ML25118A117
| ML25118A117 | |
| Person / Time | |
|---|---|
| Site: | 05000083 |
| Issue date: | 07/03/2025 |
| From: | Michael Brown NRC/NRR/DANU/UNPO |
| To: | Wall D Univ of Florida |
| References | |
| 50-083/25-01 50-083/OL-25 | |
| Download: ML25118A117 (1) | |
Text
Dr. Donald Wall, Facility Director University of Florida Training Reactor P.O. Box 116400 Gainesville, FL 32611-8300
SUBJECT:
EXAMINATION REPORT NO. 50-083/OL-25-01, UNIVERSITY OF FLORIDA
Dear Dr. Wall:
During the week of June 23, 2025, the U.S. Nuclear Regulatory Commission (NRC) administered an operator licensing examination at your University of Florida Training Reactor.
The examination was conducted according to NUREG-1478, "Operator Licensing Examiner Standards for Research and Test Reactors," Revision 2. Examination questions and preliminary findings were discussed with those members of your staff identified in the enclosed report at the conclusion of the examination.
In accordance with Title 10 of the Code of Federal Regulations, Section 2.390, a copy of this letter and the enclosures will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records component of NRC's Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible from the NRC website at http://www.nrc.gov/reading-rm/adams.html. The NRC is forwarding the individual grades to you in a separate letter which will not be released publicly. Should you have any questions concerning this examination, please contact Amy Beasten at 301-415-8347 or via email at Amy.Beasten@nrc.gov.
Sincerely, Tony Brown, Chief Non-Power Production and Utilization Facility Oversight Branch Division of Advanced Reactors and Non-Power Production and Utilization Facilities Office of Nuclear Reactor Regulation Docket No.50-083
Enclosures:
- 1. Examination Report No. 50-083/OL-25-01
- 2. Written examination cc: w/enclosures to GovDelivery Subscribers July 3, 2025 Signed by Brown, Tony on 07/03/25
ML25118A117 NRR-079 OFFICE NRR/DANU/UNPO/CE NRR/DANU/UNPO/OLA NRR/DANU/UNPO/BC NAME ABeasten NJones TBrown DATE 7/3/2025 7/3/2025 7/3/2025 U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.:
50-083/OL 25-01 FACILITY DOCKET NO.:
50-083 FACILITY LICENSE NO.:
R-56 FACILITY:
University of Florida EXAMINATION DATES:
Week of June 23, 2025 SUBMITTED BY:
SUMMARY
During the week of 6/23/2025, operator licensing examinations were administered to one Reactor Operator (RO) and one Senior Reactor Operator-Instant (SRO-I) candidates. Both candidates passed all applicable portions of the examination and test.
REPORT DETAILS 1.
Examiner:
Amy E. Beasten, PhD, Chief Examiner, NRC 2.
Results:
RO PASS/FAIL SRO PASS/FAIL TOTAL PASS/FAIL Written 1/0 1/0 2/0 Operating Tests 1/0 1/0 2/0 Overall 1/0 1/0 2/0 3.
Exit Meeting:
Amy E. Beasten, PhD, Chief Examiner, NRC Brian Shea, UFL Reactor Manager Jyothier Nimmagadda, Senior Reactor Operator Prior to administration of the written exam, based on facility comments, adjustments were accepted. Comments provided corrections and additional clarity to questions/answers and identified where changes were appropriate based on current facility conditions. Upon completion of all operator licensing examinations, the NRC examiners met with facility staff representatives to discuss the results and observations. At the conclusion of the meeting, the NRC examiners thanked the facility for their support in the administration of the examination.
6/26/2025 Amy E. Beasten, Chief Examiner Date University of Florida Operator Licensing Examination Week of June 23, 2025
U. S. NUCLEAR REGULATORY COMMISSION NON-POWER REACTOR LICENSE EXAMINATION FACILITY:
University of Florida REACTOR TYPE:
Argonaut DATE ADMINISTERED:
CANDIDATE:
INSTRUCTIONS TO CANDIDATE:
Answers are to be written on the Answer sheet provided. Attach all Answer sheets to the examination. Point values are indicated in parentheses for each question. A 70% in each category and a 70% overall are required to pass the examination. Examinations will be picked up three (3) hours after the examination starts.
CATEGORY VALUE
% OF TOTAL CANDIDATE'S SCORE
% OF CATEGORY VALUE CATEGORY 20.00 33.0 A. REACTOR THEORY, THERMODYNAMICS, AND FACILITY OPERATING CHARACTERISTICS 20.00 33.0 B. NORMAL AND EMERGENCY OPERATING PROCEDURES AND RADIOLOGICAL CONTROLS 20.00 33.0 C. FACILITY AND RADIATION MONITORING SYSTEMS 60.00 TOTALS FINAL GRADE All work done on this examination is my own. I have neither given nor received aid.
Candidate's Signature
NRC RULES AND GUIDELINES FOR LICENSE EXAMINATIONS During the administration of this examination the following rules apply:
1.
Cheating on the examination means an automatic denial of your application and could result in more severe penalties.
2.
After the examination has been completed, you must sign the statement on the cover sheet indicating that the work is your own and you have neither received nor given assistance in completing the examination. This must be done after you complete the examination.
3.
Restroom trips are to be limited and only one candidate at a time may leave. You must avoid all contacts with anyone outside the examination room to avoid even the appearance or possibility of cheating.
4.
Use black ink or dark pencil only to facilitate legible reproductions.
5.
Print your name in the blank provided in the upper right-hand corner of the examination cover sheet and each Answer sheet.
6.
Mark your Answers on the Answer sheet provided. USE ONLY THE PAPER PROVIDED AND DO NOT WRITE ON THE BACK SIDE OF THE PAGE.
7.
The point value for each question is indicated in [brackets] after the question.
8.
If the intent of a question is unclear, ask questions of the examiner only.
9.
When turning in your examination, assemble the completed examination with examination questions, examination aids and Answer sheets. In addition turn in all scrap paper.
10.
Ensure all information you wish to have evaluated as part of your Answer is on your Answer sheet. Scrap paper will be disposed of immediately following the examination.
11.
To pass the examination you must achieve a grade of 70 percent or greater in each category and a 70 percent overall.
12.
There is a time limit of three (3) hours for completion of the examination.
Category A: Reactor Theory, Thermodynamics, & Facility Operating Characteristics A N S W E R S H E E T Multiple Choice (Circle your choice, or write on the line)
If you change your answer, write your selection in the blank.
A01 a b c d ___
A02 a b c d ___
A03 a_________ b_________ c_________ d_________
(0.50 each)
A04 a b c d ___
A05 a b c d ___
A06 a b c d ___
A07 a b c d ___
A08 a b c d ___
A09 a b c d ___
A10 a b c d ___
A11 a b c d ___
A12 a b c d ___
A13 a b c d ___
A14 a b c d ___
A15 a b c d ___
A16 a b c d ___
A17 a b c d ___
A18 a b c d ___
A19 a b c d ___
A20 a b c d ___
(***** END OF CATEGORY A *****)
Category B: Normal/Emergency Operating Procedures and Radiological Controls A N S W E R S H E E T Multiple Choice (Circle your choice, or write on the line)
If you change your answer, write your selection in the blank.
B01 a b c d ___
B02 a b c d ___
B03 a b c d ___
B04 a b c d ___
B05 a_________ b_________ c_________ d_________
(0.25 each)
B06 a b c d ___
B07 a b c d ___
B08 a b c d ___
B09 a b c d ___
B10 a b c d ___
B11 a b c d ___
B12 a b c d ___
B13 a b c d ___
B14 a b c d ___
B15 a b c d ___
B16 a b c d ___
B17 a b c d ___
B18 a b c d ___
B19 a b c d ___
B20 a_________ b_________ c_________ d_________
(0.25 each)
(***** END OF CATEGORY B *****)
Category C: Facility and Radiation Monitoring Systems A N S W E R S H E E T Multiple Choice (Circle your choice, or write on the line)
If you change your answer, write your selection in the blank.
C01 a b c d ___
C02 a b c d ___
C03 a b c d ___
C04 a b c d ___
C05 a b c d ___
C06 a b c d ___
C07 a b c d ___
C08 a b c d ___
C09 a b c d ___
C10 a b c d ___
C11 a b c d ___
C12 a b c d ___
C13 a b c d ___
C14 a b c d ___
C15 a b c d ___
C16 a b c d ___
C17 a b c d ___
C18 a b c d ___
C19 a b c d ___
C20 a b c d ___
(***** END OF CATEGORY C *****)
(********** END OF EXAMINATION **********)
EQUATION SHEET
=
+
DR - Rem, Ci - curies, E - Mev, R - feet 1 Curie = 3.7 x 1010 dis/sec 1 kg = 2.21 lb 1 Horsepower = 2.54 x 103 BTU/hr 1 Mw = 3.41 x 106 BTU/hr 1 BTU = 778 ft-lb
°F = 9/5 °C + 32 1 gal (H2O) 8 lb
°C = 5/9 (°F - 32) cP = 1.0 BTU/hr/lb/°F cp = 1 cal/sec/gm/°C
2 2
max
P 1
sec 1.0
eff
T UA H
m T
c m
Q P
sec 10 1
4
2 1
1 1
2 1
eff eff K
CR K
CR
eff SUR 06 26
te P
P 0
eff K
S S
1
2 2
1 1
CR CR
0 1
P P
1 2
1 1
CR CR K
M eff
)
(
0 10 t
SUR P
P 2
1 1
1 eff eff K
K M
eff eff K
K SDM
1 2
1 1
2 eff eff eff eff K
K K
K
693
.0 2
1 T
eff eff K
K 1
2 2
2 2
1 1
d DR d
DR
t e
DR DR
0
1 2
1 2
2 2
Peak Peak
2 6
R n
E Ci DR
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.01
[1.0 point]
Which ONE of the following statements best describes transient equilibrium of radioactive decay?
- a. This occurs when the parent nuclide has a short half-life compared to the daughter nuclide, resulting in both decaying at the same rate.
- b. This occurs when the parent nuclide has a long half-life compared to the daughter nuclide, resulting in both decaying at the same rate.
c.
This occurs when the daughter nuclide is decaying at the same rate it is being produced.
- d. This occurs when the parent nuclide has an extremely long half-life such that the final stable element in the chain has a constantly increasing number of atoms.
QUESTION A.02
[1.0 point]
What is the reactor period if = 0.0065 and = 0.008?
- a. - 1.86 seconds
- b. - 5.34 seconds c.
- 7.13 seconds
- d. - 9.19 seconds QUESTION A.03
[2.00 point, 0.50 each]
Match the terms in Column A with the result in Column B to complete the following statements.
Answers in Column B may be used once, more than once, or not at all:
As moderator temperature DECREASES, [Column A] [Column B].
Column A
- a. Resonance Escape Probability b.
Fast Fission Factor c.
Thermal Non-Leakage Probability d.
Thermal Utilization Factor Column B
- 1. Increases
- 2. Decreases
- 3. Stays the same
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.04
[1.0 point]
Which ONE of the following isotopes is an example of a fertile material?
a.
U-235 b.
U-238 c.
U-233 d.
Pu-239 QUESTION A.05
[1.0 point]
A reactor is overmoderated when a/an ______ in the moderator-to-fuel ratio decreases keff because of a/an _________.
a.
increase; increase in resonance absorption.
b.
increase; decrease in the thermal utilization factor.
c.
decrease; increase in the thermal utilization factor.
d.
decrease; increase in resonance absorption.
QUESTION A.06
[1.0 point]
Which ONE of the following statements best describes the infinite multiplication factor, k?
a.
The ratio of the number of neutrons produced by fission in one generation to the number of neutrons lost through absorption in the preceding generation.
b.
The ratio of the number of neutrons produced by fission in one generation to the number of neutrons lost through leakage in the preceding generation.
c.
The ratio of the number of neutrons produced by fission in one generation to the number of neutrons lost through absorption and leakage in the preceding generation.
d.
The ratio of the number of neutrons produced by fission in one generation to the number of neutrons absorbed in the fuel in the preceding generation.
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.07
[1.0 point]
Which ONE of the following statements BEST describes the Liquid-Drop Model of a nucleus?
a.
The density of a nucleus remains constant regardless of atomic number, much like a drop of water has a constant density regardless of how large it gets.
b.
The energy required to displace all the subatomic particles is comparable to the energy required to disperse all water molecules in a drop of water.
c.
The size of an atoms nucleus compared to the size of the whole atom is comparable to the size of a drop of water compared to an ocean.
d.
The travel path of an atom through a material is the same as flow path of a single drop of water in a larger body.
QUESTION A.08
[1.0 point]
What is the remaining power following the prompt drop in the reactor power when a rod worth of 0.82 K/K is rapidly inserted into a critical reactor? Assume eff = 0.0065 a.
14.4%
b.
11.6%
c.
1.43%
d.
0.15%
QUESTION A.09
[1.0 point]
Which ONE of the following is the principal source of heat in the reactor after a shutdown from extended operation at full power?
a.
Decay of fission fragments.
b.
Xe-135 peaking due to burnout.
c.
Spontaneous fission of U-235.
d.
Continued production of delayed neutrons.
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.10
[1.0 point]
Which ONE of the following best describes the effect of Xe-135 on normal reactor operation?
a.
Xe-135 has a large mass which causes increased scattering collisions, slowing more neutrons to thermal energies as the concentration builds up over time.
b.
Xe-135 is inert and therefore has no impact on reactor operations.
c.
Xe-135 has a large thermal neutron absorption cross-section, which causes large removal of thermal neutrons from the core, causing negative reactivity addition.
d.
When Xe-135 is formed, kinetic energy in the form of heat is released, causing increases in moderator temperature and subsequently decreases in reactor power over the course of normal reactor operation.
QUESTION A.11
[1.0 point]
A reactor is shut down by 3.25% k/k. If control rods are withdrawn until the count rate increases by a factor of 6, and the reactor is still subcritical, what is the new Keff?
a.
0.987 b.
0.995 c.
1.006 d.
1.012 QUESTION A.12
[1.0 point]
Which ONE of the following decay chains correctly describes the production and removal of Xe-135 from the reactor?
a.
Te135 - + Cs135 - + Xe135 -+ I135 - + Ba135 b.
I135 - + Te135 - + Xe135 -+ Cs135 - + Ba135 c.
Te135 - + I135 - + Xe135 -+ Ba135 - + Cs135 d.
Te135 - + I135 - + Xe135 -+ Cs135 - + Ba135
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.13
[1.0 point]
Which ONE of the following statements regarding fission with thermal neutrons is true?
a.
U-238 fissions with thermal neutrons because the binding energy released by the absorption of a neutron is greater than the critical energy for fission.
b.
U-238 fissions with thermal neutrons because the binding energy released by the absorption of a neutron is less than the critical energy for fission.
c.
U-235 fissions with thermal neutrons because the binding energy released by the absorption of a neutron is greater than the critical energy for fission.
d.
U-235 fissions with thermal neutrons because the binding energy released by the absorption of a neutron is less than the critical energy for fission.
QUESTION A.14
[1.0 point]
All of the following factors in the Six Factor Formula are impacted by increasing the number of fuel elements in the core EXCEPT:
a.
Fast Non-Leakage Probability b.
Reproduction Factor c.
Fast Fission Factor d.
Thermal Non-Leakage Probability QUESTION A.15
[1.0 point]
Which ONE of the following best describes the difference between prompt and delayed neutrons?
a.
Prompt neutrons are produced from spontaneous fission of U-235 in the fuel, and delayed neutrons are the result of fission in U-238.
b.
Prompt neutrons are produced immediately and directly from the fission event and delayed neutrons are produced immediately following the first beta decay of fission fragments.
c.
Prompt neutrons are responsible for the ability to control the rate at which power can rise in the reactor and delayed neutrons are responsible for the rate at which a reactor can be shut down.
d.
Prompt neutrons ensure there is a sufficient neutron population to overcome the effects of fission product poisoning following a shutdown and delayed neutrons are responsible for lengthening the neutron generation time to ensure the reactor does not go prompt critical.
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.16
[1.0 point]
Following a reactor scram, the period meter will indicate _______ because ________.
a.
-120 seconds; the fuel temperature coefficient adds negative reactivity as a result of the decrease in fuel temperature following a scram.
b.
-80 seconds; of the decay constant for the longest-lived neutron precursor.
c.
0 seconds; the reactor is subcritical and reactor power is decreasing.
d.
Slightly positive; the neutron source is providing detectable neutron count rate to keep the reactor slightly supercritical.
QUESTION A.17
[1.0 point]
Given Isotope 92U235, f = 537 barns, c = 156 barns, determine the fraction of thermal neutrons absorbed in U-235 by fission. Note: f = fission cross section, c = capture cross section a.
0.84 b.
0.77 c.
0.31 d.
0.23 QUESTION A.18
[1.0 point]
Which ONE of the following statements is NOT a characteristic of an effective moderator?
a.
Large scattering cross section.
b.
Small absorption cross section.
c.
Large energy loss per collision.
d.
Low thermal conductivity.
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.19
[1.0 point]
Which ONE of the following statements best describes resonance elastic scattering?
a.
A neutron interacts with a nucleus to form a compound nucleus, which is excited and emits a gamma while the incident neutron remains in the ground-state nucleus.
b.
A neutron is absorbed by a nucleus to form a compound nucleus which then emits a neutron of lower kinetic energy, leaving the original nucleus in an excited state.
c.
A neutron interacts with a nucleus and short range nuclear forces scatter the neutron when it gets close to the nucleus.
d.
A neutron is absorbed to form a compound nucleus and is then re-emitted such that kinetic energy is conserved and the nucleus returns to ground state.
(***** END OF CATEGORY A *****)
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.01
[1.0 point]
In accordance with the UFL Emergency Plan, which ONE of the following statements best defines the Operations Boundary?
a.
The area from which emergency directions are given, e.g. the Decontamination Room and Room 108 in the Nuclear Sciences Building.
b.
The reactor building, annex, and west fenced lot (as necessary).
c.
The area beyond the main UF campus, which may depend on the distance at which Protective Action Guides could be exceeded.
d.
The line about the main UF campus.
QUESTION B.02
[1.0 point]
In accordance with SOP-A.3, Operation at Power, all of the following conditions must be met to use the automatic flux control system EXCEPT:
a.
All control blades shall be < 750 units.
b.
Power shall be > 1 W.
c.
Reactor power shall be within 20% of the % demand setting.
d.
Reactor power must be at or near steady-state power.
QUESTION B.03
[1.0 point]
In accordance with UFL Technical Specifications, all of the following conditions would be permissible during reactor operations EXCEPT:
a.
Excess reactivity measured at 780 pcm b.
Reactor coolant bulk inlet temperature at 110 °C.
c.
Reactor coolant system resistivity measured at 0.6 M-cm over a 4-hour period.
d.
Shield tank level 10 below the top of the tank.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.04
[1.0 point]
If a sample was removed from the pneumatic transfer system emitting a dose rate of 310 mrem/hr at 15 cm, how long would it need to decay before storing it would require posting it as a radiation area? Assuming the half-life of the specimen is 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.
a.
0.95 hr b.
3.21 hr c.
5.17 hr d.
7.88 hr QUESTION B.05
[1.0 point, 0.25 each]
In accordance with SOP A.5, Reactor Experiments, match the experiment type in Column A with the Class of experiment in Column B. Options in Column B may be used once, more than once, or not at all.
Column A a.
Doubly encapsulated rabbit tube experiments containing a small amount of mercury.
b.
A series of gold foil experiments that are being run as a continuation of a former students thesis work.
c.
Removal of stepped shield plugs in the thermal column to accommodate a large experimental apparatus.
d.
Vertical port experiments containing a small amount of TRISO fuel pellets Column B 1.
Class I 2.
Class II 3.
Class III QUESTION B.06
[1.0 point]
In accordance with SOP D.2, Radiation Work Permit, which ONE of the following statements best describes when a Level II RWP is required?
a.
Insertion or removal of a vertical port experiment containing I-131.
b.
Replacement of the core vent absolute filter.
c.
A half-day thermal column experiment external to the reactor involving samples which must be manually inserted and removed during reactor operation.
d.
During handling of irradiated fuel for fuel inspection, or fuel loading evolutions.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.07
[1.0 point]
What is the dose rate at 1 foot, given 80% of the decay of an 8 Curie source results in emission of a 450 keV gamma?
a.
1.73 R/hr b.
9.34 R/hr c.
15.79 R/hr d.
17.28 R/hr QUESTION B.08
[1.0 point]
In accordance with SOP A.2, Reactor Startup, at which point does the reactor change from MODE 3 to MODE 2?
a.
When reactor power is at or greater than 1%.
b.
When the dump valve is energized and the primary coolant pump is started.
c.
When Control Blade 2 is withdrawn 570 units.
d.
When the reactor becomes subcritical by < 760 pcm.
QUESTION B.09
[1.0 point]
Which ONE of the following scenarios would NOT be required to undergo the 10 CFR 50.59 process?
a.
Amending the Safety Analysis Report to reflect use of stainless steel clad fuel elements.
b.
Adding a step to the control rod reactivity worth measurement procedure to allow the operator to try a new method for determining reactivity worths.
c.
Amending a procedure to increase the frequency of a Technical Specification required surveillance from annual to semi-annual.
d.
Replacing the core vent fan with the same model fan.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.10
[1.0 point]
In accordance with SOP A.7, Control Blade Reactivity Worth Measurements, which ONE of the following statements best describes the Blade Swap method for determining differential and integral blade worths?
a.
The worth of all blades at a steady-state critical condition is determined, then the reactor is shutdown and the blade being measured is replaced with a dummy blade. The reactor is brought to the same steady-state critical condition and the difference in reactivity is determined.
b.
The blade swap method is based upon incremental movement of the blade being measured while compensating with incremental movement of a reference blade to maintain steady-state critical condition.
c.
The worth of the blade is measured by withdrawing the blade to achieve a constant positive period from 60 to 100 seconds and determining the positive reactivity change from the In-Hour equation.
d.
The blade being measured is dropped from a steady-state critical position and the decay rate of the neutron flux immediately following the blade drop is determined.
QUESTION B.11
[1.0 point]
The radiation from an unshielded source is 500 mrem/hr. A lead sheet of 15 mm thickness is inserted and the radiation level drops to 10 mrem/hr. What is the half-value-layer (HVL) of lead?
a.
2.66 mm b.
4.63 mm c.
15.7 mm d.
26.7 mm QUESTION B.12
[1.0 point]
In accordance with 10 CFR 20, which ONE of the following statements best describes the Annual Limit on Intake (ALI)?
a.
Derived limit for the amount of radioactive material taken into the body of an adult worker by inhalation or ingestion in a year.
b.
The concentration of a given radionuclide in air which, if breathed by the reference man for a working year of 2,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> under conditions of light work results in one yearly intake limit.
c.
The dose equivalent to organs or tissues of reference (T) that will be received from an intake of radioactive material by an individual during the 50-year period following the intake.
d.
The sum of the effective dose equivalent for external exposures and the committed effective dose equivalent for internal exposures.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.13
[1.0 point]
In accordance with SOP B.2, Fire, in the event of a fire, the Reactor Operator should take all of the following actions EXCEPT:
a.
Scram and secure reactor.
b.
De-energize electrical power to the console, regardless of where the fire is.
c.
Secure reactor cell air handler.
d.
Attempt to extinguish, if safe to do so.
QUESTION B.14
[1.0 point]
A radiation worker is conducting work in the reactor bay and inadvertently drops a sample releasing Plutonium-239 into the air. They breathe in the equivalent of an internal dose of 100 rem. If the weighting factor of bone is 0.01, which ONE of the following statements is TRUE?
a.
The individual violated both Organ Dose and TEDE limits.
b.
The individual did not violate either Organ Dose or TEDE dose limits.
c.
The individual violated their TEDE limit but not their Organ Dose limit.
d.
The individual violated their Organ Dose limit but not their TEDE limit.
QUESTION B.15
[1.0 point]
In accordance with UFL Technical Specifications, a Senior Reactor Operator is required to be present at the facility for all of the following events EXCEPT:
a.
Receipt and movement of new fuel into the spent fuel pit.
b.
Reactor restart following a loss of power to the facility.
c.
During movement of concrete block shielding over the top of the core in Mode 5.
d.
Fuel shuffle within the core.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.16
[1.0 point]
The radiation level in the control room is 225 mrem/hour, and the operator is in the control room for 37 minutes. How much dose will the operator receive?
a.
13.88 mRem b.
64.29 mRem c.
110.65 mRem d.
138.75 mRem QUESTION B. 17
[1.0 point]
In accordance with SOP A.2, Reactor Startup, which ONE of the following actions should the Reactor Operator take if the 1-Watt critical position is 30 units above the normal cold, xenon-free critical position?
a.
Notify the Senior Reactor Operator for authorization to continue and establish and record a new critical position for the regulating blade.
b.
Record the critical blade positions and proceed to SOP A.3, Reactor Operation at Power, to continue with reactor operation.
c.
Immediately scram the reactor.
d.
Remove the PuBe source and continue with SOP A.3, Reactor Operation at Power.
QUESTION B.18
[1.0 point]
In accordance with UFL Technical Specifications, all of the following surveillances are required annually EXCEPT:
a.
Shutdown margin verification.
b.
Control blade reactivity insertion rate verification.
c.
Reactor coolant bulk inlet temperature channel test.
d.
Reactor coolant flow channel calibration.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.19
[1.0 point]
In accordance with SOP C.2, Fuel Loading, all of the following statements are true EXCEPT:
a.
Fuel loading is considered an experiment where fuel is added incrementally to achieve a critical condition.
b.
All irradiated fuel to be loaded into the core must be visually inspected and cleaned two months prior to core loading.
c.
Fuel loading must be accomplished with water out of the core and all control blades fully inserted.
d.
Irradiated fuel that is stored in the spent fuel pit may not be reloaded into a new core.
QUESTION B.20
[1.0 point]
Match the event in Column A with the UFL Emergency Plan classification in Column B.
Options in Column B may be used once, more than once, or not at all.
Column A a.
Fire on the reactor console that can be manually extinguished.
b.
Indications of fuel cladding blistering identified during fuel inspection.
c.
Hurricane warning in effect for Gainesville.
d.
Receipt of credible bomb threat affecting reactor facility Column B 1.
Class 0 2.
Notification of Unusual Event 3.
Alert
(***** END OF CATEGORY B *****)
Category C: Facility and Radiation Monitoring Systems QUESTION C.01
[1.0 point]
In accordance with the UFL Safety Analysis Report, all of the following statements regarding the Core Vent System are true EXCEPT:
a.
During normal operations, air from the core vent fan is diluted with outside air prior to release from the stack.
b.
An automatic reactor trip will occur if gamma activity in the vent flow exceeds a predetermined level.
c.
Loss of electrical power to the reactor vent motor will cause an automatic reactor trip.
d.
The vent damper cannot be opened unless the dilution fan is energized.
QUESTION C.02
[1.0 point]
In accordance with the UFL Safety Analysis Report, the Shield Water Tank may be used for which ONE of the following purposes?
a.
Core flux mapping.
b.
High flux experiments.
c.
Shielding experiments.
d.
Short-duration beam experiments.
QUESTION C.03
[1.0 point]
Which ONE of the following statements best describes the core assembly of the UFTR?
a.
Six fuel boxes containing a total of 22 full fuel assemblies, 1 partial assembly, and 1 dummy assembly, with each fuel assembly consisting of 14 fuel plates of aluminum clad U3Si2-Al alloy meat.
b.
Four fuel boxes containing a total of 22 fuel assemblies, 1 partial assembly, and 1 dummy assembly with each fuel assembly consisting of 14 fuel plates of aluminum clad U3Si2-Al alloy meat.
c.
Six fuel boxes containing a total of 24 fuel assemblies, with each fuel assembly consisting of 18 fuel plates of aluminum clad U3Si2-Al alloy meat.
d.
Four fuel boxes containing a total of 24 fuel assemblies, with each fuel assembly consisting of 16 fuel plates of aluminum clad U3Si2-Al alloy meat.
Category C: Facility and Radiation Monitoring Systems QUESTION C.04
[1.0 point]
Which ONE of the following statements best describes the purpose of the rupture disk?
a.
The rupture disk is intended to burst at approximately 0.2 psi above normal confinement system pressure to minimize the effects of overpressure on the reactor cell.
b.
The rupture disk is designed to burst when equipment pit water level is greater than 1 inch above the equipment pit floor to prevent additional leakage from the primary coolant system.
c.
The rupture disk is designed to burst at approximately 2 psi above normal operating system pressure to minimize the effects of a pressure excursion.
d.
The rupture disk is intended to burst prevent water hammer in the primary coolant system by rupturing if water flow increases 20 gpm above normal.
QUESTION C.05
[1.0 point]
Which ONE of the following statements best describes the design of Reactor Power Channel 1?
a.
It consists of a compensated ion chamber and an uncompensated ion chamber.
b.
It consists of a B-10 proportional counter and a fission chamber.
c.
It consists of a BF3 proportional counter and a fission chamber.
d.
It consists of a compensated ion chamber and a fission chamber.
QUESTION C.06
[1.0 point]
Which ONE of the following statements best describes the operation of the UFL radiation area monitors?
a.
A plastic scintillator detector that emits varying intensities of light based on the energy of the radioactive particle incident on the detector.
b.
A Geiger Mueller detector that uses a bimetallic film to discriminate between high and low energy betas and gammas to produce a dose rate.
c.
A Geiger Mueller detector attenuated to a proportional energy through use of a Cesium source to produce a dose rate.
d.
An ion chamber specifically utilizing boron to distinguish between neutrons and gammas to provide an effective biological dose rate.
Category C: Facility and Radiation Monitoring Systems QUESTION C.07
[1.0 point]
In the event of a loss of power to the facility, all of the following equipment is powered by the diesel electric generator EXCEPT:
a.
Radiation monitors b.
Primary coolant system dump valve c.
Reactor power channels QUESTION C.08
[1.0 point]
All of the following conditions would result in a Blade-trip EXCEPT:
a.
Secondary flow below 60 gpm on the well water system while operating at 20 kW.
b.
Shield tank water level 18 below the top of the tank.
c.
No return flow on the primary coolant system.
d.
Loss of A.C. power.
QUESTION C.09
[1.0 point]
In accordance with the UFL Technical Specifications, reactor cell ventilation systems are required to be operable in all of the following circumstances EXCEPT:
a.
Operations in Mode 3.
b.
Fuel movement.
c.
Movement of concrete block shielding over the top of the core in Mode 5.
d.
Movement of irradiated fueled experiments.
QUESTION C.10
[1.0 point]
A gaseous effluent that could be produced at UFL from normal reactor operation is
_______ which is _______.
a.
H-3; produced from irradiation of water.
b.
F-19; produced from irradiation of air.
c.
Na-24; produced from irradiation of core components.
d.
Ar-41; produced from irradiation of air.
Category C: Facility and Radiation Monitoring Systems QUESTION C.11
[1.0 point]
In accordance with the UFL Safety Analysis Report, which ONE of the following statements best describes the secondary coolant scram?
a.
In city water mode, a reduction in flow results in a series of warning lights before initiating a scram approximately 10 seconds after the low flow pre-set limit is reached.
b.
In both city water and well modes of cooling, the scram signal is enabled at all reactor power levels.
c.
In well water mode, a reduction in flow results in a warning light before initiating a scram approximately 10 seconds after the low flow pre-set limit is reached.
d.
In well water mode, the scram signal is immediately initiated when the low flow pre-set limit is reached.
QUESTION C.12
[1.0 point]
Which ONE of the following statements best describes the importance of maintaining a negative pressure in the reactor cell compared to the rest of the UFL facility?
a.
This ensures the reactor is isolated such that environmental controls such as temperature and humidity are maintained within a narrow band to prevent degradation of reactor protection system components.
b.
This minimizes the accumulation of radioactive gases in the reactor cell by drawing air from the cell through the exhaust stack during emergency operation only.
c.
This ensures that during normal and emergency conditions, all air remains in the reactor cell and does not leak out to the environment.
d.
This ensures that all air leakage is into the reactor cell, which controls the release of radioactive effluents to the environment through the stack.
QUESTION C.13
[1.0 point]
In accordance with UFL Technical Specifications, the Safety Limit is established at
________ in order to ___________.
a.
530°C; prevent buildup of gases inside the element due to dissociation of the fuel.
b.
530°C; prevent fuel damage due to blister formation.
c.
986°C; prevent the coolant from boiling away.
d.
986°C; prevent the aluminum cladding from melting.
Category C: Facility and Radiation Monitoring Systems QUESTION C.14
[1.0 point]
In accordance with UFL Technical Specifications, on the primary coolant line, all of the following conditions would cause a reactor scram EXCEPT:
a.
Primary coolant flow at 39 gpm.
b.
Coolant bulk outlet temperature at 122°F.
c.
Reactor coolant level less than 2 inches above the fuel.
d.
Resistivity indicating 0.4 M-cm.
QUESTION C.15
[1.0 point]
Which ONE of the following statements best describes how control blade position is indicated in the control room?
a.
Inches withdrawn.
b.
Percent blade width withdrawn.
c.
Units withdrawn.
d.
Degrees withdrawn.
QUESTION C.16
[1.0 point]
Which ONE of the following options correctly describes how primary coolant inlet temperature is measured?
a.
A thermocouple detects changes in primary inlet temperature by measuring the voltage difference between two wires of dissimilar metals.
b.
A thermistor detects changes in primary inlet temperature by using a thermally sensitive resistor that exhibits a continuous, small, incremental change in resistance correlated to variations in temperature.
c.
A resistance temperature detector detects changes in primary inlet temperature by measuring changes in resistance to the flow of electricity resulting from changes in temperature of the resistive metal element.
d.
A semiconductor-based temperature sensor detects changes in primary inlet temperature by utilizing two identical diodes with temperature-sensitive voltage vs current characteristics that are used to monitor changes in temperature.
Category C: Facility and Radiation Monitoring Systems QUESTION C.17
[1.0 point]
Which ONE of the following statements regarding Radiation Monitoring is most correct?
a.
If the stack radiation monitor becomes inoperable, reactor operations may not continue.
b.
If a required radiation monitor is inoperable, operations may continue for up to 7 days if it is replaced with a portable instrument within 60 minutes.
c.
The air particulate detector is not a detector required for operation since it is moveable.
d.
The stack radiation monitor is interlocked with the core vent damper so that it closes when the alarm setpoint is reached.
QUESTION C.18
[1.0 point]
Reactor Power Channel 2 has all of the following functions EXCEPT:
a.
Period trip at 3 seconds.
b.
Loss of detector high voltage trip.
c.
Overpower trip at 110% of rated power.
d.
Automatic blade control.
QUESTION C.19
[1.0 point]
In accordance with the UFL Safety Analysis Report, which ONE of the following statements best describes the purpose of having the fuel boxes elevated?
a.
It minimizes the radiological effects of activation products from other core components when working on the reactor top.
b.
It disrupts the flow path of N-16 to the surface to allow more time for it to decay.
c.
It minimizes the amount of coolant and shielding needed for the reactor.
d.
It ensures that events causing a loss of primary coolant flow result in the water gravity draining from the fuel boxes to shut down the reactor.
Category C: Facility and Radiation Monitoring Systems QUESTION C.20
[1.0 point]
In accordance with the UFL Safety Analysis Report, which ONE of the following statements best describes the control blade assembly?
a.
A reduction gear train motor with an electrically energized magnetic clutch.
b.
A reversible DC motor with a chain/gear system with an electromagnet.
c.
A rack-and-pinion drive with an electrically energized magnetic clutch.
d.
An electric stepper motor with a linear drive.
(***** END OF CATEGORY C *****)
(********** END OF EXAMINATION **********)
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics A.01 Answer:
b.
Reference:
DOE Fundamentals Handbook, Volume 1, Module 1, p. 40-41 A.02 Answer:
a.
Reference:
=
+
= 1 104 0.008 + 0.0065 0.008 0.1 0.008 T = 0.0125 - 1.875 T = - 1.86 A.03 Answer:
- a. 1 (Increases); b. 3 (Stays the same); c. 1 (Increases); d. 2 (Decreases)
Reference:
DOE Fundamentals Handbook, Volume 2, Module 3, p. 16 A.04 Answer:
b.
Reference:
DOE Fundamentals Handbook, Volume 1, Module 1, p. 52 A.05 Answer:
b.
Reference:
DOE Fundamentals Handbook, Vol. 2, Module 3, p. 28 A.06 Answer:
a.
Reference:
DOE Fundamentals Handbook, Vol. 1, Module 3, p. 15 A.07 Answer:
a.
Reference:
Lamarsh, Introduction to Nuclear Engineering, p. 11 A.08 Answer:
c.
Reference:
P1 P0 =
eff (1 p) eff p P1/P0 = (0.0065 x (1+0.82)) / (0.0065+0.82)
P1/P0 = 0.0143 P1/P0 = 1.43%
A.09 Answer:
a.
Reference:
DOE Fundamentals Handbook, Vol. 1, Module 1, p. 61 A.10 Answer:
c.
Reference:
DOE Fundamentals Handbook, Volume 2, p. 34
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics A.11 Answer:
b.
Reference:
Burn, Introduction to Nuclear Reactor Operations, Section 5.7.10, page 5-33.
SCR1 = S / (1 - K1eff) AND SCR2 = S / (1 - K2eff) 1 = 3.25% K/K 1 = 0.0325 K/K K1eff = 1 / (1 - 1)
K1eff = 1 / (1 - 0.0325)
K1eff = 0.9675 SCR2/SCR1 = S * (1 - 0.9675) / S * (1 - K2eff) 6 = 0.0325 / (1 - K2eff) 1 - K2eff = 0.00542 K2eff = 1 - 0.00542 K2eff = 0.995 A.12 Answer:
d.
Reference:
Burn, Introduction to Nuclear Reactor Operations, p. 8-6.
A.13 Answer:
c.
Reference:
DOE Fundamentals Handbook, Vol. 1, Module 1, p. 55 A.14 Answer:
b.
Reference:
DOE Fundamentals Handbook, Vol. 2, Module 3, p. 3 A.15 Answer:
b.
Reference:
DOE Fundamentals Handbook, Vol. 1, Module 2, p. 29 A.16 Answer:
b.
Reference:
DOE Fundamentals Handbook, Vol. 1, Module 2, p. 7 A.17 Answer:
b.
Reference:
Burn, Introduction to Nuclear Reactor Operations, Section 3.2, page 3-2.
U-235 Fission Capture = f /(f + c) 537/(537+156) = 0.7 A.18 Answer:
d.
Reference:
DOE Fundamentals Handbook, Vol. 1, Module 2, p. 23 A.19 Answer:
d.
Reference:
DOE Fundamentals Handbook, Vol. 1, Module 1, p. 44-45
(***** END OF CATEGORY A *****)
Category B: Normal/Emergency Operating Procedures and Radiological Controls B.01 Answer:
b.
Reference:
UFL Emergency Plan, 2.0 B.02 Answer:
a.
Reference:
SOP-A.3, Operation at Power B.03 Answer:
b.
Reference:
UFL Technical Specifications 3.1, 3.2.2, 3.3.2, 3.9.1 B.04 Answer:
d.
Reference:
DR1d12 = DR2d22 310 * (15)2 = DR2 * (30)2 31000 = DR2
- 900 DR2 = 77.5 D = D0
- e-t ; where D0 = 77.5 mrem/hr; D = 5 mrem/hr; and = ln(2)/2 hr 5 = 77.5
- e-(ln(2)/2)t 0.065 = e-(ln(2)/2)t ln(0.065) = ln(e-(ln(2)/2)t)
-2.74 = -(ln(2)/2.5)t
-2.74 = -0.347t t = 7.88 hr B.05 Answer:
- a. 3 (III); b. 1 (I); c. 2 (II); d. 3 (III)
Reference:
SOP A.5, Reactor Experiments B.06 Answer:
c.
Reference:
SOP D.2, Radiation Work Permit B.07 Answer:
d.
Reference:
6 Cen = R/hr at 1 ft (6
- 8 Ci) x (0.8
- 0.450) 17.28 R/hr at 1 ft B.08 Answer:
d.
Reference:
SOP A.2, Reactor Startup B.09 Answer:
d.
Reference:
Category B: Normal/Emergency Operating Procedures and Radiological Controls B.10 Answer:
b.
Reference:
SOP A.7, Control Blade Reactivity Worth Measurements B.11 Answer:
a.
Reference:
DR = DR0*e-X Find :
10 = 500*e -*15 0.02 = e-*15 ln(0.02) = ln(e-*15)
-3.91 = -*15
= 0.261 If insertion of an HVL (thickness of lead), the original intensity will be reduced by half.
Find X:
1 = 2* e-0.261*X 0.5 = e-0.261*X ln(0.5) = ln(e-0.261*X)
-0.693 = -0.261*X X= 2.66 mm B.12 Answer:
a.
Reference:
10 CFR 20.1003 B.13 Answer:
b.
Reference:
SOP-B.2, Fire B.14 Answer:
d.
Reference:
DDE = 0 CDE = 100 rem with a Tissue Weighting factor of 0.01 Organ Dose = DDE+CDE = 0+100 rem. 10 CFR 20 limit is 50 rem.
TEDE = DDE + CEDE = 0+(100*0.01) = 1 rem. 10 CFR 20 limit is 5 rem.
B.15 Answer:
a.
Reference:
UFL Technical Specifications 6.1.3 B.16 Answer:
d.
Reference:
Dose = DR*T 225 mRem/hr/60 minutes = 3.75 mRem/min 3.75 mRem/min
- 37 min = 138.75 mRem B.17 Answer:
a.
Reference:
SOP A.2, Reactor Startup
Category B: Normal/Emergency Operating Procedures and Radiological Controls B.18 Answer:
c.
Reference:
UFL Technical Specifications 3.1, 3.2.1, 3.2.2, 3.2.3 B.19 Answer:
d.
Reference:
SOP C.2, Fuel Loading B.20 Answer:
- a. 1 (Class 0); b. 3 (Alert); c. 1 (Class 0) or 2 (Unusual Event); d. 2 (Unusual Event)
Reference:
UFL Emergency Plan, Table 5.1
(***** END OF CATEGORY B *****)
Category C: Facility and Radiation Monitoring Systems C.01 Answer:
b.
Reference:
UFL SAR 9.1.2 C.02 Answer:
c.
Reference:
UFL SAR 10.2.4 C.03 Answer:
a.
Reference:
UFL SAR 4.1.1 C.04 Answer:
c.
Reference:
UFL SAR 5.2 C.05 Answer:
b.
Reference:
UFL SAR 7.1.3.1.1 C.06 Answer:
c.
Reference:
UFL SAR 7.6 C.07 Answer:
b.
Reference:
UFL SAR 8.2 C.08 Answer:
d.
Reference:
UFL SAR 7.3.1 C.09 Answer:
a.
Reference:
UFL Technical Specifications 3.5 C.10 Answer:
d.
Reference:
Standard NRC question C.11 Answer:
c.
Reference:
UFL SAR 7.1.3.2.2 C.12 Answer:
d.
Reference:
UFL SAR 9.1.2 C.13 Answer:
b.
Reference:
UFL Technical Specifications 2.1
Category C: Facility and Radiation Monitoring Systems C.14 Answer:
d.
Reference:
UFL Technical Specifications 3.2.2 and 3.3.2 C.15 Answer:
c.
Reference:
UFL SAR 7.2.1 C.16 Answer:
a.
Reference:
UFL SAR 7.1.3.2.1 C.17 Answer:
b.
Reference:
UFL Technical Specifications 3.7.1 C.18 Answer:
a.
Reference:
UFL SAR 7.1.3.1.2 C.19 Answer:
d.
Reference:
UFL SAR 5.2 C.20 Answer:
a.
Reference:
UFL SAR 4.2.2
(***** END OF CATEGORY C *****)
(********** END OF EXAMINATION **********)