China’s Qinshan III nuclear power plant – the country’s first Candu unit – is now on-line. Construction and project management techniques used during the plant’s construction enabled a number of records to be set, and mean that the plant now serves as the Candu 6 International Reference Plant.
Dr. Kenneth Petrunik, Atomic Energy of Canada Ltd.,
Naranjan (Nar) Goel, Bechtel Power Corporation,
Ryuzo Masuoka, Hitachi, Ltd., Power Systems
The Qinshan III Candu nuclear power plant consists of 2×728 MWe units constructed by Atomic Energy of Canada Limited (AECL) and its partners Bechtel and Hitachi with the Third Qinshan Nuclear Power Company Ltd. (TQNPC). The project is located in the Qinshan area, Zhejiang Province, Peoples Republic of China on the shore of Hangzhou Bay off the East China Sea, approximately 126 km southwest of Shanghai. The plant was built in the nuclear power complex that already has three Pressurized Water Reactors (PWRs) operating, one 300 MWe (Qinshan I) and 2×600 MWe (Qinshan II).
Candu (CANada Deuterium Uranium) 6 is a nuclear reactor that uses natural uranium ore to safely produce heat for power generation. It uses heavy water (Deuterium or D2O) as a moderator and coolant. The reactor can be refuelled while on line at full power. This is a two loop (primary and secondary) plant similar to the PWR. The Candu 6 is rated for 2063 MWth.
The balance of plant (BOP) for Qinshan consists of a 728 MWe turbine-generator, associated steam cycle equipment, an auxiliary boiler, and a water treatment plant with ultra-filtration, reverse osmosis and demineralizer equipment. The turbine comprises a dual flow high pressure (HP) section, two moisture separator re-heaters (MSR) and two low pressure (LP) sections, and a surface condenser cooled by seawater. The feedwater is regeneratively heated in six stages (two HP and four LP stages).
The contract effective date for the Qinshan Candu nuclear power plant was February 12, 1997 and first containment concrete for Unit 1 was June 8, 1998. Unit 1 went into service on December 31, 2002, some six weeks ahead of schedule and Unit 2, July 20, 2003, some 16 weeks ahead of schedule. The project cost was less than the original budget.
Figure 1. The Qinshan units are the first Candu units in China
The Qinshan Candu units are the first Candu plants in China and have been constructed to the shortest construction schedule of any nuclear power plant built in China. The reasons for this are modern project management tools and construction methods that included heavy lifts and modularization, improved design, together with an excellent working relationship and partnership between TQNPC, the Chinese subcontractors and foreign project participants (AECL of Canada, Bechtel of the USA and Japan’s Hitachi).
Wolsong 3 and four Candu 6 units in the Republic of Korea were used as the reference plant design for Qinshan. For Qinshan III, TQNPC implemented specific design improvements from the reference plant. The Qinshan III project was financed on a sovereign credit basis utilizing Canadian Export Development for AECL supply, Japan Bank for International Cooperation (former Export Bank of Japan) for Hitachi supply, the Export Import Bank of the United States and Export Credits Guarantee Department of the United Kingdom for Bechtel supply.
AECL as overall project manager, designed and supplied the nuclear steam plant (NSP) and managed NSP construction. NSP equipment supply was subcontracted, in part, to Canadian, US, European and Korean suppliers. A consortium of Bechtel/Hitachi provided BOP design and supply under subcontract to AECL. Bechtel provided the overall engineering and procurement of the BOP, and Hitachi provided the design and supply of the turbine-generator, and auxiliary equipment including feedwater heaters, condenser, and so on.
Hitachi also supplied some of the NSP equipment, such as nuclear motors. TQNPC, as owner, managed the BOP construction and executed commissioning. Construction was by Chinese construction contractors: China Nuclear Industry 23rd Construction Company (CNI 23), Hua Xing Construction Company (HXCC), China Nuclear Industry 22nd Construction Company (CNI 22) and Zhejiang Thermal Power Construction Company (ZTPC).
TQNPC’s role included: providing site preparation and access; permanent site facilities (offices, warehouse) at the start of construction for improved productivity; managing BOP construction by subcontract to Shanghai Nuclear Engineering Research and Design Institute, with technical assistance by Bechtel/Hitachi; providing local staff to AECL Site Project Management Organization; managing licensing; providing Quality Surveillance (QS) of NSP and BOP offshore equipment during manufacturing; providing added site QS of NSP construction through an independent QS company; executing commissioning with guidance and direction by AECL and providing fuel after the first fuel load (China has established the capability of manufacturing Candu fuel).
AECL’s role covered: overall project management; design and supply of NSP equipment; site management by subcontract with Canatom NPM (Canada); training by a subcontract to Hydro-Quebec (Canada) Gentilly 2 Candu 6 station; design and supply of BOP equipment by a subcontract with Bechtel/Hitachi; NSP construction and site excavation by subcontracts to Chinese construction contractors; supply of initial load of fuel and heavy water, and guiding and directing commissioning. Bechtel and Hitachi staff were also extensively involved in the ‘guide and direct’ function during the construction and commissioning of BOP systems and components.
Project management tools
The project featured state-of-the-art engineering tools: the Candu Material Management System, which identified and tracked equipment and material from the design phase through the supply chain, to construction and operation of the station; Asset Information Management (AIM) which managed, on line, all formal project records in electronic format; an electronic document control system; a Weld Information System (WIS) developed by CNI 23 to electronically record quality information of all pipe welds; Primavera P3, a planning and scheduling tool. AECL, Bechtel, and Hitachi used CADD systems as a design tool for the plant. These tools were integrated for maximum benefit, improved quality and efficiency.
TQNPC as owner supported the use of the new electronic tools, which contributed to the successful management of the project. The simplification of storage, accessibility, and upgrading facilitated configuration management from design to construction and operations – all to the benefit of project stakeholders. Because of these tools, the as-built condition of the plant was well defined and documented. This will ensure that problems are easily identified and corrected, and that the configuration of the plant is maintained properly, during operations.
Construction of the plant was carried out by Chinese contractors. Excellent co-operation among AECL, Bechtel and Hitachi, TQNPC and Chinese subcontractors resulted in the introduction of modern construction management techniques, some of which had not been previously used on other Candu projects.
Open top construction was implemented for the first time on a Candu project by TQNPC, AECL, Bechtel and Hitachi with a very heavy lift crane (Liebherr 1650/1800) supplied by TQNPC which provided schedule flexibility and reduced labour, and allowed work access from top and bottom.
TQNPC was responsible for BOP construction management. A key feature of the site was four undersea intake cooling water ducts (designed by Bechtel) averaging 50 meters long that were constructed under water. The Qinshan site is located on the Hangzhou Bay, which comprises high silt content and current velocities reaching 4 m/s with the daily tidal inflow and outflow. The limited visibility and high currents made the installation extremely challenging. Bechtel built a detailed pump house model and extensive testing with silt was performed to confirm the design. This very difficult work was completed by TQNPC and Chinese contractors to support the project schedule.
A special challenge on Qinshan III was the small site with water on three sides. Some of the site area had to be created using retaining walls, which limited space especially in the first part of the project. The restricted access required detailed planning and coordination of common systems in the ring trenches around the site to meet the schedule. Another success of the project team was the achievement of the lowest leak rate recorded for CANDU 6 containment from the Unit 1 reactor building leak rate test. Lessons learned on Unit 1 reduced that even further on the second unit. The learning experience was visibly demonstrated in going from Unit 1 to Unit 2, with construction durations for many Unit 2 activities being significantly lower than for Unit 1.
The quality assurance programme at site was under AECL’s umbrella and was implemented to meet both ISO 9002 and Canadian Standards Association requirements. Construction contractors implemented quality programmes to international standards and used quality trend analysis to improve their work. Significant improvements occurred from the start of the project through to the construction and commissioning of Unit 1. Lessons learned on Unit 1 were applied on Unit 2, resulting in improved quality, fewer errors and shorter schedule duration.
The Qinshan Candu project represented the first Candu constructed in China and with Qinshan Phase III being built on a small site surrounded by water on three sides. The detailed planning and strong project management presented a unique challenge for the project.
A number of world records were set by Chinese NSP Contractors CNI 23 and HXCC during the construction of the plant. These are shown in Table 1.
The China-Canada partnership successfully integrated the multi-national project expertise of the participants on the Qinshan Candu project and evolved Candu 6 construction methods and design. TQNPC and Chinese construction contractors adopted advanced project management methods and tools. Improved construction technology, coupled with hard work, achieved many installation world records. TQNPC, AECL, Bechtel and Hitachi and the construction subcontractors working together achieved a world concrete to 100 per cent power. construction schedule record for the first-of-a-kind nuclear power plant in any country – 51.5 months from first concrete to criticality and 54 months from first concrete to 100 per cent power.
Qinshan III will become the Candu 6 International Reference Plant and its construction advances will allow continued improvements for future ‘replicated’ and ‘evolved’ (enhanced modularization) units including the new Advanced Candu Reactor where the same partnership of AECL and Bechtel-Hitachi are looking at international opportunities including the USA, Canada and China.