<PAGE>
                                                                 CONFIDENTIAL
 
                                                                EXHIBIT 10.13


                                                            DRAFT -- 1/19/99
                                                            ----------------


                             AMENDED AND RESTATED
                             CONSORTIUM AGREEMENT
                                        

     THIS AMENDED AND RESTATED CONSORTIUM AGREEMENT (this  "Agreement"), dated
as of January __ 1999, by and between the following parties:

     *MORRISON KNUDSEN CORPORATION, an Ohio corporation ("MK"), and

     *BNFL USA GROUP INC., a Delaware corporation ("BNFL-USA").


WITNESSETH

     WHEREAS:

     1.   MK and BNFL-USA entered into a Consortium Agreement, dated as of June
          24, 1998 (the "ORIGINAL AGREEMENT"), pursuant to which they formed a
          consortium for the purpose of acquiring the Energy Systems business
          (the "ESBU BUSINESS") and the Government Operations business (the
          "GESCO BUSINESS") of CBS Corporation ("CBS").

     2.   The Original Agreement set forth the agreement of MK and BNFL-USA
          concerning the basis on which the ESBU and GESCO Businesses would be
          owned, and the basis on which ownership, control and risk would be
          shared after the acquisition.

     3.   On June 24, 1998 MK and BNFL-USA organized WGNH Acquisition, LLC, a
          Delaware limited liability company ("WGNH"), for the purpose of
          entering into asset purchase agreements with CBS for the acquisition
          of the ESBU and GESCO Businesses and acting as a holding company for
          MK and BNFL-USA's interests in the ESBU and GESCO Businesses.  WGNH is
          the entity referred to as "Wesco" in the Original Agreement and the
          ownership, governance and management of WGNH are currently set forth
          in the Original Agreement.
<PAGE>
                                                                 CONFIDENTIAL 

     4.   WGNH entered into (i) an Asset Purchase Agreement, dated as of June
          25, 1998 (as it may be amended from time to time, the "ESBU PURCHASE
          AGREEMENT"), with CBS covering the acquisition by WGNH of the ESBU
          Business, and (ii) an Asset Purchase Agreement, dated as of June 25,
          1998 (as it may be amended from time to time, the ("GESCO PURCHASE
          AGREEMENT"), with CBS covering the acquisition by WGNH of the GESCO
          Business.  The ESBU Purchase Agreement and the GESCO Purchase
          Agreement are sometimes referred to individually as an "ASSET PURCHASE
          AGREEMENT" or collectively as the "ASSET PURCHASE AGREEMENTS".

     5.   Since the date of the Original Agreement (i) certain changes have
          occurred with respect to the scope of the GESCO Business, and (ii) MK
          and BNFL-USA have had further discussions with each other and with
          representatives of the United States government  and CBS concerning
          certain issues relating to the ownership and control of certain
          aspects of the ESBU and GESCO Businesses.  As a result of these
          changes and discussions WGNH will no longer act as a holding company
          for MK's and BNFL-USA's interests in the ESBU and GESCO Businesses and
          either by novation or assignment will transfer its rights and
          obligations under the Asset Purchase Agreements to other entities
          organized by the parties.

     6.   MK and BNFL-USA wish to amend and restate the Original Agreement in
          its entirety as set forth in this Agreement so as to set forth their
          revised agreement concerning the basis on which the ESBU and GESCO
          Businesses will be owned, and the basis on which ownership, control
          and risk will be shared after the acquisition.

     7.   MK and BNFL-USA intend to take certain actions and enter into certain
          other agreements as contemplated by this Agreement.

     8.   BNFL-USA has organized a new wholly-owned subsidiary, BNFL Nuclear
          Services, Inc., a Delaware corporation ("BNSI"), for the purpose of
          holding BNFL-USA's interests in the GESCO and ESBU Businesses.

     9.   Morrison Knudsen Corporation, a Delaware corporation ("MK-Delaware")
          which is the parent company of MK, and British Nuclear Fuels plc, a
          public limited company organized under the laws of England ("BNFL")
          which is the parent company of BNFL-USA, entered into guarantees of
          the obligations of MK and BNFL-USA, respectively, under the Original
          Agreement (the "ORIGINAL GUARANTEES") and wish to replace the Original
          Guarantees with guarantees of the obligations of MK and BNFL-USA and
          BNSI, respectively, under this Agreement in the form attached
          following the signature pages to this Agreement.
<PAGE>
                                                                  CONFIDENTIAL 

     NOW THEREFORE, in consideration of the premises and the mutual covenants
     and agreements contained in this Agreement, the Original Agreement,
     including the Exhibits thereto, is hereby amended and restated to read in
     its entirety as follows:

1.   FORMATION OF ADDITIONAL COMPANIES.
     --------------------------------- 

     1.1  Interim Companies.  MK and BNSI have organized the following limited
          -----------------                                                   
          liability companies (sometimes referred to individually as an "INTERIM
          COMPANY" and collectively as the "INTERIM COMPANIES"):

          (a)  MK/BNFL GESCO LLC, a Delaware limited liability company ("INTERIM
               GESCO"), the membership interests in which are owned on a 60/40
               basis by MK and BNSI, respectively, as set forth in greater
               detail in a limited liability company agreement dated as of
               October 10, 1998.

          (b)  MK/BNFL Commercial Nuclear Services LLC, a Delaware limited
               liability company ("INTERIM CNS"), the membership interests in
               which are owned on a 60/40 basis by MK and BNSI, respectively, as
               set forth in greater detail in a limited liability company
               agreement dated as of October 10, 1998.

     1.2  Organization.  Promptly after the date of this Agreement the parties
          ------------                                                        
          will organize the following corporations or limited liability
          companies (sometimes referred to individually as a "COMPANY" and
          collectively as the ("COMPANIES") under the names, to take effect from
          the closing of the Asset Purchase Agreements, set forth below and,
          prior to closing, under such other interim names as the parties may
          agree:

          (a)  Westinghouse Government Services Company LLC, a Delaware limited
               liability company ("WGS")

          (b)  Westinghouse Government Environmental Services Company LLC, a
               Delaware limited liability company ("WGES")

          (c)  Westinghouse Electric Company LLC, a Delaware limited liability
               company  ("WELCO")

          (d)  Such other entities as the parties deem necessary or desirable to
               carry out the intent of this Agreement but not otherwise in
               contradiction of the terms of this Agreement.

                                      -3-
<PAGE>
                                                                  CONFIDENTIAL
 
          If appropriate, the parties may reorganize Interim GESCO as WGES and
          Interim CNS as WELCO, in which case they will transfer their
          membership interests and make such other changes in the organizational
          documents of such companies as may be necessary to conform to the
          terms of this Agreement.

     1.3  Operating Agreements.  The ownership, management, operation, financing
          --------------------                                                  
          and other attributes of the Companies will be set forth in the
          respective articles of incorporation, by-laws, limited liability
          company agreements and related documents to be entered into with
          respect to each of the Companies and other necessary documents which
          will be consistent with the provisions of this Agreement.

2.   WGNH.
     ---- 

     2.1  Purpose.  WGNH's purpose will be to assign its rights and obligations
          -------                                                              
          under the Asset Purchase Agreements as contemplated by Sections 6.2
                                                                 ------------
          and 6.3 and to execute and deliver any appropriate amendments to the
              ---                                                             
          Asset Purchase Agreements that may be necessary prior to the date of
          such assignment.  Promptly after the assignment has been achieved the
          parties will cause WGNH to be dissolved.

     2.2  General.  The parties will cooperate with each other and take all
          -------                                                          
          necessary action to implement this Section 2.
                                             --------- 

3.   WGS.
     --- 

     3.1  Purpose.  The purpose of WGS will be to pursue business opportunities
          -------                                                              
          related to the Defense Program missions of the U.S. Department of
          Energy (the "DOE") and the U.S. Department of Defense (the "DOD").
          With effect from the GESCO Closing Date (as defined in Section 6.3(a))
                                                                 -------------- 
          WGS will

          (a)  own and operate those portions of the GESCO Business that are
               included in the WGS Operations (as defined in Section 6.1(a)),
                                                             --------------  

          (b)  submit bids to the DOE and the DOD for new classified defense
               programs to be awarded by the DOE or the DOD that are consistent
               with the objectives of the WGS Operations, and

          (c)  own 60% of the outstanding membership interests in WGES.

     3.2  Organization.  MK will organize WGS as a Delaware limited liability
          ------------                                                       
          company and will hold 100% of the membership interests of WGS.

                                      -4-
<PAGE>
                                                                   CONFIDENTIAL
 
     3.3  BNFL Passive Economic Right and Obligations.  BNSI will have
          -------------------------------------------                 

          (a)  a passive economic right to receive a portion of the gains,
               profits and losses of WGS and the WGS Operations, and

          (b)  an obligation to make additional contributions to WGS's funding
               requirements, and to provide financial assurances with respect to
               WGS,

          in each case as set forth in an agreement (the "WGS AGREEMENT") in the
          form attached as Exhibit B.
                           --------- 

     3.4  Management.
          ---------- 

          (a)  Management by Managers.  WGS will be managed by a board of
               ----------------------                                    
               directors or managers (the "BOARD") and by officers appointed by
               the Board.

          (b)  Board.  With effect from the GESCO Closing Date,  WGS will have a
               -----                                                            
               Board of seven directors appointed by MK, one of whom will be
               nominated by BNSI (the "BNFL DIRECTOR").  One of the MK appointed
               directors will serve as Chairman of the Board.  With effect from
               the GESCO Closing Date, Robert A. Tintsman, the chief executive
               of MK, will be appointed as Chairman. The parties will develop a
               mutually acceptable policy on dividends and distributions to be
               adopted by the WGS Board.

          (c)  Officers.  The Board will appoint a President and other officers
               --------                                                        
               as desired from time to time.  With effect from the GESCO Closing
               Date, James Gallagher will be appointed as President.  The
               officers will have the authority, responsibilities and duties as
               are customary for officers holding similar positions with respect
               to businesses conducted in corporate form and such additional
               authority, responsibilities and duties as the Board may delegate
               from time to time.  The BNFL Director will have no vote with
               respect to the election, appointment or tenure of any officers.

          (d)  FOCI and National Security Issues.  FOCI shall be addressed
               ---------------------------------                          
               through a FOCI Negation Plan consisting of Board resolutions, as
               reviewed and approved by the DOE (and the DOD as appropriate),
               copies of which are attached as Exhibit C (the "WGS FOCI NEGATION
                                               ---------                        
               PLAN").

                                      -5-
<PAGE>
                                                                   CONFIDENTIAL
 
          (e)  Approval.  All actions of the Board will be taken by majority
               --------                                                     
               vote except that, subject to the provisions of the WGS FOCI
               Negation Plan, the following actions will require the concurrence
               of the BNFL Director (except, in the case of clauses (i), (iii),
               (iv), and (v), to the extent such actions relate to the WGES
               Operations or to the proceeds of WGS's investment in WGES):

               (i)    disposition or financial encumbrance of all or
                      substantially all of WGS's property and assets;

               (ii)   dissolution, merger or consolidation of WGS;

               (iii)  major financing, which for the purposes of this Agreement
                      shall mean the incurrence of indebtedness for borrowed
                      money of more than $_______ in any single transaction or
                      $_________ in the aggregate; provided that the concurrence
                      of the BNFL Director shall not be required for the
                      approval of any refinancing of any financing previously
                      approved under this clause (iii) so long as the amount of
                      the indebtedness is not increased and the terms of the
                      refinancing are no less favorable to WGS than the original
                      financing;

               (iv)   commencement or settlement of major litigation, which for
                      the purposes of this Agreement means any action or
                      proceeding, whether involving a court action, arbitration,
                      mediation or other dispute resolution process, (A) in
                      which the amount in damages payable by any party may
                      reasonably be expected to exceed $2,000,000 or (B) may
                      reasonably be expected to result in any order or other
                      binding decision that would prevent WGS from carrying on
                      any material part of WGS's business;

               (v)    material changes to the dividend and distribution policy
                      of WGS;

               (vi)   assumption of material additional liabilities or purchase
                      of material additional assets through the submission of
                      bids for new contracts or the amendment of existing
                      contracts;

               (vii)  material changes to the lines of business conducted by
                      WGS; or

               (viii) such other matters as may be specified in the WGS
                      Agreement.

                                      -6-
<PAGE>
                                                                    CONFIDENTIAL
 
               Appropriate protections will be provided to ensure that funds are
               not distributed to MK or its affiliates via contract or any other
               mechanism that would frustrate or avoid BNSI's participation in
               the gains, profits and losses of WGS and the WGS Operations as
               contemplated by the WGS Agreement.
4.   WGES.
     ---- 

     4.1  Purpose.  The purpose of WGES will be to pursue business opportunities
          -------                                                               
          related to environmental remediation and waste management activities,
          including those of the DOE and the DOD.  With effect from the GESCO
          Closing Date, WGES will own and operate those portions of the GESCO
          Business that are included in the WGES Operations (as defined in
                                                                          
          Section 6.1(b)).
          --------------  

     4.2  Members.  WGES will have a single series of membership interests.  The
          -------                                                               
          members and their membership interests in WGES will be:

               WGS    --  60%
               BNSI   --  40%

     4.3  Management.
          ---------- 

          (a)  Management by Managers.  WGES will be managed by a board of
               ----------------------                                     
               directors or managers (the "BOARD") selected by the members, and
               by officers appointed by the Board.

          (b)  Board.  With effect from the GESCO Closing Date, WGES will have a
               -----                                                            
               Board of five directors consisting of two individuals selected by
               MK (the "MK DIRECTORS"), two individuals selected by BNSI (the
               "BNFL DIRECTORS") and one individual appointed by MK (the
               "OUTSIDE REPRESENTATIVE") who, absent DOE approval will have had
               no prior involvement with WGES, MK, BNSI or their respective
               parent, subsidiary or affiliated companies.  The Outside
               Representative will be appointed by MK, with the written approval
               of the DOE.  Each director will serve for a one-year term, and
               will be eligible for re-appointment in accordance with this
               subsection (b), provided that MK and BNSI shall have the right to
               replace their respective appointees at any time subject to the
               provisions of the Security Control Agreement referred to in
               subsection (d) below.  One of the MK Directors will serve as
               Chairman of the Board and, with effect from the GESCO Closing
               Date, Robert A. Tintsman will be selected as Chairman.  The
               parties will develop a mutually acceptable policy on dividends
               and distributions to be adopted by the WGES Board.

                                      -7-
<PAGE>
                                                                    CONFIDENTIAL
 
          (c)  Officers.  The Board will appoint a President and other officers
               --------                                                        
               as desired from time to time.  With effect from the GESCO Closing
               Date, the Board will appoint James Gallagher as President. The
               officers will have the authority, responsibilities and duties as
               are customary for officers holding similar positions with respect
               to businesses conducted in corporate form and such additional
               authority, responsibilities and duties as the Board may delegate
               from time to time.  The BNFL Directors will have no vote with
               respect to the election, appointment or tenure of any officers.

          (d)  FOCI and National Security Issues.  FOCI shall be addressed
               ---------------------------------                          
               through a FOCI Negation Plan consisting of  a Security Control
               Agreement, as reviewed and approved by the DOE (and the DOD as
               appropriate), a copy of which is attached as Exhibit D (the "WGES
                                                            ---------           
               SECURITY CONTROL AGREEMENT").

          (e)  Approval.  All actions of the Board will be taken by majority
               --------                                                     
               vote except that, subject to the provisions of the WGS Security
               Control Agreement, the following actions will require the
               concurrence of the MK Directors and the BNFL Directors:

               (i)   disposition or financial encumbrance of all or
                     substantially all of WGES's property and assets;

               (ii)  dissolution, merger or consolidation of WGES;

               (iii) major financing, which for the purposes of this Agreement
                     shall mean the incurrence of indebtedness of more than
                     $_______ in any single transaction or $_________ in the
                     aggregate; provided that the concurrence of the BNFL
                     Directors shall not be required for the approval of any
                     refinancing of any financing previously approved under this
                     clause (iii) so long as the amount of the indebtedness is
                     not increased and the terms of the refinancing are no less
                     favorable to WGES than the original financing;

               (iv)  commencement or settlement of major litigation, which for
                     the purposes of this Agreement means any action or
                     proceeding, whether involving a court action, arbitration,
                     mediation or other dispute resolution process, (A) in which
                     the amount in damages payable by any party may reasonably
                     be expected to exceed $2,000,000 or (B) may reasonably be
                     expected to result in any order or other

                                      -8-
<PAGE>
                                                                    CONFIDENTIAL
 
                      binding decision that would prevent WGES from carrying on
                      any material part of the WGES Operations;

               (v)    capital stock transactions, which for the purposes of this
                      Agreement means transactions involving the issuance or
                      transfer of any membership interests or other equity
                      interests in WGES;

               (vi)   material changes to the dividend and distribution policy
                      of WGES;

               (vii)  material increases in WGES=s liabilities through the
                      submission of bids for new contracts or the amendment of
                      existing contracts; or

               (viii) material changes to the lines of business included in the
                      WGES Operations.

               Appropriate protections will be provided to ensure that funds are
               not distributed to MK or its affiliates via contract or any other
               mechanism that would frustrate or avoid BNSI's participation in
               the gains, profits and losses of WGES and the WGES Operations as
               contemplated by this Agreement.

5.   WELCO.
     ----- 

     5.1  Purpose.  The purpose of WELCO will be to acquire and operate the ESBU
          -------                                                               
          Business and to pursue business opportunities related to commercial
          nuclear businesses and related matters.  With effect from the ESBU
          Closing Date (as defined in Section 6.3(b)) WELCO will
                                      --------------            

          (a)  own and operate all properties and assets that constitute the
               ESBU Business and are acquired by it under the ESBU Purchase
               Agreement, and

          (b)  lease and operate those portions of the Science and Technology
               Center that are related to the ESBU Business (the "STC"), as
               contemplated by Section 5.22 of the ESBU Purchase Agreement.

     5.2  Members.  BNSI will be the sole member of WELCO.  If Interim ESBU is
          -------                                                             
          reorganized as WELCO, MK will transfer to BNSI any membership interest
          held by it in Interim ESBU for nominal consideration.

     5.3  Management.
          ---------- 

                                      -9-
<PAGE>
                                                                    CONFIDENTIAL
 
          (a)  Management by Managers.  WELCO will be managed by a board of
               ----------------------                                      
               directors or managers (the "BOARD") elected by BNSI and by
               officers appointed by the Board.

          (b)  Board.  The size and composition of the Board will be determined
               -----                                                           
               by BNSI.  The initial Chairman of the Board will be John Taylor,
               the Chief Executive of BNFL.

          (c)  Officers.  The Board will appoint a President and other officers
               --------                                                        
               as required from time to time.  With effect from the ESBU Closing
               Date Charles W. Pryor will be appointed as the President.  The
               officers will have the authority, responsibilities and duties as
               are customary for officers holding similar positions with respect
               to businesses conducted in corporate form and such additional
               authority, responsibilities and duties as the Board may delegate
               from time to time.

          (d)  FOCI and National Security Issues.  The following provisions will
               ---------------------------------                                
               apply in order to address issues relating to national security.

               (i)    WELCO will take appropriate steps to mitigate any FOCI
                      issues that arise from existing activities included in the
                      ESBU Operations, including activities at the STC. If
                      necessary, these steps will include the novation of any
                      classified contracts to WGS or WGES, as appropriate.

               (ii)   WELCO will honor all existing commitments to the DOE with
                      respect to AP600 technology, including payment
                      commitments.

               (iii)  WELCO will comply with applicable U.S. Government export
                      regulations and will honor all commitments to the Nuclear
                      Regulatory Commission with respect to the nuclear
                      materials and other licenses currently held as part of the
                      ESBU Business.

               (iv)   There will be no common officers between WELCO and WGS.

6.   ACQUISITION OF ESBU AND GESCO BUSINESSES.
     ---------------------------------------- 

     6.1  Division of GESCO Operations.  The parties acknowledge that effective
          ----------------------------                                         
          as of the GESCO Closing Date the GESCO Business is to be divided into
          two components as follows:

                                     -10-
<PAGE>
                                                                    CONFIDENTIAL
 
          (a)  WGS.  All assets, properties, rights, obligations and liabilities
               ---                                                              
               included in the GESCO Business (including the outstanding shares
               of, or other equity interests in, any corporation or other legal
               entity in which any of such assets, properties, rights,
               obligations and liabilities are held) that arise from, relate to,
               or are used in connection with

               (i)    the Savannah River Management and Operations contract (the
                      "SAVANNAH RIVER M&O CONTRACT"), including the outstanding
                      shares of, or other equity interests in, Westinghouse
                      Savannah River Company, Inc. or any successor entity,

               (ii)   the Electro-Mechanical Division, and

               (iii)  the Safety Management Solutions contracts and operations,
                      including the outstanding shares of, or other equity
                      interests in, Westinghouse Safety Management Solutions,
                      Inc. or any successor entity,

               (iv)   any other part of the GESCO Business described in Section
                                                                      ---------
                      6.1(b)(ii) below that would otherwise be a part of the
                      ----------
                      WGES Operations (as defined in Section 6.1(b)) but only to
                                                     ---------------
                      the extent that it involves classified defense activities

               (collectively the "WGS OPERATIONS")

          (b)  WGES.  All assets, properties, rights, obligations and
               ----                                                  
               liabilities included in the GESCO Business (including the
               outstanding shares of, or other equity interests in, any
               corporation or other legal entity in which any of such assets,
               properties, rights, obligations and liabilities are held) that
               arise from, relate to, or are used in connection with

               (i)    the Safe Sites, WIPP, Anniston, Government Technical
                      Services Division and West Valley contracts and
                      operations, or

               (ii)   any other part of the GESCO Business that is not
                      specifically identified as part of the WGS Operations and
                      is not described in clause (i) above but only to the
                      extent that it does not involve classified defense
                      activities

               (collectively the "WGES OPERATIONS").

                                     -11-
<PAGE>

                                                                    CONFIDENTIAL
 
     6.2  Novation.  MK and BNFL-USA will use commercially reasonable efforts to
          --------                                                              
          obtain the consent of CBS to a novation of the Asset Purchase
          Agreements as follows:

          (a)  ESBU Purchase Agreement.  The parties will implement a novation
               -----------------------                                        
               of the ESBU Purchase Agreement so that (i) WELCO is substituted
               as a party in lieu of WGNH and succeeds to all WGNH's rights and
               obligations, (ii) WGNH is released from its obligations, and
               (iii) the existing guarantees issued by MK-Delaware, MK, BNFL and
               BNFL-USA remain in effect in support of WELCO's obligations.

          (b)  GESCO Purchase Agreement.  The parties will implement a novation
               ------------------------                                        
               of the GESCO Purchase Agreement so that (i) WGS and WGES are
               substituted as parties in lieu of WGNH and succeed to all WGNH's
               rights and obligations in a manner that is consistent with the
               division of the GESCO Business as outlined in Section 6.1, (ii)
                                                             -----------      
               WGNH is released from its obligations, and (iii) the existing
               guarantees issued by MK-Delaware, MK, BNFL and BNFL-USA remain in
               effect in support of WGS's and WGES's obligations.

     6.3  Assignment.  If the parties are unable to obtain the consent of CBS to
          ----------                                                            
          a novation of the Asset Purchase Agreements as described in Section
                                                                      -------
          6.2 then they will cause WGNH to assign its rights and obligations
          ---                                                               
          under the Asset Purchase Agreements as follows:

          (a)  GESCO Purchase Agreement. No later than the closing date under
               ------------------------                                      
               the GESCO Purchase Agreement (the "GESCO CLOSING DATE")

               (i)  WGS Operations.  WGNH will assign to WGS all WGNH's rights
                    --------------                                            
                    and obligations under the GESCO Purchase Agreement that
                    relate to the WGS Operations and (to the extent permitted
                    under the GESCO Purchase Agreement) the parties will cause
                    WGS to assume all such rights and obligations, including the
                    obligation to pay an appropriate portion of the Purchase
                    Price, to accept the assignment and transfer to it of all
                    the Acquired Assets, and to assume the Assumed Liabilities
                    (each as defined in GESCO Purchase Agreement ) that
                    constitute part of the WGS Operations.

               (ii) WGES Operations.  WGNH will assign to WGES all WGNH's rights
                    ---------------                                             
                    and obligations under the GESCO Purchase Agreement that
                    relate to the WGES Operations and (to the extent permitted
                    under the GESCO 

                                     -12-
<PAGE>
                                                                   CONFIDENTIAL 

                    Purchase Agreement) the parties will cause WGES to assume
                    all such rights and obligations, including the obligation to
                    pay an appropriate portion of the Purchase Price, to accept
                    the assignment and transfer to it of all the Acquired
                    Assets, and to assume the Assumed Liabilities (each as
                    defined in GESCO Purchase Agreement) that constitute part of
                    the WGES Operations.

          (b)  ESBU Purchase Agreement. No later than the closing date under the
               -----------------------                                          
               ESBU Asset Purchase Agreement (the "ESBU CLOSING DATE") WGNH will
               assign to WELCO all WGNH's rights and obligations under the ESBU
               Purchase Agreement, and all personnel being taken and all
               technology being acquired from the STC and (to the extent
               permitted under the ESBU Purchase Agreement and the GESCO
               Purchase Agreement) the parties will cause WELCO to assume all
               such rights and obligations, including the obligation to pay the
               Purchase Price and to accept the assignment and transfer to it of
               all the Acquired Assets, and to assume the Assumed Liabilities
               (each as defined in ESBU Purchase Agreement); provided that, if
               necessary, the parties will enter into appropriate arrangements
               in order to address FOCI and national security concerns with
               respect to any classified defense contracts included in the STC
               operations that form part of the Acquired Assets or the Assumed
               Liabilities, which arrangements may involve the novation of those
               contracts to WGS or WGES and corresponding financial arrangements
               to preserve WELCO's economic interests in such contracts.

          (c)  Certain Rights.  All of the rights, duties and obligations of
               --------------                                               
               WGNH under the ESBU Purchase Agreement and the GESCO Purchase
               Agreement that are not specifically addressed in this Agreement
               will be shared equitably among the Companies in a manner that is
               consistent with this Agreement.

          (d)  Closing Dates.  MK and BNFL-USA anticipate that the closing under
               -------------                                                    
               the ESBU Purchase Agreement and the GESCO Purchase Agreement will
               occur simultaneously.  However, the parties may by mutual
               agreement permit the closings to occur at different times.



     6.4  Contribution of Purchase Price to WGS, WGES and WELCO.
          ----------------------------------------------------- 

          (a)  Subject to the provisions of paragraph (b), no later than the day
               before the GESCO Closing Date and the ESBU Closing Date,
               respectively, MK and 

                                     -13-
<PAGE>

                                                                   CONFIDENTIAL 

               BNSI will provide funds to WGS, WGES and WELCO to enable them to
               pay the purchase price under the GESCO Purchase Agreement and the
               ESBU Purchase Agreement, as described in Exhibit A.
                                                        --------- 

          (b)  All of the contributions contemplated by paragraph (a), and all
               other contributions to be made to the Companies under Section 7
                                                                     ---------
               or otherwise, are expressly conditioned on the expiration of any
               and all applicable waiting periods under the Hart-Scott-Rodino
               Antitrust Improvements Act relating to the formation of the
               Companies and to the acquisition of the ESBU Business or the
               GESCO Business.

     6.5  Other Actions.  The parties will take all such other actions and will
          -------------                                                        
          cause their respective affiliates to take such other actions to cause
          WGNH, WGS, WGES and WELCO to perform all obligations to be performed
          by them under the GESCO Purchase Agreement or the ESBU Purchase
          Agreement, as the case may be.

7.   ADDITIONAL CONTRIBUTIONS.  The obligations of the parties to make
     ------------------------                                         
     additional contributions to any of the Companies to meet the needs of the
     Companies for funding are as follows:

     7.1  WGS. MK and BNSI shall be responsible for the cash and other funding
          ---                                                                 
          requirements of WGS in accordance with the terms of the WGS Agreement.

     7.2  WGES.  Any contributions required to be made to WGES must be approved
          ----                                                                 
          by the representatives of both MK and BNSI on the WGES Board and will
          be made in proportion to the respective membership interests of WGS
          and BNSI, as set forth in Section 4.2.
                                    ----------- 

     7.3  WELCO.  BNSI shall be solely responsible for the cash and other
          -----                                                          
          funding requirements of WELCO.

8.   FINANCIAL ARRANGEMENTS.
     ---------------------- 

     8.1  Replacement of Letters of Credit etc.  The parties acknowledge that
          ------------------------------------                               
          CBS and certain of its affiliates are presently obligated under
          certain letters of credit, performance bonds and similar obligations
          issued in connection with the ESBU Business and the GESCO Business
          (the "OUTSTANDING LETTERS OF CREDIT AND BONDS"), and that WGNH is
          obligated under the ESBU Purchase Agreement and the GESCO Purchase
          Agreement to replace the Outstanding Letters of Credit and Bonds with
          substitute financial arrangements at closing.  The responsibility of
          the parties to accomplish this will be allocated as follows:

                                     -14-
<PAGE>
                                                                    CONFIDENTIAL
 
          (a)  WGS.  MK and BNSI will jointly replace each of the Outstanding
               ---                                                           
               Letters of Credit and Bonds that secure or support obligations
               that arise from the WGS Operations with substitute financial
               arrangements on or before the GESCO Closing Date and will provide
               such credit support, including guarantees from MK and BNSI or
               their respective affiliates, as may be necessary to put such
               substitute financial arrangements into effect, in accordance with
               the terms of the WGS Agreement.

          (b)  WGES.  MK and BNSI will jointly replace each of the Outstanding
               ----                                                           
               Letters of Credit and Bonds that secure or support obligations
               that arise from the WGES Operations with substitute financial
               arrangements on or before the GESCO Closing Date and will provide
               such credit support, including guarantees from MK and BNSI or
               their respective affiliates, as may be necessary to put such
               substitute financial arrangements into effect; provided that the
               costs and liabilities of such actions and arrangements shall be
               shared between MK and BNSI on a 60/40 basis.

          (c)  WELCO.  BNSI will replace each of the Outstanding Letters of
               -----                                                       
               Credit and Bonds that secure or support obligations that arise
               from the ESBU Operations with substitute financial arrangements
               on or before the ESBU Closing Date and will provide such credit
               support, including guarantees from BNSI or its affiliates, as may
               be necessary to put such substitute financial arrangements into
               effect.

     8.2  Support for Additional Financing.  If any of WGS, WGES or WELCO wishes
          --------------------------------                                      
          to incur any indebtedness from any third party and in order to obtain
          such financing a guarantee or other form of credit support is required
          then the responsibilities of the parties to provide such guarantees or
          other support are as follows.

          (a)  WGS. MK and BNSI shall be responsible for providing guarantees or
               ---                                                              
               other credit support for WGS, and for the costs and liabilities
               of such actions and arrangements, in accordance with the terms of
               the WGS Agreement.

          (b)  WGES.  MK and BNSI shall be jointly responsible for providing
               ----                                                         
               guarantees or other credit support for WGES, and any costs and
               liabilities of such actions and arrangements shall be shared
               between MK and BNSI on a 60/40 basis.

                                     -15-
<PAGE>

                                                                    CONFIDENTIAL
 
          (c)  WELCO.  BNSI shall be responsible for providing guarantees or
               -----                                                        
               other credit support for WELCO.

9.   TEAMING.
     ------- 

     9.1  General.  The parties recognize that each of them and their affiliates
          -------                                                               
          as well as the Companies have complementary strengths with respect to
          the performance of services for the DOE and the DOD and that is in
          their mutual interest to cooperate in order to enhance the position of
          the Companies in bidding on DOE and DOD contracts.

     9.2  Cooperation.  Subject to national security requirements, export
          -----------                                                    
          controls, FOCI mitigation plans and contracting requirements (the
          "GOVERNMENTAL REQUIREMENTS"), the parties will cause the Companies to
          cooperate in order to ensure their ability to draw upon the full
          portfolio of current resources in commercial, DOE, DOD, scientific and
          technical consulting and laboratory services.  In recognition of the
          fact that WELCO may possess personnel and technology resources which
          could benefit the implementation of existing and future WGS and WGES
          contracts, such cooperation will include WELCO's commercially
          reasonable efforts, in accordance with this Section 9 and with Section
                                                      ---------          -------
          10,  to make available such personnel and technology resources to
          --                                                               
          support WGS and WGES and their subsidiaries and divisions in the
          conduct of government business.  It is the intention of the parties to
          share lessons learned in operational know-how and technology
          applications through personnel transfers, case studies and status
          seminars in a manner that is consistent with the provisions of this
          Agreement.

     9.3  Certain Defense and Other Programs.   WGS, WGES and WELCO will
          ----------------------------------                            
          cooperate, subject to Governmental Requirements and pursuant to
          appropriate commercial arrangements to be negotiated in good faith, to
          support WELCO's participation in  Defense Program initiatives.

     9.4  Bidding.  Subject  to Governmental Requirements and other applicable
          -------                                                             
          law, WGS and WGES in the areas of business respectively assigned to
          them will be the preferred vehicle for bidding primary Management and
          Operations and Management and Integration contracts on DOE and DOD
          sites with the objective of growing the value and enhancing the
          competitiveness of WGS and WGES consistent with the interests of MK
          and BNFL-USA.  If MK and BNFL-USA agree that it would not be
          advantageous or consistent with their interests to bid a specific
          contract through WGS or WGES, as the case may be, they shall agree on
          the appropriate vehicle for jointly bidding such contract, subject to
          the following sentence.  If either MK or 

                                     -16-
<PAGE>
 
                                                                    CONFIDENTIAL

          BNFL-USA believes that jointly bidding a specific contract (using any
          vehicle) would potentially have a material adverse impact on MK or
          BNFL-USA, then and only after MK and BNFL have attempted to resolve
          and have been unable to resolve any differences of opinion regarding
          the potential for material adverse impact, will MK or BNFL-USA (or
          their respective affiliates) be free to bid that contract directly or
          in concert with a different partner or partners, and WGS and WGES will
          not bid. Any disputes with respect to this Section 9.4 will be
          resolved pursuant to the procedures set forth in Section 12.

     9.5  MK Preferred Provider of EPCM and Facilities O&M Services.  Subject to
          ---------------------------------------------------------             
          Governmental Requirements and other applicable law, MK shall be the
          preferred supplier to WELCO (and to WELCO's customers where WELCO has
          the right to choose its customer=s suppliers) for planning,
          constructing, demonstrating, operating, maintaining, repairing, and
          upgrading nuclear power generation facilities and facilities of any
          kind in connection with WELCO's commercial nuclear and/or steam
          operations to the extent WELCO intends to contract with any party for
          such services (hereinafter referred to as "EPCM/O&M Services").
          Accordingly, WELCO will negotiate with MK in good faith (and will
          recommend MK and seek to encourage its customers to so negotiate with
          MK) to provide EPCM/O&M Services that MK is qualified to perform.  If
          WELCO desires to competitively bid EPCM/O&M Services and MK is
          qualified to perform such EPCM/O&M Services, MK shall have the right
          to perform such EPCM/O&M Services at the same price and subject to the
          same terms and conditions as the terms and conditions of a bona fide
          bid by a competitive bidder that WELCO would otherwise contract with
          to perform such services.  If WELCO does not believe MK is qualified
          to perform such EPCM/O&M Services then the matter will be resolved
          pursuant to the procedures set forth in Section 12.  The foregoing
          provisions of this Section 9.5 do not apply to the extent such
          EPCM/O&M Services are subject to statutory and/or regulatory
          requirements mandating competitive bidding and prohibiting the
          exercise by MK of such right.  In addition, the arrangements between
          MK and BNFL-USA provided for in this Section 9.5 are subject to
          arrangements, existing on the Closing Date, of WELCO or its
          predecessors or affiliates.

     9.6  General and Administrative Services.  It is the intention of the
          -----------------------------------                             
          parties that, subject to Governmental Requirements and pursuant to
          appropriate commercial arrangements to be negotiated in good faith,
          WGS, WGES and WELCO should share certain general and administrative
          services in order to provide such services in the most efficient and
          cost-effective manner.

     9.7  Employees.
          --------- 

                                     -17-
<PAGE>

                                                                    CONFIDENTIAL
 
          (a)  The parties acknowledge that they have committed to the DOE not
               to make any changes to the management teams of WGS or WGES except
               as provided in a Transition Agreement to be entered into between
               the Companies and the DOE (the "TRANSITION AGREEMENT").

          (b)  In order to support the performance of all DOD and DOE contracts,
               MK and BNSI will promote the free transferability of employees
               between the Companies, subject in all cases to applicable
               Governmental Requirements and the reasonable commercial
               requirements of the Companies and after consultation with the DOD
               or the DOE, as the case may be.

          (c)  Subject to the provisions of the Transition Agreement, if
               applicable, MK and BNSI will endeavor to keep the benefit
               arrangements for employees of the Companies similar to each
               other, portable and competitive.

          (d)  Subject at all times to the Governmental Requirements, WGS, WGES
               and WELCO shall establish an advisory committee made up of
               representatives chosen by each of the three Companies (the "HUMAN
               RESOURCES COMMITTEE") to discuss and provide non-binding
               recommendations to their respective presidents concerning the
               availability of WELCO personnel to assist WGS and WGES, taking
               into account the Governmental Requirements and the needs of the
               Companies.  The Human Resources Committee shall

               (i)    meet at least once each quarter, and at such other times
                      as they may mutually agree, for the purpose of discussing
                      anticipated personnel requirements and the availability of
                      such personnel for the ensuing 12 months, or for such
                      other periods as they may mutually agree,

               (ii)   make recommendations, if any, to their respective
                      presidents concerning the transfer or secondment of WELCO
                      personnel, subject to the Governmental Requirements, and

               (iii)  provide reports to the presidents of the Companies on such
                      personnel matters on at least a quarterly basis.

               The Companies shall cooperate in carrying out such
               recommendations of the Human Resources Committee as may be agreed
               to by each respective affected Company, subject to such changes
               as the Companies may agree upon and subject to the Governmental
               Requirements.  Notwithstanding the 

                                     -18-
<PAGE>

                                                                    CONFIDENTIAL
 
               foregoing provisions of this Section 9.7(d) the recommendations
                                            -------------- 
               of the Human Resources Committee shall not be binding on the
               Companies, and none of the Companies shall be required to
               implement the recommended actions of the Human Resources
               Committee if they are on terms that are commercially unreasonable
               for that Company.

          (e)  Any personnel seconded to WGS or WGES pursuant to this Section 9
                                                                      ---------
               shall be seconded on a cost pass-through basis, including a
               reasonable allocation of overhead.

10.  TECHNOLOGY SHARING ARRANGEMENTS.
     ------------------------------- 

     10.1  General.  The parties recognize that the Companies and their
           -------                                                     
           subsidiaries have technology (including intellectual property) that
           may be useful to, or complementary of, the technology of each other.
           It is the intention of the parties that the full range of such
           technology be reasonably available to the Companies in providing
           services to their customers, particularly the DOE and the DOD, in
           accordance with this Section 10 and the Governmental Requirements,
                                ----------                                   
           including, without limitation, consistent with the technology
           transfer mission of DOE and other restrictions and conditions on
           licensing and technology transfer contained in the Covered Contracts
           specified in the Transition Agreement.

     10.2  Cooperation.  Subject to the Governmental Requirements and pursuant
           -----------                                                        
           to appropriate commercial arrangements to be negotiated in good
           faith, the parties will cause the Companies to cooperate to share
           relevant technology to best serve their client interests and goals;
           provided, however, that such sharing does not result in the
           disclosure of protected technology or intellectual property rights to
           third parties or the disclosure of classified information, special
           nuclear material, Unclassified Controlled Nuclear Information,
           Official Use Only, and/or export controlled data entrusted to or held
           by any Company except as permissible pursuant to the Governmental
           Requirements, including but not limited to the NISD and applicable
           U.S. government laws and regulations. Specific limitations on such
           interactions will be addressed in a Technology Control Plan and
           Security Control Agreement to be mutually agreed by the affected
           Companies and approved by the DOE and (as appropriate) the DOD. To
           ensure that relevant technology residing in WELCO is available to
           WGES and WGS in the performance of their business and contractual
           obligations, WELCO technology will be made available in accordance
           with the procedures set forth in Section 10.5.
                                            ------------

                                     -19-
<PAGE>

                                                                    CONFIDENTIAL

 
     10.3. CBS Shared Technology Agreements.  Subject to the Governmental
           --------------------------------                              
           Requirements, the parties and their affiliates will enter into one or
           more technology sharing arrangements with CBS and certain of its
           affiliates, and certain third parties in connection with the
           transactions contemplated by the Asset Purchase Agreements (the "CBS
           SHARED TECHNOLOGY AGREEMENTS"). In order for WGS, WGES, and WELCO to
           obtain the benefit of the technology that is to be licensed
           thereunder, it will be necessary for them to enter into appropriate
           arrangements for the further sharing or licensing of such technology
           through sublicense arrangements which may require the prior approval
           of CBS (which may not be unreasonably withheld).

     10.4  WELCO Technology.  Recognizing that WELCO will possess technology and
           ----------------                                                     
           related resources that could benefit the delivery of goods and
           services under existing and future WGS and WGES contracts, BNSI will,
           and will cause WELCO to, make reasonable efforts to make available
           such technology (in compliance with the Governmental Requirements,
           confidentiality restrictions, and pre-existing contractual
           requirements) to support WGS and WGES, their subsidiaries, divisions
           and controlled affiliates, in the performance of U.S. government
           business. WELCO will own the AP600 technology (to the extent such
           technology is currently owned by CBS) and will abide by all
           requirements of the existing contracts regarding such technology that
           are assumed by WELCO pursuant to the ESBU Asset Purchase Agreement .

     10.5  Procedures for Technology Exchange.  Upon specific request and in
           ----------------------------------                               
           compliance with the Governmental Requirements, WELCO will make
           available to WGS and WGES such technology as shall be deemed
           reasonably necessary to support WGS or WGES in the performance of
           U.S. government business. Likewise, upon specific request and in
           compliance with the Governmental Requirements, WGS and WGES will make
           available to WELCO such technology as shall be deemed reasonably
           necessary to support WELCO's business activities. Such requests shall
           be made by the Company's representative on the Technology Exchange
           Committee ("TEC"), which shall be comprised of designated
           representatives from WGS, WGES, and WELCO. The TEC will meet at least
           quarterly, or more frequently if requested by a designated
           representative. Technology will be made available among the Companies
           in accordance with arms-length commercial terms and the Governmental
           Requirements. In the event technology resources requested are not
           reasonably available in WELCO or WGES, the members of TEC will work
           cooperatively to obtain the desired technology on acceptable
           commercial terms from other sources, consistent with the business
           goals of the entities represented on TEC. WELCO or WGES will not be
           required to provide technology on commercially unreasonable terms or
           contrary to their business interests.

                                     -20-
<PAGE>
 
                                                                    CONFIDENTIAL

     10.6  Agreements.  MK and BNFL-USA will cause their affiliates, including
           ----------                                                         
           the Companies, to enter into appropriate agreements to carry out the
           purpose of this Section 10.
                           ---------- 

11.  INDEMNIFICATION.
     --------------- 

     11.1  Background.  The parties acknowledge and agree that
           ----------                                         

           (a)  It is their intention to segregate the GESCO Business (which is
                in turn divided into the WGS Operations and the WGES
                Operations), and the ESBU Business by allocating them to the
                Companies as outlined in Section 6.
                                         --------- 

           (b)  It is their intention that the exposure of MK, MK-Delaware and
                their affiliates to liabilities arising from the GESCO Business
                or the ESBU Business, and the exposure of  BNFL, BNFL-USA , BNSI
                and their affiliates to liabilities arising from the GESCO
                Business be limited as set forth herein.

           (c)  In order to preserve the allocation of liabilities reflected by
                such actions, the parties agree that each of the parties and the
                Companies and their respective affiliates will be entitled to
                indemnification as set forth below.

     11.2  First and Second Tier Entities.  For the purposes of this Section 11
           ------------------------------                            ----------

           (a)  MK, BNFL-USA, BNSI and, if applicable, their parent companies
                are referred to as "FIRST TIER ENTITIES" and

           (b)  WGNH, WGS, WGES and WELCO, and their respective subsidiaries,
                are referred to as "SECOND TIER ENTITIES".
 
     11.3  Indemnification.  With respect to any liability or claim that arises
           ---------------                                                     
           from the business or operations of any Second Tier Entity (or any
           predecessor):

           (a)  WGS.  In the case of any liability of any kind or nature
                ---                                                     
                whatsoever (including liabilities existing on the GESCO Closing
                Date) that arises from the business or operations of WGS, WGS
                will indemnify and defend  MK-Delaware, MK, their affiliates,
                BNFL, BNFL-USA, BNSI and their affiliates, WGNH and any other
                Second Tier Entities and their affiliates and hold them harmless
                against any loss or expense arising from such liability or claim
                (including reasonable attorneys' fees but excluding
                consequential damages) ("LOSSES"); provided that

                                     -21-
<PAGE>

                                                                    CONFIDENTIAL
 
               (i)  there shall be excluded from indemnification any Loss that
                    is reflected in a reduction in the value of any equity
                    interest in WGS held by MK or its affiliates or in the
                    amounts payable to BNSI under the WGS Agreement, and

               (ii) the assets of WGS that are to be used to make any such
                    indemnification payments shall in any event exclude its
                    membership interest in WGES and any dividends, distributions
                    or other payments received by WGS, or payable to WGS, with
                    respect to such interest.

               If the assets of WGS are insufficient to perform the required
               indemnification and defense BNSI and MK will make appropriate
               payments to each other and their respective affiliates such that
               MK and its affiliates, on the one hand, and BNSI and its
               affiliates, on the other hand, (taking into account their
               economic participation in the Second Tier Entities) share any
               Losses as provided in the WGS Agreement and otherwise on a 60/40
               basis.

          (b)  WGES.  In the case of any liability of any kind or nature
               ----                                                     
               whatsoever  (including liabilities existing on the GESCO Closing
               Date) arising from the business or operations of WGES, WGES will
               indemnify and defend MK-Delaware, MK, their affiliates, BNFL,
               BNFL-USA, BNSI and their affiliates, WGNH and each of the other
               Second Tier Entities and their affiliates and hold them harmless
               against any Losses, provided that there shall be excluded from
               indemnification any Loss that is reflected in a reduction in the
               value of any equity interest in WGES held by MK or BNFL-USA, BNSI
               or their affiliates.  If the assets of WGES, as the case may be,
               are insufficient to perform the required indemnification and
               defense, BNFL-USA and MK will make appropriate payments to each
               other and their respective affiliates such that MK and its
               affiliates, on the one hand, and BNFL-USA and its affiliates, on
               the other hand, (taking into account their economic participation
               in the Second Tier Entities) share any Losses on a 60/40 basis.

          (c)  WELCO. In the case of any liability of any kind or nature
               -----                                                    
               whatsoever  (including liabilities existing on the ESBU Closing
               Date) that arises from the business or operations of WELCO, WELCO
               will indemnify and defend MK-Delaware, MK, their affiliates, WGNH
               and any other Second Tier Entities and their affiliates and hold
               them harmless against any Losses.  If the assets of WELCO are
               insufficient to perform the required indemnification and defense,
               BNFL-USA will indemnify, defend and hold harmless 

                                     -22-
<PAGE>
                                                                    CONFIDENTIAL

               MK-Delaware, MK, and their affiliates, and WGNH and any other
               Second Tier Entities and their affiliates.

     11.4  Limitations.  The provisions of this Section 11 shall be perpetual.
           -----------                          ----------                    

     11.5  Notice and Cooperation.  Any party that has, or believes that it may
           ----------------------                                              
           have, a claim for indemnification or other right to payment under
           this Section 11 will give prompt written notice to the other party
                ----------  
           and other relevant parties of the event or circumstances giving rise
           to such claim. The parties will cooperate with each other and their
           affiliates in the investigation and defense of any liability or claim
           that may be the subject of this Section 11.  Any disputes will be
                                           ----------                       
           resolved as provided in Section 12.
                                   ---------- 

12.  DISPUTE RESOLUTION.
     ------------------ 

     12.1  All disputes with respect to any matters that are the subject of this
           Agreement will, In the first instance, be referred to the Chief
           Executive Officers ("CEOS") of MK-Delaware and BNFL as
           representatives of their respective companies.

     12.2  If the dispute cannot be resolved by the CEO's within 60 days after
           it is referred to them, then either party may initiate mediation of
           the dispute in accordance with the Center for Public Resources Model
           Procedure for Mediation of Business Disputes.

     12.3  If the dispute has not been resolved within 60 days after the
           initiation of the  mediation procedure, or if either party will not
           participate in a mediation, it will then be subject to binding
           arbitration under the rules of the International Chamber of Commerce
           at a mutually agreeable venue. If MK and BNFL-USA are unable to agree
           on a venue, the arbitration will take place at a neutral site other
           than the United States or the United Kingdom.
 
13.  TERMINATION.  This Agreement will terminate automatically upon the
     -----------                                                       
     termination, for any reason, of the ESBU Purchase Agreement or the GESCO
     Purchase Agreement.  In addition, this Agreement, except for the provisions
     of Sections 11, 12, 14, and 15 hereof, shall terminate on the earliest date
     on which either BNFL or MK, directly or through one or more of their
     respective Affiliates, (i) no longer holds an interest in WGS and (ii) no
     longer holds an interest in WGES.

14.  CONFIDENTIAL INFORMATION.
     ------------------------ 

                                     -23-
<PAGE>

                                                                    CONFIDENTIAL

 
     14.1  The parties acknowledge that in order to carry out the purposes of
           this Agreement it will be necessary for them to disclose to the other
           party, and to its affiliates, confidential and proprietary
           information of the disclosing party or its affiliates.

     14.2  Each party will take reasonable actions to identify to the other
           party any information that is confidential or proprietary, which will
           include marking or identifying such information (in whatever form it
           may be embodied) as "Confidential". All such information is referred
           to as "CONFIDENTIAL INFORMATION".

     14.3  Each party will treat the other party's Confidential Information as
           confidential, will not disclose it to any other person (other those
           of its and its affiliates' officers, directors and representatives
           who need to know such information for the purpose of carrying out the
           transactions contemplated by this Agreement) or use it for any
           purpose other than carrying out the transactions contemplated by this
           Agreement.

     14.4  The restrictions imposed under this Section 14 shall remain in effect
                                               ----------                       

           (a)  with respect to any Confidential Information that constitutes a
                "trade secret" (as defined under the laws of the State of New
                York) of the disclosing party, so long as it remains a trade
                secret,

           (b)  with respect to other Confidential Information, so long as the
                parties jointly hold interests in any of the GESCO Business,
                whether through their respective investments in any of the
                Companies or otherwise and until the third anniversary of the
                date on which any such joint ownership is terminated.

     14.5  The restrictions imposed under this Section 14 shall not apply to any
                                               ----------                       
           Confidential Information that

           (a)  at the time of disclosure is available in the public domain or
                is known to the receiving party without breach of any obligation
                of confidentiality,
 
           (b)  is subsequently disclosed by a third party to the receiving
                party without any obligation of confidentiality, or

           (c)  is independently developed by the receiving party without breach
                of any obligation of confidentiality.

15.  MISCELLANEOUS.
     ------------- 

                                     -24-
<PAGE>

                                                                    CONFIDENTIAL
 
     15.1  Cooperation Prior to Closing.  During the period between execution of
           ----------------------------                                         
           this Agreement and the ESBU and GESCO Closing Dates, MK and BNFL-USA
           will consult regularly with respect to matters arising under the ESBU
           Purchase Agreement and/or the GESCO Purchase Agreement. Initiating
           formal disputes, challenges or allegations of breach against CBS
           under such agreements will require the agreement of MK and BNFL-USA.

     15.2  Integration.  This Agreement contains the entire understanding of the
           -----------                                                          
           parties with respect to the subject matter hereof, and supersedes the
           Original Agreement and all other prior understandings and agreements
           between them or their affiliates with respect to such subject matter.
           The parties expect that this Agreement will be superseded in whole or
           in part by one or more other written agreements between them (the
           "SUBSEQUENT AGREEMENTS"). Each Subsequent Agreement shall make
           specific reference to this Agreement and the provisions, if any, of
           this Agreement that are to be superseded by such Subsequent
           Agreement.

     15.3  Governing Law.  This Agreement is governed by and shall be construed
           -------------                                                       
           in accordance with the law of the State of New York, without regard
           to the principles of conflicts of laws.

     15.4  Assignment.  No party shall have the right to assign all or any part
           ----------                                                          
           of its rights or obligations under this Agreement without the written
           consent of the other party. This Agreement shall be binding upon and
           enure to the benefit of the parties and their respective permitted
           successors and assigns.

     15.5  No Third Party Beneficiaries.  Except for the Companies, this
           ----------------------------                                 
           Agreement is not intended to create any rights in any person that is
           not a party to this Agreement.

     15.6  No Partnership.  The parties do not intend to create, and this
           --------------                                                
           Agreement shall not be deemed to create, a partnership or agency
           relationship or any fiduciary duties between MK and BNFL-USA or any
           of their affiliates.

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed and delivered by their duly authorized officers or agents, all as of
the day and year first above written.


     MK                         MORRISON KNUDSEN CORPORATION


                                     -25-
<PAGE>
                                                                    CONFIDENTIAL

 
                              By:  ______________________________
                              Name:
                              Title:

     BNFL-USA                 BNFL USA GROUP INC.



                              By:  ______________________________
                              Name:
                              Title:



                                     -26-
<PAGE>
 
                                                                    CONFIDENTIAL

GUARANTEES

     1.   BNFL.  In consideration of the execution and delivery of this
          ----                                                         
          Agreement by MK, British Nuclear Fuels plc, a public limited company
          organized under the laws of England ("BNFL"), hereby unconditionally
          and irrevocably guarantees to MK-Delaware and MK the due and punctual
          payment and performance by BNFL-USA of all of its obligations under
          this Agreement (including without limitation its indemnification
          obligations under Section 11), the GESCO Purchase Agreement and the
                            ----------                                       
          ESBU Purchase Agreement.  This guarantee replaces the Original
          Guarantee executed by BNFL on June 24, 1998.

          Dated:   January __, 1999    BRITISH NUCLEAR FUELS plc



                                    By:  __________________________
                                    Name:
                                    Title:

     2.   MK.  In consideration of the execution and delivery of this Agreement
          --                                                                   
          by BNFL-USA, Morrison Knudsen Corporation, a Delaware corporation
          ("MK-DELAWARE"), hereby unconditionally and irrevocably guarantees to
          BNFL and BNFL-USA the due and punctual payment and performance by MK
          of all of its obligations under this Agreement (including without
          limitation its indemnification obligations under Section 11), the
                                                           ----------      
          GESCO Purchase Agreement and the ESBU Purchase Agreement.  This
          guarantee replaces the Original Guarantee executed by MK-Delaware on
          June 24, 1998.

          Dated: January __, 1999    MORRISON KNUDSEN CORPORATION



                                    By:  __________________________
                                    Name:                        
                                    Title:


                                     -27-
<PAGE>

                                                                    CONFIDENTIAL

 
                                   EXHIBITS


          THE REGISTRANT AGREES TO PROVIDE THE SECURITIES AND EXCHANGE
          COMMISSION, UPON REQUEST, WITH COPIES OF THE EXHIBITS HERETO.


                                     -28-