Schacht Asse II - Inventory

Inventory

Asse II is licensed for the storage of intermediate radioactive waste (LILW-LL, Long lived) and low level waste (LILW-SL, Short lived), defined as waste without significant heat generation. After public speculation about the presence of radioactive high level waste in the pit all material was once again reviewed in August 2008:

1) 125,787 drums of low level radioactive waste stored from 1967 to 1978 in various chambers at 750 meters depth. The containers are mostly drums with volumes from 100 to 400 liters or concrete vessels. The declared total activity at the time of the respective storage amounted to 1.8·1015 Bq. Around 50% of the containers came from the nuclear reprocessing plant of the former Forschungszentrum Karlsruhe, 20% from nuclear power plants and 10% from the former Jülich Research Centre. The containers typically included mixed- and laboratory waste, rubble, scrap, filter residues and combustion residues. Liquids such as evaporator concentrates, sludges, oils, resins and solvents had to be bound as solids. According to some former employees barrels of liquid waste were accepted in the early days of storage.

2) 1293 containers with medium-level radioactive waste stored from 1972 to 1977 in the chamber 8a on 511-meter depth. Only 200-liter roll drums were allowed with waste fixed in concrete or bitumen. The declared total activity at the time of the respective storage amounted to 2.8·1015 Bq. About 97% of the packages (and thus over 90% of the total activity inventory of Asse II) originated from the reprocessing plant in Karlsruhe. A part of the Karlsruhe drums contained waste from the reprocessing plant itself and thus produced fissile material. With storage limits of 200 grams U-235, 15 g U-233 and 15 g Pu-239 per drum. These limits were not reached, the maximum values were 24 g U-235, 5.7 g Pu-239 and less than 1 g U-233 per drum on 511-meter.

The stored radioactivity of 4.6·1015 Bq is not the only measure to evaluate, the largest part of the radiologically most effective and long-lived alpha radiation occurs in the low-level radioactive waste. Therefore, the low level active waste is of particular importance for the long-term security by creating the biggest problems. The medium-active waste contains mostly relatively short-lived radionuclides which is of minor importance to the long-term safety.