DEPENDENCEY TO INDEPENDENCY OF NUCLEAR POWER INDUSTRY IN INDIA by Bimal Dey

Down the memory lane:

I worked for Commissioning, first criticality and commercial operation of nuclear power stations and various related assignments for more than 37 years. I would like to share some of my observations, temporary setbacks and slowdown in Nuclear Power industry following   Embargo imposed on India soon after 1^st Nuclear tests carried out on 18.5.1974 under code name SMILLING BUDDHA in POKHRAN Test Range in Rajasthan.

I was then working in Rajasthan Atomic Power Station (RAPP) at a place called Rawatbhata about 60 KMs from city Kota, on the bank of Ranapratab Sagar Dam built on Chambal River.

The technology used for this plant was based on Pressurised Heavy Water Reactor (PHWR) for the first time in India and based on Canadian design called CANDU type  chosen by Dr. Homi J Bhabha himself among USA based Boiling Water Reactor Technology.   BW reactors need enriched Uranium whereas natural uranium is used for PHWR.  The plant was being constructed at RAPP under Canada – India agreement ( COLOMBO PLAN 1956).  Canadian engineers, operators along with Indian counter parts were working together. Most of the equipment including initial load of Fuel ( Uranium) and Heavy Water (D2O) were supplied by Canada. 3 more similar units (RAPP-2. MAPP 1&2) were under construction.

Construction and commissioning jobs were completed and RAPS unit #1 was achieved First Criticality in 1.8.1972 and regular power operation was started from 30.11.1972.

HEAVY WATER (Deuterium Oxide)

Heavy water ( D2​0 ) also called deuterium oxide, composed of deuterium, the hydrogen isotope with a mass double that of ordinary hydrogen and oxygen. Its looks same like Ordinary Water (H2O) we used.  Its physical and chemical properties are all mostly same except few but greatly differ in nuclear properties.

Heavy water is used as a Moderator in PHWR to slows down neutrons effectively with low probability of absorption of neutrons which is essential to continue fission process to generate heat. D2O is also used as heat transfer media (PHT) to Carrey heat from Reactor to Steam Generators to produce steam to roll the Turbine- Generator (TG) to produce electricity ( similar to Thermal Power Stations).

Each Reactor required 200 Tons of D2O, 130 Tons in Moderator system and 70 Tones in PHT sysem to start with. Moderator system operate be at low pressure (7KGs/cm2) and low temperature ( 130 deg C) and PHT system at high pressure ( 85 KG/CM2) and high temperature (250 deg C).

There are some amount of D2O leak particularly from PHT system during unit operation. The leaked D2O is collected by Ventilation systems inside Reactor Building and upgraded by Upgrading towers to reactor grade D2O. Make up on regular basis, to keep same inventory in Moderator and PHT systems is required.  Thus there are need for adequate stock of D2O.

EMBARGO FOLLOWING 1^ST NUCLEAR TEST IN 18^th May 1974.

During this period in 1974, there was only one PHWR type Reactor in operation (RAPS unit #1). Rest unit #2 of Rajasthan (RAPPS 2) and 2 similar units at MAPS ( Madras Atomic Power Station), Kalpakkam, TN were in advance stages of construction in collaboration with Canada. Soon after Embargo nuclear cooperation with Canada as well all over the world was suspended including supply of D2O and equipment. During that time D2O was not produced in India to the required quantities and was depending upon supply from Canada for continuous operation of RAPS #1. Also construction activities slowed down significantly.

With no supply of Heavy Water from Canada operation of the RAPS #1 was not possible.

There came USSR. Without considering international embargo, requirement of most of D2O were supplied by USSR in batches. I was fortunate to be associated to bring many consignments of Russian Heavy Water from Palam airport in Delhi, offload from Russian aircraft, load on dedicated trucks and transported to RAPS plant site escrowed by security agencies in convoy mode.  Due to this help, we could keep operating the RAPS unit #1 for many years.

Simultaneously in DAE/RAPP special dedicated group was form to help in developing various industries, suppliers to design, manufacturing of equipment, and transportation by road. Construction activities were picked up in all the remaining 3 units.  Production of Heavy Water was augmented by construction of Heavy Water plants at many locations including one in RAPP.

Of course the embargo cost about 8 to 10 years delay but India came out stronger in Nuclear technology, manufacturing and supply of various heavy equipment and in construction activities.

Since then India is self-sufficient in construction of nuclear power plants. India haspresently 23 operating Reactors and 9 more under construction at various location.  Various design deficiencies were identified and engineering changes (ECN) were incorporated where ever needed. This resulted in reliable and long continuous operation of all the operating units. Indian PHWRs are now one of the best operating reactors among all the operating nuclear power stations around the world.

We are now producing enough D2O required for all operating reactors and exporting to various countries too.

The above are few of the many initiative taken by India/ DAE/ NPCIL to come out from DEPENDENCEY TO INDEPENDENCEY OF NUCLEAR INDUSTRY IN INDIA .

About Author

Former Associate Chief Engineer (Operation), Member Secretary of AERB constituted Safety Committee (NKSC) and ex. Consultant to 500 MWe Prototype Fast Breeder Reactor being constructed at Kalpakkam, TN.