DAMAGE TO, AND REPAIR OF THE HRE-2 CORE TANK

Journal Article · Wed Feb 01 04:00:00 EST 1961 · Power Engineering (U.S.)

OSTI ID:4063097

In two years operation of HRE-2, between January 1958 and February 1960, several cases of overheating and severe local corrosion, melting, or burning of materials in the core occurred, and two holes developed in the Zircaloy-2 core tank. The last hole occurred in January 1960. The perforated-plate flow diffusers were also attacked and some became detached from the wall. The performance of the reactor after the development of the first hole is discussed. It was found that uranium separated from the fuel solution (0.04M UO/sub 2/SO/sub 4/ in D/sub 2/O) in amounts proportional to the power level in the 1- to 3-Mw range. The corrosion specimens were badly corroded, and pieces fell from them on the diffuser screens. From visual inspection of the first hole, it appears to have formed by melting of the core wall at that point. On the other hand, the second hole may have formed by corrosion. Equipment was developed for remotely cutting the diffuser screens loose from the core wall and closing the holes. The repair operations were begun Feb. 27, 1960, and completed in August 1960. The possible reasons for the failures are discussed. Uranium can separate from UO/ sub 2/O/sub 4/ fuel solutions in several known ways, and severalfold increases in solution concentration could be obtained under unfavorable geometric and low flow conditions such as those in HRE-2. Upward flow with low velocity tends to cause solids to accumulate on surfaces below the core equator and thus to increase heating. It is concluded that a large homogeneous reactor plant will have to be designed with inventory control so that separation of fissionable materials can be detected before the reactivity becomes unoontrollable by the negative temperature coefficient. (D.L.C.)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-15-014016
• OSTI ID: 4063097
• Journal Information: Power Engineering (U.S.), Journal Name: Power Engineering (U.S.) Vol. Vol: 65: No. 2; ISSN POENA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BURNOUT
COMBUSTION
CONFIGURATION
CORROSION
DECOMPOSITION
DENSITY
DETECTION
FAILURES
FISSIONABLE MATERIALS
FUEL SOLUTIONS
HEATING
HEAVY WATER
HOMOGENEOUS REACTORS
HRE-2
LIQUID FLOW
MAINTENANCE
MELTING
PERFORMANCE
POWER
REACTIVITY
REACTOR CORE
REACTOR TECHNOLOGY
REACTORS
SULFATES
SURFACES
TEMPERATURE
TEMPERATURE COEFFICIENT
URANIUM
URANYL COMPOUNDS
VESSELS
ZIRCALOY