Module 15 In-plant accident management
- How can be abnormal operation prevented?
a)By taking into account the abnormal operating procedures (AOP).
b)By taking into account the operational limits that are defined in the technical specifications of the plant.
c)By controlling accidents within the design basis.
Correct answer: b).
- What is a design basis accident?
a)Accident conditions against which a nuclear power plant is designed according to establish design criteria, and for which the damage to the fuel and the releases of radioactive material are kept within authorized limits.
b)Accident conditions more severe than a design basis accident and involving significant core degradation.
c)An operational process deviating from normal operation which is expected to occur at least once during the operating lifetime of a facility but which, in view of appropriate design provisions, does not cause any significant damage to items important to safety nor lead to accident conditions.
Correct answer: a).
- Why does oxidation of zirconium with steam represent a problem during severe accident? (two correct answers)
a)It releases large amounts of decay heat.
b)Local releases energy, because it is exothermic reaction.
c)Releases of a large amounts of hydrogen.
d)It releases fuel pallet volatile fission products.
e)It causes control rod components vaporize.
Correct answers:b), c).
- What are the main threats to containment integrity? (multiple answers)
a)Containment over pressurization.
b)Release of fission products.
c)Steam explosions.
d)Direct containment heating.
e)Containment safety features.
f)Hydrogen combustion.
g)Core dewatering.
Correct answers: a), c), d), f).
- During which phase of severe accident is the most of fission product releasedinto containment in general?
a)Coolant activity release.
b)Gap activity release.
c)Early in-vessel release.
d)Ex-vessel release.
e)Late in-vessel release.
Correct answer: d).
- Why is pH of sump water maintained 8?
a)To dissolve the volatile fission products.
b)To limit re-vaporization and re-suspension of deposited materials.
c)To supress formation of volatile species of iodine.
Correct answer: c).
- Which statement about Emergency Operating Procedures (EOPs) and Severe Accident Management Guidelines (SAMGs) is correct?
a)EOPs are used to prevent or delay severe core degradation and are less prescriptive than SAMGs which are used to mitigate consequences of a severe accident involving significant core damage.
b)EOPs are used to mitigate consequences of a severe accident involving significant core degradation and are prescriptive; SAMGs which are less prescriptive are used to prevent or delay severe core damage.
c)EOPs are used to prevent or delay severe core degradation and are prescriptive; SAMGs which are less prescriptive are used to mitigate consequences of a severe accident involving significant core damage.
Correct answer: c).
- Which relations between safety function and their related instrumentation are correct?
a)Criticality is provided by steam generator water level.
b)Primary water inventory is provided by the primary water level.
c)Decay heat removal capability is provided by Tsat calculated from primary temperature and pressure.
d)Secondary water inventory is provided by the activity level measurements and the steam generator pressure.
e)Steam generator integrity is provided by the intermediate-range nuclear channels.
f)Containment status is provided by the containment pressure and dose rate.
Correct answers: b), c), f).
- Which plant conditions are included in Emergency Operating Procedures (EOPs)?
a)Anticipated operational occurrences.
b)Normal operation.
c)Design basis accidents.
d)Beyond design basis accidents.
Correct answers: a), c), d).