Nuclear power in Menghe

History

See also: Menghe and weapons of mass destruction

In 1968, four years after the end of the Menghean War of Liberation, the government of the Democratic People's Republic of Menghe established the state-owned Menghean Nuclear Power Corporation (MNPC), which was tasked with surveying the country's territory for possible uranium deposits, constructing uranium enrichment facilities, and developing a domestic nuclear reactor.

General-Secretary Sim Jin-hwan was a major supporter of nuclear power for peaceful purposes, and under his leadership the MNPC increased its research and development efforts. The country secured permission to import a 4-Megawatt research reactor from Letnia in 1972, and brought it online in 1976. In 1978, the country began work on a domestic research reactor, which came online in 1983. Neither of these reactors were hooked up to the national power grid; their main purpose was to build domestic experience with reactor design, and to produce radioactive isotopes for Menghe's nuclear weapons program.

In 1982, agents of the Menghean government covertly opened back-channel negotiations with Ostland, whose military was rumored to be seeking data on nuclear weapons development to oppose the threat from Sebrenskiya. The two sides reached a secret agreement under which Menghe would share a steady stream of data from its nuclear weapons program, which was still a tightly kept secret at the time. In return, Ostland would export two nuclear reactors to Menghe, and share information relating to civilian nuclear power plant design. Construction of the first reactor, a 600-MWe Generation II PWR at Byŏkdong County in Anchŏn, began in 1983, and its twin began construction the following year. Following the November 4, 1984 nuclear test at Naran Gaja, the international community placed Menghe under an embargo for its violation of the STAPNA agreement, stalling construction work at both reactors. Even after Ostish engineers had left Menghe, however, the two countries continued to secretly trade test data for civilian nuclear blueprints in 1985 through 1987, allowing work on the Byŏkdong facility to continue at a reduced pace.

Following the Decembrist Revolution, Choe Sŭng-min's government ordered engineering teams to resume work on the Anchŏn plant, which was linked to the civilian power grid in 1992. Construction also began on civilian nuclear plants near Sunju and Yŏng'an, as part of a twenty-year plan to bring one civilian reactor online each year. This program focused on placing new nuclear power facilities on the Chŏllo plain and Meng river basin, which were far from coal-producing areas but were experiencing rapid economic growth.

Accelerated construction schedules and the rapid transition from experimental reactors to civilian power stations led to serious safety issues in Menghe's first set of Generation II reactors. Following the Chimgu nuclear accident in 2003, the General-Directorate for Energy shut down all operational reactors and instituted a temporary freeze on all new construction so that inspectors could review the causes of the Chimgu accident and draw up a list of safety corrections.

Construction resumed in 2006, after the report was finished, and retrofits of existing reactors began in the same year. During the temporary shutdown, coal power had filled the vacuum created by Menghe's ballooning energy needs, contributing to serious air pollution issues in major cities. Despite higher public opposition to nuclear power, the Menghean Socialist Party doubled down on its commitment to expanding the nuclear sector, aiming for 30% of the country's electricity to come from nuclear plants by 2030. By the late 2010s, the country was beginning construction on five new reactors every year, with a planned rate of ten reactors per year in the 2020s. Menghe has also emerged as a leader in the design of new nuclear reactor models, particularly models optimized for high safety and fuel efficiency.

Reactor models

Menghe operates a large number of different reactor models, the result of its reliance on international assistance and its turbulent development program. Additionally, because of the multi-stage construction and contracting process, many individual nuclear power plants contain a combination of different reactor types, usually with pairs of matching reactors introduced two by two across different time periods.

Domestically built Menghean reactors are designated "Ro" (로 / 爐), short for "nuclear reactor" (Menghean: 원자로 / 原子爐, wŏnjaro. Where "Ro" is used alone, the reactor is a pressurized water reactor, with the exception of Ro-1 and Ro-2, which were experimental gas-cooled units. Later types add modifiers to the designation: NR-600, for example, is a sodium-cooled fast reactor (나트륨냉각고속원자로 / 나트륨冷却高速原子爐, Natryŭm Naenggak Gosok Wŏnjaro).

Ro-5

The Ro-5 was Menghe's first civilian nuclear reactor. It was a licensed version of an Ostish Gen-II PWR design, built using a combination of domestically manufactured and imported components. Two were built, both at the Byŏkdong Nuclear Power Plant in Anchŏn municipality, in the late 1980s. At full capacity, each reactor generated a net output of 640 MWe of electricity. Construction stalled during the economic crisis of the late 1980s, but resumed in the 1990s.

Ro-5G

The Ro-5G, with G denoting "improved" (개선 / 改善, Gaesŏn), is a Menghean domestic improvement of the Ro-5 reactor, designed during the late 1980s and early 1990s. Its development benefited heavily from blueprints and technical information illicitly transferred from Ostland during the late 1980s, but as Ostland's government publicly denies any involvement, Menghe claims the reactor as a domestic design. The first reactor began construction in 1994, and it started operation in 1999, before the first 900 MWe design.

Like the Ro-5, the Ro-5G is a Gen-II pressurized water reactor with three coolant loops: a primary loop running through the reactor core, a secondary loop linking the primary heat exchange to the turbine, and a tertiary loop using water outside the plant to cool the secondary loop. The original 1970s-vintage control room equipment was retained, and many of the supporting systems were simplified in a bid to reduce costs. Net power output was also increased to 660 MWe. Eight reactors of this type were ordered, but due to safety concerns following the Chimgu nuclear accident, one was cancelled before construction, one was cancelled mid-construction, and one was rendered inoperable by a partial meltdown. The two existing reactors also underwent major safety refits, and the three under construction were modified to meet higher standards. As of 2019, the five surviving reactors remain in operation, and plans to deactivate them have been postponed in order to help meet air quality targets.

CP1

In tandem with the development of the Ro-5G reactor, Menghe ordered four 900 MWe reactors from Sieuxerr as an alternative measure in case work on the Ro-5G did not go as planned. The CP1 model selected for construction included some improved safety features, such as an emergency pump system to spray tertiary-loop water into the containment building, and matched two reactors to a single control room. Net electricity output was 944 MWe per reactor.

All four CP1 reactors were built at the Wando-Changjang facility, which serves the southern city of Sunju. They began construction in 1992, 1995, 1997, and 1999, but the first unit did not link up to the power grid until 1999, after the first Ro-5G reactor was online. Two more reactors of the type were still on order in 2003, but Menghe froze the contract in 2003 to conduct a comprehensive nuclear safety review. The contract was cancelled permanently in 2005 due to the deterioration of Menghe-Sieuxerr relations. Cancellation of the contract also interfered in the supply of Sieuxerrian-made parts to the second two reactors, which resumed construction in 2006, forcing Menghe to substitute foreign-made and reverse-engineered components. As such, despite their official CP1 designation, Reactors 3 and 4 at Changjang were completed to a slightly different standard, and differ in their output levels. Reverse-engineering work on these reactors served as a bridge to the development of the Ro-900 reactor, which began construction in 2009.

ABWR

After the lifting of the moratorium on new reactor construction in 2006, Menghe could no longer rely on components supplied from Sieuxerr. Instead, it turned to Dayashina, ordering two 1300-MWe ABWR reactors for a new power plant in Daegwan county. Construction began later that year, based on negotiations made the previous year. Though the ABWR came with a much higher price tag than the CP1, it also generated more electricity at peak capacity. More importantly, it came with a wide array of new safety features, including passive safety features designed to shut the reactor down automatically and greatly improved coolant pumps within the reactor pressure vessel. Menghe ordered two more ABWR reactors in 2008, bringing the total at the Daegwan plant to four.

Though it carried the highest hopes, the ABWR design proved to be something of a disappointment. Construction work ran into delays and cost overruns, particularly on the first reactor. Once operational, the ABWR reactors also suffered from poor reliability levels, as they often had to be taken off the grid for maintenance. From activation until 2018, the four ABWR reactors at Daegwan were off the grid 32% of the time, compared to 9% at the four CP1 reactors. As a result, subsequent Menghean Gen III reactor design opted for more reliable approaches.

HAL

To complement the Dayashinese reactors, Menghe ordered four more nuclear reactors from Hallia. Like the ABWR units, these were ordered in two groups of two, with construction beginning in 2006, 2007, 2008, and 2009. These were all Generation II reactors with a PWR design, though they incorporated more safety features than the Ro-5 and 5G, and had a higher power output.

V-412

The V-412 was Menghe's third foreign-designed reactor built during the late 2000s. It was an imported Sebrenskiyan design, based on the VVER-1000 water-water energetic reactor family developed in Letnia. Two reactors of this type were ordered, and ironically, both were built at the Byŏkdong power station, alongside the Ro-5 reactors purchased from Ostland in return for covert support for its standoff against Sebrenskiya.

See also

• Chimgu nuclear accident
• Menghe and weapons of mass destruction