ML23107A187

Examination Report No. 50-223/OL-23-01, University of Massachusetts - Lowell

ML23107A187
Person / Time
Site:	University of Lowell
Issue date:	04/21/2023
From:	Travis Tate NRC/NRR/DANU/UNPO
To:	Prosanta Chowdhury Univ of Massachusetts - Lowell
References
50-223/OL-23-01 50-223/OL-23
Download: ML23107A187 (36)

Text

April 21, 2023 Dr. Partha Chowdhury, Director Nuclear Radiation Laboratory University of MassachusettsLowell One University Avenue Lowell, MA 01854

SUBJECT:

EXAMINATION REPORT NO. 50-223/OL-23-01, UNIVERSITY OF MASSACHUSETTSLOWELL

Dear Dr. Partha Chowdhury:

During the week of March 6, 2023, the U.S. Nuclear Regulatory Commission (NRC) administered operator licensing examinations at the University of MassachusettsLowell Research 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 you and 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. If you have any questions regarding the examination, please contact Amy Beasten at (301) 415-8341 or email at Amy.Beasten@nrc.gov.

Sincerely, Signed by Tate, Travis on 04/21/23 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. 50-223

Enclosures:

1. Examination Report No. 50-223/OL-23-01

2. Written Examination cc: GovDelivery Subscribers

P. Chowdhury 2

SUBJECT:

EXAMINATION REPORT NO. 50-223/OL-23-01, UNIVERSITY OF MASSACHUSETTSLOWELL DATED: APRIL 19, 2023 DISTRIBUTION:

PUBLIC JBowen, NRR JGreives, NRR TTate, NRR JBorromeo, NRR EHelvenston, NRR LTran, NRR AWaugh, NRR ABeasten, NRR TLe, NRR DTifft, RGN-I RMcKinley, RGN-I ADAMS ACCESSION No.: ML23107A187 NRR-079 Office NRR/DANU/UNPO/CE NRR/DANU/UNPO/OLA NRR/DANU/UNPO/BC Name ABeasten NJones TTate Date 4/19/2023 4/19/2023 4/19/2023 OFFICIAL RECORD COPY

U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.: 50-223/OL-23-01 FACILITY DOCKET NO.: 50-223 FACILITY LICENSE NO.: R-125 FACILITY: University of MassachusettsLowell Research Reactor EXAMINATION DATES: March 6-9, 2023 SUBMITTED BY: _Amy E. Beasten 03/30/2023 Amy E. Beasten, Chief Examiner Date

SUMMARY

During the week of March 6, the NRC administered operator licensing examinations to three Reactor Operator (RO) candidates. 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 3/0 0/0 3/0 Operating Tests 3/0 0/0 3/0 Overall 3/0 0/0 3/0

3. Exit Meeting:

Amy E. Beasten, Reactor Engineer, NRC Travis L. Tate, Branch Chief, NRC Tuan Le, Reactor Engineer, NRC Leo Bobek, Reactor Supervisor, University of MassachusettsLowell Thomas Rigaw, Training Manager, University of MassachusettsLowell 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.

Enclosure 1

University of Massachusetts - Lowell Operator Licensing Examination Week of March 05, 2023 Enclosure 2

U.S. NUCLEAR REGULATORY COMMISSION NON-POWER REACTOR LICENSE EXAMINATION FACILITY: University of Massachusetts-Lowell REACTOR TYPE: POOL DATE ADMINISTERED: 03/05/2023 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

Category A - Reactor Theory, Thermodynamics, & Facility Operating Characteristics ANSWER SHEET 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 ___

A04 a b c d ___

A05 a b c d ___

A06 a ________ b ________ c ________ d ________ (0.50 each)

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 ___

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

Category B - Normal/Emergency Operating Procedures and Radiological Controls ANSWER SHEET 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 ___

B06 a ________ b ________ c ________ d ________ (0.25 each)

B07 a b c d ___

B08 a b c d ___

B09 a ________ b ________ c ________ d ________ (0.25 each)

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 ANSWER SHEET 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

2 Q m c P T m H UAT Pmax eff 0.1sec 1 2

t P P0 e S S SCR

• 110 4 sec 1 K eff 1 eff

• SURP26.06 P0 CR1 1 K eff1 CR2 1 K eff 2 CR1 1 CR2 2 P P0 10 SUR (t )

1 K eff1 1 CR K eff 2 K eff1 M M 2 1 K eff 2 1 K eff CR1 K eff1 K eff 2

= + [ ]

SDM 1 K eff T1 0.693 K eff 2 K eff 1 2

DR1 d1 DR2 d 2 2 6 Ci E n K eff DR R2 DR DR0 e t 2 2 1 2 Peak2 Peak1 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

Category A - Reactor Theory, Thermodynamics, & Facility Operating Characteristics QUESTION A.01 [1.0 point]

The process in which a neutron strikes a nucleus leaving the nucleus in an excited state is referred to as:

a. Elastic scattering.

b. Inelastic scattering.

c. Photoelectric effect.

d. Neutron annihilation.

QUESTION A.02 [1.0 point]

What is the amount of positive reactivity (%k/k) that is added to a subcritical reactor when Keff is increased from 0.600 to 0.750?

a. 33.333

b. 88.888

c. 91.500

d. 95.750 QUESTION A.03 [1.0 point]

Which ONE of the following best explains the importance of source neutrons?

a. Source neutrons are essential to achieve and maintain criticality of the reactor.

b. Source neutrons ensure that there is a sufficient neutron population to provide visible indication of neutron level during start-up and 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 there is a sufficient neutron population to overcome the effects of fission product poisoning following a shutdown.

Category A - Reactor Theory, Thermodynamics, & Facility Operating Characteristics QUESTION A.04 [1.0 point]

The moderator temperature coefficient for a reactor is -0.00082 k/k/oF. What is the total reactivity change caused by a temperature decrease of 75oF?

a. 0.0018

b. 0.0028

c. 0.0205

d. 0.0615 QUESTION A.05 [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. Fuel burnup

c. Increase in fuel temperature

d. Xenon and Samarium fission products QUESTION A.06 [2.0 point, each 0.50]

Match the following statements 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 Column B

a. Thermal Utilization Factor Increases

b. Thermal Non-Leakage Probability Decreases

c. Resonance Escape Probability Stays the same

d. Fast Fission Factor

Category A - Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.07 [1.0 point]

Which ONE of the following statements is MOST correct about prompt neutrons?

a. Prompt neutrons are produced from spontaneous fission of the U-235 in the fuel.

b. Prompt neutrons are produced immediately and directly from the fission event.

c. Prompt neutrons are emitted immediately following the first beta decay of a fission fragment.

d. Prompt neutrons are responsible for the ability to control the rate at which power can rise in a reactor.

QUESTION A.08 [1.0 point]

The following data 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. 1 to 2

b. 3 to 4

c. 5 to 7

d. 8 to 10 QUESTION A.09 [1.0 point]

During fission of U-235, the majority of energy is released in the form of ________.

a. Fission neutrons

b. Neutrinos

c. Capture gamma rays

d. Fission fragments

Category A - Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.10 [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 larger increase in neutron flux resulting in a longer time to stabilize.

b. Each reactivity insertion results in a smaller increase in neutron flux resulting in a shorter time to stabilize.

c. Each reactivity insertion results in a larger increase in neutron flux resulting in a shorter time to stabilize.

d. Each reactivity insertion results in a smaller increase in neutron flux resulting in a longer time to stabilize.

QUESTION A.11 [1.0 point]

Given a reactor period of 48 seconds, approximately how long will it take for power to quadruple?

a. 33 seconds

b. 46 seconds

c. 66 seconds

d. 100 seconds QUESTION A.12 [1.0 point]

Following a reactor scram, the period meter will indicate _______ because ________.

a. Slightly positive; the neutron source is providing detectable neutron count rate to keep the reactor slightly supercritical.

b. 0 seconds; the reactor is subcritical and reactor power is decreasing.

c. -80 seconds; the fuel temperature coefficient adds positive reactivity as a result of the decrease in fuel temperature following a scram.

d. -80 seconds; of the decay constant for the longest-lived neutron precursor.

Category A - Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.13 [1.0 point]

Which ONE of the following isotopes is an example of a fissile material?

a. U-238

b. Pu-240

c. Th-232

d. U-233 QUESTION A.14 [1.0 point]

Define :

a. The total fraction of delayed neutrons weighted by the percent of all neutrons contributed by the fuel.

b. The fraction of neutrons at thermal energies which were born as delayed neutrons.

c. The total fraction of all neutrons born as delayed neutrons.

d. The fraction of neutrons at fast energies which were born as delayed neutrons.

QUESTION A.15 [1.0 point]

Which ONE of the following statements regarding fission product poisoning is NOT true?

a. Following a reactor shutdown, the concentration of Sm-149 reaches a peak because some fission is still occurring in the core.

b. During normal reactor operation, Sm-149 is removed from the core by neutron absorption.

c. Following a reactor shutdown, the concentration of Xe-135 reaches a peak based on the decay of I-135 in the core.

d. During normal reactor operation, Xe-135 is removed from the core by radioactive decay and neutron absorption.

Category A - Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.16 [1.0 point]

Which ONE of the following describes Integral Rod Worth?

a. The summation of all the reactivity worth of a rod up to the point of withdrawal

b. The plot of the slope of the change in reactivity over the change in rod position (/x)

c. The reactivity change per unit movement of a rod.

d. The total reactivity worth of the rod at a particular degree of withdrawal QUESTION A.17 [1.0 point]

Which ONE of the following decay chains correctly describes the production and removal of X-135 from the reactor?

a. I135 - + Te135 - + Xe135 -+ Cs135 - + Ba135

b. Te135 - + I135 - + Xe135 -+ Ba135 - + Cs135

c. Te135 - + I135 - + Xe135 -+ Cs135 - + Ba135

d. Te135 - + Cs135 - + Xe135 -+ I135 - + Ba135 QUESTION A.18 [1.0 point]

Given a source strength of 250 neutrons per second (N/sec) and a multiplication factor of 0.5, which ONE of the following is the expected stable neutron count rate?

a. 150 N/sec.

b. 250 N/sec.

c. 400 N/sec.

d. 500 N/sec.

Category A - Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.19 [1.0 point]

The Thermal Utilization Factor is defined as:

a. The ratio of the number of thermal neutrons produced by fission in a generation to the number of total neutrons produced by fission in the previous generation.

b. The ratio of the number of thermal neutrons absorbed in fuel to the number of thermal neutrons absorbed in the reactor material.

c. The ratio of the number of fast neutrons absorbed in fuel to the number of fast neutrons absorbed in the reactor material.

d. The ratio of the number of fast neutrons produced by thermal fission to the number of thermal neutrons absorbed in the fuel.

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

Category B - Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.01 [1.0 point]

According to the UMLRR Emergency Plan, which ONE of the following individuals will have the authority to terminate an emergency?

a. The Reactor Safety Subcommittee Chairman

b. Reactor Supervisor

c. Reactor Operator on duty

d. Chief of Police, University of Massachusetts Lowell Police QUESTION B.02 [1.0 point]

In accordance with 10 CFR 20, individual members of the public are limited to an annual TEDE of:

a. 50 mrem.

b. 100 mrem.

c. 500 mrem.

d. 5000 mrem.

QUESTION B.03 [1.0 point]

According to the UMLRR Emergency Plan, the Emergency Planning Zone is defined as:

a. The University of Massachusetts campus boundary.

b. The Pinanski Building and the area bounded by the fence around the reactor containment building.

c. The area within a 150-ft radius beyond the walls of the reactor containment building.

d. The reactor containment building.

QUESTION B.04 [1.0 point]

An irradiated sample has a dose rate of 1.0 rem/hr as indicated at a distance of 1 foot from the sample. How far from the irradiated sample will the dose rate read 100 mrem/hr?

a. 3.16 ft.

b. 5.17 ft.

c. 7.00 ft.

d. 10.00 ft.

Category B - Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.05 [1.0 point]

What is the MINIMUM number of hours per calendar quarter you must perform the functions of an RO to maintain an active RO license in accordance with 10 CFR Part 55.53(e)?

a. 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />

b. 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />

c. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />

d. 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> QUESTION B.06 [1.0 point, each 0.50]

Match the scenarios in Column A with the appropriate emergency classifications listed in Column B. Options in Column B may be used once, more than once, or not at all.

Column A Column B

a. Personnel injury with radiological Non-Reactor Safety Event complications Unusual Event

b. Fire on the reactor console that requires Lowell Fire Department response Alert

c. Indications of a loss of pool water at a Site Area Emergency rate that exceeds the ability of the makeup system to recover

d. Hurricane Warning in effect QUESTION B.07 [1.0 point]

High radiation alarms are received on the reactor experimental level and the stack gaseous monitor. All of the following are actions to be taken by the Reactor Operator EXCEPT:

a. Verify ventilation system is operating to dilute and dissipate any airborne radiological effluents.

b. Scram the reactor and secure the console.

c. Initiate building evacuation.

d. Return the Co-60 source to the bottom of the pool.

Category B - Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.08 [1.0 point]

The radiation level in the control room is 75 mrem/hour, and the operator is in the control room for 10 minutes. How much dose will the operator receive?

a. 1.0 mrem

b. 7.5 mrem

c. 12.5 mrem

d. 20 mrem QUESTION B.09 [1.0 point, each 0.25]

Match surveillance requirements in Column A with the surveillance interval listed in Column B.

Options in Column B may be used once, more than once, or not at all.

Column A Column B

a. Core excess reactivity verification Quarterly

b. Pool water radioactivity analysis Monthly

c. Emergency exhaust system operability Semi-Annually check Annually

d. Ventilation isolation valve operability verification QUESTION B.10 [1.0 point]

When is direct supervision by a licensed Senior Reactor Operator NOT required?

a. Initial reactor startup and approach to power

b. Insertion of a routine movable experiment with a known reactivity worth of 0.02% k/k

c. Recovery from power reduction of 200kW or greater

d. Relocation of control rods within the reactor core

Category B - Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.11 [1.0 point]

Which ONE of the following is the definition of Committed Dose Equivalent?

a. The sum of external deep dose equivalent and the organ dose equivalent.

b. The dose equivalent that the whole body receives from sources outside the body.

c. The sum of the effective dose equivalent (for external exposures) and the committed effective dose equivalent (for internal exposures).

d. 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 QUESTION B.12 [1.0 point]

According to the UMLRR Technical Specifications, which ONE of the following conditions is NOT permissible while the reactor is operating?

a. The shutdown margin is 2.3% k/k.

b. The core excess reactivity is 4.2% k/k.

c. Truck door not sealed due to equipment delivery.

d. Control room Area Radiation monitor inoperable.

QUESTION B.13 [1.0 point]

In accordance with RO-5, Reactor Operations, all of the following are actions to take in response to an unexpected power decrease EXCEPT:

a. Shut down the reactor by driving all control blades and the regulating rod into the core.

b. Place the reactor in manual mode if it is in automatic.

c. Withdraw the control blades to restore power to the desired level.

d. Notify the SRO.

QUESTION B.14 [1.0 point]

You are currently a licensed operator at UMLRR. Which ONE of the following would be a violation of 10 CFR Part 55.53 Conditions of licenses?

a. The new requalification program cycle started 18 months ago.

b. Your last medical examination was 16 months ago.

c. Your last requalification operating test was 13 months ago.

d. Last quarter you were the licensed operator for 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

Category B - Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.15 [1.0 point]

Per UMLRR Technical Specifications, when the area radiation monitor located over the reactor pool is inoperable, reactor operations:

a. May continue so long as the Constant Air Monitor is still operable.

b. May continue if the inoperable scram channel is bypassed within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of discovery

c. Must be suspended immediately.

d. May continue if the monitor is repaired or replaced with a monitor of similar function within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of discovery.

QUESTION B.16 [1.0 point]

Upon receipt of indications of a rapid loss of pool water, all of the following actions should be taken in accordance with EO-6 EXCEPT:

a. Scram the reactor and verify reactor is shutdown.

b. Open the make-up valve.

c. Ensure the primary and secondary pumps are stopped, and the cleanup pump is running to allow makeup water to enter.

d. Alert the Emergency Team by pressing the ALARM button on the ARM cabinet.

QUESTION B.17 [1.0 point]

In order to ensure the health and safety of the public, 10 CFR 50.54(x) allows the operator to deviate from Technical Specifications in an emergency. What is the minimum level of authorization needed to deviate from Technical Specifications in accordance with 10 CFR 50.54(y)?

a. Director of Reactor Operations

b. Radiation Laboratory Director

c. Licensed Senior Reactor Operator.

d. Licensed Reactor Operator.

Category B - Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.18 [1.0 point]

In accordance with RO-4, which ONE of the following statements is true concerning experiment insertion or removal?

a. Samples with an expected absolute reactivity worth of 0.25%k/k may be inserted via the pneumatic tube system.

b. Flux trap samples with a reactivity worth of > 0.25%k/k shall be considered secured experiments.

c. Secured experiments may be added or removed from the core if the reactor power does not change by more than 3%.

d. Samples that affect reactivity by 0.5%k/k or less are not considered to have significant reactivity worth.

QUESTION B.19 [1.0 point]

An experiment reading 30 rem/hr was removed from the reactor. Five hours later, it reads 1 rem/h. What is the half-life of the experiment?

a. 1.23

b. 1.10

c. 1.02

d. 0.50 QUESTION B.20 [1.0 point]

Which ONE of the following defines the term Radiation Area?

a. Any area to which access is limited for any reason.

b. Any area to which access is limited for the purpose of protecting individuals against undue risks from exposure to radiation and radioactive materials.

c. Area where radiation exposure rates would result in a dose equivalent in excess of 5 mrem (0.05 mSv) in one hour at 30 centimeters from the radiation source.

d. Area where radiation exposure rates would result in a dose equivalent in excess of 0.1 rem (1 mSv) in one hour at 30 centimeters from the radiation source.

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

Category C - Facility and Radiation Monitoring Systems QUESTION C.01 [1.0 point]

Which ONE of the following channels provides indication of reactor period?

a. Log-N channel

b. Start-up channel

c. Linear channel 1

d. Safety Channel QUESTION C.02 [1.0 point, each 0.50]

Which ONE of the following detector combinations might indicate a fuel leak?

a. Continuous Air Monitor 1 and Demineralizer

b. Reactor Bridge and Demineralizer

c. Fission Products and Demineralizer

d. Continuous Air Monitor 2 and Demineralizer QUESTION C.03 [1.0 points]

Which ONE of the following best describes the difference between a Potential Local Radiation Emergency Alarm (P-LREA) and a Potential General Radiation Emergency Alarm (P-GREA)?

a. The P-LREA requires manual operator action to isolate containment and a reactor scram, where the P-GREA automatically initiates both those functions.

b. The P-GREA requires manual operator response to isolate containment and a reactor scram, where the P-LREA automatically initiates both those functions.

c. The P-LREA requires manual operator action to isolate containment, whereas the P-GREA automatically initiates a containment isolation signal.

d. The P-GREA requires manual operator action to isolate containment, whereas the P-LREA automatically initiates a containment isolation signal.

Category C - Facility and Radiation Monitoring Systems QUESTION C.04 [1.0 point]

During a reactor startup, which ONE of the following reasons might explain why control blades will not withdraw from the core?

a. Primary coolant pump not on.

b. Source range level indication is 7 cps.

c. Limit switch contacts in the scram chain are reset and energized.

d. Linear channel 2 reading below 5% of selected range.

QUESTION C.05 [1.0 point]

The figure below depicts which ONE of the following nuclear instrumentation detectors?

a. Logarithmic Power/Period Channel

b. Linear Channel

c. Start-up Channel

d. Safety Channel QUESTION C.06 [1.0 point]

Which ONE of the following best describes the UMLRR fuel?

a. High enrichment (>20% U-235) U3Si2, clad with stainless steel, or high enrichment (>20% U-235) UAlx clad with aluminum.

b. Low enrichment (<20% U-235) U3Si2, clad with aluminum, or low enrichment (<20% U-235)

UAlx, clad with aluminum.

c. High enrichment (>20% U-235) U3Si2, clad with aluminum, or high enrichment (>20% U-235)

UAlx clad with aluminum.

d. Low enrichment (<20% U-235) U3Si2, clad with stainless steel, or low enrichment (<20% U-235) UAlx, clad with aluminum.

Category C - Facility and Radiation Monitoring Systems QUESTION C.07 [1.0 point]

Complete the following statement:

________ is the preferred method of forced convection cooling because ________.

a. Cross-stall mode; it reduces vibrations to the core suspension structure.

b. Downcomer mode; it reduces vibrations to the core suspension structure.

c. Cross-stall mode; it is more effective at cooling the core during full power operations because cooled water is discharged directly over the core.

d. Downcomer mode; it is more effective at cooling the core during full power operations because cooled water is discharged directly over the core.

QUESTION C.08 [1.0 point]

What is the neutron source used for startup at UMLRR?

a. Plutonium-Beryllium

b. Neptunium-Antimony

c. Americium-Beryllium

d. Californium-252 QUESTION C.09 [1.0 point]

What is the purpose of the emergency exhaust system?

a. The emergency exhaust system is intended to relieve small overpressures as accompanied by airborne radioactivity in containment building.

b. The emergency exhaust system is intended to maintain the containment differential pressure.

c. The emergency exhaust system is intended to isolate the containment building from the environment during radiological emergencies.

d. The emergency exhaust system is intended to serve as a backup to the normal facility ventilation system in the event the normal ventilation becomes inoperable.

Category C - Facility and Radiation Monitoring Systems QUESTION C.10 [1.0 point]

Which ONE of the following best describes what happens to the control blades when a scram signal is initiated?

a. The scram magnet is energized, the control blade anvil is released, and the control blade and lift-rod assemblies fall into the core under the force of gravity.

b. The scram magnet is de-energized, the control blade anvil is released, and the control blade and lift-rod assemblies fall into the core under the force of gravity.

c. The drive motor is de-energized, the control blade anvil is released, and the drive mechanism runs the control blades into the core.

d. The drive motor is energized, the control blade anvil is released, and the drive mechanism runs the control blades into the core.

QUESTION C.11 [1.0 point]

The gaseous effluent most commonly produced from reactor operation is _______ which is

a. N-16; produced from irradiation of water

b. Ar-41; produced from irradiation of air

c. Rn-222; a naturally occurring isotope

d. I-135; produced as a byproduct of fission QUESTION C.12 [1.0 point]

Which ONE of the following is the Technical Specification definition of CHANNEL CALIBRATION?

a. A Channel calibration is the introduction of a signal into the channel for verification that it is operable.

b. A Channel calibration is the measured value of a parameter as it appears on the output for a channel.

c. A Channel calibration is an adjustment of the channel such that its output corresponds with acceptable accuracy to known values of the parameter which the channel measures.

d. A Channel calibration is a qualitative verification of acceptable performance by observation of channel behavior, or by comparison of the channel with other independent channels or systems measuring the same parameter.

Category C - Facility and Radiation Monitoring Systems QUESTION C.13 [1.0 point]

In the event of a loss of normal electrical power, if the emergency generator fails to start, the uninterrupted power supply (UPS) will continue to supply power to the:

a. Emergency exhaust system

b. Area Radiation Monitors

c. Primary and Secondary cooling pumps

d. Reactor console and Nuclear Instrumentation cabinets QUESTION C.14 [1.0 point]

During steady state operations in automatic mode, the automatic control suddenly disengages without operation action. All of the following events or conditions could have caused this to happen EXCEPT:

a. The regulating rod has reached its fully withdrawn position due to rod drift.

b. The reactor bridge area radiation monitor alarms unexpectedly.

c. Reactor period indicates less than 30 seconds due to instrumentation malfunction.

d. There is a deviation of greater than 2% between the selected power setpoint and actual power as a result of experiment removal from the pneumatic transfer system.

QUESTION C.15 [1.0 point]

A recent set of thermal column experiments requires the reactor to be operated in T-mode. You are the Reactor Operator on Duty, and this is the first reactor operation since the bridge was moved to support these experiments. As power approaches 110kW, a reactor trip unexpectedly occurs. What could have been the cause of the scram?

a. Misalignment of the primary coolant connections on the bridge.

b. Primary coolant flow is less than 1400 GPM.

c. Pool inlet temperature is 110° F.

d. Reactor power is increasing on a 10 second period.

Category C - Facility and Radiation Monitoring Systems QUESTION C.16 [1.0 point]

Which ONE of the following best describes the anti-siphon system?

a. The anti-siphon system ensures the core does not become uncovered during a loss of coolant event by admitting a fixed volume of air into the high point of the primary coolant piping in the event of a primary coolant system rupture.

b. The anti-siphon system ensures the core does not become uncovered during a loss of coolant event by admitting a fixed volume of water into the high point of the primary coolant piping in the event of a primary coolant system rupture.

c. The anti-siphon system ensures the core does not become uncovered during a loss of coolant event by automatically closing a series of valves in the primary piping system when the pool level drops to 12 feet above the core.

d. The anti-siphon system ensures the core does not become uncovered during a loss of coolant event by alarming in the control room when the pool level drops to 12 feet above the core to alert the operator that manual action must be taken to close a series of valves in the primary piping system.

QUESTION C.17 [1.0 point]

Which ONE of the following isotopes would indicate a potential primary to secondary coolant leak in the heat exchanger?

a. O-19

b. Ar-41

c. Na-24

d. I-135 QUESTION C.18 [1.0 point]

Which ONE of the following statements describes how the reactor ventilation system closes on receipt of a valid signal?

a. Valves A, B, C, E, G, and H open to bypass air flow from the main intake fan up the stack for dilution. Valve F closes. The main exhaust fan and experimental facility blowers stop.

b. Valves A, B, C, E, F, G, and H close. The main exhaust fan and experimental facility blowers continue to operate to maintain airflow up the stack for dilution.

c. Valves A, B, C, E, G, and H close. Valve F opens to bypass air flow from the main intake fan up the stack for dilution. The main exhaust fan and experimental facility blowers stop.

d. Valves A, B, C, E, F, G, and H close. The main exhaust fan and experimental facility blowers stop.

Category C - Facility and Radiation Monitoring Systems QUESTION C.19 [1.0 point]

Which ONE of the following best describes what happens if the safety limit is exceeded?

a. Loss of the integrity of the fuel elements due to increasing voids between the fuel elements as a result of increasing moderator temperature.

b. Loss of integrity of the fuel elements due to decreased cooling flow around the elements.

c. Loss of integrity of the fuel elements due to increased thermal expansion.

d. Loss of the integrity of the fuel element cladding resulting in blistering of the fuel.

QUESTION C.20 [1.0 point]

Which ONE of the following options correctly describes how primary coolant temperature is measured?

a. 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.

b. 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.

c. A thermocouple detects changes in pool temperature by measuring the voltage difference between two wires of dissimilar metals.

d. 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.

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

((********** END OF EXAM **********))

Category A - Reactor Theory, Thermodynamics, & Facility Operating Characteristics A.01 Answer: b

Reference:

DOE Fundamentals Handbook, Volume 1, Module 1, p. 45.

A.02 Answer: a

Reference:

Burn, Introduction to Nuclear Reactor Operations, Section 3.3.4, p. 3-23.

= (Keff1-Keff2)/(Keff1*Keff2)

= (0.750-0.600) / (0.750*0.600)

= 0.3333

• 100

= 33.333% k/k A.03 Answer: b

Reference:

DOE Fundamentals Handbook, Volume 1, Module 2, p. 1 A.04 Answer: d

Reference:

DOE Fundamentals Handbook, Volume 2, Module 3, p. 21,

T*T

= (-0.00082 k/k /oF) * (-75oF)

= 0.0615k/k A.05 Answer: b

Reference:

Standard NRC question A.06 Answer: a. Increases; b. Decreases; c. Decreases; d. Stays the same

Reference:

DOE Fundamentals Handbook, Volume 2, Module 3, p. 2-9.

A.07 Answer: b

Reference:

DOE Handbook, Fundamentals of Nuclear Engineering, Volume 1, Module 1, p.

29 A.08 Answer: c

Reference:

Burn, R., Introduction to Nuclear Reactor Operations, © 1982, Sec 5.5, p. 5-18 to 5-25 A.09 Answer: d

Reference:

Burn, Introduction to Nuclear Reactor Operations, Section 3.2.1, Table 3.2, p.

3-5.

A.10 Answer: a

Reference:

Burn, R., Introduction to Nuclear Reactor Operation, Section 5.3, p. 5-12

Category A - Reactor Theory, Thermodynamics, & Facility Operating Characteristics A.11 Answer: c

Reference:

P = P0et/T 4 = 1

• et/48 t = 48

• ln(4) t = 66.5 sec A.12 Answer: d

Reference:

DOE Handbook Nuclear Physics & Reactor Theory, Volume 1, Module 2, p. 7 A.13 Answer: d

Reference:

NRC Glossary, Fertile material, Fissionable material, Fissile material A.14 Answer: c

Reference:

DOE Fundamentals Handbook, Volume 1, Module 1, p. 30 A.15 Answer: a

Reference:

DOE Fundamentals Handbook, Volume 2, Module 3, p. 30-47 A.16 Answer: d

Reference:

Burn, Introduction to Nuclear Reactor Operations, Section 3.4, p. 3-32.

A.17 Answer: c

Reference:

Burn, Introduction to Nuclear Reactor Operations, Figure 8-1, p. 8-6.

A.18 Answer: d

Reference:

CR = S / (1-k)

S = CR / (1-k)

S = 250 / (1-0.5)

S = 500 N/sec.

A.19 Answer: b

Reference:

DOE Fundamentals Handbook Volume 2, Module 3, p. 4

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

Category B - Normal/Emergency Operating Procedures and Radiological Controls B.01 Answer: b

Reference:

UMLRR Emergency Plan, Section 3.1.1 B.02 Answer: b

Reference:

10 CFR 20.1301 B.03 Answer: d

Reference:

UMLRR Emergency Plan, Section 2.11 B.04 Answer: a

Reference:

DR1*(D1)² = DR2*(D2)² 1000 mrem (1)² = 100 mrem (d)² D = 3.16 ft.

B.05 Answer: a

Reference:

10 CFR 55.59 B.06 Answer: a. Non-Reactor Safety Related Event; b. Alert; c. Alert; d. Unusual Event

Reference:

UMLRR Emergency Plan, Appendix B B.07 Answer: a

Reference:

UMLRR EO-1 B.08 Answer: c

Reference:

Dose = DR*T 75 mRem/hr/60 minutes = 1.25 mRem/min 1.25mRem/min

• 10 min = 12.5 mRem B.09 Answer: a. Annually; b. Monthly; c. Quarterly; d. Semi-annually

Reference:

UMLRR TS, Sections 4.1, 4.3, 4.4 4.5 B.10 Answer: b

Reference:

UMLRR Technical Specifications 6.1.3 B.11 Answer: d

Reference:

10 CFR 20.1003 B.12 Answer: c

Reference:

UMLRR Technical Specifications 3.1.1, 3.4.2, 3.6.1

Category B - Normal/Emergency Operating Procedures and Radiological Controls B.13 Answer: c

Reference:

UMLRR RO-5 B.14 Answer: c

Reference:

10 CFR 55.59(a)(1)

B.15 Answer: d

Reference:

UMLRR Technical Specifications 3.6.1 B.16 Answer: c

Reference:

UMLRR EO-6 B.17 Answer: c

Reference:

10CFR50.54(y), UMLRR Emergency Plan Section 3.1.2 B.18 Answer: b

Reference:

UMLRR RO-4 B.19 Answer: c 0.693

Reference:

DR = DR0 , T1 =

2 DR = DR0 e-.693/T1/2 1.0 = 30 e-(.693)(5)/T1/2 0.033 = e-(.693)(5)/T1/2 ln(0.033) = ln(e-(.693)(5)/T1/2)

-3.401 = -3.465 / T1/2 T1/2 = -3.465 / -3.401 T1/2 = 1.02 hr B.20 Answer: c

Reference:

10 CFR 20.1003

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

Category C - Facility and Radiation Monitoring Systems C.01 Answer: a

Reference:

UMLRR SAR, Section 7.4.1.2 C.02 Answer: c

Reference:

UMLRR SAR Section 7.7.6 C.03 Answer: c

Reference:

UMLRR SAR Section 7.7.5 C.04 Answer: d

Reference:

UMLRR SAR 7.3.3 C.05 Answer: c

Reference:

UMLRR SAR Section 7.4.1.3 C.06 Answer: b

Reference:

UMLRR Technical Specification 5.3 C.07 Answer: a

Reference:

UMLRR SAR Section 5.2 C.08 Answer: c

Reference:

UMLRR SAR Section 4.2.4 C.09 Answer: a

Reference:

UMLRR SAR Section 6.2.4 C.10 Answer: b

Reference:

UMLRR SAR Section 4.2.2.1 C.11 Answer: b

Reference:

UMLRR SAR Section 11.1.1 C.12 Answer: c

Reference:

UMLRR Technical Specification 1.3 C.13 Answer: d

Reference:

UMLRR SAR Section 8.2

Category C - Facility and Radiation Monitoring Systems C.14 Answer: b

Reference:

UMLRR SAR Section 7.3.5 C.15 Answer: a

Reference:

UMLRR SAR Section 3.5.8 C.16 Answer: a

Reference:

UMLRR SAR Section 4.2.4 C.17 Answer: c

Reference:

UMLRR SAR Section 4.2.3.1 C.18 Answer: c

Reference:

UMLRR SAR Section 6.2.3 C.19 Answer: d

Reference:

UMLRR Technical Specification 2.1 C.20 Answer: d

Reference:

UMLRR SAR Section 7.4.2.2

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

((********** END OF EXAM **********))