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

Comment
Number
2-15 2-16
Comment
Number
in accident number 6.2.8. The probability of accidents occurring where given in Table 6.2.6 for accident number 6.2.8 in 00E/ET-0028. An examinseveral
release mechanisms operate is less than the probability associated ation of the release fractions and cask inventories given in DOE/ET-0028
with accidents where only a few release mechanisms operate. Thus the risk indicates that the amount of radionuclides given in DOE/ET-0029 and hence
may be greater for the latter accident than the one involving many release the dose reported in Appendix N are in error. There are three sources of
mechanisms. Recommend the GEIS address these accidents that involve error. Mixed fission products and actinides have been excluded from the
several release mechanisms and show that either the risks involved are release, the amount of Kr85 released is underestimated, and the amount of
less than those of accident number 6.2.8 or if the risks are greater, this Cs 1 37 released has been overestimated.
more severe accident should be used as the umbrella source term for severe
accidents.
Finally, the following discussion shows that the amount of Cs134 and Cs 137
released for accident number 6.2.8 has been overestimated. The discussion
2.d.22 p. N4 on page 6.2.14 of 00E/ET/0028 indicates that 6 x 10-4 of the cesium inventory
Although the radiation dose to the maximum individual from postulated may be available for release as a result of fuel rod perforation in a high
accidents are given, the total population dose to persons in the vicinity temperature environment. This result is taken from Supplement II to
of the accident is not given. Since this is an important environmental WASH-1238. According to Table 6.2.6 of 00E/ET-0028, the availability
impact, it should be included in the GEIS in context with accident frequencies. fraction is divided in half between Cs 134 and Cs 137 . Table 3.3.8 of
DOE/ET-0028 shows a cask inventory of 1.7 x 10 5 curies and 9.4 x 104 P
The actual value for this population dose can be found on page 4.1.10 of curies per MTHM for Cs 134 and Cs 137 , respectively. Since acask contains
OOE/ET-0029. The 70 year dose commitment is given as 140 man-rem. Although 4 MTHM, this results in 6.8 x 10 5 curies of Cs 134 and 3.8 x 10 5 of Cs 137
the analysis uses a population density of 90 persons per square km for in a cask. Applying the availability fraction of 3 x 10-4 for each isotope
routine radiological impacts, the.population density used for the accident yields 204 curies of Cs 134 and 114 curies of Cs 137 available for release.
analysis is 130 person per square km. Note that population densities in Since in accident number 6.2.8, 50% of fuel rods are perforated, this results
suburban or urban areas can be at least an order of magnitude higher than in 102 curies of Cs 134 and 57 curies of Cs 137 being released in this accident.
this population density. A severe accident occurring in a suburban or Table 4.1.1-12 of DOE/ET-0029 shows 200 curies ofCs 134 and 110 curies of
urban area would, therefore, have a substantially greater environmental, Cs 137 being released. Perhaps the fact that only 50% of the rods are
impact than the accident consequences presented in the GEIS. In order perforated was not taken into account.
that all relevant impacts be included in the GEIS, recommend including the
consequences of severe accidents in high population density areas. We recommend that the radiation dose to the maximum individual resulting
from this accident be reevaluated in light of the above comments.
The largest accident dose reported in the GEIS results from a severe
accident involving a rail shipment of spent fuel. The resulting whole 2.d.23 p. N.4
body dose to the maximum individual is given as 120 rem for a one year The consequences presented in page N.4 for severe accidents are based on
period following the accident. The dose is based on the amount of the dose received by persons from radionuclides released to the atmosphere.
radionuclides released to the atmosphere as given in Table 4.1.1-12 of Since severe accidents may cause a reduction in shielding efficiency,
OOE/ET-0029. The amounts given in this table are based on release fractions doses resulting from radiation emanating directly from the cask should