RD&D-Programme 2004 - SKB

1 The nuclear waste system
The Swedish power industry has been generating electricity by means of nuclear power for
more than 30 years. Operation of the nuclear power plants gives rise to various types of radioactive
waste, called nuclear waste. The total quantities of nuclear waste that must ultimately be
disposed of are dependent on the number of nuclear reactors and their operating time. The waste
quantities influence the required capacity of the different waste facilities. The quantities do not,
however, influence the fundamental steps needed to dispose of the waste.
Swedish law regulates nuclear waste management. The legislation is very clear concerning
producer responsibility. The owners of the nuclear power plants are responsible for managing
and disposing of the nuclear waste in a safe manner. This includes decommissioning the
facilities at the end of their service life, conducting research and development on final disposal,
and studying alternative options. The owners have to pay all costs for this. An account of the
activities must be submitted to the authorities every third year. This programme for research,
development and demonstration, RD&D 2004, is such an account.
The power utilities that have nuclear power plants in Sweden are Vattenfall AB (Ringhals),
Sydkraft Kärnkraft AB (Barsebäck), OKG Aktiebolag (Oskarshamn) and Forsmarks Kraftgrupp
AB. The jointly owned company Svensk Kärnbränslehantering AB (Swedish Nuclear Fuel and
Waste Management Co, SKB) has been assigned the task of managing and disposing of the
nuclear waste in such a manner than human health and the environment are safeguarded in the
short and long term. This mission is an important part of the national environmental objective
of creating a safe radiation environment. SKB’s activities are overseen by the Swedish Nuclear
Power Inspectorate (SKI) and the Swedish Radiation Protection Authority (SSI).
1.1 Facilities for nuclear waste
The nuclear waste is divided into different categories according to the level of radioactivity
(low-, intermediate- or high-level waste) as well as according to the longevity of the activity
(short- or long-lived waste). Most of the waste from the nuclear power plants, about 85 percent
in terms of volume, is short-lived and low- and intermediate-level. It arises both during operation
of the facilities and when they are decommissioned. Operational waste consists, for
example, of spent filters, replaced components and used protective clothing, while decommissioning
waste consists of such items as scrap metal and building materials.
Other long-lived waste also arises in connection with the operation and decommissioning of the
nuclear power plants. Spent components from the reactor core or its immediate vicinity belong
to this category. The components contain long-lived radionuclides that are formed when stable
elements in, for example, steel are exposed to strong neutron bombardment from the reactor
core.
Spent nuclear fuel comprises a small fraction of the total waste volume, but contains by far
most of the total radioactivity, both short- and long-lived. The decay (disintegration) of the
radionuclides causes them to emit radiation and generate heat, so-called decay heat. Eventually,
as the short-lived substances decay, the radioactivity in the spent fuel will be dominated by the
long-lived substances. Spent nuclear fuel requires radiation shielding in conjunction with all
handling, storage and final disposal. The decay heat requires cooling to prevent the fuel from
overheating. The content of long-lived radionuclides determines the layout of a final repository.
The presence of fissionable material requires measures to prevent criticality and keep the fuel
from falling into the wrong hands.
RD&D-Programme 2004 19