23.04.2013 Views

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

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

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

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

K.9<br />

TABLE K.1.4 Thermal Loadings Achieved at Conceptual Repositories<br />

Cycle Thermal Loading at Emplacement Salt Granite Shale Basalt<br />

Once-Through<br />

PWR<br />

kW/can 0.72 0.72 0.72 0.72<br />

Near-field local kW/acre 50 130* 80* 130*<br />

Far-field average kW/acre 40* 100 65 100<br />

BWR<br />

kW/can 0.22 0.22 0.22 0.22<br />

Near-field local kW/acre 50 130* 55 130*<br />

Far-field average kW/acre 40* 100 44 100<br />

U & Pu Recycle<br />

HLW<br />

kW/can 3.2 1.7 1.2 1.3<br />

Near-field local kW/acre 100* 130* 80* 130*<br />

Far-field average kW/acre 76 95 60 95<br />

RH-TRU (hulls)<br />

kW/can 0.32 0.32 0.32 0.32<br />

Near-field local kW/acre 100* 93 42 77<br />

Far-field average kW/acre 76 70 32 60<br />

* Denotes limiting thermal parameter.<br />

Predicted temperature histories over the first 100 years for the waste (center line)<br />

or spent fuel (center pin), the canister wall, and for the rock near the surface <strong>of</strong> the<br />

emplacement hole are shown for the design canister loadings in Figures K.1.9 through K.1.16.<br />

These temperatures correspond to the highest values obtained anywhere in the formation rock.<br />

The temperatures have been calculated in models with detailed treatment <strong>of</strong> the very-nearfield,<br />

including 15 cm <strong>of</strong> crushed formation material between the rock and the canister in<br />

the emplacement hole. Additional details <strong>of</strong> the models and analyses are contained in<br />

DOE/ET-0028. The results for PWR spent fuel canisters and the HLW canisters, respectively,<br />

in a salt formation are shown in Figures K.1.9 and K.1.10. The corresponding temperature<br />

histories for granite, shale and basalt are shown in Figures K.1.11 and K.1.12, K.1.13 and<br />

K.1.14, and K.1.15 and K.1.16 respectively.<br />

The temperature histories are all well within the temperature criteria in Table K.1.1<br />

except for the center pin temperature for spent fuel in basalt, which just reaches the 300°C<br />

criteria. One method <strong>of</strong> reducing these temperatures is elimination <strong>of</strong> the crushed backfill<br />

surrounding the emplaced canisters. Heat is transferred across the resulting air space more<br />

readily than through the crushed backfill material and results in cooler canister and clad-<br />

ding temperatures. A higher conductivity backfill material could also be used.<br />

A tabulation <strong>of</strong> the material properties used in making these thermal calculations is<br />

shown in Tables K.1.5 and K.1.6.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!