Advanced heavy-water reactor
AHWR-300 | |
---|---|
Generation | |
Fuel state | Solid |
Neutron energy spectrum | Thermal |
Primary control method | control rods |
Primary moderator | Heavy water |
Primary coolant | Light water |
Reactor usage | |
Primary use | Generation of electricity |
Power (thermal) | 920 MWth |
Power (electric) | 304 MWe |
The advanced heavy-water reactor (AHWR) or AHWR-300 is the latest Indian design for a next-generation nuclear reactor that burns thorium in its fuel core. It is slated to form the third stage in India's three-stage fuel-cycle plan.[1] This phase of the fuel cycle plan was supposed to be built starting with a 300 MWe prototype in 2016.[2]
Background
Bhabha Atomic Research Centre (BARC) set up a large infrastructure to facilitate the design and development of these advanced heavy water reactors. Things to be included range from materials technologies, critical components, reactor physics, and safety analysis.[4] Several facilities have been set up to experiment with these reactors. The AHWR is a pressure tube type of heavy water reactor. The Government of India, Department of Atomic Energy (DAE), is fully funding the future development, the current development, and the design of the advanced heavy water reactor. The new version of advanced heavy water reactors will be equipped with more general safety requirements. India is the base for these reactors due to India's large thorium reserves; therefore, it is more geared for continual use and operation of the AHWR.[5]
Motivation
Thorium is three times more abundant in the Earth's crust than uranium, though less abundant in terms of economically viable to extract proven reserves, with India holding the largest proven reserves of any country.
U or chemically separated for use in a separate "burner" reactor.
Design
The proposed design of the AHWR is that of a heavy-water-moderated
The overall design of the AHWR is to utilize large amounts of thorium and the
The reactor design incorporates advanced technologies, together with several proven positive features of Indian
The reactor physics design is tuned to maximise the use of thorium based fuel, by achieving a slightly negative
Some Distinctive Features of AHWR
- Elimination of high-pressure heavy water coolant resulting in reduction of heavy water leakage losses, and eliminating heavy water recovery system.
- Recovery of heat generated in the moderator for feed water heating.
- Elimination of major components and equipment such as primary coolant pumps and drive motors, associated control and power supply equipment and corresponding saving of electrical power required to run these pumps.
- Shop assembled coolant channels, with features to enable quick replacement of pressure tube alone, without affecting other installed channel components.
- Replacement of steam generators by simpler steam drums.
- Higher steam pressure than in PHWRs.
- Production of 500 m3/day of demineralised water in Multi Effect Desalination Plant by using steam from LP Turbine.
- Hundred year design life of the reactor.
- A design objective of requiring no exclusion zone on account of its advanced safety features.[8]
Fuel cycle
The AHWR at standard is set to be a closed
The fuel for AHWR would be manufactured by the
Future plans
The Indian Government announced in 2013 it would build an AHWR of 300 MWe with its location to be decided.[9] As of 2017, the design was in the final stages of validation.[10]
Safety innovation
Past nuclear meltdowns such as Chernobyl and Fukushima have made the improvement of construction and maintenance of facilities to be crucial. These accidents were with the involvement of uranium-235 reactors and the poor structures of the facilities they were in. Since then, International Atomic nuclear Association has stepped up protocols in nuclear facilities in order to prevent these accidents from occurring again. One of the top security measures for a meltdown is containment of radioactivity from escaping the reactor. The Defence in Depth is a method used in nuclear facilities to acquire the most effective practice of radioactive containment. The AWHR has acquired the Defense in Depth process which is used in reactors adopting provisions and required equipment in order to retain the radioactivity within the core.
The Defense in Depth method establishes procedures that must be followed in order to reduce human error incidents and machine malfunctions.[4] The procedures are the following:
- Level 1: Prevention of abnormal operation and failure
- Level 2: Control of abnormal operation and detection of failure
- Level 3: Control of accidents within the design basis
- Level 4: Control of severe plant conditions, including prevention of accident progression and mitigation of consequences of severe accidents
- Level 5: Mitigation of radiological consequences of significant release of radioactive materials.
The AWHR is an innovation in renewable energy safety as it will limit the use of fissile uranium-235 to breeding fissile uranium-233 from fertile thorium-232. The extraction of nuclear energy from the 90th element thorium is said to have more energy than the world's oil, coal, and uranium combined. The AHWR has safety features that distinguish it from conventional lightwater nuclear reactors. Some of these features consist of: strong safety systems, reduction of heat from core through a built in cooling system, multiple shutdown systems and a fail-safe procedure that consist of a poison that shuts down the system in the case of a technical failure (FBR).[4] The potential threat scientists try to avoid in reactors is the buildup of heat because nuclear energy escalates when it reacts with high temperatures, high pressures and chemical reactions. The AHWR has features that helps reduce the probability of this occurrence through: negative reactivity coefficients, low power density, low excess reactivity in the core and proper selection of material attributes built in.[11]
Technical specifications
Specifications | AHWR-300[12][13][14] |
---|---|
Thermal output, MWth | 920 |
Active power, MWe | 304 |
Efficiency, net % | 33.1 |
Coolant temperature, °C: | |
core coolant inlet | 259.5 |
core coolant outlet | 285 |
Primary coolant material | Boiling light water |
Secondary coolant material | Light Water |
Moderator material | Heavy water |
Reactor operating pressure,MPa(a) | 7 |
Active core height, m | 3.5 |
Equivalent core diameter, mm | - |
Average fuel power density, MW/m3 | - |
Average core power density, MW/m3 | 10.1 |
Fuel | (Th, 233U)MOX and (Th, 239Pu)MOX |
Cladding tube material | Zircaloy-4 |
Fuel assemblies | 452 |
Number of pins in assembly | 54 |
Enrichment of reload fuel, wt % | Ring 1: (Th, 233U)MOX/3.0
Ring 2: (Th, 233U)MOX/3.75 Ring 3: (Th, 239Pu)MOX/ 4.0 (Lower half) 2.5 (Upper half) |
Fuel cycle length, Effective Full Power Days (EFPD) | 250 |
Average discharge fuel burnup, MW · day / kg | 38 |
Core averaged reactivity coefficients in operating range | |
Fuel temperature, Δk/k/°C | -2.1 x 10−5 |
Channel temperature, Δk/k/°C | +2.5x 10−5 |
Void coefficient, Δk/k / % void | -5.0 x 10−5 |
Coolant temperature, Δk/k/°C | +4.9 x 10−5 |
Control rods | Boron Carbide in SS |
Neutron absorber
|
Gadolinium nitrate solution |
Residual heat removal system | Active : Condenser
Passive : Isolation Condenser in Gravity Driven Water Pool |
Safety injection system | Passive : Emergency Core Cooling System |
See also
- Advanced CANDU reactor
- Breeder reactor
- Generation IV reactor
- Pressurised heavy-water reactor
- Thorium fuel cycle
- India's three-stage nuclear power programme
References
- ^ "Archived copy". Archived from the original on 2014-01-27. Retrieved 2014-03-31.
{{cite web}}
: CS1 maint: archived copy as title (link) - ^ "India all set to tap thorium resources". Dec 2012. Archived from the original on 2012-05-13. Retrieved 2012-05-11.
- ^ "REPROCESSING GROUP". 18 July 2014. Archived from the original on 18 July 2014. Retrieved 9 May 2023.
- ^ a b c d Advanced Heavy Water Reactor (AHWR) BARC (Bhabha Atomic Research Centre) (India) (PDF) (Report). International Atomic Energy Agency. 2013. Archived from the original (PDF) on 19 April 2014.
- ^ "India designs new atomic reactor for thorium utilisation". The Indian Express. Mumbai. 16 September 2009.
- ^ "Thorium". Archived from the original on 16 February 2013. Retrieved 9 May 2023.
- .
- ^ "DAE AHWR Report". Department of Atomic Energy. Archived from the original on 21 October 2018. Retrieved 14 May 2023.
- ^ "Establishment of Atomic Power Stations in the Country. Aug 2013". Archived from the original on 2013-09-25. Retrieved 2013-08-29.
- ^ "Fuel for India's nuclear ambitions". Nuclear Engineering International. 7 April 2017. Archived from the original on 12 April 2017. Retrieved 12 April 2017.
- .
- ^ "2013 AHWR Design Description (India) ARIS" (PDF). International Atomic Energy Agency. 11 July 2013. Archived (PDF) from the original on 2021-09-27. Retrieved 2021-03-21.
- ^ Kumar, Arvind; Srivenkatesan, R; Sinha, R K (11 July 2013). "On the Physics Design of Advanced Heavy Water Reactor (AHWR)" (PDF). Reactor Design Development Group, Bhabha Atomic Research Centre. Archived (PDF) from the original on 2021-04-11. Retrieved 2021-03-21.