Gamma-scanning the primary shield cavity under the TMI-2 reactor vessel
The March 28, 1979, accident at Three Mile Island Unit 2 (TMI-2) resulted in a significant mass of fuel debris (10 to 20 tonne) slumping into the bottom head of the reactor pressure vessel (RPV). It has been suggested that the lower shell could have been breached as a result of molten fuel slumping into the bottom head, which may have allowed fuel to escape into the primary shield cavity under the RPV. The primary shield cavity under the RPV was scanned to characterize the cavity, to determine if a significant deposit of fuel debris (i.e., 70 kg of UO/sub 2/) is within the cavity confines, and to support the characterization of the reactor building basement and the search for fuel outside the reactor coolant system. Prior to the reference scanning, key indicators, such as reactor coolant system pressure during and after the accident and measurements of in-core thermocouple lengths did not support the hypothesis of fuel escaping from the bottom of the vessel. However, no conclusive data existed on the lower head conditions and whether or not fuel escaped from this region. The scanning effort does not support the theory that a large quantity of fuel escaped through the RPV lower head.
- Research Organization:
- Burn and Roe, Middletown, PA
- OSTI ID:
- 6818912
- Report Number(s):
- CONF-861102-; TRN: 87-008107
- Journal Information:
- Trans. Am. Nucl. Soc.; (United States), Vol. 53; Conference: American Nuclear Society and Atomic Industrial Forum joint meeting, Washington, DC, USA, 16 Nov 1986
- Country of Publication:
- United States
- Language:
- English
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