U3O8 Corp. Increases NI 43-101 Uranium Resources by 125% in the Kurupung Project, Guyana

U3O8 Corp. (TSX VENTURE:UWE)(OTCQX:UWEFF), a Canadian-based company focused on
exploration for uranium and associated commodities in South America, reports an
increase of 125% in uranium resources estimated in accordance with National
Instrument 43-101 ("NI 43-101") from the Kurupung Project in Guyana (Figure 1).
The resource estimate reported today was undertaken by Watts, Griffis and McOuat
Limited, an independent consulting firm, on the Aricheng West and Aricheng C
structures using a cut-off grade of 0.05% U3O8, which yielded:




--  Indicated Resources of 2.6 million pounds ("Mlb") contained U3O8 at an
    average grade of 0.08% U3O8; and 
--  Inferred Resources of 6.3Mlb contained U3O8 at an average grade of 0.08%
    U3O8. 



Combined with the previously reported resource on Aricheng South and Aricheng
North (January 22, 2009 press release)(1), total uranium resources in the
Kurupung are:




--  Indicated Resources of 8.4Mlb contained U3O8 at an average grade of
    0.09% U3O8; and 
--  Inferred Resources of 7.7Mlb contained U3O8 at an average grade of 0.08%
    U3O8. 



"The doubling of the NI 43-101 resource is one more step on the path to showing
the large size potential of the Kurupung Project - and contributes to U3O8
Corp's rapidly growing resource portfolio in South America (Table 2)," said Dr.
Richard Spencer, U3O8 Corp's President and CEO. "The grades and style of
mineralization in the Kurupung confirm its similarity to other albitite-hosted
deposits such as Coles Hill in Virginia, Valhalla in Australia and Michelin in
Labrador, that each contain about 100Mlb of uranium resources (Table 3). The
Kurupung is on an exciting growth trajectory - we have now completed resource
estimates on four zones with uranium mineralization confirmed in another six
structures that are ready for infill drilling(1). We are confident that our
focused exploration strategy will result in the discovery of further shallow
targets to add to the inventory for resource expansion."


Uranium Mineralization in the Aricheng Area

Uranium in Aricheng West and Aricheng C is contained in near-vertical,
sheet-like breccias that extend from the saprolite at surface to at least 340
metres ("m") below surface at Aricheng West and 235m below surface at Aricheng
C. Mineralization in these two areas remains open at depth as well as along
strike. 


Field evidence suggests that uranium in the Aricheng area of the Kurupung
Project consists of one large system of linked structures - an interpretation
that has positive implications for resource growth potential (Figure 2). These
structures are marked by corridors of weak magnetism that are clearly visible in
geophysical data despite the dense jungle in which the project is located. Each
of the Aricheng South, Aricheng West, Aricheng North and Aricheng C resources
lies within one of these weakly magnetic areas. Results of our recent
exploration show conspicuous targets in adjacent magnetic low features (Figure
2) that we plan to investigate with scout drilling. New areas with significant
mineralization will be placed in the inventory of structures that are awaiting
infill drilling for resource estimation in due course.


Uranium mineralization in the Kurupung structures starts in the saprolite, or
soft clay layer, that extends from surface to a depth of between 20m and 80m
over the project area. This may represent an opportunity for low-cost mining
since removal of the clay would involve no blasting. Therefore, mining in the
Kurupung could potentially use open pit methods for extraction of near-surface
mineralization combined with underground mining of the deeper mineralization in
the minimally fractured, stable, granitic host-rock. 


Table 1 - Resource Summary for Aricheng C and Aricheng West

A summary of the resource estimates for the Aricheng C and Aricheng West
structures at various cut-off grades is detailed below. The base case cut-off
grade for the Aricheng resources, as highlighted below, is 0.05% U3O8. For a
direct comparison of the Aricheng resources to peer deposits (Table 3), use a
0.03% U3O8 cut-off.




----------------------------------------------------------------------------
Resource                                                                    
Category             Indicated                          Inferred            
----------------------------------------------------------------------------
Cut-off  Mineralized     Grade   Contained  Mineralized     Grade  Contained
grade       Material  (% U3O8)   U3O8 (lb)     Material  (% U3O8)  U3O8 (lb)
(%U3O8)     (tonnes)                           (tonnes)                     
============================================================================
Aricheng C:                                                                 
----------------------------------------------------------------------------
0.03         999,000      0.07   1,500,000    1,592,000      0.08  2,723,000
----------------------------------------------------------------------------
0.04         848,000      0.07   1,384,000    1,359,000      0.08  2,546,000
----------------------------------------------------------------------------
0.05         686,000      0.08   1,221,000    1,110,000      0.09  2,299,000
============================================================================
Aricheng West:                                                              
----------------------------------------------------------------------------
0.03       1,338,000      0.06   1,902,000    4,022,000      0.06  5,376,000
----------------------------------------------------------------------------
0.04       1,069,000      0.07   1,692,000    3,331,000      0.07  4,835,000
----------------------------------------------------------------------------
0.05         749,000      0.08   1,377,000    2,518,000      0.07  4,027,000
============================================================================
Total - Aricheng C & Aricheng West:                                         
----------------------------------------------------------------------------
0.03       2,337,000      0.07   3,402,000    5,614,000      0.07  8,099,000
----------------------------------------------------------------------------
0.04       1,917,000      0.07   3,076,000    4,690,000      0.07  7,381,000
----------------------------------------------------------------------------
0.05       1,435,000      0.08   2,598,000    3,628,000      0.08  6,326,000
============================================================================
Aricheng South                                                              
----------------------------------------------------------------------------
0.03       3,297,000      0.07   4,925,000      733,000      0.07  1,085,000
----------------------------------------------------------------------------
0.04       2,496,000      0.08   4,310,000      541,000      0.08    937,000
----------------------------------------------------------------------------
0.05       1,895,000      0.09   3,718,000      422,000      0.09    820,000
============================================================================
Aricheng North                                                              
----------------------------------------------------------------------------
0.03       1,235,000      0.09   2,485,000      487,000      0.07    742,000
----------------------------------------------------------------------------
0.04         970,000      0.11   2,282,000      329,000      0.09    621,000
----------------------------------------------------------------------------
0.05         782,000      0.12   2,096,000      223,000      0.11    518,000
============================================================================
Total Kurupung Resource - Aricheng Area                                     
----------------------------------------------------------------------------
0.03       6,869,000      0.07  10,812,000    6,834,000      0.07  9,926,000
----------------------------------------------------------------------------
0.04       5,383,000      0.08   9,668,000    5,560,000      0.07  8,939,000
----------------------------------------------------------------------------
0.05       4,112,000      0.09   8,412,000    4,273,000      0.08  7,664,000
----------------------------------------------------------------------------



Details of the Aricheng C and Aricheng West Resource Estimation



1.  The Mineral Resource estimate, effective May 22, 2012, was based on
    drill programs undertaken in 2009, 2010 and 2011. At Aricheng C,
    drilling comprised a total of 34 bore holes for 8,708m. At Aricheng
    West, drilling totalled 108 bore holes for 24,941m. 
    
2.  Mineral Resources were estimated using an inverse distance squared (ID2)
    block model, constrained to a geological model with a minimum horizontal
    width of 2m. No grade capping factor was used. A lower base case cut-off
    grade of 0.05 % U3O8 was used for reporting of the resources. For
    Aricheng C, a global specific gravity of 2.60 kg/m3 is assumed (2.09 in
    the saprolite). For Aricheng West, a specific gravity of 2.51 was used
    for resource blocks within the mineralized zones, and 2.02 within the
    saprolite. No deductions for mining recovery or otherwise were included
    in this estimate; 
    
3.  Mineral Resources were estimated using an assumed price of US$55/lb
    U3O8, and an exchange rate of US$0.95=C$1.00; 
    
4.  Mineral Resources which are not Mineral Reserves do not have
    demonstrated economic viability. The estimate of Mineral Resources may
    be materially affected by environmental, permitting, legal, title,
    socio-political, marketing, or other relevant issues; 
    
5.  The quantity and grade of reported Inferred Mineral Resources in this
    estimation are uncertain in nature and there has been insufficient
    exploration to define these Inferred Resources as an Indicated or
    Measured Mineral Resource and it is uncertain if further exploration
    will result in upgrading them to an Indicated or Measured Mineral
    Resource category; and 
    
6.  The Mineral Resources in this press release were estimated using the
    Canadian Institute of Mining, Metallurgy and Petroleum (CIM), CIM
    Standards on Mineral Resources and Reserves, Definitions and Guidelines
    prepared by the CIM Standing Committee on Reserve Definitions and
    adopted by CIM Council December 11, 2005. 
    



Table 2 - U3O8 Corp's Mineral Resources in Guyana, Colombia & Argentina(2)

Since the beginning of 2011, U3O8 Corp. has grown its NI 43-101 uranium
resources by nearly seven times from 5.8mlb Indicated and 1.3mlb Inferred on the
one property, the Kurupung Project in Guyana, to an expanding multi-commodity
resource portfolio across three lead projects in Guyana, Colombia and Argentina
as detailed in the below table.




-----------------------------------------------------------------
                                                                 
Project            NI 43-101      Tonnes          Grade          
                   Resource    (million)   U3O8    V2O5    P2O5  
=================================================================
Kurupung Project   Indicated         4.1   0.09%     --      --  
                  -----------------------------------------------
(Guyana)           Inferred          4.3   0.08%     --      --  
=================================================================
Berlin Project     Indicated         0.6   0.11%     --      --  
                  -----------------------------------------------
(Colombia)         Inferred          8.1   0.11%    0.5%    9.3% 
=================================================================
Laguna Salada      Indicated        47.3  60ppm  550ppm      --  
                  -----------------------------------------------
(Argentina)        Inferred         20.8  85ppm  590ppm      --  
-----------------------------------------------------------------

----------------------------------------------------------
                              Contained in Resource (Mlb) 
Project            NI 43-101  Uranium  Vanadium  Phosphate
                   Resource      U3O8      V2O5       P2O5
==========================================================
Kurupung Project   Indicated      8.4        --         --
                  ----------------------------------------
(Guyana)           Inferred       7.7        --         --
==========================================================
Berlin Project     Indicated      1.5        --         --
                  ----------------------------------------
(Colombia)         Inferred      19.9      97.0        0.8
==========================================================
Laguna Salada      Indicated      6.3      57.1         --
                  ----------------------------------------
(Argentina)        Inferred       3.8      26.9         --
----------------------------------------------------------



Laguna Salada - uranium and vanadium grades can be increased between 3 and 11
times by screening. For uranium, this would lead to a head grade of about
620-670ppm U3O8 from free-digging mineralization that lies at surface (see
September 21, 2011 press release). 


Table 3 - Reported Resources from Peer Abitite-Hosted Uranium Deposits(3)



----------------------------------------------------------------------------
                            Cut-Off  Measured &            Inferred         
                              Grade   Indicated    Grade   Resource    Grade
Deposit           Company    U3O8 %    Resource (U3O8 %) U3O8 (Mlb) (U3O8 %)
                                     U3O8 (Mlb)                             
----------------------------------------------------------------------------
Coles Hill        Virginia                                                  
Virginia, U.S.    Energy      0.025         119     0.06         --       --
----------------------------------------------------------------------------
Valhalla          Paladin                                                   
Queensland,       Energy                                                    
 Australia                    0.023          64     0.08         13     0.06
----------------------------------------------------------------------------
Skal              Paladin                                                   
Queensland,       Energy                                                    
 Australia                    0.023          20     0.06          2     0.05
----------------------------------------------------------------------------
Michelin          Paladin  0.05 U/G                                         
Labrador, Canada  Energy   0.02 O/P          84     0.09         53     0.08
----------------------------------------------------------------------------
(i)U/G = underground mining scenario; O/P = open pit mining scenario        



An updated NI 43-101 Technical Report on the Kurupung Project will be filed on
SEDAR shortly, and not later than 45 days from the issuance of this news
release.


The resource estimate reported here was undertaken by Mr. Kurt Breede, P. Eng.,
Senior Resource Engineer and Vice President, Marketing for Watts, Griffis and
McOuat Limited, a Qualified Person ("QP") within the definition of that term in
NI 43-101 of the Canadian Securities Administrators. Mr. Breede has verified and
approved the technical information relating to the Aricheng resources in this
release. 


All other scientific and technical information contained in this press release
has been prepared under the supervision of, and verified by Dr. Richard Spencer,
P. Geo, President & CEO of U3O8 Corp., a QP within the meaning of NI 43-101.


About U3O8 Corp. 

U3O8 Corp. is a Toronto-based exploration company, focused on exploration and
resource expansion of uranium and associated commodities in South America - a
promising new frontier for uranium exploration and development. U3O8 Corp. has
one of the most advanced portfolios of uranium projects in the region comprising
NI 43-101 resources in Guyana, Argentina and Colombia.


(1) Scout drilling results suggest that the ten Kurupung structures identified
to date may contain a conceptual target of 13-18 million tonnes at a grade of
0.08% to 0.10% U3O8 (estimated 30 to 35Mlb U3O8) including the NI 43-101
resource estimates reported on Aricheng North, Aricheng South, Aricheng C and
Aricheng West. Potential quantity and grade are conceptual in nature. There has
been insufficient exploration to define a mineral resource on six of the above
structures, and it is uncertain if further exploration will delineate such
targets as mineral resources.


(2) Mineral resources - Kurupung Project - see the January 14, 2009 technical
report: "A Technical Review of the Aricheng North and Aricheng South Uranium
Deposits in Western Guyana for U3O8 Corp. and Prometheus Resources (Guyana)
Inc." Berlin Project - see the March 2, 2012 technical report: "Berlin Project,
Colombia - National Instrument NI 43-101 Report." Laguna Salada Project - see
the May 20, 2011 technical report: "Laguna Salada Project, Chubut Province,
Argentina: NI 43-101 Technical Report: Initial Resource Estimate." The above
technical reports are available on U3O8 Corp's web site at www.u3o8corp.com and
on SEDAR at www.sedar.com. 


(3) Peer deposits have not been independently verified by U3O8 Corp. and
information regarding these deposits are drawn from publicly available
information. 


Forward-Looking Statements 

Certain information set forth in this news release may contain forward-looking
statements that involve substantial known and unknown risks and uncertainties.
These forward-looking statements are subject to numerous risks and
uncertainties, certain of which are beyond the control of U3O8 Corp., including,
but not limited to, the impact of general economic conditions, industry
conditions, volatility of commodity prices, risks associated with the
uncertainty of exploration results and estimates and that the resource potential
will be achieved on exploration projects, currency fluctuations, dependence upon
regulatory approvals, and the uncertainty of obtaining additional financing and
exploration risk. There is no assurance that the Kurupung resource will grow to
a similar size as peer deposits and that other targets in the Kurupung will add
to U3O8 Corp's resource base. Readers are cautioned that the assumptions used in
the preparation of such information, although considered reasonable at the time
of preparation, may prove to be imprecise and, as such, undue reliance should
not be placed on forward-looking statements. 


Figure 1 - Multiple Uranium-Bearing Structures in the Kurupung Batholith

To view Figure 1, please visit the following link:
http://media3.marketwire.com/docs/UWE2305_figure1.pdf.


Map of airborne magnetic data from the Kurupung area. The Kurupung Batholith
lies between northwest trending bounding shear zones (black dashed lines). Cool
colours (blue and green) represent rocks with poor magnetism while warm colours
(pink, red, orange and yellow) represent magnetic rocks. Most uranium found by
U3O8 Corp. to date lies within demagnetized faults (cool coloured areas). The
resources in Aricheng West and Aricheng C (labelled in red) reported today are
located on one of these weakly magnetic features in the Kurupung. 


White irregular areas show the footprints of uranium mineralization drilled by
U3O8 Corp. Resource estimates have now been completed on four zones (Aricheng
North, Aricheng South, Aricheng West and Aricheng C). Another six structures
(white irregular footprints) in the Aricheng and Accori areas are ready for
infill drilling in due course.


Figure 2 - Location of Mineralized Zones in the Aricheng Area

To view Figure 2, please visit the following link:
http://media3.marketwire.com/docs/UWE2305_figure2.pdf.


Close-up of the plan view of the Aricheng area with the footprint of mineralized
zones (black areas) located on a map of ground magnetic data. Uranium tends to
lie in areas of weak magnetism (blue tones) as evidenced by the Aricheng South,
Aricheng West and Aricheng C resources. Scout drilling has intersected
mineralization at Aricheng Alpha, Aricheng A and Sigma while soil geochemistry
(coloured circles) shows conspicuous zirconium anomalies in new target areas
(circled in white). Zirconium has been found to be a useful pathfinder element
in the Kurupung Project. Current exploration is focused on extending the soil
grid to cover the whole of the area shown in this map.


To view the image associated with this press release, "Kurupung Emerging into a
Large Uranium System in Guyana," please visit the following link:
http://www.marketwire.com/library/20120522-Kurupung_map_may_22_12.jpg.


To view the image associated with this press release, "Kurupung Project -
Airstrip Next to Base Camp in Guyana," please visit the following link:
http://www.marketwire.com/library/20120522-Guyana_airstrip_next_to_base_camp.jpg.