AMENDMENT NO. 2 to CREDIT AGREEMENT

EXHIBIT 10.30

AMENDMENT NO. 2

to

CREDIT AGREEMENT

               THIS AMENDMENT NO. 2 TO CREDIT AGREEMENT (the “Amendment”) is made as of March 31, 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 by an Amendment No. 1 dated as of February 6, 2004, and as further 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 Default” (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 Default, 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:

Amendments to the Credit Agreement. Effective as of March 31, 2004 and subject to the satisfaction of the
conditions precedent set forth in Section 4 below, the Credit Agreement is hereby amended as follows:

Section 1.01 of the Credit Agreement is hereby amended by adding the following term to such Section in
proper alphabetical order:

           “AB Technologies Acquisition” means the purchase by IITRI of substantially all of the assets of AB Technologies, Inc. pursuant to the terms and conditions set forth in the Asset Purchase Agreement, dated as of February 7, 2000 by and between IITRI, AB Technologies, Inc., Clyde Andrews and William Bewley, as in effect on the Closing Date and without giving effect to any subsequent amendment or modification thereto, and in respect of which the Borrower assumed all of the obligations of IITRI concurrently with the IITRI Acquisition.

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 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) fifty percent (50%) of Total Billed Receivables which are outstanding one hundred twenty-one (121) days or more from the date of original invoice, plus (b) 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, plus (c) ninety percent (90%) of the Net Amount of Eligible Receivables that are Eligible Billed Government Accounts Receivable as of such date, plus (d) eighty-five percent (85%) of the Net Amount of Eligible Receivables that are Eligible Billed Commercial Accounts Receivable as of such date, plus (e) sixty-five percent (65%) of the gross amount of Eligible Unbilled Government Receivables as of such date, and (iii) for any date of determination after September 30, 2004, the Borrowing Base (Monthly).

Subclause (e) of Section 7.4(C) of the Credit Agreement is hereby amended by deleting the text thereof in its
and replacing it with the following:

(e) cash payments in respect of purchase price adjustments, earn-outs or other similar forms of contingent purchase price during such period (exclusive of (x) cash purchase price adjustments related to the IITRI Acquisition paid on the Closing Date and (y) earn-outs related to the AB Techologies Acquisition paid during the fiscal year ending on September 30, 2004 to Clyde Andrews or William Bewly or to their designees), of at least (1) 1.20 to 1.00 as of the end of each fiscal quarter for the period commencing with the fiscal quarter ending on December 20, 2002 through the fiscal quarter ending September 30, 2003; (2) 1.25 to 1.00 as of the end of each fiscal quarter for the period commencing with the fiscal quarter ending on December 31, 2003 through the fiscal quarter ending March 31, 2006; and (3) 1.35 to 1.00 as of the end of each fiscal quarter thereafter.

Section 7.3 of the Credit Agreement is amended by adding the following clause (CC) to such Section:

(CC) The Borrower shall not sale, assign, transfer, convey or otherwise dispose of those certain Subordianted Notes and Seller Warrants purchased by the Borrower from Jonathan M. Emery on November 12, 2003.

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

The Exhibit J to the Credit Agreement (Form of Borrowing Base Certificate) is amended by deleting Section 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

Waiver. 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 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 Memorandum, dated as of November 13, 2003, executed by the Required
Lenders, (such Default being herein, the “Specified Default”) is hereby waived.

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

Representations and Warranties of the Borrower.

References to the Credit Agreement.

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.

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.

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]

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

REAFFIRMATION

               The undersigned hereby acknowledges receipt of a copy of the foregoing Amendment No. 2 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”)(as amended by an Amendment No. 1 dated as of February 6, 2004, and as further amended, restated, supplemented or otherwise modified from time to time, the “Credit Agreement”), which Amendment No. 2 is dated as of March 31, 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: March 31, 2004

HUMAN FACTORS APPLICATIONS, INC.