The controversy surrounding the disposal of waste at the Kudankulam Nuclear Power Plant (KNPP) in Tirunelveli district has reared its head again. The Away From Reactor (AFR) facility for storing nuclear spent fuel, which was to have come up by May 2018 under orders from the Supreme Court in 2013, is still not ready. Nuclear spent fuel (fuel that has gone through the process once) is currently being stored in the At Reactor (AR) facility which can store spent fuel generated by seven years of full power operation plus one full core load.  Kudankulam Unit 1 began operations in 2014 and Unit 2 in 2017. These two pressurised water reactors (PWR) have a capacity of 1,000 MW each.

A typical 1,000 MW plant produces nearly 27 to 37 tonnes of spent nuclear fuel per year of operations. The AR pools will soon run out of space.

The AR facility is a pool of water in which the spent nuclear fuel is stored. The fuel is typically stored in assemblies of fuel racks vertically placed and having fixed spacing. The AFR facility functions the same way, except that it will be away from the reactor.

 

The storage capacity of the proposed AFR facility is 4,328 assemblies of spent fuel. The assemblies have to be cooled for a minimum of five years in the AR pools before they can be transferred to the AFR facility. A crane will be used to transport spent fuel from the AR pools to the AFR facility.

When the government-owned Nuclear Power Corporation of India (NPCIL), under the Department of Atomic Energy, could not complete the AFR by 2018, it sought more time. In the affidavit submitted to the Supreme Court, NPCIL acknowledged that setting up the AFR facility was a challenging task “on account of no previous experience with long storage requirements of high burn-up Russian type PWR fuel.”

 

Environmental activists also approached the court seeking to shut down the nuclear plant until the AFR facility was built. But the court rejected the plea and extended the deadline for building the AFR facility to April 30, 2022. The court has also stated that no further extensions can be sought by the NPCIL.

If the AFR facility is not built on time, reactor operators might have to pack the spent fuel nuclear waste more closely together in the AR storage pools, potentially increasing the risk of loss of cooling water in the pools which could result in the nuclear fuel heating to a temperature high enough to result in a release of volatile radioactive material.

The AFR facility is going to be built on 0.35 ha of land within the existing operational reactor premises and environmentalists say that storing spent nuclear fuel at the plant in the long run poses a long-term health and environmental risk. Storing spent fuel in pools is a good temporary waste storage method for lesser amounts of waste. “As long as the pool is safe, there is no need to worry. But if due to any accident, it is damaged, there is a chance of nuclear contamination. Since the half-life of these wastes is about 1,000 years or so, it will be very difficult to separate it from the contaminated material,” says Prafulla Kumar Behera, Associate Professor, Department of Physics, IIT Madras. Half-life of a radioactive element is the time required for half of it to decay.

According to the Environment Impact Assessment report, the proposed AFR facility is only to store spent nuclear fuel waste from the currently operational Unit 1 and Unit 2 of the Kudankulam nuclear power plant. Four additional units are scheduled to be added according to the agreement signed between India and Russia. The capacity of each of these units is 1,000 MW and they are expected to be completed by 2023-24.

 

Kudankulam Units 3 and 4 are under construction at a cost of Rs 39,849 crore. Kudankulam Units 5 and 6 will be built at a cost of Rs 49,621 crore. When all of these upcoming projects are completed, Tamil Nadu will have a total installed nuclear power capacity of 6,000 MW. This will lead to a rise in nuclear waste generation.

The AFR facility only has a design life of 75 years after which alternative methods of storing the nuclear waste would have to be considered. Experts feel that a long-term solution will be a deep ground repository (DGR).

 

“A deep ground repository is a long-term solution for nuclear waste but we need to have it deep underground such that radioactive waste can be kept in isolation for a long time (more than 1,000 years for plutonium).  The spent nuclear fuel also has to be cooled to room temperatures before it can be buried underground in a DGR.” says Dr Behera. A deep ground repository must ideally be built in a place where the nuclear waste would remain undisturbed. Currently, India does not have a DGR and the Atomic Energy Regulatory Board (AERB) of India does not have in place the regulatory requirements for a DGR.

 

There are no deep ground repositories in the world. In May 2001, Finland approved a DGR in Olkiluoto, which is expected to begin operation in 2020. “Deep ground repositories have stringent siting requirements. Identifying a site with seismic stability is a challenge. USA has spent considerable amount of resources, both financial and technical, to put in place a repository at Yucca Mountains, but abandoned it as there was no public acceptance," says Prof M Sai Baba, scientist and former Director of Resources Management Group, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam.

“There is a huge effort now to reprocess nuclear waste so that risks can be reduced. One way is to separate nuclear waste into different elements according to their intensity and half-life. In India, we reprocess nuclear waste into fuel,” says Behera.

 

India follows a closed fuel cycle where nuclear waste is reprocessed but nuclear waste from Kudankulam is not being reprocessed currently. "The existing reprocessing facilities in India are designed for spent fuel from Pressurised Heavy Water Reactors, rather than light water reactors of the kind installed in Kudankulam,” says environmentalist G Sundarrajan, founder of the NGO Poovulagin Nanbargal.

 

Answering a question raised in the Rajya Sabha in 2018, Minister Jitendra Singh acknowledged that currently there is no reprocessing facility for nuclear waste produced in Kudankulam.

“The Kudankulam nuclear plant is only functioning with around 33 per cent efficiency. During the last five years, the plant had tripped 48 times. They also frequently shut down the plant due to faults and maintenance.” says Sundarrajan.

 

With no official figures made available as to how much high level nuclear waste is being generated in Kudankulam, people and environmental activists are concerned about the declining efficiency and lack of transparency of Kudankulam nuclear power plant.

All nuclear power generating countries have only interim nuclear waste facilities like

 

Storage pools – Nuclear waste stored in pools near the reactor or away from it, which serves the dual purpose of both cooling down the nuclear waste and serving also as an interim storage facility

Dry cask storage - Spent fuel that has cooled in spent fuel pool for at least one year can be encapsulated in a steel dry cask, which is welded or bolted closed when it is moved out from water. The cask is pumped with inert gas inside, and then is contained into another cask made of steel, concrete, or other radiation shielding material. Subsequently, this leak-tight and radiation-shielded dry cask can be stored either horizontally or vertically on a concrete pad

According to the World Nuclear Association, “The option of disposal of waste into space has been examined repeatedly since the 1970s. This option has not been implemented and further studies have not been performed because of the high cost and the safety aspects associated with the risk of launch failure.“

The present installed nuclear power capacity in the country comprises of 22 reactors with an installed capacity of 6,780 MW.  At present, there are nine nuclear power reactors at various stages of construction, targeted for completion by 2024-25. In addition, 12 more nuclear power reactors have been accorded administrative approval and financial sanction by the government in June 2017. Thus, 21 nuclear power reactors, with an installed capacity of 15,700 MW are under implementation, envisaged for progressive completion by 2031. The share of atomic energy in the overall electricity generation in the country was about 2.93% in 2017-18

In all of history, only two events have been designated a "Level 7", the highest in the International Nuclear Event Scale, a classification used by the International Atomic Energy Agency (IAEA) to refer to major nuclear accidents with widespread health and environmental effects. The first is Chernobyl and the second is Fukushima

A Level 7 nuclear accident involves major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended counter measures

An experiment at the Chernobyl nuclear facility’s four reactors created a sudden power surge, which in turn led to a series of blasts that blew the 1,000-tonne steel top off of the reactor. A lethal cloud of radioactive material gathered over the nearby town of Pripyat and gradually spread over to large parts of Europe. The radiation that escaped into the atmosphere was equivalent to several times that produced by the atomic bombs dropped on Hiroshima and Nagasaki and it contaminated millions of acres of forest and farmland

The explosion and subsequent meltdown of the Chernobyl nuclear plant claimed thousands of lives, caused countless birth defects and a thyroid cancer epidemic in the region. Large areas surrounding the plant may not be liveable for as much as 150 years which includes the 18-mile radius around Chernobyl

The earthquake and tsunami that hit Fukushima on March 11, 2011, caused a serious nuclear accident at the Fukushima Dai-ichi nuclear power plant. The earthquake cut off external power to the reactors and the tsunami, which reached levels more than twice as high as the plant was designed to withstand, damaged the reactor cooling systems, disabled backup diesel generators and battery power was also quickly exhausted. Overheating of fuel in the plant's reactor cores led to hydrogen explosions that severely damaged three of the reactor buildings. Fuel in three of the reactor cores melted, and radiation released from the damaged reactors contaminated a wide area surrounding the plant. Loss of power also caused the spent fuel pool to overheat and this also contributed to the contamination. The tsunami also damaged and obstructed roads, making outside access difficult