Question

Enriched boron is used in various nuclear applications including chemical shim in European pressurized water reactors. If boron is enriched to 60.0 wt.% B-10 and if the boron density is 2.305 g/cm3, determine the B-10 atom density.

Answer 1

Weight percentage is essentially the ratio of the mass of isotope to the total mass of the mixture multiplied by 100.

wt%= m_iso/m_tot *100

As mass= density * volume and volume for the isotope is the same as the total mixture, we can write

m_iso/m_tot =d_iso/d_tot where d is the density.

Thus, as per the given details, boron is enriched to 60 wt% B-10 and 40 wt% boron.

Therefore, for boron,

40 wt% = (2.305/dtot) *100

d_tot = (2.305/40)*100

d_tot = 5.7625 g/cm3

Therefore, to determine the atom density of B-10 ,

60 wt% = (d_B-10/ 5.7625) *100

d_B-10=60*5.7625/100

d_B-10=3.4575 g/cm3