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

4.93
Six accidents were postulated for spent fuel packaging operations: three minor, two
moderate and one severe. The three minor accidents involve minor fuel-handling equipment
failures and are expected to result in no releases of radioactive material.
A dropped fuel element occurring about once per year was considered a moderate accident.
The 70-yr dose to the maximum-exposed individual from this accident was estimated to be less
than 1 x 10 -5 rem.
A worst-case fuel drop accident, in which the cladding on 20% of the fuel rods is rup-
tured, was estimated to occur once every 100 years. This severe accident is estimated to
result in less than 3 x 10 -5 rem accumulated dose to the maximum-exposed individual during
the 70 years after the accident.
4.8.1.4 Radiological Impacts from Packaged Spent Fuel Storage Accidents
If spent fuel is to be stored for extended periods before disposal, it may be
desirable to store it as packaged spent fuel. Accidents at such facilities are discussed
here. Accidents for the handling of spent fuel at a waste repository are discussed in
Section 5.5.
Representative accidents for packaged spent-fuel receiving operations were considered
to be similar to those postulated for a spent-fuel packaging facility (Section 4.8.1.3).
Four technologies were considered for the extended storage of packaged spent fuel: one
wet and three dry. A water basin concept was considered for wet storage. Dry storage was
considered in vaults, caissons and surface casks.
Nine accidents were postulated for the water basin storage of packaged fuel. Six are
the result of the loss of essential basin services and would cause no release. A strike by
a design-basis tornado or a criticality in the pool were considered to be severe accidents,
but are expected to release less radioactivity to the environment than the equivalent acci-
dents in the pool storage of unpackaged fuel discussed in Section 4.8.1.2 (a 70-yr dose to
the maximum-exposed individual of 5 x 10 -2 rem).
Various sets of severe environmental conditions were postulated for the dry storage
concepts. No design-basis environments were considered capable of causing a release of
radioactive material. Package failures resulting from unidentified defects or corrosion
were the only mechanisms identified for material releases from dry storage. Releases are
estimated to occur once every 10 years from the example facility and result in a 70-yr
accumulated dose to the maximum-exposed individual of 1.1 x 10-6 rem.
4.8.1.5 Non-Radiological Impacts of Accidents in the Once-Through Cycle
Disabling injuries and deaths will result from construction of waste management facil-
ities, as they do in construction of all facilities. Using estimates of man-hours involved
in facility construction and statistical injury and death rates for construcion activities
(13.6 disabling injuries and 0.17 deaths per million man-hours), we estimate that 110 dis-
abling injuries and less than two deaths will result from construction of a 3000 MTHM AFR