Achievement of Reactor-Outlet Coolant Temperature of 950°C in HTTR

Fujikawa, Seigo; Hayashi, Hideyuki; Nakazawa, T.; Kawasaki, Kozo; Iyoku, Tatsuo; Nakagawa, Shigeaki; Sakaba, Nariaki

doi:10.1080/18811248.2004.9726354

Cited by 114 publications

(34 citation statements)

References 2 publications

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“…The HTTR achieved criticality in November 1998 and has undergone a series of rise-to-power tests. 22 In December 2001, an outlet temperature of 850°C was achieved, and in April 2004 a temperature of 950°C was achieved. As of July 2004, the reactor had operated for 224 effective full-power days (EFPD).…”

Section: Leu Uo 2 Experience In Japanmentioning

confidence: 99%

“…The measured release-to-birth (R/B) of Kr-88 at full power, a 950qC outlet temperature, and approximately 200 EFPD of reactor operation was 1.0 × 10 -8 , corresponding to gaseous diffusion from HM contamination and no significant in-reactor fuel particle failures. 22 The high-temperature demonstration was maintained for about 5 days.…”

Section: Leu Uo 2 Experience In Japanmentioning

confidence: 99%

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NGNP Fuel Qualification White Paper

Petti¹

2010

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The Next Generation Nuclear Plant (NGNP) will be a licensed commercial high-temperature gas-cooled reactor (HTGR) plant capable of producing electricity and high-temperature process heat for industrial markets supporting a range of end-user applications. The NGNP Project has adopted the 10 CFR 52 Combined License (COL) application process, as recommended in the NGNP Licensing Strategy -Report to Congress, dated August 2008, as the foundation for the NGNP licensing strategy. The NGNP Project will be utilizing this NRC licensing process to demonstrate the efficacy of licensing future gas-cooled reactors for commercial industrial applications. This white paper is one in a series of submittals that will address key generic issues of the COL priority licensing topics as part of the process for establishing HTGR regulatory requirements.The NGNP Fuel Qualification White Paper summarizes the planned fuel qualification approach for the NGNP HTGR plants. The HTGR concepts under consideration include both pebble-bed and prismatic-block reactors. Both concepts employ tristructural-isotropic (TRISO) fuel particles, but the pebble-bed concept uses UO 2 (uranium oxide) fuel particles made into spheres, and the prismatic-block concept uses UCO (uranium oxycarbide) fuel particles made into cylindrical compacts that are then loaded into hexagonal-shaped graphite fuel blocks. The TRISO fuel particle consists of a microsphere (i.e., kernel) of nuclear material encapsulated by multiple layers of pyrocarbon and a SiC (silicon carbide) layer. This multiple-coating-layer system has been engineered to retain the fission products generated by fission of the nuclear material in the kernel during normal operation and all licensing basis events over the design lifetime of the fuel. Although plant safety depends on many factors, the TRISO-coated fuel is particularly critical to the safe operation of the reactor because the fuel particles are the primary (but not the only) barrier to fission-product release in HTGRs.The information in this paper provides the basis for interactions with Nuclear Regulatory Commission (NRC) staff. The NGNP Project wishes to obtain comments on the adequacy of the planned fuel qualification approach and feedback on a number of issues that can significantly impact the effort and schedule to prepare a combined license application (COLA) for the HTGR-based NGNP.vii viii

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Section: Leu Uo 2 Experience In Japanmentioning

confidence: 99%

Section: Leu Uo 2 Experience In Japanmentioning

confidence: 99%

NGNP Fuel Qualification White Paper

Petti¹

2010

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“…A few concerns, such as temperature anomalies, can be considered as lessons learned for NGNP. 10 Graphite oxidation was a concern at HTTR during the design (but never an operational problem) and should be an issue considered in NGNP design. Figure 9 A photo of the HTR-10 core is shown in , and a diagram of the primary circuit is shown in Figure 10.…”

Section: 46mentioning

confidence: 99%

“…The lithium in Peach Bottom was found to be one of the impurities in the radial reflectors. The tritium production from 10 B is dependent on the neutron energy. The tritium may migrate from the fuel and eventually into the purge gas flow, while tritium formed from the control rods and reflectors would pass directly into the gas flow.…”

Section: Fission Product Trapping (Peach Bottom Unit 1)mentioning

confidence: 99%

High Temperature Gas-Cooled Reactors Lessons Learned Applicable to the Next Generation Nuclear Plant

Beck¹,

Pincock²

2011

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“…Therefore, the HTGR can be considered a suitable energy source for producing a huge amount of hydrogen with no corresponding CO 2 emissions. Recently, aggressive research and development of HTGR designs have been carried out throughout the world (e.g., U.S.A. [Public Law 109-58 2005], France [Billot and Barbier 2004], South Africa [Matzner 2004], Republic of Korea [Shin et al 2005], China [Zhang and Yu 2002], and Japan [Fujikawa et al 2004]). …”

Section: Introductionmentioning

confidence: 99%

Tritium Movement and Accumulation in the NGNP System Interface and Hydrogen Plant

Ohashi¹,

Sherman²

2007

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Tritium movement and accumulation in a Next Generation Nuclear Plant with a hydrogen plant using a high-temperature electrolysis (HTE) process and a thermochemical water-splitting Sulfur-Iodine (SI) process are estimated by the numerical code THYTAN as a function of design, operational, and material parameters. Estimated tritium concentrations in the hydrogen product and in process chemicals in the hydrogen plant of the Next Generation Nuclear Plant using the HTE process are slightly higher than the drinking water limit defined by the U.S. Environmental Protection Agency and the limit in the effluent at the boundary of an unrestricted area of a nuclear plant as defined by the U.S. Nuclear Regulatory Commission. However, these concentrations can be reduced to within the limits through use of some designs and modified operations. Tritium concentrations in the Next Generation Nuclear Plant using the SI process are significantly higher as calculated and are affected by parameters with large uncertainties (i.e., tritium permeability of the process heat exchanger, the hydrogen concentration in the heat transfer and process fluids, the equilibrium constant of the isotope exchange reaction between HT and H 2 SO 4 ). These parameters, including tritium generation and the release rate in the reactor core, should be more accurately estimated in the near future to improve the calculations for the NGNP using the SI process. Decreasing the tritium permeation through the heat exchanger between the primary and secondary circuits may be an an effective measure for decreasing tritium concentrations in the hydrogen product, the hydrogen plant, and the tertiary coolant.iv v EXECUTIVE SUMMARYThis study evaluated tritium concentrations in the hydrogen product and in process chemicals in the energy transport systems and the hydrogen plant associated with the Next Generation Nuclear Plant (NGNP). In this work, tritium generation and transport mechansisms in the NGNP are described. The mathematics of these mechanisms are outlined, and are then codified and analyzed using a Japan Atomic Energy Agency (JAEA) analysis code called THYTAN [Tritium and HYdrogen Transportation ANalysis code ]. As a preliminary step, the THYTAN code was benchmarked against data available from the Peach Bottom HTGR. After benchmarking, various configurations of the NGNP employing a hightemperature electrolysis (HTE) hydrogen plant and an NGNP employing a Sulfur-Iodine (SI) hydrogen plant were analyzed, and the concentrations of tritium in the process and product streams were compared to current regulatory effluent limits in ground water and in air.Tritium is generated in the core of the reactor from the ternary fission of nuclear fuel (e.g., e.g., 233 B. Tritium from these reactions diffuses from the core materials into the primary coolant, where it can migrate to other parts of the system through bulk transport, diffusion, and isotope exchange mechanisms. Tritium is lost from the system when it diffuses through barrier materials to the outside environ...

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Achievement of Reactor-Outlet Coolant Temperature of 950°C in HTTR

Cited by 114 publications

References 2 publications

NGNP Fuel Qualification White Paper

NGNP Fuel Qualification White Paper

High Temperature Gas-Cooled Reactors Lessons Learned Applicable to the Next Generation Nuclear Plant

Tritium Movement and Accumulation in the NGNP System Interface and Hydrogen Plant

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