Joint CE/EPRI Fuel Performance Evaluation Program, Task C. Evaluation of fuel rod performance in Maine Yankee Core I. Report on work performed up to July 1975

Technical Report · Mon Dec 01 04:00:00 EST 1975

OSTI ID:7267886

Fuhrman, N; Pasupathi, V

This is an interim report describing the progress up to July 1975, in evaluating the performance of the Maine Yankee Core I fuel and in particular, establishing the cause of initial clad perforation. Included are the results of the following tasks: (1) Poolside fuel inspection, (2) archive material examination, and (3) hot cell examination of selected representative fuel rods. Poolside inspection and hot cell examination found that grid-to-fuel rod contact wear was insignificant, thus demonstrating the successful wear-free operation of the Zircaloy grids. A major, unexpected hot cell result was the observation of two populations of fractional fission gas release (less than 1 percent, and 11.3 to 13.5 percent) among Batch B rods operating under similar irradiation conditions. Evidence of incipient perforation was found in one high gas release Batch B rod in the form of a pair of cladding cracks, originating at the clad internal surface, which appeared similar to those caused by volatile fission product stress corrosion. Fission product-assisted stress corrosion combined with pellet-cladding mechanical interaction is believed to have caused the formation and propagation of the cladding cracks. Based on the direct and circumstantial evidence available at this stage of the program, it is concluded that the most probable cause of initial cladding perforation in most of the leaking Maine Yankee Core I fuel rods was pellet-cladding interaction in combination with stress corrosion by volatile fission products (iodine and/or cesium).

• Research Organization: Combustion Engineering, Inc., Windsor, Conn. (USA)
• OSTI ID: 7267886
• Report Number(s): CENPD-221
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200* -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
CHEMICAL REACTIONS
CORROSION
CRACKS
ENRICHED URANIUM REACTORS
FUEL CANS
FUEL ELEMENTS
FUEL-CLADDING INTERACTIONS
MAINE YANKEE REACTOR
PERFORMANCE
POWER REACTORS
PWR TYPE REACTORS
REACTOR COMPONENTS
REACTORS
STRESS CORROSION
THERMAL REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS