On November 8, the 100t double-girder gantry crane manufactured by Henan Mine Crane for a China National Nuclear Power project successfully passed factory acceptance. During the acceptance, the project owner carried out various high-precision tests including heavy-load moving and positioning on the crane. All test results met acceptance standards, winning full recognition from the customer. 

I. Product Introduction

Special gantry cranes for nuclear power are special lifting equipment tailor made for the construction and operation of nuclear power plants. They are not just an "upgraded version" of ordinary gantry cranes. Instead, they are high standard special machinery that is designed, manufactured, tested and fully documented following strict nuclear power standards and procedures.

II. Why are the Requirements for Cranes Used in Nuclear Power Plant Construction So Stringent?

III. What Key Factors Must Be Considered Regarding the Selection and Use of Cranes in Nuclear Power Projects?

1. Lifting capacity and micro-movement precision

Nuclear power lifting operations involve auxiliary equipment weighing dozens of tons as well as main components up to thousands of tons, such as reactor pressure vessels and steam generators. For equipment selection, it is necessary to match the exact tonnage. Meanwhile, extremely high micro-movement performance and multi-speed adjustment are required, so that heavy loads can be positioned precisely to the millimeter in confined spaces.

2. Extreme environment adaptability and nuclear grade seismic design

Nuclear power plant sites often face strong winds, large temperature differences, and high humidity. Lifting machinery must deliver excellent wind resistance, anti-skid performance, corrosion resistance and temperature adaptability. Its metal structures and electrical systems shall also meet strict nuclear grade seismic standards, for example, to withstand the Safe-Shutdown Earthquake (SSE).

3. Single fault protection and redundant safety system

To completely prevent radioactive safety accidents caused by heavy-load falling, the crane shall adopt redundant braking designs such as dual brakes. If one independent component fails, the system can still hold or control the load through backup devices. It is also standard equipped with overload limiters, real time monitoring and travel limit switches.

4. Full life cycle quality assurance and compliance traceability

Nuclear power projects feature long construction cycles and stringent maintenance requirements. Equipment manufacturing and inspection must strictly comply with nuclear safety regulations and quality assurance programs such as the NQA-1 standard. From non-destructive testing of raw materials and factory-run 125% overload verification tests, to full set lifelong traceable technical documentation, maximum reliability is guaranteed for long term service.

IV. Technical Parameters

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V. Working Principle

The basic operating logic of gantry cranes for nuclear power is the same as that of general purpose gantry cranes. The gantry travels longitudinally along ground mounted main rails, while the hoist trolley moves transversely along the main girder rails. Combined with the vertical lifting movement of the hoisting mechanism, material handling can be achieved within a three dimensional rectangular working area.

For core scenarios in nuclear power projects, including outdoor operations, heavy lift hoisting, precision equipment positioning, and long term continuous operation, the equipment is specially enhanced in structural strength, running stability, positioning accuracy and safety redundancy. Special purpose models for key nuclear island areas also need to deliver reliable performance under harsh working conditions, to ensure safe and stable execution of critical tasks such as hoisting, maintenance and transportation of power station equipment.

VI. Core Structure and Specialized Design

1. Heavy load & high rigidity gantry main structure

Large tonnage nuclear power special gantry cranes mostly adopt double main beam box type steel structures for higher overall gantry rigidity. They suit outdoor large span, high wind load and continuous heavy duty operations. The standard setup uses double trolleys / main auxiliary trolleys: the main trolley handles rated heavy load lifting, while the auxiliary trolley performs auxiliary lifting, component turnover, spreader connection and other coordinated tasks.

Both main beams and legs are optimized via finite-element simulation and dynamic load analysis. They meet the demands of long term heavy duty operation at nuclear power sites featuring large span and high wheel pressure. Low deformation under heavy loads and great anti-fatigue performance are guaranteed to support decades of reliable service for nuclear power projects.

2. Design of high-redundancy safety mechanism

The hoisting mechanism adopts a dual-brake redundant design. The two brake systems are controlled independently, ensuring no load slipping or hook drifting under rated load and eliminating risks from single point failure. Key transmission components including drums, steel wire ropes, reducers and wheels are selected with nuclear power grade safety margin, delivering much higher reliability than standard models. The electrical system features redundant control circuits with dual backup for critical circuits. It supports emergency power supply and emergency lowering function. In case of sudden power loss or malfunctions, it can lower loads to position smoothly, protecting high value nuclear power equipment and on site safety.

3. High precision micro-motion stable control

The whole machine adopts servo control plus variable frequency vector speed regulation to achieve stepless micro-motion at extremely low speeds. It starts and stops smoothly without impact, meeting the millimeter-level alignment requirements for large nuclear power equipment and precision components. Equipped with an accurate anti-swing control system, it greatly suppresses load swinging and improves hoisting stability and positioning efficiency even in strong outdoor winds.

4. Special purpose design for nuclear power projects

Based on general gantry cranes, the equipment is further upgraded to meet the special environmental and safety requirements of nuclear power projects.

Wind-resistance & anti-overturning design: Outdoor gantry cranes come standard with rail clamps, wind anchoring devices, anti-wind anti-skid features and wind speed monitoring systems. They meet high grade wind-resistance requirements for nuclear power sites and prevent crane sliding and overturning in strong wind conditions.

Anti-corrosion protection design: For coastal and offshore nuclear power projects, a heavy duty anti-corrosion coating system is adopted. It withstands salt spray, high humidity and heavy rainfall to improve structural service life.

Seismic performance & structural reliability: Key nuclear power gantry cranes undergo structural verification per project seismic requirements. This guarantees structural integrity and retention of core functions under extreme conditions such as earthquakes.

Cleanliness, dust-proof & sealing protection : Cranes working around nuclear islands and precision assembly zones are fitted with sealed electrical compartments, dust-proof walkways and oil-leak-proof structures. These block dust and contaminants, meeting cleanliness and environmental standards at nuclear power sites.

Full process quality control: Nuclear grade quality standards are followed throughout design, manufacturing, welding, inspection, coating, assembly and testing. Critical welds receive 100% non-destructive testing, with full life cycle traceability.

5. Intelligent monitoring & safety operation maintenance system

Equipped with a nuclear grade safety monitoring management system. It collects and records real time key data including lifting capacity, travel distance, speed, limit positions, temperature, wind speed and brake status. It features over limit alarm, fault diagnosis, data traceability and black box recording. Remote monitoring and operationmaintenance management are supported to improve equipment safety and standardize management, meeting strict safety requirements for nuclear power projects. 

VII. Technical Advantages

VIII. Application Scenarios for Specialized Gantry Cranes for Nuclear Power

Special purpose nuclear gantry cranes are categorized based on requirements for nuclear power plant construction, hydraulic operation & maintenance, and spent nuclear fuel reprocessing, covering different project phases. Below are the main categories and their application scenarios. 

1. Super large gantry crane for nuclear power plant construction

Technical Features: Extremely high lifting capacity, normally 800 tons to over 1600 tons. It has a span of over 100 meters and large clear lifting height. It delivers outstanding wind-resistance: resisting Grade-8 winds during operation and Grade-17 typhoons when parked. It features high structural rigidity and accurate micro-positioning.

Application Scenarios: Widely used for building Generation-III and advanced nuclear power units in nuclear island and conventional island areas. It completes integral hoisting of extra large and heavy components, including steel liner modules, prefabricated parts, internal heavy equipment, reactor pressure vessels and domes. It greatly shortens construction time and reduces risks from high altitude work.

2. Gate type crane for hydraulic structures and water intake pump house

Technical Features: Mostly medium to heavy tonnage double-girder or single-girder gantry cranes. Enhanced with heavy duty anti-corrosion treatment and electrical protection for harsh outdoor conditions including high humidity and strong winds, delivering smooth operation.

Application Scenarios: Installed in nuclear power plant circulating water pump houses, seawater intakes, conventional-island drainage areas and dam gate zones. Mainly used for frequent opening/closing and cleaning of heavy hydraulic gates and trash racks, as well as installation, turning and routine maintenance of key electromechanical equipment such as large circulating water pumps and main motors inside pump houses.

3. Gantry Crane for Handling Nuclear Waste & Radioactive Containers

Technical Features: Complies with top level nuclear safety requirements, using single failure proof design. Motors, brakes and control systems have duplicate backup setups. It is equipped with anti-fall, load-limit and precise anti-offset protection functions.

Application Scenarios: Used in nuclear power plant waste storage houses, spent-fuel temporary storage areas and dry-storage sites. It safely picks up, moves horizontally, turns over and transports radioactive waste barrels and spent-fuel dry transport casks. Even in harsh extreme conditions, it prevents radioactive leaks and uncontrolled load drops.

IX. Conclusion

The crane for this project has successfully passed factory acceptance, marking another innovative achievement of Henan Mine Crane in the nuclear power sector. Building on this milestone, both sides will deepen cooperation in technological R&D and high quality intelligent manufacturing, contributing to the high quality development of the nuclear power industry.