Modeling operator actions during a small break loss-of-coolant accident in a Babcock and Wilcox nuclear power plant
A small break loss-of-accident (SBLOCA) in a typical Babcock and Wilcox (B W) nuclear power plant was modeled using RELAP5/MOD3. This work was performed as part of the United States Regulatory Commission's (USNRC) Code, Scaling, Applicability and Uncertainty (CSAU) study. The break was initiated by severing one high pressure injection (HPI) line at the cold leg. Thus, the small break was further aggravated by reduced HPI flow. Comparisons between scoping runs with minimal operator action, and full operator action, clearly showed that the operator plays a key role in recovering the plant. Operator actions were modeled based on the emergency operating procedures (EOPs) and the Technical Bases Document for the EOPs. The sequence of operator actions modeled here is only one of several possibilities. Different sequences of operator actions are possible for a given accident because of the subjective decisions the operator must make when determining the status of the plant, hence, which branch of the EOP to follow. To assess the credibility of the modeled operator actions, these actions and results of the simulated accident scenario were presented to operator examiners who are familiar with B W nuclear power plants. They agreed that, in general, the modeled operator actions conform to the requirements set forth in the EOPs and are therefore plausible. This paper presents the method for modeling the operator actions and discusses the simulated accident scenario from the viewpoint of operator actions.
- Research Organization:
- EG and G Idaho, Inc., Idaho Falls, ID (United States)
- Sponsoring Organization:
- USNRC; Nuclear Regulatory Commission, Washington, DC (United States)
- DOE Contract Number:
- AC07-76ID01570
- OSTI ID:
- 5417016
- Report Number(s):
- EGG-M-91372; CONF-9111124-5; ON: DE92011141
- Resource Relation:
- Conference: 1991 RELAP5/TRAC-B international users seminar, Baton Rouge, LA (United States), 4-8 Nov 1991
- Country of Publication:
- United States
- Language:
- English
Similar Records
Uncertainty analysis of minimum vessel liquid inventory during a small-break LOCA in a B W Plant: An application of the CSAU methodology using the RELAP5/MOD3 computer code
The effect of reactor vessel vent valves on SBLOCA (small-break loss-of-coolant accident) behavior of the UMCP 2 times 4 B W (Babcock and Wilcox) simulation loop
Related Subjects
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
PWR TYPE REACTORS
LOSS OF COOLANT
REACTOR OPERATORS
HUMAN FACTORS
COMPUTERIZED SIMULATION
DECISION MAKING
ECCS
EMERGENCY PLANS
HEAT TRANSFER
HYDRAULICS
R CODES
REACTOR SAFETY
ACCIDENTS
COMPUTER CODES
ENERGY TRANSFER
ENGINEERED SAFETY SYSTEMS
ENRICHED URANIUM REACTORS
FLUID MECHANICS
MECHANICS
PERSONNEL
POWER REACTORS
REACTOR ACCIDENTS
REACTOR PROTECTION SYSTEMS
REACTORS
SAFETY
SIMULATION
THERMAL REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS
220900* - Nuclear Reactor Technology- Reactor Safety
210200 - Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
990200 - Mathematics & Computers