April 29, 2008 was a historic date for Korea as it marked the 30th anniversary of commercial operation of Kori 1, the first nuclear power plant in the country.
At the end of the 1960s when the scars of the Korean War still remained, and per capita gross national product was about $200, the investment of up to $2 billion, almost equivalent to four times of the government’s annual budget, was an irrational adventure to a country on the periphery of Asia. Thirty years since then, Korea now has 20 units of nuclear power plants in operation and eight units under construction or planned, providing 36% of total electricity. As such, Korea currently ranks the sixth in the world in terms of nuclear facility capacity.
At the beginning stage, the Korean nuclear industry entirely relied upon foreign contractors to build and operate the nuclear power plants. But it has grown significantly to the extent that it is now entering the world nuclear market with its own reactors and exporting the operational technology and skills to newcomers.
Korea has made breakthroughs in operational technology of nuclear power plants since Kori 1 started operation in 1978. This achievement can be demonstrated by the high capacity factors and low reactor scram rate without any significant nuclear incidents. The capacity factors in the early 1980s remained at only 40-60% due to our lack of experience, but from the beginning of 1990s it surged to the 80% range, and then stayed over 90% from 2000, about 10% higher than the world average.
Regarding the reactor scram rate, Kori 1 recorded 17 scrams in 1978. However, the occurrence was reduced steadily and stabilised at the rate of one scram per unit after the mid 90s. And since 2000, the occurrence of scrams is around 0.5 per unit per year. Korea has also maintained a good record in terms of safe operation: out of the International Atomic Energy Agency’s (IAEA’s) seven-level International Nuclear Event Scale, Korea has experienced a few Level 1 events and only one Level 2 event (and no higher level events).
These achievements are the result of constantly improved operation and maintenance technology as Korea has accumulated experience of operating five different types of reactor and power levels during the last 30 years. Improvement on capacity factor was made by continually decreased reactor scram rate, optimisation of outages and application of longer fuel cycles.
Likewise, the improvement in reactor scram rate can be attributed to not only accumulated experience in operation and maintenance, but also preventative maintenance programmes, which minimise system failures and provide best plant operational conditions, for example, by refurbishment of degraded components.
Such excellent operational records brought economic benefits and contributed to Korean economic growth. The capacity factor higher than the world average gave rise to the cost reduction of 7.5 trillion won in the construction of three 1000MWe-class nuclear plants. The electricity price rose by only 3.3% during the period of 1982 to June 2007 while consumer prices surged by 199%.
Achieving self-reliance
The history of Korean nuclear power construction can be described as an example of the pursuit of self-reliance in technology. In the early stage, we had to rely entirely on foreign companies, and construction projects were implemented by the foreign main contractors on a turnkey basis.
The roles of Korean companies were limited to site grading and levelling, procurement of materials for civil engineering and labour supply. Kori 1&2 and Wolsong 1 were constructed in this way.
Encouraged by the experiences gathered from construction of three units (including Kori 1), Kepco (Korea Electric Power Corporation) geared up self-reliance in construction technology and started a project on a non-turnkey basis. For Kori 3&4, Yonggwang 1&2 and Ulchin 1&2 projects, Kepco was responsible for 6% in architect engineering, 40% in equipment supply and 100% in construction.
In the Yonggwang 3&4 construction project, Korea took the leading role for the whole project and foreign companies participated as subcontractors. Then the turning point came when the Ulchin 3&4 units, the first Optimized Power Reactor 1000 (OPR1000, previously known as the Korean Standard Nuclear Plant), were built. For these units, the first standard plant design concept was introduced and applied to succeeding units. This clearly laid a foundation for Korean technological independence of nuclear plants.
Shin-Kori 1&2 and Shin-Wolsong 1&2, commonly called OPR1000+, are more improved in safety and efficiency than the existing OPR1000, and will be completed by 2013.
The indigenously-developed Advanced Power Reactor 1400 (APR 1400) will soon be built at Shin-Kori 3&4.
LILW disposal
Though the construction plan of the LILW (low- and intermediate-level radioactive waste) disposal facility was proposed in 1983, the Korean government’s efforts to select a site for the facility were halted by insufficient understanding of the public and strong political and social disputes.
In order to construct the facility, numerous political attempts were made and the social acceptance process was followed. After the long controversy, the government decided the selection process of the facility site would be based on voluntary application and local referenda. Then finally in June 2005, Gyeongju was selected as the LILW disposal facility site with overwhelming supports from the locals, among whom 89.5% voted for the plan.
Accordingly, the construction of cavern type waste disposal facilities which house a total of 800,000 drums started in November 2007 and now construction of two entrance tunnels is underway and expected to be completed by 2009.
Korea Hydro and Nuclear Power Company (KHNP) developed the world’s first LILW vitrification technology and is constructing facilities to vitrify low-level radioactive wastes generated from nuclear power plants in the Ulchin site. As a result, the volume of radioactive wastes from the Ulchin plant is expected to be reduced to one fifth of its present volume. This waste treatment technology is the most advanced one.
Lifetime extension
Kori 1, the first nuclear power plant in Korea, has a 30-year design life. To operate the unit beyond its design life, the refurbishment of the unit including replacement of degraded major components began in 1997 – ten years before the design life expiry date of 18 June 2007.
As KHNP launched a designated team to intensively prepare licensing documents in 2003, the government’s legislation process for the first plant life extension also started in parallel.
KHNP replaced most of the major components including steam generators, except for the reactor vessel and containment building. And it submitted to the government the application documents for the continued operation, satisfying periodic safety review and licence renewal requirements.
In addition, to obtain an objective review from an international organisation, KHNP applied for the IAEA’s peer review and was appraised as ‘excellent’, which meant no safety concern was found in terms of international standards.
The life extension of Kori 1 faced strong opposition from local residents and environmental groups, with no rationale for any real safety concern. So, all the staff of KHNP, from CEO to the newly hired, made every effort to gain the public acceptance and finally reached an agreement of life extension of Kori 1 with the residents through long-term dialogues.
An international industry
Agreements with residents on the LILW disposal facility site and life extension of Kori 1 are good examples of reconciliation of conflicting interests on long pending nuclear issues through open dialogue and democratic principles.
This June, Korean National Energy Master Plan to 2030, which covers the share of nuclear energy, construction of new units, high-level radioactive waste disposal and spent fuel storage facility construction, will be announced by the government.
The Korean nuclear industry will positively cope with such changes in circumstances and take this opportunity to earn the trust of people towards the nuclear power industry. In order to achieve the public consensus on the new nuclear programme, the open dialogues with the civilian and social communities are necessary for us.
The severity of global warming has led even environmental activists long opposed to nuclear energy to have favourable opinions on nuclear energy. This is a very encouraging sign to the nuclear industry along with international oil price increases.
Capitalising on this recent worldwide nuclear renaissance, many countries are actively considering the introduction of new nuclear power plants. Korea, as an exemplary case of nuclear operation, construction and technology independence, would like to share its long-term experiences and technology with the countries planning the construction of nuclear power plants.
KHNP is promoting overseas reactor export with its parent company, Kepco. The strong points of Korean reactors are accumulated world-class nuclear technologies through the construction, operation and maintenance of diversified nuclear reactors and strong nuclear infrastructure including construction companies, equipment suppliers, maintenance companies and fuel manufactures.
It is not an overstatement to say that our future in the 21st Century depends upon how we deal with energy and environment issues. Korea would like to take part in contributing to the development of mankind with nuclear energy as a sustainable energy source through positive technical cooperation with world nuclear industries.
Author Info:
Myung-Jae Song, Senior Vice President, Power Generation Division, Korea Hydro & Nuclear Power Co., Ltd., 411 Yeongdongdae-ro, Gangnam-gu, Seoul, 135-791 Korea
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