two chemistry or nuclear power questions

Tut 2 Nuclear

1. For the fission

235U + n → 141 Ba + X + 3 n + Q

Determine

a) the nuclide X

b) the energy Q released ( in suitable units)

assume the following atomic weights

235U : 235·0439299 u

141Ba : 140·9144064 u

neutron : 1·0086649 u

X: 91·9266528 u

Take the energy eqivalent of 1 amu from the data sheets.

2. A reactor with 100 tonnes of new natural uranium is operated with a neutron flux of 1017 neutrons m–2 s–1. Assume fission cross sections as follows are appropriate.

Microscopic cross-sections of 235U are for fission σf : 579 b

for capture σc : 101 b : this yields 236U.

Assume there are 200 MeV released per fission. Take electronic charge from the Data sheets

The proportion of 235U in natural unenriched uranium is 0·715% by weight.

Find a) the thermal power of the reactor under these conditions

b) Find the mass of 235U used in one day as a proportion of the original quuantity.

Hint work out a formula for the rate of removal of 235U.