (2004) 21. H. Oigawa, et al., Proceedings of OECD/NEA eighth Information Exchange Meeting on Actinide and Fission Product Partitioning andTransmutation, 2004. H. Oigawa, et al., Proceedings of fourth International Workshop on the Utilization and Reliability of High Power Proton Accelerators, HPPA2004, May 2004, Korea 2004. N. Ouchi, Third International Workshop on the Utilization and Reliability of High Power Proton Accelerators, HPPA2002, 12–16 May 2002, Santa Fe, USA 2002. The Joint Project Team of JAERI and KEK, JAERI-Tech 99-056 (KEK Report 99-4, JHF-99-3), 1999. Y. Kurata, et al., J. Nucl. Mater. 301 (2002) 28. Y. Kurata, et al., FZKA 6876 (2003) 190. Y. Kurata, et al., J. Nucl. Mater. 343 (2005) 333. K. Kikuchi, et al., J. Nucl. Mater. 318 (2003) 348.
ARTICLE IN PRESS S. Saito et al. / Nuclear Instruments and Methods in Physics Research A 562 (2006) 646–649 [12] K. Kikuchi, et al., JSME Internatinal Journal Section B 47 (2004) 332. [13] K. Kikuchi, et al., Proceedings of the Accelerator Applications in a Nuclear Renaissance (AccApp’03), San Diego, Cal. 2003. 874.
649
[14] S. Saito, et al., J. Nucl. Mater. 343 (2005) 253. [15] S. Saito, et al., J. Nucl. Mater. 329–333 (2004) 1093. [16] S. Ohno, et al., Proceedings of 12th International Conference on Nuclear Engineering (ICONE-12), 2004. [17] S. Ohno, et al., J. Nucl. Sci. Technol. 42 (2005) 593.
Nuclear Instruments and Methods in Physics Research A 562 (2006) 646–649 www.elsevier.com/locate/nima
Design optimization of ADS plant proposed by JAERI Shigeru Saitoa,, Kazufumi Tsujimotoa, Kenji Kikuchia, Yuji Kurataa, Toshinobu Sasaa, Makoto Umenoa, Kenji Nishiharaa, Motoharu Mizumotoa, Nobuo Ouchib, Hayanori Takeia, Hiroyuki Oigawaa a
JAERI, Nuclear Transmutation Gr., 2-4 Shirakata-shiraneTokai-mura Ibaraki-ken, 319-1195 Japan b JAERI, Accererator Gr., 2-4 Shirakata-shiraneTokai-mura Ibaraki-ken, 319-1195 Japan Available online 6 March 2006
Abstract JAERI is conducting R&D on the Accelerator Driven System (ADS) to transmute minor actinides (MAs). The present study discusses the design of the ADS plant and various R&D on the ADS. The reference design of ADS plant in JAERI is the 800 MW, Pb–Bi eutectic (LBE) cooled, tank-type subcritical reactor loaded with (MA+Pu) nitride fuel. LBE is selected as a spallation target material. In our results of the optimization study on the neutronics of the ADS, we have adopted the maximum multiplication factor (keff) of 0.97. From the results of thermal-hydraulic and structural analysis, the feasibility of the beam window was confirmed for steady state. The R&D activities in JAERI cover the development of superconducting proton linear accelerator, the LBE technology, the irradiation damages of materials, and the reactor physics of the subcritical reactor. r 2006 Elsevier B.V. All rights reserved. PACS: 25.40.Sc; 28.41.Ak; 28.41.Fr; 28.41.Kw; 28.50.Qd Keywords: ADS; Plant design; Transmutation of nuclear waste; MA; LBE; Spallation target; Subcritical reactor
1. Introduction
2. Design study of 800 MW th ADS plant
The Japan Atomic Energy Research Institute (JAERI) is conducting research and development (R&D) on the Accelerator Driven System (ADS) to transmute the miner actinide (MA) [1,2]. The ADS has potential advantages in comparison with critical reactors: (1) various fuel composition is flexibly acceptable since the Doppler effect does not seriously affect the system safety, and (2) small value of delayed neutron fraction is also acceptable since the margin to the prompt critical state can be kept by the subcriticality. The ADS is, therefore, considered suitable to transmute the MA for various scenarios of nuclear power generation. This fact means that the ADS can be deployed under various conditions in many countries. The present study discusses the design of the ADS plant and various R&D on the ADS.
The reference ADS design proposed by JAERI [3,4] is the 800 MW, Pb–Bi eutectic (LBE) cooled, tank-type subcritical reactor loaded with (MA+Pu) nitride fuel, and driven by the spallation neutron source using LBE target and proton accelerator as shown in Fig. 1. In the ADS, 250 kg of MA can be burned per year by fission reactions, which corresponds to the amount of MA produced in 10 units of LWRs whose burn-up is 33,000 MWD/t.
Corresponding author. Tel.: +81 29 282 5058; fax: +81 29 282 6489.
E-mail address: [email protected] (S. Saito). 0168-9002/$ - see front matter r 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.nima.2006.02.078
2.1. Neutronics design To optimize the neutronics design of ADS, the following critical points should be considered; (1) reduction of the power peaking factor, (2) reduction of the beam intensity, (3) reduction of the burn-up reactivity swing, (4) maximization of the transmutation rate. It is important that these critical points should be optimized throughout the
ARTICLE IN PRESS S. Saito et al. / Nuclear Instruments and Methods in Physics Research A 562 (2006) 646–649
647
470.0 450.0 200.5
(2 03
IR
R) O
0.0
(176.7)
5
20
8 .9
3.0
2.0
60°
319.7
(1.985)
435.5 OR 432. 5 IR
Fig. 2. Design of the beam window.
Fig. 1. Conceptual design of 800 MW ADS plants. Table 1 Core physics parameters of 800 MW ADS Parameters
Values
Thermal power Cycle length Inert matrix (ZrN) Initial Pu (inner/outer) Total heavy metal inventory Initial MA inventory Effective multiplication factor (keff) Burn-up reactivity swing Peaking factor (whole core) Average power density Proton beam energy Proton beam current
800 MW 600 EFPD1 49.9% 30.0%/48.5% 4,115 kg 2,500 kg Initial: 0.970 Max.: 0.970, Min.: 0.940 3.01% Dk/k Max.: 2.52, Min.: 1.70 191 W/cm3 1.5 GeV Max.: 17.9 mA, Min.: 8.1 mA
1
Effective full power days.
whole fuel cycle. Our recent results of the optimization study on the neutronics of the ADS are described in Ref. [3] and core physics parameters are listed in Table 1. We had adopted the maximum multiplication factor (keff) of 0.97. 2.2. Thermal hydraulic and structure design of ADS In terms of thermal-hydraulic and structural design, the critical issues of ADS design are in the engineering
feasibility of the beam window for the high power spallation target and cooling performance of the hot spot fuel pin. Preliminary results of the analysis in JAERI are described below. To discuss the feasibility of beam window for steady state, two target criteria were set regarding the thermalhydraulics: (1) flow speed of LBE should not exceed 2 m/s, (2) outer surface temperature of beam window should not exceed 520 1C. To satisfy these conditions, some design modifications were adopted [5] and shown in Fig. 2. From the results of thermal-hydraulic and structural analysis, the feasibility of the beam window was confirmed for steady state. Feasibility of the beam window was also discussed for transient conditions: (1) 5 s beam trip, and (2) pump trip with flow-halving time of 5 s and beam trip after 2 and (3) drift of proton beam center up to 50 mm. As a beam window material, 9Cr-1Mo steel was selected. Thermalhydraulic analysis and structural analysis were carried out. In case (1), thermal stress will be at maximum after 0.5 s. from the beam trip. The buckling strength at the moment will be over three times larger than the assumed external pressure of 0.8 MPa. The allowable number of cycles for the stress is over 105 cycles, while the number of beam trips is assumed to be about 50 times/year. In case (2), thermal stress will be at maximum after 2.4 s. from the pump trip. The buckling stress at the moment of the 2.0 mm thick beam window will be over three times larger than the assumed external pressure. The assumed number of pump trips of 12 times/year is smaller than the allowable number of cycles over 105. In case (3), it was found that beam drift should be limited within 20 mm, because maximum temperature around the welded potion of the beam duct will be too high to maintain an integrity and
ARTICLE IN PRESS 648
S. Saito et al. / Nuclear Instruments and Methods in Physics Research A 562 (2006) 646–649
inhomogeneous temperature distribution will cause a deformation of the beam window. As for the cooling performance of the core, four targeted criteria were set: (1) maximum outer surface temperature of fuel claddings should not exceed 600 1C, (2) flow speed of LBE should not exceed 2 m/s, (3) the inlet temperature of LBE coolant should be higher than 300 1C, and (4) the difference between inlet and outlet temperatures of LBE coolant should be larger than 100 1C. To satisfy these criteria at the hot spot pin, the pin diameter was selected as 7.65 mm. Flow rate distribution among the active core fuel assemblies is not adopted because of the ductless assemblies. In consequence, the maximum temperature of the claddings became about 600 1C. 2.3. Preliminary safety analysis Preliminary safety analyses for typical initiator were carried out. Criteria for integrity were as follows; (1) fuel temp. p2700 1C, (2) clad temp. p1150 1C, (3) cumulative damage fraction (CFD) p0.5 and (4) coolant boundary temp. p650 1C. From the results of analyses, it was found that Loss of Flow (LOF) with a beam-on situation is the most severe initiator for the ADS. For instance, when flowhalving time of pump coast down is 5 s, buckling of the beam window and failure of fuel pin will occur within 11 s and 16 s, respectively, after the flow coast down. At the Transient Over Power (TOP) accident in which beam current was rapidly doubled, all conditions were met for criteria during the accident, though, margin for the criteria is very small. At the Loss of Heat Sink (LOHS) accident with a beam-on situation, coolant boundary temperature reached 650 1C after 460 s.
characteristics were measured for the hemispherical shape beam window. In the field of the reactor physics of the sub critical core, the reliability of nuclear data was examined, and the subcriticality monitoring technique was investigated in JAERI and university as a joint research. 4. Conclusion The JAERI has been conducting the study on the dedicated transmutation system using the ADS. The design study is under way on LBE-cooled, tank-type, ADS with the thermal power of 800 MW. By the optimization design study from neutronics, thermal-hydraulic and structural aspects, feasibility of the beam window for steady state and transient conditions was established, though further investigation is still necessary. Preliminary safety analyses for the ADS were carried out for typical initiator. It was found that LOF with a beam-on situation is the most severe initiator for the ADS. Beam stop should be done within 10 s. to maintain integrity of the core components. Many R&D activities are under way and planned in parallel at JAERI to examine the feasibility of ADS. In the field of proton accelerator, SC-LINAC is being developed. In the field of LBE technology, material compatibility, thermal-hydraulics, irradiation effect and polonium behavior are being studied. In the field of the reactor physics of the sub-critical core, the reliability of nuclear data was examined, and the subcriticality monitoring technique was investigated. The results of the above mentioned R&D will be reflected to the ADS plant design activity. Acknowledgments
3. R&D activities on ADS Many R&D activities are under way and planned in parallel at JAERI to examine the feasibility of ADS. In the field of proton accelerator, the super-conducting linear accelerator (SC-LINAC) is being developed in JAERI [6]. In addition, JAERI has started the J-PARC (Japan Proton Accelerator Complex) project with the High Energy Accelerator Research Organization (KEK) [7]. In the second phase of this project, SC-LINAC will be constructed to upgrade the proton energy from 400 to 600 MeV. In the field of LBE technology, material compatibility in the static [8–10] and flowing [11,12] LBE, the irradiation effect by protons and neutrons on the structural material [13–15] and polonium behavior [16,17] are being studied. To investigate the prediction accuracy of heat transfer coefficients at the beam window, JAERI and Mitsui Engineering and Shipbuilding (MES) built a thermal-hydraulic loop (JLBL-3) at the Tokai Establishment of JAERI as a joint research. The heat transfer
A part of this work was funded by the MEXT (Ministry of Education, Culture, Sports, Science and Technology). References [1] [2] [3] [4]
[5]
[6]
[7] [8] [9] [10] [11]
H. Takano, et al., Prog. Nucl. Energy 37 (2000) 371. T. Mukaiyama, et al., Prog. Nucl. Energy 38 (2001) 107. K. Tsujimoto, et al., J. Nucl. Sci. Technol. 41 (2004) 21. H. Oigawa, et al., Proceedings of OECD/NEA eighth Information Exchange Meeting on Actinide and Fission Product Partitioning andTransmutation, 2004. H. Oigawa, et al., Proceedings of fourth International Workshop on the Utilization and Reliability of High Power Proton Accelerators, HPPA2004, May 2004, Korea 2004. N. Ouchi, Third International Workshop on the Utilization and Reliability of High Power Proton Accelerators, HPPA2002, 12–16 May 2002, Santa Fe, USA 2002. The Joint Project Team of JAERI and KEK, JAERI-Tech 99-056 (KEK Report 99-4, JHF-99-3), 1999. Y. Kurata, et al., J. Nucl. Mater. 301 (2002) 28. Y. Kurata, et al., FZKA 6876 (2003) 190. Y. Kurata, et al., J. Nucl. Mater. 343 (2005) 333. K. Kikuchi, et al., J. Nucl. Mater. 318 (2003) 348.
ARTICLE IN PRESS S. Saito et al. / Nuclear Instruments and Methods in Physics Research A 562 (2006) 646–649 [12] K. Kikuchi, et al., JSME Internatinal Journal Section B 47 (2004) 332. [13] K. Kikuchi, et al., Proceedings of the Accelerator Applications in a Nuclear Renaissance (AccApp’03), San Diego, Cal. 2003. 874.
649
[14] S. Saito, et al., J. Nucl. Mater. 343 (2005) 253. [15] S. Saito, et al., J. Nucl. Mater. 329–333 (2004) 1093. [16] S. Ohno, et al., Proceedings of 12th International Conference on Nuclear Engineering (ICONE-12), 2004. [17] S. Ohno, et al., J. Nucl. Sci. Technol. 42 (2005) 593.