Performance Improvement International is pleased to have these fine companies among our growing list of clients:
| ABB-Combustion Engineering | Maine Yankee Atomic Power | |
| Alstom Power | National Grid | |
| Ameren Services | Nebraska Public Power District | |
| American Electric Power | New Brunswick Power Corp. | |
| Areva NP, Inc. | New York Power Authority | |
| Arizona Public Service Co. | Niagara Mohawk Power Corp. | |
| Baltimore Gas & Electric Co. | North Atlantic Energy Service Corp. | |
| Baltimore Power & Light | Nuclear Management Co., LLC | |
| BHP Steel | Northeast Utilities | |
| BNFL Fuel Solutions | Northern States Power Co. | |
| Boston Edison Co. | Oak Ridge National Laboratory | |
| BP Global Management Services | Omaha Public Power District | |
| California Power Exchange | Ontario Hydro | |
| California Public Utilities Commission | Oregon Steel Mills | |
| Carolina Power & Light Co. | Pacific Gas & Electric Co. | |
| Centerior Energy | PECO Energy Co. | |
| CH2M Hill Hanford Group | Pennsylvania Power & Light Co. | |
| Chevron Products Co. | Pinnacle West Energy | |
| China Light & Power | Progress Energy | |
| Commonwealth Edison Co. | Public Service Electric & Gas Co. | |
| Connecticut Yankee Atomic Power | Rochester Gas and Electric Corp. | |
| Consolidated Edison Co. | Rocky Flats Environmental Technology | |
| Constellation Energy | Sandia National Labs | |
| Consumers Power | Sargent & Lundy Engineering | |
| Dannon Yogurt | Savannah River Site | |
| Daya Bay Nuclear Management Company, China | Scientech, Inc. | |
| Delcora Waste Treatment Plant | Shaw Areva Mox Services | |
| Detroit EdisonCo. | Shugart Thomson & Kilroy, APC | |
| Duke Energy Generation Services | Sithe Energies | |
| Duke Power Co. | South Texas Project | |
| Edison Mission | Southern California Edison Co. | |
| Electric Power Research Institute | Sulzer Pumps | |
| Electric Power Services | Sycamore Cogeneration | |
| Eli Lilly | Taiwan Power Company | |
| Evergreen International | Tennessee Valley Authority | |
| Entergy Operations, Inc. | Texas A&M University | |
| Exelon | Transnuclear West | |
| Florida Power & Light Co. | TU Electric | |
| Florida Power Corp. | U.S. Department of Energy | |
| Framatome ANP | U.S. Nuclear Regulatory Commission | |
| Frilot LLC | Union Electric | |
| Gerry Baby Products | Vectra Technologies | |
| GPU Nuclear Corp. | VEPCO | |
| GST Steel Rod Mill | Vermont Yankee Nuclear Power Corp. | |
| Hanford Operations | Virginia Power | |
| Houston Lighting & Power Co. | Washington Public Power Supply System | |
| Hughes Christensen | Watson Pharmacueticals | |
| Iberdrola, S.A. | Westinghouse | |
| Illinois Power Co. | Wholesome & Hearty Foods | |
| Indiana Michigan Power Co. | Wisconsin Power & Light | |
| Institute of Nuclear Energy Research | Wisconsin Public Service Corp. | |
| Kansas City Power & Light | Wolf Creek Nuclear Operating Corp. | |
| Komatsu Silicon America | Yankee Atomic Electric Co. | |
| Lincoln, Gustafson & Cercos Attorneys at Law | Zurn-EPC Services, Inc. | |