Licensing Data Base: a tool to aid safety upgrading29 October 1998
To assist in designing, supplying and licensing plant and systems used in nuclear applications, Stork Nucon developed the Licensing Data Base (LDB) which contains vital national and international nuclear codes and standards documents. Safety upgrading, renovating and maintenance are only a few of activities that can benefit from using this tool.
Over the past several years Stork Nucon has developed the Licensing Data Base (LDB) which lists and correlates a large number of nuclear regulatory requirements, codes, standards and other published documents that play a role in the design, licensing, operation and upgrading of nuclear power plants. The documents are correlated by assigning to each a number of attributes in terms of subject, activity and system.
The LDB has been developed in an engineering environment and applied by Stork Nucon in developing designs, including backfitting projects based on licensing updates of nuclear power plants.
Documents contained in the data base cover the categories of legal requirements, regulations, regulatory/safety guides and industrial codes and standards. All documents are identified by reference to the issuing organisation, and give full details of publication number, title and date of issue. Table 1 presents an overview of the most important organisations issuing nuclear codes and standards which are contained in the data base.
The USNRC Regulatory Guide 1.701 provides the main framework for making systematic correlations. An additional correlation scheme is derived from the table of contents of the report EUR 7135,2 a compilation of nuclear standards. The subjects are assigned by means of the numbers of chapters, sections and (in the case of RG 1.70) sub-sections.
Other correlation schemes include the type of activity for which the document is generally used, such as design, procurement, operation, inspection and maintenance, and system numbers or component numbers, generally only used for a set of documents that is applicable to a specific plant design.
Finally, a correlation can be made to miscellaneous subjects that address particular subjects that do not appear in the title of the document or in the titles of the subjects of RG 1.70 and EUR 7135. The organisation of the data base consisting of data for standards and correlations is schematically shown in the figure. For a quick familiarisation of the content of a document, an abstract of the document has been added to the data base.
Using the Licensing data Base
The LDB is a tool which can be consulted and used to make selections of codes and standards applicable to perform safety upgrading.
The data base can be used for design basis reconstruction and for checking the conformity of the Safety Analysis Report, as part of the plant licence, and for design specifications and maintenance documents.
It is also a help in updating specifications by allowing a comparison with state-of-the-art standards for a subject. In particular, activities related to configuration management, such as specifying requirements for new components, involve the consideration of recently issued standards. Configuration management is aimed to assure that all technical documentation is kept up-to-date with the actual plant status (the configuration).
The LDB can have a function in determining which safety standards, methods and practices are used as a basis for the periodic safety review of operating nuclear power stations.
When it comes to backfitting programmes for nuclear plants the parts of a plant that are modified will have a status of design in which the latest codes and standards have been applied.
The date of issue of a code or standard is consistently carried in the data base, so that distinction can be made between original and later issues or additions to codes and standards. Superseded and obsolete issues of standards are retained in the data base with reference to their status. The computer application enables the selection of codes and standards issued during a specified period of time for the purpose of reconstructing an original design basis and that of later modifications.
The LDB can also assist in the national implementation of international requirements.
EXAMPLES IN USING LICENSING DATA BASE
A few examples of codes and standards that are part of the data base can be given. There are the USA’s 10CFR50 General Design Criteria that have been correlated individually to the RG 1.70 sub-sections. All Regulatory Guides have been given. The content of the Standard Review Plan (NUREG 8003) runs parallel to that of RG 1.70, therefore codes and standards correlated to RG 1.70 have an immediate correspondence with the SRP. Of the American industrial standards the nuclear ‘c’ parts of ASME, ASTM, ANSI/ANS and IEEE have been incorporated. The IAEA Codes of Practice and Safety Guides of the 50-series for governmental organisation, siting, design, operation and quality assurance are given, along with many topical reports and proceedings.
Nowadays the IAEA codes and guides are being applied in several countries, sometimes in an amended form adapted to national circumstances. The German KTA (nuclear technology) standards and the nuclear related DIN standards are also available in the data base. Not only officially issued regulations, but also topical reports, recommendations and state-of-the-art reviews are present such as NUREG and IAEA reports.
Managing the Licensing data base
With the Licensing Data Base, selections can be made for certain areas of application, either to a specific plant or to parts of the plant modified after original design and construction. Various selections can be saved and kept up-to-date in parallel with the overall data base. Furthermore, selections and groupings can be set up for engineering subjects and activities of interest for any situation. Naturally, combinations of keywords, either present in the title and correlated subjects or as a separately assigned keyword, can also be used to extract certain codes and standards.
The data base has been set up in Access for Windows 95, as part of the Microsoft Office package. It is very user-friendly and can be set up and utilised without special training.
There is a great flexibility in the management of the data base. Apart from adding new codes and standards and modifying existing document records, there is the possibility of changing correlation details and introducing entirely new correlation schemes. Any number of selections with various levels of sub-selections can be saved while keeping the overall data base in the background. At all times consistency between the overall data base and specific selections is maintained.
The data base has its own internal quality assurance regime by specifying per record or group of records a “made, check, approve” block and a reference to the source where the information came from. Older records are kept in the data base alongside revisions of records, such that a transparency is obtained in the build-up of the data base. The updating process of the data base can be done on individual records or on groups of records to facilitate input work while improving consistency of data.
With the LDB a comprehensive set of references to codes and standards is available by which selections of codes and standards applicable to a wide range of situations can be performed expediently.