[en] Requirements put on the preliminary and pre-operation safety reports on radioactive waste depositories, as following from Czechoslovak regulations No. 85/1976 and 67/1987, are commented on. Basic approaches to the compilation of the required documentation are described, and practical experience gained during its writing is discussed. (author). 18 refs

[en] In British Nuclear Fuels plc (BNFL), the design of nuclear chemical plants for construction and subsequent operation at Sellafield Works is carried out by the Engineering Division of the Spent Fuel Management Services Group based at Risley, Warrington. Plant construction cannot take place, nor plant commissioning, until it has been demonstrated in the initial (design) safety case that the chosen design will allow the plant to be operated in an adequately safe manner, corresponding to an extremely low level of risk. The safety documentation procedure is described. A Preliminary Design Safety Appraisal is made of the initial design proposal to give an early indication of the order of risk that might prevail. The risk from each hazard is compared with an allocated risk target which makes up a proportion of the total plant risk which is quantified in BNFL's risk criteria. Where the risk appears unacceptable, appropriate modifications are made to the design. Prior to commissioning, a comprehensive, detailed risk assessment is carried out. The methodology of probabilistic risk assessment is described and examples given of how different hazards are assessed. (author)

[en] This appendix provides recommendations on aspects of management systems that are specific to the phases of operation, closure and post-closure active institutional control for disposal facilities for radioactive waste, to supplement the recommendations in the body text of the related safety Guide. It covers issues like establishing procedures, management of waste packages, maintenance of the facility during operation, surveillance of the facility, facility records, periodic safety review, emergency preparedness and response, housekeeping and cleanliness, purchasing, effluent monitoring and signposting

[en] A study has been made with the focus on different theories and applications concerning 'safety functions' and 'barriers'. In this report, a safety function is defined as a technical or organisational function with the aim to reduce probability and/or consequences associated with a hazard. The study contains a limited review of practice and theories related to safety, with a focus on applications from nuclear and industrial safety. The study is based on a literature review and interviews. A summary has been made of definitions and terminology, which shows a large variation. E.g. 'barrier' can have a precise physical and technical meaning, or it can include human, technical and organisational elements. Only a few theoretical models describing safety functions have been found. One section of the report summarises problems related to safety issues and procedures. They concern errors in procedure design and user compliance. A proposal for describing and structuring safety functions has been made. Dimensions in a description could be degree of abstraction, systems level, the different parts of the function, etc. A model for safety functions has been proposed, which includes the division of a safety function in a number connected 'safety function elements'. One conclusion is that there is a potential for improving theories and tools for safety work and procedures. Safety function could be a useful concept in such a development, and advantages and disadvantages with this is discussed. If further work should be done, it is recommended that this is made as a combination of theoretical analysis and case studies

[en] Industry has noted that Competent Authorities of different countries do not have the same approach about how the transport and/or handling frames, where they exist, should be taken into account in the safety analysis. This subject is critical when having to comply with the requirements of paragraph 611 in the 2005 Edition of the IAEA Transport Regulations for the Safe Transport of Radioactive Material (TS-R-1): 'Any features added to the package at the time of transport which are not part of the package shall not reduce its safety'. This topic was considered in IAEA during the fifteenth meeting of the Transport Safety Standards Committee (TRANSSC 15) in October 2007 and subsequent meetings under the aegis of IAEA. It was further discussed in industry fora such as the World Nuclear Transport Institute (WNTI), in order to refine their common position. This paper will consider the following questions, with an industry perspective. - What are the technical and administrative difficulties when dealing with the requirements of paragraph 611 in TS-R-1? - What are the boundaries of the package? What is a feature added to the package at the time of transport? - How to assure safety of transports when considering the added features? - What is the current position of the various parties after their meetings? - How to go further? (authors)

[en] KAERI is being developed pyroprocessing technology for spent fuel recycling. For this it is necessary to establish the facility development technology. In this paper the Hybrid ISA-PSA method developed by US NRC was introduced and studied the adaptability on safety of pyroprocess facilities. In this paper, the Hybrid ISA-PSA method, suggested by US NRC, for safety evaluation of SF recycling facilities was introduced and studied the adaptability to pyroprocess facilities. According to this study, it is concluded that sole ISA, not Hybrid ISA-PSA, can be a good method to evaluate safety of pyroprocess facilities

[en] In this report, we investigated the general processes to model the groundwater flow system in a fractured aquifer and the mathematical approaches to simulate it. Then, we reviewed several modeling cases of nuclear advanced nations (e.g. Switzerland, U.S., Canada, and Sweden) for simulating the groundwater flow system for safety assessment of their real or hypothetical radwaste repository. From the reviews, we introduced some requisite research items

[en] Pyroprocess technology has been considered as a fuel cycle option to solve the spent fuel accumulation problems in Korea. The Korea Atomic Energy Research Institute has been studying pyroprocess technology, and the conceptual design of an engineering-scale pyroprocess facility, called the Advanced Fuel Cycle (AFC) facility, has been performed on the basis of a 10tHM throughput per year. In this paper, the concept of the AFC facility was introduced, and its safety evaluations were performed. For the safety evaluations, anticipated accident events were selected, and environmental safety analyses were conducted for the safety of the public and workers. In addition, basic radiation shielding safety analyses and criticality safety analyses were conducted. These preliminary safety studies will be used to specify the concept of safety systems for pyroprocess facilities, and to establish safety design policies and advance more definite safety designs

[en] Oskarshamn is one of two Swedish municipalities where site investigations are conducted by SKB as possible sites for a final repository for spent nuclear fuel. The municipality has been an active part in the process since 1994 when Oskarshamn was pointed out as a suitable site for an encapsulation plant. A project organisation LKO Local Competence Building was set up 1994 and it is financed by the Swedish nuclear fund. There are two leading themes that form the basis for our participation complete openness of plans and results and participation with the possibility to influence. Site investigations for a repository started 2002 and will be finished when SKB has selected a site, which is planned late 2009. To follow up the site investigations an organisation based on working groups has been set up. The groups are the Safety Group, The Misterhult Group and the Future Perspective Group. About 45 persons are participating in the groups. The members are politicians, civil servants, people representing various associations and interested citizens. The main goal for the LKO organisation is to present a comprehensive report to the municipality council if SKB will apply for a final repository in Oskarshamn. When the municipality council accepted site investigations the decision was taken with 13 conditions. The most important conditions are about long term safety. (author)

[en] To secure the safety of the radioactive waste repository, derivable scenarios are developed as many as possible and further safety assessment must be performed. For this, an external review of KAERI FEP List and Scenario is carried out. The scope and contents of the project are Previous FEP and scenario review, Further development of RES(Rock Engineering System) and Scenario development using PID(Process Influence Diagram). As a result, FEP list is complemented and more scenarios are developed using RES methodology. Using the methodology developed, various scenario for safety assessment can be derived and applied in future disposal business