ML23114A076
| ML23114A076 | |
| Person / Time | |
|---|---|
| Site: | University of Missouri-Rolla |
| Issue date: | 04/24/2023 |
| From: | Travis Tate NRC/NRR/DANU/UNPO |
| To: | Taber E Missouri Univ of Science & Technology |
| References | |
| 50-123/23-01 50-123/OL-23 | |
| Download: ML23114A076 (35) | |
Text
April 24, 2023 Mr. Ethan Taber, Reactor Manager Missouri University of Science and Technology Nuclear Reactor Facility 250 West 13th Street Rolla, MO 65409-0630
SUBJECT:
EXAMINATION REPORT NO. 50-123/OL-23-01, MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY
Dear Mr. Taber:
During the week of March 20, 2023, the U.S. Nuclear Regulatory Commission (NRC) administered an operator licensing examination at your Missouri University of Science and Technology Reactor. The examinations were 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) 415-8341 or via email at Amy.Beasten@nrc.gov.
Sincerely, Travis L. Tate, 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. 50-123
Enclosures:
- 1. Examination Report No. 50-123/OL-23-01
- 2. Written examination cc: w/o enclosures to GovDelivery Subscribers Signed by Tate, Travis on 04/25/23
ML23114A076 NRR-079 OFFICE NRR/DANU/UNPO/CE NRR/DANU/UNPO/OLA NRR/DANU/UNPO/BC NAME ABeasten NJones TTate DATE 4/24/2023 4/24/2023 4/25/2023 U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.:
50-123/OL-23-01 FACILITY DOCKET NO.:
50-123 FACILITY LICENSE NO.:
R-79 FACILITY:
Missouri University of Science and Technology EXAMINATION DATES:
March 20-22, 2023 SUBMITTED BY:
_Amy E. Beasten 03/31/2023 Amy E. Beasten, Chief Examiner Date
SUMMARY
During the week of March 20, the NRC administered operator licensing examinations to one Reactor Operator (RO) candidate, one RO written examination retake candidate, and one Senior Reactor Operator-Upgrade (SRO-U) candidate. All candidates passed all applicable portions of the examination.
REPORT DETAILS 1.
Examiner:
Amy Beasten, Chief Examiner, NRC 2.
Results:
RO PASS/FAIL SRO PASS/FAIL TOTAL PASS/FAIL Written 2/0 0/0 2/0 Operating Tests 1/0 1/0 2/0 Overall 2/0 1/0 3/0 3.
Exit Meeting:
Amy Beasten, Reactor Engineer, NRC Ethan Taber, Reactor Manager, Missouri University of Science and Technology Joseph Graham, Facility Director, Missouri University of Science and Technology Alice Skye, Missouri University of Science and Technology Prior to administration of the written examination, 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 examiner met with facility staff representatives to discuss the results. At the conclusion of the meeting, the NRC examiner thanked the facility for their support in the administration of the examination.
Missouri University of Science and Technology Operator Licensing Examination Week of March 20, 2023
U. S. NUCLEAR REGULATORY COMMISSION NON-POWER REACTOR LICENSE EXAMINATION FACILITY:
Missouri University of Science and Technology REACTOR TYPE:
POOL DATE ADMINISTERED:
March 21, 2023 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 is required to pass the examination. Examinations will be picked up three (3) hours after the examination starts.
% OF CATEGORY % OF CANDIDATE'S CATEGORY VALUE TOTAL SCORE VALUE CATEGORY 20.00 33.3 A. REACTOR THEORY, THERMODYNAMICS AND FACILITY OPERATING CHARACTERISTICS 20.00 33.3 B. NORMAL AND EMERGENCY OPERATING PROCEDURES AND RADIOLOGICAL CONTROLS 20.00 33.3 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.
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 or X your choice)
If you change your answer, write your selection in the blank.
A01 a b c d ___
A02 a _____ b _____ c _____ d _____ (0.50 each)
A03 a b c d ___
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 ___
A09 a b c d ___
A11 a _____ b _____ c _____ d _____ (0.25 each)
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 ___
(***** 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 or X your choice)
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 _____ (0.25 each)
B04 a b c d ___
B05 a b c d ___
B06 a _____ b _____ c _____ d _____ (0.25 each)
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 ___
B06 a _____ b _____ c _____ d _____ (0.25 each)
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 ___
(***** 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 or X your choice)
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 _____ (0.25 each)
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 _____ (0.25 each)
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
=
+ [
]
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
te P
P 0
eff K
S S
1
sec 10 1
4
eff SUR 06 26
2 1
1 1
2 1
eff eff K
CR K
CR
2 2
1 1
CR CR 2
1 1
1 eff eff K
K M
1 2
1 1
CR CR K
M eff
)
(
0 10 t
SUR P
P
0 1
P P
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
t e
DR DR
0
2 6
R n
E Ci DR 2
2 2
2 1
1 d
DR d
DR
1 2
1 2
2 2
Peak Peak
T UA H
m T
c m
Q P
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.01
[1.0 point]
Reactor power is initially at 100W. After 120 seconds, reactor power is at 75kW. What is reactor period?
- a. -80s
- b. 16s
- c. 18s
- d. 28s QUESTION A.02
[2.0 points, 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 increases, [Column A] [Column B].
Column A
- a. Fast Fission Factor
- b. Thermal Utilization Factor
- c. Resonance Escape Probability
- d. Thermal Non-Leakage Probability Column B Increases Decreases Stays the same QUESTION A.03
[1.0 point]
Which ONE of the following best describes beta decay?
- a. The emission of a neutrino or antineutrino when an excited state daughter nucleus drops to ground state.
- b. The emission of electrons of nuclear origin rather than orbital origin with the release of a neutrino or antineutrino.
- c. An electron from an inner orbital is combined with a proton in the nucleus to form a neutron with the release of a neutrino or antineutrino.
- d. The emission of a neutrino or antineutrino that interacts with and transfers energy to an inner orbital electron when an excited state daughter nucleus drops to ground state.
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.04
[1.0 point]
The following date was obtained during a reactor fuel load.
Step No. of Elements Detector A (count/sec) 1 0
170 2
2 190 3
5 225 4
9 300 5
13 500 The estimated number of additional elements required to achieve criticality is between:
- a. 8 to 10
- b. 5 to 7
- c. 3 to 4
- d. 1 to 2 QUESTION A.05
[1.0 point]
Which ONE of the following explains the importance of source neutrons?
- a. Source neutrons are essential to achieve and maintain criticality of the reactor.
- b. Source neutrons ensure there is a sufficient neutron population to overcome the effects of fission product poisoning following a shutdown.
- c. Source neutrons are used to lengthen the neutron generation time to ensure the reactor does not go prompt critical.
- d. Source neutrons ensure that there is a sufficient neutron population to provide visible indication of neutron level during start-up and shutdown.
QUESTION A.06
[1.0 point]
Which ONE of the following statements regarding moderator properties is NOT true?
- a. A good moderator has a large absorption cross-section and a small scattering cross-section.
- b. A good moderator has a small absorption cross-section and a large scattering cross-section.
- c. A good moderator has a large energy loss per collision.
- d. A good moderator slows neutrons to reduce the amount of neutron leakage from the core.
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.07
[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. Subcritical reaction of photoneutrons.
- c. Spontaneous fission of Uranium-238.
- d. Production of delayed neutrons.
QUESTION A.08
[1.0 point]
Which ONE of the following has a long-term effect on Keff but is of no consequence during short term and transient operation?
- a. Increase in moderator temperature.
- b. Increase in fuel temperature.
- c. Fuel burnup.
QUESTION A.09
[1.0 point]
The amount of energy produced from a nuclear fission reaction is approximately:
- a. 1000 MeV.
- b. 200 MeV.
- c. 200 keV.
- d. < 1 eV.
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.10
[1.0 point]
Which ONE of the following statements regarding fission product poisoning is NOT true?
- a. Following a reactor shutdown, the concentration of Xe-135 reaches a peak based on the decay of I-135 in the core.
- b. During normal reactor operation, Xe-135 is removed from the core by radioactive decay and neutron absorption.
- c. Following a reactor shutdown, the concentration of Sm-149 reaches a peak because some fission is still occurring in the core.
- d. During normal reactor operation, Sm-149 is removed from the core by neutron absorption.
QUESTION A.11
[1.0 point, 0.25 each]
Match the statements in Column A with the terms in Column B. Choices in Column B may be used once, more than once, or not at all.
Column A
- a. The reactivity change per unit movement of a rod
- b. The total reactivity of worth of the rod at a particular degree of withdrawal.
- c. The ________ curve is s shaped, with a maximum slope at the center of the core.
- d. The _______ curve is bell shaped and has a peak at the center of the core.
Column B Integral Rod Worth Differential Rod Worth QUESTION A.12
[1.0 point]
What is the purpose of a reflector in a reactor core?
- a. A reflector reduces fast neutrons to thermal neutron range.
- b. A reflector increases the ratio of peak flux to the flux at the edge of the core fuel area.
- c. A reflector is used to shield staff working at the base of the reactor from the effects of ionizing radiation while the reactor is operating.
- d. A reflector scatters neutrons back into the core that would otherwise be lost due to leakage.
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.13
[1.0 point]
An experimenter inserts an experiment into the core, and the count rate decreases from 175 cps to 60 cps. Given the initial Keff of the reactor was 0.98, what is the worth of the experiment?
- a. = + 0.02
- b. = - 0.02
- c. = + 0.05
- d. = - 0.05 QUESTION A.14
[1.0 point]
Which ONE of the following best describes reactor power following a reactor scram?
- a. Neutron flux initially drops very quickly, then slowly decays away as neutron population is sustained by the decay of the longest-lived fission product precursor.
- b. Neutron flux drops immediately to near-zero values but is sustained at some small positive value because of fission product poisons accumulation.
- c. Neutron flux decays slowly but constantly because of fission product decay.
- d. Neutron flux drops immediately to negligible values, but power instrumentation on the console continues to register a slightly positive flux rate because of the heat produced by fission product decay.
QUESTION A.15
[1.0 point]
The reactor is slightly supercritical with the following values for each of the factors in the six-factor formula:
Fast Fission Factor = 1.07 Fast non-leakage probability = 0.93 Resonance Escape Probability = 0.91 Thermal non-leakage probability = 0.83 Thermal Utilization Factor = 0.72 Reproduction Factor = 1.92 A control rod is inserted to bring the reactor critical. Assuming all other factors remain unchanged, the new value for the Thermal Utilization Factor is:
- a. 0.722
- b. 0.693
- c. 0.698
- d. 0.798
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.16
[1.0 point]
During a reactor startup, criticality occurred at a lower rod height than the previous startup.
Which ONE of the following explanations could be the reason for the change?
- a. Moderator temperature was higher.
- b. The startup source was removed from the core.
- c. Nuclear Instrumentation drift.
- d. An experiment with positive reactivity was added.
QUESTION A.17
[1.0 point]
Which ONE of the following conditions will decrease the shutdown margin of a reactor?
a.
Insertion of a negative reactivity worth experiment.
b.
Higher moderator temperature (assuming a negative temperature coefficient).
c.
Burnout of a burnable poison.
d.
Fuel depletion.
QUESTION A.18
[1.0 point]
Which ONE of the following best describes the values of Keff and during the power increment when the reactor is increasing power from 10 kW to 100 kW in a prompt criticality?
a.
Keff > 1 and 0 < < eff b.
Keff > 1 and > 1 c.
Keff > 1 and eff < < 1
- d. Keff > 1 and < 1
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.19
[1.0 point]
What ONE of the following is the primary heat transfer mechanism through the cladding of a fuel rod?
a.
Radiation b.
Convection c.
Conduction d.
Mass transfer
(***** END OF CATEGORY A *****)
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.01
[1.0 point]
A sample initially reads 700 mrem/hr. After 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, the sample reads 200 mrem/hr. What is the half-life of the sample?
- a. 4.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />
- b. 3.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />
- c. 2.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />
- d. 1.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> QUESTION B.02
[1.0 point]
A sample reads 175 mrem/hr at a distance of 3 meters from the source. How far away from the source will the reading be 75 mrem/hr?
- a. 7.0 m
- b. 4.6 m
- c. 2.6 m
- d. 1.5 m
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.03
[1.0 point, 0.5 each]
Match the events in Column A with the correct type of Emergency Class in Column B. Options in Column B may be used once, more than once, or not at all.
Column A
- a. Tornado touchdown inside the MS&T campus boundary.
- b. Failure of an experiment capsule with airborne release of Cs-137 powder, resulting in a whole body dose of 100 mrem in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at Pine Street.
- c. Fuel element failure, as indicated by the demineralizer Radiation Area Monitors, where projected radiation levels at Pine Street are estimated to be in excess of 100 mrem/hr for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
- d. Fire affecting the console which cannot be extinguished by operations staff.
Column B Alert Site Area Emergency Unusual Event QUESTION B.04
[1.0 point]
In accordance with SOP 103, Reactor Startup to Low Power, the rate of power increase following instrument turnaround should be limited to:
- a. 50 seconds for a clean core startup and 70 seconds for a hot core startup, as determined by the slope on the Startup Channel recorder.
- b. 70 seconds regardless of core conditions, as determined by the slope on the Startup Channel recorder.
- c. 50 seconds, regardless of core conditions.
- d. 30 seconds, regardless of core conditions.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.05
[1.0 point]
The exposure rate for a point source is 500 mR/hr at a distance of 4 meters. What is the exposure rate at a distance of 8 meters?
a.
31.25 mR/hr b.
125 mR/hr c.
250 mR/hr d.
1000 mR/hr QUESTION B.06
[1.0 point, 0.25 each]
Match the conditions in Column A with the automatic action in Column B. Options in Column B may be used once, more than once, or not at all.
Column A a.
Core Inlet Pool Water Temperature at 140° b.
Reactor Period 5s c.
Basement Experimental Area monitors reading 25 mrem/hr d.
Reactor power at 250 kW Column B Reactor Scram Reactor Rundown Rod Withdrawal Prohibit QUESTION B.07
[1.0 point]
In accordance with SOP 615, when would a Radiation Work Permit be required?
- a. When radiation level is greater than 2 mrem/hr at a distance of 2 feet from the material or part involved.
- b. When there is maintenance work being performed on equipment that is expected to be radioactive.
- c. When handling the neutron source during Radiation Area Monitor calibrations.
- d. When students and/or researchers are handling radioactive samples.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.08
[1.0 point]
When is the presence of an SRO NOT required in accordance with MSTR Technical Specifications?
- a. During restoration of AC power following a power outage.
- b. During control rod inspection.
- c. During relocation of any in-core experiment with a reactivity worth greater than a dollar.
- d. During a hot core reactor startup following a scram.
QUESTION B.09
[1.0 point]
In accordance with SOP 710, which ONE of the following is true regarding experiment movement in the reactor?
- a. All in-core experimental facilities require an Irradiation Request Form
- b. An SRO is required for experiment removal from the core while the reactor is shutdown.
- c. Insertion or removal of any experiment which is not a core component or experimental facility requires approval by the Reactor Manager.
- d. Untried experiments may be approved by the Senior Reactor Operator QUESTION B.10
[1.0 point]
Which ONE of the following would be classified as a High Radiation Area?
- a. 5 mrem/hr at 30 cm
- b. 150 mrem/hr at 30 cm
- c. 500 rad/hr at 1 m
- d. 5.5 G/hr at 1 m
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.11
[1.0 point]
In accordance with SOP 816, all of the following steps are required to be performed for the MSTR Power Calibration, EXCEPT:
- a. Turn on both nitrogen diffusors.
- b. Approximately 4 level readings must be taken at 15 minute intervals prior to reactor startup to determine pool level drop.
- c. Pool level readings may start to be taken after both diffuser pumps have been operating for 15 minutes.
- d. Reactor power should be maintained between 30 and 50 kW for a period of time such that thermal output is between 30 and 50 kW-hr.
QUESTION B.12
[1.0 point]
Which ONE of the following is NOT a requirement of 10 CFR 20?
- a. The total effective dose equivalent to individual members of the public shall not exceed 100 mrem in a year, and 5 mrem in any one hour.
- b. The total effective dose equivalent to occupational adults shall not exceed 5 rems in a year.
- c. Doses received in excess of the annual occupational dose limits are permissible only in exceptional circumstances.
- d. The lens dose equivalent to an occupational adult shall not exceed 15 rem in a year.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.13
[2.0 points, 0.5 point each]
Match the change or facility modification in Column A to the level of authorization required in Column B. Choices in Column B may be used once, more than once, or not at all.
Column A a.
Change the membership composition of the Radiation Safety Committee from five members to four.
b.
Doubling the amount of sample material in a previously approved rabbit facility experiment.
c.
Perform an experiment with 20mg of explosive material in the void tube.
d.
Change the frequency of the shim/safety rod drop times to annually.
Column B Radiation Safety Committee NRC Senior Reactor Operator on Duty Director, Nuclear Reactor QUESTION B.14
[1.0 point]
The Annual Limit on Intake (ALI) is defined as:
a.
The concentration of a given radionuclide in air which, if breathed by an adult worker for a year, would result in a committed effective dose equivalent of 5 rems.
b.
The dose equivalent to organs or tissues that will be received from an intake of radioactive material by an individual during the 50-year period following the intake.
c.
The concentration of a given radionuclide in air which, if breathed by an adult worker for a year, would result in a committed effective dose equivalent of 15 rems.
d.
The derived limit for the amount of radioactive material taken into the body of an adult worker by inhalation or ingestion in a year that would result in a committed effective dose equivalent of 5 rem whole body or 50 rem to any individual organ or tissue.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.15
[1.0 point]
In accordance with SOP 508, all of the following are actions that should be taken if there is a report of a tornado in the vicinity of the reactor, EXCEPT:
- a. Remove magnet power key.
- b. Announce over building PA that all personnel proceed to the designated tornado shelter area.
- c. Scram the reactor.
- d. Evacuate the building per SOP 501.
QUESTION B.16
[1.0 point]
Which ONE of the following conditions is a violation of 10 CFR 55.53, Conditions of Licenses, for licensed reactor operators?
- a. The Senior Reactor Operator on Duty for the days operations actively performed the functions of an SRO for 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> last quarter.
- b. The last requalification operating exam was 12 months ago.
- c. Your last medical exam was 36 months ago.
- d. The new requalification program cycle started 18 months ago.
QUESTION B.17
[1.0 point]
In accordance with SOP 150, a licensed reactor operator shall, in response to a Rundown, perform all of the following actions EXCEPT:
- a. Stop the rundown with the Rundown Reset switch once the alarm condition has cleared and resume normal reactor operations with no further action.
- b. Verify that all rods are inserting and that reactor power is decreasing appropriately.
- c. Record with a right-facing red arrow the time of the rundown and type of rundown in the Permanent Log book.
- d. Notify the SRO on duty.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.18
[1.0 point]
Which ONE of the following statements about surveillance requirements is NOT true?
- a. The control rods shall be visually inspected annually (not to exceed 15 months).
- b. Confinement shall be tested semiannually (not to exceed 7.5 months).
- c. Thermal power shall be experimentally verified annually (not to exceed 15 months).
- d. Ventilation fans and intake/exhaust louvers shall be visually checked quarterly (not to exceed 4 months).
QUESTION B.19
[1.0 point]
Which ONE of the following defines the Emergency Planning Zone for the Missouri S&T reactor facility?
- a. The EPZ is the area enclosed by the walls of the reactor facility.
- b. The EPZ is the outside walls of the reactor confinement building.
- c. The EPZ is the MS&T campus boundary.
- d. The EPZ is the area within a 200-ft radius beyond the walls of the reactor confinement building.
(***** END OF CATEGORY B *****)
Category C: Facility and Radiation Monitoring Systems QUESTION C.01
[1.0 point]
Which ONE of the following statements is true concerning the Missouri S&T regulating rod?
- a. The regulating rod is magnetically coupled to the rod drive extension and will fall freely into the core by gravity on receipt of a scram signal.
- b. The regulating rod is bolted to the rod drive assembly and will not automatically drive in on receipt of a scram signal.
- c. The regulating rod is magnetically coupled to the rod drive extension and will not fall freely into the core by gravity on receipt of a scram signal.
- d. The regulating rod is bolted to the rod drive assembly and will automatically drive in on receipt of a scram signal.
QUESTION C.02
[1.0 point]
The siphon break is located on the ________ and is used to ________.
- a. demineralizer inlet piping; prevent the possibility of pumping the pool down below 16 feet.
- b. demineralizer inlet piping; reduce the radiation level at the pool surface by delaying the rise of N-16.
- c. demineralizer outlet piping; prevent the possibility of pumping the pool down below 16 feet.
- d. demineralizer outlet piping; reduce the radiation level at the pool surface by delaying the rise of N-16.
QUESTION C.03
[1.0 point]
All of the following functions can be bypassed by the SRO EXCEPT:
- a. CR < 2 cps rod withdrawal trip.
- b. Period < 30 s rod withdrawal prohibit.
- c. Core inlet water temperature > 135° F.
- d. High area radiation RAM system rundown.
Category C: Facility and Radiation Monitoring Systems QUESTION C.04
[1.0 point, 0.25 each]
Match the Radiation Area Monitors (RAM) in Column A to the correct automatic actions in Column B. Choices in Column B may be used once, more than once, or not at all.
Column A a.
Demineralizer RAM at 20 mrem/hr b.
Constant Air Monitor (CAM) at 1500cpm c.
Reactor Bridge RAM at 50mrem/hr d.
Basement Experimental Area RAM at 20 mrem/hr Column B Alarm Scram Rundown Building Evacuation QUESTION C.05
[1.0 point]
Which ONE of the following statements is true regarding the operability of the Radiation Area Monitors required by Technical Specifications?
- a. Reactor operation may continue indefinitely with any one RAM inoperable so long as the CAM remains operable.
- b. Operations may continue for up to 1 week with one or more RAM channels inoperable, provided the High Radiation rundown is bypassed.
- c. Operations may continue for up to 1 month with one or more RAM channels inoperable, provided a portable gamma radiation instrument is placed in the same vicinity as the inoperable RAM detector(s) with local audible alarm setpoint of 20 mrem/hr.
- d. Operations may continue for up to 1 week with the reactor bridge RAM inoperable, so long as a portable gamma radiation instrument that can be visually monitored from the control room is placed in the vicinity.
QUESTION C.06
[1.0 point]
Which ONE of the following describes a fuel plate?
Category C: Facility and Radiation Monitoring Systems QUESTION C.07
[1.0 point]
Which ONE of the following statements regarding the Reactor Bridge Monitor is TRUE?
- a. An automatic reactor rundown occurs when radiation levels at or below 20 mrem/hr are detected, and facility ventilation automatically isolates when radiation levels at or below 50 mrem/hr are detected.
- b. An automatic reactor scram occurs when radiation levels at or below 20 mrem/hr are detected, and a building evacuation alarm is automatically initiated when radiation levels at or below 50 mrem/hr are detected.
- c. An automatic reactor rundown occurs when radiation levels at or below 20 mrem/hr are detected, and a reactor scram occurs when radiation levels at or below 50 mrem/hr are detected.
- d. An automatic reactor rundown occurs when radiation levels at or below 20 mrem/hr are detected, and a building evacuation alarm is automatically initiated when radiation levels at or below 50 mrem/hr are detected.
QUESTION C.08
[1.0 point]
With the reactor in automatic mode, what would cause the automatic control to switch back to manual mode?
- b. The shim rods are being moved in bank.
- c. Power level drift of +/- 3% of the set point on the RCS.
- d. The shim rods are indicating Withdraw Limit.
QUESTION C.09
[1.0 point]
Which ONE of the following is the normal mode of cooling for the MSTR core?
- a. Natural convection, where heat is removed through evaporation.
- b. Water from the bottom of the core is passed through the demineralizer, where heat is removed, and returned to the pool.
- c. Water from the bottom of the core is passed through a heat exchanger, where heat is removed, and returned to the pool.
- d. Natural conduction, where heat is removed through evaporation.
Category C: Facility and Radiation Monitoring Systems QUESTION C.10
[1.0 point, 0.25 each]
Match the Nuclear Instrumentation detectors in Column A to the detector type in Column B.
Choices in Column B may be used once, more than once, or not at all.
Column A a.
Startup Channel b.
Log and Linear Power Channel c.
Linear Power Channel d.
Safety Channel Column B Compensated Ion Chamber Uncompensated Ion Chamber Fission Chamber BF3 Filled Chamber QUESTION C.11
[1.0 point]
What is the basis for the core inlet pool water temperature rod withdrawal prohibit?
- a. It prevents the LSSS from being reached by ensuring the moderator can sufficiently cool the fuel during operation.
- b. It provides protection to ensure the demineralizer resins do not degrade.
- c. It provides a layer of protection to ensure the scram setpoint of 140° F is not reached.
- d. It provides a layer of protection that ensures that operations above this point cannot continue without the auxiliary cooling system in operation.
QUESTION C.12
[1.0 point]
While raising rods during a reactor startup, power as indicated by Log Power suddenly drops to 0 from 100kW. As a result:
- a. A rod withdrawal prohibit prevents further rod motion until the RWP alarm is cleared.
- b. The Log and Linear Drawer goes into Not Operate mode, de-energizing the rundown/scram relay, causing a reactor rundown and a reactor scram.
- c. The Log and Linear Drawer goes into Not Operate mode, energizing the rundown/scram relay, causing a reactor rundown and a reactor scram.
- d. There is no effect on the reactor because the signal from this channel is still output to a functional digital chart recorder.
Category C: Facility and Radiation Monitoring Systems QUESTION C.13
[1.0 point]
The gaseous effluent most commonly produced from reactor operation is _______ which is
- a. Rn-222; a naturally occurring isotope.
- b. I-135; produced as a byproduct of fission.
- c. N-16; produced from irradiation of water.
- d. Ar-41; produced from irradiation of air.
QUESTION C.14
[1.0 point]
Which ONE of the following best describes on how the Uncompensated Ion Chamber (UIC) and Compensated Ion Chamber (CIC) operate?
- a. The CIC has two chambers, both of which can sense gamma rays, but only one is coated with Boron-10 for (n,a) reactions. The UIC has only one chamber coated with Boron-10 for (n,a) reactions.
- b. The CIC has only one chamber coated with U-235 for fission reactions. The UIC has two chambers, both of which can sense gamma rays but only one is coated with Boron-10 for (n,a) reactions.
- c. The CIC has two chambers; one is coated with U-235 for fission reactions and the other is coated with Boron-10 for (n,a) reactions. The UIC has only one chamber coated with U-235 for fission reactions.
- d. The CIC has only one chamber coated with Boron-10 for (n,a) reactions. The UIC has two chambers; one is coated with U-235 for fission reactions and the other is coated with Boron-10 for (n,a) reactions.
QUESTION C.15
[1.0 point]
Which ONE of the following best describes why fuel elements may need to be removed from the core during control rod maintenance?
- a. Control rod maintenance is usually done concurrently with fuel shuffle, so the procedure allows for both core manipulations to be performed simultaneously.
- b. To ensure the core is less than 50% critical mass to prevent prompt criticality from occurring
- c. To minimize radiation dose to operators on the reactor pool top.
- d. To comply with core excess requirements.
Category C: Facility and Radiation Monitoring Systems QUESTION C.16
[1.0 point]
Which ONE of the following describes a half fuel element?
- a. Half fuel elements are identical to standard fuel elements, except only nine plates contain fuel, and the other nine plates contain aluminum.
- b. Half fuel elements contain nine aluminum plates and nine fueled plates, because these plates are of higher U-235 enrichment than standard fuel elements.
- c. Half fuel elements contain nine fueled plates surrounding a control rod guide tube.
- d. Half fuel elements are 17 tall.
QUESTION C.17
[1.0 point]
Which ONE of the following statements regarding reflector mode operation is true?
- a. The Technical Specification maximum excess reactivity for the core is 1.5% k/k in the W-mode and 1.0% k/k in the T-mode.
- b. The excess reactivity Technical Specification limit may be waived for operation in the T-mode.
- c. When operating in the T-mode, one or more fuel elements must be removed to ensure the Technical Specification maximum excess reactivity is not exceeded.
- d. Following any change in core configuration, the excess reactivity of the core shall be determined for both the W-mode and the T-mode.
QUESTION C.18
[1.0 point]
In accordance with the MSTR Technical Specifications, which ONE of the following statements regarding pool water quality is NOT true?
- a. Pool water resistivity must be greater than 0.2 M-cm while fuel elements are in the pool.
- b. Pool water resistivity to be measured at least once every 4 weeks during periods when the reactor is operating.
- c. Pool water conductivity shall be measured monthly if the reactor is not operated.
- d. Pool water resistivity measurements can be temporarily exceeded for a period of up to three weeks once every three years as a matter of operational convenience.
Category C: Facility and Radiation Monitoring Systems QUESTION C.19
[1.0 point]
Which ONE of the following statements regarding control rod worth is NOT true?
- a. The total ganged worth of all three safety rods is about 6% k/k.
- b. The rate of change in reactivity for any one safety rod is about 0.02% k/k.
- c. The regulating rod provides approximately 0.5% k/k worth.
- d. The maximum rate of change in reactivity for the regulating rod is 0.014% k/k.
QUESTION C.20
[1.0 point]
Which ONE of the following statements regarding the startup channel is NOT true?
- a. When fully inserted into the core, the startup channel can monitor neutron population up to a reactor power of approximately 1 W.
- b. The startup channel is gradually withdrawn from the core as neutron count rate increases in order to provide an absolute indication of reactor power.
- c. The startup channel provides a signal to prevent control rod movement if neutron count rate is less than 2 cps.
- d. The startup channel may be withdrawn from the core once positive indications register on the linear power channels.
(***** END OF CATEGORY C *****)
((********** END OF EXAM **********))
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics A.01 Answer:
c.
Reference:
DOE Fundamentals Handbook, Volume 2, Module 4, p. 11 P = P0 et/
75kW = 100W e120s/
75,000W = 100W e120s/
750 = e120s/
ln(750) = ln(e120s/)
6.62 = 120s/
= 120/6.62
= 18.1s A.02 Answer:
a.
Stays the same; b.
Increases; c.
Decreases; d. Decreases
Reference:
DOE Fundamentals Handbook, Volume 2, Module 3, p. 2-9.
A.03 Answer:
b.
Reference:
DOE Fundamentals Handbook, Volume 1, Module 1, p. 24-25 A.04 Answer:
b.
Reference:
Burn, R., Introduction to Nuclear Reactor Operations, © 1982, Sec 5.5, p. 5-18 to 5-25 A.05 Answer:
d.
Reference:
DOE Fundamentals Handbook, Volume 1, Module 2, p. 1 A.06 Answer:
a.
Reference:
DOE Fundamentals Handbook, Volume 1, Module 2, p 23-24.
A.07 Answer:
a
Reference:
DOE Fundamentals Handbook, Volume 1, Module 1, p. 61 A.08 Answer:
c
Reference:
Standard NRC question A.09 Answer:
b
Reference:
Lamarsh 3rd, Table 3.6, pg. 88 A.10 Answer:
c.
Reference:
DOE Fundamentals Handbook, Volume 2, Module 3, p. 30-47
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics A.11 Answer:
a.
Differential Rod Worth; b.
Integral Rod Worth; c.Integral Rod Worth; d.
Differential Rod Worth
Reference:
DOE Fundamentals Handbook, Volume 2, Module 3, p. 51-58.
A.12 Answer:
d.
Reference:
DOE Fundamentals Handbook, Volume 2, Module 4, p. 25-34 A.13 Answer:
d.
Reference:
CR1 / CR2 = (1 - Keff2) / (1 - Keff1) 175 / 60 = (1 - Keff2) / (1 - 0.98)
Therefore Keff2 = 0.942
= (Keff2 - Keff1) / (Keff2
- Keff1)
= (0.942 - 0.98) / (0.942
- 0.98)
= - 0.05 A.14 Answer:
a.
Reference:
DOE Fundamentals Handbook, Volume 2, Module 4, p. 31 A.15 Answer:
b.
Reference:
1.07 x 0.91 x 0.93 x 0.83 x 1.92 x 0.72 = 1.039 1 / (1.07 x 0.91 x 0.93 x 0.83 x 1.92) = 0.693 A.16 Answer:
- d.
Reference:
Standard NRC question A.17 Answer:
c.
Reference:
Standard NRC Question A.18 Answer:
c
Reference:
Burns, Section 3.2.1 A.19 Answer:
c
Reference:
DOE Fundamentals Handbook, Module 1, p. 6
(***** END OF CATEGORY A *****)
Category B: Normal/Emergency Operating Procedures and Radiological Controls B.01 Answer:
b.
Reference:
DR = DR0e-t T1/2 = 0.693/; = 0.693/T1/2 200 = 700 e-(0.693/T1/2)(6) 0.2857 = e-(0.693/T1/2)(6) ln(0.2857) = -(0.693/T1/2)(6)
-1.252 = -4.158/T1/2 T1/2 = 3.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> B.02 Answer:
b.
Reference:
DR1*(D1)2 = DR2*(D2)2 ;
175 mrem*(3)2 = 75 mrem(d)2 d = 4.6 m B.03 Answer:
a.
Unusual Event; b.
Alert; c.
Site Area Emergency; d.
Unusual Event
Reference:
Emergency Plan for Missouri S&T Nuclear Reactor Facility, p. 4-1 to 4-3 B.04 Answer:
c.
Reference:
SOP 103 B.05 Answer:
b.
Reference:
l2 = l1D12/d22 l2 = (500 mR/hr)(4m)2 / (8m)2 l2 = 125 mR B.06 Answer:
a.
Rod Withdrawal Prohibit; b. Reactor Scram; c.
Reactor Rundown; d.
Reactor Rundown
Reference:
MSTR Technical Specifications 3.2.1 and 3.2.2 B.07 Answer:
b.
Reference:
SOP 615 B.08 Answer:
a.
Reference:
TS 6.1.3, SOP 308, SOP 302, and SOP 103 B.09 Answer:
c.
Reference:
SOP 710 B.10 Answer:
b.
Reference:
Category B: Normal/Emergency Operating Procedures and Radiological Controls B.11 Answer:
c.
Reference:
SOP 816 B.12 Answer:
a.
Reference:
10 CFR 20.1201, 10 CFR 20.1206, and 10 CFR 20.1301 B.13 Answer:
a.
NRC; b. Director, Nuclear Reactor OR SRO; c.
Radiation Safety Committee; d. NRC
Reference:
MSTR Technical Specifications 6.2, 6.4, and 6.5, SOP 710, TS 3.7.2 B.14 Answer:
d.
Reference:
10 CFR 20 B.15 Answer:
d.
Reference:
SOP 508 B.16 Answer:
c.
Reference:
10 CFR 55.53 B.17 Answer:
a.
Reference:
SOP 150 B.18 Answer:
b.
Reference:
MSTR TS 4.2.1, 4.2.2, 4.4, and 4.5 B.19 Answer:
a.
Reference:
MS&T Emergency Plan
(***** END OF CATEGORY B *****)
C.01 Answer:
b.
Reference:
MST SAR Chapter 4.2.2 C.02 Answer:
a.
Reference:
MST SAR Chapter 5.1 C.03 Answer:
c.
Reference:
MST SAR Chapter 7 C.04 Answer:
a.
Rundown; b. Alarm; c. Building Evacuation; d. Rundown
Reference:
d.
Reference:
c.
Reference:
MST SAR Chapter 4.2 C.07 Answer:
d.
Reference:
c.
Reference:
MST SAR Chapter 7.2.2.7 C.09 Answer:
a.
Reference:
MST SAR Chapter 5.1 C.10 Answer:
a.
Fission Chamber; b. CIC ; c. CIC; d. UIC
Reference:
b.
Reference:
b.
Reference:
MST SAR Chapter 7 C.13 Answer:
d.
Reference:
MST SAR Chapter 11 C.14 Answer:
a.
Category B: Normal/Emergency Operating Procedures and Radiological Controls
Reference:
Standard NRC question C.15 Answer:
b.
Reference:
SOP 302 C.16 Answer:
a.
Reference:
MST SAR Chapter 4.2.1 C.17 Answer:
d.
Reference:
MST TS 3.1 and SOP 111 C.18 Answer:
b.
Reference:
MST TS 3.3 and 4.3 C.19 Answer:
a.
Reference:
b.
Reference:
(***** END OF CATEGORY C *****)
((********** END OF EXAM **********))