Kingdom of Saudi Arabia
Ministry of Higher Education
Majmaah University
Vice rectorate for Academic Affairs
Measurement & Assessments Administration
The Second MidTerm Exams 1435 / 1436 H
College of Science in Zulfi
Program: B. Sc
Course Name: Neutron Physics and Reactor
Course Code: 485
Date: 18 /02/1436
Section: L8
Duration: 1.5 hour
Number of pages: 2
The student's name:……………………………………………
University ID:…………………………………………………..
Examination Guidelines
1- Type your name and university identification number clearly in the space provided.
2- Use blue or black pen in answer and pencil in drawing.
3- Books or notes, papers and publications are not allowed into the examination room.
4- Students are not allowed to get out from the examination room before passing 30
minutes from the beginning of test starting.
Learning Outcomes
The Knowledge
Skills
Interpersonal skills
Cognitive skills
and taking
responsibility
a
b
Communication,
information
technology and
numerical skills
Psychomotor
skills
d
e
c
Grades
Faculty member
…………………………….
Review Committee
Name
Signature
Corrector 1
/…………….
/…………….
/…………….
/…………….
/…………….
Final grade...…../….......
/…………….
Learning
outcome
Question
/…………….
………………..
1
/…………….
………………..
2
/…………….
………………..
3
/…………….
………………..
4
/…………….
………………..
5
Corrector 2
/…………….
Kingdom of Saudi Arabia
Ministry of Higher Education
Majmaah University
Vice rectorate for Academic Affairs
Measurement & Assessments Administration
Exercise 1 (12 Marks)
I) Choose the correct answers:
1) The energy released in the fission of a 235U is about:
a) 200 MeV
b) 200 J
c) 200 eV
d) 0.2 GeV
2) The temperature levels in a nuclear reactor are maintained primarily by the use of:
a) Shielding
b) Coolants
c) Moderators
d) Control rods
3) Heavy water is an example of material that can be used in a nuclear reactor to slow
down neutrons. This material is called:
a) Fuels
b) Moderators
c) Shields
d) Coolants
4) The nuclear reaction in which a heavy nucleus splits into two lightly nuclei is called:
a) Fission
b) Fusion
c) Neutron capture
d) Electron capture
5) If the multiplication factor (k) is equal to 1, the fission chain reaction is called:
a) Supercritical
b) Critical
c) Subcritical
d) reaction at a constant rate
6) The natural uranium is composed essentially from the isotopes:
a)
235
U and 238U
b) 234U and 235U
c) 233U and 239U
Kingdom of Saudi Arabia
Ministry of Higher Education
Majmaah University
Vice rectorate for Academic Affairs
Measurement & Assessments Administration
I) Fill the blanks using the following sentences:
Fuels, to reduce the neutrons leakage, to prevent neutrons from causing biological
harm to operating personnel, fertile material, to prevent to escape of radioactive
fission products, to control the power level.
1- The Control system in a nuclear reactor is used……………………………………
………………………………………………………………………………………..
2- The Fissile material used in a nuclear reactor is called …………………………….
………………………………………………………………………………………….
3- The role of the reflector is…………………………………………………………
………………..………………………………………………………………………
4- The shielding is used……………………………………………………………..
………………………………………………………………………………………..
Kingdom of Saudi Arabia
Ministry of Higher Education
Majmaah University
Vice rectorate for Academic Affairs
Measurement & Assessments Administration
Exercise 2 (8 Marks)
II) Let us consider the following fission reaction:
U 
235
92
1
0
n

Ce 
146
58
Se  a 01n
85
x
1) Calculate the two constants x and a.
2) Calculate the variation of the mass (  m  m f  mi ) that accompanied the
fission.
1
146
Given that : m( 235
92U )  234.99 u , m( 0 n )  1.0086 u , m( 58Ce )  145.878 u
m( 85xSe )  84.903 u .
3) Calculate the released energy  E   m . c 2 (J and MeV) for this reaction.
Given that: (1 u  1.66 10-27 kg , c  3108 m s 1 )
4) Deduce the total energy (J) released by a fission of 1 kg
235
92
U . Given that:
(N A  6.0231023 )
5) Given that, the released energy after the explosion of 1 kg (TNT), is about 4 106 J.
Calculate the equivalent mass of TNT which gives the same energy of the fission of
1 kg
235
92
U.