Fort St. Vrain operations and future

Abstract

June 1989 resulted in the highest electric generation month in the history of the Fort St. Vrain plant. This culminated an excellent operating period involving the first half of 1988. The plant was then shutdown in July on a scheduled outage to make repairs in the main steam drive section of all of the helium circulators. This outage was significantly extended due to problems with moisture ingress into the primary coolant felt to be primarily from the core support floor section of the liner cooling system. 1989 also marks the 10th anniversary of Fort St. Vrain as a commercial nuclear power plant. Electrical generation form this plant throughout this period has not been good, generally because of the prototypical nature of key plant components, primarily the helium circulators. Also, throughout this period there has been substantial increase in operations, maintenance, and fuel costs which could not be offset by the sale of electricity from the plant. As 1988 progressed, it became more and more evident that the financial burden of continuing to operate Fort St. Vrain could not be maintained by Public Service Company of Colorado (PSC). On December 5, 1988, the Board of Directors made a decision to permanently shutdown Fort St. Vrain on or before June 30, 1990. The lessons learned and operational experiences from Fort St. Vrain have been substantial for the development of the Gas-Cooled Reactor Program and in achieving a safe, commercially viable plant design for the MHTGR. Superb fuel performance has not only provided PSC with a radiologically clean plant, but has been the key to achieving significant safety attributes in the licensing of the MHTGR. Equipment performance for Fort St. Vrain on key components and systems such as the steam generators, purification system control rod drives, and many others has been factored into the design of the MHTGR. Additional benefits are anticipated as the plant completes its operating phase and goes through defueling and decommissioning. As primary system components become available and are physically evaluated, further valuable data will be secured for the benefit of the MHTGR.