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Examination Report No. 50-297-OL-16-02, North Carolina State University
	ML16130A580
Person / Time
Site:	North Carolina State University
Issue date:	05/11/2016
From:	Anthony Mendiola; Research and Test Reactors Oversight Branch
To:	Hawari A; North Carolina State University
	John T. Nguyen
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ML16014A398	List: ML16013A371; ML16130A580;
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	50-297/OL-16-002
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May 11, 2016 Dr. Ayman I. Hawari, Director Nuclear Reactor Program Department of Nuclear Engineering North Carolina State University Campus Box 7909 2500 Stinson Drive Raleigh, NC 27695-7909

SUBJECT:

EXAMINATION REPORT NO. 50-297/OL-16-02, NORTH CAROLINA STATE UNIVERSITY

Dear Dr. Hawari:

During the week of April 18, 2016, the U.S. Nuclear Regulatory Commission (NRC) administered operator licensing examinations at your North Carolina State University 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 at the conclusion of the examination with Greg Gibson, NCSU Senior Reactor Operator, as identified in the enclosed report.

In accordance with Section 2.390 of Title 10 of the Code of Federal Regulations, 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 NRCs Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

The NRC is forwarding the individual grades to you in a separate letter which will not be released publicly. If you have any questions concerning this examination, please contact Mr.

John T. Nguyen at (301) 415-4007 or via email at John.Nguyen@nrc.gov.

Sincerely,

/RA/

Anthony J. Mendiola, Chief Research and Test Reactors Oversight Branch Division of Policy and Rulemaking Office of Nuclear Reactor Regulation Docket No. 50-297

Enclosures:

1. Examination Report No. 50-297/OL-16-02

2. Written examination cc: w/o enclosures: See next page

North Carolina State University Docket No. 50-297 cc:

Office of Intergovernmental Relations 116 West Jones Street Raleigh, NC 27603 Dr. Kostadin Ivanov, Head Department of Nuclear Engineering North Carolina State University Campus Box 7909 Raleigh, NC 27695-7909 W. Lee Cox, Section Chief Department of Health and Human Services Division of Health Service Regulation Radiation Protection Section 1645 Mail Service Center Raleigh, NC 27699-1645 Dr. Louis Martin-Vega, Dean College of Engineering North Carolina State University 113 Page Hall Campus Box 7901 Raleigh, NC 27695-7901 Test, Research, and Training Reactor Newsletter University of Florida 202 Nuclear Sciences Center Gainesville, FL 32611

ML OFFICE NRR/DPR/PROB/CE NRR/DPR/PROB/OLA NRR/DPR/PROB/BC NAME JNguyen CRevelle AMendiola DATE 04/27/2016 05/09/2016 05/11/2016 ENCLOSURE 1 U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.: 50-297/OL-16-01 FACILITY DOCKET NO.: 50-297 FACILITY LICENSE NO.: R-120 FACILITY: North Carolina State University Pulstar Reactor EXAMINATION DATES: April 18 - April 20, 2016 SUBMITTED BY: __________/RA/ ________ _4/27/2016 John T. Nguyen, Chief Examiner Date

SUMMARY

During the week of April 18, 2016, the NRC administered operator licensing examination to two Reactor Operator (RO) license candidates. The entire license candidates passed all applicable portions of the examinations.

REPORT DETAILS

1. Examiners: John T. Nguyen, Chief Examiner, NRC

2. Results:

RO PASS/FAIL SRO PASS/FAIL TOTAL PASS/FAIL Written 2/0 0/0 2/0 Operating Tests 2/0 0/0 2/0 Overall 2/0 0/0 2/0

3. Exit Meeting:

John Nguyen, NRC, Chief Examiner Greg Gibson, NCSU, Senior Reactor Operator The examiner thanked the facility for their assistance during the exam administration.

ENCLOSURE 2 U. S. NUCLEAR REGULATORY COMMISSION NON-POWER REACTOR LICENSE EXAMINATION FACILITY: NORTH CAROLINA STATE UNIVERSITY REACTOR TYPE: PULSTAR DATE ADMINISTERED: April 19, 2016 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

A. RX THEORY, THERMO & FAC OP CHARS 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 ___

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 ___

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 *****)

B. NORMAL/EMERG PROCEDURES & RAD CON 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 ___ (0.25 each)

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 *****)

C. PLANT AND RAD 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 ___ (0.25 each)

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 ___ (0.25 each)

C09 a b c d ___

C10 a b c d ___

C11 a ___ b ___ c ___ d ___ (0.50 each)

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 ___

(***** 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 eff = 0.1sec 1 Q&= m&cP T = m&H = UAT Pmax =

(2 )

t P = P0 e S S SCR = * =1x104 sec 1 K eff eff + &

SUR = 26.06

( )

CR1 1 K eff1 CR

= CR1 ((

2 1 1 )K

= CR )

eff 2 2 ( 2 )

(1 ) M=

1

= 2 CR P = P0 10SUR(t )

P= P0 1 K eff CR1 1 K eff1 1 K eff

M= SDM = =

1 K eff 2 K eff

0.693 K eff 2 K eff1

+ T1 =

eff 2 K eff1 K eff 2 K eff 1

= DR = DR0 et 2 DR1 d1 = DR2 d 2 2

K eff 6 Ci E (n) ( 2 )2 = (1 )2 DR =

R2 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-lbf °F = 9/5 °C + 32 1 gal (H2O) 8 lbm °C = 5/9 (°F - 32) cP = 1.0 BTU/hr/lbm/°F cp = 1 cal/sec/gm/°C

North Carolina State University Operator Licensing Examination Week of April 18, 2016 ENCLOSURE 2

Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 1 QUESTION A.01 [1.0 point]

In a comparison between a delayed neutron and a prompt neutron born from the same fission event, the delayed neutron is more likely to:

a. leak out of the core.

b. be absorbed in the moderator.

c. cause fission of a U-238 nucleus.

d. cause fission of a U-235 nucleus.

QUESTION A.02 [1.0 point]

A reactor with Keff = 0.7 contributes 1000 neutrons in the first generation. Changing from the first generation to the THIRD generation, how many total neutrons are there after the third generation?

a. 1400

b. 1700

c. 2190

d. 2800

Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 2 QUESTION A.03 [1.0 point]

A reactor is slightly supercritical with the following values for each of the factors in the six-factor formula:

Fast fission factor 1.05 Fast non-leakage probability 0.80 Resonance escape probability 0.90 Thermal non-leakage probability 0.92 Thermal utilization factor 0.80 Reproduction factor 1.86 A control rod is inserted to bring the reactor back to critical. Assuming all other factors remain unchanged, the new value for the thermal utilization factor is:

a. 0.682

b. 0.712

c. 0.773

d. 0.873 QUESTION A.04 [1.0 point]

The reactor is SHUTDOWN by 5% k/k with the count rate of 1000 counts per second (cps).

The control rods are withdrawn until the count rate is quadrupled. What is the value of Keff ?

a. 0.952

b. 0.976

c. 0.988

d. 1.002

Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 3 QUESTION A.05 [1.0 point]

The product of number density and microscopic cross section of an element is defined as:

a. Macroscopic Cross Section.

b. Maximum Cross Section.

c. Thermal Cross Section.

d. Decay Constant.

QUESTION A.06 [1.0 point]

While a reactor is at 5 W, the reactor operator is withdrawing a control rod to insert a positive reactivity of 156 pcm. Which ONE of the following will be the stable reactor period as a result of this withdrawal? Given beta-effective = 0.0073 and eff= 0.1.

a. 17 seconds

b. 27 seconds

c. 37 seconds

d. 47 seconds QUESTION A.07 [1.0 point]

Which term is described by the following?

The fractional change of the effective multiplication factor from criticality.

a. 1/M

b. K-effective

c. Reactor period

d. Reactivity

Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 4 QUESTION A.08 [1.0 point]

Which ONE of the following most correctly describes the SIX- FACTOR FORMULA?

a. Keff = K

the total non-leakage probability

b. K = Keff

the total non-leakage probability

c. Keff = K

the total leakage probability

d. K = Keff

the utilization factor QUESTION A.09 [1.0 point]

A reactor is subcritical with a Keff of 0.927. If you add 7.875% k/k into the core, the reactor will be:

a. subcritical.

b. just critical.

c. supercritical.

d. prompt critical.

QUESTION A.10 [1.0 point]

The NCSU reactor is critical at 5 W. A reactor operator accidentally inserts a fuel element worth 1000 pcm into the core. With this insertion, a reactor will be:

a. subcritical

b. critical

c. supercritical

d. prompt critical

Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 5 QUESTION A.11 [1.0 point]

A mechanism by which a nucleus can gain stability by converting a neutron to a proton or vice versa is called:

a. gamma decay

b. beta decay

c. alpha decay

d. photoelectric effect QUESTION A.12 [1.0 point]

The MAIN reason for operating a reactor with thermal neutrons instead of fast neutrons is:

a. The fission cross section of the fuel is much higher for fast neutrons than thermal energy neutrons. Since fast neutrons are easier to cause fission, a reactor cannot control with fast neutrons.

b. The neutron lifetime of thermal neutrons is longer than fast neutrons, so the fuel has enough time to capture thermal neutrons.

c. The fission cross section of the fuel is much higher for thermal energy neutrons than fast neutrons, so thermal neutrons are easier to cause fission.

d. The atomic weight of thermal neutrons is larger than fast neutrons, so thermal neutrons are easily to slow down and be captured by the fuel.

QUESTION A.13 [1.0 point]

Why are burnable poisons added to a reactor core during initial core loading? The main reason is to:

a. Increase the availability of usable nuclear fuel with the existing control rod design.

b. Shape the fast neutron flux for maximum specimen irradiation capability.

c. Reduce the secondary isotopic radiation effects from irradiated control rods.

d. Shape the thermal neutron flux for maximum specimen irradiation capability.

Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 6 QUESTION A.14 [1.0 point, 0.33 each]

Match the term listed in Column A with its corresponding units listed in column B. Answer in Column B can be used once, more than once, or not at all.

Column A Column B

a. Microscopic Cross Section 1. 1/cm

b. Macroscopic Cross Section 2. 10 -24 cm 2

c. Neutron Flux 3. Neutrons / cm 2 /sec

. 4. Neutrons / cm 3 /sec

5. 10 -24 cm 3 QUESTION A.15 [1.0 point]

Following a positive reactivity addition to a shutdown reactor, the neutron power will increase even though k-effective is less than 1. The MAIN reason is due to:

a. Production of fast neutrons

b. Neutron moderation in the fuel

c. Subcritical multiplication process

d. Void temperature coefficient in the moderator QUESTION A.16 [1.0 point]

On the average, how many neutrons are produced for each fission of U-235?

a. 2.00 neutrons

b. 2.09 neutrons

c. 2.43 neutrons

d. 2.93 neutrons

Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 7 QUESTION A.17 [1.0 point]

Given the following Core Reactivity Data during startup:

Control Rod Total Rod Worth Rod Worth removed (pcm) critical at 5 W (pcm)

Rod # 1 2000 1500 Rod # 2 3000 2000 Rod # 3 4000 3500 Total 9000 7000 The Core Excess Reactivity is:

a. 2000 pcm

b. 3000 pcm

c. 4000 pcm

d. 7000 pcm QUESTION A.18 [1.0 point]

Reactor is at full power. The following graph shows the reactor time behavior following a reactor scram. Which ONE of the following best describes the transition of power between point A and B after the initial insertion? .

a. An immediate decrease in the prompt neutron fraction due to leakage, absorption, and a reduction in the fission rate.

b. Fission product gases such as xenon begin to buildup causing the expansion of fuel density.

c. Neutron level in the core is sustained by prompt neutrons.

d. Delayed neutron precursors would begin to effect.

Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 8

Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 9 QUESTION A.19 [1.0 point]

If the mean generation time for neutrons in a reactor is 0.1 sec and k = 1.001, what is the reactor period?

a. 1 seconds

b. 10 seconds

c. 100 seconds

d. 180 seconds QUESTION A.20 [1.0 point]

The reactor is on a CONSTANT positive period. Which ONE of the following power changes will take the longest time to complete?

a. 5%, from 95% to 100%

b. 10%, from 80% to 90%

c. 15%, from 15% to 30%

d. 20%, from 60% to 80%

- - - - End of Section A *****************

Section B - Normal/Emergency Procedures and Radiological Controls Page 10 QUESTION B.01 [1.0 point]

Radiation Work Permit (RWP) provides specific radiological precautions and practices while performing work activities outside of normal conditions for the purpose of limiting personnel radiation dose and spread of contamination. The below items are listed as conditions for obtaining a RWP, EXCEPT:

a. Entry into potential Radiation Area.

b. Entry into potential Contaminated Area.

c. Entry into potential Airborne Radioactivity Area.

d. Remove the control rod out of the reactor core for repairing.

QUESTION B.02 [1.0 point]

What is the maximum allowable dose that the Emergency Director can authorize for a volunteer in order to make a corrective action to protect valuable property?

a. 5 Rem

b. 10 Rem

c. 25 Rem

d. 50 Rem QUESTION B.03 [1.0 point, 0.25 each]

Match type of radiation listed in column A with their quality factor listed in column B. Items in column B can be used once, more than once or not at all.

Column A Column B

a. X-ray 1. 1

b. Gamma 2. 5

c. Alpha particles 3. 10

d. High-energy photons 4. 20

Section B - Normal/Emergency Procedures and Radiological Controls Page 11 QUESTION B.04 [1.0 point]

A radioactive source reads 5 Rem/hr on contact. Five hours later, the same source reads 1.25 Rem/hr. How long is the time for the source to decay from a reading of 5 Rem/hr to 625 mRem/hr?

a. 5.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months

b. 7.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months

c. 9.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months

d. 11.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months QUESTION B.05 [1.0 point]

A reactor has been operated at full power with an experiment in the core. Which ONE of the following is NOT a Tech Spec violation?

a. The Stack Gas Monitor pump has been turned OFF during the reactor operation.

b. The N-16 Channel has not been operable during the reactor operation.

c. The Stack Particulate Monitor has not been operable during reactor operation.

d. You review the irradiation request form and find that the total of the reactivity worths of all experiment is 2.0 % k/k.

QUESTION B.06 [1.0 point]

Per NCSU Technical Specifications, the MAXIMUM excess reactivity shall be:

a. 1000 pcm

b. 1590 pcm

c. 3970 pcm d 4970 pcm

Section B - Normal/Emergency Procedures and Radiological Controls Page 12 QUESTION B.07 [1.0 point]

Per NCSU Emergency Plan, the boundary that includes BEL, the area between Lampe and Broughton Drive and the area between Stinson Drive and the north face of BEL, is defined as:

a. Site Boundary.

b. Offsite Boundary.

c. Operations Boundary.

d. Containment Boundary.

QUESTION B.08 [1.0 point]

A five-curie source (Co-60), emits 100% of a 1.17 Mev and 1.33 Mev gamma, is to be stored in the reactor building. What is the exposure rate at 6 feet from the source?

a. 1.3 R/hr

b. 2.1 R/hr

c. 8.3 R/hr

d. 208 R/hr QUESTION B.09 [1.0 point]

Which ONE of the following is a MINIMUM staffing requirement when the reactor is NOT secured?

a. 1 Reactor Facility Director in the control room + 1 SRO on call + 1 HP on-call

b. 1 RO in the control room + 1 staff member + 1 RO on call + 1 HP on-call

c. 1 RO in the control room +1 HP in the control room + 1 SRO on call

d. 1 SRO in the control room + 1 RO on call + 1 HP on call

Section B - Normal/Emergency Procedures and Radiological Controls Page 13 QUESTION B.10 [1 point]

During a reactor operation, the reactor operator observes that the pool water temperature exceeds 120 °F. For this temperature, which ONE of the following is the best action?

a. The operator may increase power level to verify that at what temperature a reactor scram will be actuated.

b. The operator may continue an operation because the temperature is within TS limit.

c. The operator shall secure the reactor, and immediately report the result to the supervisor because the reactor safety system did not activate a scram.

d. The operator shall secure the reactor, and immediately report the result to the supervisor because the reactor safety system did not activate a Rod Withdraw Prohibit.

QUESTION B.11 [1.0 point]

Which ONE of the following is NOT a By-product Material?

a. Pu-239

b. Cobalt-57

c. Carbon-14

d. Tritium QUESTION B.12 [1.0 point]

Which ONE of the following correctly describes the limitations of experiment? The experiment with _____ shall NOT be irradiated in the reactor.

a. Rate of reactivity exceeding 50 pcm/sec

b. Non-secured worth exceeding 300 pcm

c. Experiment with pressure buildup 210 psi

d. Any flammable material

Section B - Normal/Emergency Procedures and Radiological Controls Page 14 QUESTION B.13 [1.0 point]

A system or component is defined as "OPERABLE" by Technical Specifications when:

a. a system is operational when reactor is in the unsecured condition

b. a system is operational when reactor is in the shutdown condition

c. it is capable of performing its intended function

d. a system is recently calibrated QUESTION B.14 [1.0 point]

The MAIN purpose to encapsulate a corrosive material irradiated in the reactor core is to prevent:

a. contamination in the pool water.

b. pressure build up in the sample holder.

c. release of corrosive gas to the reactor bay.

d. contamination to handling tools.

QUESTION B.15 [1.0 point]

The MINIMUM level of management who shall approve all experiment loading and unloading is the:

a. Reactor Director

b. Health Physics in duty

c. RO on duty

d. DSRO

Section B - Normal/Emergency Procedures and Radiological Controls Page 15 QUESTION B.16 [1.0 point]

The NCSU Technical Specifications define that a Reportable Event is the circumstances of the event that the licensee shall make a report by telephone to the NRC Headquarters Operations Center no later than the following working day, followed by a written report, submitted to the NRC Document Control Desk, within 14 days. The below items are listed as a Report Event, EXCEPT:

a. The Over-the Pool RAM indicates 120 mR/hr without alarm during fuel movement.

b. A reactor operator accidently inserts a fuel element into the core while reactor is at 5 W.

c. Fission products are detected in the stack particulate monitor during reactor operation.

d. An uncontrolled reactivity change in reactivity exceeds 0.1 %K/K.

QUESTION B.17 [1.0 point]

The N-16 calibration shall be performed at least:

a. monthly.

b. quarterly.

c. semi-annually.

d. annually.

QUESTION B.18 [1.0 point]

Which ONE of the following changes must be submitted to NRC for approval prior to implementation?

a. Replace a primary cooling pump with identical pump.

b. Add new limitation to the Pre-Startup Checklist Procedure.

c. Add more responsibilities to the Radiation Protection Officer listed in the health physics procedure.

d. Delete a definition of Reactor Shutdown listed in the NCSU Technical Specifications.

Section B - Normal/Emergency Procedures and Radiological Controls Page 16 QUESTION B.19 [1.0 point]

Assume that there is no leak from outside of the demineralizer tank. You use a survey instrument with a window probe to measure the dose rate from the demineralizer tank.

Compare to the reading with a window CLOSED, the reading with a window OPEN will:

(Assume that there is NO contamination from the outside of the demineralizer tank)

a. increase, because it can receive an additional alpha radiation from

[(Al-27) (n,) (Na-24)] reaction.

b. remain the same, because the Quality Factors for gamma and beta radiation are the same.

c. increase, because the Quality Factor for beta and alpha is greater than for gamma.

d. remain the same, because the survey instrument would not be detecting beta and alpha radiation from the demineralizer tank.

QUESTION B.20 [1.0 point]

In the event of a suspected fuel leak, which ONE of the following nuclides would most likely be found in the Stack Particulate Monitor?

a. Ar-41

b. I-133

c. N-16

d. Co-60

- - - - End of Section B ********************************

Section C: Plant and Rad Monitoring Systems Page 17 QUESTION C.01 [1.0 point]

During reactor operation, which ONE of the following best describes on how the amplifier of the Safety Channel (Uncompensated Ion Chamber) works? The amplifier converts ionization signal from:

a. (n,) reaction into a d.c. current then amplifies the d.c. current in a logarithmic manner

b. (n,) reaction into a d.c. current then amplifies the d.c. signal in a logarithmic manner

c. fission fragment into a d.c. current then amplifies the d.c. signal in a logarithmic manner

d. (n,p) reaction into an a.c. current then amplifies the a.c. signal in a logarithmic manner QUESTION C.02 [1.0 point]

Which ONE of the following channels may provide the first indications of a fuel pin failure?

a. N-16 Channel

b. Safety Channel

c. Linear Channel

d. Log and Linear Channel QUESTION C.03 [1.0 point]

Identify the exceeding limit (MAXIMUM or MINIMUM) of the following Limiting Safety System Settings (LSSS) for the forced convection flow.

a. Primary Coolant Flow 450 gpm

b. Pool Water Temperature 117 °F

c. Water Height 14 ft 2

d. Reactor Power 1.3 MWt

Section C: Plant and Rad Monitoring Systems Page 18 QUESTION C.04 [1.0 point]

During the Startup in Forced Convection Mode, you find the actual Shutdown Margin (SDM) is 350 pcm. For this calculation, you will:

a. continue the startup because this SDM is within the limit.

b. continue the startup and get approval from the Designated Senior Reactor Operator.

c. shutdown reactor and immediately notify the result to the Designated Senior Reactor Operator.

d shutdown reactor and immediately report to NRC for TS violation.

QUESTION C.05 [1.0 point]

During a startup checklist for the Stack Gas Monitor, you notice that the flow fault light is NOT on and its annunciator is NOT lit, when the sampling pump is running. These conditions show that the Stack Gas Monitor is in:

a. normal condition.

b. fail mode.

c. test mode.

d. calibration mode.

QUESTION C.06 [1.0 point]

The NCSU reactor fuel shall be UO2 with a nominal enrichment of between:

a. 4% - 6% in U-235, aluminum clad.

b. 4% - 6% in U-235, zircaloy clad.

c. 6% - 8% in U-235, zircaloy clad.

d. 6% - 8% in U-235, stainless steel clad.

Section C: Plant and Rad Monitoring Systems Page 19 QUESTION C.07 [1.0 point]

When a reactor is at 10 kW, you accidently remove the check source out of the reactor core.

This action will cause:

a. Nothing (normal operation)

b. Rod run down

c. Rod withdraw prohibit

d. Scram QUESTION C.08 [1.0 point, 0.25 each]

Reactor is in operation. Match the input signals listed in column A with their AUTOMATIC responses listed in column B. (Items in column B may be used more than once or not at all.)

Column A Column B

a. Pool Resistivity = 1M 1. Normal Operation

b. Loss of Natural Gas Pressure 2. Alarm ONLY

c. West Wall Radiation = 2 mR/hr 3. Interlock

d. Linear Power = 1.3 MW 4. Automatic Scram (with or without Alarm)

QUESTION C.09 [1 point]

During a reactor operation, you discover the Stack Particulate Monitor (SPM) pump has been turned OFF since yesterday. Which ONE of the following actions should you take?

a. Immediately secure reactor. This event is a Technical Specification (TS) violation.

b. Immediately secure reactor, but this event is NOT a TS violation because the SPM is still operable.

c. Continue with reactor operation. Up to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is allowed to run reactor before replacing the Stack Particulate Monitor.

d. Continue with reactor operations. The NCSU Technical Specifications require only RAMs and Stack Gas monitors during reactor operation.

Section C: Plant and Rad Monitoring Systems Page 20 QUESTION C.10 [1.0 point]

Which ONE of the following best describes on how an automatic transfer switch in the Auxiliary Distribution Panel works?

a. This switch is spring loaded to remain in the open position. As the generator comes up to speed and voltage, the generator output voltage works against the spring tension to close the switch and apply power to the Auxiliary Distribution Panel.

b. This switch is controlled by computer system. As the generator comes up to speed and voltage, the computer will sense the power and then switch from OFF to ON, so the power is distributed to the Auxiliary Distribution Panel.

c. This switch is operated by a hydraulic system in the open position. As the generator comes up to speed and voltage, the system will change phase and close the switch, so the power is distributed to the Auxiliary Distribution Panel.

d. This switch is operated by a motor control system in the stand-by position. As the generator comes up to speed and voltage, a motor control system will start and close the switch, so the power is distributed to the Auxiliary Distribution Panel.

QUESTION C.11 [2.0 point, 0.5 each]

Match the following actions used in Column A with their respective definitions in Column B:

COLUMN A COLUMN B

a. You compare readings of Safety Channel 1. Channel Check with Linear Channel during reactor operations

2. Channel Test

b. During startup, you verify the reactor scram at 1.3 MW

3. Channel Calibration

c. During startup, you remove a neutron source to verify rod withdrawal prohibit

d. You adjust a safety channel reading after conducting a thermal power calibration

Section C: Plant and Rad Monitoring Systems Page 21 QUESTION C.12 [1.0 point]

A reactor is at full power. Which ONE of the following methods will reduce the MOST buildup of N-16 in the reactor pool surface?

a. Turn primary pumps OFF, so it increases the amount of time for N-16 staying in the reactor coolant system.

b. Turn primary pumps ON, so it increases the amount of time for N-16 staying in the reactor coolant system.

c. Turn the exhaust fan ON, so N-16 will be exhausted through the stack

d. Turn the intake louvers ON, so N-16 will be diluted with air coming from the building outside.

QUESTION C.13 [1.0 point]

Which ONE of the following is the correct parameter used for the calibration of control rods by positive period method at NCSU? The operator will determine:

a. reactivity vs. rod height

b. reactivity vs. period

c. pool level vs. coolant flow

d. count rate vs. rod height QUESTION C.14 [1.0 point]

The Temperature Measuring Channel measures the water temperature in the Primary and Secondary Coolant. The NCSU Measuring Temperature Channel consists of:

a. a precision wound capacitor which changes capacitive proportional to the change in temperature.

b. a bi-metallic junction which changes voltage proportional to the change in temperature.

c. a sphere containing a liquid which changes volume with temperature. Expansion and contraction cause an arm in an inductor to move changing inductance proportional to the change in temperature.

d. a precision wound resistor which changes resistance proportional to the change in temperature.

Section C: Plant and Rad Monitoring Systems Page 22 QUESTION C.15 [1.0 point]

Which ONE of the following is the NORMAL range for magnet currents of the Safety control rod?

a. 36 - 38 mA

b. 40 - 42 mA

c. 44 - 46 mA

d. 48 -50 mA QUESTION C.16 [1.0 point]

After losing commercial power, you attempt to start the Auxiliary Generator but the cranking limiter contact opens up. To restart the generator you must:

a. place the Start switch to stop than to start.

b. place the Run-Stop-Remote switch in the Run position.

c. place the Auxiliary Distribution Panel switch in the open position.

d. reset the cranking limiter at the Auxiliary Generator control panel.

QUESTION C.17 [1.0 point]

Which ONE of the following will indicate the cleanest pool water?

a. Highest pH

b. Highest resistivity

c. Highest conductivity

d. Lowest pH

Section C: Plant and Rad Monitoring Systems Page 23 QUESTION C.18 [1.0 point]

Which ONE of the following is the method use to get rid of radioactive low-level solid waste at NCSU reactor? Radioactive low-level solid waste is:

a. burned, then dumped to the public trash system.

b. packed, then transferred to the Department of Energy.

c. packed, then transferred to the NCSU University Radiation Safety Division.

d. diluted with water to less than 10CFR20 limits, then pumped to the sanitary sewer system.

QUESTION C.19 The Figure 4.6 depicts the reactor core support structure. Which letter indicates the correct location of Fission Chamber?

a. A

b. B

c. C

d. D

Section C: Plant and Rad Monitoring Systems Page 24

- - - - End of Section C ****************************

- - - - End of the Exam ***************************

Section A L Theory, Thermo & Facility Operating Characteristics Page 25 A.01 Answer: d

Reference:

3-nd generation=n + K*n = K2* n=1000+700+490=2190 neutrons A.03 Answer: c

Reference:

K eff = 1.05*0.80*0.90*0.92*1.86*x X= 1/1.294 = 0.773 A.04 Answer: c

Reference:

Keff1=1/1- 1 Keff1 =1/(1-(-.05)) -->Keff1= 0.952, Count1*(1-Keff1) = Count2*(1-Keff2)

Count1*(1-0.952) = Count2*(1-Keff2) 1000*(1-0.952) = 4000(1- Keff2); Keff2 = 0.988 A.05 Answer: a

Reference:

A.06 Answer: c

Reference:

Reactivity added = 156 pcm = 0.00156 k/k

= (-)/eff = (0.0073 - 0.00156)/ ((0.1)*(0.00156)) = 37 seconds A.07 Answer: d

Reference:

Section A L Theory, Thermo & Facility Operating Characteristics Page 26 A.09 Answer: b

Reference:

SDM = (1- keff)/keff = (1-0.927)/0.927 = 0.07875 k/k. So if you add the same amount of SDM, the reactor is just critical.

Another method: you can find the new value of Keff when adding 0.07875 k/k to reactor.

p = (k2 -k1)/ k1*k2 0.07875 = (k2- 0.927)/(0.927* k2), solve for k2 K2 = 1, hence the reactor is just critical A.10 Answer: d

Reference:

NRC Standard Question A.12 Answer: c

Reference:

A.16 Answer: c

Reference:

Core excess = Total Rod Worth - Rod Worth removed at 5 watts 9000 pcm - 7000 pcm = 2000 pcm

Section A L Theory, Thermo & Facility Operating Characteristics Page 27 A.18 Answer: d

Reference:

= k-1/k = 0.001 Period T = l*/

T = 0.1 /0.001 = 100 A.20 Answer: c

Reference:

Time is related to ratio of final power to initial power. 2:1 is the largest ratio.

Section B Normal, Emergency and Radiological Control Procedures Page 28 B.01 Answer: a

Reference:

HP8, Section 4.1.1 B.02 Answer: b

Reference:

EP 7.5.7 B.03 Answer: a(1) b(1) c(4) d(1)

Reference:

10 CFR 20 B.04 Answer: b

Reference:

DR = DR*e -t 1.25 rem/hr =5 rem/hr* e -(5hr)

Ln(1.25/5) = -*5 --> =0.277; solve for t: Ln(.625/5)=-0.277 *t t=7.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months B.05 Answer: d

Reference:

TS 3.2 All experiment limit = 2890 pcm = 2.890 % k/k > 2000 pcm or 2.0 % k/k B.06 Answer: c

Reference:

TS 3.2 B.07 Answer: a

Reference:

Emergency Plan 2.13 B.08 Answer: b

Reference:

R/hr = 6CE/r2 = 6 x 5 x 1*(1.17+1.33)/ 62 = 2.08 R/hr B.09 Answer: c

Reference:

TS 6.1.3 B.10 Answer: c

Reference:

TS Table 3.3 B.11 Answer: a

Reference:

10 CFR Part 20.1003

Section B Normal, Emergency and Radiological Control Procedures Page 29 B.12 Answer: c

Reference:

TS 3.7 B.13 Answer: c

Reference:

TS 1.2.15 B.14 Answer: a

Reference:

TS 3.7.a B.15 Answer: d

Reference:

NRP-OP-104, section 4.1.1 B.16 Answer: d

Reference:

TS 1.2.24 (less than $1)

B.17 Answer: c

Reference:

TS 4.2 B.18 Answer: d

Reference:

10 CFR 50.59 B.19 Answer: d

Reference:

Basic radiological concept (beta and alpha radiation don't make through the demineralizer tank)

B.20 Answer: b

Reference:

NCSU Training Manual 13.2

Section C Facility and Radiation Monitoring Systems Page 30 C.01 Answer: b

Reference:

SAR 7.2.2 B-10 + n Li-7 + alpha C.02 Answer: a

Reference:

NCSU Training Manual 7.2.5 C.03 Answer: a (MINIMUM) b(MAXIMUM) c(MINIMUM) d(MAXIMUM)

Reference:

TS 2.2 C.04 Answer: c

Reference:

NCSU Training Manual, Section NRP-OP-101 Reactor Startup and Shutdown C.05 Answer: a

Reference:

NRP-OP-101, Appendix B C.06 Answer: b

Reference:

NCSU Training Manual 4.5.3.2.5 and TS 5.1 C.07 Answer: a

Reference:

NCSU Training Manual 7.2.1 C.08 Answer: a(2) b(2) c(1) d(4)

Reference:

NRP-OP-105 C.09 Answer: a

Reference:

TS 3.5 C.10 Answer: a

Reference:

NCSU Training Manual 8.3.4 C.11 Answer: a(1) b(2) c(2) d(3)

Reference:

TS 1.2

Section C Facility and Radiation Monitoring Systems Page 31 C.12 Answer: b

Reference:

NRC Standard Question C.13 Answer: a

Reference:

NCSU Training Manual Figure 3-32 Gang Integral Rod Worth C.14 Answer: d

Reference:

NCSU Training Manual 7.3.4 C.15 Answer: c

Reference:

NCSU Training Manual, Section 7.3.8 C.16 Answer: d

Reference:

NCSU Training Manual, Section 8.3.3 C.17 Answer: b

Reference:

NRC Standard Question C.18 Answer: c

Reference:

NCSU Training Manual, Section 10.1.3 C.19 Answer: b

Reference:

NCSU Training Manual Figure 4-6