Virginia Power's generic main steam-line-break DNBR (departure from nucleate boiling ratio) analysis

Conference · Fri Jun 01 00:00:00 EDT 1990 · Transactions of the American Nuclear Society; (USA)

OSTI ID:6178887

Anderson, R C; Harrell, J R; Erb, J O

Virginia Power operates four nuclear reactors, two units each at the Surry and North Anna Power stations. The original operating licenses were based on acceptable analysis results of the accidents in the final safety analysis report (FSAR). The assumptions of these analyses must be verified on a reload basis. Included in these FSAR accidents is the main steam-line-break (MSLB) event. The plant FSARs describe the MSLB analyses, which is summarized as follows. The plant is assumed to be at hot zero power at end of life, when the moderator temperature coefficient (MTC) is most negative. The MSLB rapidly cools the secondary side, followed by a primary cooldown in one loop. The surge of cold water into the core, coupled with the negative MTC, results in high local power factors, which in turn can result in a violation of the departure from nucleate boiling ratio (DNBR) limit. The three-dimensional power distribution is calculated at several key state points. These distributions are then subjected to core thermal-hydraulic analysis by the COBRA code. The W-3 correlation is used to calculate the state-point DNBRs. Both the physics and the DNBR calculations have been repeated on a reload basis. As a result, Virginia Power has accumulated a reasonably large data base of MSLB DNBRs for both Surry and North Anna. Virginia Power now uses the power peaking factors criterion to verify that the MSLB analysis remains bounding on a reload basis.

• OSTI ID: 6178887
• Report Number(s): CONF-900608-; CODEN: TANSA; TRN: 91-008315
• Journal Information: Transactions of the American Nuclear Society; (USA), Vol. 61; Conference: American Nuclear Society (ANS) annual meeting, Nashville, TN (USA), 10-14 Jun 1990; ISSN 0003-018X
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
NORTH ANNA-1 REACTOR
REACTOR SAFETY
NORTH ANNA-2 REACTOR
REACTOR CORES
DEPARTURE NUCLEATE BOILING
STEAM SYSTEMS
RUPTURES
SURRY-1 REACTOR
SURRY-2 REACTOR
C CODES
HEAT TRANSFER
HYDRAULICS
MODERATORS
PIPES
POWER DISTRIBUTION
PRIMARY COOLANT CIRCUITS
REACTOR KINETICS
REACTOR LICENSING
REACTOR PHYSICS
REGRESSION ANALYSIS
SECONDARY COOLANT CIRCUITS
THREE-DIMENSIONAL CALCULATIONS
BOILING
COMPUTER CODES
COOLING SYSTEMS
ENERGY SYSTEMS
ENERGY TRANSFER
ENRICHED URANIUM REACTORS
FAILURES
FLUID MECHANICS
KINETICS
LICENSING
MATHEMATICS
MECHANICS
NUCLEATE BOILING
PHASE TRANSFORMATIONS
PHYSICS
POWER REACTORS
PWR TYPE REACTORS
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTORS
SAFETY
STATISTICS
THERMAL REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS
220900* - Nuclear Reactor Technology- Reactor Safety
210200 - Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled