ML15042A113

Examination Report No. 50-123/OL-15-02, Missouri University of Science and Technology

ML15042A113
Person / Time
Site:	University of Missouri-Rolla
Issue date:	03/13/2015
From:	Kevin Hsueh Research and Test Reactors Licensing Branch
To:	Lee H Missouri Univ of Science & Technology
Young, Phillip 415-4094
Shared Package
ML15030A182	List: ML15042A113 ML15042A525
References
50-123/15-002 50-123/OL-15
Download: ML15042A113 (14)

Text

March 13, 2015 Dr. Hyoung K. Lee, Reactor Facility Director Missouri University of Science and Technology Nuclear Engineering 222 Fulton Hall Rolla, MO 65409-0170

SUBJECT:

EXAMINATION REPORT NO. 50-123/OL-15-02, MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY

Dear Dr. Lee:

During the week of February 2, 2015, the NRC administered an operator licensing examination at your Missouri University of Science and Technology Reactor. The examination was conducted according to NUREG-1478, "Operator Licensing Examiner Standards for Research and Test Reactors," Revision 2.

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 (PARS) component of NRC's 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 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 Mr. Phillip T.

Young at 301-415-4094 or via e-mail Phillip.Young@nrc.gov.

Sincerely,

/RA/

Kevin Hsueh, Chief Research and Test Reactors Oversight Branch Division of Policy and Rulemaking Office of Nuclear Reactor Regulation Docket No. 50-123

Enclosures:

1. Initial Examination Report No. 50-123/OL-15-02

2. Written Examination cc w/o encl: see next page

ML15042A113 NRR-074 OFFICE NRR/DPR/PROB NRR/DPR/PROB NRR/DPR/PROB NAME PYoung/pty CRevelle KHsueh DATE 02/10/2015 02/27/2015 03/13/2015 University of Missouri - Rolla Docket No. 50-123 cc:

Homeland Security Coordinator Craig Reisner Missouri Office of Homeland Security University of Missoure-Rolla P.O. Box 749 Nuclear Reactor Facility Jefferson City, MO 65102 1870 Miner Circle Rolla, MO 65409-0630 Planner, Dept of Health and Senior Services Section for Environmental Public Health 930 Wildwood Drive, P.O. Box 570 Jefferson City, MO 65102-0570 Deputy Director for Policy Department of Natural Resources 1101 Riverside Drive Fourth Floor East Jefferson City, MO 65101 A-95 Coordinator Division of Planning Office of Administration P.O. Box 809 State Capitol Building Jefferson City, MO 65101 Test, Research, and Training Reactor Newsletter University of Florida 202 Nuclear Sciences Center Gainesville, FL 32611 Dr. Samuel Frimpong, Chair Mining and Nuclear Engineering 226 McNutt Hall Missouri University of Science and Technology Rolla, MO 65409-0450

ENCLOSURE 1 U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.:

50-123/OL-15-02 FACILITY DOCKET NO.:

50-123 FACILITY LICENSE NO.:

R-79 FACILITY:

Missouri University of Science and Technology EXAMINATION DATES:

February 2, 2015 SUBMITTED BY:

Phillip T. Young, Chief Examiner Date

SUMMARY

During the week of February 2, 2015 the NRC administered operator licensing examinations to two retake Reactor Operator applicants. Both retake applicants passed the examinations.

REPORT DETAILS

1. Examiners:

Phillip T. Young, Chief Examiner, NRC Paulette Torres, Examiner Trainee, NRC

2. Results:

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

0/0 0/0 Overall 2/0 0/0 2/0

3. Exit Meeting:

This was a retake examination, no exit was conducted.

ENCLOSURE 2 U. S. NUCLEAR REGULATORY COMMISSION NON-POWER INITIAL REACTOR LICENSE EXAMINATION FACILITY:

Missouri University of Science and Technology (Rolla)

REACTOR TYPE:

MTR DATE ADMINISTERED:

2/02/2015 CANDIDATE:

INSTRUCTIONS TO CANDIDATE:

Answers are to be written on the answer sheet provided. Attach the answer sheets to the examination. Points for each question are indicated in brackets for each question. A 70% in each section is required to pass the examination. Examinations will be picked up three (3) hours after the examination starts.

% of Category % of Candidates Category Value Total Score Value Category 18.0 33.3 A. Reactor Theory, Thermodynamics and Facility Operating Characteristics 18.0 TOTALS FINAL GRADE All work done on this examination is my own. I have neither given nor received aid.

Candidate's Signature

NRC RULES AND GUIDELINES FOR LICENSE EXAMINATIONS During the administration of this examination the following rules apply:

1. Cheating on the examination means an automatic denial of your application and could result in more severe penalties.

2. After the examination has been completed, you must sign the statement on the cover sheet indicating that the work is your own and you have neither received nor given assistance in completing the examination. This must be done after you complete the examination.

3. Restroom trips are to be limited and only one candidate at a time may leave. You must avoid all contacts with anyone outside the examination room to avoid even the appearance or possibility of cheating.

4. Use black ink or dark pencil only to facilitate legible reproductions.

5. Print your name in the blank provided in the upper right-hand corner of the examination cover sheet and each answer sheet.

6. Mark your answers on the answer sheet provided. USE ONLY THE PAPER PROVIDED AND DO NOT WRITE ON THE BACK SIDE OF THE PAGE.

7. The point value for each question is indicated in [brackets] after the question.

8. If the intent of a question is unclear, ask questions of the examiner only.

9. When turning in your examination, assemble the completed examination with examination questions, examination aids and answer sheets. In addition turn in all scrap paper.

10. Ensure all information you wish to have evaluated as part of your answer is on your answer sheet. Scrap paper will be disposed of immediately following the examination.

11. To pass the examination you must achieve a grade of 70 percent or greater in each category.

12. There is a time limit of three (3) hours 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 SHEETs DR - Rem, Ci - curies, E - Mev, R - feet Peak

)

(

=

Peak

)

(

1 1

2 2

2 2

1 Curie = 3.7 x 1010 dis/sec 1 kg = 2.21 lbm 1 Horsepower = 2.54 x 103 BTU/hr 1 Mw = 3.41 x 106 BTU/hr 1 BTU = 778 ft-lbf EF = 9/5 EC + 32 1 gal (H2O). 8 lbm EC = 5/9 (EF - 32) cP = 1.0 BTU/hr/lbm/EF cp = 1 cal/sec/gm/EC T

UA

=

H m

=

T c

m

=

Q p

K 1

S S

=

SCR eff

)

(-

CR

=

)

(-

CR

)

K (1

CR

=

)

K (1

CR 2

2 1

1 eff 2

eff 1

2 1

seconds 0.1

=

-1 eff

26.06

=

SUR eff K

1 K

1

=

M eff eff 1

0 CR CR

=

K 1

1

=

M 2

1 eff e

P

=

P t

0 P

)

(1

=

P 0

10 P

=

P SUR(t) 0 K

)

K (1

=

SDM eff eff

=

eff

+

=

K 1)

K

(

=

eff eff

K x

k K

K

=

eff eff eff eff 2

1 1

2

0.693

=

T e

DR

=

DR t

0 R

6CiE(n)

=

DR 2

d DR

=

d DR 2

2 2

1 2

1

Section A Reactor Theory, Thermo, and Facility Characteristics Question A.001

[1.0 point]

(1.0)

After a week of full power operation, Xenon will reach its peak following a shutdown in approximately:

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

b. 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />

c. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />

d. 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> Answer:

A.01

b.

Reference:

Burn, R., Introduction to Nuclear Reactor Operations, © 1988, § Question A.002

[1.0 point]

(2.0)

Which ONE of the following is the MAIN reason for operating with thermal neutrons instead of fast neutrons?

a. Increased neutron efficiency since thermal neutrons are less likely to leak out of the core than fast neutrons.

b. Neutron absorption in non fuel material increases exponentially as neutron energy increases.

c. The fission cross section of the fuel is much higher for thermal energy neutrons than fast neutrons.

d. Moderator temperature coefficient becomes positive as neutron energy increases.

Answer:

A.02

c.

Reference:

Burn, R., Introduction of Nuclear Reactor Operations, © 1982, Figure 2.6, page 2-39 Question A.003

[1.0 point]

(3.0)

A thermal neutron is a neutron which:

a. is produced as a result of thermal fission.

b. possesses thermal rather than kinetic energy.

c. has been produced several seconds after its initiating fission occurred.

d. experiences no net change in its energy after several collisions with atoms of the diffusing medium.

Answer:

A.03

d.

Reference:

Burn, Introduction to Nuclear Reactor Operations, Pages 2-36, 2-45.

Section A Reactor Theory, Thermo, and Facility Characteristics Question A.004

[1.0 point]

(4.0)

Which ONE of the following factors in the six-factor formula is the simplest to vary by the operator?

a. reproduction factor.

b. thermal utilization factor.

c. thermal non-leakage factor.

d. resonance escape probability.

Answer:

A.04

b.

Reference:

Burn, Introduction to Nuclear Reactor Operations, Page 3-19.

Question A.005

[1.0 point]

(5.0)

About two minutes following a reactor scram, period has stabilized, and is decreasing at a CONSTANT rate. If reactor power is 10-5% full power what will the power be in three minutes.

a. 5 x 10-6 % full power

b. 2 x 10-6 % full power

c. 10-6 % full power

d. 5 x 10-7 % full power Answer:

A.05

c.

Reference:

P = P0 e-T/ = 10-5 x e(-180sec/80sec) = 10-5 x e-2.25 = 0.1054 x 10-5

= 1.054 x 10-6 Question A.006

[1.0 point]

(6.0)

An experiment to be placed in the central thimble has been wrapped in cadmium. Which one of the following types of radiation will be most effectively blocked by the cadmium wrapping?

a. Thermal neutrons

b. Fast neutrons

c. Gamma rays

d. X-rays Answer:

A.06

a.

Reference:

NRC Standard Question.

Section A Reactor Theory, Thermo, and Facility Characteristics Question A.007

[1.0 point]

(7.0)

Which ONE of the following is the MOST affected factor in the six factor formula due to fuel burnup?

a. Fast fission factor.

b. Reproduction factor.

c. Thermal utilization factor.

d. Resonance escape probability.

Answer:

A.07

c.

Reference:

Burn, R., Introduction to Nuclear Reactor Operations, © 1982, Sec 3.2.2, page 3-18.

Question A.008

[1.0 point]

(8.0)

The injection of a sample results in a 50 millisecond period. If the scram setpoint is 300 KILOWATTS and the scram delay time is 0.1 seconds, which ONE of the following is the peak power of the reactor at shutdown?

a. 250 kW

b. 600 kW

c. 900 kW

d. 2200 kW Answer:

A.08

d.

Reference:

Burn, R., Introduction to Nuclear Reactor Operations, © 1982, P = P0 et/, P = 300 kilowatts x e0.1/0.05 = 300 x e2 = 2216.7 kilowatts Question A.009

[1.0 point]

(9.0)

In a just critical reactor, adding one dollar worth of reactivity will cause:

a. A sudden drop in neutron flux.

b. The reactor period to be equal to (-)/.

c. All prompt neutron term to become unimportant.

d. The resultant period to be a function of the prompt neutron lifetime.

Answer:

A.09

d.

Reference:

Introduction to Nuclear Operation, Reed Burn, 1988, Sec 4.2, page 4-4

Section A Reactor Theory, Thermo, and Facility Characteristics Question A.010

[1.0 point]

(10.0)

The RESONANCE ESCAPE PROBABILITY is defined as a ratio of:

a. the number of thermal neutrons absorbed in fuel over the number of thermal neutrons absorbed in fuel and core materials.

b. the number of fast neutrons produced by fission in a generation over the number of total neutrons produced by fission in the previous generation.

c. the number of fast neutrons produced by U-238 over the number of thermal neutrons absorbed in fuel.

d. the number of neutrons that reach thermal energy over the number of fast neutrons that start to slow down.

Answer:

A.10

d.

Reference:

Burn, R., Introduction to Nuclear Reactor Operations, © 1982, Sec 3.3.1, page 3-16.

Question A.011

[1.0 point]

(11.0)

Which ONE of the following statements is the definition of REACTIVITY?

a. A measure of the core's fuel depletion.

b. Equal to 1.00 K/K when the reactor is critical.

c. The factional change in neutron population between generations.

d. The number of neutrons produced by fission in a generation over the number of neutrons produced by fission in the previous generation.

Answer:

A.11

c.

Reference:

Burn, R., Introduction to Nuclear Reactor Operations, © 1982, Sec 3.3.3, page 3-20.

Question A.012

[1.0 point]

(12.0)

A reactor has an effective delayed fraction (eff ) of 0.0065. If a control rod withdrawal in this reactor increases the effective multiplication (keff ) from 0.998 to 1.005, the reactor is:

a. subcritical.

b. exactly critical.

c.

supercritical.

d. prompt critical.

Answer:

A.12

c.

Reference:

Burn, R., Introduction to Nuclear Reactor Operations, © 1982, Section 4.2, Page 4-1.

Note: For prompt critical, keff has to be 1.0065

Section A Reactor Theory, Thermo, and Facility Characteristics Question A.013

[1.0 point]

(13.0)

A reactor is SHUTDOWN by 8.6 % k/k. When a control rod with a worth of -3.1 % k/k is removed from the core, a rate of 1000 counts per second (cps) is measured. What was the previous count rate (cps)? Given eff = 0.0078.

a. 660.

b. 750.

c. 850.

d. 1170.

Answer:

A.13

a.

Reference:

1=-0.086; Keff1=1/1-1 Keff1 =1/(1-(-.086)) -->Keff1= 0.9208, Remove 3.1 % k/k from the core, means adding 3.1 % k/k to the core when removing the rod; new worth = -0.086 + 0.031= -0.055, Keff2 = 1/1+0.055; -->0.948 Count1*(1-Keff1) = Count2*(1-Keff2) Count1*(1-0.9208) = Count2*(1-0.948)

Count1*(1-0.9208) = 1000(1-0.948); Count 1 = 657 cps Question A.014

[1.0 point]

(14.0)

Given the following:

excess = 0.60% k/k, control rod 1 = 0.30% k/k control rod 2 = 0.45% k/k, control rod 3 = 0.50% k/k Calculate the TECHNICAL SPECIFICATION LIMIT for Shutdown Margin for this core.

a. 0.15% k/k

b. 0.65% k/k

c. 1.25% k/k

d. 1.75% k/k Answer:

A.14

a.

Reference:

Total rod worth - (excess + most active control rod)

(0.30+0.45+0.5) %k/k -(0.6+0.5) %k/k =(1.25 -1.1) %k/k = 0.15 %k/k

Section A Reactor Theory, Thermo, and Facility Characteristics Question A.015

[1.0 point]

(15.0)

Which ONE of the following conditions will INCREASE the shutdown margin of a reactor?

a. Lowering moderator temperature (Assume negative temperature coefficient).

b. Insertion of a positive reactivity worth experiment.

c. Burnout of a burnable poison.

d. Fuel depletion.

Answer:

A.15

d.

Reference:

Standard NRC question Question A.016

[1.0 point]

(16.0)

Which ONE of the following is the MAJOR source of energy released during SHUTDOWN?

a. Energy of prompt gamma rays.

b.

Energy of the decayed fission fragments.

c. Kinetic energy of the fission neutrons.

d. Kinetic energy of the fission fragments.

Answer:

A.16

b.

Reference:

Introduction to Nuclear Operation, Reed Burn, 1988, Sec 3.2, page 3-5 Question A.017

[1.0 point]

(17.0)

Which of the following statements is true about Xenon following a reactor scram?

a. The concentration of 135 Xe will decrease due to reduced nuclear flux

b. The concentration of 135 Xe will decrease by natural decay into 135 I

c. The concentration of 135 Xe will increase due to the decay of the 135 I inventory.

d. The concentration of 135 Xe will remain constant until it is removed via neutron burnout during the subsequent reactor startup.

Answer:

A.17

c.

Reference:

Following a reactor shutdown, xenon-135 concentration will increase due to the decay of the iodine inventory of the core.

DOE Handbook, Vol. 2, Section 4

Section A Reactor Theory, Thermo, and Facility Characteristics Question A.018

[1.0 point]

(18.0)

Given the following Core Reactivity Data:

Control Rod Total Worth

(%dk/k)

Worth Removed

(%dk/k)

Safety Rod 1 2.70 1.68 Safety Rod 2 3.20 2.60 Safety Rod 3 2.60 1.52 Regulating Rod 0.40 0.40 Which one of the following is the calculated shutdown margin that would satisfy the Technical Specification Minimum Shutdown Margin? Assume that all control rods are scramable.

a. 2.70

b. 3.00

c. 5.70

d. 6.20 Answer:

A.18

b.

Reference:

SDM = 3(B) - Max. (A) = 6.20%dk/k - 3.20%dk/k = 3.00 %dk/k