ML023090532

Retake Examination Report No. 50-297/OL-03-01, North Carolina State Univ

ML023090532
Person / Time
Site:	North Carolina State University
Issue date:	11/13/2002
From:	Madden P NRC/NRR/DRIP/RORP
To:	Fox M North Carolina State University
Doyle P, NRC/NRR/DRIP/RORP, 415-1058
Shared Package
ML022730656	List: ML022730683 ML023090532 ML023100127
References
50-297/OL-03-01 50-297/OL-03-01
Download: ML023090532 (19)

Text

November 13, 2002 Dr. Marye Anne Fox, Chancellor Room A Holladay Hall North Carolina State University Post Office Box 7001 Raleigh, NC 27695-7001

SUBJECT:

RETAKE EXAMINATION REPORT NO. 50-297/OL-03-01, NORTH CAROLINA STATE UNIVERSITY

Dear Dr. Fox:

On October 30, 2002, the NRC administered an operator licensing examination at your North Carolina State University Reactor. The examination was conducted according to NUREG-1478, "Non-Power Reactor Operator Licensing Examiner Standards," Revision 1.

In accordance with 10 CFR 2.790 of the Commissions 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 (PARS) component of NRCs document system (ADAMS). ADAMS is accessible from the NRC Web site at (the Public Electronic Reading Room) http://www.nrc.gov/NRC/ADAMS/indesx.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 Paul Doyle at (301) 415-1058 or via internet E-mail at pvd@nrc.gov.

Sincerely,

/RA/

Patrick M. Madden, Section Chief Research and Test Reactors Section Operating Reactor Improvements Program Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Docket No. 50-297

Enclosures:

1. Retake Examination Report No. 50-297/OL-03-01

2. Examination and answer key (Corrected) cc w/encls:

Please see next page

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

Office of Intergovernmental Relations 116 West Jones Street Raleigh, NC 27603 Dr. Paul J. Turinsky, Head Nuclear Engineering Department North Carolina State University P.O. Box 7909 Raleigh, NC 27695-7909 Dayne H. Brown, Director Division of Radiation Protection Department of Environmental, Health and Natural Resources P.O. Box 27687 Raleigh, NC 27611-7687 Dr. Nino A. Masnari Dean of Engineering North Carolina State University P.O. Box 7909 Raleigh, NC 27695-7909 Test, Research, and Training Reactor Newsletter University of Florida 202 Nuclear Sciences Center Gainesville, FL 32611

November 13, 2002 Dr. Marye Anne Fox, Chancellor Room A Holladay Hall North Carolina State University Post Office Box 7001 Raleigh, NC 27695-7001

SUBJECT:

RETAKE EXAMINATION REPORT NO. 50-297/OL-03-01, NORTH CAROLINA STATE UNIVERSITY

Dear Dr. Fox:

On October 30, 2002, the NRC administered an operator licensing examination at your North Carolina State University Reactor. The examination was conducted according to NUREG-1478, "Non-Power Reactor Operator Licensing Examiner Standards," Revision 1.

In accordance with 10 CFR 2.790 of the Commissions 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 (PARS) component of NRCs document system (ADAMS). ADAMS is accessible from the NRC Web site at (the Public Electronic Reading Room) http://www.nrc.gov/NRC/ADAMS/indesx.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 Paul Doyle at (301) 415-1058 or via internet E-mail at pvd@nrc.gov.

Sincerely,

/RA/

Patrick M. Madden, Section Chief Research and Test Reactors Section Operating Reactor Improvements Program Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Docket No. 50-297

Enclosures:

1. Retake Examination Report No. 50-297/OL-03-01

2. Examination and answer key (Corrected) cc w/encls:

Please see next page DISTRIBUTION w/ encls.:

PUBLIC RORP\R&TR r/f PMadden DHughes Facility File (EBarnhill) O-6 D-17 ADAMS ACCESSION #: ML023090532 TEMPLATE #:NRR-074 OFFICE RORP:CE IEHB:LA E RORP:SC NAME PDoyle:rdr EBarnhill PMadden DATE 11/ 06 / 2002 11/ 06 /2002 11/ 07 /2002 C = COVER E = COVER & ENCLOSURE N = NO COPY

OFFICIAL RECORD COPY U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.: 50-297/OL-03-01 FACILITY DOCKET NO.: 50-297 FACILITY LICENSE NO.: R-120 FACILITY: North Carolina State University EXAMINATION DATES: October 30, 2002 SUBMITTED BY: ___________/RA/________________ 11/5/2002 Paul Doyle, Chief Examiner Date

SUMMARY

On October 30, 2002, North Carolina State University staff administered an NRC prepared operator licensing retake examination to one Reactor Operator candidate. The candidate passed the written examination.

REPORT DETAILS

1. Examiners:

Paul Doyle, Chief Examiner

2. Results:

RO PASS/FAIL SRO PASS/FAIL TOTAL PASS/FAIL Written 1/0 0/0 1/0 Operating Tests 0/0 0/0 0/0 Overall 1/0 0/0 1/0

3. Exit Meeting:

NONE ENCLOSURE 1

NORTH CAROLINA STATE UNIVERSITY With Answer Key OPERATOR LICENSING EXAMINATION Section A ONLY ENCLOSURE 2

Section A / Theory, Thermo & Fac. Operating Characteristics Page 1 QUESTION A.1 [2.0 points, 1/2 each]

Match each term in column A with the correct definition in column B.

Column A Column B

a. Prompt Neutron 1. A neutron in equilibrium with its surroundings.

b. Fast Neutron 2. A neutron born directly from fission.

c. Thermal Neutron 3. A neutron born due to decay of a fission product.

d. Delayed Neutron 4. A neutron at an energy level greater than its surroundings.

QUESTION A.2 [1.0 point]

During a Critical Experiment "1/M" data is required to be taken. What does the 1/M represent?

a. The inverse of the moderator coefficient of reactivity.

b. The inverse of core total U235 mass.

c. The inverse migration length of neutrons of varying energies.

d. The inverse multiplication of the count rate between generations.

QUESTION A.3 [1.0 point]

Which of the following statements correctly describe the influence of DELAYED NEUTRONS on the neutron life cycle? Delayed neutrons

a. increase the time required for PU239 to moderate the fission process.

b. decrease the time required for the neutron population to change between generations.

c. increase the time required for the neutron population to change between generations.

d. decrease the amount of reflection possible with a steel reflector.

QUESTION A.4 [1.0 point]

Initially a reactor is subcritical with a Keff of 0.96 and Nuclear instrumentation indicates 30 counts per second.

A fuel element is removed and count rate drops to 10 counts per second. Assuming no other reactivity changes to the core, which ONE of the following is the new Keff of the core?

a. 0.9733

b. 0.8800

c. 0.8433

d. 0.8000

Section A / Theory, Thermo & Fac. Operating Characteristics Page 2 QUESTION A.5 [1.0 point]

Which ONE of the following is an example of beta plus ( +)decay?

a. 35 Br87 33As83

b. 35 Br87 35Br86

c. 35 Br87 34Se87

d. 35 Br87 36Kr87 QUESTION A.6 [1.0 point]

What is the period that would cause reactor power to double in 40 seconds?

a. 3.7 seconds

b. 27.7 seconds

c. 57.7 seconds

d. 80.0 seconds QUESTION A.7 [1.0 point]

Reactor power is at 1 watt with a +30 second stable period. How long will it take to increase power to 500 watts?

a. 186 seconds

b. 140 seconds

c. 124 seconds

d. 81 seconds QUESTION A.8 [1.0 point]

Which one of the following accurately describes a factor contributing to Xenon balance within the reactor?

a. Most Xe135 is formed by fission.

b. Te135 is a fission product which quickly decays to I135.

c. Within approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after startup, Xe135 has reached its equilibrium value.

d. Several minutes following a reactor shutdown, Xe135 level is increasing because I135 is not being produced.

Section A / Theory, Thermo & Fac. Operating Characteristics Page 3 QUESTION A.9 [1.0 point]

Delayed neutrons comprise approximately what percent of all neutrons produced in the reactor?

a. 0.65%

b. 1.3%

c. 6.5%

d. 13%

QUESTION A.10 [1.0 point]

Given the following data, which ONE of the following is the closest to the half life of the material?

TIME ACTIVITY 0 2400 cps 10 min. 1757 cps 20 min. 1286 cps 30 min. 941 cps 60 min. 369 cps

a. 11 minutes

b. 22 minutes

c. 44 minutes

d. 51 minutes QUESTION A.11 [1.0 point]

Which ONE of the following IS CORRECT with regard to criticality?

a. Critical rod height does NOT depend on how fast control rods are withdrawn.

b. Critical rod height dictates the reactor power level when criticality is first achieved.

c. The slower the approach to criticality, the lower the reactor power level will be when reaching criticality.

d. The reactivity of the reactor increases towards infinity during the approach to criticality.

QUESTION A.12 [1.0 point]

Which ONE of the following describes a property of a GOOD MODERATOR?

a. It slows down fast neutrons to thermal energy levels via a small number of collisions

b. It reduces gamma radiation to thermal energy levels via a small number of collisions

c. It slows down fast neutrons to thermal energy levels via a large number of collisions

d. It reduces gamma radiation to thermal energy levels via a large number of collisions

Section A / Theory, Thermo & Fac. Operating Characteristics Page 4 QUESTION A.13 [1.0 point]

What is the PRINCIPAL source of heat in the reactor after shutdown?

a. Cosmic radiation causing fission

b. Decay of fission products

c. Spontaneous fission within the core

d. Stored energy from the reactor and core materials QUESTION A.14 [1.0 point]

and eff both describe the total fraction of delayed neutrons. The difference between the two is that eff is

a. smaller than since delayed neutrons are born at lower energy levels than prompt neutrons.

b. larger than since delayed neutrons are born at lower energy levels than prompt neutrons.

c. smaller than since delayed neutrons are born at higher energy levels than prompt neutrons.

d. larger than since delayed neutrons are born at higher energy levels than prompt neutrons.

QUESTION A.15 [1.0 point]

Several processes occur that may increase or decrease the available number of neutrons. SELECT from the following the six-factor formula term that describes an INCREASE in the number of neutrons during the cycle.

a. Thermal utilization factor (f).

b. Resonance escape probability (p).

c. Thermal non-leakage probability (üth).

d. Reproduction factor ( ).

QUESTION A.16 [1.0 point]

You perform a heat balance with the following parameters. Primary flow was 505 gal/min, the T across the primary side of the heat exchanger was 13.5EF, and the pool had a COOLDOWN RATE of 3EF/hr. Which ONE of the following is the calculated Power? Constants: cP = 0.998 BTU/HrEF, 1 gallon of water =

8.272 lbm, and Volume of the pool = 15650 gallons.

a. 0.876 Mw

b. 0.989 Mw

c. 1.046 Mw

d. 1.103 Mw

Section A / Theory, Thermo & Fac. Operating Characteristics Page 5 QUESTION A.17 [1.0 point]

Given an ACP of 19.0 inches with average temperature at 70EF and Xenon free. Calculate the ECP with average temperature = 95.0EF and Xenon adding -200 pcm reactivity. Use the Gang Integral Rod Worth curve given in the handout. The source is in for both, and no changes in experiments.

a. 18.8 inches

b. 19.4 inches

c. 19.6 inches

d. 20.1 inches QUESTION A.18 [1.0 point]

Which one of the following factors is most easily varied by the reactor operator?

a. reproduction factor

b. fast fission factor

c. fast non-leakage probability

d. thermal utilization factor QUESTION A.19 [1.0 point]

Why is the stable negative period following a scram always the same value, regardless of initial power level?

The rate of power change is dependent on the

a. mean lifetime of the longest lived neutron delayed precursor.

b. constant decay rate of prompt neutrons.

c. mean lifetime of the shortest lived delayed neutron precursor.

d. constant decay rate of prompt gamma emitters.

Section A / Theory, Thermo & Fac. Operating Characteristics Page 6 A.1 a, 2; b, 4; c, 1; d, 3 REF: Pulstar Reactor Trainee Notebook, Chapter 2, § 2.2 and Chapter 1, § 1.4.4 ¶¶ 5 and 7.

A.2 d REF: Pulstar Reactor Trainee Notebook, Chapter 1, Reactor Theory Handout equation 1.33.

A.3 c REF: Pulstar Reactor Trainee Notebook, Chapter 2, § 2.3.

A.4 b CR1/CR2 = [1 - Keff2]/[1 - Keff1] 30/10 = [1 - Keff]/[1 - 0.96] 1 - Keff = 3 x 0.04 = 0.12 Keff = 0.88 REF: Pulstar Reactor Trainee Notebook, Equation Sheet.

A.5 c REF: Standard NRC question A.6 c REF: P = P0 eT/ , since P = 2P0 then ln(2) = 40sec/ = 40sec/ln(2) = 57.7 sec A.7 a REF: ln (P/P0) x period = time, ln(500) x 30 = 6.215 x 30 = 186.4 . 186 seconds A.8 b REF: Pulstar Reactor Trainee Notebook, Chapter 2, § 2.9.3.1.

A.9 a REF: Pulstar Reactor Trainee Notebook, Chapter 2, § 2.2, p. 4.

A.10 b REF: I = I0 e-t/ Ln(369/2400) = 60min/ = 60min/[ln(369/2400)] = 32.044 min-1. t1/2 = ln(2) x = -22.211 A.11 a REF: Pulstar Reactor Trainee Notebook, Chapter 1, § 1.5.3, p. 19.

A.12 a REF: Standard NRC question.

A.13 b REF: Pulstar Reactor Trainee Notebook, Chapter 1, page 5.

A.14 b REF: Pulstar Reactor Trainee Notebook, Chapter 2, § 2.3.

A.15 d REF: Pulstar Reactor Trainee Notebook, Six Factor Formula handout.

A.16 a REF: Pulstar Reactor Trainee Notebook, Chapter 3 Example 8.1.

A.17 d +25EF x -3.9pcm/EF = -97.5pcm + (-200pcm) = -297.5 pcm. On graph adding +297.5 would change rod position from 19.0 inches to 20.1 inches.

REF: Pulstar Reactor Trainee Notebook, Chapter 2 § 2.11.

Section A / Theory, Thermo & Fac. Operating Characteristics Page 7 A.18 d REF: Pulstar Reactor Trainee Notebook, Chapter 2 § 2.11.x A.19 a REF: Pulstar Reactor Trainee Notebook, Chapter 2 § 2.11.x

U. S. NUCLEAR REGULATORY COMMISSION RESEARCH AND TEST REACTOR OPERATOR LICENSING EXAMINATION FACILITY: North Carolina State University REACTOR TYPE: PULSTAR DATE ADMINISTERED: 2002/10/30 CANDIDATE:

INSTRUCTIONS TO CANDIDATE:

Answers are to be written on the answer sheets provided. Points for each question are indicated in brackets for each question. You must score 70% to pass. Examinations will be picked up one (1) hour after the examination starts.

% of Category % of Candidates Category Value Total Score Value Category 20.00 33.3 A. Reactor Theory, Thermodynamics and Facility Operating Characteristics 20.00  % TOTALS FINAL GRADE All work done on this examination is my own. I have neither given nor received aid.

Candidates 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 proctor 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.

12. There is a time limit of one (1) hour for completion of the examination.

13. When you have completed and turned in you examination, leave the examination area. If you are observed in this area while the examination is still in progress, your license may be denied or revoked.

EQUATION SHEET



Q0 ' mc0 p T ' m0 H ' UA ( & )2 T Pmax ' R( ' 3 x 10&5 seconds 2 (k)R eff ' 0.1 seconds &1 SCR (Neq) '

S S

CR1(1&Keff ) ' CR2(1&Keff )

& 1&Keff 1 2 CR1(& 1) ' CR2(& 2) eff 26.06 UR ' 26.06 ' 1&Keff 1 CR1 eff& M ' 0 M ' '

1&Keff1 1&Keff CR2 P ' P0 10SUR(t) t (1& )

P ' P0 e P ' P0 (1&Keff) R( R( -&

SDM ' ' '  %

Keff & - eff Keff & Keff 0.693 (Keff&1)

' 2 1 T1/2 ' '

keff1xKeff2 Keff 6CiE(n) DR1d12 ' DR2d22 DR '

DR 'DR0 e & t R2 DR - Rem, Ci - curies, E - Mev, R - feet

( 2& ) 2 ( 1& ) 2 Peak2 Peak1



1 Curie = 3.7 x 1010 dis/sec 1 kg = 2.21 lbm 1 Horsepower = 2.54 x 103 BTU/hr 1 Mw = 3.413 x 106 BTU/hr 1 BTU = 778 ft-lbf EF = 9/5 EC + 32 1 gal (H2O) . 8.272 lbm EC = 5/9 (EF - 32) cP = 0.998 BTU/hr/lbm/EF cp = 0.998 cal/sec/gm/EC T = -3.9 pcm/EF Pool Volume = 15650 gallons

Section A / Theory, Thermo, and Facility Characteristics A.1a 1 2 3 4 ___ A.9 a b c d ___

A.1b 1 2 3 4 ___ A.10 a b c d ___

A.1c 1 2 3 4 ___ A.11 a b c d ___

A.1d 1 2 3 4 ___ A.12 a b c d ___

A.2 a b c d ___ A.13 a b c d ___

A.3 a b c d ___ A.14 a b c d ___

A.4 a b c d ___ A.15 a b c d ___

A.5 a b c d ___ A.16 a b c d ___

A.6 a b c d ___ A.17 a b c d ___

A.7 a b c d ___ A.18 a b c d ___

A.8 a b c d ___ A.19 a b c d ___

Question A.16 Heat Balance 505 gal/min X 8.272 lbm/gal X 60 min/hr X 0.998 BTU/lbm°F X 13.5 ºF = 3376894.3 BTU/hr 15650 gal X 8.272 lbm/gal X 0.998 BTU/lbm°F X -3 ºF/hr -387593.7 BTU/hr 2989300.6 BTU/hr Correct answer: 0.8758572Mw Flow rate only: 0.9894211Mw Pool Cooldown Only: -0.113564Mw Sign error (Heatup instead of cooldown): 1.102985Mw