A Report by Greenpeace International

Introduction
Sellafield
La Hague
Dounreay
Radiological Impact
Conclusion

INTRODUCTION

Over the last four decades discharges of radioactive substances from reprocessing facilities have played a major role in the contamination of the North West European shelf (Channel, North Sea, Irish Sea, North East Atlantic). Reprocessing is by far the largest contributor to the total radioactive discharges in the North East Atlantic and has attributed more than 97 % of the total site inputs. The discharged radioactivity from reprocessing facilities is spread throughout the whole Atlantic Ocean. It can even be detected in the Nordic Seas and South West of Greenland. Moreover since the beginning of the 1990s the liquid discharges of reprocessing facilities have significantly increased This report provides an overview of these recent trends in discharges and their impact on contamination levels in the marine environment, as well as possible consequences for human health and marine ecosystems.

SELLAFIELD

In 1993 BNFL, the operator of Sellafield, was given a new discharge authorisation, allowing increases in discharges due to the start up of its new Thermal Oxide Reprocessing Plant (THORP) and the Enhanced Actinide Removal Plant (EARP). Since the start up of EARP a backlog of stored wastes on site is again released to the sea. The activity of some isotopes, like Pu-239 and Am-241 have been reduced in the waste streams, but the same plant causes a significant increase in the release of other isotopes, particularly Sr-90 and Tc-99. It should be noted that these increases occurred while no active chemical separation took place in THORP in 1994 and only limited separation took place in 1995. The recent changes in the discharges will therefore be amplified if the throughput of THORP reaches its anticipated levels. Especially the discharges of tritium, C-14 and I-129 are expected to increase significantly when full commissioning of THORP takes place. As expected, the recent increase in the release of different isotopes now starts to have a dramatic effect on the marine environment. New research reveals that the contamination levels of biota in the vicinity of the Sellafield outlet and even on the Irish coast are already affected by these radiologically significant isotopes which now become more dominant in the Sellafield liquid discharges. Moreover the results of a recent study in the Irish Sea reveal that the laboratory values are generally much lower than the values based on field-studies. This is extremely worrying since Sellafield's Tc-99 discharges have raised more than 20-fold in the last few years. The fact that this is authorised without any detailed understanding of the environmental behaviour of this isotope is unacceptable.

Figure 1: Discharges of Tc-99 and resulting concentrations in seaweed from Balbrigan (Irish Coast)

LA HAGUE

As with Sellafield the downward trend from the late 1980s stops in the beginning of the 1990s and in fact the total activity discharged into the marine environment is rapidly increasing. The principal reason for this is the large increase in throughput of spent fuel in the reprocessing factories at La Hague (UP2 and UP3) and the lack of filtering techniques applied for some principal isotopes. The operators of the La Hague installations, COGEMA admit that tritium is not filtered at all from the liquid nor gaseous releases. It is shown that tritium contamination in the German Bight is rapidly increasing. The initial value of contamination was 1,9 Bq/l in 1980 and decreased to 1,1 Bq/l in 1992. After 1992 the amount of tritium increased rapidly and now show average contamination levels of 2,8 Bq/l, significantly higher than the 1980 value. A similar effect is observed with I-129, where a significant fraction (40%-60%) of the I-129, trapped in the spent fuel, is released to the environment. Since the beginning of the 1990s both the discharges of I-129 and the contamination of I-129 in seaweed in the Channel increase. In fact, when looking at the possibilities to remove I-129 from the waste streams, COGEMA acts in clear breach of the legal obligation contained in Paris Convention (1974) agreement and the OSPAR Convention for the Protection of the North East Atlantic (1992) to apply the best available techniques. In its Technical report No. 276 IAEA concludes that removal of I-129 from the waste to about 99% and managing the I-129 on land is practicable. I-129 is of particular concern because it has been identified as one of the isotopes most likely to cause radiation exposure to large populations. It should be noted that COGEMA does not provide any information on I-129 levels in the environment in their reports.

Figure 2: Throughput and discharges of significant isotopes.