Text

Examination Report No. 50-020/OL-14-01, Massachusetts Institute of Technology
	ML14045A243
Person / Time
Site:	MIT Nuclear Research Reactor
Issue date:	02/27/2014
From:	Gregory Bowman; Research and Test Reactors Branch B
To:	Moncton D; Massachusetts Institute of Technology (MIT)
	P Isaac, 301-415-1019
Shared Package
ML13352A300	List: ML13352A272; ML14045A197; ML14045A243;
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	50-020/14-01 50-020/OL-14-01
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February 27, 2014 Dr. David E. Moncton, Director of the Nuclear Reactor Laboratory Massachusetts Institute of Technology 138 Albany Street Mail Stop NW 12-208 Cambridge, MA 02139

SUBJECT:

EXAMINATION REPORT NO. 50-020/OL-14-01, MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Dear Dr. Moncton:

During the week of February 3, 2014, the U.S. Nuclear Regulatory Commission (NRC) administered an operator licensing examination at your Massachusetts Institute of 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 NRCs 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. Patrick Isaac at (301) 415-1019 or via internet e-mail Patrick.Isaac@nrc.gov.

Sincerely,

/RA/

Gregory T. Bowman, Chief Research and Test Reactors Oversight Branch Division of Policy and Rulemaking Office of Nuclear Reactor Regulation Docket No. 50-20

Enclosures:

1. Examination Report No. 50-020/OL-14-01

2. Facility Comment and NRC Resolution

3. Administered written examination cc: Frank Warmsley w/o enclosures: See next page

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 Beverly Anderson, Interim Director Radiation Control Program Department of Public Health Schrafft Center, Suite 1M2A 529 Main Street Charlestown, MA 02129 John Giarrusso, Planning and Preparedness Division Chief Massachusetts Emergency Management Agency 400 Worcester Road Framingham, MA 01702-5399 Test, Research, and Training Reactor Newsletter University of Florida 202 Nuclear Sciences Center Gainesville, FL 32611

February 27, 2014 Dr. David E. Moncton, Director of the Nuclear Reactor Laboratory Massachusetts Institute of Technology 138 Albany Street Mail Stop NW 12-208 Cambridge, MA 02139

SUBJECT:

EXAMINATION REPORT NO. 50-020/OL-14-01, MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Dear Dr. Moncton:

During the week of February 3, 2014, the U.S. Nuclear Regulatory Commission (NRC) administered an operator licensing examination at your Massachusetts Institute of 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 NRCs 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. Patrick Isaac at (301) 415-1019 or via internet e-mail Patrick.Isaac@nrc.gov.

Sincerely,

/RA/

Gregory T. Bowman, Chief Research and Test Reactors Oversight Branch Division of Policy and Rulemaking Office of Nuclear Reactor Regulation Docket No. 50-20

Enclosures:

1. Examination Report No. 50-020/OL-14-01

2. Facility Comment and NRC Resolution

3. Administered written examination cc: Frank Warmsley w/o enclosures: See next page DISTRIBUTION PROB r/f RidsNrrDprPrta RidsNrrDprPrtb ADAMS ACCESSION No.: ML14045A243 NRR-074 OFFICE NRR/DPR/PROB NRR/DPR/PROB NRR/DPR/PROB NAME PIsaac CRevelle GBowman DATE 2/12/14 2/27/14 2/27/14 OFFICIAL RECORD COPY

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

50-20/OL-14-01 FACILITY DOCKET NO.:

50-20 FACILITY LICENSE NO.:

R-37 FACILITY:

MITR-II EXAMINATION DATES:

February 4 - 5, 2014 SUBMITTED BY:

______/RA/______________

__02/20/2014__

Patrick Isaac, Chief Examiner Date

SUMMARY

During the week of February 3, 2014, the NRC administered operator licensing examinations to one Senior Reactor Operator (SROI) and one Reactor Operator (RO) candidate. The candidates passed all portions of the examinations.

REPORT DETAILS

1.

Examiners: Patrick Isaac, Chief Examiner, NRC

2.

Results:

RO PASS/FAIL SRO PASS/FAIL TOTAL PASS/FAIL Written 1/0 1/0 2/0 Operating Tests 1/0 1/0 2/0 Overall 1/0 1/0 2/0

3.

Exit Meeting:

Patrick Isaac, Chief Examiner, NRC Frank Warmsley, Training Supervisor, MIT The Chief Examiner agreed with Mr. Warmsley to delete question B.8 from the written examination. The question did not include a correct answer. In addition, Mr. Wormsley recommended a change to the answer key for question A.16. His comment and the NRCs resolution to it are addressed in Enclosure 2. There were no generic concerns raised by the examiners.

ENCLOSURE 2 FACILITY COMMENT AND NRC RESOLUTION Question A.16 The reactor is shutdown after an extended, 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , run at 240 kilowatts. Which one of the following is the time it takes for the MAXIMUM Xenon concentration to be achieved?

a.

0 to 1 hours1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months

b.

2 to 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months

c.

8 to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

d.

18 to 22 hours2.546296e-4 days 0.00611 hours 3.637566e-5 weeks 8.371e-6 months Answer:

c

Reference:

While the correct answer at many facilities is c, 8-12 hours, at the MIT reactor, we have found that our Xenon peaks after 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months . This can be easily seen on the Xenon after shutdown graph I have enclosed for you.

It was previously thought the reason was due to our hard photo neutron source from the large amount of heavy water surrounding the core, however, Dr. Bernard has said that that does not seem reasonable, and that it would be a nice PhD thesis for why it is like that here.

NRC Resolution A.16:

Comment accepted. The answer key for A.16 has been modified to accept option b as correct.

ENCLOSURE 3 U. S. NUCLEAR REGULATORY COMMISSION NON-POWER REACTOR INITIAL LICENSE EXAMINATION FACILITY:

MIT REACTOR TYPE:

MITR-II DATE ADMINISTERED: 2/4/2014 CANDIDATE:

INSTRUCTIONS TO CANDIDATE:

Answers are to be written on the answer sheet provided. Attach the answer sheets to the examination. Points for each question are indicated in parentheses for each question. 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 CANDIDATES SCORE

% OF CATEGORY VALUE CATEGORY 20.0 33.3 A. REACTOR THEORY, THERMODYNAMICS, AND FACILITY OPERATING CHARACTISTICS 20.0 33.3 B. NORMAL AND EMERGENCY OPERATING PROCEDURES AND RADIOLOGICAL CONTROLS 20.0 33.3 C. FACILITY AND RADIATION MONITORING SYSTEMS 60.00 FINAL GRADE TOTALS ALL THE 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.

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

°F = 9/5 °C + 32 1 gal (H2O) 8 lbm

°C = 5/9 (°F - 32) cP = 1.0 BTU/hr/lbm/°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

x

=

+

=

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

=

+

=

eff 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

1 1

d DR d

DR

=

T UA H

m T

c m

Q P

=

)

20 30 40 50 60 50 55 60 65 70 75 80 Reactor Outlet Temperature, Tout (°C) 10 feet (3 meters) 6 feet (1.8 meters)

Coolant Height, H Fcore FrFH RFfdf 1

= 2.4 P

WP x104 MW gpm

A. RX THEORY, THERMO & FAC OP CHARS 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.

MULTIPLE CHOICE 001 a b c d ___

002 a b c d ___

003 a b c d ___

004 a b c d ___

005 a b c d ___

006 a b c d ___

007 a b c d ___

008 a b c d ___

009 a b c d ___

010 a b c d ___

011 a b c d ___

012 a b c d ___

013 a b c d ___

014 a b c d ___

015 a b c d ___

016 a b c d ___

017 a b c d ___

018 a b c d ___

019 a b c d ___

020 a b c d ___

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

B. NORMAL/EMERG PROCEDURES & RAD CON 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.

MULTIPLE CHOICE 001 a b c d ___

002 a b c d ___

003 a b c d ___

004 a b c d ___

005 a b c d ___

006 a b c d ___

007 a b c d ___

008 a b c d ___

DELETED 009 a b c d ___

010 a b c d ___

011 a b c d ___

012 a b c d ___

013 a b c d ___

014 a b c d ___

015 a b c d ___

016 a b c d ___

017 a b c d ___

018 a b c d ___

019 a b c d ___

020 a b c d ___

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

C. PLANT AND RAD 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.

MULTIPLE CHOICE 001 a b c d ___

002 a b c d ___

003 a b c d ___

004 a b c d ___

005 a ___ b ___ c ___ d ___

e ___ f ___ g ___ h ___

006 a b c d ___

007 a b c d ___

008 a b c d ___

009 a b c d ___

010 a b c d ___

011 a b c d ___

012 a ___ b ___ c ___

013 a b c d ___

014 a b c d ___

015 a b c d ___

016 a b c d ___

017 a b c d ___

018 a b c d ___

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

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

Section A _ Theory, Thermo & Fac. Operating Characteristics QUESTION (A.1)

[1.0]

Shortly after a reactor trip, reactor power indicates 0.5% where a stable negative period is attained.

Reactor power will be reduced to 0.05% in approximately _______ seconds.

a.

90

b.

180

c.

270

d.

360 QUESTION (A.2)

[1.0]

The following data was obtained during a reactor fuel load.

No. of Elements Detector A (cps) 0 20 8

28 16 30 24 32 32 42 40 80 Which one of the following represents the number of fuel elements predicted to reach criticality?

a.

48

b.

52

c.

56

d.

60 QUESTION (A.3)

[1.0]

An initial count rate of 100 is doubled five times during startup. Assuming an initial Keff = 0.950, what is the new Keff?

a.

0.957

b.

0.979

c.

0.988

d.

0.998

Section A _ Theory, Thermo & Fac. Operating Characteristics QUESTION (A.4)

[1.0]

Which one of the following is the MAXIMUM amount of reactivity that can be promptly inserted into the reactor WITHOUT causing the reactor to go "Prompt Critical"?

a.

100 m

b.

500 m

c.

750 m

d.

1900 m QUESTION (A.5)

[1.0]

The reactor is shut down by 0.05 K/K, this would correspond to Keff of:

a.

0.9995.

b.

0.9524.

c.

0.7750.

d.

0.0500.

QUESTION (A.6)

[1.0]

Which one of the following is the effect due to an INCREASE in water temperature?

a.

Neutron spectrum hardens due to less moderation.

b.

Neutron spectrum softens due to increased leakage.

c.

Reactivity increases due to less leakage.

d.

Reactivity decreases due to more moderation.

Section A _ Theory, Thermo & Fac. Operating Characteristics QUESTION (A.7)

[1.0]

A reactor is subcritical with a shutdown margin of 0.0526 K/K. The addition of a reactor experiment increases the indicated count rate from 10 cps to 20 cps. Which one of the following is the new Keff of the reactor?

a.

.53

b.

.90

c.

.975

d.

1.02 QUESTION (A.8)

[1.0]

Which one of the following statements describes how fuel temperature affects the core operating characteristics?

a.

Fuel temperature increase will decrease the resonance escape probability.

b.

Fuel temperature decrease results in Doppler Broadening of U238 and Pu240 resonance peaks and the decrease of resonance escape probability.

c.

Decrease in fuel temperature will increase neutron absorption by U238 and Pu240.

d.

Fuel temperature increase results in Doppler Broadening of U238 and PU240 resonance peaks and the decrease of neutron absorption during moderation.

QUESTION (A.9)

[1.0]

Which statement illustrates a characteristic of Subcritical Multiplication?

a.

As Keff approaches unity (1), for the same increase in Keff, a greater increase in neutron population occurs.

b.

The number of neutrons gained per generation gets larger for each succeeding generation.

c.

The number of fission neutrons remain constant for each generation.

d.

The number of source neutrons decreases for each generation.

QUESTION (A.10)

[1.0]

Select the statement that describes why neutron sources are used in reactor cores.

a.

Increase the count rate by an amount equal to the source contribution.

b.

Increase the count rate by 1/M (M = Subcritical Multiplication Factor).

c.

Provide adequate excess reactivity for experiments.

d.

Provide a neutron level high enough to be monitored by source range instrumentation.

Section A _ Theory, Thermo & Fac. Operating Characteristics QUESTION (A.11)

[1.0]

With the reactor critical at 50% power, the reactor operator withdraws the regulating rod. As power increases, a stable doubling time (DT) of 24 seconds is recorded. (Assume a of 0.1 sec-1 and a of.0070) Which one of the following is the reactivity added to the core by the operator?

a.

0.14% K/K

b.

0.16% K/K

c.

0.18% K/K

d.

0.20% K/K QUESTION (A.12)

[1.0]

The term "Shutdown Margin" describes:

a.

the time required for the blades to fully insert

b.

the departure from Keff = 1.00

c.

the amount of reactivity by which the reactor is subcritical

d.

the amount of reactivity inserted by all the rods except the most reactive blade and the regulating rod.

Section A _ Theory, Thermo & Fac. Operating Characteristics QUESTION (A.13)

[1.0]

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

a.

Thermal neutrons

b.

Fast neutrons

c.

Gamma rays

d.

X-rays QUESTION (A.14)

[1.0]

Assuming the Samarium worth is 0.006 K/K at full power, which one of the following is the Samarium worth 10 days after shutdown from full power?

a.

Essentially zero.

b.

It increases by a factor of 2.

c.

Less than 0.006 K/K but greater than zero.

d.

Greater than 0.006 K/K QUESTION (A.15)

[1.0]

Which one of the following factors is the most significant in determining the differential worth of a control rod?

a.

The rod speed.

b.

Reactor power.

c.

The flux shape.

d.

The amount of fuel in the core.

QUESTION (A.16)

[1.0]

The reactor is shutdown after an extended, 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , run at 240 kilowatts. Which one of the following is the time it takes for the MAXIMUM Xenon concentration to be achieved?

a.

0 to 1 hours1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months

b.

2 to 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months

c.

8 to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

d.

18 to 22 hours2.546296e-4 days 0.00611 hours 3.637566e-5 weeks 8.371e-6 months

Section A _ Theory, Thermo & Fac. Operating Characteristics QUESTION (A.17)

[1.0]

The MIT Reactor is operating at 5 MW and the reactor scram is set for 110% of full power. What will be the power at the time of the scram if a nuclear excursion creates a 0.5 second period and the scram delay time is 1.0 second after 110% is reached?

a.

9 MW

b.

15 MW

c.

32 MW

d.

40 MW QUESTION (A.18)

[1.0]

Which one of the following is the reason why it takes approximately 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of constant power operation before thermal equilibrium is attained in the MITR-II reactor?

a.

The time required for equilibrium Xenon and Samarium conditions to be established.

b.

The time required for the large volume of the Deuterium tank to heat up.

c.

The graphite reflector has a large heat capacity and is slow to reach equilibrium temperature distribution.

d.

The shield coolant system has a small flowrate to accomplish adequate mixing before temperature is uniformly stabilized.

QUESTION (A.19)

[1.0]

The reactor has been operating at 100% power for the past 20 days. Which one of the following is the primary source of heat generation in the core 30 SECONDS following a reactor scram from 100% power?

a.

Fission from the longest lived delayed neutron precursors.

b.

Fission resulting from installed source neutrons.

c.

Beta and gamma heating from fission decay products.

d.

Beta and gamma heating from fission generated by installed neutron sources.

Section A _ Theory, Thermo & Fac. Operating Characteristics QUESTION (A.20)

[1.0]

Which one of the following statements is FALSE?

a.

An increasing concentration in the reactor core of Xe-135 reduces the thermal utilization factor, f, and hence the multiplication factor, Keff, of the reactor core.

b.

Xe-135 is produced both directly as a fission product and as the result of a decay chain from other fission products.

c.

A good approximation for determining the production in a reactor core of Xe-135 is to assume that the Xe-135 is produced from the decay of Cs-135.

d.

The removal rate of Xe-135 is due to the neutron absorption rate in Xe-135 atoms and due to the radioactive decay of Xe-135 atoms.

(*** End of Section A ***)

Section B Normal/Emerg. Procedures & Rad Con QUESTION (B.1)

[1.0]

Administrative Procedure 1.10.8 requires the use of tongs at least 6 inches long to handle irradiated rabbit samples. The reason for this control is the probable high

a.

alpha radiation levels

b.

beta radiation levels

c.

gamma radiation levels

d.

surface temperature of the polyethylene container QUESTION (B.2)

[1.0]

A small radioactive source is to be stored in the reactor bay with no shielding. The source reads 2 R/hr at 1 foot. A Radiation Area barrier would have to be erected approximately ___ from the source.

a.

400 feet

b.

40 feet

c.

20 feet

d.

10 feet QUESTION (B.3)

[1.0]

A room contains a source which, when exposed, results in a general area dose rate of 175 millirem per hour. This source is scheduled to be exposed continuously for 35 days. Select an acceptable method for controlling radiation exposure from the source within this room.

a.

Lock the room to prevent inadvertent entry into the room.

b.

Equip the room with a device to visually display the current dose rate within the room.

c.

Equip the room with a motion detector that will alarm in the control room.

d.

Post the area with the words "Danger-Radiation Area".

Section B Normal/Emerg. Procedures & Rad Con QUESTION (B.4)

[1.0]

Consider two point sources, each having the same curie strength. Source A's gammas have an energy of 1 MEV whereas Source B's gamma have an energy of 2 MEV. You obtain a reading from the same Geiger counter 10 feet from each source. Concerning the two readings, which one of the following statements is correct?

a.

Both readings are the same.

b.

The reading from Source B is half that of Source A.

c.

The reading from Source B is twice that of Source A.

d.

The reading from Source B is four times that of Source A.

QUESTION (B.5)

[1.0]

Which one of the following is the definition for Annual Limit on Intake (ALI)?

a.

10 CFR 20 derived limit, based on a Committed Effective Dose Equivalent of 5 rems whole body or 50 rems to any individual organ, for the amount of radioactive material inhaled or ingested in a year by an adult worker.

b.

The concentration of a radionuclide in air which, if inhaled by an adult worker for a year, results in a total effective dose equivalent of 100 millirem.

c.

The effluent concentration of a radionuclide in air which, if inhaled continuously over a year, would result in a total effective dose equivalent of 50 millirem for noble gases.

d.

Projected dose commitment values to individuals, that warrant protective action following a release of radioactive material.

QUESTION (B.6)

[1.0]

Which one of the following meets the MINIMUM staffing requirement when the reactor is NOT shutdown?

a.

1 SRO in the control room and 1 health physics on call.

b.

2 ROs in the control room, and the Radiation Protection Officer on call.

c.

1 SRO and the Radiation Protection Officer onsite, and 1 RO in the control room.

d.

2 licensed operators on site and 1 health physics on call.

QUESTION (B.7)

[1.0]

Which one of the following is NOT a reportable occurrence?

a.

An explosive device was found in the parking lot next to the containment.

b.

An automatic scram occurs due to failure of one of the period channels.

Section B Normal/Emerg. Procedures & Rad Con

c.

A review of the logs shows that the facility was left unattended for 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months with the console key inserted but in the off position.

d.

The on duty SRO walks in the control room, notices that the Hold-Down Grid Unlatched alarm is actuated, and he asks the console operator to scram the reactor.

QUESTION (B.8)

[1.0]

DELETED When responding to a High Level Radiation Monitor alarm, which one of the following readings from the Stack Area Monitor represents the minimum for notification of Unusual Event?

a.

6 mr/h

b.

70 kcpm

c.

30 mr/h

d.

150 kcpm QUESTION (B.9)

[1.0]

Assuming the following core conditions:

Reactor Power = 6.6 MW; Primary Flow = 2000 gpm; Core Tank Level = 8 ft.

Which one of the following is the minimum outlet temperature that exceeds the safety limit?

a.

71

b.

74

c.

77

d.

80 QUESTION (B.10)

[1.0]

Two senior reactor operators and a trainee are operating the reactor at night. One SRO has to go home for an emergency. They drive all the control rods in and shutdown the reactor. The shutdown checklist was not completed and one SRO remained in the control room at all times. The minimum Checklist(s) that must be completed for the next reactor startup, to full power, 3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months later is:

a.

Full-power checklists - PM 3.1.1.1, Two Loop Mechanical and PM 3.1.1.2.1, Two Loop Instrumentation - S/D <16 hours.

b.

PM 3.1.1.4., Two Loop Restart Incorporating Required Monthly Startup Surveillances

c.

PM 3.1.1.2., Two Loop Instrumentation

d.

PM 3.1.6, Restart Following an Unanticipated or Brief-duration Scheduled Shutdown.

Section B Normal/Emerg. Procedures & Rad Con QUESTION (B.11)

[1.0]

In the event of a significant Heavy Water spill, which one of the following actions should NOT be performed?

a.

Secure building ventilation.

b.

Scram the reactor.

c.

Stop pumps DM-1 and DM-2.

d.

Evacuate non-essential personnel and energize the Do Not Enter signs at both personnel airlocks.

QUESTION (B.12)

[1.0]

What action should be taken if the shim bank exceeds the estimated critical position (ECP) by more than 0.5 inches and the reactor has not reached criticality?

a.

Continue withdrawing rods until the reactor is critical and note new rod heights in log book.

b.

Immediately scram the reactor and follow the appropriate emergency procedure.

c.

Notify the SRO on duty and continue under careful scrutiny.

d.

Lower rods by 1 inch or more and determine the cause of the discrepancy.

QUESTION (B.13)

[1.0]

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

a.

Excess reactivity must be measured before full power is reached.

b.

The method of cooling tower flow must be switched to spray.

c.

Thermal equilibrium between the core and the coolant reduces stress on fuel cladding.

d.

Adjust the bucking voltage potentiometer.

Section B Normal/Emerg. Procedures & Rad Con QUESTION (B.14)

[1.0]

A safety function required by Technical Specifications as a Limiting Condition for Operation is to be temporarily bypassed (assume it is not a part of an approved procedure). Which one of the following statements is NOT a guideline to bypass the safety function as required by PM 1.9 "Bypass of Safety Functions and Jumper Control".

a.

Bypasses or jumpers may be installed for maintenance or testing purposes only when the reactor is shutdown.

b.

If Jumpers are used, the jumper must be tagged and a warning tag is to be placed on the shim blade control handle.

c.

Such bypasses must be approved by Duty-Shift-Supervisor or Reactor Superintendent

d.

If the reactor is to be operated with the bypass installed, a record of the authorizer's initial must be recorded on the bypass log.

QUESTION (B.15)

[1.0]

The for the MIT Research Reactor is taken to be a 100 meter zone that forms an annulus about the facilitys containment building.

Which one of the following terms fits in the blank?

a.

Restricted Area

b.

Site Boundary

c.

Emergency Planning Zone

d.

Operations Boundary QUESTION (B.16)

[1.0]

In the event of isolation of the air space above the core, which one of the following is the preferred response to such an occurrence?

a.

insert a minor scram.

b.

shutdown the reactor immediately.

c.

investigate the cause of the isolation and resume the continuous purge as soon as possible.

d.

immediately reduce reactor power to <100 kW.

Section B Normal/Emerg. Procedures & Rad Con QUESTION (B.17)

[1.0]

Which one of the following may be described as a Credible Accident Possibly Leading to an Off-Site Radiological Emergency at MIT?

a.

Loss of reactor shielding

b.

Blockage of fuel element channels

c.

Loss of coolant above the level of the anti-siphon valves.

d.

Occurrence of a severe storm, flood, or earthquake QUESTION (B.18)

[1.0]

Which one of the following statements is NOT a violation of Technical Specifications?

a.

Reactor power is 100 kW and emergency power is not available.

b.

Operating with one inoperable shim blade fully inserted.

c Reactor power is 2 MW, one primary pump is in service, and the coolant flow rate is 1000 gpm.

d.

Reactor power is 150 kW with the emergency cooling system inoperable.

QUESTION (B.19)

[1.0]

During continuous power operation with the automatic control system, it may be necessary for the operator to reshim the control blades to maintain the regulating rod within its useful range. Which one of the following describes a requirement associated with this reshim of the control blades?

a.

Reactor power must be maintained within 2.5% of the desired level while reshimming.

b.

All shim blades must be maintained within 2.5 inches of each other during the reshim and within 1.0 inch following the reshim.

c.

The last motion of any shim blade is in the outward direction by at least 0.1 inches.

d.

All the shim blades must first be raised by a small increment then lowered to within a few tenths of an inch of each other.

Section B Normal/Emerg. Procedures & Rad Con QUESTION (B.20)

[1.0]

A 15 ml sample of primary water is removed from the sample station. What is the dominant nuclide you would expect assuming routine (normal) operation?

a.

Na-24

b. U-235

c. Co-60

d. Ar-41

(*** End of Section B ***)

Section C Plant and Rad Monitoring Systems QUESTION (C.1)

[1.0]

Which one of the following describes decay heat removal capability while on Emergency Power?

a.

Primary coolant system auxiliary pump MM2 can be restarted after resetting the low-voltage protection.

b.

Primary coolant system pump MM1 can be restarted after resetting the low-voltage protection.

c.

Standby Transfer Pump DM-2 will automatically start on high temperature.

d.

Natural circulation provides cooling since pumping power is not available.

QUESTION (C.2)

[1.0]

Which ONE of the following is NOT a function of the primary cleanup system?

a.

Provide emergency core cooling spray.

b.

Maintain level with the core tank.

c.

Remove decay heat during reactor shutdown.

d.

Supply cooling for the lead thermal doors.

QUESTION (C.3)

[1.0]

Which one of the following is the correct type of detector used for Nuclear Instrumentation Channel 9 (used as input to the regulating rod automatic control circuit)?

a.

Fission Chamber

b.

Boron Lined Compensated Ion Chamber

c.

Boron Lined Uncompensated Ion Chamber

d.

Unlined Ion Chamber

Section C Plant and Rad Monitoring Systems QUESTION (C.4)

[1.0]

Which one of the following is correct with respect to maintaining the D2O reflector dump valve closed when air compressor CM-2 is tagged out for maintenance?

a.

As long as solenoid valves CV-90 and CV-91 remain as is, the dump valve will remain shut.

b.

A dedicated air receiver just upstream of CV-90 and CV-91, contains sufficient air volume to maintain the dump valve shut for eight hours.

c.

On a low pressure signal a solenoid valve will automatically shift the dump valve air supply to a bank of air cylinders.

d.

When air in the header decreases below 95 psig, a check valve will open supplying air from the backup air receiver.

QUESTION (C.5)

[2.0, 0.25 each]

Match the facility conditions in Column I with the type of response expected to occur from the Reactor Safety System in Column II. (Assume the reactor is critical.)

Items in Column I have only one correct answer and items in Column II may be used once, more than once or not at all.

Column I Column II (Condition)

(Response)

a.

Core tank level 2 inches

1. Alarm ONLY.

below overflow pipe.

2. Rod withdrawal inhibited.

b.

Shield coolant flow equals 55 gpm.

3. Scram.

c.

Reactor outlet temperature

4. No safety system response equals 50 °C.

d.

Reactor building vacuum equals 1.2 inches water above atmospheric.

e.

Primary cleanup system temperature equals 52 °C.

f.

D2O flow equals 88 gpm.

g.

Core Purge flow equals 2.0 cfm

h.

Secondary Water Monitor sample flow equals 1 gpm

Section C Plant and Rad Monitoring Systems QUESTION (C.6)

[1.0]

The operator accidentally depresses the ARI pushbutton. Which one of the following actions will stop the inward motion of the shim blades?

a.

Going to the out position on the regulating rod.

b.

Depressing the Alarm Acknowledge pushbutton.

c.

Depressing the Scram Reset pushbutton.

d.

Depressing the Reactor Start pushbutton QUESTION (C.7)

[1.0]

Why is blowdown of the cooling tower basins required by procedures to be secured whenever the reactor is shutdown?

a.

The secondary water monitors cannot detect leakage when the reactor is shutdown due to short-lived isotopes.

b.

Secondary system level cannot be adequately measured when shutdown due to thermal expansion during operation.

c.

Shutdown cooling system efficiency may be adversely affected due to blowdown.

d.

The cooling tower level detectors and automatic makeup system is not energized when the reactor is shutdown.

QUESTION (C.8)

[1.0]

If during an accident the Containment Building begins to approach its design pressure, what design feature provides for containment protection?

a.

A pressure relief blower automatically initiates at 2.0 psig.

b.

A containment relief valve will automatically open at 1.75 psig.

c.

A manually operated relief valve may be opened to protect containment.

d.

The main damper will cycle open and closed to maintain containment pressure less than 1.75 psig.

Section C Plant and Rad Monitoring Systems QUESTION (C.9)

[1.0]

The Plenum Air Effluent Monitor picks up radiation levels in excess of operating limits. Which one of the following actions will NOT occur immediately as a result?

a.

Intake Backup Damper will close

b.

Exhaust Fans will stop.

c.

Intake Butterfly Damper will close.

d.

Intake Fans will stop.

QUESTION (C.10)

[1.0]

Which one of the following statements is NOT a purpose of the D2O helium cover gas system?

a.

It prevents air with entrained H2O moisture from entering the system, coming in contact with and degrading the D2O.

b.

It prevents the corrosion that would be caused by nitrous-oxide formation from air in the presence of high radiation fields.

c.

It provides an oil-filled loop seal to minimize contamination of the D2O in the reflector tank.

d.

It provides an inert, non-radioactive vehicle to circulate the disassociated D2 and O2 from the reflector tank to the recombiner.

QUESTION (C.11)

[1.0]

The reactor is operating at full power with an experiment loaded in the pneumatic system. How long after receiving a "Vacuum Off Pneumatic System" alarm will the temperature in the pneumatic tubes reach 100 °C?

a.

30 seconds

b.

6 minutes

c.

45 minutes

d.

120 minutes

Section C Plant and Rad Monitoring Systems QUESTION (C.12)

[2.0, 0.66 each]

Match the location or feature from Column I with the gas from Column II which is used as a cover or operating fluid. Items in Column I have only one correct answer and items in Column II may be used once, more than once or not at all.

Column I Column II

a.

Graphite Reflector

1. Carbon Dioxide

b.

Lead shutter region gas box

2. Argon

c.

Vertical Thimbles

3. Air

4. Helium

5. Nitrogen QUESTION (C.13)

[1.0]

With a nominal battery load of 72 amps, the Emergency Power Distribution System batteries have the capacity to supply power to selected instruments and pumps for approximately ( ) following the loss of both external electrical power feeders.

a.

2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months

b.

4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months

c.

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months

d.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months QUESTION (C.14)

[1.0]

What automatic action occurs when a high radiation alarm is received on the Sewer Monitor?

Assume that the Sewer Monitor is in its normal mode of monitoring liquid radioactive waste being pumped from the sumps to the waste tanks.

a.

The Radioactive Liquid Waste System Containment Isolation valve closes.

b.

The Inlet City Water Solenoid valve closes.

c.

The Sump pumps trip.

d.

The on-line Sewer pump trips.

Section C Plant and Rad Monitoring Systems QUESTION (C.15)

[1.0]

At what core tank level would city water NOT be utilized for emergency core cooling?

a.

48 inches

b.

52 inches

c.

36 inches

d.

72 inches QUESTION (C.16)

[1.0]

Which one of the following is the method by which gamma-ray compensation is accomplished in the nuclear instrumentation compensated ion chamber?

Gamma-ray compensation is accomplished by:

a.

varying the pressure of the detector Argon charge gas in conjunction with a low boron concentration coating the inside walls of the outer chamber.

b.

the comparison of the currents generated in two concentric chambers in the detector, one sensitive only to gammas and one sensitive to neutrons and gammas.

c.

a pulse height discriminator that eliminates (or discriminates) the pulses from the low energy gammas and allows only the higher energy neutron signals through.

d.

varying the amount and concentration of the boron trifluoride gas in the compensated ion chamber thus reducing the detector's sensitivity to gamma induced ionizations.

QUESTION (C.17)

[1.0]

Rod withdrawal times are measured at least annually. The blade system must be adjusted if the time to withdraw a blade a distance of 8.5 inches is measured to be other than:

a.

5 minutes +/- 1%

b.

3 minutes +/- 10%

c.

2 minutes +/- 10%

d.

1 minute +/- 10%

Section C Plant and Rad Monitoring Systems QUESTION (C.18)

[1.0]

Which one of the following describes an automatic response of the ventilation system?

a.

If temperature of the air entering the building drops below approximately 35F the intake fan will stop.

b.

If the main intake damper fails to close within 3 seconds of a trip signal, then the intake fan will trip.

c.

If the auxiliary intake damper fails to close within 3 seconds of a trip signal, then the main damper will close.

d.

In the "weekend-open" position, if activity is detected by the plenum monitors, the inlet dampers and intake fan will trip.

(*** End of Section C ***)

Section A _ Theory, Thermo & Fac. Operating Characteristics ANSWER KEY A.1 b

REF:

Glasstone, S. and Sesonske, A, Nuclear Reactor Engineering, Kreiger Publishing, Malabar, Florida, 1991, § 5.47 A.2 b

REF:

Glasstone, S. and Sesonske, §§ 3.161 3.163 A.3 d

REF:

Glasstone, S. and Sesonske,§ 3.161 3.163 1/32 (1 - 0.95) = 1 - Keff2 --- 1 - 0.05/32 = Keff2 --- Keff2 = 0.9984 A.4 c

REF:

Glasstone, S. and Sesonske, § 5.55.

k = 1 / (1- ) k = 1 when =

A.5 b

REF:

Glasstone, S. and Sesonske, § 3.44 & § 5.9.

p=(k-1)/k; p= -0.05; -0.05k = k-1; 1 = k-(-0.05k) = k(1+0.05); k=1/1.05; k=0.9524 A.6 a

REF:

Glasstone, S. and Sesonske §§ 7.131 7.155.

A.7 c

REF:

SDM = (1-Keff)/Keff Keff = 1/(SDM + 1) = 1/(.0526 + 1) =.95 CR1/CR2 = (1 - Keff2) / (1 - Keff1) 10/20 = (1 - Keff2) / (1 - 0.95)

(0.5) x (0.05) = (1 - Keff2)

Keff2 = 1 - (0.5)(0.05) = 0.975 A.8 a

REF:

Glasstone, S. and Sesonske, § 5.98 A.9 a

REF:

Glasstone, S. and Sesonske, §§ 3.161 3.163 A.10 d

REF:

Glasstone, S. and Sesonske, §§ 2.70 2.74 A.11 b

REF:

T = (-)/

T = t/ln 2 = 24/.693 = 34.6 seconds 34.6 =.0070 - /0.1 x 3.46 =.007-/

(3.46+1)=.007

=.007/4.46 =.00157 =.16% K/K A.12 c

REF:

Glasstone, S. and Sesonske, 1991, § 10.34 A.14 d

REF:

Glasstone, S. and Sesonske, § 5.81 5.83

Section A _ Theory, Thermo & Fac. Operating Characteristics

Section A _ Theory, Thermo & Fac. Operating Characteristics A.15 c

REF:

DOE Fundamentals Handbook, Nuclear Physics and Reactor Theory Volume 2, Module 3, Enabling Objective 5.4 A.16 b

REF:

Pf = Po et/T = 5.5 MW e(1 sec/0.5 sec) = 40.6 MW A.18 c

REF:

RSM 6.4 A.19 c

REF:

Glasstone, S. and Sesonske, §§ 2.213 2.219 A.20 c

REF:

Glasstone, S. and Sesonske, §§ 5.56 5.80

Section B Normal/Emerg. Procedures & Rad Con B.1 b

REF:

AP 1.10.8.1.1(11)

B.2 c

REF:

DR1D1 2 = DR2D2 2

D2= 2000mr / 5mr = 20 feet B.3 a

REF:

10CFR20.1601(a)(3)

B.4 a

REF:

GM is not sensitive to energy.

B.5 a

REF:

10CFR20.1003 B.6 c

REF:

TS 7.1.3 B.7 b

REF:

TS definition 1.3.32 B.8 a

DELETED REF:

PM 5.6.2, Emergency Action Levels B.9 c

REF:

T.S. 2.1 (Safety Limits); PM 5.1.3 B.10 d

REF:

PM 2.2.1 B.11 a

REF:

PM 5.8.16, Spill of Heavy Water B.12 d

REF:

PM 2.3 B.13 c

REF:

PM 2.3.1 - Step 21 B.14 d

REF:

PM 1.9 pg. 1 of 2 B.15 c

REF:

Chapter 4 (E-Plan) PM 4.6 B.16 c

REF:

Tech. Spec. 3.3.2 B.17 b

REF:

Chapter 4 (E-Plan) PM 4.5 B.18 c

REF:

T.S. 3.6; T.S. 3.1.4.2; T.S. 2.2; T.S. 3.3.4

Section B Normal/Emerg. Procedures & Rad Con B.19 c

REF:

PM 2.4 B.20 a

REF:

RRPO surveys

Section C Facility and Radiation Monitoring Systems C.1 a

REF:

RSM-8.30; 8.8.2, Emergency Power Distribution System C.2 d

REF:

MITR-II Reactor Systems Manual § 3.2.3.

C.3 a

REF:

MITR-II Reactor Systems Manual § 5.6.3 C.4 d

REF:

MITR-II, Reactor Systems Manual, § 8.6.2 C.5 (a. 2) (b. 3) (c. 4) (d. 2) (e. 1) (f. 3)

(g. 1) (h. 1)

REF:

MIT RSM 9.9 & RSM 7.10 (7.5)

C.6 d

REF:

MITR-II, Reactor Systems Manual, § 4.4 C.7 a

REF:

RSM 7.4.1 C.8 c

REF:

RSM - 8.4 C.9 a

REF:

MITR-II, Training Program Sample Questions § C question 2 C.10 c

REF:

RSM-3.16 (3.7.1)

C.11 b

REF:

PM 5.5.1 C.12 (a. 1) (b. 1) (c. 1)

REF:

RSM 1.1, 2.9, 2.10 C.13 d

REF:

RSM - 8.35 C.14 c

REF:

RSM 7.7 and 8.24 C.15 d

REF:

RSM 3.2.7 C.16 b

REF:

RSM-5.2.2 C.17 c

REF:

MIT Question Bank Sect. B pg. 6 of 13 C.18 a

REF:

RSM Table 9.4.3

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