$10,000,000.00 March 23, 2000
REVOLVING LOAN PROMISSORY NOTE
FOR VALUE RECEIVED, the undersigned GSE SYSTEMS, INC., a Delaware corporation, GSE PROCESS
SOLUTIONS, INC., a Delaware corporation, and GSE POWER SYSTEMS, INC., a Delaware corporation
(collectively, BORROWERS), jointly and severally, promise to pay to the order of NATIONAL BANK OF
CANADA, a Canadian chartered bank (LENDER), at its New York branch, 125 West 55th Street, New York,
New York 10019, or at such other places as the holder of this Promissory Note may from time to time
designate, the principal sum of Ten Million Dollars ($10,000,000.00), or so much as has been advanced to the
BORROWERS as the proceeds of the LOAN, as such term is defined and described in the Loan And Security
Agreement of even date herewith (as the same may be amended, modified, extended, renewed, restated,
supplemented or replaced from time to time AGREEMENT between the LENDER and the BORROWERS,
together with interest on the unpaid principal balance from time to time outstanding at the rate or rates specified in
the AGREEMENT until paid in full and any and all other sums which may be owing to the holder of this
Promissory Note by the BORROWERS pursuant to this Promissory Note, on or before the TERMINATION
DATE, as such term is defined in the AGREEMENT, or such earlier date as is required by the AGREEMENT.
This Promissory Note is the NOTE, as such term is defined in the AGREEMENT. The following terms shall
apply to this Promissory Note.
1. Interest Rates, Calculation Of Interest, And Terms Of Repayment. The BORROWERS, jointly and severally,
promise to pay principal and all interest which accrues on the unpaid balance of this Promissory Note from the
date of this Promissory Note until such time as the obligations evidenced hereunder have been paid in full, at the
times and in accordance with the covenants, procedures and requirements set forth in the AGREEMENT.
Interest shall accrue, be payable, and shall be calculated