1.1. BACKGROUND
With several nuclear power plants (NPPs) presently under construction worldwide, expectations are rising regarding the quality, cost and schedule associated with the construction of new NPPs. Worldwide experience in large construction projects, including NPP projects, has resulted in significant advancements in construction techniques and methods.
This includes advances in the following areas:
— Integrated project planning and management
— Design control is validated by continuous review of a project schedule for implementation and verification of critical and subcritical paths.
— Deployment planning
— Information and data management of design, schedule, cost, procurement, personnel and job status information;
— Control of inventory and movement of construction personnel, material, tools and equipment, including use of radiofrequency identification (RFID) devices, global positioning system (GPS) tracking and in-camera surveillance;
— Construction efficiency, including use of an alphanumeric Work Breakdown Structure (WBS) that identifies all structures, systems and engineered components by building-level-area/system-class-code (BLA/S-C-C).
— Site construction infrastructure and layout for construction
— Methods and equipment for movement and lifting of large modules and very heavy equipment;
— Construction personnel mobility.
— System and room modularization and placement;
— High deposition rate welding technologies and overall reductions in the number of critical welds;
— Insulation and lagging.
— Electrical and controls installations
— Electrical cable placement and splicing technologies;
— Plant data and controls networking installations.
— Inspection, testing and acceptance criteria management
— Robotic and remote inspection;
— As-built information management.
Subsequent sections and paragraphs of this publication address each of the areas. A summary discussion is provided of the historical approaches used in previous NPP construction projects, followed by a discussion of current best practices used in the nuclear power arena and other large construction projects. In Appendix I of this report, an outline similar to that above is used to assemble a catalogue of current and near term methods, techniques, tools and applications that may be used to advance complex multidisciplinary construction projects.
Another parameter that is critical to mega-projects is the overall plant cost, including (a) owner’s costs;
(b) direct costs of plant buildings and equipment; (c) the cost of financing; and (d) the cost of skilled labour during construction. If the construction schedule can be reduced, both the financing and the labour costs involved in
construction will usually be lowered. Similarly, improvements in the efficiency of skilled labour have a significant impact on cost.
The initial construction techniques used for NPPs were adopted from fossil power plant construction experience in the industrialized countries. However, considerable development and improvements have been achieved in this area since the first NPPs were constructed. The development was primarily driven by the need to achieve optimized construction schedules whilst meeting stringent regulatory requirements and achieving high quality.
To achieve competitive costs for NPPs, it is important that the construction be carried out on the optimized schedule with the most efficient use of construction labour and materials resources. Recently completed NPP projects and those currently under construction can give good insight into various means of achieving an optimum and efficient construction schedule. Lessons learned in constructing large, non-nuclear projects can also be of great value in planning new NPP construction.
Currently, work is ongoing worldwide to develop various techniques to improve plant design, ensure the quality of construction, and reduce the time taken to construct NPPs. This report provides Member States with information related to current and advanced construction technologies that can reduce construction costs and optimize the schedule for future NPPs. Global experience is consolidated and presented by incorporating insights from a variety of technology improvement programmes.
Nuclear plant construction techniques are not dependent on nuclear steam supply system (NSSS) technology.
While different NSSS technologies may have unique equipment or systems that will require special installation instructions, the basic construction techniques remain the same regardless of the NSSS technology. For example, full site development, including site preparation, is an essential prerequisite for the successful commencement of power island work. It is recommended that all horizontal, vertical and, most importantly, underground utility construction tasks are integrated to enhance timely, free and unimpeded access. Full site integrated planning and development will also reduce peak site personnel power and focus the efforts on the critical and subcritical paths.
Most of these techniques are also used for other large construction projects, regardless of the commercial or industrial purpose of the project. Due to the predominance in power plants of piping, large equipment, large vessels and control equipment, power plant construction projects are closely related to petrochemical refinery and process construction projects. Techniques and technologies discussed in this report are applicable to all types of light and heavy water cooled NPP construction, unless specifically indicated.
1.2. OBJECTIVE, SCOPE AND INTENDED AUDIENCE 1.2.1. Objective and scope
The objective of this publication is to describe the activities and associated technologies for construction of NPPs by assimilating global experience from a variety of construction projects. The scope involves collecting experiences from recent projects that will be relevant to new projects in the near term.
The comprehensive description of construction activities and associated construction methods given in this report is intended to be useful in planning deployment of new NPPs, both in industrialized and in developing Member States.
It is intended that in the future, this publication can be used and extended to:
— Identify activities that could be conducted by the Member States’ local labour force and domestic industry;
— Form the basis for examining lessons learned in recent construction projects;
— Plan development of human resources and industrial capability.
Note that this report does not address advancements in best practices relative to design, licensing, regulation and operations of NPPs.
1.2.2. Intended audience
The intended audience includes managers and technical staff involved in the planning and construction of new NPPs, as well as government officials in Member States that are considering building new plants.
1.3. PREPARATION AND STRUCTURE OF THIS PUBLICATION 1.3.1. Preparation
The approach used to prepare this report was to collect the experience of experts in plant construction regarding the activities carried out during the construction process, and the construction methods for performing each activity. Information from recent studies, including those documented in References [1–4] were also incorporated.
1.3.2. Structure
This report is structured as follows:
— Section 1 provides an introduction to the report; outlines the objectives and scope; and describes its intended audience;
— Section 2 describes, and gives the rationale for, the grouping of buildings and structures;
— Section 3 presents the pre-project and site infrastructure activities during construction;
— Section 4 deals with construction activities of general applicability to all buildings in a plant;
— Section 5 addresses construction activities and methods specific to Group A buildings (nuclear island);
— Sections 6 and 7 address construction activities and methods for Group B buildings (turbine island) and Group C buildings (Balance of Plant), respectively;
— Sections 8 and 9 are dedicated to modularization technologies and the open top construction methods, respectively;
— Section 10 discusses the construction quality assurance (QA) inspection and testing activities;
— Section 11 discusses integrated project planning and management activities;
— Section 12 summarizes the publication and presents a conclusion;
— Appendix I contains a survey of technologies for NPP construction;
— Appendix II provides a suggested building list;
— Appendix III shows an example of a planning activity chart.
A list of all the abbreviations used in this report is provided at the end of this publication.