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Takeda, Toshikazu*; Hazama, Taira; Fujimura, Koji*; Sawada, Shusaku*
Proceedings of International Conference on the Physics of Reactors; The Role of Reactor Physics toward a Sustainable Future (PHYSOR 2014) (CD-ROM), 15 Pages, 2014/09
A national project started in 2013 in Japan entitled "technology development for the environmental burden reduction". The present study is one of the studies adopted as the national project. We are aiming to develop MA transmutation core concepts harmonizing MA transmutation performance with core safety and to improve design accuracy related to MA transmutation performance. To validate and improve design accuracy of the high safety and high MA transmutation performance of SFR cores, we develop methods for calculating the transmutation rate of individual MA nuclides and estimating uncertainty of MA transmutation by using burnup sensitivity. Also we develop reliable reactor physics database to reduce the uncertainty of MA transmutation calculations. The overall consistency of the measured data is investigated by evaluating the usefulness of conventional static data as well as those related to MA transmutation obtained from various facilities like Monju, Joyo, FCA, BFS and PFR.
Chikazawa, Yoshitaka; Kotake, Shoji; Sawada, Shusaku*
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles (FR 2009) (CD-ROM), 12 Pages, 2012/00
Chikazawa, Yoshitaka; Kotake, Shoji; Sawada, Shusaku*
Nuclear Engineering and Design, 241(1), p.378 - 385, 2011/01
Times Cited Count：4 Percentile：32.59(Nuclear Science & Technology)*; Sawada, Shusaku*; *; *; *
JNC TJ9400 2001-011, 159 Pages, 2001/03
JNC-TJ9400-2001-011.pdf:5.21MB
In order to improve the reliability of safety system of FBR employing passive safety functions, requirements on a self-actuated shutdown system (SASS) have been summarized, which employs Curie-point magnets in its safety rods, for a large homogeneous reactor core (1500MWe), which was designed by JNC in JFY1999 as one of candidates in the Feasibility Studies on Commercialized FBR System. The requirements were based on the sensitivity analyses, conducted by using the safety analysis code SAS4A, of uncertainty factors that affect the maximum coolant temperature in unprotected loss-of-flow events. The study has given the following requirements: (1)The detachment temperature of the SASS magnet is to be set above 638
C (911K) to avoid the possibility of unintended rod drop under normal operations, and to be set below 666C (939K) to prevent coolant boiling under ULOF conditions conservatively assuming a boiling temperature of 960C in the plant. (2)The parameter that has the largest sensitivity on the maximum coolant temperature under ULOF conditions is the exit coolant temperatures of the adjacent fuel assemblies to the SASS assembly, with a sensitivity coefficient of 20.5C/
(1= 6.7C for the exit coolant temperature). It has been concluded based on the parametric analyses that a SASS design even with a nominal detachment temperature of 666C, the SASS has a safety margin of about 3.4 for the exit coolant temperature of the most sensitive adjacent fuel assembly in preventing coolant boiling under ULOF conditions, if the incoherency of SASS detachments are appropriately taken into account together with a more realistic criterion on the coolant boiling temperature (1018C) under the ULOF conditions of this plant.
Sawada, Shusaku*; *; *
PNC TJ9124 91-002, 331 Pages, 1991/03
"HIBEACON", which is a three dimensional core deformation analysis code for the experimental fast reactor "JOYO", had been modified in order to expand the code's functions for planning a long-term operation and managing the operation of "JOYO", and to analyse the core deformation characteristics speedily and accurately. In this study, "HITETRAS", which is a code for calculating temperatures and fast neutron fluxes on wrapper tubes, has been modified in order for it to correspond with the modification of "HIBEACON". And, the core deformation analysis on "JOYO" MK-III has been performed with those modified codes. Results of this study are as follows: (1) Improvement of core deformation analysis code. (a) Modification of function of "HITETRAS" to output temperatures and neutron fluxes. The method to output wrapper tubes' temperatures and neutron fluxes has been modified corresponding to the modification of "HIBEACON". (b) Addition of ability to alter program size of "HITETRAS". An ability to alter the program size has been added to "HITETRAS" by using INCLUDE statement and PARAMETER statement of FORTRAN language. (c) Modification of "HIBEACON". Following modifications, which are required for analysis on "JOYO" MK-III, have been perfomed. (1) alteration of calculation method for gap clearance between wrapper tubes. (2) addition of function for outputting elements of free bowing deformation (3) addition of function for selecting items to be output on list (2) Core deformation analysis on "JOYO" MK-III. "JOYO" MK-III will have different core characteristics from MK-II because of its higer neutron flux feature, two core regions, wider irradiation space, and so on. So, the core deformation behavior of "JOYO" MK-III has been analysed with the modified codes above-mentioned, and it has been clarified that there is no problem on the core integrity of MK-III from the view point of the core deformation.
Sawada, Shusaku*; *; *
PNC TJ9124 88-007, 173 Pages, 1988/05
Following functions have been added to HIBEACON which is a three dimensional core deformation analysis code for experimental fast reactor "JOYO", in order to improve the functions for evaluation of core deformation behavior and calculational accuracy of the code. (1)Calculational model for frictional force at contact points between wrappers. (2)Function to assign swelling and creeping equations to each core element's type. The Characteristics of this code are as follows, (i)Sliding events and sticking events in the frictional phenomenon can be calculated with HIBEACON's characteristic being kept, which is to decompose a core element's displacement into components in three directions. (ii)It's supposed that a sliding event proceeds in quasi-static and a static frictional force at end of a sliding event is equal to a dynamic frictional force just before the end. (iii)The frictional force at a sticking event can be treated as an internal force in a contact point with the condition that there is no relative displacement between two assemblies which contact each other through a sticking contact point. (iv)Damping method is adopted at the process of frictional force calculation in order to stabilize a solution of frictional force in sliding event. (v)A calculational method of repetition is adopted at the process of frictional force calculation. The results during repetition can be obtained in the form of output lists and plotter at option. (vi)Swelling and creeping equations can be assigned to each core element's type and the maximum number of core element's types has been increased from six to fifteen. (vii)Core deformation behavior at several points of the process of power descent can be calculated as well as the process of power ascent. The example-4, which is one of the benchmark problems submitted by IAEA/IWGFR, is calculated with this modified code. Following results on the influence of friction to deformation behavior has been obtained, (i)The ...
Sawada, Shusaku*; *; *
PNC TJ9124 88-006, 80 Pages, 1988/05
Following Functions have been added to HIBEACON which is a three dimensional core deformation analysis code for experimental fast reactor "JOYO", in order to improve output file compilation. (1)Function to calculate and output core element's axial distortion. The function to calculate and output core element's axial distortion due to thermal and swelling expansion has been added to HIBEACON. (2)Function to calculate and output force to pull core element from core. The function to calculate and output force to pull core element from core has been added. The force, which is required initially when a core element is pulled from core, is calculated using contact forces at load pads, upper and lower parts of entrance nozzle and coefficients of friction.
