By Sampath Kumar
BBC correspondent in Kalpakkam
The authorities in India's atomic energy department have said a leakage at a nuclear plant earlier this year has not hurt either the local people or the environment.
Six people were exposed to radiation in the incident which led to agitation by the workers and temporary closure of the plant.
The leakage at a nuclear reprocessing plant at Kalpakkam, 50 kilometres (30 miles) from the southern city of Madras, took place in January, but only came to light in July.
The accident went largely unreported until late last month when the employees' union raised it.
Environmentalists say the incident raises serious questions about the safety of workers and the people living in the area.
The director of the plant, S Basu, told the BBC there had been a "minor leak" in the isolation valve separating a low-level radiation tank, and a high level one.
He said six employees were exposed to radiation doses higher than the total exposure in a normal year.
The plant was shut down after the leak
But he said all six people were medically examined and found to have had no ill-effects.
Mr Basu said they had now been transferred to "zero-radiation" areas and the incident was being investigated.
Plant officials say it will reopen only when the safety authorities give it necessary clearance to do so.
The employees and their trade union refused to talk about the incident.
But a letter from the employees' association to the management soon after the accident said the leakage could have been avoided had a system to monitor radioactivity been in place.
Environmentalists point to an earlier incident in March 1999 when large quantities of radioactive heavy water leaked during a test at the plant.
Seven employees received more than normal doses of radiation then.
A study commissioned by the Nuclear Power Corporation of India concluded that people living in the area were safe.
The study revealed that only four out of 5,500 people interviewed for the exercise were suffering from cancer.
Environmentalists dispute the finding. They say the number of cancer patients in the area is much higher.
Dr Pugazhendhi, a medical practitioner in Kalpakkam, says there are several clusters of cancer patients in the township.
He says in the central waste management department alone, four employees have died of cancer.
A 24-year-old temporary worker died of colon cancer which, according to doctors, is unusual for patients of such a young age.
Dr Pugazhendhi says there should be a thorough study of the impact of radiation on the local environment.