Nowadays, the most common nuclear reactors (PWRs and BWRs) rely mostly on active safety systems. Active in the sense that they involve electrical or mechanical operation on command systems (e.g., high-pressure water pumps). But the trend is to introduce more passive design features.
Passive nuclear safety is a design approach that is more or less in use in nuclear power plants. Passive safety systems are designed to accomplish safety functions without any active intervention on the part of the operator or electrical/electronic feedback to bring the reactor to a safe shutdown state in the event of a particular type of emergency (usually overheating resulting from a loss of coolant or loss of coolant flow). These systems take advantage of natural forces or phenomena such as gravity, pressure differences, or natural heat convection.
The primary design objective of the advanced passive technology is to provide greatly simplified nuclear plant designs that meet or exceed the latest regulatory requirements and safety goals while being economically competitive with other systems.
Passive safety systems include: passive safety injection, passive residual heat removal, and passive containment cooling. These systems have been designed to meet the NRC single-failure and other recent criteria.
More recently, however, new reactor designs are making more extensive use of passive safety features for a variety of purposes, for instance, for core cooling during transients, design basis accidents or even severe accidents, or for containment cooling, with the claim that passive systems are highly reliable and reduce the cost associated with the installation and maintenance of systems requiring multiple trains of equipment requiring expensive pumps, motors, and other equipment as well as redundant safety class power supplies.
References:
Nuclear and Reactor Physics:
- J. R. Lamarsh, Introduction to Nuclear Reactor Theory, 2nd ed., Addison-Wesley, Reading, MA (1983).
- J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.
- W. M. Stacey, Nuclear Reactor Physics, John Wiley & Sons, 2001, ISBN: 0- 471-39127-1.
- Glasstone, Sesonske. Nuclear Reactor Engineering: Reactor Systems Engineering, Springer; 4th edition, 1994, ISBN: 978-0412985317
- W.S.C. Williams. Nuclear and Particle Physics. Clarendon Press; 1 edition, 1991, ISBN: 978-0198520467
- G.R.Keepin. Physics of Nuclear Kinetics. Addison-Wesley Pub. Co; 1st edition, 1965
- Robert Reed Burn, Introduction to Nuclear Reactor Operation, 1988.
- U.S. Department of Energy, Nuclear Physics and Reactor Theory. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
Nuclear Safety:
- IAEA Safety Standards, Safety of Nuclear Power Plants: Design, SSR-2/1 (Rev. 1). VIENNA, 2016.
- IAEA Safety Standards, Safety of Nuclear Power Plants: Commissioning and Operation, SSR-2/2 (Rev. 1). VIENNA, 2016.
- IAEA Safety Standards, Deterministic Safety Analysis for Nuclear Power Plants, SSG-2 (Rev. 1). VIENNA, 2019.
- IAEA TECDOC SERIES, Considerations on the Application of the IAEA Safety Requirements for the Design of Nuclear Power Plants, IAEA-TECDOC-1791. VIENNA, 2016.
- Safety Reports Series, Accident Analysis for Nuclear Power Plants with Pressurized Water Reactors. ISBN 92–0–110603–3. VIENNA, 2003.
- Appendix A to 10 CFR Part 50, “General Design Criteria for Nuclear Plants.”
- NUREG-0800, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition.
- Nuclear Power Reactor Core Melt Accidents, Science and Technology Series. IRSN – Institute for Radiological Protection and Nuclear Safety. ISBN: 978-2-7598-1835-8
- ANSI ANS 51.1: Nuclear Safety Criteria for the Design of Stationary Pressurized Water Reactor Plants, 1983.
See above:
Safety Systems