Text

Examination Report No. 50-20/OL-17-03, Massachusetts Institute of Technology
	ML17283A215
Person / Time
Site:	MIT Nuclear Research Reactor
Issue date:	10/11/2017
From:	Anthony Mendiola; Research and Test Reactors Oversight Projects Branch
To:	Queirolo A; Massachusetts Institute of Technology (MIT)
	JOHN T. NGUYEN
References
	50-020/OL-17-03
	Download: ML17283A215 (39)
	v • d • e

October 11, 2017 Mr. Al Queirolo, Director of Reactor Operations Massachusetts Institute of Technology 138 Albany Street Cambridge, MA 02139

SUBJECT:

EXAMINATION REPORT NO. 50-020/OL-17-03, MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Dear Mr. Queirolo:

During the week of September 4, 2017, the U.S. Nuclear Regulatory Commission (NRC) administered an operator licensing examination at your Massachusetts Institute of Technology reactor. The written examination and operating test 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 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. John T. Nguyen at (301) 415-4007 or via e-mail to John.Nguyen@nrc.gov.

Sincerely,

/RA/

Anthony Mendiola, Chief Research and Test Reactors Oversight Branch Division of Policy and Rulemaking Office of Nuclear Reactor Regulation Docket No.50-020

Enclosures:

1. Examination Report No. 50-020/OL-17-03

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

ML17283A215 OFFICE NRR/DLP/PROB:CE NRR/DIRS/IOLB:OLA NR/DLP/PROB:BC NAME JNguyen ABaxter AMendiola DATE 09/18/2017 10/10/2017 10/11/2017 Massachusetts Institute of Technology Docket No.50-020 cc:

City Manager City Hall Cambridge, MA 02139 Department of Environmental Protection One Winter Street Boston, MA 02108 Mr. Jack Priest, Director Radiation Control Program Department of Public Health 529 Main Street Schrafft Center, Suite 1M2A Charlestown, MA 02129 Mr. John Giarrusso, Chief Planning and Preparedness Division Massachusetts Emergency Management Agency 400 Worcester Road Framingham, MA 01702-5399 Test, Research and Training Reactor Newsletter P.O. Box 118300 University of Florida Gainesville, FL 32611-8300 Ms. Sarah M. Don, Reactor Superintendent Massachusetts Institute of Technology Nuclear Reactor Laboratory Research Reactor 138 Albany Street, MS NW12-116B Cambridge, MA 02139

U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.: 50-020/OL-17-03 FACILITY DOCKET NO.: 50-020 FACILITY LICENSE NO.: R-37 FACILITY: MITR-II EXAMINATION DATES: September 6 - 7, 2017 SUBMITTED BY: _________/RA/_________________ 09/21/2017 John T. Nguyen, Chief Examiner Date

SUMMARY

During the week of September 4, 2017 the NRC administered operator licensing examinations to three Reactor Operator candidates. The candidates passed all applicable portions of the examinations.

REPORT DETAILS

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

2. Results:

RO PASS/FAIL SRO PASS/FAIL TOTAL PASS/FAIL Written 3/0 0/0 3/0 Operating Tests 3/0 0/0 3/0 Overall 3/0 0/0 3/0

3. Exit Meeting:

Al Queirolo, Director of Reactor Operations, MIT Sarah Don, Superintendent of Reactor Operations, MIT Frank Warmsley, Training Supervisor, MIT John T. Nguyen, Chief Examiner, NRC The NRC examiner thanked the facility for their support in the administration of the examinations. The examiner noted that all candidates were well prepared for the examination.

Enclosure 1

U. S. NUCLEAR REGULATORY COMMISSION NON-POWER REACTOR LICENSE EXAMINATION FACILITY: Massachusetts Institute of Technology REACTOR TYPE: MITR II Research DATE ADMINISTERED: 9/7/2017 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 Enclosure 2

A. RX THEORY, THERMO & FAC OP CHARS ANSWER SHEET Multiple Choice (Circle or X your choice)

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

A01 a b c d ___

A02 a b c d ___

A03 a b c d ___

A04 a b c d ___

A05 a b c d ___

A06 a b c d ___

A07 a b c d ___

A08 a ___ b ___ c ___ d ___ (0.25 each)

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 ___

A20 a b c d ___

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

B. NORMAL/EMERG PROCEDURES & RAD CON ANSWER SHEET Multiple Choice (Circle or X your choice)

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

B01 a b c d ___

B02 a b c d ___

B03 a b c d ___

B04 a b c d ___

B05 a b c d ___

B06 a ___ b ___ c ___ d ___ (0.25 each)

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 ___ (0.25 each)

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 ___ (0.25 each)

B20 a b c d ___

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

C. PLANT AND RAD MONITORING SYSTEMS ANSWER SHEET Multiple Choice (Circle or X your choice)

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

C01 a b c d ___

C02 a b c d ___

C03 a b c d ___

C04 a b c d ___

C05 a b c d ___

C06 a b c d ___

C07 a ___ b ___ c ___ d ___ (0.25 each)

C08 a b c d ___

C09 a b c d ___

C10 a b c d ___

C11 a ___ b ___ c ___ d ___

e ___ f ___ g ___ h ___ (0.25 each)

C12 a b c d ___

C13 a b c d ___

C14 a b c d ___

C15 a b c d ___

C16 a b c d ___

C17 a b c d ___

C18 a b c d ___

C19 a b c d ___

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

EQUATION SHEET

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

(2 )

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

SUR = 26 .06

( )

CR1 1 K eff1 CR

= CR1 ((

2 1 1 )K

= CR )

eff 2 2 ( 2 )

(1 ) M=

1

= 2 CR P = P0 10SUR(t )

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

M= SDM = =

1 K eff 2 K eff

0.693 K eff 2 K eff1

+ T1 =

eff 2 K eff1 K eff 2 K eff 1

= DR = DR0 e t 2 DR1 d1 = DR2 d 2 2

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

R2 Peak2 Peak1 DR - Rem, Ci - curies, E - Mev, R - feet 1 Curie = 3.7 x 1010 dis/sec 1 kg = 2.21 lb 1 Horsepower = 2.54 x 103 BTU/hr 1 Mw = 3.41 x 106 BTU/hr 1 BTU = 778 ft-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, Thermo, and Fac. Operating Characteristics QUESTION A.01 [1.0 point]

The stable negative period following a scram is always the same value (- 80 second) regardless of initial power level. A reason is:

a. The nuclear instrument reads the constant count rate from a neutron source.

b. The rate of power change is dependent on a mean lifetime of the short lived delayed neutron precursors.

c. The delayed neutrons are born at same rate as prompt neutrons after shutdown resulting in a constant neutron count rate.

d. The rate of power change is dependent on a mean lifetime of the longest lived delayed neutron precursors.

QUESTION A.02 [1.0 point]

Given the following conditions:

Reactor is operating at 5 MW Scram setpoint is at 5.5 MW Scram delay time of 1 second Reactor period of 10 seconds What will be the approximate reactor power at the time of the scram due to this reactivity excursion?

a. 5.53 MW

b. 5.83 MW

c. 6.08 MW

d. 6.50 MW

Category A: Reactor Theory, Thermo, and Fac. Operating Characteristics QUESTION A.03 [1.0 point]

Which ONE of the following core arrangements (I through IV) would likely provide the most accurate fuel loading for the 1/M plot?

I. III.

II.

IV.

a. I

b. II

c. III

d. IV QUESTION A.04 [1.0 point]

The reactor is operating at 100 W with a fuel temperature of 60 °F. When a control rod with an average rod worth of 0.2% delta k/k/inch is withdrawn 5 inches, reactor power increases and becomes stable at a higher level. What is the final fuel temperature? Given the fuel temperature coefficient of reactivity of -1.25 E-4 k/k/ °F and ignoring any other temperature effects.

a. -20 °F

b. 20 °F.

c. 80 °F

d. 140 °F

Category A: Reactor Theory, Thermo, and Fac. Operating Characteristics QUESTION A.05 [1.0 point]

Which ONE of the following atoms will cause a neutron to lose the most energy in an elastic collision?

a. U-238

b. Ar-40

c. O-16

d. H-1 QUESTION A.06 [1.0 point]

Reactor A with a Keff of 0.1 and reactor B with a Keff of 0.8, Keff is increased by 0.1 for each reactor. The amount of reactivity added in reactor A is ______ in reactor B for the same increment.

a. less than

b. same

c. eight times

d. thirty-six times QUESTION A.07 [1.0 point]

The Reactor is critical at 100 watts. A reactor operator makes a mistake by inserting a sample worth of 1 beta into the reactor core. Which ONE of the following best describes the reactor kinetic?

a. Keff = 1 and = 0

b. Keff > 1 and = -eff

c. Keff < 1 and = 1 beta

d. Keff > 1 and 0 < < -eff

Category A: Reactor Theory, Thermo, and Fac. Operating Characteristics QUESTION A.08 [1.0 point, 0.25 each]

Match the following Neutron Interactions in Column A with the appropriate definition in Column B (each used only once)

Column A Column B

a. Fission 1. Neutron enters nucleus, forms a compound nucleus, then decays by gamma emission.

b. Radiative capture 2. Particle enters nucleus, forms a compound nucleus and is excited enough to eject a new particle with incident neutron remaining in nucleus.

c. Scattering 3. Nucleus absorbs neutron and splits into two similarly sized parts.

d. Particle ejection 4. Nucleus is struck by a neutron and emits a single neutron.

QUESTION A.09 [1.0 point]

A reactor contains a neutron source that produces 10,000 neutrons/second. The reactor has a keff = 0.80. What is the stable total neutron production rate in the reactor?

a. 20,000 neutrons/sec

b. 50,000 neutrons/sec

c. 80,000 neutrons/sec

d. 200,000 neutrons/sec QUESTION A.10 [1.0 point]

Which ONE of the following factors in the six factor formula is the MOST affected by the MODERATOR?

a. Fast fission factor

b. Reproduction factor

c. Thermal utilization factor

d. Resonance escape probability

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

Delayed neutrons are born at ________ energies than prompt neutrons which leads to the effective delayed neutron fraction being _______ than the delayed neutron fraction.

a. higher; higher

b. higher; lower

c. lower; lower

d. lower; higher QUESTION A.12 [1.0 point]

Reactor is in an automatic mode of 500 kW. What will the regulating rod do if its boron is replaced with void (air)?

a. Drive out to compensate a positive reactivity added

b. Drive out to compensate a negative reactivity added

c. Drive in to compensate a positive reactivity added

d. Drive in to compensate a negative reactivity added

Category A: Reactor Theory, Thermo, and Fac. Operating Characteristics QUESTION A.13 [1.0 point]

Which ONE of the following statements is true regarding to Xe-135 poison in the MITR reactor?

a. There are two methods forming Xe-135 poison: by decay of I-135 and decay of Cs-135.

b. As Xe-135 is formed in the reactor, the thermal utilization factor will increase.

c. Xe-135 can be formed directly as a fission product.

d. Xe-135 is never reach equilibrium during reactor operation.

QUESTION A.14 [1.0 point]

A reactor is subcritical with a shutdown margin of 5.0 % K/K. The addition worth is added and the count rate increases from 200 count per seconds to 400 count per seconds.

Which ONE of the following is the new Keff of the reactor?

a. 0.53

b. 0.90

c. 0.975

d. 1.02 QUESTION A.15 [1.0 point]

Which ONE of the following parameter changes will require the control rod INSERTION to maintain constant power level following the change?

a. Insertion of an experiment containing cadmium.

b. Adding of a fuel experiment (U-235) into the core.

c. Pool water temperature increase.

d. Buildup of Samarium in the core.

Category A: Reactor Theory, Thermo, and Fac. Operating Characteristics QUESTION A.16 [1.0 point]

What effect does Doppler Broadening for U-238 have on neutrons in a critical core?

a. More absorption

b. More scattering

c. Increasing the resonance escape probability

d. Increasing the Reproduction factor QUESTION A.17 [1.0 point]

Which ONE of the following is the stable reactor period which will result in a power rise from 1%

to 100% power in 1 minute?

a. 0.2 seconds

b. 5 seconds

c. 13 seconds

d. 80 seconds QUESTION A.18 [1.0 point]

Which ONE is true about subcritical multiplication? As the reactor approaches criticality, the parameter

a. keff approaches zero

b. approaches infinity

c. M approaches one

d. 1/M approaches zero

Category A: Reactor Theory, Thermo, and Fac. Operating Characteristics QUESTION A.19 [1.0 point]

Which ONE of the following isotopes has the HIGHEST thermal neutron cross section?

a. Cd-112

b. Sm-149

c. Xe-135

d. U-235 QUESTION A.20 [1.0 point]

If 200 millibeta of positive reactivity is suddenly introduced into a stable MITR-II core, what will be the steady period that is obtained? Assume the effective prompt neutron lifetime is 10-4 seconds and the effective delayed neutron decay constant is 0.1 s-1 and the effective delayed neutron fraction is 0.0078.

a. 9.6 seconds

b. 29 seconds

c. 40 seconds

d. 78.8 seconds

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

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

Annual limit on intake (ALI) means the derived limit for the amount of radioactive material taken into the body of an adult worker by inhalation or ingestion in a year. What is the regulatory limit on the committed effective dose equivalent for an individual in one year?

a. 50 mRem

b. 500 mRem

c. 5 Rem

d. 50 Rem QUESTION B.02 [1.0 point]

A survey instrument with a window probe is used to measure the beta-gamma dose rate from an irradiated experiment. The dose rate is 350 mrem/hour with the window opened and 100 mrem/hour with the window closed. The gamma dose rate is:

a. 450 mrem/hour

b. 350 mrem/hour

c. 250 mrem/hour

d. 100 mrem/hour QUESTION B.03 [1.0 point]

If the measured dose at the site boundary reads between 5 to 10 mRem/hr, this emergency event will be classified as:

a. Site Area Emergency

b. Alert

c. Notification of Unusual Events

d. AOP 5.6.2

Category B: Normal/Emergency Procedures and Radiological Controls QUESTION B.04 [1.0 point]

Which ONE of the following surveillances is a channel check?

a. Disconnecting the HV neutron flux channel to verify a reactor scram.

b. Comparing the readings of the continuous air monitors during reactor operation.

c. Exposing a check source to the radiation area monitor Reactor Floor #1, to verify its operation.

d. Adjusting a power level based on the thermal power calibration.

QUESTION B.05 [1.0 point]

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

a. Correctly determine the ECP calculation.

b. Allow the primary and secondary coolant to reach the desired flow for the heat exchanger requirement.

c. Allow the core and the primary coolant to reach thermal equilibrium for reducing stress on fuel cladding.

d. Adjust the power level based on the thermal power calibration.

QUESTION B.06 [1.0 point, 0.25 each]

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

Column A Column B

a. Add more responsibilities to the Radiation 1. Class A Protection Officer listed in PM 1.1.3

b. Delete BNCT Facility Beams listed 2. Class B in Technical Specifications

c. Make a minor change to Technical Specifications

3. Class C

d. Replace primary cooling pump

Category B: Normal/Emergency Procedures and Radiological Controls QUESTION B.07 [1.0 point]

The MITR safety functions can be bypassed either by key switch bypasses or jumpers. Which ONE of the following is the correct statement for the bypass?

a. Safety functions required by Technical Specifications as a Limiting Condition for Operation may be temporarily bypassed for testing purposes with a condition that the bypasses must be approved by the U.S. NRC.

b. All of the bypasses must be authorized by the Reactor Superintendent ONLY.

c. The physical installation of a bypass must be checked after installation by two responsible persons.

d. The maximum power to conducting a bypass is 1 MW.

QUESTION B.08 [1.0 point]

A semi-annual test of the nuclear instrument was performed. Which ONE of the following is the latest the test that must be performed again without violation of the Technical Specifications?

a. 6 months

b. 7 months

c. 8 months

d. 12 months QUESTION B.09 [1.0 point]

A radiation from an unshielded source is 100 mrem/hr. What is a radiation level when shielding it with a lead sheet of 20 mm thickness? Given the half-value-layer (HVL) of lead = 10 mm.

a. 10 mem/hr

b. 25 mrem/hr

c. 50 mrem/hr

d. 75 mrem/hr

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

Which ONE of the following is the definition of Total Effective Dose Equivalent (TEDE)?

a. The sum of thyroid dose and external dose.

b. The sum of the external deep dose and the organ dose.

c. The sum of the deep dose equivalent and the committed effective dose equivalent.

d. The dose that your whole body is received from the source, but excluded from the deep dose.

QUESTION B.11 [1.0 point]

After a long period of reactor operation, the staffs perform a normal shutdown checklist and find that all the control rods are fully inserted except the regulating rod. Which ONE of the following is the MINIMUM staffing requirement for this condition? Assume that the Radiation Protection Officer is available at all time.

a. All staffs may go home after the shutdown checklist is completed because the reactor meets a shutdown definition.

b. Require only one licensed reactor operator (RO) present in the control room.

c. Require one SRO onsite and one RO in the control room.

d. Require one SRO in the control room and two staffs onsite.

QUESTION B.12 [1.0 point]

A room contains a source which, when exposed, results in a general area dose rate of 300 millirem per hour. This source is scheduled to be exposed continuously for 10 days. Which ONE of the following statements correctly describes an acceptable method for controlling radiation exposure from the source within this room?

a. Monitor the current dose rate in the reactor control room.

b. Post the area with Caution - Radiation Area.

c. Control is not required because the presence of radioactive source is less than 30 days.

d. Equip the room with an electronic surveillance that is capable of preventing unauthorized entry.

Category B: Normal/Emergency Procedures and Radiological Controls QUESTION B.13 [1.0 point, 0.25 each]

Match the appropriate radiation unit in Column A with its definition in Column B.

Column A Column B

a. Curie 1. Equal to absorbed dose of 100 ergs/gram

b. Roentgen 2. Amount of radioactive material decaying at a rate of 3.7x1010

c. RAD 3. Amount of x-ray or gamma ray leading to the absorption of 88 ergs/gram in air

d. Dose Equivalent 4. Equal to absorbed dose in RAD times quality factor QUESTION B.14 [1.0 point]

Which ONE of the following best describes the reactor conditions if both door gaskets of the main personnel air lock are deflated simultaneously?

Column B

a. A Low Pressure Personnel Lock alarm ONLY

b. A Main Personnel Airlock Gaskets Deflated alarm ONLY

c. A Low Pressure Personnel Lock alarm + a Main Personnel Airlock Gaskets Deflated alarm + reactor interlock

d. A Low Pressure Personnel Lock alarm + a Main Personnel Airlock Gaskets Deflated alarm + reactor scram QUESTION B.15 [1.0 point]

During a reactor startup you reach 0.5 inches above the Estimate Critical Position for the Shim Bank and the reactor is still subcritical. Which one of the following action is INCORRECT?

a. Recheck sample reactivates.

b. If no discrepancy found, notify the Superintendent.

c. Immediately drive bank in to 1.0" or more below ECP.

d. Drive each blade out and check neutron level to ensure blade coupled.

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

During a reactor operation, one of the plenum radiation monitors has failed and causing the ventilation tripped. What must be done in order to continue operation?

a. Ignoring its failing channel and try to restart the ventilation.

b. Selecting a different plenum channel and restart the ventilation.

c. Bypass affected channel using key switch and restart the ventilation.

d. MITR Technical Specifications requires all plenum monitor in operation.

QUESTION B.17 [1.0 point]

All applicants for an RO or SRO license must take the NRC examination according to the requirement of 10 CFR :

a. Part 19

b. Part 20

c. Part 50

d. Part 55 QUESTION B.18 [1.0 point]

Per MITR Technical Specifications, the maximum conductivity of the primary coolant at 20 ºC is:

a. 2 µS/cm

b. 5 µS/cm

c. 8 µS/cm

d. 10 µS/cm

Category B: Normal/Emergency Procedures and Radiological Controls QUESTION B.19 [1.0 points, 0.25 each]

Match the radiation reading from Column A with its corresponding radiation area classification (per 10 CFR 20) listed in Column B. Answer in Column B can be used more than once, or not at all.

Column A Column B

a. 2 mrem/hr at 1 m 1. Public Area

b. 20 mrem/hr at 1 m 2. Radiation Area

c. 50 mrem/hr at 1 m 3. High Radiation Area

d. 5.5 grays/hr at 1 m 4. Very High Radiation Area QUESTION B.20 [1.0 point]

Which ONE of the following radionuclide causes a severe damage to thyroid gland from an intake?

a. I131

b. N16

c. Ar41

d. Co60

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

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

When a leak detected by a leak tape occurs from the primary and D2O system, a leak alarm will activate. The leak alarm can be cleared by:

a. Replacing with the new tape.

b. Lowering reactor power to 250 kW.

c. Pressing the acknowledge alarm button.

d. Shutting HV-16A and the secondary blowdown valve.

QUESTION C.02 [1.0 point]

The voltage scram associated with the compensated ion chamber is set to trip if:

a. The compensating voltage is lost.

b. The batteries are disconnected from the emergency electrical power distribution panel.

c. The voltage becomes too high, driving the detector into the continuous discharge region.

d. The voltage drops below the value required to maintain the detector in the ion chamber plateau region.

QUESTION C.03 [1.0 point]

You receive a Low Level Core Tank alarm. It means:

a. Both primary pumps have tripped.

b. A loss of coolant from primary system has occurred.

c. A pressure drop across the primary systems flow nozzle has occurred.

d. A pressure loss from city water to the ECCS system has occurred.

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

How is the air compressor CM-2 protected if an overpressure (200 psi) has occurred?

a. A control valve (CV-16) will relieve pressure to the atmosphere.

b. A control valve (CV-121) will relieve pressure to the backup CM-1.

c. A design of the CM-2 system can maintain an overpressure for 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

d. An overpressure signal will automatically shut an electrical power distributed to the CM-2 system.

QUESTION C.05 [1.0 point]

Per AOP procedure, the reactor will have an _______ when a MINIMUM shield flow exceeds

a. Automatic scram / 50 gpm

b. Automatic scram / 60 gpm

c. Interlock / 50 gpm

d. Interlock / 60 gpm QUESTION C.06 [1.0 point]

On a startup within 16 hours1.851852e-4 days 0.00444 hours 2.645503e-5 weeks 6.088e-6 months of shutdown, you are required to check all of the listed below for Channel #2 operation, EXCEPT:

a. Amplifier on and select audible signal to monitor Ch.2

b. Ch.2 neutron counter on

c. High Voltage trip

d. Gain and discrimination settings are acceptable

Category C: Facility and Radiation Monitoring Systems QUESTION C.07 [1.0 point, 0.25 each]

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

Column A Column B

a. Reactor power on Channel # 8 = 5.2 MW 1. Normal or indication only

b. High Temperature Reactor Outlet Recorder = 56 °C 2. Interlock

c. Dump valve open 3. Rod Run Down

d. Medical Water Shutter System alarm 4. Scram QUESTION C.08 [1.0 point]

Which ONE of the following is NOT a concern on a loss of compressed air?

a. Operability of the pneumatic tube sample ejection system.

b. Capability to monitor dump tank level remotely.

c. Main personnel lock door gaskets.

d. Containment integrity.

QUESTION C.09 [1.0 point]

Which ONE of the following is a water source for the shield coolant system?

a. Directly from a city water system.

b. Water from the H2O shutter tank.

c. Demineralized water from storage tank.

d. Water from the emergency core cooling system (ECCS).

Category C: Facility and Radiation Monitoring Systems QUESTION C.10 [1.0 points]

Per PM 3.3.2, Spent Fuel Removal, the operator in the control room would be required to notify personnel on the reactor top, if:

a. A spare portable light turns off.

b. Sustain increases in radiation level.

c. A negative 80-second period is observed.

d. A sudden decrease of subcritical multiplication factor.

QUESTION C.11 [2.0 points, 0.25 each]

Match each monitor and instrument (channel) listed in column A with a specific purpose in column B. Items in column B is to be used only once.

Column A Column B

a. Stack Gas monitor 1. Monitor radiation level in the reactor top

b. Plenum Particulate monitor 2. Detect radioisotopes released due to fuel failure

c. High Level Emergency Power Channel 3. Determine the effluent of Ar-41 (HLEPC)

d. Portable monitor 4. Survey of laboratory e Log Count-Rate channel 5. Monitor neutron level during the reactor startup

f. Area radiation monitor 6. Provide a period scram

g. Log N Period (Chanel 3) 7. Provide a high power level scram

h. Power Level (Chanel 4) 8. Provide indication of the reactor power level when all off-site electrical power has been lost

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

The primary concern associated with the pressure relief system charcoal filters becoming submersed during a large leak of primary coolant is:

a. Loss of efficiency in removing particulates.

b. Possible spontaneous combustion during dryout.

c. Reduction in relief flow capability to relieve pressure.

d. Possible spread of contamination from leaks in the filter housing.

QUESTION C.13 [1.0 point]

The MIT Thermal Power Calibration is calculated by:

a. measuring the neutron flux in a beam port at power.

b. irradiating gold foils and counting to determine power level.

c. performing a heat balance with the reactor at power and in equilibrium.

d. obtaining a tank water temperature constant (tank water temperature rises at 1 MW-Hr).

QUESTION C.14 [1.0 point]

Per MITR Technical Specifications, to prevent a flammable concentration of H 2 gas, the maximum limit of H2 concentration in the air space above the core is ______.

a. 2.5 %

b. 3.5 %

c. 4.5 %

d. 5.5 %

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

Which ONE of the following is the correct formula for calculating the thermal power hourly on the reactor operating data log? The total power is equal to:

a. Primary power + Reflector power + Shield power.

b. Primary power - Reflector power + Shield power.

c. Primary power - Reflector power - Shield power.

d. Primary power + Reflector power - Shield power.

QUESTION C.16 [1.0 point]

The following conditions (if activated) will cause the weekend alarm, EXCEPT?

a. Smoke detector system.

b. Low level core tank.

c. Low pressure helium supply.

d. Reactor control room temperature.

QUESTION C.17 [1.0 point]

Which ONE of the following is the purpose for the subcritical interlock?

a. To prevent the reactor from being manipulated to a critical position before the startup channels are switched from fission chambers to uncompensated ion chambers.

b. To maintain the shim blade bank programmed at a uniform height during final approach to criticality.

c. To make a complete instrument check before bringing the reactor from criticality to full power.

d. To ensure that a steady rate of startup to the critical position is achieved.

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

There consists a leak developed within any of the heat exchanger serviced by the secondary water system. Which ONE of the following nuclides will be seen by the detector in the secondary water system? Assume that no fuel element failure.

a. Xe135

b. Ar41

c. I 131

d. F18 QUESTION C.19 [1.0 point]

The function of the discriminator of fission chamber is used to:

a. distinguish the large pulses created by fission from smaller pulses produced by the gamma rays.

b. distinguish pulses created by fission from pulses produced by alpha from (B-10 + n Li-7 + ) reaction.

c. converting pulses created by fission to a current signal (µA).

d. distinguish the large pulses created by the valence band from smaller pulses created by the conduction band.

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

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

Category A: Theory, Thermo & Fac. Operating Characteristics A.01 Answer: d

Reference:

P = P0 et/T P = 5.5 MW

e 1/10 P= 6.08 MW A.03 Answer: b

Reference:

Lecture 3-1 from Dr. Bernard (MIT)

A.04 Answer: d

Reference:

Reactivity added by control rod = +(0.002 k/k/inch)((5 inches) = 0.01 k/k Fuel temperature change = - reactivity of rod/fuel temp. coeff.

(- 0.01 k/k)/(- 1.25E-4 k/k/°F) = 80 °F Final Fuel temperature = 60 °F +80 °F = 140 °F A.05 Answer: d

Reference:

reactor A = (Keff1-Keff2)/(Keff1*Keff2). (0.2-0.1)/(0.2*0.1) = 5 k/k reactor B = (Keff1-Keff2)/(Keff1*Keff2). (0.9-0.8)/(0.9*0.8) = 0.139 k/k 5/0.139 = 36 A.07 Answer: b

Reference:

DOE Fundamentals Handbook Nuclear Physics and Reactor Theory, Volume 1, Module 1, Page 43-46 A.09 Answer: b

Reference:

SCR = (S)/ (1-Keff )

N = (10,000)/(1-0.8) = 50,000 neutrons/second DOE Fundamentals Handbook, NPRT, Vol. 2, Module 4, EO 1.2, p 4

Category A: Theory, Thermo & Fac. Operating Characteristics A.10 Answer: c

Reference:

A.11 Answer: d

Reference:

SDM = (1-Keff)/Keff Keff = 1/(SDM + 1) = 1/(.05` + 1) Keff = 0.95 CR1/CR2 = (1 - Keff2) / (1 - Keff1) 200/400 = (1 - Keff2) / (1 - 0.95)

(0.5) x (0.05) = (1 - Keff2) Keff2 = 1 - (0.5)(0.05) = 0.975 A.15 Answer: b

Reference:

Adding U-235 means adding of a positive reactivity to the core, so you need to insert the control rod to maintain the same power A.16 Answer: a

Reference:

P = P0 et/T --> T= t/Ln(P/ P0 )

T= 60/Ln(100 ); T = 13 sec.

A.18 Answer: d

Reference:

Burn, R., Introduction to Nuclear Reactor Operations, 1988, Table 5.5

Category A: Theory, Thermo & Fac. Operating Characteristics A.19 Answer: c

Reference:

A.20 Answer: c

Reference:

=

eff

= 0.2 beta

0.0078 = 0.00156 T = (0.0078 - 0.00156)/(0.1*.00156)

T = 40 seconds

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

Reference:

10 CFR 20.1003 B.02 Answer: d

Reference:

Basic radiation instrumentation B.03 Answer: c

Reference:

PM 4.4.4.14 B.04 Answer: b

Reference:

TS 3.2.2 B.05 Answer: c

Reference:

PM 2.3.1 - Step 21 B.06 Answer: a(2) b(1) c(1) d(2)

Reference:

PM 1.4 B.07 Answer: c

Reference:

PM 2.2.3 and PM 1.9 B.08 Answer: b

Reference:

TS Definition, Frequency Not exceed: 25% of 6 months + 6 months = 7.5 months B.09 Answer: b

Reference:

From 100mrem to 50 mrem required 10 mm of lead sheet From 50 mrem to 25 mrem required another 10 mm of lead sheet So 20mm of lead sheet will reduce a radiation from 100 mrem/hr to 25 mrem/hr B.10 Answer: c

Reference:

10 CFR 20.1003 B.11 Answer: c

Reference:

TS 7.1.3.2 B.12 Answer: d

Reference:

10 CFR 20.1601(b)

Category B: Normal/Emergency Procedures and Radiological Controls B.13 Answer: a (2) b(3) c(1) d(4)

Reference:

NRC Standard Question B.14 Answer: d

Reference:

RSM 8.6 B.15 Answer: d

Reference:

PM 2.3 B.16 Answer: c

Reference:

AOP 5.6.3 B.17 Answer: d

Reference:

10 CFR 55 B.18 Answer: d

Reference:

TS 3.3.6 B.19 Answer: a(2); b(3); c(3); d(4)

Reference:

10 CFR 20.1003 Definitions 2 mrem/hr at 1 m = 22.2 mrem/hr at 30 cm => Radiation area 50 mrem/hr at 1m = 0.55 rem/hr at 30 cm => high radiation area 20 mrem/hr at 1m will be equal to 222 mrem/hr at 30 cm :=> high radiation area 5.5 grays 550 rad/hr at 1 m very high radiation area Definition High Radiation Area: 100 mrem/hr at 30 cm Radiation Area : 5 mrem/hr at 30 cm Very High Radiation Area: 500 rads/hr at 1 m B.20 Answer: a

Reference:

Basic Health Physics

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

Reference:

PM 5.2.14 C.02 Answer: d

Reference:

PM 5.1.5 C.03 Answer: b

Reference:

PM 5.2.3 C.04 Answer: a

Reference:

RSM 8.6.1 C.05 Answer: b

Reference:

RSM 6.5.7 C.06 Answer: c

Reference:

PM 3.1.1.2 C.07 Answer: a(1) b(4) c(4) d(1)

Reference:

PM 5.1.1, PM5.2.6, and RSM Table 6.1 C.08 Answer: a

Reference:

RSM 2.5 and 8.6 C.09 Answer: c

Reference:

PM 5.4.1.2 C.10 Answer: b

Reference:

PM 3.3.2 C.11 Answer: a(3) b(2) c(8) d(4) e(5) f(1) g(6) h(7 )

Reference:

RSM 5-3 and TS 4.3 C.12 Answer: b

Reference:

PM 5.2.14

Category C: Facility and Radiation Monitoring Systems C.13 Answer: c

Reference:

SOP, PM 2.4.2 C.14 Answer: b

Reference:

TS 3.3.2 C.15 Answer: a

Reference:

PM 2.4.2 C.16 Answer: d

Reference:

RSM 9.5 C.17 Answer: b

Reference:

RSM 4.2 C.18 Answer: d

Reference:

RSM 7.4.1 C.19 Answer: a

Reference:

RSM 5.2.1

ML17283A215

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SUBJECT:

Dear Mr. Queirolo:

Enclosures:

SUMMARY

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