Virginia power thermal-hydraulic methods

Conference · Thu Jan 01 00:00:00 EST 1987 · Trans. Am. Nucl. Soc.; (United States)

OSTI ID:6810036

Anderson, R C; Harrell, J R; Basehore, K L

Virginia Power Company operates two nuclear units at Surry and another pair at North Anna, with rated thermal powers of 2441 and 2893 MW, respectively. In support of the operation of these units, the nuclear safety analysis group is required to perform departure from nucleate boiling ratio (DNBR) calculations. In order to perform DNBR in-house analyses, Virginia Power acquired the COBRA IIIc/MIT thermal-hydraulic (T/H) code in the mid-1970s. The COBRA code is used primarily to evaluate reload core designs. Additional applications include peaking factor evaluation and may include transient reanalysis. More recently, in an effort gain DNBR margin by taking credit for excessive conservatism in the methodology for treating key uncertainties, Virginia Power submitted a topical report that described a proposed statistical combination of those uncertainties. In an alternate approach to gain DNBR margin, Virginia Power submitted a topical report that describes the qualification of the proprietary WRB-1 DNBR correlation in COBRA. These reports have been combined in a recent North Anna submittal. The margin gain was used to support reanalysis of key DNBR events with more conservative assumptions, thus reducing the likelihood of future reload violations. Upon NRC approval, this submittal will greatly streamline the reload verification process, while providing core design flexibility and relaxing operational restrictions for North Anna.

• OSTI ID: 6810036
• Report Number(s): CONF-8711195-; TRN: 88-033392
• Journal Information: Trans. Am. Nucl. Soc.; (United States), Vol. 55; Conference: American Nuclear Society winter meeting, Los Angeles, CA, USA, 15 Nov 1987
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
HEAT TRANSFER
COMPUTERIZED SIMULATION
HYDRAULICS
NORTH ANNA-1 REACTOR
REACTOR SAFETY
NORTH ANNA-2 REACTOR
SURRY-1 REACTOR
SURRY-2 REACTOR
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MATHEMATICAL MODELS
REACTOR CORES
TRANSIENTS
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NUCLEATE BOILING
PHASE TRANSFORMATIONS
POWER REACTORS
PWR TYPE REACTORS
REACTOR COMPONENTS
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THERMAL REACTORS
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WATER COOLED REACTORS
WATER MODERATED REACTORS
210200* - Power Reactors
Nonbreeding
Light-Water Moderated
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