Exhibit 10.1

MODIFICATION #2

TO

THE UNSECURED NOTE AGREEMENT

THIS MODIFICATION #2 TO THE AGREEMENT made and entered into by and between
WILLIAM NICHOLSON and INTERNATIONAL ISOTOPES INC.  (hereafter “Company” or
“INIS”)

WITNESSETH:

WHEREAS, WILLIAM NICHOLSON has agreed to convert a portion of the unsecured note
into a convertible debenture private placement being offered by the Company, and
conducted through Euro Pacific Capital, and

WHEREAS, INIS is willing to accept conversion of a portion of the unsecured note
in lieu of a cash payment for the offering;

NOW, THEREFORE, in consideration of the above, the parties agree to modify the
original Agreement, dated April 1, 2002, and Modification #1 to the Agreement,
dated April 1, 2012, as follows:

1.

The $500,000 principal payment due on November 1, 2012 is reduced to $400,000.

2.

All other provisions of the Unsecured Note Agreement remain in full force and
effect.

IN WITNESS WHEREOF, the partied have executed this agreement as of the day and
year as signed below.

WILLIAM NICHOLSON

 

INTERNATIONAL ISOTOPES INC.

 

 

 

/s/ William Nicholson        /

 

/s/ Steve Laflin                   /