Text

Examination Report Letter No. 50-602/OL-25-01, University of Texas - Austin
	ML25092A126
Person / Time
Site:	University of Texas at Austin
Issue date:	07/09/2025
From:	Tony Brown; NRC/NRR/DANU/UNPO
To:	Charlton W; University of Texas at Austin
References
	50-602/25-001
	Download: ML25092A126 (38)
	v • d • e

Dr. William Charlton, Director Nuclear Engineering Teaching Laboratory The University of Texas at Austin 10100 Burnet Road, Building 159 Austin, TX 78758

SUBJECT:

EXAMINATION REPORT NO. 50-602/OL-25-01, UNIVERSITY OF TEXAS - AUSTIN

Dear Dr. Charlton:

During the week of May 12, 2025, the U.S. Nuclear Regulatory Commission (NRC) administered an operator licensing examination at your University of Texas at Austin. 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 Michele DeSouza at 301-415-0747 or via email at Michele.DeSouza@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. 50-602

Enclosures:

1. Examination Report No. 50-602/OL-25-01

2. Written examination cc: w/enclosures to GovDelivery Subscribers July 9, 2025 Signed by Brown, Tony on 07/09/25

ML25092A126 NRR-079 OFFICE NRR/DANU/UNPO/CE NRR/DANU/UNPO/OLA NRR/DANU/UNPO/BC NAME MDeSouza NJones TBrown DATE 7/9/2025 7/9/2025 7/9/2025 U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.:

50-602/OL-25-01 FACILITY DOCKET NO.:

50-602 FACILITY LICENSE NO.:

R-129 FACILITY:

University of Texas - Austin EXAMINATION DATES:

Week of May 12, 2025 SUBMITTED BY:

SUMMARY

During the week of May 12, 2025, the NRC administered operator licensing examinations to two Reactor Operator (RO) and two Senior Reactor Operator - Upgrade (SRO-U) candidates. Both RO candidates failed the written examination. Both SRO-U candidates passed their operating tests.

REPORT DETAILS 1.

Examiner:

Michele C. DeSouza, Chief Examiner, NRC 2.

Results:

RO PASS/FAIL SRO PASS/FAIL TOTAL PASS/FAIL Written 0/2 N/A 0/2 Operating Tests 2/0 2/0 4/0 Overall 0/2 2/0 2/2 3.

Exit Meeting:

Paul Whaley, Associate Director, University of Texas - Austin James Terry, Reactor Manager, University of Texas - Austin Tony Brown, UNPO Branch Chief, NRC Michele C. DeSouza, Chief Examiner, NRC Margaret Goodwin, Examiner in Training, NRC 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.

Michele C. DeSouza 7/8/2025 Name, Chief Examiner Date University of Texas TRIGA Reactor Operator Licensing Examination Week of May 12, 2025 U. S. NUCLEAR REGULATORY COMMISSION NON-POWER REACTOR LICENSE EXAMINATION FACILITY:

University of Texas REACTOR TYPE:

TRIGA DATE ADMINISTERED:

May 14, 2025 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% or greater in each category and a 70% or greater 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 as well as a grade of 70 percent or greater 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)

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 ___

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)

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 ___

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 ___

(***** 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)

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

SCR

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

1 1

d DR d

DR

t e

DR DR

0

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 Doppler Broadening?

a. The probability of a neutron escaping the resonance region.

b. The change in shape of the resonance with temperature.

c.

An increase in the probability that a neutron will be absorbed by U-238.

d. The increase in average neutron energy in the core leading to a decrease in scattering cross sections.

QUESTION A.02

[1.0 point]

Which ONE of the following statements regarding fission fragments is TRUE?

a. Initial fission fragments are always highly energetic and highly ionized.

b. There will always only be two fission fragment atoms generated through each fission event.

c.

The smaller the fission fragment, the greater the kinetic energy imparted on it through fission.

d. The energy of the fission fragments is the predominant energy used to achieve and maintain criticality.

QUESTION A.03

[1.0 point]

Which ONE of the following statements BEST describes a prompt supercritical reactor?

a. M = 0; Keff = 1; =

b.

M = ; Keff > 1; <

c.

M = 0; Keff < 1; <

d.

M = ; Keff > 1; >

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.04

[1.0 point]

Which ONE of the following statements BEST describes Radiative Capture?

a.

It is a process where a neutron is absorbed by a nucleus and gamma rays are emitted as a result.

b.

It is a process where a neutron strikes a nucleus which is originally in a ground state and the energy imparted by the neutron leaves the nucleus in an excited state.

c.

It is a process where a neutron is absorbed by the nucleus and the nucleus releases a proton and a beta particle in order to return to its original energy.

d.

It is a process where a neutron collides with a nucleus imparting significant energy, resulting in the nucleus splitting and releasing more neutrons as a result.

QUESTION A.05

[1.0 point]

Which ONE of the following elements has the LARGEST Mean Free Path?

a.

Boron ( = 105.2 cm-1) b.

Tungsten ( = 1.21 cm-1) c.

Plutonium ( = 31.1 cm-1) d.

Titanium ( = 0.323 cm-1)

QUESTION A.06

[1.0 point]

Which ONE of the following statements regarding subcritical multiplication is TRUE?

a.

The neutron source strength has no determination on the ultimate neutron population for its associated multiplication factor.

b.

Once the startup source has provided the initial neutron population for the first generation it is no longer needed to produce neutrons.

c.

As the multiplication factor gets closer to one, the time required for neutron population to stabilize increases.

d.

As the reactor approaches criticality, the startup source must be removed to prevent an inadvertent prompt jump.

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.07

[1.0 point]

If Kinf = 1.34, determine Keff for a reactor with a probability of fast non-leakage of 0.88 and a probability of thermal non-leakage of 0.92.

a.

1.08 b.

1.14 c.

1.20 d.

1.34 QUESTION A.08

[1.0 point]

Which ONE of the following statements BEST describes the purpose of a burnable poison?

a.

The purpose of a burnable poison is to ensure there is sufficient negative reactivity to provide an adequate shutdown margin throughout the life of the reactor.

b.

The purpose of a burnable poison is to account for the initial excess reactivity of a fresh core and generally burns up at the same rate as the fuel to maintain a constant excess reactivity.

c.

Burnable poisons are only generated through the operation of the reactor and thus serve no real purpose but requires excess reactivity to account for their formation.

d.

The purpose of a burnable poison is to ensure sufficient negative reactivity for future potential decommissioning.

QUESTION A.09

[1.0 point]

Which ONE of the following statements BEST describes Doubling Time?

a.

The amount of time it takes for reactor power to return to normal after a reactor pulse.

b.

The amount of time it takes for reactor power to increase by a factor of e.

c.

The amount of time it takes for reactor power to increase by a factor of 2.

d.

The number of decades that reactor power increases in a minute.

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.10

[1.0 point]

Which ONE of the following is NOT a function of poison Control Rods?

a.

Remove negative reactivity and add positive reactivity to achieve criticality through their movement.

b.

Moderate the fast neutrons generated from fission to maintain criticality.

c.

Shape the neutron flux around the core in the axial and radial directions.

d.

Provide adequate negative reactivity to maintain subcriticality when fully inserted.

QUESTION A.11

[1.0 point]

Which ONE of the following BEST describes Departure from Nucleate Boiling?

a.

The point at which a vapor film forms over the entirety of the fuel region resulting in a void.

b.

The point at which bubbles formed from boiling coalesce into a vapor covering some of the fuel.

c.

The point at which bubbles no longer collapse after leaving the surface of the fuel.

d.

The point at which the water surrounding the fuel begins to rapidly boil.

QUESTION A.12

[1.0 point]

What is the reactor period if = 0.007 and = 0.005?

a.

4.02 seconds b.

8.04 seconds c.

20.5 seconds d.

100.7 seconds

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.13

[1.00 point]

Which ONE of the following statements BEST describes the Liquid-Drop Model of a nucleus?

a.

The travel path of an atom in a reactor when traced, matches the flow of a single drop of water.

b.

The size on an atoms nucleus compared to the size of the whole atom is similar to the size of a drop of water compared to an ocean.

c.

The energy required to displace all the subatomic particles is similar to the energy required to disperse all the water molecules in a drop of water.

d.

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.

QUESTION A.14

[1.0 point]

Which ONE of the following is a characteristic of an effective core reflector?

a.

A low thermal conductivity.

b.

A small crystal expansion structure.

c.

A low resistance to radiation damage.

d.

A high scattering to absorption cross section ratio.

QUESTION A.15

[1.0 point]

Which ONE of the following statements BEST describes control rod shadowing?

a.

An effect in which the repositioning of one control rod changes the reactivity worth of adjacent rods.

b.

An effect in which the movement of the control rods changes the flux shape of the reactor core resulting in an appreciable real change in reactor power.

c.

An effect in which the placement of one control rod changes the flux profile of the core leading to a decrease in the fuel temperature and subsequent increase in reactor power.

d.

An effect in which the movement of one control rod changes the location of the fuel element with the highest power density.

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.16

[1.0 point]

In which ONE of the following in-core locations is the neutron diffusion theory of transport VALID?

a.

Next to the fuel.

b.

Next to the control rods.

c.

Near the boundary of the reactor.

d. In the water gaps between each fuel element.

QUESTION A.17

[1.0 point]

Which ONE of the following factors in the Six Factor Formula is NOT impacted by increasing the number of fuel elements in the core?

a.

The Reproduction Factor ()

b.

The Fast Fission Factor ()

c.

The Probability of Thermal Non-Leakage (PTNL) d.

The Probability of Fast Non-Leakage (PFNL)

QUESTION A.18

[1.0 point]

Which ONE of the following coefficients of reactivity is credited with immediately adding negative reactivity in response to a large prompt insertion of reactivity?

a.

Void Coefficient b.

Fuel Temperature Coefficient c.

Moderator Temperature Coefficient d.

Pressure Coefficient

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.19

[1.0 point]

Which ONE of the following statements BEST describes the damage fast neutrons do to core structures?

a.

Fast neutrons undergo absorption reactions which lead to the activation and eventual decay of the core structure.

b.

Fast neutrons displace metal atoms in core structures leading to brittleness, swelling, and a loss of strength.

c.

Fast neutrons undergo elastic scattering with the metal in the core structure, ionizing the material and leading to eventual degradation.

d.

Fast neutrons have one of the highest radiation weighting factors and cause long term damage through the high amounts of imparted energy.

QUESTION A.20

[1.0 point]

If reactor power is at 50 W and $1.25 worth of reactivity is added resulting in a 7 second period, what will reactor power be after 1 minute?

a.

116.2 kW b.

173.4 kW c.

263.9 kW d.

512.7 kW

(***** END OF CATEGORY A *****)

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.01

[1.0 point]

In accordance with OPER-1 Startup - Shutdown Checks, which ONE of the following systems does NOT need to be operable for reactor operations greater than 100 kW?

a.

Room 1.104 Evacuation Alarm b.

Pool Area Radiation Monitor c.

Reactor Pool Cooling d.

Reactor On mode of the HVAC QUESTION B.02

[1.0 point]

In accordance with OPER-2 Reactor Startup, Operating, and Shutdown, which ONE of the following statements BEST describes the reactivity addition during a Pulse?

a.

The transient rod drive is raised to some height based on the desired reactivity addition using the differential reactivity worth curve of the transient rod.

b.

The transient rod is fired from fully inserted to fully withdrawn once criticality has been established at 50 W without the use of the transient rod such that the same reactivity is added every time a Pulse is performed.

c.

Initial criticality is achieved using the transient rod such that the reactivity addition is based on the integral rod worth minus the reactivity lost from achieving the initial criticality at 50 W.

d.

Initial criticality is achieved using a transient rod height that is equal to the associated desired reactivity addition then the transient rod is inserted and forced out pneumatically to the previously calculated rod height to add the desired amount of reactivity.

QUESTION B.03

[1.0 point]

In accordance with the University of Texas Emergency Response Plan, which ONE of the following events would be considered a non-reactor specific event?

a.

Notification of a bomb in the reactor room.

b.

A tornado that causes damage to all facility ventilation systems.

c.

Fire in the reactor room that lasts less than 15 minutes.

d.

A sustained radiological dose rate of 20 mrem/hr at the site boundary.

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.04

[1.0 point]

In accordance with FUEL-1 Movement of Fuel, which ONE of the following instruments is NOT required when moving fuel?

a.

Neutron sensitive survey instrument b.

Air particulate monitor c.

Pool Area radiation monitor d.

Gamma sensitive survey instrument QUESTION B.05

[1.0 point]

In accordance with OPER-5 Operation of Air Confinement System, which ONE of the following statements best describes the flow of air in REACTOR OFF and REACTOR ON modes?

a.

In the REACTOR OFF mode, confinement isolation has been initiated so there is no airflow while in REACTOR ON mode, air flows normally through the facility maintaining a negative pressure differential.

b.

In the REACTOR OFF mode, air in the reactor bay is re-circulated through the HVAC system while in the REACTOR ON mode, reactor bay air is exhausted and fresh air is constantly brought in.

c.

In the REACTOR OFF mode, the HVAC system is secured and no air is circulated through the reactor bay while in REACTOR ON mode, the HVAC systems runs to maintain a consistent temperature and humidity.

d.

In REACTOR OFF mode, air flows in such a way that there is no difference in pressure between the reactor bay and other facility areas while in REACTOR ON mode, air flows in such a way to maintain a negative pressure differential.

QUESTION B.06

[1.00 point]

In accordance with MAIN-1 Interlock and SCRAM Features, which ONE of the following actions or conditions would place the Reactor in manual mode from auto mode?

a.

Inserting Shim 1 and Shim 2 to the fully inserted position.

b.

Attempting to withdraw any control rod while the neutron source is removed from the core.

c.

Depression of the Rod Magnet Switch button.

d.

Attempting to apply air to the transient rod while the drive is partially withdrawn.

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.07

[1.0 point]

In accordance with the University of Texas Technical Specifications, which ONE of the following experiments would be allowed in the core for irradiation?

a.

A singly encapsulated experiment containing 15g of Francium powder and 15g of Sodium powder.

b.

An experiment that contains 20 mg of TNT in a container rated to withstand the pressure from a detonation of 25 mg of TNT.

c.

A fueled experiment that upon irradiation would contain 250 mCi of I-131 and 600 mCi of I-133.

d.

An experiment containing Plutonium that if breeched would result in an uptake dose of 50 rem to the lungs.

QUESTION B.08

[1.0 point]

Which ONE of the following scenarios would result in an occupational worker violating their 10 CFR 20 annual dose limits?

a.

Handling a sample releasing a beta radiation dose of 2 rem/hr for 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

b.

Accidentally ingesting contaminated water, that results in a dose to the liver of 55 rem.

c.

Accidentally inhaling some radioactive powder that results in an uptake of 15 rem to the lungs.

d.

Handling a fueled experiment that emits a beta radiation dose of 50 rem/hr on contact for 3 minutes.

QUESTION B.09

[1.0 point]

In accordance with MAIN-1 Interlock and SCRAM Features, which ONE of the following statements with respect to the Operator Log In sequence is TRUE?

a.

All Reactor Operators are given a unique username and password that can only be used to log that operator in.

b.

Logging out as Reactor Operator without another operator logged in will result in an automatic reactor SCRAM.

c.

The Reactor Operator cannot log out of the system while the reactor is in the manual mode of operation.

d.

The reactor Prestart Checks sequence must be completed with a Reactor Operator logged into the system.

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.10

[1.0 point]

In accordance with Plan-E Emergency Response, which ONE of the following actions is NOT utilized to prevent the spread of radioactive contamination?

a.

Immediate measurement of activity on hands and feet.

b.

Identification of potential problem areas.

c.

Control of access to contamination hazard areas.

d.

Separation of people who may be potentially contaminated from those confirmed clean.

QUESTION B.11

[1.0 point]

In accordance with OPER-2 Reactor Startup, Operating, and Shutdown, how much reactivity should be added in order to increase reactor power from 800 W to 400 kW in the Square Wave mode? Assuming = 0.00700.

a.

0.00345 b.

0.00428 c.

0.00592 d.

0.00699 QUESTION B.12

[1.0 point]

In accordance with OPER-4 Operation of the Reactor Water Systems, which ONE of the following BEST describes how pool level is determined?

a.

It is the difference between the bottom of the reactor tank and the surface of the water.

b.

It is the difference between the midpoint of the core and the surface of the water.

c.

It is the difference between the bottom of the reactor tank and the height of the primary coolant inlet pipe.

d.

It is the difference between the midpoint of the core and the height of the primary coolant inlet pipe.

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.13

[1.0 point]

In accordance with HP-4 Radiation Protection Training, which ONE of the following BEST describes an individual at the Nuclear Engineering Training Laboratory who has NOT received Radiation Protection Training?

a.

Escort Required for Employee b.

Visitor c.

Trainee d.

Emergency Medical Responder QUESTION B.14

[1.0 point]

If a sample was removed from the rotary specimen rack emitting a dose rate of 360 mrem/hr at 10cm, 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 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

a.

1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months b.

2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months c.

4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months d.

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months QUESTION B.15

[1.0 point]

In accordance with the University of Texas Emergency Response Plan, what is the responsibility of the Reactor Operator in an emergency?

a.

The safe shutdown and securing of the reactor.

b.

Monitoring the event to provide the Emergency Director with up to date information.

c.

Supporting the Radiation Safety Officer with personnel decontamination and area surveys.

d.

Maintaining a written record of what initiated the declaration of the emergency and all subsequent response actions for later review and lessons learned.

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.16

[1.0 point]

In accordance with OPER-6 Reactor Bay Systems, which ONE of the following systems does NOT require log entries when maintenance is performed?

a.

Radiation Monitoring System b.

Pool Water System c.

Communications System d.

Room Confinement System QUESTION B. 17

[1.0 point]

If an experiment was removed from the core emitting a dose rate of 100 rem/hr on contact from beta radiation, how long would someone have to hold it in order to violate their 10 CFR 20 limits?

a.

3 minutes b.

15 minutes c.

30 minutes d.

60 minutes QUESTION B.18

[1.0 point]

In accordance with HP-1 Radiation Monitoring - Personnel, which ONE of the following statements regarding the wearing of personnel dosimetry is NOT true?

a.

All personnel going into a Restricted Area MUST wear a dosimeter.

b.

All personnel dosimetry must be sensitive to alpha, beta, neutron, and gamma radiation.

c.

Personnel dosimetry must be worn on the portion of the body that is expected to receive the highest dose.

d.

Personnel assigned a permanent record dosimeter may be required to wear a pocket dosimeter in addition to their permanent dosimetry as directed by Health Physics.

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.19

[1.0 point]

In accordance with EXP-PTS Pneumatic Transfer System, who is responsible for training people on how to use the system?

a.

Reactor Operators b.

There is no extra training required c.

The Reactor Supervisor or a designee d.

Anyone experienced with the system who has the NETL Radiation Safety Training QUESTION B.20

[1.0 point]

In accordance with SURV-6 Control Rod Calibration, which ONE of the following steps is NOT required when utilizing the Rod Drop Method?

a.

The rod being measured is to be fully withdrawn.

b.

The primary and secondary coolant pumps are secured.

c.

The control rod farthest from the one being calibrated is withdrawn to 900 units.

d.

The neutron source is removed from the core once criticality has been achieved.

(***** END OF CATEGORY B *****)

Category C: Facility and Radiation Monitoring Systems QUESTION C.01

[1.0 point]

Which ONE of the following statements best describes the Confinement Area at the University of Texas TRIGA Reactor?

a.

An area where the entire ventilation system is separate from the rest of the facility and includes associated isolation dampers.

b.

The area where the air for the rest of the facility flows before exiting through the exhaust system.

c.

The area of the facility where ventilation can be isolated from the rest of the building using dampers that bypass airflow.

d.

An area in the facility that has an entirely separate HVAC system which can only be run in Reactor On mode.

QUESTION C.02

[1.0 point]

In accordance with OPER-4 Operation of Reactor Water Systems, which ONE of the following is NOT a function of the pool water?

a.

Maintain adequate flux profiles in the core b.

Moderate neutrons c.

Cool the fuel d.

Provide radiation shielding QUESTION C.03

[1.0 point]

In accordance with the University of Texas Technical Specifications, which ONE of the following statements best describes the primary cause of fuel cladding failure?

a.

As the temperature of the fuel increases, the tensile and ductile strength of the cladding diminishes leading to embrittlement and eventual cracking.

b.

If the Safety Limit is surpassed, it is likely that the temperature of the fuel and cladding will surpass the melting point of the cladding leading to a rupture.

c.

The hydrogen in the fuel-moderator dissociates leading to a buildup of pressure which eventually surpasses the stress strength of the cladding.

d.

If the fuel surpasses the Safety Limit it will melt within the cladding leading to the production of corium within the cladding space, which then results in a buildup of pressure within the element leading to rupture.

Category C: Facility and Radiation Monitoring Systems QUESTION C.04

[1.0 point]

In accordance with the University of Texas Technical Specifications, which ONE of the following assumptions was made when determining the Limiting Condition of Operation of 1.1 MW as the maximum power level?

a.

The control rod with the greatest reactivity worth is stuck in the fully withdrawn position.

b.

Core cooling done via natural convection is sufficient.

c.

Peak fuel temperatures occur at a power level greater than 1.1 MW.

d.

The excess reactivity required to compensate for Xenon buildup still allows for a large enough shutdown margin.

QUESTION C.05

[1.0 point]

Which ONE of the following conditions would NOT prevent withdrawal of the Shim 1 Control Rod?

a.

Mode switch in one of the pulse positions.

b.

Mode switch in the AUTO position.

c.

Neutron source removed from the core.

d.

Scrams not reset.

QUESTION C.06

[1.0 point]

Which ONE of the following conditions would result in an automatic reactor SCRAM?

a.

A database timeout condition on the CSC.

b.

A reactor period of less than 3 seconds.

c.

High neutron flux from the NM-1000.

d.

Sudden increase in the high voltage supplied to the NM-1000 and then subsequent return to normal voltage.

Category C: Facility and Radiation Monitoring Systems QUESTION C.07

[1.0 point]

Which ONE of the following is NOT an engineered safety feature used at the University of Texas TRIGA Reactor?

a.

The design of the scram safety circuit.

b.

The fuel material type and fuel cladding.

c.

The design of the actuators for rod drives and control rods.

d.

The emergency core cooling system and associated make up water.

QUESTION C.08

[1.0 point]

Which ONE of the following scenarios would result in the automatic actuation of the ventilation isolation?

a.

A continuous air monitor (gaseous) alarm at 2*10-5 µCi/cm3.

b.

A continuous air monitor (particulate) alarm at 2*10-9 µCi/cm3.

c.

An area radiation monitor (gamma) alarm at 100 mr/hr.

d.

Failure of the Argon purge system while the reactor is operating.

QUESTION C.09

[1.0 point]

Which ONE of the following was NOT taken into consideration when designing reactor pool fuel storage system?

a.

Cooling b.

Shape c.

Shielding d.

Geometry QUESTION C.10

[1.0 point]

Which ONE of the following radionuclides was of greatest concern when designing the reactor confinement system?

a.

Xenon-133 b.

Cesium-137 c.

Argon-41 d.

Iodine-131

Category C: Facility and Radiation Monitoring Systems QUESTION C.11

[1.0 point]

Which ONE of the following experimental facilities can be used for the synchronous irradiation of multiple samples and production of radionuclides?

a.

Rotary Specimen Rack b.

Central Thimble c.

Radial Beam Ports d.

Pneumatic Specimen Tube QUESTION C.12

[1.0 point]

Which ONE of the following statements best describes the purpose for limiting the reactivity worth on an unsecured experiment?

a.

It is to prevent violating the limit on total core excess reactivity.

b.

It is to ensure that the maximum power of the reactor cannot exceed 1.9 MW thus protecting the fuel.

c.

It is to ensure that the shutdown margin is still great enough to shut the reactor down even with all experiments in their most reactive position.

d.

It is to avoid exceeding the core temperature safety limit by preventing the possibility of a prompt criticality due to sudden removal.

QUESTION C.13

[1.0 point]

Which ONE of the following features is utilized to prevent the complete loss of reactor tank water?

a.

A makeup water system to passively add water to tank as needed, determined by a water level monitor.

b.

An emergency core cooling system that immediately adds water to the tank in the event that the low level alarm is actuated.

c.

Anti-siphon breaks in the reactor tank and coolant piping to prevent suction of water from the tank in emergency situations.

d.

A circuit setup to automatically turn the primary pump off to prevent suction of water from the core upon actuation of the low level alarm.

Category C: Facility and Radiation Monitoring Systems QUESTION C.14

[1.0 point]

Which ONE of the following characteristics is true for ALL Control Rods used at the University of Texas TRIGA Reactor?

a.

They are all Stainless Steel clad.

b.

The all have uniform lengths and diameters.

c.

They utilize solid Boron Carbide as the neutron poison.

d.

They are all followed by fuel elements made of U-ZrH.

QUESTION C.15

[1.0 point]

Which ONE of the following conditions indicates a reactor pool tank leak?

a.

Having to add an abnormally large amount of makeup water in a week.

b.

An abnormally high water conductivity averaged over a month.

c.

A sudden increase in the pool water temperature.

d.

An increase in the pressure of the primary cooling system.

QUESTION C.16

[1.0 point]

During and after a reactor pulse, when does the outer fuel cladding temperature reach its maximum value?

a.

Peak cladding temperature occurs instantaneously with the associated pulse.

b.

Peak cladding temperature occurs on the order of milliseconds after the associated reactor pulse.

c.

Peak cladding temperature occurs on the order of a few seconds after the associated reactor pulse.

d.

Peak cladding temperature occurs on the order of a few minutes after the associated reactor pulse.

Category C: Facility and Radiation Monitoring Systems QUESTION C.17

[1.0 point]

Which ONE of the following actions would NOT impact the critical positions of the control rods?

a.

Previous reactor runs in excess of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months during the previous 5 days.

b.

An increase in the negative pressure differential between the Reactor Bay and outside.

c.

A decrease in the pool water temperature by 5O C.

d.

Movement of fuel into and out of the core.

QUESTION C.18

[1.0 point]

In accordance with EXP-PTS Pneumatic Transfer System, which ONE of the following statements best describes the basis for the power limit when using the Cadmium Lined Terminus?

a.

It is to ensure that the samples do not surpass the activation limit associated with the use of that terminus.

b.

It is to ensure that the temperature is low enough to prevent damage to the vial such that it will not get stuck in the core terminus.

c.

It is to ensure that the Safety Limit of the fuel is not surpassed in the event of a prompt criticality due to the experiment getting stuck in the core.

d.

It is to prevent the embrittlement of the sample vials which could in turn result in them breaking during removal, releasing radioactive material in the terminus.

QUESTION C.19

[1.0 point]

Which ONE of the following conditions would support valid results from a reactor power calibration?

a.

Leaving the pool lights on.

b.

The depth of the pool at the time of the calibration is 6.2 meters.

c.

The average temperature of the pool water at the time of calibration is approximately 20o C.

d.

The temperature of the concrete bio-shield at the time of calibration is 20o C greater than the ambient temperature.

Category C: Facility and Radiation Monitoring Systems QUESTION C.20

[1.0 point]

In accordance with the Technical Specifications, which ONE of the following statements best describes the purpose for maintaining a pool water pH of 7?

a.

It prevents the potential chemical interaction of the water with failed experiments.

b.

It prevents the potential corrosion of samples placed in the reactor core.

c.

It prevents the rapid decline of the resin in the water purification system.

d.

It prevents the aluminum components in the tank from becoming corroded.

(***** END OF CATEGORY C *****)

(********** END OF EXAMINATION **********)

a

Reference:

( ) = 0 (1 )

() () = (0 ) (0 )

() (0 ) = () (0 )

=

() (0 )

( 0 )

=

(400000 0.007) (800 0.007)

(400000 (800 0.007))

= 0.006986

Category B: Normal/Emergency Operating Procedures and Radiological Controls B.12 Answer:

a

Reference:

University of Texas OPER-4 Operation of Reactor Water Systems p. 4 B.13 Answer:

b

Reference:

University of Texas HP-4 Radiation Protection Training p. 4 B.14 Answer:

d

Reference:

12 1 = 22 2

360*100 = 2 900 2 = 40

= 0 0 40

5

=

ln (2)

= 2 5 = 40 ln(2) 2

ln 5

40 = ln(2) 2

ln(2) = ln 5

40 2

=

2 ln ( 5 40 )

ln (2)

= 6.0 B.15 Answer:

a

Reference:

University of Texas Emergency Response Plan 2.1.2 B.16 Answer:

c

Reference:

University of Texas OPER-6 Reactor Bay Systems p. 4 B.17 Answer:

c

Reference:

10 CFR 20 limits on extremity dose = 50 rem per year

=

50 100

= 0.5

= 30 B.18 Answer:

b

Reference:

University of Texas HP-1 Radiation Monitoring - Personnel p. 4 B.19 Answer:

c

Reference:

University of Texas EXP-PTS Pneumatic Transfer System p. 4

Category B: Normal/Emergency Operating Procedures and Radiological Controls B.20 Answer:

a

Reference:

University of Texas SURV-6 Control Rod Calibration p. 4

(***** END OF CATEGORY B *****)

ML25092A126

Text

SUBJECT:

Dear Dr. Charlton:

Enclosures:

SUMMARY

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Reference:

Navigation menu

Search