All assessments collected by the department pursuant to this part shall be in a separate fund and shall be used solely to carry out the purposes of this chapter. These funds may be invested and reinvested at the discretion of the state treasurer, and the interest from these investments shall be deposited to the credit of the fund and shall be available for the same purposes as all other money deposited in the Tennessee grain indemnity fund. The moneys in the Tennessee grain indemnity fund shall not be available for any purpose other than the payment of claims and for the administration of this chapter.