Abstract We developed a hammering sound inspecting system using AE sensor with objectivity and recordability and confirmed that it is possible to grasp the state of concrete (internal cavity and surface peeling) from the vibration analysis result obtained , And confirmed the usefulness of concrete health diagnosis using this system. ...
英字タイトル:
Development of nondestructive inspection system for soundness diagnosis of concrete structure

In order to grasp efficiency of risk information, we tried to apply an insight of PRA to considering of severe accidents; TMI, Chernobyl, and Fukushima Dai-ichi. Based on this analysis, three points are disclosed. At first, PRA can product adequate countermeasures for low-likelihood events; huge earthquake or Tsunami. Next, PRA can prove weak points in design or operation reasonably. Third point is safety culture. PRA and safety culture are seemed to be connected deeply. These analyses revealed PRA is on...
英字タイトル:
-For Discussions with the Public for the Safety of Nuclear Power -Applying Risk Information to Prevention/Mitigation of SA-

Target of PRA is not calculating PRA to get CDF/CFF, but providing significant and useful information from PRA results for risk-informed activities. Lot of risk applications have been implemented these about 20 years in US. After Fukushima Dai-ichi accidents, Japanese Nuclear Regulation Authority provided new regulatory requirements about external events and beyond design events. And Risk Application faces full-scale implementation. In this report, several methods of risk application are showed with adeq...
英字タイトル:
- For Discussions with the Public for the Safety of Nuclear Power -Various Patterns of Risk Application Method and Examples-

After Fukushima daiichi nuclear accident, it becomes more important risk communication with the public. In discussions with the public in nuclear safety, communication and discussions on risks that not only nuclear risks also social risks are important. Differences in viewpoints, understanding, and thought about risks become communication difficult. We need to discuss risks fairly, appropriately with the public and reduce total social risks. ...
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For Discussions with the Public for the Safety of Nuclear Power -Discussion with the Public -

In considering nuclear safety, it is an important task to clarify the relationship with peace of mind that is the heart of people. What is the state that scientific safety is something that people feel safe. We considered the relationship between quantified risk and safety, and ways to acquire peace of mind. We analyzed the thresholds of safety risks as a social common sense, showed a safe condition, and showed the importance of forming a consensus to obtain peace of mind. ...
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For Discussions with the Public for the Safety of Nuclear Power -Safety and Secure-

1.はじめに 社会においては、リスクの理解は様々である。リスク をどのように理解していけば良いのかを示し、リスクについての社会との向き合い方をまとめる。個人のリスク の受け入れは個人で行うものであるが、 社会のリスクは、社会としていかなるリスクを許容するかという仕組みを社会で構築する必要がある。そのためにも、社会リスクとはどんなものであり、どのように社会また個人は、それにどう向き合い、受け入れるリスクの選択をどう行うべきかを述べる。また、原子力リスクの考え方とそれを 一般公衆に対する防災の観点からどのよう......
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For Discussions with the Public for the Safety of Nuclear Power -Social risk and Nuclear risk -

1.はじめに リスクとは、判断を支援する指標である。したがって、 何を判断しようとするかによって、何がリスクかは異な ってくる。原子力システムの安全に関するリスクといっ ても、安全に対するどのような影響を判断しようとして いるかによって、検討すべきリスクは異なってくる。 また、リスクとは、影響を与えるものと与えられるも のの相互作用である。そのために、原子力システムに関 するリスクを検討する際には、影響を与える原子力シス テムに関する知見と、影響を受ける社会に関する知見が 必要となってくる。さらには、原子......
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For Discussions with the Public for the Safety of Nuclear Power -Risks for judgments-

Special attentions have been increasingly paid for the diagnosis of social infrastructures after the collapse of ceiling of Sasago tunnel of Chuo Expressway. It is reported that the main cause was due to the age-related degradation of chemical anchors. Chemical anchors are also frequently used in nuclear power stations. Here we have been trying to apply PFM (Probabilistic Fracture Mechanics) to the diagnosis of social infrastructures using Dr. Mainte, an integrated simulator to optimize maintenance activi...
英字タイトル:
A Study of Application of PFM (Probabilistic Fracture Mechanics) to the Diagnosis of Social Infrastructures ]

Development of methods of detecting degradation of irradiated reactor structural materials is required for successful operation of nuclear power plants. Ultrasonic waves, currently used as a non-destructive technique to detect cracks, change as a result of interacting with microstructural components and can be employed to measure radiation-induced changes in microstructure. Bulk-averaged measurements of microstructural changes can be determined usi ng ultrasonic velocity, attenuation and back-wall echo, wh...
英字タイトル:
Development of non-destructive inspection technique for microstructuresunder irradiation using decommissioned materials(1) An experimental approach

Abstract It is desired to develop an ultrasonic inspection technique non-destructively measuring various forms of irradiation-induced degradation in structural components of nuclear reactors. In order to evaluate the depth distributions of ir radiation-induced microstructural changes, we have developed a numerical simulation model of ultrasonic wave changes caused by microstructural changes in austenitic stainless steel based on the developed theory of ultrasonic wave propagation for comparison with experi...
英字タイトル:
Development of non-destructive inspection technique for microstructures under irradiation using decommissioned materials(2) An theoretical approach