RD&D-Programme 2004 - SKB

9.3 SKB’s transportation system – equipment and function
The transportation system was commissioned partially in 1983 and fully in 1985. Its primary
task is to transport spent nuclear fuel to Clab and radioactive waste To SFR. SKB is responsible
for the operation of the transportation system and owns the equipment in the system. The most
important components are the ship m/s Sigyn, the transport casks and containers, and the terminal
vehicles. Transportation is planned by the operations department at SKB and is carried out
in collaboration between many organizations. The contract for the operation of Sigyn is written
with Rederi AB Gotland, whose subsidiary Destination Gotland crews and operates the ship.
9.3.1 Today’s transportation system for spent nuclear fuel and
operational waste
Each year Sigyn carries an average of 20 shiploads of casks containing spent nuclear fuel
and spent core components to Clab and about ten shiploads of operational waste to SFR in
Forsmark. Waste is also shipped from Studsvik to SFR. The waste packages are transported
either in heavy casks (ATB) or in freight containers, depending on how radioactive the waste is.
Spent fuel and core components from the Oskarshamn Nuclear Power Plant are transported
locally overland to Clab in the same transport casks as from other power plants. A special waste
transport container is used for local waste transport in Forsmark to SFR.
9.3.2 Operational experience
Experience from approximately 20 years of operation shows that the transportation system is
reliable and works well and has the necessary capacity for the planned shipments.
The quantities of spent fuel that are transported annually to Clab from the nuclear power plants
have stabilized in recent years at around 230 tonnes, which is equivalent to about 75 transport
casks per year. The number of waste shipments from all the nuclear power plants to SFR has
decreased, and the trend continues downward.
Sigyn
The ship, which was commissioned in 1982, has undergone extensive modernizations and modifications
over the years. Besides normal maintenance, the following changes have been made:
switch to low-sulphur oil, replacement of heating system, replacement of monitoring equipment
for hold and engine room, new fire extinguishing and monitoring system, double hull for fuel
tanks, and installation of catalytic converters, which has reduced nitrogen oxide emissions by
over 80 percent.
Inspections of hull and tanks are performed regularly. In a thorough going-over by experts
from Chalmers University of Technology in 1999, it was found that the ship is in good shape
and should be able to be used at least until 2010. The navigation equipment with electronic sea
charts and the recently replaced radar system are modern and of high standard.
The harbours at the nuclear power plants visited by the ship are tailored to the ship and have
good mooring arrangements. Ringhals’s entrance channel and harbour basin were dredged in
2002, which has led to improved manoeuvring conditions.
There are standard procedures for reporting incidents and nonconformances to SKB and the
shipping line. Only a few incidents involving material damage have been reported, and no
personal injuries.
RD&D-Programme 2004 105