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Until around 1990 Japanese nuclear power generation maintained the world’s top-level safety and high capacity factors. However, repeated accidents and troubles in the latest decade (including those experienced earlier and newly uncovered) caused the capacity factors decline, and simply the regulatory authorities reinforce their rules. Nevertheless, Japan has maintained its nuclear technologies and knowledge by continued constructions of new nuclear power plants (NPP) and the technology and knowledge were handed down and accumulated., while the construction decreased drastically worldwide after the Chernobyl accident in 1986. It should be meaningful to see how Nuclear Knowledge Management (NKM) worked over this period. All 17 nuclear power stations in Japan were visited from January to September 2007 for field survey of maintenance practices, human resources development programs and quality assurance activities. From the analyses of the collected information, the strengths and weaknesses in nuclear knowledge management have been induced. The lessons we concluded are elaborated in the following subjects. • Pluses (+) and minuses (-) of multi-layered structures of nuclear industry: its correlation with NKM (accumulation, preservation and creation of technologies and knowledge); • Technology improvement and knowledge accumulation in the new quality assurance systems; • “Olds” and “News” in transferring technologies and knowledge, and in developing human resources; • Rebuilding of on the job training (OJT) and off the job training (Off - JT): its contents of lessons and training; • Appropriate use of the manuals: to know its usefulness and limits; • Appropriate deployment of the inspection enforcement: incentives and formalities; • Motivation of active information sharing by the adequate intellectual property management; • Lateral development of best practices, and new value creation by the shared knowledge. The Japanese electric utilities and nuclear industry should further advance their information sharing of valuable experiences such as troubles and good practices, and strengthen their self-management. Thus, they will be able to contribute, with their advanced strengths of accumulated/preserved nuclear technologies and knowledge, to meeting the growing needs of new NPP construction worldwide in the Nuclear Renaissance. NKM will in turn be further advanced on the so-called spiral-up track.

Sandia National Laboratories (SNL) has conducted an extensive study of emergency response planning applicable to sea transport of plutonium for the Japan Nuclear Cycle Development Institute (JNC). This work covered four separate areas to better define the accident environment for long range sea transport of nuclear materials. A probabilistic safety analysis evaluated technical issues for the transport of plutonium between Europe and Japan. An engine room fire aboard a purpose built ship was used to analyse the vulnerability of plutonium packaging designed to International Atomic Energy Agency (IAEA) standards. A comprehensive corrosion study estimated the time required for sea water to breach a containment boundary in submerged generic plutonium packaging. A survey of worldwide commercial recovery capabilities provided a compilation of information on the capabilities of salvaging high value cargo from sunken ships. This paper addresses salvage modes from harbour depths to the deepest ocean trenches. Previous studies (J. L. Sprung et al., SNL reports SAND98-1171/1 and SAND98-1171/2, May 1998) included a probabilistic risk assessment of the overall safety, source term evaluations and finite element structural dynamics calculations to determine the effects of ship to ship collisions on nuclear material containers and the effects of ship fires on transport packaging as determined by actual fire experiments conducted on board a test ship. The previous studies, together with this work, form a comprehensive technical basis that encompasses the overall safety of sea transport of plutonium between Europe and Japan. Based on these technical analyses, transport of nuclear materials by sea in Type B packaging, approved in accordance with US Nuclear Regulatory Commission (NRC) and IAEA regulations, and carried in purpose built ships with adequate surveillance, has a very high degree of safety for the failure modes studied. Non-purpose built ships do not have the redundancy in safety features provided by the newer purpose built ships. However, SNL studies on non-purpose built ships have shown accident environments to be within NRC and IAEA regulatory assumptions for Type B packaging. These studies were carried out for both structural ship to ship collisions and engine room fires by analysis (for the collisions) and direct experimentation and analysis (for the fires). Thus, land transport mode regulations are applicable for sea transport accident conditions.

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The use of best practices and their lateral expansion as a benchmark is one of effective methods of “knowledge management (NK)”. Best practices of human resources development were collected (selected examples are listed below) from all 11 training centers annexed to the nuclear power plants in Japan and lessons were learned for possible lateral development for improving other stakeholders’ NK. Such best practices will provide productive information for designing their own human resources development strategies. Examples of collected good practices: • Exhibition of troubles and negative legacies: The actual machineries, equipment or components, explanatory documents or news articles of the past troubles experienced by themselves are effective to maintain and refresh the awareness and preparedness of trainees and other employees for recurrence prevention. The exhibitions are open to the visitors, too. • Experience-type training facilities: Off-normal conditions of components and systems are simulated for the staff practical training by the use of the facilities which provide an off-normal environment. Examples are: water hammers, abnormal vibrations and noises of rotating machineries, pump cavitations, pinholes, plumbing airs, etc. • Advanced simulators for operators training: Each electric company has its own simulators for training their own operating staff. These simulators are annexed to the nuclear power plants and used to train the operation staff by the experienced shift managers. The operation staff use the simulator for continually confirming the operation procedures and the plant behavior, etc. specific to their plants. Training for generic plant behavior and operators’ responses are mainly outsourced to the dedicated training centers run by the Owners’ Groups (BWR, PWR). • The SAT methods: The IAEA proposed SAT (Systematic Approach to Training) approach is applied to the training of the operating staff and the maintenance staff. It is structured in a flow of Job analysis ← Training program design ← Training material development ← Training ← Evaluation. • Training in real situations: An example is a trainee actually hung with a lifeline on a harness to learn a method of putting on the lifeline. On the other hand, the efficiency (availability) of the training facilities for maintenance work is very limited, because each electric company installs the training facilities individually. Experiences of ICONE-16 participants from other countries in improving the availability are of our interest.