Towerd commercialization of FBR cycle

Nagata, Takashi; Mizuta, Shunji; Nagura, Fuminori

Enerugi Rebyu, 29(5), p.11 - 14, 2009/05

no abstracts in English

Research and development on next-generation reactor and related fuel cycle; Promotion of FBR cycle development for commercialization

Nagata, Takashi; Ichimiya, Masakazu; Funasaka, Hideyuki; Mizuta, Shunji; Nagura, Fuminori

Nihon Genshiryoku Gakkai-Shi ATOMO, 51(4), p.234 - 238, 2009/04

no abstracts in English

The Tentative Materials Strength Standard of ODS Ferritic Steel Claddings

Kaito, Takeji; Mizuta, Shunji; Uwaba, Tomoyuki; Otsuka, Satoshi; Ukai, Shigeharu

JNC TN9400 2005-015, 126 Pages, 2005/02

JNC-TN9400-2005-015.pdf:3.43MB

Oxide Dispersion Strengthened (ODS) ferritic steel has excellent swelling resistance and improved high-temperature strength, which are important properties for fast reactor fuel cladding tube. In feasibility study (FS) which is advanced by Japan Nuclear Cycle Development Institute (JNC), ODS ferritic steel is noticed as a prospective candidate material for commercialized fast reactor (FR) fuel cladding tube. JNC has developed a microstructure control procedure to disperse nano-sized oxide particles in equiaxed crystal grain and succeeded in producing high performance ODS ferritic steel tube, which has adequate mechanical properties. For the purpose of getting irradiation data base and evaluating applicability of ODS ferritic steel, fuel pin irradiation test of ODS ferritic steel cladding in FR such as JOYO is in the planning stage.This report describes a summary of the tentative materials strength standard of ODS ferritic steels for designing of FR fuel pin.

Development of ODS ferritic steel claddings

Mizuta, Shunji; Fujiwara, Masayuki;

JNC TN9400 2001-103, 139 Pages, 2001/09

JNC-TN9400-2001-103.pdf:7.93MB

Oxide dispersion strengthened (ODS) ferritic steels have been developing as a long life fuel claddings, because they are expected to be superior structure stability and high temperature strength up to high neutron dose. In order to improve a strength anisotropy induced by an elongated grain structure along rolling direction, the effects of manufacturing process and added elements have been studied by means of recrystallization technique. The feasibility study was also conducted for economical manufacturing process with capable of large scale production. Following results were obtained in this study. (1)From cold rolling manufacturing study as a parameter of Ti and YO contents, claddings have been successfully manufactured through softening by recrystallization heat treatment. The grains tend to elongate along rolling direction with increasing Ti and YO contents. (2)The ring tensile tests show the improved strength with increasing Ti and YO contents: 0.3Ti-0.23YO has the highest strength. The uniform elongation and ductility in circumferential direction is maintained at entire temperature range. (3)The internal creep rupture strength is also improved by finely distributed YO-TiO complex oxides. The manufactured cladding with 0.3Ti-0.23YO is expected to attain the target strength (120MPa at 700C for 10,000h). (4)At the cladding manufacturing test with four times rolling, recrystallization structure was realized at the final heat treatment by suppressing heat treatment temperature up to recovery stage at intermediate heat treatment.

Development of 14Cr-25Ni advanced austenitic steels(III); Out of piles tensile and thermal creep properties evaluation

Otsuka, Satoshi; Uwaba, Tomoyuki; ; Mizuta, Shunji

JNC TN9400 2001-038, 40 Pages, 2001/03

JNC-TN9400-2001-038.pdf:4.9MB

14Cr-25Ni advanced austenitic steels (14Cr-25Ni steel) was developed in order to improve the swelling resistance of modified 15Cr-20Ni base austenitic steels(PNC1520). This steel is planned to be utilized as back-up material for Monju advanced core component. Seven types of cladding tubes with different amounts of alloying elements of Ti, Nb, V and P had been fabricated and the out-of-pile testing of these cladding tubes has been conducted. Among out of piles properties, tensile property and creep property of 14Cr-25Ni steels were evaluated in this study. The results can be summarized as follows. (1)Tensile properties (0.2% yield stress, ultimate tensile strength, uniform elongation, ultimate elongation) of 14Cr-25Ni steels were almost equivalent to those of PNC316 steel and PNC1520 steel in the temperature range from room temp. to 900C. (2)The creep strength of 14Cr-25Ni steels was between PNC316 and PNC1520. It was shown that the long term creep strength at 750C was remarkably improved by the Ti, Nb and V addition. (3)It is suspected that the improvement of creep strength of V-added-steel would be caused by stabilization of dislocation microstructure due to finely distributed carbo-nitride [Ti, Nb, V(C, N)] precipitates.

Tenside Properties of 12% Cold Worked Type 316 Stalnless Steel Irradiated in EBR-2 under Lower -Dose-Rate Condition to High Fluence

Yoshitake, Tsunemitsu; Donomae, Takako; Mizuta, Shunji; James J.Co*

Progtams and Abstrac, p.469 - 486, 2001/00

None

Development of dissimilar welding technique between PNC-FMS wrapper tube and SUS316 steel (1); Investigation of ferrite formation and evaluation of charpy impact property

; Mizuta, Shunji;

JNC TN9400 2000-104, 132 Pages, 2000/10

JNC-TN9400-2000-104.pdf:10.02MB

Ferritic/Martensitic steel (PNC-FMS) with superior resistance to swelling is being developed as wrapper tube for the long-life core of large-scale fast breeder reacor. If the ferrite phase would be formed at heat affected zone(HAZ)in welding between PNC-FMS wrapper tube and SUS316 steel,and thus toughness degradation would be suspected due to ferrite formation. In this study, the formation of the ferrite in applying TIG welding and EB welding are investigated using base metal of 3 types, which are Ni max./Cr min., Ni min./Cr max. and the center of chemical composition in the specification. The effect of the amount of the ferrite formation and characteristics of toughness change with thermal aging were evaluated. The results are summarized as follows. (1)The ferrite generation can be suppressed in the combination of welding process and chemical composition. (a)In case of specification center, the ferrite formation can be suppressed about 1% by EB welding. (b)In case of Ni max./Cr min. in the specification, the ferrite formation can be perfectly suppressed even in TIG welding or EB welding.

The evaluation of material base standard of ODS ferritic stainless steel core component for fast breeder reactors

Mizuta, Shunji; ;

JNC TN9400 2000-048, 28 Pages, 2000/04

JNC-TN9400-2000-048.pdf:0.64MB

ODS (Oxide Dispersion Strengthened) ferritic-martainsitic steels are one of the most prospective cladding materials for advanced fast breeder reactors, since they are expected to have excellent swelling resistance and superior high temperature strength due to the finely distributed stable oxide particles(YO). Properties and the tentative strength equations for ODS ferritic-martainsitic were proposed on the basis of the latest data to apply to the feasibility study of the sodium coolant MOX fuel plant. The items of equations are follows. (1)creep rupture strength (2)correction factor of creep rupture strength (in Na and in reactor) (3)outer surface eorrosion (Na) (4)inner surface corrosion (in MOX fuel pin) (5)thermal conductivity

The survey and evaluation of oxidation for core material of the austenitic stainless steels in carbon dioxide gas-cooled reactor

Mizuta, Shunji; ;

JNC TN9400 2000-032, 38 Pages, 2000/03

JNC-TN9400-2000-032.pdf:1.2MB

lt is necessary for feasibility study of fast reactor to evaluate the oxidation of the austenitic stainless steels in the case of using for core material in carbon dioxide gas-cooled reactor. The properties for oxidation of austenitic stainless steels in carbon dioxide were surveyed in literatures and the data were selected after evaluation of factors for oxidation in carbon dioxide. The equation of oxidation in carbon dioxide for PE16, 20Cr/25Ni/Nb, 18Cr-8Ni and JNC Cladding materials were proposed. The equation for oxidation of austenitic stainless steels were expressed as upper limit for the equation according to parabolic law. The equation for JNC cladding materials (PNC316, PNC1520, 14Cr-25Ni) was proposed based the oxidation behavior of 18Cr-8Ni which is same oxidation region for weight gain in three-component system of Fe-Cr-Ni, in addition to evaluate of effect for silicon content. The oxidation equation of 20Cr/25Ni/Nb was applied to the high Ni alloy of JNC cladding material. The obtained equation is as follows, X = 4.4W1000, W = , kp = exp(-Q/(RT)), X: oxide thickness[m], W : weight gain[gcm], kp : parabolic rate constant[gcm s], t :time[sec] : constant[gcmS], Q : activation energy[J・mol], R : gas constant[8.314J K mol], T : temperature[K] (1) PE16 : kp = 1.09010 exp(-192,500/(RD)), (2) 20Cr/25Ni/Nb : kp = 1.65110 exp(-201,300/(RT)) High Ni alloy (JNC), (3)18Cr-8Ni : kp = 1.50310 exp(-60,000/(RT)), (4) PNC316, PNC1520 : kp = 1.50310 exp(-60,000/(RT))0.62 14Cr-25Ni(JNC) The weight gain is (3)(4)(2)(1) in order.

Irradiation creep of modified 316 and 15Cr-20Ni base austenitic S.S. fuel pins (MFA-1, 2) irradiated in FFTF

; ; Mizuta, Shunji

JNC TN9400 2000-023, 126 Pages, 2000/02

JNC-TN9400-2000-023.pdf:2.94MB

Modified 316 and 15Cr-20Ni base austenitic stainless steels had been developed by Japan Nuclear Cycle Development lnstitute as the candidate materials for Monju and Demonstration fast breeder reactor. Previously, irradiation creep correlation of modified 316 and 15Cr-20Ni had been evaluated using pressurized tubes irradiated in FFTF/MOTA. 0n the other hand, for other austenitic S.S. developed abroad, it was reported that irradiation creep behavior of fuel pin could not be sufficiently described using results of pressurized tube experiments. ln this study, irradiation creep properties of modified 316 and 15Cr-20Ni fuel pins (MFA-I, 2) irradiated in FFTF were evaluated. And irradiation deformation of MFA-1, 2 fuel pins were estimated using the irradiation creep correlation based on MOTA data. The results are summarized as follows : (1)Irradiation creep compliance B calculated from MFA-I, 2 data are 5.6 15.010 [(I0n/m, E>0.1Mev)(MPa)], Which are larger than B based on MOTA data of 2.26.410 and are within the range of B of other austenitic S.S. abroad. (2)Creep-swelling coupling coefficient D derived from MFA-1, 2 data tend to decrease with increasing swelling rate. And the range of D based on MFA-1, 2 data include values calculated from MOTA data of 3.88.210 [(MPa)] and for other austenitic S.S. abroad. (3)As the result that irradiation creep deformation of MFA-1, 2 fuel pins could be appropriately estimated using the irradiation creep correlation derived from MOTA data, it is considered that the creep, correlation based on MOTA data can be applied to estimation of fuel pin deformation.