The preparation of the BIS is a complex undertaking that requires the integrated contribution of a multidisciplinary group of experts covering the various disciplines involved in a nuclear project (e. g. licensing, nuclear safety, nuclear, mechanical, electrical, instrumentation and control (I&C), civil-structural, procurement, construction, commissioning, operation and maintenance, quality assurance (QA), legal, contracting, commercial, financ­ing). Depending on the experience available, the owner’s organisation and the availability of the required resources, the BIS may be prepared either by the owner’s own personnel or with the assistance of an experienced outside architect-engineering (A/E) or consultancy company.

In the event that an external A/E or consultancy company is used, it should act in an advisory role. This means that it is highly recommendable that a parallel owner’s team supervise, review and follow up the work per­formed by the external companies assisting the owner with the BIS prepara­tion and take final responsibility for the decisions taken.

The composition of the team preparing the BIS will depend on the con­tractual approach. For a plant to be contracted on a turnkey basis, a team composed of 20 to 30 experts should be sufficient. The more segregated the procurement approach for plant acquisition, the more effort will be required on the part of the team. If the plant is contracted using large, split-package contracts (e. g. the NI separate from the TI), however, although the process would take longer, the resources required would not be substantially greater.

Six to eight months is a reasonable period for preparing the BIS. This would include the preparation of BIS criteria by the owner, preparation of several drafts of the BIS documents by the external A/E, review of the draft documents by the owner, and incorporation of the owner’s comments into

the documents by the A/E. This process is completed by a final review and

approval of the complete BIS by the owner’s management in time for

issuing the BIS to prospective vendors.