Ulchin Units 5 & 6 Set the Stage for
Making Korea a Nuclear Powerhouse
Strengthens overseas presence after using Korean technology

Ulchin Nuclear Power Plant Units 5 & 6 are put into operation, churning out electricity at Bugu-ri, Buk-myeon, Ulchin, about 300km southeast of Seoul, adding to the scenic nocturnal landscape of the East Sea. "It took a long period of time - more than a decade - for the nuclear facilities to make their debut after overcoming difficulties," Min Gye-hong, senior vice president of Korea Hydro & Nuclear Power Plant Company (KHNP) Project Division, said.
Take a look into the nuclear units, which are expected to serve as a catalyst to help the domestic nuclear power industry flex its muscles in overseas market, on the occasion of a ceremony for officially marking the completion Aug. 11 with the residents in the neighborhood participating.
Rhee Chong-chan, project manager of Ulchin Units 5 & 6 Department at KHNP, gives a detailed account of the construction process ranging from planning and start-up operation. He still recalls the numerous episodes concerning overcoming the difficulties which the project had experienced, particularly during the Asian financial crisis in the late 1990s.
The project appeared to make smooth sailing on an initial stage: the master plan for the construction of LWR-type, 1,000 MW-class nuclear facilities was established in September 1994, deals on the supply of reactors and turbine generators as well as their design were concluded, respectively with Doosan Heavy Industries and Korea Power Engineering Company (KOPEC) in November 1996, and an agreement on the joint construction work with three construction companies - Dong Ah, Doosan and Samsung - was reached in April 1997.
"All went smooth with the goal of breaking ground on the originally set time schedule - October 1997. However, things had turned into an unpredictable situation as the Asian financial crisis dealt a heavy blow on the Korean economy" Rhee said. Even KHNP had to raise financial soundness, with a projection of a drop in electricity demand stemming from the economic downturn.

Shortest period in history of
nuclear construction

The government once considered a delay of the project by more than two years, but finally decided to put off it 15 months at the request of the parties involved and the residents. The decision was made thanks to the involved parties?joint efforts to cope with the difficult situation at that time. Design contractors, equipment and materials supplier and construction companies joined forces and urged the concerned authorities to push ahead with the project at an early date. The residents in Ulchin also joined them in filing an appeal for an early ground-breaking of the projected nuclear units with concerned authorities. After tiding over such a hitch, Ulchin Units 5 & 6 broke ground in time with the dedication of Ulchin Unit 3 in September 1998.
Once the construction was launched belatedly with much difficulty, the parties involved had a mission to complete the project in time. It took about 55 months for Units 5 & 6 to be dedicated after the first placement of concrete, achieving a feat - the shortest period in history of nuclear construction. To this end, the participants had to do their best in their respective fields. Meetings for dedicating the project on schedule were held on a regular basis - once each month - to sort out problems and solve them. A Project Review Meeting in which all of the participants, ranging from executives and working-level officials, assessed the process so far and checked an implementation plan for the next six months was also convened every half year. The participants took time out to conduct "joint exercises" like mountain hiking in a bid to show solidarity, raise a spirit of cooperation and develop teamwork among the entire group.
One of the important things for the dedication of the units was about acquiring licenses from the government. Given the fact that licenses and permissions like construction permit of the predecessors hit a snag due to opposition by neighborhood residents and local administrative authorities, those of Units 5 and 6 were given the green light under a special law governing the development of rural districts. The local autonomous body issued the permits for Ulchin Units 3 & 4, adjacent to Ulchin Units 5 & 6 under their separate laws. Those of Units 5 & 6 were given the go-ahead by the central government by invoking the approved implementation plans on Ulchin Units 1 and 2, a move designed to overcome the difficulties related to the permission process of the local autonomous body in accordance with separate laws.
The construction permit for the placement of concrete was issued by the Ministry of Science and Technology in May 1999, enough time to make full preparations for the placement of concrete five months later, contributing to setting a solid foundation for milestones of the construction process.
Contracts on the construction of the units?major facilities were signed with three construction companies for the first time in Korean history of nuclear construction. Unlike worries over a possible failure to coordinate duties among the three, the contractors had synergetic effects by competing in introducing advanced construction methods and better on-site management techniques, and sharing information on construction.
The construction firms operated their joint on-site management organization, dubbed the "Integrated Construction Management Office" designed to examine interferences and raise construction efficiency.
The Nuclear Power Construction System (NPCS) was also introduced to share information on construction and ensure the efficiency of project management. NPCS allowed working-level officials of the site to obtain the blueprints and materials, produced by designers in real time, thus reducing waiting time and saving overall management costs.

Bankruptcy and labor unrest

Dong Ah, one of the three construction firms, went bankrupt, touching off a series of requests for temporary seizures of the construction money starting from tax authorities. Payments of subcontractors and wages of Dong Ah workers were made under the changed payment method on the site and steps designed to ensure a stable material supply were in place to preempt work stoppages. A conflict on the payments ensued at Dong Ah's Cheonan factory, the supplier of steel and construction materials used for the construction of turbine structures. Several rounds of negotiations with the factory leaders succeeded in agreeing to make payments in cash to solve the issue. Dong Ah, the domestic exclusive supplier of Pre-cast Concrete (PCC) pipelines also faced the project with a possible supply disruption. An impasse was avoided by agreeing to payments in cash. If it went awry, ordering them overseas could have lead to exorbitant prices and a construction delay. Though workers of Dong Ah equipment suppliers and subcontractors demonstrated around the sites in protest against the wages in arrears, KHNP created an atmosphere in which laborers at the lowest echelon felt at home while working by promising direct payments to subcontractors.
Unionists of KOPEC, in charge of overall design, went on a strike in February 2002 to put up opposition against the privatization of KOPEC. Steps were taken to prevent any possible disruption of construction and manufacturing auxiliary instruments, on which a stoppage of design could have an impact. Designs were rescheduled in accordance with priority, while company executives, non-unionists, carried out equipment technology assessment and other jobs and striking unionists were persuaded to perform the job related to urgent design work.
Labor problems struck Doosan Heavy Industries & Construction Co., the manufacturer of reactor and turbine generator as the company underwent a restructuring following its privatization. Even the labor unrest could have disrupted any supply of equipment and materials, but it did not have a big impact on the construction process due to thorough preparedness on the site and Doosan's redoubling efforts to make it on schedule after returning to normal after the labor unrest.

Conclusion of the agreement with residents
Fishermen in the neighborhood put up strong resistance against the installation of submerged discharge facilities designed to reduce the level of the water the six units discharge into the sea to that of the previous four units, as KHNP was going to hold a hearing session on the issue in accordance with an environment impact assessment. They demanded compensation for damages to fishing farms, claiming that an initially commissioned survey, conducted by Kunsan National University indicated negligible impact from the discharged water and did not pay proper heed on the compensation. Negotiations on the compensation with fishing representatives were held on more than 50 occasions to agree on the resumption of the work on the installation of the submerged discharge facilities. Both sides finally reached an agreement with a win-win strategy, calling for diverting commission charges into compensation fees for fishermen, but not carrying out a separate survey on the damages.

Start-up operation
Ulchin Unit 5 had successfully underwent such major tests as Cold Hydro Test, High Functional Test and Fuel Loading earlier than scheduled thanks to dedicated efforts on the part of those responsible for start-up operation, since the commencement of start-up operation in July 2000. Power ascension test appeared to make a good sailing, riding on the good results of previous tests. However, signs of a detachment of the thermal sleeves of Ulchin Unit No. 5 were detected, and a further examination showed that one thermal sleeve was detached and three others were experiencing a detachment process. The outcome of assessments by such overseas institutions as Westinghouse, Framatome and TUV concluded that a removal of the sleeves had nothing to do with safety. Such an accident was reported during the trial operation of Palo Verde Unit One in the United States whose design model was identical to Ulchin Unit 5. Residents and representatives of antinuclear organizations were allowed in to make naked observations so as to ensure a transparent operation of nuclear plants. The thermal sleeves of Units 5 and 6 were completely removed after obtaining permission from the regulatory agency.
Following the resumption of the start-up operation in May 2004, the power ascension test continued on Unit 5 and it were finished in a successful way. A four-hour-long experiment on the House Load Operation proved an assured performance of the turbine generator. The turbine generator was tested to have secured safety and trust in the case of an emergency, as it did not cause vibration ? a problem expected before the test. The good test results were due to close cooperation by a task force team manned by Doosan technicians and site officials.
The start-up operation of Unit 6, conducted at an interval of nearly one year, went smooth by capitalizing on the experiences of that of Unit 5, except for a delay of testing power generation control systems that led to the later-than-schedule issue of a permit on fuel loading.
The dedicated efforts by trial operation staff paid off. Ulchin Unit 5 was dedicated on July 29, 2004 after making up for lost time, caused by the thermal sleeve problem. Unit Six was completed on Apr. 22, 2005 after shortening the period from the first placement of concrete to dedication to a record of about 55 months in history of nuclear construction.
Units five and six have been proved to be upgraded versions in economical and safety perspectives. They are furnished with advanced equipment. Operation and maintenance systems of the newly opened nuclear power units are digitalized in a bid to improve efficiency. The fuel loading cycle has changed from 12 months to 18 months, maximizing plant utilization.
Annual permissible radiation levels have been lowered in accordance with global trends from 50mSv to 20mSv for maintenance workers and from 5mSv to 2mSv for the general public.
Welding pipelines of the reactor coolant has been completed in a record low of 205 days, compared with 219 to 261 days for the previous units, while Units 5 & 6 registered the lowest welding defect rate of 0.1 percent, compared with 5.51 percent to 6.0 percent for the previous units. Outdoor storage materials have been relocated to a common underground space so as to ensure construction efficiency by securing the passage routes for equipment and raw materials. An observation tour passage route has been set up so as to help visitors take a glimpse into the operation of nuclear plants.
Units 5 and 6, each with a power generation capacity of 1,000,000 kW, have brought to 20 the number of nuclear units in operation. They also raised Korea's total nuclear power generation capacity to 17,720,000 kW, ranking Korea as the sixth largest nuclear powerhouse in the world. The two nuclear power units increased the nation's power generation capacity to 60,990,000 kW, ushering in an era of 60 million kW in power generation capacity.
Unit 5 & 6 produce 15.2 billion kWh per year, having an effect of reducing some 12.8 million tons of greenhouse gases, compared to the production of the electricity using oil, helping Korea cope with the global pressure on climate change in the wake of the entry into force of the Kyoto Protocol.
Besides, the successful completion of Units 5 & 6 has once again demonstrated the superiority of the Korean Nuclear Standard Power, also dubbed "OPR1000" built by Korean excellent engineers with their own latest technologies, ranging from design to manufacturing, construction and start-up operation, paving the way for Korea to make a full-fledged entry into the newly emerging nuclear markets, including China and Vietnam, Indonesia and Romania. The units are expected to serve as a driving force behind the development of Korea. nw

Min Gye-hong, senior vice president of Korea Hydro & Nuclear Power Plant Company (KHNP) Project Division

The staff at Ulchin Unit 6 conducts a start-up operation of the Main Control Room of the nuclear power facility.

Crew members are at work about the installation of the turbine rotor for Ulchin Unit 5.