Text

Examination Report Letter No. 50-020/OL-24-02 Massachusetts Institute of Technology
	ML24220A150
Person / Time
Site:	MIT Nuclear Research Reactor
Issue date:	10/09/2024
From:	Travis Tate; NRC/NRR/DANU/UNPO
To:	Foster J; Massachusetts Institute of Technology (MIT)
References
	50-020/OL-24-02 OL-24-02
	Download: ML24220A150 (1)
	v • d • e

John P. Foster Director of Reactor Operations Nuclear Reactor Laboratory Massachusetts Institute of Technology 138 Albany Street, MS NW12-110 Cambridge, MA 02139

SUBJECT:

EXAMINATION REPORT NO. 50-020/OL-24-02, MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Dear John Foster:

During the week of September 23, 2024, the U.S. Nuclear Regulatory Commission (NRC) administered an operator licensing examination at your Massachusetts Institute of Technology Nuclear Reactor Laboratory. The examination was 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 Michele DeSouza at 301-415-0747 or via email at Michele.DeSouza@nrc.gov.

Sincerely, 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.50-020

Enclosures:

1. Examination Report No. 50-020/OL-24-02

2. Written examination cc: w/enclosures to GovDelivery Subscribers October 9, 2024 Signed by Tate, Travis on 10/09/24

ML24220A150 NRR-079 OFFICE NRR/DANU/UNPO/CE NRR/DANU/UNPO/OLA NRR/DANU/UNPO/BC NAME ABeasten NJones TTate DATE 10/9/2024 10/9/2024 10/9/2024 U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.:

50-020/OL-24-02 FACILITY DOCKET NO.:

50-020 FACILITY LICENSE NO.:

R-37 FACILITY:

Massachusetts Institute of Technology EXAMINATION DATES:

Week of September 23, 2024 SUBMITTED BY:

SUMMARY

During the week of September 23, 2024, the NRC administered operator licensing examinations to three Reactor Operator (RO) candidates, one RO retake, one Senior Reactor Operator-Instant (SROI) and one SROI retake. One RO, one RO-retake, and two SROI passed all applicable portions of the licensing examinations. Two RO passed the written examinations but failed the operating tests.

REPORT DETAILS 1.

Examiner:

Michele C. DeSouza, Chief Examiner, NRC 2.

Results:

RO PASS/FAIL SRO PASS/FAIL TOTAL PASS/FAIL Written 4/0 2/0 6/0 Operating Tests 2/2 1/0 3/2 Overall 2/2 2/0 4/2 3.

Exit Meeting:

Michele C. DeSouza, Chief Examiner, NRC Amy E. Beasten, PhD, Chief Examiner, NRC Frank Warmsley, Interim Superintendent, MIT Edward Lau, Assistant Director, MIT Prior to administration of the written examination, based on facility comments, adjustments were accepted. Comments provided corrections and additional clarity to questions/answers and identified where changes were appropriate based on current facility conditions.

Upon completion of all operator licensing examinations, the NRC examiner met with facility staff representatives to discuss the results. At the conclusion of the meeting, the NRC examiner thanked the facility for their support in the administration of the examination.

Michele C. DeSouza 10/1/2024 Michele C. DeSouza, Chief Examiner Date

Enclosure 2 Massachusetts Institute of Technology Operator Licensing Examination Week of September 23, 2024

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

Massachusetts Institute of Technology REACTOR TYPE:

Tank DATE ADMINISTERED:

09/23/2024 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 and a 70% overall is required to pass the examination. Examinations will be picked up three (3) hours after the examination starts.

CATEGORY VALUE

% OF TOTAL CANDIDATE'S SCORE

% OF CATEGORY VALUE CATEGORY 20.00 33.0 A. REACTOR THEORY, THERMODYNAMICS, AND FACILITY OPERATING CHARACTERISTICS 20.00 33.0 B. NORMAL AND EMERGENCY OPERATING PROCEDURES AND RADIOLOGICAL CONTROLS 20.00 33.0 C. FACILITY AND RADIATION MONITORING SYSTEMS 60.00 TOTALS FINAL GRADE All work done on this examination is my own. I have neither given nor received aid.

Candidate's Signature

Category A - Reactor Theory, Thermodynamics, & Facility Operating Characteristics A N S W E R S H E E T 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 ________

(0.25 each)

A14 a b c d ___

A15 a ________ b ________ c ________ d ________ (0.25 each)

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 ________

(0.25 each)

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

Category B - Normal/Emergency Operating Procedures and Radiological Controls A N S W E R S H E E T Multiple Choice (Circle or X your choice)

If you change your Answer, write your selection in the blank.

B01 a b c d ___

B02 a b c d ___

B03 a b c d ___

B04 a b c d ___

B05 a b c d ___

B06 a b c d ___

B07 a b c d ___

B08 a b c d ___

B09 a ________ b ________ c ________ d ________

(0.25 each)

B10 a b c d ___

B11 a b c d ___

B12 a b c d ___

B13 a b c d ___

B14 a b c d ___

B15 a b c d ___

B16 a b c d ___

B17 a b c d ___

B18 a b c d ___

B19 a b c d ___

B20 a b c d ___

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

Category C - Facility and Radiation Monitoring Systems A N S W E R S H E E T Multiple Choice (Circle or X your choice)

If you change your Answer, write your selection in the blank.

C01 a b c d ___

C02 a b c d ___

C03 a b c d ___

C04 a b c d ___

C05 a b c d ___

C06 a b c d ___

C07 a b c d ___

C08 a b c d ___

C09 a b c d ___

C10 a b c d ___

C11 a b c d ___

C12 a b c d ___

C13 a b c d ___

C14 a b c d ___

C15 a b c d ___

C16 a b c d ___

C17 a b c d ___

C18 a b c d ___

C19 a b c d ___

C20 a b c d ___

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

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

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

1.

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

2.

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

3.

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

4.

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

5.

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

6.

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

7.

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

8.

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

9.

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

10.

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

11.

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

12.

There is a time limit of three (3) hours for completion of the examination.

EQUATION SHEET

=

+

DR - Rem, Ci - curies, E - Mev, R - feet 1 Curie = 3.7 x 1010 dis/sec 1 kg = 2.21 lb 1 Horsepower = 2.54 x 103 BTU/hr 1 Mw = 3.41 x 106 BTU/hr 1 BTU = 778 ft-lb

°F = 9/5 °C + 32 1 gal (H2O) 8 lb

°C = 5/9 (°F - 32) cP = 1.0 BTU/hr/lb/°F cp = 1 cal/sec/gm/°C

2 2

max

P 1

sec 1.0

eff

te P

P 0

eff K

S S

SCR

1

sec 10 1

4

eff SUR 06 26

2 1

1 1

2 1

eff eff K

CR K

CR

2 2

1 1

CR CR 2

1 1

1 eff eff K

K M

1 2

1 1

CR CR K

M eff

)

(

0 10 t

SUR P

P

0 1

P P

eff eff K

K SDM

1

2 1

1 2

eff eff eff eff K

K K

K

693

.0 2

1 T

eff eff K

K 1

t e

DR DR

0

2 6

R n

E Ci DR 2

2 2

2 1

1 d

DR d

DR

1 2

2 2

Peak Peak

T UA H

m T

c m

Q P

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

[1.0 point]

Which ONE of the following parameters is the MOST significant in determining the differential rod worth of a control rod?

a.

Rod speed b.

Flux shape in the fuel core c.

Reactor power d.

Fuel temperature QUESTION A.02

[1.0 point]

Which ONE of the following is defined as the balance between absorption of thermal neutrons by the fuel and production of fast neutrons from thermal fission?

a.

Utilization factor b.

Reproduction factor c.

Infinite Multiplication factor d.

Effective Multiplication factor QUESTION A.03

[1.0 point]

When the reactor is exactly critical, which ONE of the following is the MINIMUM reactivity that must be added to produce PROMPT criticality?

a.

0.005 k/k.

b.

0.065 k/k.

c.

eff.

d.

2 eff.

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.04

[1.0 point]

Which ONE of the following is the expected stable neutron count rate, given a source strength of 390 neutrons per second (N/sec) and a multiplication factor of 0.3?

a.

130 neutrons/second b.

414 neutrons/second c.

557 neutrons/second d.

715 neutrons/second QUESTION A.05

[1.0 point]

Which ONE of the following is the definition of excess reactivity? The amount of reactivity ______.

a.

needed to achieve prompt criticality.

b.

associated with burnable poisons.

c.

available above that which is required to keep the reactor critical.

d.

available below that which is required to make the reactor subcritical.

QUESTION A.06

[1.0 point]

Which ONE of the following is the definition for Differential Control Rod Worth? The reactivity a.

Due to control rod position (K/K).

b.

Change per unit of rod motion (K/K/in).

c.

Due to the difference in rod speed (K/K/in/min).

d.

Still available for shutdown after control rod withdrawal.

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.07

[1.0 point]

In a subcritical reactor, k-eff is increased from 0.614 to 0.895. Which one of the following is the amount of reactivity that was added to the core?

a.

11.23 %k/k b.

24.43 %k/k c.

51.13 %k/k d.

77.92 %k/k QUESTION A.08

[1.0 point]

A reactor is shutdown with a shutdown margin of 2.0% k/k. If control rods are withdrawn until the count rate increases by a factor of 10, and the reactor is still subcritical, what is the new Keff?

a.

0.990.

b.

0.992.

c.

0.995.

d.

0.998.

QUESTION A.09

[1.0 point]

A radioactive material was removed from a reactor core, it reads 120.00 rem/h. Forty-eight hours later, it reads 4.00 rem/h. What is the materials half-life?

a.

9.78 hours9.027778e-4 days 0.0217 hours 1.289683e-4 weeks 2.9679e-5 months b.

22.14 hours1.62037e-4 days 0.00389 hours 2.314815e-5 weeks 5.327e-6 months c.

40.13 hours1.50463e-4 days 0.00361 hours 2.149471e-5 weeks 4.9465e-6 months d.

56.11 hours1.273148e-4 days 0.00306 hours 1.818783e-5 weeks 4.1855e-6 months

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

[1.0 point]

Which ONE of the following factors is MOST affected by an increase in fission product poisoning?

a.

fast fission factor b.

reproduction factor c.

thermal utilization factor d.

resonance escape probability factor QUESTION A.11

[1.0 point]

Two common FISSION PRODUCTS that have especially large neutron cross sections and play a significant role in reactor physics are Samarium-149 and _________.

a.

Nitrogen-16.

b.

Argon-41.

c.

Iodine-131.

d.

Xenon-135.

QUESTION A.12

[1.0 point]

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

a.

Depletion of Uranium fuel.

b.

Depletion of a burnable poison.

c.

Inserting an experiment adding positive reactivity.

d.

Lowering moderator temperature if the moderator temperature coefficient is negative.

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.13

[1.0 point, 0.25 each]

The listed isotopes are potential daughter products due to the radioactive decay of 35Br87.

Identify the type of decay to produce each of the isotopes: Alpha, Beta+, Beta-, Gamma or Neutron emission (Answers may be used once, more than once or not at all).

a. 33As83

b. 35Br86

c. 35Br87

d. 36Kr87 QUESTION A.14

[1.0 point]

A reactor with k-eff = 0.8 contributes 1000 neutrons in the first generation. Changing from first generation to third generation, what is the total number of neutrons produced in all three generations?

a.

1940 neutrons b.

2040 neutrons c.

2440 neutrons d.

3640 neutrons QUESTION A.15

[1.0 point, 0.25 each]

Identify each one of the following isotopes as either a FERTILE or FISSILE material. (Answers may be used once, more than once, or not at all) a.

Thorium-232 b.

Uranium-235 c.

Uranium-238 d.

Plutonium-239

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics QUESTION A.16

[1.0 point]

Which factors of the six-factor formula are affected by an INCREASE in core moderator temperature and how are they affected? Lf - Fast non-leakage probability Lt - Thermal non-leakage probability - Fast fission factor p - Resonance escape probability - Reproduction factor f - Thermal utilization factor a.

Lf, Lt, p, f b.

, Lf, Lt, p.

c.

, Lf, Lt, p,, f d.

, Lf, Lt, p,, f QUESTION A.17

[1.0 point]

What is a total reactivity change due to a temperature DECREASE of 150oF? Given the moderator temperature coefficient of -0.00081 k/k/F.

a.

0.1215 k/k.

b.

-0.1215 k/k.

c.

0.1275 k/k.

d.

-0.1275 k/k.

QUESTION A.18

[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.

From 1 Watt to 5 Watts b.

From 10 Watts to 30 Watts c.

From 10 kWatts to 20 kWatts d.

From 100 kWatts to 150 kWatts

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

[1.0 point]

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

a.

Macroscopic Cross Section.

b.

Thermal Cross Section.

c.

Mean Free Path.

d.

Decay Constant.

QUESTION A.20

[1.0 point]

Identify each one of the following as either an ABSORBER (A), POISON (P), or REFLECTOR (R). (Answers may be used once, more than once, or not at all) a.

Beryllium b.

Graphite c.

Boron-10 d.

Xenon-135

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

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.01

[1.0 point]

In accordance with MIT Administrative Procedure PM 1.3, which ONE of the following is NOT a duty for the Shift Supervisor?

a.

Verify the completeness and accuracy of the log book entries on the shift.

b.

Inform the Operations Superintendent of unusual occurrences on the shift.

c.

Present at the reactor room whenever the Console Relief/Turnover is conducted.

d. Authorize and witness both startups and increases in reactor power of greater than 10%.

QUESTION B.02

[1.0 point]

During the reactor operation, the containment building's ventilation system shuts down, and the stack gas monitor is reading at 650 kcpm. This event is classified to be _____.

a. Alert.

b. General Emergency.

c. Site Area Emergency.

d. Notification of Unusual Events.

QUESTION B.03

[1.0 point]

What is the reason a normal reactor startup requires reactor power to be maintained at 1MW for 5 minutes?

a.

Prevents buckling of the voltage potentiometers b.

Allows for cooling tower flow to be switched to spray c.

Excess reactivity must be measured prior to achieving full power d.

Thermal equilibrium between the core and coolant reduces stress on fuel cladding, core structures, and thermal shield

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.04

[1.0 point]

During the reactor shutdown, the Stack Gas Monitor is reading 140 kcpm, the event is classified to be which ONE of the following?

a.

Notification of Unusual Events b.

Alert c.

Site Area Emergency d.

General Emergency QUESTION B.05

[1.0 point]

Which ONE of the following conditions is NOT a possible symptom if the recombiner heaters malfunctioned?

a.

A rapidly decreasing D2O cover gas pressure.

b.

A reactor coolant outlet temperature of 51C.

c.

A high pressure D2O helium cover gas alarm.

d.

A high recombiner temperature being observed during the hourly readings.

QUESTION B.06

[1.0 point]

Which ONE of the following conditions requires the US Nuclear Regulatory Commission approval prior to implementation of the changes?

a.

Minor changes of PM Chapter 1, Administrative Procedures b.

Replace a primary coolant pump with an identical pump c.

Add responsibilities to the Radiation Protection Officer in the MITR operational procedures d.

Minor changes to reduce the MITR Reactor Safeguards Committee members from nine persons to five

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.07

[1.0 point]

Which ONE of the following occurrence reports shall be made by telephone or other communication systems to the US Nuclear Regulatory Commission Headquarters Operations Center within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ?

a.

Changes of experiment samples b.

Operation in violation of a safety limit c.

The total amount of solid waste packaged d.

Changes of PM Chapter 1 - Administrative Procedures QUESTION B.08

[1.0 point]

Which ONE of the following is the MINIMUM review and approval requirement prior to a change in core configuration?

a.

Two Senior Reactor Operator.

b.

Reactor Operator and Reactor Engineer.

c.

Reactor Operator and Senior Reactor Operator.

d.

Reactor Engineer and Senior Reactor Operator with minimum of 5 years of experience.

QUESTION B.09

[1.0 point, 0.25 each]

Identify the PRIMARY source (irradiation of AIR, irradiation of WATER, irradiation of reactor STRUCTURE or FISSION product) for EACH of the following radioisotopes.

a.

Argon-41 b.

Aluminum-28 c.

Nitrogen-16 d.

Iodine-135

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.10

[1.0 point]

Which ONE of the following is NOT an expected protective action of the console operator when the radiation alarms are on due to high radiation levels detected inside the containment building?

a.

Turn on the evacuation siren b.

Turn on the Emergency Power System c.

Energize the back-lighted signs at each personnel lock door to indicate whether or not use of that personnel lock is allowed.

d.

Use the intercom to describe the problem and direct experimenters to the desired personnel lock.

QUESTION B.11

[1.0 point]

During reactor operation, what IMMEDIATE ACTION is required when the core purge monitor exceeds 250 kcpm?

a.

Shutdown the reactor via All Rods In (ARI) b.

Reset the alarm and restart the core purge blower c.

Evaluate and determine the leakage from a fuel element or fueled in-core sample d.

Request that personnel from the Reactor Radiation Protection Office draw and analyze a sample from the core purge system QUESTION B.12

[1.0 point]

Which ONE of the following is the criteria for the Emergency Core Cooling System?

a.

Ensure at least 20 gpm within 10 minutes b.

Prevent overheating of the secondary coolant system c.

Close heat exchanger valves to ensure it does not overheat d.

Each element receives at least 20% of the average spray to all elements

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.13

[1.0 point]

Which ONE of the following federal regulations requires the MITR operator requalification program be conducted for a continuous period not to exceed 24 months?

a.

10 CFR 19 b.

10 CFR 20 c.

10 CFR 50

d. 10 CFR 55 QUESTION B.14

[1.0 point]

During the MITR-II reactor operation, the alarm of high-level emergency power channel is on due to the power above the normal operating level of 5.9 MW. The console operator must perform the following immediate actions, EXCEPT:

a.

Shut down the reactor.

b.

Acknowledge the alarm.

c.

Lower the reactor power level to the normal level of 5.9 +/- 0.05 MW or below.

d.

Check all other neutron level indications to see if the alarm was caused by an actual high-power level.

QUESTION B.15

[1.0 point]

All of the following requirements can support an explosive specimen irradiation, EXCEPT:

a.

Doubly encapsulation.

b.

Container pressure test.

c.

Use of unanalyzed amounts.

d.

Estimation of pressure buildup.

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.16

[1.0 point]

What emergency classification is an abnormal loss of coolant where core tank level cannot be maintained above scram setpoint but is above the anti-siphon valves?

a.

Alert b.

Notification of unusual event c.

Site Area Emergency d.

General Emergency QUESTION B.17

[1.0 point]

What is the dose rate at 1 foot given a 2 curie radioactive source results in emission of 150 keV gamma 60% of the time?

a.

90 mRem b.

180 mRem c.

1080 mRem d.

2160 mRem QUESTION B.18

[1.0 point]

Per MITR Technical Specifications, what is the MINIMUM shutdown margin with the most reactive shim blade and regulating rod fully withdrawn?

a.

1.0% k/k b.

3.0% k/k c.

0.1% k/k d.

0.3% k/k

Category B: Normal/Emergency Operating Procedures and Radiological Controls QUESTION B.19

[1.0 point]

In accordance with MITR Technical Specifications, which ONE of the following does NOT require an annual surveillance?

a.

Fuel in storage pool b.

Core tank level c.

Neutron flux level d.

Shield coolant flow QUESTION B.20

[1.0 point]

Calculate an individuals total whole body dose given the individual received the following doses: 15 mrad of alpha (alpha quality factor is 20), 20 mrad of gamma, and 20 mrad of neutron (unknown energy neutron quality factor is 10).

a.

55 mrem b.

308 mrem c.

435 mrem d.

520 mrem

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

Category C: Facility and Radiation Monitoring Systems QUESTION C.01

[1.0 point]

To minimize radiation streaming from a reactor core to top shield lid, which ONE of the following is correct? The shield and plug are __________.

a.

made of Pb and a beam port is blanketed by helium b.

made of Al and a gasket cover is bolted over the beam ports opening c.

stepped and gas seals are made by placing a ring against the Al flange d.

made of polyethylene and a gasket cover is bolted over the beams ports opening QUESTION C.02

[1.0 point]

Before increasing reactor power above 100 kW and at least every two hours during operation above 100 kW, the reactor operator verifies the temperature in the middle of the recombiner shall be ____.

a.

equal to 50°C.

b.

less than 15°C.

c.

greater than 50°C.

d.

between 30°C to 40°C.

QUESTION C.03

[1.0 point]

Which ONE of the following interlocks associated with the Rod Control System will cause the selected shim blade to be inserted if xenon were to be burned out as the result of a startup following a brief shutdown?

a.

Automatic Control b.

Startup Interlocks c.

Subcritical Interlock d.

Automatic Rundown

Category C: Facility and Radiation Monitoring Systems QUESTION C.04

[1.0 point]

In the event of a loss of building power, which ONE of the following does the emergency battery DIRECTLY provide 120-volt DC power to?

a.

Emergency lighting panel b.

Radiation area, continuous air, and stack gas monitor c.

Entire building can be powered by the emergency battery d.

No systems directly receive power from the emergency battery QUESTION C.05

[1.0 point]

Sampling of the secondary system occurs once every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months during normal operation to detect which ONE of the following isotopes?

a.

Tritium b.

Boron-10 c.

Argon-41 d.

Iodine-131 QUESTION C.06

[1.0 point]

Which one of the following conditions is NOT a reason for an alarm actuated by the make-up water systems annunciator?

a.

Low or high level in the storage tank.

b.

High conductivity in the makeup water cleanup loop.

c.

Reactor coolant outlet temperature is 50C.

d.

There is a leak, or low flow in the makeup water cleanup loop.

Category C: Facility and Radiation Monitoring Systems QUESTION C.07

[1.0 point]

During the reactor operation, the shim blades are raised. Which ONE of the following changes NORMALLY would NOT occur.

a.

The magnitude of the thermal neutron flux available at the beam port reentrant thimble tips decreases.

b.

The axial spatial location of the point of maximum flux will be higher.

c.

Power density decreases in the A and B-ring but rises in the C-ring.

d. The level of coolant in the primary core tank increases.

QUESTION C.08

[1.0 point]

During a reactor operation at 2 MW power, you discover abnormal radioactivity above the core, and the continuous purge of the air space is stopped. Which ACTION violates the TS requirements?

a.

Investigate the cause of the isolation and open the air space.

b.

Reduces the reactor power to 99 kW within five minutes.

c.

Resume the continuous purge as soon as possible.

d. Continue reactor operation at 2MW power.

QUESTION C.09

[1.0 point]

What is the normal operating temperature setpoint for High Temperature Reactor Outlet - MT-5A warning to warn that the reactor is receiving insufficient cooling?

a.

60 ºC b.

50 ºC c.

53 ºC

d. 40 ºC

Category C: Facility and Radiation Monitoring Systems QUESTION C.10

[1.0 point]

Which ONE of the following safety channels has a Reflector Dump action in addition to a reactor scram?

a.

Core tank level.

b.

Reflector tank level.

c.

D2O reflector flow rate.

d.

D2O dump valve selector switch.

QUESTION C.11

[1.0 point]

The reactor operator CANNOT initiate a major scram from which ONE of the following.

a. Control room console

b. Special remote panel

c. Utility room remote panel

d. Fission converter control console QUESTION C.12

[1.0 point]

What is the main reason that, beyond the subcritical position, operating procedures require all six shim blade heights within two inches of each other?

a.

Maintains fuel integrity.

b.

Creates more fast neutrons.

c.

Dissipates residual gammas.

d.

Prevents an unbalanced power distribution.

Category C: Facility and Radiation Monitoring Systems QUESTION C.13

[1.0 point]

What instrumentation region is associated with the voltage is such that every primary ion produces an avalanche of secondary ions? This region also cannot differentiate between types of radiation.

a.

Region I, Recombination.

b.

Region II, Ionization.

c.

Region III, Proportional.

d.

Region IV, Geiger-Mueller.

QUESTION C.14

[1.0 point]

Which ONE of the following conditions will NOT activate the waste tanks alarm on the control room annunciator panel?

a.

A leak in the waste tank system.

b.

Ambient temperature below 320C.

c.

Waste tank filled with more than 900 gallons.

d.

Auxiliary building door is entered during reactor operations.

QUESTION C.15

[1.0 point]

The reference core condition is the reactivity condition of the core when the primary coolant and D2O reflector coolant temperatures are at ______ and the reactivity worth of xenon is ______.

a.

20 °C / 1.5 k/k.

b.

20 °C / 1.2 k/k.

c.

10 °C / 1.0 k/k.

d.

10 °C / 0.0 k/k.

Category C: Facility and Radiation Monitoring Systems QUESTION C.16

[1.0 point]

On indication of 1 µCi/liter of tritium in the secondary coolant water, the following action is NOT required:

a.

The cooling tower spray shall be shut down.

b.

The secondary system water discharge shall be stopped.

c.

The D2O reflector heat exchangers shall be isolated until tritium leakage into the secondary has been controlled.

d.

After Reactor and secondary coolant to D2O heat exchanger(s) are secured, the radiation monitor of Secondary Coolant channel shall be turn on.

QUESTION C.17

[1.0 point]

Which ONE of the following will initiate a reactor SCRAM? (Assume reactor is critical)?

a.

Reactor coolant outlet temperature is 50C.

b.

Core tank level is 4" below overflow pipe.

c.

The exhaust ventilation flow is 7510 cfm.

d.

Primary cleanup temperature is 52C.

QUESTION C.18

[1.0 point]

One of the requirements for testing the airlock gasket deflated scrams is that the reactor______.

a.

is in a shutdown condition b.

is at full maximum power level c.

is at or above reactor power level of 250 kW

d. is at or below reactor power level of 100 kW

Category C: Facility and Radiation Monitoring Systems QUESTION C.19

[1.0 point]

Which ONE of the following describes the function of Channel 7?

a.

Provides a linear indication of the flux level.

b.

Provides a reactor period indication if electrical power is lost.

c.

Provides a level signal to the nuclear safety system.

d.

Provides a signal based on system flows and temperatures.

QUESTION C.20

[1.0 point]

Thermal power output is based on a heat balance calculation derived from ______ and ______.

a.

Power and coolant level.

b.

Count rate and k-effective.

c.

Mass flow rates and temperature changes.

d.

Period rise and shutdown margin.

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

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

DOE Fundamentals of Reactor Theory, Volume 2, page 34

Category A: Reactor Theory, Thermodynamics, and Facility Operating Characteristics A.11 Answer:

d

Reference:

Burn, Introduction to Nuclear Reactor Operations, Section 8.1, page 8-1.

A.12 Answer:

a

Reference:

Burn, Introduction to Nuclear Reactor Operations, Section 6.2.3, page 6-4.

a

Reference:

P=Poet/Tt=T*ln(P/Po) assume constant period=1 The largest ratio of P/Po is the longest time to complete A.19 Answer:

a

Reference:

Burn, R., Introduction to Nuclear Reactor Operations, Sec 2.5.2, page 2-43.

A.20 Answer:

a. Reflector b. Reflector c. Absorber d. Poison

Reference:

DOE Fundamentals of Reactor Theory, Volume 2, Module 3 & 4

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

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

c

Reference:

MITR Technical Specifications 6.1.3 B.02 Answer:

c

Reference:

MITR PM Table 4.5.3-3 B.03 Answer:

d

Reference:

MIT PM 2.3.1(21)

10 CFR 55.59

MIT Facility Description Manual 4.2, RSM 4-4

MIT PM 2.4.2

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

ML24220A150

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