Value context and insight. lkm@koreatimes.co.kr
'Korea-developed APR1400 Shin Hanul provides stable power source'
Shin Hanul reactor 1 in Uljin, North Gyeongsang Province / Courtesy of Korea Hydro & Nuclear Power
By Lee Kyung-min
Commercial operation of Shin Hanul 1 to help with winter electricity demand
By Lee Kyung-min
ULJIN ― It took about four hours from Sejong, an administrative city south of Seoul, to Hanul Nuclear Power's headquarters in Uljin, North Gyeongsang Province, operated by Korea Hydro & Nuclear Power (KHNP), a state-run energy firm.
The eastern coastal city is where the Hanul Nuclear Power Plant is located. Shin Hanul unit 1 began commercial operation, Wednesday, 12 years after its construction began in April 2010.
The facility houses Hanul reactors 1-6, all of which are in operation. Shin Hanul units 3 and 4 will be built soon.
Security clearance was extremely tight to enter the premises. Reporters had to submit IDs before applying to join a guided tour organized by the state-run energy firm.
Cleared reporters were allowed in only after having their fingerprints checked. Without a temporary ID issued at the main gate, security officials blocked entry.
Electronic devices including cellphones and laptops were not allowed, due to security reasons.
The power plant is made of concrete. The structure stands 72 meters in height, equivalent to a 24-story apartment building. Its walls are 1.22 meters thick. No paint was used to add color, to better observe fine cracks on the outer wall with the naked eye. The doors there are heavy, and difficult to open, by design.
“The pressure system of the entire building is structured to make it difficult for radioactive materials to escape,” a KHNP official said. “The doors will not open easily, nor will they stay open.”
A further walk into the building led to the upper floor overlooking the main control room (MCR), where a six-member team of operators rotate every eight hours to maintain the key function of the fully digitized facility.
The newly built Shin Hanul, an APR 1400 reactor developed in Korea, has digital control monitors, unlike older models.
A group of reporters are on a guided tour of Shin Hanul unit 1 in Uljin, North Gyeongsang Province. Courtesy of Korea Hydro & Nuclear Power
Next was the turbine room, where electricity is produced.
Shin Hanul unit 1 is able to generate 1,400 megawatts (MW) of electricity per hour, after the water heated in the reactor moves to the steam generator.
The steam then propels the turbine blades to spin 1,800 times per minute, powering the generator installed at the ends of large turbine blades.
The turbine room generates 10,424 gigawatt-hours (GWh) per year, accounting for about 23 percent of the annual electricity demand of North Gyeongsang Province.
The next stop was made to help reporters understand how pellets, a fuel for nuclear power plants, work.
A pellet is a thimble-sized ceramic cylinder, about the size of an adult finger, consisting of enriched uranium.
One pellet can produce about 1,800 kWh of electricity, an amount enough for a four-person household to use for six months.
One fuel rod has 350 pellets made of zirconium alloy. Each rod is sealed at either end.
A total of 236 fuel rods are grouped together into a bundle, which then is used for about four-and-a-half years.
“Shin Hanul units 1 and 2 are the same APR1400 models we have exported to the United Arab Emirates (UAE),” a KHNP official said. “Their output capacity is up about 40 percent compared to previous nuclear reactor models, and the lifespan is up to 60 years, up 20 years.”