China’s 94‑minute Lufeng record: 261‑tonne dome installed on Hualong One

On a sticky October morning in southern China, a vast steel shell inched upwards over a hectic coastal building site.

At first glance it could have passed as another day’s work: a crane slewing into position, radios crackling, engineers glued to their monitors. But behind the steady tempo, China’s nuclear programme advanced in a strikingly tangible - and extremely heavy - way.

China’s 94‑minute feat at Lufeng

On 18 October 2025, crews at the Lufeng nuclear power plant in Guangdong province hoisted and set a 261‑tonne steel dome in only 94 minutes, placing it atop a Hualong One reactor unit. The piece is about 51 metres across and 13 metres tall - roughly the volume of a four‑storey block of flats.

The dome closes off the upper section of the reactor building and forms part of the containment system designed to keep radiation inside in the event of an incident. With the dome seated, the plant’s core structure is effectively “closes”, signalling that the main civil works have reached a late phase.

A 261‑ton dome aligned and locked in 94 minutes places Lufeng among the fastest large‑scale nuclear dome installations ever recorded.

Project staff likened the job to threading a needle using a crane. The lift had to be painstakingly controlled and continuously verified, even though the safe window for final placement was narrow. A meaningful offset would have meant lifting the dome back away, burning time and budget and potentially harming key structural interfaces.

A twin‑reactor project inside a much larger site

The headline‑making dome sits above Lufeng unit 6, one of two Hualong One reactors planned for the location. Even so, the overall development is far bigger than a two‑unit build. Once complete, Lufeng is expected to accommodate six reactors:

• two Hualong One (HPR1000) units, listed as units 5 and 6
• four CAP1000 units, based on Westinghouse’s AP1000 design

At present, the Hualong pair is furthest ahead. First concrete for unit 5 was poured in autumn 2022, with unit 6 following in 2023. From there, construction has proceeded through a tightly sequenced set of stages: base slab, reactor building walls, the internal concrete dome, installation of heavy plant, and now the external steel dome.

The internal concrete dome was installed in spring 2024, creating the initial protective barrier around the reactor. The newly fitted external dome now crowns that structure and establishes the final outline people associate with the reactor hall.

China’s planners are aiming for the Hualong units to enter commercial operation around 2028, subject to commissioning results and regulatory sign‑off. The CAP1000 reactors are progressing at a slower pace: two have only recently been approved, while two are still waiting for formal clearance.

Lufeng shows how China mixes two strategies on one site: an indigenous reactor design and a licensed evolution of a US model.

The Hualong One: China’s flagship reactor

The evocative name “Hualong” - often rendered as “resplendent dragon” - refers to a deliberately strategic engineering platform. Hualong One, also known as HPR1000, is a generation III pressurised water reactor with an electrical rating of about 1,150 megawatts. Depending on consumption patterns, that is enough to supply electricity to more than one million average Chinese households.

Its architecture draws on earlier Chinese CPR1000 units, then adds enhancements intended to strengthen safety and improve exportability. It incorporates layered, redundant safety systems, passive cooling features and a double containment arrangement combining concrete and steel. Digital instrumentation and control systems provide continuous monitoring, while emergency functions are designed with additional independence and diversity.

For Beijing, Hualong One is also a diplomatic and commercial export product. Two units are already running in Pakistan, and Chinese firms are actively marketing the design across Latin America, the Middle East and parts of Europe. Each build functions not only as generation capacity, but as a showcase supporting future export orders and long‑term service contracts.

How it compares to rival designs

Internationally, Hualong One sits among several generation III and III+ competitors. On paper their headline figures may look close, but they reflect different engineering approaches:

Reactor	Origin	Type	Power (MWe)	Containment	Approx. dome mass	First unit in service
Hualong One (HPR1000)	China	PWR	1,150	Double (concrete + steel)	~260 tonnes, ~51 m diameter	2021 (Fuqing 5)
CAP1000	China (under US licence)	PWR	1,250	Single steel containment	~660 tonnes, ~39 m diameter	2022 (Sanmen 1)
EPR	France / Germany	PWR	1,650	Very thick double containment	~320 tonnes, ~45 m diameter	2018 (Taishan 1)
AP1000	United States	PWR	1,117	Steel containment with semi‑spherical dome	~600 tonnes	2018 (Sanmen 1, China)
VVER‑1200	Russia	PWR	1,200	Double containment, Russian standard	~310 tonnes	2016 (Novovoronezh 6)
APR‑1400	South Korea	PWR	1,400	Double containment	~270 tonnes	2016 (Shin Kori 3)

Two observations are hard to miss. To begin with, Hualong One’s output places it mid‑range, while the overall footprint stays comparatively compact. Secondly, the dome is relatively light versus some Western counterparts, which can help compress build timetables while still delivering a double containment concept.

The crane that could lift a Boeing

At Lufeng, the day’s standout piece of kit was arguably the crane rather than the reactor. The site deployed a crawler crane rated in the thousands of tonnes. Put another way, it could lift a fully loaded Boeing 747 - though for this job, precision mattered more than raw capacity.

To land the dome, the lifting team had to rotate and lower it through minute corrections measured in millimetres. Engineers supported the process with dynamic laser guidance that tracked the dome’s position continuously. As wind, temperature shifts or mechanical effects nudged the steel shell, the laser readings fed into a control system that adjusted in real time.

The acceptable misalignment for the dome stood smaller than the thickness of a typical lighter, forcing operators to treat a 261‑ton part like delicate glassware.

With the dome held just above its final seat, technicians on the reactor building watched the clearances and relayed step‑by‑step instructions by radio. Only after every support and anchoring point matched up did the crew lower it into place, where welders and fitters later made the installation permanent.

Why speed matters for nuclear construction

Cutting hours - or even days - from a dome lift can seem superficial, but it directly affects costs. Nuclear builds lock up billions in concrete, steel and labour well before any electricity revenue arrives. Each month lost adds financing burdens and puts extra pressure on the supply chain.

Being able to repeat “critical lifts” such as reactor domes and containment modules quickly and reliably reduces those exposures. China has focused heavily on this, running large nuclear developments more like semi‑industrial assembly lines. Teams move between units using the same processes, equipment and quality checks, building competence and reducing unpleasant surprises.

That model differs from parts of Europe and North America, where many recent projects have struggled with delays and bespoke complexity. By standardising both reactor designs and construction steps, Beijing is aiming to lower unit costs - and to turn that advantage into a selling point domestically and internationally.

Part of a wider nuclear race

Lufeng’s achievement also lands amid an international contest to define the next phase of nuclear power. China is concentrating investment on large generation III stations, while the United States is pursuing a parallel route via small modular reactors (SMRs). Several US developers are working on factory‑built units designed to ship by road or rail, with ambitions for plants that could turn out dozens each year.

Russia, South Korea and France are following their own paths as well: export‑oriented VVER‑1200 programmes, APR‑1400 fleets in the Middle East, and EPR projects across Europe and Asia. Each participant is effectively betting that its design becomes the reference standard - securing decades of fuel supply, maintenance, and training arrangements.

Nuclear technology now functions as both infrastructure and foreign policy, tying host countries to suppliers for the whole life of the plant.

What this means for energy and climate

For China, the purpose extends beyond demonstrating engineering prowess. Electricity demand is climbing, air quality remains a challenge, and climate commitments are tightening. Coal still dominates the national mix, particularly in inland provinces. Large coastal nuclear complexes such as Lufeng help rebalance the system by delivering steady, low‑carbon baseload power close to major industrial centres.

A single gigawatt‑class reactor can avert millions of tonnes of CO₂ over its lifetime compared with comparable coal generation, depending on utilisation and which fuels are displaced. Nuclear output can also reduce exposure to imported gas at a time when prices are volatile and geopolitical risks are elevated.

The approach is not without compromises. Concentrating multiple reactors at one site concentrates risk too, and demands strong emergency planning, assured access to cooling water, and credible long‑term waste strategies. Communities nearby typically want straightforward answers on accident scenarios as well as tangible benefits, from employment to improved grid stability.

How a containment dome actually works

For readers outside the sector, the dome can feel almost like a symbol - a quick visual cue for “this is a nuclear plant.” In reality, it performs a defined safety function. The containment system, dome included, provides a pressure‑resistant envelope around the reactor coolant circuit. If a pipe were to rupture or fuel were damaged, that envelope is intended to keep radioactive material from travelling far beyond the building.

In the Hualong One configuration, the inner concrete structure and the outer steel shell share this duty. Thick reinforced walls are designed to withstand impacts and pressure. The steel dome helps accommodate thermal movement and adds an additional barrier. Air treatment equipment can filter and vent the space between the structures under controlled conditions during abnormal events.

Several engineering decisions drive how heavy a dome must be: material thickness, curvature, how ventilation components are integrated, and the reinforcement approach. More mass can support higher pressure resistance, but it also requires larger cranes and longer installation windows. Lighter domes keep the build more agile, but they require careful demonstration of safety margins.

What to watch next at Lufeng and beyond

The dome lift is a milestone rather than the end of the project. Major tasks remain: installing internal systems, completing piping and cabling, running extensive tests, and loading fuel. Grid connection trials typically come months later, followed by a prolonged series of power‑ascension checks to confirm every system performs as designed across operating conditions.

In the coming years, several indicators are likely to draw close attention:

• the actual start‑up date of Lufeng’s Hualong units compared with the 2028 target
• the time gap between dome installation and first fuel loading
• whether the CAP1000 reactors gain momentum faster now that some have approval
• how Chinese export pitches reference the Lufeng construction record as a selling point

For energy specialists and policymakers, Lufeng provides a live testbed for how standardisation, heavy‑lift practice and digital guidance can reshape nuclear construction. For those living nearby, the concerns are more immediate: secure local employment, cleaner air compared with coal, and day‑to‑day life alongside one of the most complex machines people have built.

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