EPRI Core Protection Nantel| 73 QUESTIONS|
WITH COMPLEE SOLUTIONS
What is the primary safety concern for nuclear power plant operations? correct answer: Preventing significant radiation exposure to the public during routine and accident conditions.How is the primary safety concern for nuclear power plant operations achieved? correct answer: Employing fission product barriers and engineered safety features.Identify ways a core can fail correct answer: Any loss of core geometry, particularly into a configuration where cooling becomes impractical, is considered a core failure List three ways that the core has an inability to fully remove the heat created by the fuel correct
answer: 1. A failure of the heat removal systems
- An increase of heat created beyond the ability of the heat removal systems
- The inability to transfer heat from the fuel
- Reactor Coolant System (RCS) pressure boundary
- Containment
What are the three fission product barriers? correct answer: 1. fuel pellet and cladding
Prevents the escape of fission products from cladding correct answer: Fuel pellet and cladding (first fission product barrier) Contains the radionuclides that escaped the cladding or were produced outside the cladding
correct answer: RCS pressure boundary (second fission product barrier)
Holds radionuclides that have escaped from the RCS correct answer: Containment (third fission product barrier) The defense-in-depth policy states that a utility should: correct answer: 1. Design to prevent the occurrence of nuclear accidents
- Assume that accidents will occur
- Provide proven capability to meet the range of worst-case accidents
Defined as hypothesized events that affect one or more of the radioactive material barriers and
that are not expected during plant operations correct answer: Accidents
What are two accident types that are considered? correct answer: 1. Mechanical failure of a single component leading to the release of radioactive material from one or more barriers
- Arbitrary rupture of any single pipe up to and including complete severance of the largest pipe
in the nuclear system process barrier By definition, what is typically a worst-case accident of interest correct answer: Design Basis Accident (DBA) 1 / 2
When designing a plant, the philosophy documented in the FSAR contains several layers. Which of the following assumptions are used to ensure core protection? correct answer: a. The plant is operating in a given band via proper control
- The plant is assumed to be in steady state prior to the transient
- The plant is being operated within Technical Specifications
- It is the specification to which a plant is designed
A design basis accident is typically a worst-case accident of interest.... T/F correct answer: True
Primary safety concern for nuclear power plant operation is.... correct answer: the protection of the public from the release of fission products First line of defense is.... correct answer: keeping the core covered, cooled, and properly reactive The systems of the plant are designed with several layers of protection including.... correct
answer: automatic controls, alarms, and automatic protective systems.
The focus of accident mitigation is.... correct answer: protecting the reactor core is a quantitative assessment of the risk associated with plant operation and maintenance correct
answer: Probabilistic Risk Assessment (PRA)
Also known as Probabilistic Safety Assessment (PSA) What is the original goal of PRA? correct answer: To analyze and understand sever accident behavior, and then identify and fix the plant vulnerabilities What are the attributes of a PRA correct answer: 1. It realistically models plant design, plant procedures, and human performance
- It is a best estimate
- It is not a safety-related tool
- It is a mathematical model of all important plant systems using plant - specific data for critical
- It models the plant response for various initiating events using calculated systems reliabilities
- It takes into account realistically usable mitigating equipment
components
Several conservative (worst-case) assumptions are used to set the bounds for the design... correct
answer: - Worst case single failure of equipment
- Non-safety equipment not available during an accident
- Equipment providing no capability if not fully operable
- / 2
Baseline for plant configuration to mitigate the various design basis events. correct answer: Technical Specification's Limiting Condition for Operation (LCO) -Used in design and licensing -YES or NO answer