Daya Bay shut down until control rod safety improves

Daya Bay nuclear plant in southern China has been shut down indefinitely following failure of safety tests, apparently the result of a design flaw.

Unit 1 has repeatedly failed control rod safety tests, and attempts to correct the problem by Framatome, the French builder, have only worsened the problem, according to the Financial Times. The control rods are dropped to stop the reaction at the heart of the unit. China has established a maximum allowable drop time of 2.15 seconds and seven of the 53 rods were slower on a Feb. 14, test. Framatome replaced the rods in Unit 1 in March then retested on March 21, with even poorer results. The unit has been shut down since Dec. 17, 1994, and cannot be used until it passes this test.

Unit 2 was shut down in April for routine refueling and inspection. This unit passed the test, but the rods fell slower than in previous control rod drop tests, indicating the problem is in the design and tends to worsen over time. It is now feared that Unit 2 will soon begin failing the tests.

The rods are not a danger while the reactor is shut down, but China is disturbed by the hazard. The plant has been controversial from the start. In 1986 a petition was created protesting the construction. It gathered more than 1 million signatures.

China Light and Power Co. owns 25 percent of the plant and the remainder is owned by Guangdong Nuclear Investment Co., a Chinese consortium. Daya Bay is losing revenue needed to make payments on the loans used to build the facility. It is estimated that $120 million is due on these loans in July. Banque Nationale de Paris leads the syndicate that made the loans. Efforts are under way to reschedule the payments.

The plant cost (US)$4 billion and is China`s first commercial nuclear plant. Construction began in 1986, with Unit 1 starting in February 1994 and Unit 2 starting in May 1994.

Framatome received contracts to build two more reactors at the Daya Bay plant in January 1995, but the contracts are in jeopardy. They are not binding until financing for the expansion is finalized. If the financing is not complete by July 15, the project will be reopened for bidding.