Management of Commercially Generated Radioactive Waste - U.S. ...

4.52
4.4.1.1 Water Basin Storage of Unpackaged Spent Fuel (Example Method)
The storage of spent power reactor fuel in water basins is an established technology
that has been used successfully for over 20 years. Water basin storage has been employed
at government-owned reactors and commercial light water reactors, fuel storage basins, and
a fuel reprocessing plant. The water basin storage of unpackaged spent fuel at independent
spent fuel storage facilities and at stand-alone at-reactor basin facilities is discussed
in more detail in separate environmental impact statements (DOE/EIS-0015 1980 and NUREG-0575
1979). Water basin storage at independent spent fuel storage facilities was also examined
in detail in DOE/ET-0028.
Spent fuel elements arrive at independent storage facilities in shipping casks. The
elements are removed from the casks and are placed in storage baskets (containers) that are
designed to separate the fuel assemblies sufficiently to assure criticality safety. The
baskets are then moved to pool storage positions.
During water basin storage, the pool water serves both as a radiation shield and a heat
transfer medium to remove the radionuclide decay heat. This heat is then dissipated to the
atmosphere via a cooling tower by means of a secondary (and separate) recirculating cooling
system. The water quality in the pool is maintained by filtration and ion exchange.
Two independent water basin storage facilities for unpackaged spent fuel are described
in DOE/ET-0028 (Section 5.7). One facility stores LWR fuel assemblies containing 3000 MTHM
(metric tons of heavy metal) in six pools (each with a storage capacity of 500 MTHM) and has
the capability to receive and/or ship spent fuel at a rate of 1000 MTHM/yr. The other
facility is similar but is modified to receive spent fuel'at a higher rate and route it to
an adjacent fuel packaging facility. This modified facility has the capacity to receive
spent fuel at a rate of 2000 MTHM/yr and to store spent fuel containing 3050 MTHM. Other
sizes are considered in DOE/EIS-0015.
Radionuclide emissions during operation of such facilities were estimated for receiving
and shipping operations and for the storage condition. Table 4.4.1 contains these esti-
mates. These radionuclide emissions occur via the gaseous and airborne release route; no
aqueous releases containing radionuclides are expected.
4.4.1.2 Water Basin Storage of Packaged Spent Fuel
The water basin storage of packaged spent fuel is similar to that for unpackaged fuel
except that the fuel elements are placed into stainless steel canisters before storage.
Packaging of intact spent fuel was discussed in Section 4.3.1.1. These canisters provide
additional fuel protection, radionuclide containment barriers, and contamination control.
The facility for water basin storage of packaged spent fuel (see DOE/ET-0028, Sec-
tion 5.7.5) is somewhat different from that for storage of unpackaged fuel. Each packaged
fuel pool is designed to store spent fuel containing 2000 MTHM. The facility is designed
for modular expansion to a total of ten such pools for a storage capacity of 20,000 MT.