Heat only nuclear plants proposed to get rid of coal power at one third the cost

There has been proposal in China to switch from fossil fuel burners to “swimming pool” nuclear reactors.

Wang Naiyan, honorary chairman of the China Nuclear Society and a lead scientist at the China Institute of Atomic Energy, said top state leaders had responded positively to the plan to replace coal and natural gas heating plants in northern China with the reactors – small, simple nuclear heating plants with “zero meltdown risk”.

Each winter, China chokes from the half a billion tonnes of coal it uses for heating – enough to power Britain for nearly three decades.

ndustry specialists warn that the biggest challenge would be getting public support for the swimming pool reactors, which are in theory safe enough to swim in.

“We nuclear scientists may think it is absolutely safe, but most people may still refuse to have a reactor on their doorstep,” said Zhang Jige, associate professor at Shanghai Jiao Tong University’s school of nuclear science and technology.

Concerns have also been raised about how to store and handle the large amount of radioactive waste produced by the reactors. China is also making molten salt nuclear reactors. Nextbigfuture notes that there are molten salt reactor designs which could use unburned nuclear material (waste) from conventional nuclear reactors.

The central government has commissioned Xian Jiaotong University, a nuclear research base in northwestern China’s Shaanxi province, to draw up a blueprint for a demonstration plant suitable for universal use.

The plant could be built in a major city in the region, like Baotou in Inner Mongolia, where severe pollution makes it a prime testing ground. If accepted by residents and approved by environmental regulators, a demonstration project could be up and running in less than three years, Wang said.

Each of the proposed heating plants would cost about 1.3 billion to 1.4 billion yuan (US$197 million to US$212 million) to build, a fraction of the price of a commercial nuclear power plan.

How do the reactors work?
Each steel-and-concrete reactor pool measures about 10 meters in diameter and 20 meters deep, and holds up to 1,800 tonnes of water. A nuclear core is submerged in the water and can create up to 400 megawatts of heat to water to about 90 degrees Celsius for distribution through the city’s public heating network.

A single reactor can produce enough energy to heat 10 million square meters of living space within a 35km range. Two or three reactors would be enough heat a mid-sized city, though bigger metropolitan centers like Beijing would require more units.

“Together these small, simple reactors for heat generation can reach a scale many times [that of the] large, sophisticated and expensive nuclear power plants under construction or planned for electricity production,” Wang said.

Ke Guotu was chief designer of 400-megawatt Yanlong low-temp thermal nuclear reactor for central heating under China National Nuclear Corporation. Even if an earthquake or tsunami happened to the reactor, making it unable to stop, the water would take over one month to boil away. The reactor will not melt down unless the water is boiled away.

Nuclear group assistant general manager Li Xiaoming:

1. first step is the reactor demonstration demonstration project
2. Then build a 400 MW Yanlong reactor type. They expect to start construction by the end of 2018.

In 1998, Deep Pool Reactors designs (DPRs) for nuclear district heating were described in research papers.

Another paper Economic Feasability of Heat supply from simple and safe nuclear plants was by Jiafu Tian, Institute of Nuclear Energy Technology, Tsinghua University,

Use of nuclear energy as a heating source is greatly challenged by the economic factor since the nuclear heating reactors have relative small size and often the lower plant load factor. However, use of very simple reactor could be a possible way to economically supply heat. A deep pool reactor (DPR) has been designed for this purpose.

The DPR is a novel design of pool type reactor for heat only supply. The reactor core is put in a deep pool. By only putting light static water pressure on the core coolant, the DPR will be able to meet the temperature requirements of heat supply for district heating.

The feature of simplicity and safety of DPR makes a decrease of investment cost compared to other reactors for heating only purpose. According to the economical assessments, the capital investment to build DPR plant is much less than that of pressurized reactor with pressure vessels. For the DPR with 120 MW or 200 MW output, it can bear the economical comparison with usual coal-fired heating plant. Some special means taken in DPR design make an increase of the burn-up level of spent fuel and a decrease of fuel cost. The feasibility studies of DPR in some cities in China show that heating cost using nuclear energy is only one third of that by coal and only one tenth of that by nature gas.

Therefore, the DPR nuclear heating system provides an economically attractive solution to satisfy the demands of district heating without contributing to increasing greenhouse gas emissions.