Team:XMU-China/Description
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This year, XMU-China pays heed to coastal areas of China. Here, nuclear power, as a genre of clean energy, gathers solid pace. There are about 60 nuclear power units approved and operated in China with a capacity of 70.77 million kilowatts per year, the scale of which ranks the second around the world. Seawater plays an important role as an accessible heat exchanging medium at the coastal nuclear power plants. Large amounts of seawater are introduced into the cooling systems of the nuclear power plants to exchange heat, which are then discharged back into the sea. As is known, there are various organisms in the ocean. So, could these marine organisms in the seawater affect the cooling system of nuclear power plants? For this reason, we conducted an online survey.
It’s found that eutrophication of the Great Lakes due to the invasion of zebra mussels led to a frenzy outbreak of Cladophora algae in the area in 2007, causing the shutdown of the adjacent nuclear power plant named Jame A FitzPatrick three times in two months due to the clogging of filters in cooling water system, and the shutdown brought about a loss of over $2 million per day. This situation also occurred in the other nuclear and coal-fired power plants near the Great Lakes. Besides, these power plants also face problems of mussels like M. edulis who would conquer the sluices, the fences, the intake pipes, and even the tubes of condensers, also leading to the blockage and even the shutdown. Thus, we turned our attention to mussels and algae.
To learn more about the impact of mussels and algae on nuclear power plants, we interviewed the staff of Ningde Nuclear Power Plant in Fujian Province and Great Bay Nuclear Power Plant in Guangdong Province online. Using seawater as cooling water may provoke great issues, the correlative engineers told us. Firstly, the attachment and bloom of marine organisms like algae and mussels usually happen in the area of water inlets, intake pipes and the pump room, which would reduce the influx, causing deficiency of cooling water and then endangering the operating safety. Secondly, sea creatures may clog or stain the heat exchanging tubes of the condensers, which would have vital influences on the operating efficiency and the security of the power units. According to experience, there are various kinds of disaster-causing substances affecting the operation of the units, such as marine garbage, water plants, algae, jellyfishes, fishes and shrimps with floating capacity, etc.
When it comes to the mussels, the concrete impacts in disparate plants are rather different. The coarse grilles in the Great Bay Nuclear Power Plant would be thoroughly cleaned every a month and a half, scraping off the fouling, smoothing the surface, and finally polishing. And we can see from Fig.1, there are a variety of marine life wrapping in the coarse grille. While the nuclear power plant in Fujian has a longer cleaning cycle for coarse grilles. Consequently, the powerful enclosing capacity of mussels resulting in negative effects on nuclear power plants both at home and abroad is fully recognized.
Fig. 1. The employees in the power plant are dealing with the wrappings on the coarse grille.
After interviews, we plowed through papers about P. globosa, a kind of algae generating red tides. P. globosa would form colonies with a diameter of 3 cm or more when it booms, which would be the obstacles of the seawater importing to the power plants. There was an outbreak of P. globosa in the Beibu Gulf in Guangxi Province, China, at the end of 2014, which elicited a severe congestion of cooling water system at the Fangchenggang Nuclear Power Plant by the Beibu Gulf. The blockage of nuclear power plants aroused by M. edulis and P. globosa is not only reported in Guangxi, but also in the other regions of China.
In conclusion, we confirm the main direction of this year, to solve the threat of M. edulis and P. globosa to the cooling water system of the coastal nuclear power plants.
Nuclear energy is the most promising energy sources in the world nowadays. The nuclear power plants are often built in the coastal areas and the seawater is applied for heat exchanging, but the clogging issue of marine organisms in the nuclear power plants has long plagued the industry.
Our team is working on constructing a strain of engineering bacteria that can provide prevention and emergency treatment for the blockage of M. edulis and P. globosa in the nuclear power plants. The name of our project, SALVAGE, is an acronym for Scientifically and Ably Leverage Vibrio natriegens to Alleviate the problem of P. globosa and M. edulis. By the utilization of tiny bacteria, we hope to assist in guarding and even improving the safety of nuclear power plants further.
