Table B-5. Decay Energy for Relevant Nuclides

DOE-STD-3013-2000

Table B-5

Decay Energy for Relevant Nuclides

Radio-

Half-life,

Decay Energy,

SHGR, Watts/kg

nuclide

Yr.

Mev/event

Watt-yr/mole

233

160,000

4.909

15,021

0.581

235

7.1 x 10

4.681

14,333

0.00006

238

4.5 x 10

4.195

12,836

0.000008

238

87.84

5.593

17,113

567

239

24,110

5.244

16,046

1.93

240

6,537

5.255

16,079

7.10

241

14.4

0.0205

62.7

12.52

242

376,000

4.983

15,246

0.116

241

432.2

5.637

17,248

114.8

Table B-6 provides expected isotopic compositions for a variety of circumstances. The three

columns with various "grades" of plutonium refer to material that has been recently discharged

from a reactor and reprocessed (recovering the plutonium from the uranium target is called

"reprocessing"). In each case, the americium content is zero because any that was formed

during irradiation or any cooling period prior to reprocessing, has been removed during

reprocessing. The last three columns, pertaining to Hanford materials, are for plutonium that

has been "aged" for 10-30 years, and has experienced a significant buildup of americium, and

238

241

240

Pu and

Pu. The percentage ranges refer to the

Pu content of the material. Note

decay of

that the first two categories of Hanford plutonium are similar to the Weapon Grade and Fuel

240

Pu content. The similarity is more apparent if the americium

Grade categories in terms of the

241

Pu, which, for these decay times, provides a reasonable

content is added to that of the

241

Pu content.

estimate of the original