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                                                                   EXHIBIT 10.29


                                 AMENDMENT NO. 1
                                       TO
                                CREDIT AGREEMENT


                  THIS AMENDMENT NO. 1 TO CREDIT AGREEMENT (the "Amendment") is
made as of February 6, 2004 by and among ALION SCIENCE AND TECHNOLOGY
CORPORATION (the "Borrower"), the institutions listed on the signature pages
hereof (the "Lenders"), and LASALLE Bank National Association, in its individual
capacity as a Lender and in its capacity as contractual representative (the
"Administrative Agent") under that certain Credit Agreement dated as of December
20, 2002 by and among the Borrower, the institutions from time to time parties
thereto as lenders, and the Administrative Agent (as amended, restated,
supplemented or otherwise modified from time to time, the "Credit Agreement").
Defined terms used herein and not otherwise defined herein shall have the
meaning given to them in the Credit Agreement.

                                   WITNESSETH

                  WHEREAS, the Borrower, the Lenders, and the Administrative
Agent are parties to the Credit Agreement; and

                  WHEREAS, the Borrower has requested that the Administrative
Agent and each Lender amend the Credit Agreement and waive the "Specified
Defaults" (as defined below), in each case, on the terms and conditions set
forth herein; and

                  WHEREAS, the Borrower, each Lender, and the Administrative
Agent have agreed to amend the Credit Agreement and waive the Specified
Defaults, in each case, on the terms and conditions set forth herein;

                  NOW, THEREFORE, in consideration of the premises set forth
above, the terms and conditions contained herein, and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto have agreed to the following amendments to the Credit Agreement:

                  1.       Amendments to the Credit Agreement.  Effective as of
December 19, 2003 and subject to the satisfaction of the conditions precedent
set forth in Section 4 below, the Credit Agreement is hereby amended as follows:


        1.1.      Section 1.01 of the Credit Agreement is hereby amended by
                  deleting the defined term "BORROWING BASE (SENIOR DEBT)"
                  thereof in its entirety and replacing it with the following:

                           "BORROWING BASE (SENIOR DEBT)" means, (i) for the
                  fiscal year ending September 30, 2003 and for the fiscal
                  period ending December 31, 2003, an amount, as set forth on
                  the most current Borrowing Base Certificate delivered to the
                  Administrative Agent, equal to the sum of (a) ninety percent
                  (90%) of all billed Receivables from any Account Debtor (other
                  than the Borrower, any


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                  Guarantor or an Affiliate of the Borrower or any Guarantor)
                  ("TOTAL BILLED RECEIVABLES") which are outstanding less than
                  one hundred twenty-one (121) days from the date of original
                  invoice as of such date, plus (b) sixty percent (60%) of Total
                  Billed Receivables which are outstanding one hundred
                  twenty-one (121) days or more from the date of original
                  invoice, plus (c) seventy-five percent (75%) of all unbilled
                  Receivables which may in accordance with Agreement Accounting
                  Principles be included as current assets of the Borrower or
                  any of its Subsidiaries notwithstanding that such amounts have
                  not yet been billed, plus (d) fifty percent (50%) of net
                  property, plants and equipment of the Borrower and its
                  consolidated Subsidiaries as of such date determined in
                  accordance with Agreement Accounting Principles, (ii) for the
                  fiscal periods ending March 31, 2004, June 30, 2004 and
                  September 30, 2004, an amount, as set forth on the most
                  current Borrowing Base Certificate delivered to the
                  Administrative Agent, equal to the sum of (a) ninety percent
                  (90%) of the Net Amount of Eligible Receivables that are
                  Eligible Billed Government Accounts Receivable as of such
                  date, plus (b) eighty-five percent (85%) of the Net Amount of
                  Eligible Receivables that are Eligible Billed Commercial
                  Accounts Receivable as of such date, plus (c) sixty-five
                  percent (65%) of the gross amount of Eligible Unbilled
                  Government Receivables as of such date, and (iii) as of any
                  date of determination thereafter, the Borrowing Base
                  (Monthly).

        1.2.      The Exhibit J to the Credit Agreement (Form of Borrowing Base
                  Certificate) is amended by deleting Line VI thereof in its
                  entirety and replacing it with the following:

                  VI.      CALCULATION OF BORROWING BASE (SENIOR DEBT) FOR
                  FISCAL YEAR ENDING SEPTEMBER 30, 2003 AND FOR THE FISCAL
                  PERIOD ENDING DECEMBER 31, 2003

        1.3.      The Exhibit J to the Credit Agreement (Form of Borrowing Base
                  Certificate) is amended by deleting Line VII thereof in its
                  entirety and replacing it with the following:

                  VII.     CALCULATION OF BORROWING BASE (SENIOR DEBT) FOR
                  FISCAL PERIODS ENDING MARCH 31, 2004, JUNE 30, 2004 AND
                  SEPTEMBER 30, 2004

        1.4.      Section 6.7(A) of the Credit Agreement is amended to delete
                  the reference to "Section 6.20" and to substitute therefor a
                  reference to "Section 6.21".

                  2.       Waivers. Effective as of the date of this Amendment
and subject to the satisfaction of the conditions precedent set forth in Section
4 below, the parties hereby agree that (i) the Borrower's non-compliance with
mandatory prepayment obligations of Section 2.5(B)(ii) of the Credit Agreement
for the period commencing on December 19, 2003 through and including the date
the conditions precedent set forth in Section 4 below shall have been satisfied
and (ii) certain Defaults arising by virtue of the Borrower's failure to
consummate the sale of the "Subject Investment" required under, and as such term
is defined in, that certain Consent


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Memorandum, dated as of November 13, 2003, executed by the Required Lenders,
(such Defaults under clauses (i) and (ii) being herein, the "Specified
Defaults") are hereby waived; provided, that, in the case of clause (ii) above,
such sale of the "Subject Investment" shall have occurred on or before March 31,
2004.

                  3.       Consent of the Administrative Agent and
Acknowledgement of the Lenders. Effective as of December 19, 2003 and subject to
the satisfaction of the conditions precedent set forth in Section 4 below, the
Administrative Agent hereby consents, under Section 7.3(N) to the Credit
Agreement, to the Borrower and its Subsidiary changing their fiscal year for
accounting and tax purposes from a period consisting of 52/53 calendar weeks
ending September 30 of each year to a period consisting of 12 months ending on
the last day of September of each year; provided that, for purposes of the
Credit Agreement and all other Loan Documents references to fiscal quarters
ending on or about March 12, July 2, September 30, or December 17 shall mean
March 31, June 30, September 30 and December 31, respectively; provided,
further, that, each Lender hereby acknowledges and agrees to the foregoing.

                  4.       Conditions of Effectiveness. The effectiveness of
this Amendment is subject to the conditions precedent that the Administrative
Agent shall have received the following:

        (a)       duly executed originals of this Amendment from each of the
                  Borrower, each Lender and the Administrative Agent;

        (b)       duly executed originals of a Reaffirmation in the form of
                  Attachment A attached hereto from each of the Borrower's
                  Subsidiaries identified thereon; and

        (c)       such other documents, instruments and agreements as the
                  Administrative Agent may reasonably request.

                  5.       Representations and Warranties of the Borrower.

        (a)       The Borrower hereby represents and warrants that this
                  Amendment, the attached Reaffirmation and the Credit
                  Agreement, as previously executed and as amended hereby,
                  constitute legal, valid and binding obligations of the
                  Borrower and its Subsidiaries parties thereto and are
                  enforceable against the Borrower and its Subsidiaries parties
                  thereto in accordance with their terms (except as
                  enforceability may be limited by bankruptcy, insolvency, or
                  similar laws affecting the enforcement of creditors' rights
                  generally).

        (b)       Upon the effectiveness of this Amendment and after giving
                  effect hereto, (i) the Borrower hereby reaffirms all
                  covenants, representations and warranties made in the Credit
                  Agreement as amended hereby, and agrees that all such
                  covenants, representations and warranties shall be true and
                  correct as of the effective date of this Amendment (unless
                  such representation and warranty is made as of a specific
                  date, in which case such representation and warranty shall be
                  true and correct as of such date) and (ii) no Default or
                  Unmatured Default has occurred and is continuing.

                  6.       References to the Credit Agreement.




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        (a)       Upon the effectiveness of Section 1 hereof, on and after the
                  date hereof, each reference in the Credit Agreement (including
                  any reference therein to "this Credit Agreement," "hereunder,"
                  "hereof," "herein" or words of like import referring thereto)
                  or in any other Loan Document shall mean and be a reference to
                  the Credit Agreement as amended hereby.

        (b)       Except as specifically amended above, the Credit Agreement and
                  all other documents, instruments and agreements executed
                  and/or delivered in connection therewith, shall remain in full
                  force and effect, and are hereby ratified and confirmed.

        (c)       The execution, delivery and effectiveness of this Amendment
                  shall not, except as expressly provided herein, operate as a
                  waiver of any right, power or remedy of the Administrative
                  Agent or the Lenders, nor constitute a waiver of any provision
                  of the Credit Agreement or any other documents, instruments
                  and agreements executed and/or delivered in connection
                  therewith.

                  7.       GOVERNING LAW.  THIS AMENDMENT SHALL BE GOVERNED BY
AND CONSTRUED IN ACCORDANCE WITH THE INTERNAL LAWS (INCLUDING 735 ILCS 105/5-1
ET SEQ., BUT OTHERWISE WITHOUT REGARD TO THE CONFLICT OF LAW PROVISIONS) OF THE
STATE OF ILLINOIS.

                  8.       Headings.  Section headings in this Amendment are
included herein for convenience of reference only and shall not constitute a
part of this Amendment for any other purpose.

                  9.       Counterparts.  This Amendment may be executed by one
or more of the parties to this Amendment on any number of separate counterparts
and all of said counterparts taken together shall be deemed to constitute one
and the same instrument.


                     [REMAINDER OF PAGE INTENTIONALLY BLANK]




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                  IN WITNESS WHEREOF, this Amendment has been duly executed as
of the day and year first above written.


                                 ALION SCIENCE AND TECHNOLOGY
                                 CORPORATION, as Borrower


                                 By:   /s/ J. M. Hughes
                                     -------------------------------------------
                                   Name:  J. M. Hughes
                                   Title:    Senior Vice President and Chief
                                               Financial Officer



                                 LASALLE BANK NATIONAL
                                 ASSOCIATION, as Administrative Agent and
                                 as a Lender


                                 By:   /s/ Scott D. Parsons
                                     -------------------------------------------
                                   Name:  Scott D. Parsons
                                   Title:    Vice President




                                 NCB CAPITAL CORPORATION, as a Lender


                                 By:   /s/ Meg Shrum
                                     -------------------------------------------
                                   Name: Meg Shrum
                                   Title:    Vice President



                                 BRANCH BANKING & TRUST COMPANY,
                                 as a Lender


                                 By:   /s/ Gregg E. Dougherty
                                     -------------------------------------------
                                   Name:  Gregg E. Dougherty
                                   Title:    Senior Vice President





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                                 U.S. BANK NATIONAL ASSOCIATION, as a
                                 Lender


                                 By:   /s/ Timothy A. Fossa
                                     -------------------------------------------
                                   Name:  Timothy A. Fossa
                                   Title:    Vice President



                                 ORIX FINANCIAL SERVICES, INC., as a
                                 Lender


                                 By:   /s/ Christopher W. Coulomb
                                     -------------------------------------------
                                   Name:  Christopher W. Coulomb
                                   Title:    Vice President




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                                                                    ATTACHMENT A

                                  REAFFIRMATION

                  The undersigned hereby acknowledges receipt of a copy of the
foregoing Amendment No. 1 to the Credit Agreement dated as of December 20, 2002
by and among ALION SCIENCE AND TECHNOLOGY CORPORATION (the "Borrower"), the
institutions from time to time parties thereto (the "Lenders"), and LASALLE Bank
National Association, a national banking association, in its individual capacity
as a Lender and in its capacity as contractual representative (the
"Administrative Agent"), which Amendment No. 1 is dated as of February 6, 2004
(the "Amendment"). Capitalized terms used in this Reaffirmation and not defined
herein shall have the meanings given to them in the Credit Agreement. Without in
any way establishing a course of dealing by the Administrative Agent or any
Lender, the undersigned reaffirms the terms and conditions of the Guaranty, the
Security Agreement and any other Loan Document executed by it and acknowledges
and agrees that such agreement and each and every such Loan Document executed by
the undersigned in connection with the Credit Agreement remains in full force
and effect and is hereby reaffirmed, ratified and confirmed. All references to
the Credit Agreement contained in the above-referenced documents shall be a
reference to the Credit Agreement as so modified by the Amendment and as the
same may from time to time hereafter be amended, modified or restated.

Dated:  February 6, 2004


HUMAN FACTORS APPLICATIONS, INC.


By:   /s/ J. M. Hughes
    --------------------------------------
Name:  J. M. Hughes
Title:  Treasurer