Design of Nuclear Reactor (Module 4)

Module 04: Design of a nuclear reactor

TYPES OF NUCLEAR REACTORS

The usual types of moderator are:

(Several answers)

a)Enriched uranium;

b)Ordinary water (light water);

c)Deuterium (heavy water);

d)Boron acid;

e)Graphite;

f)Liquid metal (usually sodium);

Answers: b), c), e)

Which type of moderator is used in Fast Breeder Reactor – FBR?

a)Ordinary water (light water);

b)Deuterium (heavy water);

c)There is no moderator;

d)Boron acid;

e)Graphite;

f)Liquid metal (usually sodium);

Answer: c)

What are the four basic components of a PWR?

(Several answers)

a)Boiler

b)Nuclear reactor;

c)Steam generator;

d)Gas turbine

e)Steam separator;

f)Turbine – generator;

g)Condenser;

Answers: b), c), f), g)

What is the reactor coolant in BWR?

a)Ordinary water which does not boil in the reactor;

b)Ordinary water which boils in the reactor;

c)Heavy water under pressure;

d)Coolant is gas;

e)Liquid sodium;

Answer: b)

Which type of power reactor is the most common worldwide?

a)Fast Breeder Reactor – FBR;

b)Light Water Graphite moderated Reactor – LWGR;

c)Gas Cooled Reactor – GCR;

d)Pressurized Water Reactor – PWR;

e)Pressurized Heavy Water Reactor – PHWR;

f)Boiling Water Reactor – BWR;

g)Advanced Gas-cooled Reactor – AGR;

Answer: d)

DESIGN OF RESEARCH REACTORS

What is the most common use of the research reactor?

(Several correct answer.)

a)Neutron activation analysis

b)Radioactive isotopes production

c)Scattering experiments for determination of material structures

d)Neutron radiography

Answer: All

What are the most common typesof research reactor?

(Several correct answer.)

a)Fast Breeder Reactor – FBR;

b)Light Water Graphite moderated Reactor – LWGR;

c)Open pool reactor;

d)Closed tank reactor;

e)Gas Cooled Reactor – GCR;

f)Pressurized Water Reactor – PWR;

g)Pressurized Heavy Water Reactor – PHWR;

h)Boiling Water Reactor – BWR;

i)Advanced Gas-cooled Reactor – AGR;

Answers: c), d)

SAFETY CONCEPTS IN THE DESIGN OF NUCLEAR REACTORS

What is the fundamental safety objective for nuclear installation?

a)The fundamental safety objective is to protect administration building on the site.

b)The fundamental safety objective is to protect people and the environment from harmful effects of ionizing radiation.

c)The fundamental safety objective is to protect national electrical system.

d)The fundamental safety objective is to prevent climate changes.

Answer: b)

What is the purpose of first level of defence?

a)Its aim is to detect and control deviations from normal operational states in order to prevent anticipated operational occurrences at the plant from escalating to accident conditions.

b)Its aim is to mitigate the consequences of accidents that result from failure of the third level of defence in depth.

c)Its aim is to prevent deviations from normal operation and the failure of items important to safety.

d)Inherent and/or engineered safety features, safety systems and procedures must be capable of preventing damage to the reactor core or significant off-site releases and of returning the plant to a safe state.

e)Mitigation of the radiological consequences of potential releases of radioactive materials that may result from accident conditions.

Answer: c)

What is the purpose of second level of defence?

a)Its aim is to detect and control deviations from normal operational states in order to prevent anticipated operational occurrences at the plant from escalating to accident conditions.

b)Its aim is to mitigate the consequences of accidents that result from failure of the third level of defence in depth.

c)Its aim is to prevent deviations from normal operation and the failure of items important to safety.

e)Mitigation of the radiological consequences of potential releases of radioactive materials that may result from accident conditions.

Answer: a)

BASIC SAFETY FEATURES OF THE DESIGN

Wherever possible all components important to safety must be:

(Several correct answer.)

a)designed according to the old or not applicable standards;

b)designed according to the latest or currently applicable approved standards;

c)of a design proven in previous equivalent applications;

d)of a design not proven in previous equivalent applications;

e)selected to be consistent with the plant reliability goals necessary for safety;

Answers: b), c), e)

What are the fundamental safety functions that must be performed to ensure safety in all operational states and in the case of an accident?

(Several correct answer.)

a)Control of the reactivity;

b)Control of electricity production;

c)Removal of heat from the core;

d)Maintaining heat in the core for a quick start-up after the event;

e)Confinement of radioactive materials and control of operational discharges, as well as limitation of accidental releases.

Answers: a), c), e)

Categories of plant conditions typically cover:

(Several correct answer.)

a)Normal operation;

b)Anticipated operational occurrences;

c)Design basis accidents;

d)Design extension conditions;

Answers: all

The core cooling provided ensures that:

(Several correct answer.)

a)The limiting parameters for the cladding or fuel integrity will not exceed the acceptable value for DBA;

b)The limiting parameters for the cladding or fuel integrity will exceed the acceptable value for DBA;

c)Possible chemical reactions are not limited to an allowable level;

d)Possible chemical reactions are limited to an allowable level;

e)The alterations in the fuel and internal structural alterations will not significantly reduce the effectiveness of the means of emergency core cooling;

f)The cooling of the core will be ensured only during operation on full power;

g)The cooling of the core will be ensured for a sufficient time;

Answers: a), d), e), g)

The emergency core cooling system is designed to permit appropriate periodic inspection to confirm the following:

(Several correct answer.)

a)The necessary leakage of system components;

b)The structural integrity and leak tight integrity of its components;

c)The operability and performance of the active components of the system in normal operation, as far as feasible;

d)The operability of the system as a whole under the conditions specified in the design basis, to the extent practicable;

Answers: b), c), d)

What is the function of the protection system and what is its design purpose?

(Several correct answer.)

a)To initiate automatically the operation of appropriate systems, including, as necessary, the reactor shutdown systems;

b)To initiate automatically the operation of appropriate systems for increasing electricity production;

c)To detect design-basis accidents and to initiate the operation of systems necessary to limit the consequences of such accidents;

d)To detect normal operation and to initiate the operation of systems necessary to limit the consequences of such condition;

e)To be capable of overriding unsafe actions of the control system;

f)To override safe actions of control room personnel;

Answers: a), c), e)

The handling and storage systems for irradiated fuel are designed:

(Several correct answer.)

a)To prevent criticality;

b)To sustain criticality outside the reactor core;

c)To permit adequate heat removal

d)To permit inspection of irradiated fuel;

e)To prevent periodic inspection and testing of components important to safety;

f)To permit the dropping of spent fuel in transit;

g)To prevent unacceptable handling stresses on the fuel elements or fuel assemblies;

h)To provide proper means for radiation protection;

i)To adequately identify individual fuel modules;

Answers: a), c), d), g), h), i)

SAFETY GUIDANCE FOR RESEARCH REACTOR DESIGN

Concern over safety issues regarding research reactors led to development of the Code of Conduct on the Safety of Research Reactors, what arethese safety issues? (Several correct answers!)

a)Aging of research reactors;

b)Production of greenhouse gases;

c)Significant contribution to the safety;

d)Lack of adequate regulatory supervision;

e)The development of nuclear science and technology;

f)Status that has come to be called ‘extended shutdown’;

Answers: a), d), f)

From a list of accidents in nuclear facilities, choose those that occurred in research reactors! (Several correct answers!)

a)11 March 2011 - BWR - Fukushima Daiichi (Japan)

b)12 December 1952 - NRX - Chalk River (Canada)

c)26 April 1986 - RBMK - Chernobyl (Soviet Union)

d)23 September 1983 - RA-2 - Constituyentes (Argentina)

e)28 March 1979 -PWR - TMI2 Pennsylvania (USA)

f)03 January 1961 - SL1 - Idaho Falls (USA)

Answers: b), d), f)