Sellafield launches trial waste treatment for technetium 99

Publish date: October 10, 2003

Written by: Hanne Bakke

British Nuclear Fuels, or BNFL, the operator of the infamous Sellafield nuclear facility in the United Kingdom, has announced that it will launch a full-scale trial treatment of liquid radioactive waste that Bellona hopes will reduce the plant's radioactive technetium 99 discharges into the sea by 90 percent or more. Bellona, which has long pressured Sellafield to reduce these discharges, applauds this effort.

The dumping of technetium 99, or Tc-99, from Sellafield’s nuclear reprocessing plant has caused alarm and outrage among environmentalists in Norway. The discharges in recent years have led to a dramatic increase of Tc-99 among Norwegian coastal sea products such as lobster and seaweed. Tc-99 has also been measured in the Barents Sea as far north as the Arctic island of Spitsbergen.

The Bellona Foundation has been steadily applying pressure on British nuclear authorities to test a treatment method that separates Tc-99 from Sellafield’s old liquid waste using a chemical called tetraphenylphosphonium bromide, or TPP.

Sellafield’s liquid radioactive waste is stored in an onshore holding tank. Until this spring, the contents of the tank—which were cleansed of most toxic subtances but Tc-99—were being slowly dumped by portions into the Irish Sea three times a year, with the goal of emptying the tank completely by 2007.

Discharge Moratorium Agreement Reached in June
On April 21st this year, Bellona and another Norwegian NGO, Lofoten mot Sellafield, acting in cooperation with BNFL, arranged a conference at Sellafield.

At the conference, Bellona concluded that it would be feasible to halt the Tc-99 discharges for one year without violating the existing British regulations that set schedules and levels of annual Tc-99 discharges from Sellafield, buying time to complete testing of the new liquid radioactive waste treatment facility.

Norway’s Environmental Minister Børge Brende followed up this initiative during an official meeting with British authorities in May and brought more pressure to bear on British Environmental Minister Elliot Morley at a meeting of OSPAR—also known as the Convention for the Protection of the Marine Environment of the North-East Atlantic—in Bremen in late June.

On June 20th, Britain’s Department for the Environment Food and Rural Affairs appealed for a voluntary temporary halt to the Tc-99 dischargs. British authorities did not accept appeal, but BNFL promisd promised that it would start trial treatment of the liquid radioactive waste using the TPP method in October. Thursday’s announcement by BNFL demonstrates it is keeping its word.

TPP treatment
BNFL has conducted laboratory-scale testing of the so-called "TPP process." The treatment method consists of adding TPP to the liquid waste and then filtering the water out. The chemicals in the water will then be mixed into concrete and stored as medium-level solid radioactive waste in an intermediate onshore storage site before the waste is transferred to a final repository.

In total, there are over 230 TBq of Tc-99 currently stored in Sellafield’s notorious tank. During the TPP treatment trial period, which is now under way at Sellafield’s Enhanced Actinide Removal Plant, or EARP, a total of 240 cubic metres of liquid waste containing 32 TBq of Tc-99, will be cleaned in nine batches. The volume of each batch will be 27 cubic metres, containing 3.6 TBq of Tc-99.

Bellona’s Demand
The trial treatment has been agreed to be carried out in full compliance with Bellona’s demands. The laboratory-scale testing of the TPP method has resulted in the liquid radioactive waste being cleansed of 90 to 95 percent of Tc-99. Full test results are expected. Bellona will be informed of resuls as soon as they are available.

Bellona does not know at this stage what amount of radioactivity will be discharged during the upcoming eight weeks of trials, but we are optimistic that the results will be close to a 90 percent of purification rate.

This means that the discharges during the test period will be around 3 TBq—instead of the usual 30 TBq. Bellona, at present, has no knowledge of other, more effective purification technologies, and accepts that some radioactivity will still be discharged into the sea. Bellona will, however, continue to work with BNFL to study the problem.

After the trial results have been evaluated and the technology has been officially adopted by BNFL it will be clear that the concern and the British authorities are indeed set to treating the rest of the waste in the tank. It is Bellona’s hope that this will also be an unequivocal sign that BNFL and the British authorities have fully committed themselves to abandoning completely the practice of dumping this toxic substance into the sea.