Spinline™ enables utilities to improve the safety and availability of their nuclear power plants Engineering services

Spinline™ technology

spinlineSpinline™ is a modular and digital solution dedicated to developing and/or upgrading safety I&C used in nuclear reactors.
Spinline™ is specifically designed to implement any Class 1E and category A IEC-61226 safety I&C functions, at a level of qualification and certification where conventional Distributed Control System (DCS) or Programmable Logic Controllers (PLC) cannot be used.
Spinline™ can be used in any Safety system such as reactor Protection System (RPS) and Neutron Instrumentation system (NIS), in new nuclear power plants and for modernisation of existing safety I&C systems in established plant.

  • Safe operation and unproblematic maintenance due to modular, scalable and flexible design
  • Improved availability through self testing and automated periodic testing;
  • Deterministic behaviour, fail-safe and fault tolerant features, functional diversity, physical and functional separation are the main features of Spinline™ to comply with international nuclear standards;
  • State-of-the-art performance on a long term basis thanks to Rolls-Royce ability to provide long term support for plant life.

Reactor protection system

Reactor protectionWhen it comes to safety in a nuclear power plant, the Reactor Protection System (RPS) is the most important Instrumentation and Control system.

Underpinned by our patented and world-leading Spinline™ technology, the Rolls-Royce Spinline™ RPS gathers the functionalities of the Reactor Trip system as well as the ESFAS Engineering safety features actuation system. It monitors vital reactor operation parameters and in case of emergency automatically shutdown the reactor and determine the corrective actions to be taken.

All the circuits involved in correcting dangerous situations are activated by the Spinline™ RPS including: emergency shutdown of the reactor core (which interrupts the nuclear fission reaction by dropping rods into the reactor core), safety injection, start-up of the emergency feed water, steam line and feed water line isolation, containment spraying and isolation.

Rolls-Royce Reactor Protection System uses Spinline™ technology.


Because safety is so important in a nuclear environment the Rolls-Royce Reactor Protection System follows the criteria outlined in international standards and recommendations, including:

  • Single failure criterion;
  • Test during full power operation;
  • Protection against common cause failure;
  • Continuous monitoring to prevent safety actions from being bypassed and hence prohibited actions from being triggered;
  • Keeping the system safe in the event of a failure;
  • Execution of all protection actions at the right time;
  • Possibility of triggering the emergency shutdown and the safety functions manually from the control room.

Neutron Instrumentation System (NIS)

neutronThe Neutron Instrumentation System (NIS) is a major safety system for Control and Instrumentation of a nuclear reactor. The Rolls Royce NIS allows for monitoring of instantaneous nuclear power, power fluctuations, and radial/axial power distribution in the reactor using measurement of the reactor neutron flux via neutron detectors.

Rolls Royce provide a complete system which includes: source, intermediate and power detectors, conditioning and processing electronics, actuators, test and diagnostic system, and ergonomic man-machine interface.

40 years of experience (i.e. 1900 reactor years of successful operations) spanning approximately 100 nuclear reactors, has made Rolls-Royce the foremost reference for Digital Nuclear Instrumentation Systems worldwide.


  • Compliant with existing interfaces or any types of architecture within the DCS through the modular SpinlineTM technology;
  • Pioneering design aimed at the highest level of safety and ease of use;
  • Safer and reliable operation through ergonomic man-machine interface and automatic tests;
  • Simplifies maintenance due to the unique feature of our electronics which prevent the use of a preamplifier in the containment.

Diesel sequencing system

The Diesel Sequencing System provides the logic to start the diesel generator set and load the safeguard actions according to pre-established time sequences in the event of loss and subsequent restoration of Offsite Power. It operates together with the Reactor Protection System.

The Rolls-Royce Diesel Sequencing System is 1E qualified and meets international nuclear standards.

When it receives the information about voltage loss, the Rolls-Royce Diesel Sequencing System starts the following time sequences:

  • A command is sent to start up the diesel engine
  • When the diesel is ready, the system automatically switches from the mains to the diesel engine
  • The power loads are shed
  • The power loads are reloaded in a predefined order

Product details

  • Increased safety performance delivered by Rolls-Royce patented SpinlineTM technology.
  • Reduction in spare parts inventory costs through the use of standard Spinline components, as in Nuclear Instrumentation or Reactor Protection Systems, etc.
  • Improved availability due to integrated continuity tests for relay coils, ensuring that commands are carried out properly.
  • Suitable for any types of nuclear power plant, such as PWR, VVER, BWR or PHWR A command is sent to start up the diesel engine

Hardwired systems

Digital technology has now replaced Non-Programmed (Hardwired) in the majority of new and modernized Nuclear Power Plants to implement the main protection systems, thanks to its capacity to handle the growing number of parameters to process.
Nevertheless, Non-programmed systems also have numerous benefits, notably they are easier to qualify, not subject to Common Cause Failure (CCF) and possibly more resistant in post-accidental situations.
Rolls-Royce has the experience in the design and implementation of Hardwired systems for the highest safety systems (cat. A / 1E). Before the design of the Spinline™ digital platform, Rolls-Royce has implemented its hardwired systems (RPS or NIS functions) on all the French NPPs.
Rolls-Royce masters several types of Non-Programmed technologies (Analog, Failsafe Dynamic Logic and Hardwired) to implement a variety of safety systems:

  • Diverse systems in Nuclear Power Plants (as backup of the main Digital protection system)
  • The main protection system for research reactors
  • Specific Post-Accident systems as recommended post-Fukushima
  • Replacement of existing Hardwired systems with modernized Non-Programmed technology