# IPHWR-220

The IPHWR-220 (Indian Pressurized Heavy Water Reactor-220) is an Indian pressurized heavy-water reactor designed by the Bhabha Atomic Research Centre. It is a Generation II reactor developed from earlier CANDU based RAPS-1 and RAPS-2 reactors built at Rawatbhata, Rajasthan. It can generate 220 MW of electricity. Currently, there are 14 units operational at various locations in India. It is sometimes referred to as a small modular reactor due to its modularization.
The IPHWR design was later expanded into 540 MW and 700 MW designs, as well as the AHWR-300 design.

## Reactor fleet

IPHWR-220 Reactor fleet :
| Power station | Location | Operation start | Status |
| MAPS-1 | Kalpakkam, Tamil Nadu | 27 January 1984 | Operational |
| MAPS-2 | Kalpakkam, Tamil Nadu | 21 March 1986 | Operational |
| NAPS-1 | Narora, Uttar Pradesh | 1 January 1991 | Operational |
| NAPS-2 | Narora, Uttar Pradesh | 1 July 1992 | Operational |
| KAPS-1 | Kakrapar, Gujarat | 6 May 1993 | Operational |
| KAPS-2 | Kakrapar, Gujarat | 1 September 1995 | Operational |
| RAPS-3 | Rawatbhata, Rajasthan | 1 June 2000 | Operational |
| RAPS-4 | Rawatbhata, Rajasthan | 23 December 2000 | Operational |
| RAPS-5 | Rawatbhata, Rajasthan | 4 February 2010 | Operational |
| RAPS-6 | Rawatbhata, Rajasthan | 31 March 2010 | Operational |
| KGS-1 | Kaiga, Karnataka | 6 November 2000 | Operational |
| KGS-2 | Kaiga, Karnataka | 6 May 2000 | Operational |
| KGS-3 | Kaiga, Karnataka | 6 May 2007 | Operational |
| KGS-4 | Kaiga, Karnataka | 27 November 2010 | Operational |

## Technical specifications

| Specifications | IPHWR-220 | IPHWR-540 | IPHWR-700 |
| Thermal output, MWth | 754.5 | 1730 | 2166 |
| Active power, MWe | 220 | 540 | 700 |
| Efficiency, net % | 27.8 | 28.08 | 29.08 |
| Coolant temperature, °C: | ? | ? | ? |
| core coolant inlet | 249 | 266 | 266 |
| core coolant outlet | 293.4 | 310 | 310 |
| Primary coolant material | Heavy Water | Heavy Water | Heavy Water |
| Secondary coolant material | Light Water | Light Water | Light Water |
| Moderator material | Heavy Water | Heavy Water | Heavy Water |
| Reactor operating pressure, kg/cm$^2$ (g) | 87 | 100 | 100 |
| Active core height, cm | 508.5 | 594 | 594 |
| Equivalent core diameter, cm | 451 | - | 638.4 |
| Average fuel power density | 9.24 KW/KgU | - | 235 MW/m$^3$ |
| Average core power density, MW/m$^3$ | 10.13 | - | 12.1 |
| Fuel | Sintered Natural UO$_2$ pellets | Sintered Natural UO$_2$ pellets | Sintered Natural UO$_2$ pellets |
| Cladding tube material | Zircaloy-2 | Zircaloy-4 | Zircaloy-4 |
| Fuel assemblies | 3672 | 5096 | 4704 fuel bundles in 392 channels |
| Number of fuel rods in assembly | 19 elements in 3 rings | 37 | 37 elements in 4 rings |
| Enrichment of reload fuel | 0.7% U-235 | 0.7% U-235 | 0.7% U-235 |
| Fuel cycle length, Months | 24 | 12 | 12 |
| Average fuel burnup, MW · day / ton | 6700 | 7500 | 7050 |
| Control rods | SS/Co | Cadmium/SS | Cadmium/SS |
| Neutron absorber | Boric Anhydride | Boron | Boron |
| Residual heat removal system | Active: Shutdown cooling system Passive: Natural circulation through steam generators | Active: Shutdown cooling system Passive: Natural circulation through steam generators and Passive Decay heat removal system | Active: Shutdown cooling system Passive: Natural circulation through steam generators and Passive Decay heat removal system |
| Safety injection system | Emergency core cooling system | Emergency core cooling system | Emergency core cooling system |