ML24141A007
| ML24141A007 | |
| Person / Time | |
|---|---|
| Site: | Oregon State University |
| Issue date: | 07/03/2024 |
| From: | Travis Tate NRC/NRR/DANU/UNPO |
| To: | Reese S Oregon State University, TRIGA Reactor |
| References | |
| 50-243/24-01 50-243/OL-24 | |
| Download: ML24141A007 (30) | |
Text
Dr. Steven R. Reese, Director Oregon State University 100 Radiation Center Corvallis, OR 97331-5903
SUBJECT:
EXAMINATION REPORT NO. 50-243/OL-24-01, OREGON STATE UNIVERSITY
Dear Dr. Reese:
During the week of June 10, 2024, the U.S. Nuclear Regulatory Commission (NRC) administered an operator licensing examination at your Oregon State University research 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 301-415-8341 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. 50-243
Enclosures:
- 1. Examination Report No. 50-243/OL-24-01
- 2. Written examination cc: w/enclosures to GovDelivery Subscribers July 3, 2024 Signed by Tate, Travis on 07/03/24
ML24141A007 NRR-079 OFFICE NRR/DANU/UNPO/CE NRR/DANU/UNPO/OLA NRR/DANU/UNPO/BC NAME ABeasten NJones TTate DATE 7/3/2024 7/3/2024 7/3/2024 U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.:
50-243/OL 24-01 FACILITY DOCKET NO.:
50-243 FACILITY LICENSE NO.:
R-106 FACILITY:
Oregon State University EXAMINATION DATES:
Week of June 10, 2024 SUBMITTED BY:
SUMMARY
During the week of June 10, 2024, operator licensing exams were administered to one Senior Reactor Operator-Instant (SRO-I), one Senior Reactor Operator-Upgrade (SRO-U), and five Reactor Operator (RO) candidates. All candidates passed all applicable portions of both the written and operating exams.
REPORT DETAILS 1.
Examiner:
Amy E. Beasten, PhD, Chief Examiner, NRC 2.
Results:
RO PASS/FAIL SRO PASS/FAIL TOTAL PASS/FAIL Written 5/0 1/0 6/0 Operating Tests 5/0 2/0 2/0 Overall 5/0 2/0 7/0 3.
Exit Meeting:
Travis Tate, Branch Chief, NRC Amy E. Beasten, PhD, Chief Examiner, NRC Tuan Le, Reactor Engineer, NRC Dr. Steven Reese, Director Robert Strickland, Assistant Director/Reactor Administrator Celia Oney, Reactor Supervisor 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.
6/28/2024 Amy E. Beasten, PhD, Chief Examiner Date Oregon State University Operator Licensing Examination Week of June 10, 2024
U. S. NUCLEAR REGULATORY COMMISSION NON-POWER REACTOR LICENSE EXAMINATION FACILITY:
Oregon State University Reactor REACTOR TYPE:
TRIGA DATE ADMINISTERED:
June 13, 2024 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
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 ___
A03 a ________ b ________ c ________ d ________ (0.25 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 ________ (0.33 each)
A15 a ________ b ________ c ________ d ________ (0.50 each)
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 ___
B04 a b c d ___
B05 a ________ b ________ c ________ d ________ (0.25 each)
B06 a b c d ___
B07 a ________ b ________ c ________ d ________ (0.25 each)
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 ________ (0.25 each)
B13 a b c d ___
B14 a b c d ___
B15 a ________ b ________ c ________ d ________ (0.25 each)
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 ___
(***** END OF CATEGORY B *****)
Category C: Plant 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 ___
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 **********)
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.
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 a particle ejection reaction?
- a. A neutron is absorbed by a target, creating a compound nucleus. The compound nucleus decays to ground state by emitting a gamma.
- b. A neutron is absorbed by a target, creating a compound nucleus. The compound nucleus splits into two similarly sized nuclei.
c.
A neutron is absorbed by a target, creating a compound nucleus. The compound nucleus immediately emits a particle, like an alpha or a proton.
- d. A neutron is absorbed by a target, creating a compound nucleus. The compound nucleus splits into two nuclei of dissimilar sizes and emits a charged particle.
QUESTION A.02
[1.0 point]
All of the following factors affect the resonance escape probability EXCEPT:
- a. Concentration of Xe-135.
- b. Moderator-to-fuel ratio.
c.
Moderator temperature.
- d. Enrichment of U-235.
QUESTION A.03
[1.0 point, 0.25 each]
Match the isotope in Column A with the type of material in Column B. Options in Column B may be used once, more than once, or not at all.
Column A a.
U-238 b.
U-233 c.
Th-232 d.
U-235 Column B 1.
Fissionable 2.
Fertile 3.
Fissile
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.04
[1.0 point]
The figure below shows a trace of reactor period as a function of time. Which ONE of the following describes reactor power from point B to point D?
a.
Reactor power is increasing, then decreasing, then stable.
b.
Reactor power is continually increasing.
c.
Reactor power is constant.
d.
Reactor power is increasing, then stable.
QUESTION A.05
[1.0 point]
How much of the TOTAL energy produced per fission of a thermal neutron with U-235 is released as gamma energy?
a.
167 MeV b.
21 MeV c.
15 MeV d.
10 MeV QUESTION A.06
[1.0 point]
The moderator temperature coefficient for a reactor is -0.00075 k/k/°F. What is the total reactivity change caused by a temperature decrease of 15°F?
a.
0.0113 k/k b.
0.0205 k/k c.
0.0315 k/k d.
0.0615 k/k
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.07
[1.0 point]
As control rods are withdrawn during subcritical multiplication, which ONE of the following statements is TRUE?
a.
keff approaches 1, M approaches 0, and 1/M approaches.
b.
keff approaches 0, M approaches 1, and 1/M approaches.
c.
keff approaches 1, M approaches, and 1/M approaches 0.
d.
keff approaches 0, M approaches, and 1/M approaches 1.
QUESTION A.08
[1.0 point]
Which ONE of the following statements best explains the importance of source neutrons?
a.
Source neutrons ensure that the shutdown neutron population is sufficient to provide visible indication of neutron level during startup.
b.
Source neutrons control the rate at which power can initially rise in a reactor from shutdown to initial criticality.
c.
Source neutrons lengthen the neutron generation time to ensure adequate control over the increases in reactor power.
d.
Source neutrons ensure that there is a sufficient neutron population in the core to overcome the effects of fission product poison following a reactor shutdown.
QUESTION A.09
[1.0 point]
Which ONE of the following statements best describes the spectrum hardening effect of the negative fuel temperature coefficient for the OSTR TRIGA reactor?
a.
As fuel temperature rises, the density of the fuel increases. This hardens the energy spectrum, increasing the number of thermal neutrons that may be absorbed in the fuel.
b.
As fuel temperature rises, increases in the vibration of the lattice structures occur. This hardens the energy spectrum, increasing the resonance absorption of thermal neutrons in the fuel.
c.
As fuel temperature rises, the density of the fuel decreases. This causes an increase in distance a neutron must travel before slowing down, resulting in an increase in leakage from the core.
d.
As fuel temperature rises, U-238 burns out in the fuel. This causes spectrum hardening of the energy range of neutrons that may be absorbed in U-235.
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.10
[1.0 point]
The current count rate is 250 cps. An experimenter inserts an experiment into the core and the count rate increases to 470 cps. If the initial keff was 0.395, what is the worth of the experiment?
a.
- 0.129 b.
- 0.227 c.
+ 1.057 d.
+ 1.739 QUESTION A.11
[1.0 point]
Which ONE of the following decay chains correctly describes the production and removal of Xe-135 from the reactor?
a.
I135 - + Te135 - + Xe135 -+ Cs135 - + Ba135 b.
Te135 - + I135 - + Xe135 -+ Ba135 - + Cs135 c.
Ba135 - + Te135 - + Xe135 -+ I135 - + Cs135 d.
Te135 - + I135 - + Xe135 -+ Cs135 - + Ba135 QUESTION A.12
[1.0 point]
While bringing the reactor critical, which ONE of the following describes how a subcritical reactor responds to equal insertions of positive reactivity?
a.
Each reactivity insertion results in a smaller increase in neutron flux, resulting in a decreased stabilization time.
b.
Each reactivity insertion results in a smaller increase in neutron flux, resulting in an increased stabilization time.
c.
Each reactivity insertion results in a larger increase in neutron flux, resulting in an increased stabilization time.
d.
Each reactivity insertion results in a larger increase in neutron flux, resulting in a decreased stabilization time.
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.13
[1.0 point]
Given a reactor period of 32 seconds, approximately how long will it take for power to triple?
a.
35.2 seconds b.
68.3 seconds c.
72.9 seconds d.
96.0 seconds QUESTION A.14
[1.0 point, 0.33 each]
Match the coefficient in Column A with the definition in Column B.
Column A a.
b.
eff c.
Column B 1.
Fraction of neutrons at thermal energies which were born as delayed neutrons.
2.
Weighted average of total delayed neutron fractions of the individual fuel types.
3.
Fraction of all fission neutrons born as delayed neutrons QUESTION A.15
[2.0 point, 0.50 each]
Match the factor in Column A with the effect in Column B to complete the following statement. (Note that 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.
Fast Non-Leakage Probability d.
Reproduction Factor Column B 1.
Stays the same 2.
Decreases 3.
Increases
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.16
[1.0 point]
Which ONE of the following statements best describes the OSTR moderator temperature coefficient?
a.
The OSTR is under-moderated, meaning an increase in the moderator-to-fuel ratio decreases keff as a result of a decrease in the thermal utilization factor. This results in a negative coefficient of reactivity.
b.
The OSTR is under-moderated, meaning a decrease in the moderator-to-fuel ratio decreases keff as a result of increased resonance absorptions. This results in a negative coefficient of reactivity.
c.
The OSTR is over-moderated, meaning an increase in the moderator-to-fuel ratio decreases keff as a result of a decrease in the thermal utilization factor. This results in a positive coefficient of reactivity.
d.
The OSTR is over-moderated, meaning a decrease in the moderator-to-fuel ratio decreases keff as a result of increased resonance absorptions. This results in a positive coefficient of reactivity.
QUESTION A.17
[1.0 point]
Which ONE of the following best describes the difference between moderators and reflectors?
a.
Reflectors scatter fast neutrons and moderators absorb thermal neutrons.
b.
Reflectors scatter neutrons to decrease leakage from the core and moderators thermalize neutrons.
c.
Reflectors thermalize neutrons and moderators scatter neutrons to decrease leakage from the core.
d.
Reflectors scatter thermal neutrons and moderators scatter fast neutrons.
QUESTION A.18
[1.0 point]
During a reactor startup, criticality occurred at a LOWER rod height than the last startup.
Which ONE of the following reasons could be the cause?
a.
The accumulation of fission product poisons as a result of previous operation.
b.
An experiment with negative reactivity was added to the core.
c.
An experiment with positive reactivity was added to the core.
d.
Fuel temperature increased.
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.19
[1.0 point]
Which ONE of the following best describes the difference between delayed and prompt neutrons?
a.
Delayed neutrons are produced as a result of fission in U-238 and prompt neutrons are produced from spontaneous fission of U-235 in the fuel.
b.
Delayed neutrons are produced as a result of installed neutron sources and prompt neutrons are produced as a result of fission in U-238.
c.
Delayed neutrons are produced from spontaneous fission of fission fragments and prompt neutrons are produced directly from fission.
d.
Delayed neutrons are produced immediately following the first beta decay of fission fragments and prompt neutrons are produced immediately and directly from fission.
(***** END OF CATEGORY A *****)
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.01
[1.0 point]
In accordance with the OSTR Emergency Plan, in the event of an emergency which ONE of the following individuals may assume the role of Emergency Coordinator?
a.
Radiation Center Director b.
Licensed Reactor Operator c.
Licensed Senior Reactor Operator d.
Senior Health Physicist QUESTION B.02
[1.0 point]
In accordance with OSTROP 1, Annunciator Procedures, all of the following could be probable causes of the Continuous Air Monitor (CAM) High Activity alarm EXCEPT:
a.
Fuel cladding breach.
b.
Loss of electrical power.
c.
Argon gas from in-core facilities that exhaust during the power ascension.
d.
In-core sample failure.
QUESTION B.03
[1.0 point]
What is the dose rate at 1 foot, given 75% of the decay of a 3 Curie source results in emission of a 150 keV gamma?
a.
20.3 R/hr b.
10.2 R/hr c.
7.18 R/hr d.
2.03 R/hr
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.04
[1.0 point]
During a normal reactor startup, when the UP pushbutton is depressed on the transient rod, the transient rod does not move. In accordance with OSTROP 4, Reactor Operation Procedures, which ONE of the following steps would NOT have caused the transient rod to remain on the bottom if it had been missed?
a.
Loudspeaker announcement was not made that reactor startup is commencing.
b.
Condition causing rod withdrawal prohibit has not been cleared.
c.
Transient Rod Fire button has not been depressed.
d.
Transient rod carrier was not positioned to down.
QUESTION B.05
[1.0 point, 0.25 each]
Match the Technical Specification required surveillance in Column A with the surveillance frequency in Column B. Options in Column B may be used once, more than once, or not at all.
Column A a.
Inspection and cleaning of transient rod drive cylinder b.
Channel test of ability of reactor bay confinement ventilation system to secure c.
Channel calibration of radiation monitoring systems d.
Channel check of reactor tank water level monitor Column B 1.
Monthly 2.
Semi-annually 3.
Annually 4.
Biennially QUESTION B.06
[1.0 point]
In accordance with 10 CFR 20, individual members of the public are limited to an annual dose limit of:
a.
2 mrem b.
100 mrem c.
500 mrem d.
5 rem
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.07
[1.0 point, 0.25 each]
Match the definition in Column A with the term in Column B. Options in Column B may be used once, more than once, or not at all.
Column A a.
The dose equivalent at a tissue depth of 1 cm.
b.
The derived limit for the amount of radioactive material taken into the body by inhalation or ingestion in a year.
c.
The sum of the effective dose equivalent for external exposures and the committed effective dose equivalent for internal exposure.
d.
The dose equivalent to organs or tissues that will be received from an intake of radioactive material by an individual over a 50-year period following intake.
Column B 1.
Annual Limit on Intake (ALI) 2.
Committed Dose Equivalent (CDE) 3.
Deep-Dose Equivalent (Hd) 4.
Total Effective Dose Equivalent (TEDE)
QUESTION B.08
[1.0 point]
In accordance with OSTROP 11, Fuel Element Handling Procedures, for normal in-core fuel handling, all of the following statements are true EXCEPT:
a.
All Technical Specification required radiation monitoring systems must be operating.
b.
The reactor is shut down.
c.
The ventilation system must be in isolation.
d.
All external reactor bay doors shall be closed.
QUESTION B.09
[1.0 point]
In accordance with OSTROP 1, Annunciator Response Procedures, which ONE of the following actions is NOT an action to take if the Reactor Tank Low Water Level alarm comes in?
a.
Ensure ventilation is isolated.
b.
Shut down the reactor.
c.
Check for indications of increasing radiation.
d.
Secure the primary and demineralizer pumps.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.10
[1.0 point]
The radiation from an unshielded source is 250 mrem/hr. A 15-mm thick lead sheet is inserted and the radiation level drops to 100 mrem/hr. What is the half-value-layer (HVL) of lead?
a.
1.13 mm b.
6.11 mm c.
11.3 mm d.
61.1 mm QUESTION B.11
[1.0 point]
In accordance with the OSTR Emergency Plan, which ONE of the following responsibilities does NOT fall under the purview of the Emergency Coordinator?
a.
Re-entry into the reactor facility if evacuation was required.
b.
Notify offsite entities, such as the NRC and DOE, of event classification.
c.
Classify the event.
d.
Emergency event termination.
QUESTION B.12
[1.0 point, 0.25 each]
Match the experiment in Column A with the experiment classification in Column B. Options in Column B may be used once, more than once, or not at all.
Column A a.
Beam tube irradiation of 12.5 mg TNT-equivalent b.
Gold-foil irradiation in the rotating specimen rack c.
Flux mapping following core reload d.
Subcritical multiplication experiments for new operator trainees Column B 1.
Class A 2.
Class B 3.
Class C
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.13
[1.0 point]
Which ONE of the following statements would NOT meet the requirements of 10 CFR 55, Operators Licenses?
a.
Your last requalification written exam was 13 months ago.
b.
Your last medical exam was performed 12 months ago.
c.
Last quarter, you were the licensed operator for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
d.
Your last requalification operations exam was 15 months ago.
QUESTION B.14
[1.0 point]
In accordance with the OSTR Emergency Plan, which ONE of the following events would be classified as a Notification of Unusual Event?
a.
Personnel injury resulting in offsite medical response.
b.
Continuous Air Monitor alarms without known cause.
c.
Violent protest outside the reactor building.
d.
Loss of reactor tank water that cannot be made up by normal water make up systems, where more than 80% of the inventory has been lost.
QUESTION B.15
[1.0 point, 0.25 each]
Match the function in Column A with the definition in Column B. Options in Column B may be used once, more than once, or not at all.
Column A a.
Verification of correct indications on the Wide Range Log Power Channel by raising reactor power to a known setpoint b.
Comparison of the Safety Channel power indications with the Percent Power channel indications c.
Comparison of current Percent Power channel indications with Percent Power channel indications at the same reactor power levels during previous operations d.
Adjustment of the Safety Channel indications following performance of the thermal power calibration to correct for acceptable instrument drift Column B 1.
Channel Check 2.
Channel Test 3.
Channel Calibration
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.16
[1.0 point]
All of the following are true statements regarding OSTR Technical Specification surveillance requirements EXCEPT:
a.
Surveillances that are deferred during reactor shutdown must be performed prior to reactor startup unless reactor operation is required for performance of the surveillance.
b.
If a surveillance that is deferred during a reactor shutdown requires reactor operation is for performance of the surveillance, the surveillance must be performed within one month of restart.
c.
Scheduled surveillances that cannot be performed with the reactor operating may be deferred until a planned shutdown.
d.
Most surveillance requirements may be deferred during reactor shutdown.
QUESTION B.17
[1.0 point]
In accordance with OSTR Technical Specifications, the Radiation Operations Committee (ROC) has all of the following review and approval functions EXCEPT:
a.
Review of proposed changes to the Safety Analysis Report.
b.
Review of procedural violations having safety significance.
c.
Review of new procedures.
d.
Review of administrative changes to existing procedures.
QUESTION B.18
[1.0 point]
In accordance with OSTROP 8, Reactor Power Calibration Procedures, which ONE of the following actions is NOT to be taken when preparing to conduct this surveillance?
a.
Ensure primary pump is running to maintain water temperature below 40 °C.
b.
Ensure that the starting pool tank temperature is 25 °C.
c.
Turn off secondary pump and cooling tower fan.
d.
Ensure the reactor bay is empty and no one is on the reactor top for the duration of the 1 MW run.
Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.19
[1.0 point]
According to OSTR Technical Specifications, which ONE of the following conditions is NOT permissible while the reactor is operating?
a.
Pool tank water temperature is 47 °C.
b.
Control rod scram times are 1.75 seconds.
c.
The core excess reactivity is $7.75.
d.
The maximum reactivity insertion for pulse mode operation was $2.15.
QUESTION B.20
[1.0 point]
In accordance with OSTROP 12, Control Rod Maintenance, Removal, and Replacement Procedures, following removal of fuel from the reactor core, why must the most reactive rod be withdrawn to the full out position?
a.
Verification of rod withdrawal and insertion rates.
b.
The rod must be fully withdrawn while the transient rod is removed from the core to ensure the reactor can be scrammed if it goes critical unexpectedly.
c.
This is the first rod that is always removed for visual inspection and the rod must be withdrawn to facilitate removal from the core.
d.
Verification that readings on wide range log-linear channels reflect a subcritical condition.
(***** END OF CATEGORY B *****)
Category C: Facility and Radiation Monitoring Systems QUESTION C.01
[1.0 point]
All of the following statements are functions of the primary coolant cleanup system EXCEPT:
a.
Removes soluble particulate matter from the primary coolant, which may help to reduce radioactivity in the coolant.
b.
Maintains a low conductivity of the primary coolant to help minimize corrosion of reactor components.
c.
Maintains optical clarity of the primary coolant.
d.
Minimizes dose rate from N-16 at the surface by acting as a holdup tank to allow N-16 to decay.
QUESTION C.02
[1.0 point]
Which ONE of the following best describes how the wide range log channel operates?
a.
The wide range log channel is a fission chamber lined with B-10. Neutrons fission with the B-10 to produce alpha particles which ionize the fill gas. Gammas also ionize the fill gas.
The combined signal provides an indication of reactor power.
b.
The wide range log channel is a fission chamber lined with highly enriched U-238. Neutrons interact with the U-238 to produce fission, which ionize the fill gas. Gammas also ionize the fill gas. At low powers, the circuitry uses a pulse height discriminator to differentiate the neutrons from the gammas to provide an indication of reactor power.
c.
The wide range log channel is a fission chamber lined with highly enriched U-235. Neutrons interact with the U-235 to produce fission fragments, which ionize the fill gas. Gammas also ionize the fill gas. At low powers, the circuitry uses a pulse height discriminator to differentiate the neutrons from the gammas to provide an indication of reactor power.
d.
The wide range log channel is a dual fission chamber, with one chamber filled with highly enriched U-235 and the other filled with an inert gas. Neutrons fission with the U-235 to produce alpha particles which ionize the gas. Gammas also ionize the fill gases in both chambers. The gamma signal is subtracted from the neutron signal to provide an indication of reactor power.
QUESTION C.03
[1.0 point]
Which ONE of the following isotopes is commonly produced from beam port operation?
a.
N-16 as a result of irradiation of water filling the beam ports.
b.
Ar-41 as a result of irradiation of air filling the beam ports.
c.
Na-24 as a result of irradiation of the aluminum construction materials.
d.
Co-60 as a result of the irradiation of the stainless-steel construction materials.
Category C: Facility and Radiation Monitoring Systems QUESTION C.04
[1.0 point]
Which ONE of the following best describes the regulating rod drive assembly?
a.
The regulating rod drive assembly is an electromechanical drive with a rack-and-pinion gear system, a two-phase reversible motor, and a magnetic rod coupler.
b.
The regulating rod drive assembly is an electromechanical drive with a single-acting pneumatic cylinder and air driven piston.
c.
The regulating rod drive assembly is an electromechanical drive, with rack-and-pinion gear system, a stepper motor and reduction gear, and a magnetic rod coupler.
d.
The regulating rod drive assembly is an electromechanical drive, with a reduction gear system, a two-phase reversible motor, and a magnetic rod coupler.
QUESTION C.05
[1.0 point]
Which ONE of the following describes the type of detector used for the reactor top Continuous Air Monitor?
a.
Geiger-Mueller tube b.
Thin-film scintillation detector c.
Na-I scintillation detector d.
Gaseous scintillation detector QUESTION C.06
[1.0 point]
Which ONE of the following statements correctly describes what happens when the ventilation system shuts down?
a.
The supply and exhaust fans stop and the supply and exhaust dampers close. The argon and pneumatic transfer system hood fans also stop. The air is now confined to the reactor building.
b.
The supply fan stops and the supply and exhaust dampers close and an exhaust bypass damper opens. The argon and pneumatic transfer system hood fans also stop. The air is bypassed around the main exhaust manifold and discharged through a HEPA filter through the stack.
c.
The supply and exhaust fans stop and the supply and exhaust dampers close. The argon and pneumatic transfer system hood fans start to maintain the differential pressure. The air is now confined to the reactor building.
d.
The supply and exhaust fans stop and the supply damper closes. The argon and pneumatic transfer system hood fans also stop. The air continues to be slowly exhausted through the stack.
Category C: Facility and Radiation Monitoring Systems QUESTION C.07
[1.0 point]
Which ONE of the following statements best describes the reason for the 1 kW Pulse Interlock?
a.
It prevents the reactor operator from inadvertently pulsing while in automatic mode of operation above 1 kW.
b.
Pulsing at or below 1 kW will prevent the percent power scram from occurring during the transient.
c.
It prevents the magnitude of the pulse from causing the pool water temperature limit to be exceeded.
d.
It prevents the reactor from pulsing at power levels that produce measurably significant increases in fuel temperature.
QUESTION C.08
[1.0 point]
Which ONE of the following statements best describes why, if there is primary to secondary mixing inside the heat exchanger during normal operation, primary coolant does not flow into the cooling tower?
a.
The primary system is at a higher elevation than the secondary system, so the direction of flow is dictated by gravity.
b.
Primary system flow rate is higher than secondary system flow rate.
c.
Primary system pressure is lower than secondary system pressure.
d.
Primary system pressure is higher than secondary system pressure.
QUESTION C.09
[1.0 point]
All of the following statements regarding the pneumatic transfer system operation are true EXCEPT:
a.
The pneumatic transfer system is always under a positive pressure to prevent leakage out of the tubing.
b.
Exhaust air from the pneumatic transfer system passes through an absolute filter before being discharged to the building exhaust system.
c.
Specimen capsules are drawn into and out of the core by vacuum.
d.
The terminus of the pneumatic transfer system is always located in the G-ring.
Category C: Facility and Radiation Monitoring Systems QUESTION C.10
[1.0 point]
Which ONE of the following statements regarding nuclear reactor instrumentation use during pulse operations is true?
a.
The period channel and safety channels are grounded, and the percent power channel will receive a power scram signal but will not cause the reactor to scram until after the pulse.
b.
The percent power and safety channels are grounded, and the period channel will receive a period scram signal but will not cause the reactor to scram until after the pulse.
c.
The period channel and percent power channels are grounded, and the safety channel will receive a power scram signal but will not cause the reactor to scram until after the pulse.
d.
All automatic reactor scrams are disabled in pulse mode, except the high voltage and preset timer scrams.
QUESTION C.11
[1.0 point]
Which ONE of the following options correctly describes how primary coolant temperature is measured?
a.
A thermocouple detects changes in pool temperature by measuring the voltage difference between two wires of dissimilar metals.
b.
A resistance temperature detector detects changes in pool temperature by measuring changes in resistance to the flow of electricity resulting from changes in temperature of the resistive metal element.
c.
A semiconductor-based temperature sensor detects changes in pool temperature by utilizing two identical diodes with temperature-sensitive voltage vs current characteristics that are used to monitor changes in temperature.
d.
A thermistor detects changes in pool temperature by using a thermally sensitive resistor that exhibits a continuous, small, incremental change in resistance correlated to variations in temperature.
Category C: Facility and Radiation Monitoring Systems QUESTION C.12
[1.0 point]
Which ONE of the following statements correctly describes the reason for maintaining a differential pressure between the reactor bay and the external atmosphere?
a.
Operating with the reactor bay maintained at a positive pressure ensures all leakage is into the reactor bay rather than out, controlling the release of radioactive effluents to the environment.
b.
Operating with the reactor bay maintained at a negative pressure ensures leakage is out of the reactor bay, controlling the release of radioactive effluents through the stack to ensure appropriate radiological controls for occupational workers.
c.
Operating with the reactor bay maintained at a positive pressure ensures leakage is out of the reactor bay, controlling the release of radioactive effluents through the stack to ensure appropriate radiological controls for occupational workers.
d.
Operating with the reactor bay maintained at a negative pressure ensures all leakage is into the reactor bay rather than out, controlling the release of radioactive effluents to the environment.
QUESTION C.13
[1.0 point]
Which ONE of the following statements best describes what happens to the transient rod when a scram signal is received?
a.
The 3-way air solenoid valve is de-energized, causing air pressure to be increased on top of the piston resulting in the transient rod dropping due to the force of the increased pressure.
b.
The 3-way air solenoid valve is energized, causing air pressure to be increased on top of the piston resulting in the transient rod dropping due to the force of the increased pressure.
c.
The 3-way air solenoid valve is de-energized, causing the air pressure under the piston to vent and resulting in the transient rod dropping.
d.
The 3-way air solenoid valve is energized, causing the air pressure under the piston to vent and resulting in the transient rod dropping.
Category C: Facility and Radiation Monitoring Systems QUESTION C.14
[1.0 point]
In accordance with Technical Specifications, all of the following statements regarding Radiation Monitoring Channels requirements are correct EXCEPT:
a.
Required radiation monitoring at the reactor top include the reactor top Area Radiation Monitor and the Continuous Air Particulate Radiation Monitor.
b.
If a single required radiation monitor becomes inoperable during reactor operations, operation may continue for one hour with no substitutions made.
c.
The reactor top Continuous Air Gaseous Radiation Monitor is not required to be operable.
d.
If the reactor top Area Radiation Monitor becomes inoperable, it may be substituted with the reactor top Continuous Air Gaseous Radiation Monitor for periods not to exceed one month.
QUESTION C.15
[1.0 point]
Which one of the following statements best describes the method of core cooling at OSTR?
a.
Radiative heat transfer combined with forced-flow cooling b.
Natural convection combined with forced-flow cooling c.
Evaporative cooling with forced-flow convection d.
Forced-flow convection QUESTION C.16
[1.0 point]
When operating in automatic mode, which ONE of the following channels provides the signal input used by the servo system?
a.
Safety channel b.
Log-N channel c.
NVT channel d.
Wide range linear channel
Category C: Facility and Radiation Monitoring Systems QUESTION C.17
[1.0 point]
Which ONE of the following materials constitutes the bulk of the primary coolant piping?
a.
Aluminum b.
Stainless steel c.
Carbon steel d.
PVC QUESTION C.18
[1.0 point]
All of the following experimental locations discharge air through the argon manifold vent to the reactor bay ventilation main exhaust EXCEPT:
a.
Rotating specimen rack b.
Pneumatic transfer system c.
Beam ports d.
Vertical irradiation tubes QUESTION C.19
[1.0 point]
Which ONE of the following statements describes when and how the emergency power systems are maintained during a loss of power to the reactor facility?
a.
System A loads are interrupted by a loss of power. The generator starts immediately to supply power to the UPS and the System A loads. System B loads are unaffected because they receive power from the UPS.
b.
System A and B loads are interrupted by a loss of power. The generator automatically starts within 10 seconds to supply power to both loads.
c.
System B loads are interrupted by a loss of power. The generator starts immediately to supply power to the System B loads and the UPS. System A loads are unaffected because they receive power from the UPS.
d.
System B loads are interrupted by a loss of power. The generator automatically starts within 10 seconds to supply power to the System B loads and the UPS. System A loads are unaffected because they receive power from the UPS.
Category C: Facility and Radiation Monitoring Systems QUESTION C.20
[1.0 point]
Which ONE of the following best describes the reason for the high sensitivity of a Geiger-Mueller detector?
a.
Any incident radiation event causing primary ionization results in ionization of the entire detector.
b.
The detector has a large tube which increases the target area for all incident events.
c.
The lower voltage applied to the detector better amplifies incident events.
d.
The U-235 lining causes high ionizations at low concentrations.
(***** END OF CATEGORY C *****)
((********** END OF EXAMINATION **********))
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics A.01 Answer:
c.
Reference:
DOE Fundamentals Handbook, Volume 1, Module 1, p. 46 A.02 Answer:
a.
Reference:
DOE Fundamentals Handbook, Volume 2, Module 3, p. 16 A.03 Answer:
- a. 1 (Fissionable); b. 3 (Fissile); c. 2 (Fertile); d. 3 (Fissile)
Reference:
DOE Fundamentals Handbook, Volume 1, Module 1, p. 50-52 A.04 Answer:
b.
Reference:
Reactor power keeps increasing because period is positive.
A.05 Answer:
b.
Reference:
DOE Fundamentals Handbook Volume 1, Module 1, p. 61 A.06 Answer:
a.
Reference:
DOE Fundamentals Handbook, Volume 2, Module 3, p. 21,
T*T
= (-0.00075 k/k/ oF) * (-15 oF)
= 0.01125 k/k A.07 Answer:
c.
Reference:
DOE Fundamentals Handbook, Volume 2, Module 4, p. 7 A.08 Answer:
a.
Reference:
DOE Fundamentals Handbook, Volume 1, Module 2, p. 3 OSTR Training Manual, Volume 3, p. 42 A.09 Answer:
b.
Reference:
DOE Fundamentals Handbook, Volume 2, Module 3, p. 26 A.10 Answer:
c.
Reference:
CR1 / CR2 = (1 - Keff2) / (1 - Keff1) 250 / 470 = (1 - Keff2) / (1 - 0.395)
Therefore Keff2 = 0.678
= (Keff2 - Keff1) / (Keff2
- Keff1)
= (0.678- 0.395) / (0.678
- 0.395)
= 1.057
Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics A.11 Answer:
d.
Reference:
Burn, Introduction to Nuclear Reactor Operations, Figure 8-1, p. 8-6.
A.12 Answer:
c.
Reference:
Burn, R., Introduction to Nuclear Reactor Operation, Section 5.3, p. 5-12 A.13 Answer:
a.
Reference:
P = P0et/T 3 = 1
- et/32 ln(3) = ln(et/32) 1.099 = t/32 t = 35.2 sec A.14 Answer:
- a. 3; b. 1; c. 2
Reference:
DOE Fundamentals Handbook, Volume 2, Module 4, p. 11-12 A.15 Answer:
- a. 1 (Stays the same); b. 3 (Increases); c. 2 (Decreases); d. 1 (Stays the same)
Reference:
DOE Fundamentals Handbook, Volume 2, Module 3, p. 2-9.
A.16 Answer:
b.
Reference:
DOE Fundamentals Handbook, Volume 2, Module 3, p. 28 A.17 Answer:
b.
Reference:
Burn, Introduction to Nuclear Reactor Operations, Section 2.7, 2-63 A.18 Answer:
c.
Reference:
Standard NRC question A.19 Answer:
d.
Reference:
DOE Fundamentals Handbook, Volume 1, Module 2 p. 29
(***** END OF CATEGORY A *****)
Category B: Normal/Emergency Operating Procedures and Radiological Controls B.01 Answer:
c.
Reference:
OSTR Emergency Plan, p. 3-6 B.02 Answer:
b.
Reference:
OSTROP 1, Annunciator Response Procedures B.03 Answer:
d.
Reference:
6 Cen = R/hr at 1 ft (6 x 3 Ci) x (0.75
- 0.15) 2.03 R/hr at 1 ft B.04 Answer:
a.
Reference:
OSTROP 4, Reactor Operations Procedure B.05 Answer:
- a. 2 (Semi-annually); b. 3 (Annually); c. 3 (Annually); d. 1 (Monthly)
Reference:
OSTR Technical Specifications 4.2, 4.3, 4.5, 4.7 B.06 Answer:
b.
Reference:
10 CFR 20.1301 B.07 Answer:
Reference:
10 CFR 20.1003 B.08 Answer:
c.
Reference:
OSTROP 11, Fuel Element Handling Procedures B.09 Answer:
a.
Reference:
OSTROP 1, Annunciator Response Procedures
Category B: Normal/Emergency Operating Procedures and Radiological Controls B.10 Answer:
c.
Reference:
DR = DR0*e-X Find :
100 = 250*e -*15 0.4 = e-*15 ln(0.4) = ln(e-*15)
-0.916 = -*15
= 0.0611 If insertion of an HVL (thickness of lead), the original intensity will be reduced by half.
Find X:
1 = 2* e-0.0611*X 0.5 = e-0.0611*X ln(0.5) = ln(e-0.0611*X)
-0.693 = -0.0611*X X= 11.3 mm B.11 Answer:
d.
Reference:
OSTR Emergency Plan B.12 Answer:
- a. 3 (Class C); b. 2 (Class B); c. 2 (Class B); d. 1 (Class A)
Reference:
OSTROP 18, Procedures for the Approval and Use of Reactor Experiments B.13 Answer:
d.
Reference:
10 CFR Part 55.21, 55.53, 55.59 B.14 Answer:
c.
Reference:
OSTR Emergency Plan, p. 5-2 B.15 Answer:
- a. 2 (Test); b. 1 (Check); c. 1 (Check); d. 3 (Calibration)
Reference:
OSTR Technical Specifications 1.2, 1.3, 1.4 B.16 Answer:
b.
Reference:
OSTR Technical Specifications 4.0 B.17 Answer:
d.
Reference:
OSTR Technical Specifications 6.2.3 B.18 Answer:
a.
Reference:
OSTROP 8, Reactor Power Calibration Procedures.
Category B: Normal/Emergency Operating Procedures and Radiological Controls B.19 Answer:
- c.
Reference:
OSTR Technical Specifications 3.1.3, 3.1.4, 3.2.1, 3.3 B.20 Answer:
d.
Reference:
OSTROP 12, Control Rod Maintenance, Removal, and Replacement Procedures
(***** END OF CATEGORY B *****)
Category C: Facility and Radiation Monitoring Systems C.01 Answer:
d.
Reference:
c.
Reference:
b.
Reference:
OSTR SAR 11.1.1.1 C.04 Answer:
c.
Reference:
b.
References:
OSTR SAR 7.7.2 OSTR Training Manual Volume 4, 5.2.1 C.06 Answer:
a.
Reference:
d.
Reference:
OSTR Technical Specification 3.2.3 C.08 Answer:
c.
Reference:
a.
Reference:
a.
References:
OSTR SAR 7.2.3.1 OSTR Training Manual Volume 2, Section 5 C.11 Answer:
a.
Reference:
d.
Reference:
OSTR Technical Specifications 5.1
Category C: Facility and Radiation Monitoring Systems C.13 Answer:
c.
Reference:
d.
Reference:
OSTR Technical Specifications 3.7.1 C.15 Answer:
b.
Reference:
d.
Reference:
a.
Reference:
b.
References:
OSTR SAR 9.1.3 OSTR Training Manual 8.1.3 C.19 Answer:
d.
Reference:
a.
Reference:
NRC Standard question
(***** END OF CATEGORY C *****)
((********** END OF EXAMINATION **********))