Kobayashi, Tetsuya; Araki, Masaaki; Oba, Toshinobu; Torii, Yoshiya; Takeuchi, Masaki*
JAEA-Conf 2011-003, p.83 - 86, 2012/03
Kishi, Toshiaki; Motohashi, Jun; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Torii, Yoshiya
JAEA-Technology 2008-054, 99 Pages, 2008/08
JRR-4 had carried out modification works for the purpose of reducing the enrichment level of fuel. About utilization facilities, followings were installed new neutron beam facility, renewal irradiation facility that was modified pneumatic irradiation facility for activation analysis of short-lived nuclides. This report describes the characteristic measurement by initial core and equilibrium core in 2001 by renewal JRR-4. Utilization facilities had been identified equal performance before modify about neutron flux and cadmium ratio on 1998 and 2001. And we have achieved less than 5% of irradiation uniformity at N-pipe. The maximum neutron flux is about 2.210ms at the New neutron beam facility and the maximum neutron flux is about 110ms at the prompt -ray analysis facility got good quality performance for medical irradiation and fundamental examination of it.
Kato, Tomoaki; Araki, Masaaki; Izumo, Hironobu; Kinase, Masami; Torii, Yoshiya; Murayama, Yoji
JAEA-Technology 2007-050, 39 Pages, 2007/08
On the conversion from aluminide fuel to silicide fuel, burnable absorbers were introduced for decreasing excess reactivity. The burnable absorbers influence reactivity during reactor operation. So, the burning of the burnable absorbers was studied and the influence on reactor operation was made cleared. Furthermore, necessary excess reactivity on beginning of operation cycle and the time limit for restart after unplanned reactor shutdown was calculated. After the conversion, the fuel exchange procedure was changed from the six-batch dispersion procedure to the fuel burn-up management procedure. The previous estimation of fuel burn-up was required for the planning of fuel exchange, so that the estimation was carried out by means of past operation data. Finally, a new fuel exchange procedure was proposed for effective use of fuel elements. The average length of fuel-staying in the core can be increased by two percent on the procedure.
Izumo, Hironobu; Kato, Tomoaki; Kinase, Masami; Torii, Yoshiya; Murayama, Yoji
JAEA-Technology 2007-046, 23 Pages, 2007/07
JRR-3 (Japan Research Reactor No.3) has been operated for about 15 years after the modification, without significant troubles by carrying out maintenance such as the preventive maintenance (mainly Time-Based Maintenance: TBM) for the safety-grade equipments and the breakdown maintenance for the non-safety-grade equipments. Recently, numbers of unscheduled shutdowns caused by aging of the non-safety-grade equipment have been increasing, but resources for both maintenances have been decreasing year by year. In such a situation, new JRR-3 maintenance program is studying and reviewed considering safety, reliability and economical. In the evaluation, the maintenance data (i.e. vibration, measurement, etc.) which accumulated on JRR-3 is applied effectively. This report offers the policy on the maintenance review at JRR-3 and the future direction of JRR-3 maintenance programs.
Yamamoto, Tetsuya*; Matsumura, Akira*; Nakai, Kei*; Shibata, Yasushi*; Endo, Kiyoshi*; Sakurai, Fumio; Kishi, Toshiaki; Kumada, Hiroaki; Yamamoto, Kazuyoshi; Torii, Yoshiya
Applied Radiation and Isotopes, 61(5), p.1089 - 1093, 2004/11
no abstracts in English
Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Torii, Yoshiya; Sakurai, Yoshinori*; Kobayashi, Toru*
Proceedings of 11th World Congress on Neutron Capture Therapy (ISNCT-11) (CD-ROM), 15 Pages, 2004/10
To carry out the boron neutron capture therapy (BNCT) using the epithermal neutron, the epithermal neutron beam intensity was measured by using Au reaction rate activated on the resonance absorption peak (4.9eV). Two scaling factors, which are the reactor power calibration factor and the calculation/experiment (C/E) scaling factor, are necessary in order to correct with the simulation and actual irradiation experiment. First, an optimum detector position was investigated using MCNP code. The result of MCNP calculation showed that the influence of subject placed at the collimator was below 1% when the detector was placed in the distance of over 20cm from the collimator. Therefore we installed the monitor holders near the bismuth block in order to set three gold wire monitors. The factors were determined in the calibration experiments that measure the thermal neutron flux in the phantom and reaction rate of the gold wire monitors. The monitoring technique to measure epithermal neutron beam intensity was applied to clinical irradiation with the epithermal neutron beam.
Kumada, Hiroaki; Yamamoto, Kazuyoshi; Torii, Yoshiya; Matsumura, Akira*; Nakagawa, Yoshinobu*
Japanese Journal of Medical Physics, Vol.23, Supplement 3, p.292 - 295, 2003/09
no abstracts in English
Yamamoto, Tetsuya*; Matsumura, Akira*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Hori, Naohiko; Torii, Yoshiya; Shibata, Yasushi*; Nose, Tadao*
Radiation Research, 160(1), p.70 - 76, 2003/07
The survival curves and the RBE for the dose components generated in boron neutron capture therapy (BNCT) were determined separately in neutron beams at JRR-4. The surviving fractions of V79 cells with or without 10B were obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal (TNB-2) neutron beam. The cell killing effect of the neutron beam in the presence or absence of 10B was highly dependent on the neutron beam used and depended on the epithermal and fast-neutron content of the beam. The RBEs of the boron capture reaction were 4.07, 2.98 and 1.42, and the RBEs of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50, 2.34 and 2.17 for ENB, TNB-1 and TNB-2, respectively. The approach to the experimental determination of RBEs allows the RBE-weighted dose calculation for each dose component of the neutron beams and contributes to an accurate inter-beam comparison of the neutron beams at the different facilities employed in ongoing and planned BNCT clinical trials.
Kumada, Hiroaki; Yamamoto, Kazuyoshi; Torii, Yoshiya; Matsumura, Akira*; Yamamoto, Tetsuya*; Nose, Tadao*; Nakagawa, Yoshinobu*; Kageji, Teruyoshi*; Uchiyama, Junzo
JAERI-Tech 2003-002, 49 Pages, 2003/03
no abstracts in English
Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Torii, Yoshiya; Endo, Kiyoshi*; Yamamoto, Tetsuya*; Matsumura, Akira*; Uchiyama, Junzo; Nose, Tadao*
JAERI-Tech 2002-092, 23 Pages, 2002/12
Thermal neutron flux is determined using the gold wires in current BNCT irradiation, so evaluation of arbitrary points after the irradiation is limited in the quantity of these detectors. In order to make up for the weakness, dose estimation of a patient is simulated by a computational dose calculation supporting system. In another way without computer simulation, a medical irradiation condition can be replicate experimentally using of realistic phantom which was produced from CT images by rapid prototyping technique. This phantom was irradiated at a same JRR-4 neutron beam as clinical irradiation condition of the patient and the thermal neutron distribution on the brain surface was measured in detail. This experimental evaluation technique using a realistic phantom is applicable to in vitro cell irradiation experiments for radiation biological effects as well as in-phantom experiments for dosimetry under the nearly medical irradiation condition of patient.
Kumada, Hiroaki; Torii, Yoshiya
JAERI-Data/Code 2002-018, 158 Pages, 2002/09
A boron neutron capture therapy (BNCT) with epithermal neutron beam is expected to treat effectively for malignant tumor that is located deeply in the brain. It is indispensable to estimate preliminarily the irradiation dose in the brain of a patient in order to perform the epithermal neutron beam BNCT. Thus, the JAERI Computational Dosimetry System (JCDS), which can calculate the dose distributions in the brain, has been developed. JCDS is a software that creates a 3-dimentional head model of a patient by using CT and MRI images and that generates a input data file automaticly for calculation neutron flux and gamma-ray dose distribution in the brain by the Monte Carlo code: MCNP, and that displays the dose distribution on the head model for dosimetry by using the MCNP calculation results. JCDS has any advantages as follows; By treating CT data and MRI data which are medical images, a detail three-dimensional model of patinet's head is able to be made easily. The three-dimensional head image is editable to simulate the state of a head after its surgical processes such as skin flap opening and bone removal for the BNCT with craniotomy that are being performed in Japan. JCDS can provide information for the Patient Setting System to set the patient in an actual irradiation position swiftly and accurately. This report describes basic design and procedure of dosimetry, operation manual, data and library structure for JCDS (ver.1.0)
Yamamoto, Kazuyoshi; Kumada, Hiroaki; Torii, Yoshiya; Kishi, Toshiaki; Yamamoto, Tetsuya*; Matsumura, Akira*
Research and Development in Neutron Capture Therapy, p.499 - 503, 2002/09
In order to estimate the maximum gamma-ray dose in the brain in Intra-Operative Boron Neutron Capture Therapy (IOBNCT), this study was conducted for (1) the development of low neutron-sensitive TLD (UD-170LS-T2), (2) the correlation of capture gamma-ray dose profile in a phantom for various collimator sizes, and (3) the formula for simple estimation of maximum gamma-ray dose on IOBNCT. The sensitivity of TLD, as Co -ray equivalent, for thermal neutron was 5.10.810(Co-Gycm)The average relative deviations between predicted and measured -ray dose for the mixed epithermal-thermal neutron beam in the phantom were 8.5%. The accuracy of the -ray dose determination in the clinical BNCT may be improved by this simple method.
Kumada, Hiroaki; Matsumura, Akira*; Nakagawa, Yoshinobu*; Yamamoto, Tetsuya*; Yamamoto, Kazuyoshi; Torii, Yoshiya
Research and Development in Neutron Capture Therapy, p.529 - 534, 2002/09
no abstracts in English
Kumada, Hiroaki; Kishi, Toshiaki; Hori, Naohiko; Yamamoto, Kazuyoshi; Torii, Yoshiya
Research and Development in Neutron Capture Therapy, p.115 - 119, 2002/09
no abstracts in English
Matsumura, Akira*; Yamamoto, Tetsuya*; Shibata, Yasushi*; Nakai, Kei*; Zhang, T.*; Matsushita, Akira*; Takano, Shingo*; Endo, Kiyoshi*; Akutsu, Hiroyoshi*; Yamamoto, Kazuyoshi; et al.
Research and Development in Neutron Capture Therapy, p.1073 - 1078, 2002/09
Since 1998 to 2002, a new clinical trial of an intraoperative boron neutron capture therapy (IOBNCT) at JRR-4 of Japan Atomic Energy Institute (JAERI) using BSH with mixed thermal/epithermal neutron beam has been accomplished. There have been 9 patients included in this study. The median survival time (MST) in GBM was 19.8 months and 16.8 months in AA. IOBNCT with mixed thermal/epithermal neutron beam provide better primary radiation effect than conventional therapy in selected cases. Our phase I/II clinical trial was effective in local tumor control. Further clinical trial with new design should be performed to prove the efficacy of IOBNCT.
Endo, Kiyoshi*; Matsumura, Akira*; Yamamoto, Tetsuya*; Nose, Tadao*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Torii, Yoshiya; Kashimura, Takanori*; Otake, Shinichi*
Research and Development in Neutron Capture Therapy, p.425 - 430, 2002/09
Using the Rapid Prototyping Technique, we produced a realistic phantom as a formative model of a patient head. This realistic phantom will contribute to verification of our planning system. However, cross-correlation among the calculations using the JAERI Computational Dosimetry System (JCDS), the realistic phantom, and the in vivo measurements were not fully completed because of the difficulty involved in modeling a post-surgical brain and a thermal neutron shield. The experimental simulation technique using the realistic phantom is a useful tool for more reliable dose planning for the intraoperative BNCT.
Yamamoto, Tetsuya*; Matsumura, Akira*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Torii, Yoshiya; Endo, Kiyoshi*; Matsushita, Akira*; Shibata, Yasushi*; Nose, Tadao*
Research and Development in Neutron Capture Therapy, p.415 - 418, 2002/09
Dose measurements in a patient's brain undergoing intraoperative BNCT (IOBNCT) were compared with calculations by a JAERI computational dosimetry system (JCDS). The maximum thermal neutron flux on the brain surface from the postirradiation measurement averaged 2.330.37(10cms) and the vascular boron dose averaged 11.41.2 (9.6-12.7) Gy. Using JCDS, the maximum thermal neutron flux in the irradiated volume averaged 2.210.33(10cms), while the target vascular dose averaged 5.7 Gy and varied from 3.5 to 7.8 Gy. As such, in the dose planning for intra-operative irradiation, practical use of JCDS is recommended for uniform volume-dose control of postsurgical brain in IOBNCT.
Yamamoto, Tetsuya*; Matsumura, Akira*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Hori, Naohiko; Torii, Yoshiya; Endo, Kiyoshi*; Matsushita, Akira*; Yoshida, Fumiyo*; Shibata, Yasushi*; et al.
Research and Development in Neutron Capture Therapy, p.697 - 700, 2002/09
The RBE of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at JRR-4. The cell killing effect of the neutron beam with or without the presence of 10B was highly dependent on the neutron beam used, according to the epithermal and fast neutron content in the beam. RBE (BARBEboron) values of the boron capture reaction for an epithermal (ENB), a mixed thermal-epithermal (TNB-1), and a thermal (TNB-2) neutron beams were 3.990.24, 3.040.19 and 1.430.08, respectively.
Nakai, Kei*; Matsumura, Akira*; Yamamoto, Tetsuya*; Shibata, Yasushi*; Zhang, T.*; Akutsu, Hiroyoshi*; Matsuda, M.*; Matsushita, Akira*; Yasuda, Susumu*; Takano, Shingo*; et al.
Research and Development in Neutron Capture Therapy, p.1135 - 1138, 2002/09
7 patients have been undergoing Intraoperative boron neutron capture therapy (IOBNCT) for malignant glioma at Japan Atomic Energy Institute (JAERI). Post-BNCT MRI studies revealed one local recurrence and two distant recurrences. Distant recurrence is uncommon in the conventional radiation therapy. Symptomatic late radiation necrosis occurred in one case.
Matsushita, Akira*; Yamamoto, Tetsuya*; Matsumura, Akira*; Nose, Tadao*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Torii, Yoshiya; Kashimura, Takanori*; Otake, Shinichi*
Research and Development in Neutron Capture Therapy, p.141 - 143, 2002/09
A thermal-epithermal mixed beam "Thermal Neutron Beam Mode I" was used in the eleven sessions of boron neutron capture therapy which have been performed at JRR-4 from 1998. We are planning to use an epithermal beam for the treatment of deeper tumors in the next trial of the intraoperative BNCT. In this study, "Epi-12" which was made by putting up a cadmium shutter of "Thermal Neutron Beam Mode I" was investigated for the clinical benefits and safety by epithermal beams. Decrease of fast neutron contamination ratio in Epi-12 mode is the advantage for BNCT, particular in the intraoperative BNCT. Because fast neutron on the brain surface is one of the critical factors in the intraoperative BNCT in which the plain beam directly interacts the normal structures. Furthermore a mixture of mode Epi-12 and Th-12 will provide various dose distribution designs. It may be used as a new method to control the best distribution for individual tumors.