THE MINISTER OF STATE FOR PERSONNEL, PUBLIC GRIEVANCES & PENSIONS AND PRIME MINISTER’S OFFICE (SHRI V. NARAYANASAMY) :
(a) Yes, Sir. Thorium plays a pivotal role in Indian Nuclear power programme. Right from
the inception of Indian nuclear power programme, work has been carried out on various aspects
of thorium utilisation-mining and extraction of thorium, fuel fabrication, irradiation in
reactors, reprocessing and refabrication. In addition, studies have been carried out regarding
use of thorium in different types of reactors.
Details of Research Programme:
(i) Thorium fuel fabrication through powder pellet route has been well established. Few
tons of fuel have been made for CIRUS and Dhruva, Pressurised Heavy Water Reactor (PHWR) and
for blanket assemblies for Fast Breeder Test Reactor (FBTR). Few pins have been fabricated
using mixed oxides of (Th-Pu) for irradiation in research reactors.
(ii) Thoria bundles are used in the initial cores of PHWR. The irradiation experience of
thoria fuel in the research reactors CIRUS and Dhruva, PHWR and test irradiations are
satisfactory.
(iii) The thoria pins of CIRUS have been reprocessed to obtain U233. The recovered U233
has been fabricated as fuel for KAMINI reactor at Kalpakkam. The Post Irradiation Examination
of one of the thoria bundle irradiated in PHWR has also been carried out for validation of
theoretical analyses.
(iv) Studies have been carried out regarding use of thorium in different types of reactors
with respect to fuel management, reactor control and fuel utilisation.
(v) A Critical Facility for Advanced Heavy Water Reactor has been commissioned in 2008
and is used for carrying out experiments to further validate the physics design features of
Advanced Heavy Water Reactor.
(vi) A small research reactor KAMINI with 30 kWth capacity which utilises nuclear fuel
based on Uranium-233 derived from irradiation of thorium, has been in operation at Indira
Gandhi Centre for Atomic Research (IGCAR), Kalpakkam.
Generation of power from Thorium:
(i) While it is true that Thorium can be used to produce nuclear energy, it should be
noted that Thorium cannot be used directly. Thorium does not contain any fissile isotope,
hence it cannot be used in a reactor alone. It can be used with added fissile material that
can be either enriched Uranium, Plutonium or Uranium-233 (obtained after irradiation of
Thorium).
(ii) Thorium absorbs the neutrons, which can more efficiently produce more Plutonium in
Fast Breeder Reactor for a faster growth. Therefore, using Thorium in the first, or an
early part of second stage of nuclear power programme will adversely affect the rate of
growth of nuclear power generation capacity in the initial periods.
(iii) Due to these reasons, large scale deployment of Thorium is to be postponed till the
later part of the second stage. Thorium is to be introduced only at an optimal point during
operation of Fast Breeder Reactors in the second stage. Thorium, for power generation is to
be used mainly in the third stage. The time taken for large scale thorium deployment is
around 3 - 4 decades after the commercial operation of Fast Breeder Reactors with short
doubling time. All efforts towards technology development and demonstration are made, so
that a mature technology is available in time. The third stage of Indian nuclear power
programme contemplates making use of Uranium-233 to fuel Uranium-233 – Thorium based
reactors, which can provide energy independence to the country for several centuries.
(iv) To accelerate thorium utilisation, BARC has designed an Advanced Heavy Water Reactor
(AHWR) to serve as a technology demonstrator. The 300 MWe reactor is specially meant for
demonstration of large scale commercial utilisation of thorium, generating nearly 70% of
its power from in-situ burn up of thorium. The design of all nuclear systems of the reactor
has been completed and associated confirmatory R&D is in a very advanced stage. Detailed
engineering is being carried out in consultancy mode.
(b) No, Sir.
(c)&(d) Thorium is a naturally occurring radioactive chemical element and it plays
a pivotal role in Indian Nuclear power programme. The Government has notified Thorium as
Prescribed Substance under the Atomic Energy Act 1962. The Government has also notified
Atomic Energy (Working of the Mines, Minerals and Handling of Prescribed Substances) Rules
1984 under which no person shall mine, mill, process and/or handle any ore mineral or other
material from which any one or more of the Prescribed Substances can be extracted, without
obtaining a license and except in accordance with the terms and conditions of such license.
