Reduction of O&M costs using {open_quotes}new{close_quotes} source terms
- Stone & Webster Engineering Corp., Boston, MA (United States)
- Duquesne Light Company, Shippingport, PA (United States)
The licensing basis for reactor siting and postaccident plant performance for today`s operating plants is derived from a document published in 1962, TID 14844 (Ref. 1). The recently issued NUREG 1465 (Refs. 2 and 3), is the result of 30 yr of subsequent research on post-loss-of-coolant-accident (LOCA) fission product release and transport phenomena. It reflects what is generally known as the new, more realistic {open_quotes}physically based{close_quotes} source terms. The critical differences between the two guidance documents are the assumptions associated with the fission product release timing, quantity, and physical form. The instantaneous puff release of post-LOCA fission products postulated by TID 14844 is replaced by a more realistic release, starting some time after accident initiation and extending over a period of several hours. In addition, with the revised radioisotopic makeup of the new source term come different chemical and physical properties. Aerosol releases dominate rather than gaseous iodine, and the fractional composition of organic iodines is significantly less than previously assumed. These changes are beneficial because high particulate removal rates can be justified within the containment (or confinement), and the reduced fraction of organic iodines lowers the long-term contribution to control room and off-site doses. The use of the new source term results in a decrease of the estimated post-accident dose rate to the public. It also provides existing reactor licensees a basis for possible relaxation of current postaccident equipment performance requirements and elimination of selected engineered safety systems. This results in a reduction of operating and maintenance costs.
- OSTI ID:
- 186639
- Report Number(s):
- CONF-950601--
- Journal Information:
- Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 72; ISSN 0003-018X; ISSN TANSAO
- Country of Publication:
- United States
- Language:
- English
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