Text

Examination Report No. 50-184/OL-23-02, National Institute of Standards and Technology
	ML23257A198
Person / Time
Site:	National Bureau of Standards Reactor
Issue date:	12/26/2023
From:	Travis Tate; NRC/NRR/DANU/UNPO
To:	Adams J; US Dept of Commerce, National Institute of Standards & Technology (NIST)
References
	50-184/23-02 50-184/OL-23
	Download: ML23257A198 (40)
	v • d • e

December 21, 2023 Dr. James Adams, Acting Director National Institute of Standards and Technology NIST Center for Neutron Research U.S Department of Commerce 100 Bureau Drive, Mail Stop 6100 Gaithersburg, MD 20899-6100

SUBJECT:

EXAMINATION REPORT NO. 50-184/OL-23-02, NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY

Dear Dr. Adams:

During the week of July 31, 2023, the U.S. Nuclear Regulatory Commission (NRC) administered an operator licensing examination at your National Institute of Standards and Technology 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 those members of your staff identified in the enclosed report at the conclusion of the examination.

In accordance with Title 10 of the Code of Federal Regulations, Section 2.390, a copy of this letter and the enclosures will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records component of NRC's Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible from the NRC website at http://www.nrc.gov/reading-rm/adams.html. The NRC is forwarding the individual grades to you in a separate letter which will not be released publicly. Should you have any questions concerning this examination, please contact Amy Beasten at 301-415-8341 or via email at Amy.Beasten@nrc.gov.

Sincerely, Signed by Tate, Travis on 12/21/23 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. 50-184

Enclosures:

1. Examination Report No. 50-184/OL-23-02

2. Written examination cc: w/enclosures to GovDelivery Subscribers

ML23257A198 NRR-079 OFFICE NRR/DANU/UNPO/CE NRR/DANU/UNPO/CE NRR/DANU/UNPO/OLA NRR/DANU/UNPO/BC NAME ABeasten MDeSouza NJones TTate DATE 12/21/2023 12/21/2023 12/21/2023 12/21/2023 U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.: 50-184/OL-23-02 FACILITY DOCKET NO.: 50-184 FACILITY LICENSE NO.: TR-5 FACILITY: National Institute of Standards and Technology EXAMINATION DATES: July 31-August 4, 2023 SUBMITTED BY: _Amy E. Beasten 12/21/2023 Amy E. Beasten, Chief Examiner Date

SUMMARY

During the week of July 31, 2023, the NRC administered operator licensing examinations to seven Senior Reactor Operating-Instant (SRO-I) candidates. A request for withdrawal was submitted by the facility for one candidate on October 13, 2023, in accordance with the requirements in 10 CFR 55.31. Because the candidate withdrew after the exam began and before exam results were issued, the candidate is considered a failure in accordance with NUREG-1478. One SRO-I candidate failed both the written examination and operating examination, one SRO-I candidate failed the written examination and passed the operating examination, and two SRO-I candidates failed the operating examination and passed the written examination. The remaining two SRO-I 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 0/0 4/3 4/3 Operating Tests 0/0 3/4 3/4 Overall 0/0 2/5 2/5

3. Exit Meeting:

Amy Beasten, Reactor Engineer, NRC Michele DeSouza, Reactor Engineer, NRC Randy Strader, Chief, Reactor Operations Jacob Seiter, Training Program Manager Re-Exit Meeting on December 19, 2023 Amy Beasten, Reactor Engineer, NRC Michele DeSouza, Reactor Engineer, NRC Travis Tate, Branch Chief, NRC Nia Jones, Operator Licensing Assistant, NRC Randy Strader, Chief, Reactor Operations Jacob Seiter, Training Program Manager Thomas Newton, Deputy Director, Reactor Operations

J. Adams 2 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. The examiners discussed some apparent weaknesses among the expected level of knowledge for SRO candidates. Examiner observations include: general weakness of the expected level of knowledge concerning Area Radiation Monitor design, construction, and alarm/alert setpoints; design and construction of Gaseous Effluent Monitors; design and operation of reactor vessel level detection, temperature detection, and reactor and operator response to both.

Additionally, the examiners observed confusion surrounding requirements for nuclear instrumentation channels, including the number required and when those instruments are required to be operable, and which channels are required to be used to determine reactor power. Further, the examiners observed significant delays in identifying and diagnosing out-of-spec conditions during scenarios presented throughout the exam. The examiners also observed weaknesses among Emergency Plan implementation, specifically the ability to refer to the correct procedures and instructions to make an accurate and timely Emergency Action Level (EAL) declaration. At the conclusion of the meeting, the NRC examiner thanked the facility for their support in the administration of the examination.

NIST Center for Neutron Research Operator Licensing Examination Week of July 31, 2023 Enclosure 2

U. S. NUCLEAR REGULATORY COMMISSION NON-POWER REACTOR LICENSE EXAMINATION FACILITY: NIST Center for Neutron Research REACTOR TYPE: Test Reactor DATE ADMINISTERED: August 4, 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

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.

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 _____ (0.25 each)

A04 a b c d ___

A05 a b c d ___

A06 a b c d ___

A07 a b c d ___

A08 a b c d ___

A09 a b c d ___

A10 a b c d ___

A11 a b c d ___

A12 a b c d ___

A13 a b c d ___

A14 a b c d ___

A15 a b c d ___

A16 a b c d ___

A17 a b c d ___

A18 a b c d ___

A19 a b c d ___

(***** 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 _____ (0.25 each)

B02 a b c d ___

B03 a b c d ___

B04 a b c d ___

B05 a b c d ___

B06 a b c d ___

B07 a b c d ___

B08 a b c d ___

B09 a b c d ___

B10 a b c d ___

B11 a b c d ___

B12 a b c d ___

B13 a b c d ___

B14 a b c d ___

B15 a _____ b _____ c _____ d _____ (0.25 each)

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 _____ (0.25 each)

C07 a b c d ___

C08 a b c d ___

C09 a b c d ___

C10 a _____ b _____ c _____ d _____ (0.25 each)

C11 a b c d ___

C12 a b c d ___

C13 a b c d ___

C14 a _____ b _____ c _____ d _____ (0.25 each)

C15 a b c d ___

C16 a b c d ___

C17 a b c d ___

C18 a b c d ___

C19 a b c d ___

C20 a b c d ___

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

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

EQUATION SHEET

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

t P P0 e S S SCR

110 4 sec 1 K eff SUR 26 .06 eff CR1 1 CR2 2 CR1 1 K eff1 CR2 1 K eff 2 1 M 1

2 CR P P0 10 SUR (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 2

K eff1 K eff 2 K eff 1 DR DR0 e t 2 DR1 d1 DR2 d 2 2

K eff 6 Ci E n 2 2 1 2 DR R2 Peak2 Peak1 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, and Facility Operating Characteristics QUESTION A.01 [1.0 point]

Which ONE of the following is defined as the balance between production of neutrons and their absorption in the core for which core leakage can be neglected?

a. Infinite Multiplication Factor.

b. Effective Multiplication Factor.

c. Utilization Factor.

d. Reproduction Factor.

QUESTION A.02 [1.0 point]

A fast neutron will lose the most energy in a collision with which ONE of the following atoms?

a. U238

b. C12

c. H2

d. H1 QUESTION A.03 [1.0 point, 0.25 each]

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 1. Increases

b. Thermal non-leakage probability 2. Decreases

c. Fast non-leakage probability

d. Resonance escape probability

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

A subcritical reactor, keff is increased from 0.876 to 0.914. Which ONE of the following is the amount of reactivity that was added to the core?

a. 3.64% k/k

b. 4.75% k/k

c. 5.21% k/k

d. 6.74% k/k QUESTION A.05 [1.0 point, 0.25 each]

Replace X with the type of decay necessary (Alpha, Beta, Gamma or Neutron emission) to produce the following reactions. Choices may be used once, more than once, or not at all.

a. 92U238 90Th234 + X

b. 83Bi203 82Pb203 + X

c. 2He4 + 4Be9 6C12 + X

d. 84Po210 82Pb206 + X QUESTION A.06 [1.0 point]

The primary purpose of the ____________ material is thermalizing neutrons.

a. Moderator

b. Reflector

c. Absorber

d. Deflector QUESTION A.07 [1.0 point]

Which ONE of the following is an example of a FISSILE material?

a. Thorium-232

b. Uranium-233

c. Uranium-238

d. Plutonium-240

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.08 [1.0 point]

Given the thermal neutron flux (Ø) is 1.0 x 1013 neutrons/cm2/second, and the macroscopic cross-section (f) for fission is 0.1 cm-1. The fission rate is:

a. 1.0 x 1012 fissions/cm/second

b. 1.0 x 1014 fissions /cm/second

c. 1.0 x 1012 fissions/cm3/second

d. 1.0 x 1014 fissions/cm3/second QUESTION A.09 [1.0 point]

Given a reactor period of 17 seconds, how long will it take for reactor power to quadruple?

a. 15.23

b. 19.06

c. 23.57

d. 30.44 QUESTION A.10 [1.0 point]

Delayed neutrons contribute more to reactor stability than prompt neutrons because they are born at a ____________ kinetic energy and ____________ the average neutron generation time.

a. lower; decrease

b. higher; decrease

c. higher; increase

d. lower; increase

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.11 [1.0 point]

All of the following factors in the six-factor formula are affected by the enrichment of U-235 in the fuel EXCEPT:

a. Fast Fission Factor

b. Thermal Utilization Factor

c. Reproduction Factor

d. Resonance Escape Probability QUESTION A.12 [1.0 point]

Following a reactor scram from 15.6 MW on a light water reactor, the reactor period has stabilized and power level is decreasing at a constant rate. What is the reactor power six minutes following the scram?

a. 1.26 MW

b. 247 kW

c. 398 kW

d. 173 kW QUESTION A.13 [1.0 point]

Which ONE of the following best describes the importance of a negative temperature coefficient of reactivity?

a. An increase in reactor power causes an increase in fuel burnup which results in a positive reactivity addition, causing the power increase to slow or stop.

b. An increase in reactor power causes an increase in fuel temperature which results in a positive reactivity addition, causing the power increase to slow or stop.

c. An increase in reactor power causes an increase in fuel temperature which results in a negative reactivity addition, causing the power increase to slow or stop.

d. An increase in reactor power causes an increase in fuel burnup which results in a negative reactivity addition, causing the power increase to slow or stop.

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics 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]

As new fuel is being loaded into the core, the reactor operator is using a 1/M plot to monitor core loading. Which ONE of the following conditions could result in the reactor reaching criticality mass at a value greater than the predicted critical mass?

a. The detector and source are too close to each other.

b. The detector is located so that core load starts at a point close to the detector and subsequent loadings move farther from the detector.

c. The detector is located so that core load starts away from the detector and subsequent loading proceeds towards the detector.

d. Too much time elapses between subsequent core loadings.

QUESTION A.16 [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 smaller increase in neutron flux resulting in a shorter time to stabilize.

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

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.17 [1.0 point]

A subcritical reactor has a keff of 0.741. How much reactivity is added to change the keff to 0.966?

a. 0.117 k/k

b. 0.242 k/k

c. 0.314 k/k

d. 0.543 k/k QUESTION A.18 [1.0 point]

Which ONE of the following describes Integral Rod Worth?

a. The remaining 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.19 [1.0 point]

A reactor contains a neutron source of 1550 neutrons/second. If the stable total neutron production rate is 5100 neutrons/second, what is the value of keff?

a. 0.696

b. 0.751

c. 0.805

d. 0.958

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.20 [1.0 point]

The moderator temperature coefficient for a reactor is -0.00071 k/k/oF. What is the total reactivity change caused by a temperature decrease of 75oF?

a. 0.00218

b. 0.00376

c. 0.04211

d. 0.05325

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

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

Match the conditions or events in Column A to the appropriate level of classification in Column B. Options in Column B may be used once, more than once, or not at all.

Column A Column B

a. Fuel cladding failure with confinement 1. Notification of Unusual Event breach leading to a radiological effluent dose in excess of 375 mrem/24 hours at 2. Alert the site boundary.

3. Site Area Emergency

b. A fire affecting reactor safety systems requiring offsite support to extinguish.

c. Security breach affecting reactor confinement.

d. Fuel cladding failure with Helium Sweep Activity in excess of 50,000 cpm leading to a measured radiation level at the site boundary of > 20 mrem/hr for 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months .

QUESTION B.02 [1.0 point]

During reactor startup, as reactor power approaches 50kW, it becomes apparent that the estimated critical rod position is higher than expected by two degrees. Which ONE of the following actions is to be taken, in accordance with OI 1.1.1?

a. Because the estimated critical rod position differs from the actual critical position in a conservative direction, reactor operation may continue with approval from the Senior Reactor Operator on duty.

b. The reactor must be returned to a subcritical condition and the Senior Reactor Operator on Duty must be notified for approval to continue startup.

c. The reactor must be returned to a subcritical condition and the Chief of Reactor Operations must be notified for approval to continue startup.

d. The reactor must be manually scrammed as soon as the difference is identified.

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.03 [1.0 point]

In accordance with AP 0.3, Regulating Rod Failure, which ONE of the following is NOT an immediate action if the regulating rod malfunctions?

a. If manual control is normal, continue operation in manual mode maintaining power within +/-

0.7 MW of desired reactor power, not to exceed 20.7 MW.

b. Scram the reactor.

c. Confirm the regulating rod is in manual.

d. Insert and withdraw the regulating rod manually to determine full manual control is available.

QUESTION B.04 [1.0 point]

All of the following actions occur automatically on receipt of a loss of commercial power EXCEPT:

a. Both emergency diesel generators start to supply critical power.

b. Reactor scrams on low main D2O flow.

c. An uninterruptible power supply will continue to supply critical power.

d. The DC D2O shutdown pump selected to AUTO will start.

QUESTION B.05 [1.0 point]

In accordance with 10 CFR 20, which ONE of the following correctly defines the total effective dose equivalent (TEDE)?

a. The sum of the products of the weighting factors applicable to each of the body organs or tissues that are irradiated and the committed dose equivalent to these organs or tissues.

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

c. The concentration of a given radionuclide in air which, if breathed by the reference man for a working year of 2,000 hours0 days 0 hours 0 weeks 0 months under conditions of light work, results in an intake of one ALI.

d. The sum of the products of the dose equivalent to the organ or tissue and the weighting factors applicable to each of the body organs or tissues that are irradiated.

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.06 [1.0 point]

What is the purpose of RM3-2?

a. RM3-2 monitors the secondary coolant for the presence of N-16.

b. RM3-2 measures the radiation levels in the exhaust duct filters for the confinement building.

c. RM3-2 monitors room C-001 for high radiation levels in the vicinity of the rabbit receivers

d. RM3-2 checks for the presence of fission products in the Helium Gas Sweep System.

QUESTION B.07 [1.0 point]

Which ONE of the following modifications would NOT require a 50.59 evaluation?

a. Changing the frequency of the emergency core cooling system control valve exercises to semi-annually.

b. Doubling the amount of sample material in a previously approved beam tube experiment.

c. Deleting procedure OI 6.1.7, Rotational Latch Check.

d. Changing the shutdown margin parameter from $1.00 to $0.95.

QUESTION B.08 [1.0 point]

A sample reads 125 mrem/hr at a distance of 2 meters from the source. How far away from the source will the reading be 50 mrem/hr?

a. 1.5 m

b. 2.1 m

c. 3.2 m

d. 5.7 m QUESTION B.09 [1.0 point]

An experiment reading 60 mrem/hr was removed from the reactor. Four hours later, it reads 4 mrem/h. What is the half-life of the experiment?

a. 0.98 hr

b. 1.02 hr

c. 1.5 hr

d. 2.1 hr

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.10 [1.0 point]

You are currently a licensed operator at the NBSR. Which ONE of the following is a requirement of 10 CFR 55, Operators Licenses?

a. All licensed operators must pass an annual written requalification exam.

b. All licensed operators must successfully complete a continuous requalification program, not to exceed 24 months.

c. All licensed operators must actively perform the functions of an operator or senior operator for a minimum of 40 hours4.62963e-4 days 0.0111 hours 6.613757e-5 weeks 1.522e-5 months per quarter to maintain active status.

d. All licensed operators must have a medical examination by a physician every 3 years.

QUESTION B.11 [1.0 point]

In accordance with the NBSR Emergency Plan, which ONE of the following statements regarding NRC notification of an event is correct?

a. A Notification of Unusual Event must be reported to the NRC within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months of declaration.

b. An Alert due to a security breach affecting confinement must be reported to the NRC within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months of discovery.

c. A Site Area Emergency must be reported to the NRC within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

d. All emergency event notifications must be reported to the NRC within one hour of declaration.

QUESTION B.12 [1.0 point]

In accordance with OI 6.1.5, which ONE of the following fulfills the personnel requirements for insertion of fresh fuel into the core?

a. A Reactor Operator at the reactor top, a Senior Reactor Operator manning the console, and two additional workers, at least one of whom must be a qualified fuel handler per AR 4.0.

b. A Senior Reactor Operator at the reactor top, a Senior Reactor Operator manning the console, and two additional workers, at least one of whom must be a qualified fuel handler per AR 4.0.

c. A Reactor Supervisor at the reactor top, a Reactor Operator manning the console, and two additional workers, at least one of whom must be a qualified fuel handler per AR 4.0.

d. A Senior Reactor Operator at the reactor top, a Reactor Supervisor manning the console, and two additional workers, at least one of whom must be a qualified fuel handler per AR 4.0.

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.13 [1.0 point]

All of the following are Technical Specification requirements for operation EXCEPT:

a. Reactor outlet temperature shall not exceed 137°F.

b. The concentration of D2 in the Helium Sweep System shall not exceed 4% by volume.

c. The absolute reactivity of any experiment shall not exceed 0.5% .

d. The scram time shall not exceed 240 msec for a shim arm insertion of 5 degrees.

QUESTION B.14 [1.0 point]

In accordance with AP 0.1, D2O System Rupture, which ONE of the following actions should be taken when vessel level reaches 27?

a. Start top feed by opening DWV-32 and DWV-33

b. Pump D2O from Sump #4 to the Emergency Cooling Tank, preferably using DWV-21 and the purification system

c. Secure all secondary cooling systems and auxiliary D2O systems except components used for core cooling.

d. Open DWV-34 and DWV-35 (Plena feed)

QUESTION B.15 [1.0 point]

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. Excess reactivity verification 1. Monthly

b. Shim arm scram time verification 2. Quarterly

c. Fission product monitor channel test 3. Semi-Annually

d. Diesel generator test for automatic start 4. Annually and operation

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.16 [1.0 point]

During a routine Health Physics survey of room C-001, a dose rate of 150 mrem/hr at a distance of 2 feet from the rabbit receivers is detected. How should this area be posted?

a. No posting is required

b. Contaminated Area

c. Radiation Area

d. High Radiation Area QUESTION B.17 [1.0 point]

In accordance with OI 1.1.5, Reactor Normal Operations, the RRDS will change to Manual mode from Auto under all of the following conditions EXCEPT:

a. The regulating rod upper or lower limit is reached.

b. A reactor rundown occurs.

c. Reactor power drifts outside of 5% of the programmed setpoint.

d. The regulating rod switch is moved.

QUESTION B.18 [1.0 point]

Which ONE of the following individuals may assume the role of Emergency Coordinator, in accordance with the NBSR Emergency Plan?

a. Chief, Reactor Operations

b. Duty Reactor Supervisor

c. NBSR Senior Health Physicist

d. Director, NIST Center for Neutron Research

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.19 [1.0 point]

Which ONE of following is a possible cause of high Area Monitor Radiation, in accordance with AP 2.14?

a. Thermal column or beam port operation.

b. High radiation level at any of RM1-11 through RM1-13.

c. High radiation levels in ventilation associated with EF-3, EF-4, or EF-23.

d. High radiation due to a returned rabbit in the C-001 hood.

QUESTION B.20 [1.0 point]

Which ONE of the following accurately completes the following Technical Specification statement, to include its Basis?

The sum of the absolute values of reactivity of all experiments in the reactor and experimental facilities shall not exceed ________.

a. 2.6% , including 0.5% for the pneumatic irradiation system, 1.1% for experiments that can be removed during reactor operation, and 1.1% for semi-permanent experiments that can only be removed during reactor shutdown.

b. 2.6% , including 0.2% for the pneumatic irradiation system, 1.3% for semi-permanent experiments that can only be removed during reactor shutdown, and 1.1% for experiments that can be removed during reactor operation

c. 2.6% , including 0.2% for the pneumatic irradiation system, 1.3% for experiments that can be removed during reactor operation, and 1.1% for semi-permanent experiments that can only be removed during reactor shutdown.

d. 2.6% , including 0.2% for for semi-permanent experiments that can only be removed during reactor shutdown, 1.3% for experiments that can be removed during reactor operation, and 1.1% the pneumatic irradiation system.

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

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

All of the following statements about nuclear instrument channels NC-1 and NC-2 are true EXCEPT:

a. NC-1 and NC-2 produce a Startup Prohibit signal when count rate drops below 2 cps.

b. NC-1 and NC-2 produce a Withdraw Prohibit signal when the period decreases below 15 seconds.

c. NC-1 and NC-2 are normally installed required channels and used as startup channels when neutron levels fall below the detection capabilities of NC-3, -4, -5, -6, and -7.

d. NC-1 and NC-2 are B10 lined proportional counters.

QUESTION C.02 [1.0 point]

In accordance with NBSR Technical Specifications, when is confinement integrity NOT required?

a. When irradiated fuel is contained within the reactor vessel.

b. When the reactor is operating.

c. When there is movement of irradiated fuel outside a sealed container.

d. When shim arm repairs are being performed.

QUESTION C.03 [1.0 point]

Which ONE of the following best describes an NBSR fuel plate?

a. U3O8 plus aluminum powder dispersion fuel, enriched to approximately 93% 238U.

b. U3O8 plus aluminum powder dispersion fuel, enriched to approximately 93% 235U.

c. U2O6 plus aluminum powder dispersion fuel, enriched to approximately 93% 238U.

d. U2O6 plus aluminum powder dispersion fuel, enriched to approximately 93% 235U.

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

What happens when water level in the reactor vessel falls below the top of the Inner Reserve Tank (IRT)?

a. The IRT will start draining automatically through two nozzles near the bottom into the emergency cooling distribution pan and will completely drain in 28 minutes.

b. The IRT will start draining through manual manipulation of control valves DWV-34 and DWV-35 into the emergency cooling distribution pan and will completely drain in 28 minutes.

c. The IRT will start draining through manual manipulation of control valves DWV-34 and DWV-35 to each reactor inlet plenum and will completely drain in 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months .

d. The IRT will start draining automatically through two nozzles near the bottom into the emergency cooling distribution pan and the Emergency Cooling Tank will automatically replenish the IRT to prevent the IRT from completely draining.

QUESTION C.05 [1.0 point]

What happens to the control rods when a scram signal is received?

a. All five control rods drive into the core at normal speed until the rods reach their lower limit of travel.

b. The scram relays are energized, decoupling the magnetic clutches from each shim arm drive motor, allowing the four shim arms to fall into the core assisted by a large downward force produced by a spring on the shim drive shaft. The same signal causes the regulating rod to drive down into the core at normal speed until the rod reaches its lower limit of travel.

c. The scram relays are de-energized, decoupling the magnetic clutches from each shim arm drive motor, allowing the four shim arms to fall into the core assisted by a large downward force produced by a spring on the shim drive shaft. The same signal causes the regulating rod to drive down into the core at normal speed until the rod reaches its lower limit of travel.

d. The scram relays are de-energized, decoupling the magnetic clutches from the regulating rod arm drive motor, allowing it to fall into the core assisted by a large downward force produced by a spring on the rod drive shaft. The same signal causes the shim arms to drive down into the core at normal speed until the arms reach their lower limit of travel.

Category C: Facility and Radiation Monitoring Systems QUESTION C.06 [1.0 point, 0.25 point each]

Identify the operating condition in Column A with the type of requirement in Column B. Options in Column B may be used once, more than once, or not at all.

Column A Column B

a. Reactor outlet temperature < 147°F 1. Limiting Condition of Operation

b. Reactor vessel coolant level 25 inches 2. Limiting Safety System Setting below the overflow standpipe

3. Safety Limit

c. Reactor fuel cladding temperature 450°C

d. Reactor power 130%

QUESTION C.07 [1.0 point]

At a reactor power of 20 MW, approximately ________ of water flows through the inner plenum, and ________ of water flows through the outer plenum.

a. 2,300 gpm; 8,700 gpm

b. 2,300 gpm; 6,700 gpm

c. 6,700 gpm; 2,300 gpm

d. 8,700 gpm; 25,300 gpm QUESTION C.08 [1.0 point]

The safety relief valve is located on the ________ and functions to _________________.

a. reactor outlet piping; prevent overpressurization of the primary system

b. reactor inlet piping; prevent overpressurization of the primary system

c. reactor outlet piping; periodically offgas to the Helium sweep system for fission product monitoring

d. reactor inlet piping; periodically offgas to the Helium sweep system for fission product monitoring

Category C: Facility and Radiation Monitoring Systems QUESTION C.09 [1.0 point]

The ventilation system allows the Confinement Building atmosphere to be maintained

________, which ensures _________.

a. over-pressure during emergency operation; leakage is out of the Confinement Building

b. under-pressure during normal operation; leakage is out of the Confinement Building

c. over-pressure during all operation; leakage is into the Confinement Building

d. under-pressure during all operation; leakage is into the Confinement Building QUESTION C.10 [1.0 point, 0.25 each]

Match the exhaust system in Column A to the fan in Column B. Options in Column B may be used once, more than once, or not at all.

Column A Column B

a. Irradiated Air Exhaust 1. EF-2

b. Process Room Exhaust 2. EF-3

c. Stack Exhaust 3. EF-4

d. Normal Air Exhaust 4. EF-27 QUESTION C.11 [1.0 point]

All of the following equipment would remain energized in the event of a total loss of off-site power and emergency generator AC power, EXCEPT:

a. Effluent monitors

b. Reactor shim arm control

c. EF-3 and EF-27 DC powered fans

d. Nuclear instrumentation

Category C: Facility and Radiation Monitoring Systems QUESTION C.12 [1.0 point]

Which ONE of the following statements about the Log/Linear channels is true?

a. The log circuit produces indication of nuclear power between 10-10 and 10-3 amps.

b. The log circuit provides protection from a startup accident during low power conditions (less than 3% of full power).

c. The log circuit provides power indication between 0 and 150% of full power.

d. The log circuit provides protection from excessive power levels.

QUESTION C.13 [1.0 point]

Which ONE of the following statements about primary coolant temperature monitoring is NOT true?

a. The RTD on the primary coolant outlet piping has outputs that supply a signal for a reactor rundown.

b. The RTD on the primary coolant inlet piping has outputs that supply a signal for a reactor rundown.

c. The thermocouples have outputs that supply a signal for a reactor scram.

d. The Reactor Inlet Temperature Recorder Controller Channel, TRCA-3, regulates secondary coolant bypass flow around the cooling tower to maintain primary coolant temperature.

QUESTION C.14 [1.0 point]

Match the vessel levels in Column A to the appropriate action in Column B. Options in Column B may be used once, more than once, or not at all.

Column A Column B

a. 164 1. Alarm

b. 140 2. Rundown

c. 150 3. Scram

d. 145 4. No action

Category C: Facility and Radiation Monitoring Systems QUESTION C.15 [1.0 point]

All of the following statements concerning the duct filter radiation monitor channels are true EXCEPT:

a. RM1-11, RM1-12, and RM1-13 measure the radiation levels in the exhaust duct filters on the suction sides of the Irradiated Air Exhaust Fan, the Normal Air Exhaust Fan, and the Reactor Basement Recirculation Fan.

b. RD3-5 continuously samples effluent from EF-5 and EF-6 under emergency conditions.

c. RD3-4 continuously samples effluent from EF-4 and EF-23 under normal conditions.

d. RM1-11, RM1-12, and RM1-13 will cause a major scram and initiate confinement if activity in excess of 50,000 cpm is detected.

QUESTION C.16 [1.0 point]

Which ONE of the following isotopes would indicate a primary to secondary leak inside the coolant system?

a. Na-24

b. Cs-137

c. Tritium

d. N-16 QUESTION C.17 [1.0 point]

In accordance with Technical Specifications, which ONE of the following statements regarding operability of the Radiation and Effluent Monitoring Systems is true?

a. Reactor operation is not permissible unless all facility radiation monitors are operable.

b. The fission product monitor is not required to be operable at reactor powers below 100kW.

c. When required monitors are inoperable, portable instruments may be substituted for any normally installed monitor for periods not to exceed one week, or the duration of a reactor run.

d. The normal and irradiation air gasesous effluent monitors may be inoperable for the duration of a reactor run as long as the stack air effluent monitor remains operable.

Category C: Facility and Radiation Monitoring Systems QUESTION C.18 [1.0 point]

Which ONE of the following best describes the reason for the high sensitivity of a Geiger-Mueller detector?

a. Coating with special nuclear material

b. A larger tube, so target area is bigger for all incident events

c. Lower voltage applied to the detector helps to amplify all incident events

d. Any incident radiation event causing primary ionization results in ionization of entire detector QUESTION C.19 [1.0 point]

Which ONE of the following best describes the shim arm drive assembly?

a. The shim arm drive assembly consists of an electromagnetically coupled motor, gear reduction system, and an acme screw type drive.

b. The shim arm drive assembly consists of a large compression spring with a ball nut and screw jack.

c. The shim arm drive assembly consists of an electromechanical drive, with a stepper motor, magnetic coupler, and rack-and-pinion gear system.

d. The shim arm drive assembly consists of two 2-phase electric servo motors in parallel driving a lead-screw nut combination.

Category C: Facility and Radiation Monitoring Systems QUESTION C.20 [1.0 point]

Which ONE of the following best describes the flow path for the primary coolant system through the reactor vessel?

a. Water flows into the two inlet plena, up through the reactor vessel. Heat generated by fission is removed by coolant flowing up the outer plenum and up and through the center six fuel elements. Coolant from the inner plenum flows up and through the remaining fuel elements.

b. Water flows into the two inlet plena, down through the reactor vessel. Heat generated by fission is removed by coolant flowing down the outer plenum and down and through the center six fuel elements. Coolant from the inner plenum flows down and through the remaining fuel elements.

c. Water flows into the two inlet plena, up through the reactor vessel. Heat generated by fission is removed by coolant flowing up the inner plenum and up and through the center six fuel elements. Coolant from the outer plenum flows up and through the remaining fuel elements.

d. Water flows into the two inlet plena, down through the reactor vessel. Heat generated by fission is removed by coolant flowing down the inner plenum and down and through the center six fuel elements. Coolant from the outer plenum flows down and through the remaining fuel elements.

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

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

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics A.01 Answer: a.

Reference:

DOE Fundamentals Handbook, Volume 2, Module 3, p. 2 A.02 Answer: d.

Reference:

NRC standard question A.03 Answer: (1) Increases; b. (2) Decreases; c. (2) Decreases; d. (2) Decreases

Reference:

Burn, Introduction to Nuclear Reactor Operations, Section 3.3.2, page 3-18.

A.04 Answer: b.

Reference:

Burn, Introduction to Nuclear Reactor Operations, Section 3.3.4, page 3-20&21

=(keff2-keff1)/(keff1*keff2)

(0.914-0.876)/(0.914*0.876) 0.0475 k/k = 4.75 % k/k A.05 Answer: a. alpha b. +1 0 c. neutron d. alpha

Reference:

NRC Standard Question A.06 Answer: a.

Reference:

DOE Fundamentals Handbook, Nuclear Physics and Reactor Theory, Volume 1, Module 2, page 23 A.07 Answer: b

Reference:

NRC Glossary, Fertile material, Fissionable material, Fissile material A.08 Answer: c.

Reference:

Fission rate = thermal flux (Ø) x macroscopic cross-section.

Reference:

P = P0 et/T 4 = 1t/17s ln(4) = ln(t/17s) 1.386 = t/17s t = (1.386)*17s t = 23.57 seconds

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

Reference:

Burn, Introduction to Nuclear Reactor Operations, Section 3.3.2, page 3-18.

A.11 Answer: a.

Reference:

DOE Fundamentals Handbook, Volume 2, Module 3, p. 3-16 A.12 Answer: d.

Reference:

P = P0 e-t/T P = 15.6 MW

e(360s/-80s) 15.6 MW

e-4.5 15.6 MW

0.01110899; P = 0.1733 MW = 173 kW A.13 Answer: c.

Reference:

DOE Fundamentals Handbook, Volume 2, Module 3, p. 28 A.14 Answer: c

Reference:

DOE Fundamentals Handbook, Nuclear Physics and Reactor Theory, Volume 1, Module 1, page 30 A.15 Answer: c.

Reference:

Burn, Section 5.5, p. 5-18 A.16 Answer: d.

Reference:

Burn, R., Introduction to Nuclear Reactor Operation, Section 5.3, p. 5-12 A.17 Answer: c.

Reference:

Burn, Section 3.3.4, p 3-20-21

= (keff2-keff1)/(keff1*keff2)

= (0.966-0.741) / (0.741*0.966)

= 0.314 k/k A.18 Answer: d

Reference:

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

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

Reference:

Source CR = (S) / (1 - keff)

(1550) / (1 - keff) = 5100 keff = 0.696 DOE Fundamentals Handbook Nuclear Physics and Reactor Theory, Volume 2, Module 4, page 4 A.20 Answer: d.

Reference:

DOE Handbook Nuclear Physics & Reactor Theory, Volume 2, Section Reactivity, Subsection Reactivity Coefficients and Reactivity Defect, page 21,

= T*T = (-0.00071 k/k /oF) * (-75oF) = 0.05325k/k

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

Category B: Normal/Emergency Operating Procedures and Radiological Controls B.01 Answer: a. (3) Site Area Emergency; b. (1) Notification of Unusual Event; c. (2) Alert;

d. (2) Alert

Reference:

NBSR Emergency Plan and Emergency Instruction 0.3 B.02 Answer: c.

Reference:

OI 1.1.1, Reactor Startup Up to 20 MW B.03 Answer: b.

Reference:

AP 0.3, Regulating Rod Failure B.04 Answer: a.

Reference:

AP 0.2, Commercial Power Failure B.05 Answer: b.

Reference:

10 CFR 20.1003 B.06 Answer: d.

Reference:

NCNR SAR 7.3.2.4 B.07 Answer: b.

Reference:

10 CFR 50.59 B.08 Answer: c.

Reference:

DR1*(D1)2 = DR2*(D2)2 ;

125 mrem*(2)2 = 50 mrem(d)2 d = 3.2 m B.09 Answer: b.

Reference:

DR=DR0e(-t) T1/2=0.693/

DR = DR0 e-.693/T1/2 4 = 60 e-(.693)(4)/T1/2 0.0667 = e-(2.772)/T1/2 ln(0.0667) = ln(e-(2.772)/T1/2)

-2.708 = -2.772 / T1/2 T1/2 = -2.772 / -2.708 T1/2 = 1.02 hr B.10 Answer: b.

Reference:

10 CFR Part 55

Category B: Normal/Emergency Operating Procedures and Radiological Controls B.11 Answer: b.

Reference:

NBSR Emergency Plan, p. 11 B.12 Answer: c.

Reference:

NBSR OI 6.1.5 B.13 Answer: a.

Reference:

NBSR TS 2.2, 3.2.1, 3.3.1, 3.8.1 B.14 Answer: d.

Reference:

AP 0.1, D2O System Rupture B.15 Answer: a. (4) Annually; b. (3) Semi-annually; c. (1) Monthly; d. (2) Quarterly

Reference:

NBSR TS 4.1.2, 4.2.1, 4.7.1 B.16 Answer: d.

Reference:

10 CFR 20 B.17 Answer: c.

Reference:

OI 1.1.5, Reactor Normal Operations B.18 Answer: a.

Reference:

NBSR Emergency Plan, Section 3.1 B.19 Answer: a.

Reference:

AP 2.14, Area Monitor Radiation High B.20 Answer: c.

Reference:

NBSR TS 3.8.1 and Basis

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

Category C: Facility and Radiation Monitoring Systems C.01 Answer: c.

Reference:

NBSR SAR 7.3.1.1 C.02 Answer: a.

Reference:

NBSR TS 3.4.1 C.03 Answer: b.

Reference:

NBSR SAR 4.2.1 C.04 Answer: a.

Reference:

NBSR SAR 6.1.1 C.05 Answer: c.

Reference:

NBSR SAR 7.2.2.2 C.06 Answer: a. (2) LSSS; b. (1) LCO; c. (3) SL; d. (2) LSSS

Reference:

NBSR Technical Specifications 2.1, 2.2, 3.3.1 C.07 Answer: b.

Reference:

NBSR SAR 5.2.2 C.08 Answer: a.

Reference:

NBSR SAR 5.2.2.4.2 C.09 Answer: d.

Reference:

NBSR SAR 6.1.2 C.10 Answer: a. (3) EF-4; b. (4) EF-27; c. (1) EF-2; d. (2) EF-3

Reference:

NBSR SAR 6.2.3.1.2 C.11 Answer: c.

Reference:

NBSR SAR 8.2.2 C.12 Answer: a.

Reference:

NBSR SAR 7.3.1.1 C.13 Answer: b.

Reference:

NBSR SAR 5.2.2.5.2

Category C: Facility and Radiation Monitoring Systems C.14 Answer: a. (1) Alarm; b. (3) Scram; c. (2) Rundown; d. (1) Alarm

Reference:

AP 4.15, 4.21, 3.1, 3.2 C.15 Answer: d.

Reference:

NBSR SAR 7.3.2.2, AP 4.6, AP 4.7, AP 4.8 C.16 Answer: d.

Reference:

NBSR SAR 7.3.2.3 C.17 Answer: c.

Reference:

NBSR TS 3.7 C.18 Answer: d.

Reference:

NRC standard question C.19 Answer: b.

Reference:

NBSR SAR 4.2.2.1 C.20 Answer: c.

Reference:

NBSR SAR 5.2.2

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

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

ML23257A198

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