HKNIC - Spent Fuel and Nuclear Waste at Daya Bay

Spent Fuel and Nuclear Waste at Daya Bay
Spent Nuclear Fuel
The nuclear fuel that has been expended in the reactor during the fission process is known as spent fuel. Spent fuel assemblies are removed from the reactor during refuelling and held underwater in a fuel storage pool in the fuel building.

Daya Bay produces about 50 tonnes of spent nuclear fuel each year and the station has the capacity to store for at least 10 years' worth of spent nuclear fuel. Spent fuel is not classified as a waste since China's policy is to reprocess the spent fuel to extract useful constituents, which represent the bulk of the material, for further use.
Intermediate/Low Level Radioactive Solid Waste
The operation of a nuclear power station inevitably produces a certain quantity of radioactive waste. In line with international practice, Daya Bay confines the majority of this waste, to prevent it from coming into contact with the environment.

Specifically, the purification system for the primary circuit of the power station collects radioactive substances as sludge, resin and in filter cartridges. These substances are classified as Intermediate Level Waste and at Daya Bay are solidified and packed in concrete drums each which are 1.4 metre in diameter and 1.3 metre in height, with a total volume of 2 cubic metres and weighing about 5 tonnes. There are several drum thicknesses, from 15 centimetres to 40 centimetres, designed for waste with different degrees of radioactivity.

Certain activities at Daya Bay involve exposure to radiation, producing radioactive waste such as used tools and protective clothing. This type of waste is classified as Low Level Waste and is packed in metal drums. The metal drum measures about 0.7m in diameter and 1m in height, with a total volume of 0.4 cubic metre. A drum with a smaller capacity of 0.2 cubic metre is also used.

Daya Bay produces less than 150 cubic metres per year of this waste, including packaging, enough to fit into only three standard 40 foot containers. This waste is about a thousand times less than the coal ash that would be produced by a conventional coal fired power station supplying the same amount of power. It is kept within the power station in a dedicated storage building before being delivered to an external repository for disposal. [ Managing Nuclear Waste ]

Image Credit : DNMC

[ Solid Radioactive Waste ]