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Sanada, Yukihisa; Miyamoto, Kenji*; Momma, Hiroyasu*; Miyazaki, Nobuyuki*; Nakasone, Takamasa*; Tahara, Junichiro*; Baba, Shoichiro*; Furuyama, Hiroki*
Marine Technology Society Journal, 55(5), p.222 - 230, 2021/09
Large quantities of volatile radionuclides were released into the atmosphere following the Fukushima Daiichi Nuclear Power Station (FDNPS) accident in March 2011. To evaluate their effect on aquatic organisms and radiocesium behavior in the environment, the monitoring of radioactive cesium in the waterbed soil is important. We developed a dedicated radiation survey device that can both directly measure and collect some sediment samples. A comprehensive test was conducted using this device, which was installed in an unmanned surface vehicle at Fukushima offshore contaminated by radiocesium that resulted from the FDNPS accident. Consequently, the effectiveness of this device was confirmed because the measurement results of the sediment-core sample and in-situ radiation survey results show a good correlation. A successful application of this device in the time of post-nuclear facility accident is expected.
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JNC TN1400 2001-013, 70 Pages, 2001/08
JNC-TN1400-2001-013.pdf:5.13MB
no abstracts in English
PNC TN9410 97-011, 45 Pages, 1997/01
In the study for the development of the sub-criticality monitoring system for the nuclear fuel facilities, wavelet analysis was applied to detect the neutron multiplication system is approaching to critical. Neutron noise signal is the measured data for the monitoring, and the data was accumulated in the multi-channel scaler of the neutron detection system. From the point of view of the simplicity of numerical calculations of the MCS data, discrete wavelet transform by using the Cardinal spline functions was selected in the varaiety of wavelet funtions. Simulated noise data of the system without neutron multiplication was numerically produced and also transformed by the wavelet analysis procedure to be compared to the results from the nutron multiplication system. The approach to the critical can be detected by checking the difference of the two kinds of transformed results, with and without neutron multiplications. The method was applied to the neutron noise signal obtained at the Deuterium Critical Assembly(DCA), and it was confirmed that approaching to critical can be detected by tbe present method.
; ; Ozawa, Kenji; *; *
PNC TN9410 97-006, 46 Pages, 1996/12
Since it is desired to enhance availability and safety of nuclear power plants operation and maintenance by removing human factor, there are many researches and developments for intelligent operation or diagnosis using artificial intelligence(AI) technique in the Frontier Research. In this development, We have been developing an autonomous operation and maintenance system for nuclear power plants by substituting AI's. On the other hand, Ship Research Institute(SRI) have been developing a monitoring system for cooperative function of distributed systems in the autonomous operation and maintenance systems. In this report, we have studied telecommunication methods between PNC and SRl to combine the autonomous operation and maintenance system and its monitorillg systan. As the result, we have confinned a proper performance of that telecommunication facility by the test via public telephone line or Internet.
Tsutani, Sadahiro*; Takeshita, Hiroshi*; Edajima, Toshikazu*; Motooka, Masafumi*
PNC TJ8224 93-001, 128 Pages, 1993/06
no abstracts in English
Mukaiyama, Takehiko; Ogawa, Hironobu
Dai-14-Kai Kaku Busshitsu Kanri Gakkai Nenji Taikai Rombunshu, p.138 - 145, 1993/00
no abstracts in English
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PNC TN1410 91-097, 17 Pages, 1991/12
This report describes the results of project JD-12 including JD-9. The objective of this project is to develop a remote surveillance system with a trigger devices which consist of 
ray monitor and electronic sealing switch. The concept of the system is going to be applied to an automatich storage of new MOX plant which is fully automated.
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PNC TN941 81-52, 296 Pages, 1981/02
Recently surveillance systems for nuclear power plants are increasingly required for the improvement of plant safety and availability. In order to establish the surveillance system of the prototype fast breeder reactor "MONJU", some techniques have been developed and applied to the 50MW Steam Generator Test Facility ty at OEC. As the first stage of the development, information display techniques for the plant operators and some anomalous state detection techniques are discussed in this paper. The operators can obtain such plant informations as digital and graphic outputs by cathode ray tubes (CRTs) and print out by a lineprinter and typewriters. Also the operators are informed of results of anomalous diagnosis by annunciator alarms moment by moment. Application tests of the anomalous state detection techniques have been carried out. These techniques include a cross check technique of multi-measuring system, a automatic detection system of a small scale sodium-water reaction, a differential alarm and prediction method of the time of anomalous occurrance and a display method of degree of superheat of evaporator (EV) outlet steam. It was concluded by our evaluation of the test results that those techniques are applicable to the "MONJU" design without major modification. We will develop new techniques and improve these systems to make them applicable to "MONJU", considering the "man-machine system", using this test facility.
