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Title: The VVER 440/230 confinement upgrade scoping study

Conference · · Transactions of the American Nuclear Society; (United States)
OSTI ID:5977072
;  [1]
  1. Westinghouse Electric Corp., Pittsburgh, PA (United States)

The VVER 440/230 nuclear power stations are currently being examined for safety improvements to meet internationally accepted safety criteria. Westinghouse has performed scoping analyses to evaluate different conceptual designs for modernization of the confinement systems. These designs represent alternatives for maintaining the confinement pressure below the 1-bar gauge (0.1-MPa) design pressure following a postulated loss-of-coolant accident (LOCA). These conceptual designs included the following: (1) adding a filtered vent to provide a release path to the atmosphere; (2) adding an auxiliary expansion volume to contain the mass and energy release; (3) adding an ice condenser unit to passively provide absorption of the energy released from the break. Each of these designs is intended to provide a means of handling the mass and energy released during the first 60 s of the LOCA. Thereafter, upgraded confinement spray and residual heat removal systems will provide the required pressure suppression and heat removal. Mass and energy release transients were generated for the VVER plant design for input into the confinement integrity evaluation. Three different hypothetical accidents were assumed: a 200- and 500-mm double-ended guillotine break and a 200-mm split break in the main reactor cooling piping. The transients were developed by scaling available best-estimate LOCA blowdown calculations and confirmed with RETRAN code calculations.

OSTI ID:
5977072
Report Number(s):
CONF-910603-; CODEN: TANSA
Journal Information:
Transactions of the American Nuclear Society; (United States), Vol. 63; Conference: Annual meeting of the American Nuclear Society (ANS), Orlando, FL (United States), 2-6 Jun 1991; ISSN 0003-018X
Country of Publication:
United States
Language:
English