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Matsuo, Yoichiro; Hasegawa, Masanori; Maegawa, Yoshiharu; Miyahara, Shinya
Hoken Butsuri, 46(4), p.304 - 313, 2011/12
Radioactive corrosion products (CP) are main source of personal radiation exposure during maintenance without fuel-failure accident in the liquid-metal fast breeder reactor (LMFBR) plants. In order to establish the techniques of radiation dose estimation for personnel, program system DORE has been developed. The DORE system is constructed by PSYCHE code and QAD code system. The density of each deposited CP of primary coolant system in MONJU was estimated by using the PSYCHE. Moreover, the QAD-CGGP2R code is applied to dose rate calculations for the primary coolant system in MONJU. The predicted values were estimated to be saturated at 2-3 mSv/h in twenty years after the start of operation, and the dose rate reaches 4 mSv/h in domains near the IHX and the cold-leg piping.
Matsuo, Yoichiro; Hasegawa, Masanori; Maegawa, Yoshiharu; Miyahara, Shinya
Journal of Power and Energy Systems (Internet), 5(1), p.96 - 107, 2011/01
Radioactive corrosion products (CP) are primary cause of personal radiation exposure during maintenance work at FBR plants with no breached fuel. The PSYCHE code has been developed based on the solution-precipitation model for analysis of CP transfer behavior. We predicted and analyzed the CP solution and precipitation behavior of MONJU to evaluate the applicability of the PSYCHE code to MONJU, using the parameters verified in the calculations for JOYO. From the calculation result pertaining to the MONJU system, distribution of Mn deposited in the primary cooling system over 20 years of operation is predicted to be approximately 7 times larger than that of Co. In particular, predictions show a notable tendency for Mn precipitation to be distributed in the primary pump and cold-leg. The calculated distribution of Mn and Co in the primary cooling system of MONJU agreed with tendencies of measured distribution of JOYO.
Matsuo, Yoichiro; Hasegawa, Masanori; Maegawa, Yoshiharu; Miyahara, Shinya
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM), 8 Pages, 2010/05
Radioactive corrosion products are main cause of personal radiation exposure during maintenance with no breached fuel in FBR plants. CP is produced in the core region by activation of fuel cladding and sub-assembly wrappers, and they are transported to the primary circuit with sodium flow and deposited on the wall of the primary piping and components. In order to establish the techniques of radiation dose reduction for of personnel, program system for corrosion hazard evaluation code PSYCHE has been was developed. The PSYCHE code is based on the solution-precipitation model. The density of each deposited CP and dose rate of primary coolant system in Monju was estimated by using the PSYCHE and QAD-CG code.
Nishimura, Motohiko*; Nonaka, Yoshiharu*; Maekawa, Isamu*
JNC TJ9400 2005-002, 55 Pages, 2005/07
Sodium cooled FBR reactor in a feasibility study on commercialized fast reactor system has been designed so compact that flow velocity is much higher in the reactor than in the reactors so far. This design requires an evaluation method for gas entrainment from reactor free surface and effective countermeasures. Focusing on the establishment of gas entrainment evaluation method based on CFD, CFD simulation has been carried out with analyses of an existing gas entrainment experiment. In the analyses, four turbulence models such as standard k-e, RNG k-e, non-linear k-e and k-w have been applied and evaluated for their analytical capability in addition to laminar model. Main results have been obtained as follows;1) Laminar model shows faster vortices behavior accompanied with strong flow and pressure fluctuations including random variations than any other turbulence models. RNG model shows the solutions more similar to the laminar model than the other turbulence models.2) k-w, non-linear k-e and Standard k-e models show milder vortices behavior in this order due to excess turbulence viscosity.3) Main characteristics of major turbulence models have been obtained when they are applied to gas entrainment analysis.
Okubo, Seishiro; *; *; 2 of others*
PNC TN3410 88-010, 7 Pages, 1988/04
A study of chemical decontamination of the reactor cooling system of the Fugen has been made with KURIDECON 203, a dilute decontamination reagent. The heat exchangers of the cleanup water system and of the residual heat removal system were decontaminated with KD203. As a result, decontamination factor (DF) was about 20, and it has proved that chemical decontamination contributes to reduce the radioactive exposure.
Matsuo, Yoichiro; Hasegawa, Masanori; Maegawa, Yoshiharu; Miyahara, Shinya
no journal, ,
In order to reduce the personal radiation exposure during maintenance, the CPs transport behavior analysis code "PSYCHE" has been developed. The density of each deposited CP of primary coolant system in MONJU was estimated by using the PSYCHE. Moreover, the calculation result in the case that PNC and T-T equation for corrosion rate was compared. Our results suggest that the down stream effect was important in the cobalt type.
Kimura, Daisuke; Hikinuma, Yuichi; Tanabe, Masanori; Makino, Tatsuya; Maegawa, Yoshiharu; Hayata, Kenichi*; Shiotani, Junya*; Nohara, Naofumi; Hoshi, Katsuya; Tsujimura, Norio; et al.
no journal, ,
no abstracts in English