EXHIBIT 10.7




                             OPTION TO PURCHASE AND
                             RIGHT OF FIRST REFUSAL


         THIS OPTION TO PURCHASE AND RIGHT OF FIRST  REFUSAL is made and entered
into as of the 2nd day of May,  2003,  by and between  ADRIAN  RAND  ROBISON and
DOROTHY  ROBIS  and wife,  referred  to herein  as  "Lessor"  and  INTERNATIONAL
ISOTOPES, INC., a Texas corporation, referred to herein as "Lessee".

                                    RECITALS:

         A.     Lessee  previously  entered into a Lease  Agreement  (the "Prior
Lease  Agreement")  and an Option to Purchase  and Right of First  Refusal  (the
"Prior Option to Purchase and Right of First Refusal) dated March 2: 2000,  with
Allen Ball,  acting not individually but as Trustee of the Allen Ball and Connie
Ball Living Trust created under Trust  Agreement  dated January 6, 1990, and any
amendments thereto ("Ball").

         B.     The interest of Ball in the Prior Lease  Agreement and the Prior
Option to Purchase and Right of First Refusal was  transferred by Ball to Lessor
in  connection  with  the  sale by Ball to  Lessor  of the  following  described
premises  and  all  improvements  located  thereon  situate  in  the  County  of
Bonneville, State of Idaho, to-wit (the "Leased Premises"):

                Lot 4,  Block 4, St.  Leon  Industrial  Park,  Division  No.  2,
                according to the recorded plat thereof.

         C.     Lessee and Lessor are now  entering  into a New Lease  Agreement
pertaining  to the Leased  Premises  which shall have a term which  commences on
August 1, 2003 (the "New lease Agreement").  In connection with the execution of
the New Lease Agreement, Lessor and Lessee have agreed to execute this Option to
Purchase  and Right of First  Refusal in  substitution  for the Prior  Option to
Purchase and Right of First Refusal.


                                   AGREEMENTS:

         NOW, THEREFORE, in consideration of the lease of the Leased Premises by
Lessee,  the mutual  covenants  set forth herein and for other good and valuable
consideration, the parties agree as follows:

         1.     This  Option  to  Purchase  and  Right  of First  Refusal  shall
substitute  for the Prior Option to Purchase and Right of First  Refusal and the
Prior to Option to  Purchase  and Right of First  Refusal  shall have no further
force and effect.  The right of first refusal and option to purchase  granted to
Lessee  herein shall be in effect only until the  expiration  of the term of the
New Lease Agreement. The right of first refusal and option to purchase set forth
herein may not be exercised by Lessee if:



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                (a)   Lessee or a sublessee  of Lessee  authorized  by Lessor is
         not in possession of the Leased Premises under the New Lease Agreement.

                (b)   Lessee is in  default of any of the terms of the New Lease
         Agreement.

         2.     Except as  otherwise  provided  for herein,  in the event Lessor
desires to sell, transfer or convey Lessor's interest in the Leased Premises, or
any portion  thereof,  Lessor  shall have the right to sell,  transfer or convey
Lessor's  interest in the Leased Premises,  or any portion  thereof,  only after
complying with the following requirements:

                (a)   Lessor shall forward to Lessee by certified  mail,  return
         receipt requested,  at 4137 Commerce Circle,  Idaho Falls, Idaho 83401,
         or to such other  address as Lessee  shall have  provided  to Lessor in
         writing,  written notice  containing all of the terms and conditions on
         which  Lessor  desires  to give,  sell,  transfer  or convey the Leased
         Premises,  or any portion thereof (the "Lessor's  Notice of Transfer").
         Said notice shall be deemed effective upon the date of its mailing.

                (b)   Upon mailing of Lessor's Notice of Transfer,  Lessee shall
         then have the option to purchase  the  interest of Lessor in the Leased
         Premises, or such portion thereof, as is referred to in Lessor's Notice
         of Transfer upon the same terms as set forth in such notice.

                (c)   Lessee may exercise its option to  purchase by mailing its
         written  notice of  exercise of  option to Lessor  within  fifteen (15)
         days from the  date of  mailing of the notice to Lessee. Such notice of
         exercise of option  shall be  forwarded  to Lessor by  certified  mail,
         return receipt requested,  at Post Office Box 95, Rexburg, Idaho 83440,
         or to such other  address as may be  designated in writing to Lessee by
         Lessor.  In the event Lessee  exercises  such  option,  then Lessee and
         Lessor  must,  within  fifteen  (15) days  after the  exercise  of such
         option,  enter into a binding written agreement for the transfer and/or
         the purchase of the Leased  Premises upon the same terms and conditions
         set forth in  Lessor's  Notice of  Transfer.  Notwithstanding  anything
         contained  in the  New  Lease  Agreement  to the  contrary,  if  Lessee
         exercises  such  option  to  purchase,  then the term  of the New Lease
         Agreement shall expire on the day of closing of the sales transaction.



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                (d)   In the event  that  Lessee  does not  desire  to  exercise
         Lessee's option to purchase,  Lessee shall, within fifteen (15) days of
         the mailing of Lessor's  Notice of Transfer,  mail by  certified  mail,
         return receipt requested,  to Post Office Box 95, Rexburg, Idaho 83440,
         or such  other  address  as Lessor  shall  have  provided  to Lessee in
         writing,  Lessee's  notice to Lessor that Lessee will not exercise said
         option.  If Lessee  fails to provide  such  notice that Lessee will not
         exercise  such  option,  and  Lessee  does not  exercise  the option as
         provided in paragraph 2(c),  then Lessor is hereby  empowered to record
         Lessor's  affidavit  to the effect that Lessee did not timely  exercise
         said option,  which  affidavit shall be conclusive as against Lessee of
         Lessee's  failure to exercise such option.  If Lessee fails to exercise
         such option in the manner provided in paragraph 2(c) above, then Lessor
         shall  have the  right to  forthwith  transfer  or  convey  the  Leased
         Premises or any portion  thereof  free and clear of this right of first
         refusal to whomsoever  Lessor  desires,  provided  that: (i) such sale,
         transfer or conveyance is  consummated  within one hundred eighty (180)
         days after the  expiration  of the time for Lessee to accept the offer,
         (ii) such sale,  transfer or conveyance is made in accordance  with the
         terms and conditions set out in Lessor's Notice of Transfer,  and (iii)
         the  purchaser  shall  receive  the  Leased  Premises  subject  to  any
         remaining  rights and obligations  Lessor and Lessee may have under the
         New Lease  Agreement.  If Lessee  fails to exercise  such option in the
         manner  provided in  paragraph  2(c) above,  then in such event  Lessor
         shall  have the  right to  forthwith  transfer  or  convey  the  Leased
         Premises  or any  portion  thereof  free  and  clear of the  option  to
         purchase hereinafter set forth.

                (e)   Notwithstanding  anything to the  contrary  herein,  it is
         specifically  understood  and agreed  that this right of first  refusal
         shall not apply to any transfer,  either with or without consideration,
         or whether by will, agreement, operation of law or otherwise, by Lessor
         to Immediate  Family.  "Immediate  Family"  means for  purposes of this
         paragraph,  Adrian Rand Robison and Dorothy Robison,  husband and wife,
         the lineal descendants of Adrian Rand Robison and Dorothy Robison,  the
         spouses of any such lineal  descendants  and the trustees of any trusts
         in which the  beneficiaries  of such  trusts  are any of the  foregoing
         mentioned  parties.  Any such  transfer to  Immediate  Family  shall be
         subject,  however,  to the  right  of  first  refusal  granted  by this
         Agreement,  and the Immediate Family shall be bound to comply with this
         right  of first  refusal  and any  subsequent  transfer  of the  Leased
         Premises or any portion thereof.

         4.     Subject to the  termination  of the option  granted herein under
the conditions set forth in paragraph 2(d) above,  Lessor grants unto Lessee the
exclusive  right and  option,  if Lessee  shall not be in  default of any of the
terms of the New Lease  Agreement,  to  purchase  the  Leased  Premises  and any
additions and  improvements  thereon,  together with  any improvements  that may
have been made  during the term of the New Lease Agreement,  upon and subject to
the following terms and conditions:

                (a)   Said  option  shall  be  exercisable  only  prior  to  the
         expiration of the term of the New Lease Agreement.


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                (b)   To exercise  this option,  Lessee shall  deliver to Lessor
         written  notification  of the date upon  which  Lessor is  prepared  to
         purchase  and close the  transaction  upon the terms  provided  herein;
         provided, however, that Lessor shall be given at least thirty (30) days
         notice of the date of such closing.

                (c)   Within  sixty (60) days  after  giving  written  notice of
         Lessee's  intent to  exercise  the  option to  purchase,  Lessee  shall
         purchase the Leased  Premises and the closing to complete such purchase
         shall be completed within said sixty (60) day period.

                (d)   If Lessee  properly  exercises  the option to purchase set
         forth herein, the Leased Premises shall be sold to Lessee by Lessor and
         Lessee shall  purchase the Leased  Premises  pursuant to the  following
         terms and provisions:

                      (i)   For  purposes  of this  subparagraph  the term "CPI"
                shall  refer  to the  CPI  published  by  the  Bureau  of  Labor
                Statistics  of the  United  States  Department  of Labor for All
                Urban  Consumers,  U.S.  City Average (All Cities) for all items
                with the index base being the current official base of 1982-1984
                = 100. If Lessee properly exercises the option to purchase prior
                to the  expiration  of the initial five (5) year term of the New
                Lease  Agreement,  the  purchase  price  shall  be  computed  as
                follows:  a fraction shall be created,  the denominator of which
                is the CPI for March, 2003, and the numerator of  which shall be
                the  CPI on the  last  day of the  month  prior  to the  date of
                closing.  This fraction then shall be multiplied by $709,587.00.
                The purchase  price shall be the higher of: (i)  $709,587.00  or
                (ii) the amount which is arrived at my  multiplying  $709,587.00
                by the above referred to fraction.

                      (ii)  If Lessee exercises the option to purchase set forth
                herein after the expiration of the initial five (5) year term of
                the New  Lease  Agreement,  the  purchase  price  of the  Leased
                Premises  shall be the fair market value of the Leased  Premises
                at the time Lessee  exercises the option to purchase.  If Lessee
                and Lessor cannot agree upon the fair market value of the Leased
                Premises, the Leased Premises shall be appraised.  If Lessee and
                Lessor cannot agree on an appraiser,  they shall each appoint an
                appraiser.  If the two (2) appraisers cannot agree upon the fair
                market value of the Leased Premises,  they shall appoint a third
                appraiser,  and the  decision  of a  majority  of the  three (3)
                appraisers  shall be  binding  on all  parties.  The cost of the
                appraisal shall be shared equally by the Lessor and the Lessee.

                      (iii) At closing,  Lessor  shall  execute a Grant Deed and
                deliver such Grant Deed to Lessee for recording which such Grant
                Deed shall transfer title to the Leased Premises to Lessee.  The
                Leased  Premises  shall be  transferred to Lessee subject to all
                existing easements or claims of easements,  patent reservations,
                rights-of-way,   protective  covenants,  zoning  ordinance,  and
                applicable building codes, laws and regulations,  encroachments,
                overlaps,  boundary  line disputes and other matters which would
                be disclosed by an accurate  survey or  inspection of the Leased
                Premises.


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                      (iv)  Lessee is  responsible  for payment of all taxes and
                assessments  accruing on the Leased  Premises during the term of
                the New Lease Agreement  between Lessee and Lessor. In addition,
                Lessee  shall  pay all  taxes and  assessments  levied  upon the
                Leased  Premises  from and after the date of closing  before the
                same become delinquent.

                      (v)   Lessor  shall  provide  to  Lessee  at the  time  of
                closing at Lessee's cost a standard form owners title  insurance
                policy in the amount of the purchase price insuring title to the
                Leased  Premises  in  Lessee,  free  and  clear  of any  lien or
                encumbrance,  excepting  any lien or  encumbrance  that may have
                attached  by reason of any act,  deed or  omission of Lessee and
                excepting  the  usual  printed  exceptions   contained  in  such
                policies of title  insurance,  and taxes and assessments for the
                current year.

                      (vi)  The Leased  Premises  shall be transferred to Lessee
                "as is" and Lessee  understands  that Lessor makes no warranties
                in regard to the Leased Premises, express or implied, except any
                warranties of title that may be otherwise contained in the Grant
                Deed from Lessor to Lessee.

                      (vii) Notwithstanding  anything contained in the New Lease
                Agreement to the  contrary,  if Lessee  exercises  the option to
                purchase set forth herein,  the term of the New Lease  Agreement
                shall expire on the day of closing of the sales transaction. The
                closing  on the  sale of the  transaction  shall be  handled  by
                Bonneville  Land & Title  Company,  and Lessor and Lessee  shall
                each  pay  one-half  (1/2)  of  the  closing  costs  charged  by
                Bonneville Land & Title Company.  Lessee shall be responsible to
                pay any and all costs incurred in connection with any loan which
                may be obtained by Lessee in connection with the purchase of the
                Leased  Premises,  including,  but not limited to, loan document
                preparation  fees,  tax service  fees,  appraisal  fees and loan
                origination fees.

         5.     This Agreement shall inure to the benefit of and be binding upon
the heirs,  successors and assigns of the parties hereto.

         6.     Should  either party  default in the  performance  of any of the
covenants or agreements contained herein, such defaulting party shall pay to the
other party all costs and expenses,  including, but not limited to, a reasonable
attorney fee, including such fees on appeal,  which the offended party may incur
in enforcing  this Agreement or in pursuing any remedy allowed by law for breach
hereof, whether such is incurred by the filing of suit or otherwise.



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         IN WITNESS  WHEREOF,  the parties have hereunto set their hands the day
and year first above written.

                                            LESSOR:



                                            /S/ Adrian Rand Robison
                                            -----------------------
                                            Adrian Rand Robison




                                            LESSEE:


                                            INTERNATIONAL ISOTOPES, INC.



                                            By:   /S/ Steve T. Laflin
                                                  -------------------

                                            Its:  President & CEO
                                                  -------------------







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