Text

Missouri University of Science and Technology, No. 50-123/OL-10-01, Initial Examination Report
	ML093270549
Person / Time
Site:	University of Missouri-Rolla
Issue date:	12/01/2009
From:	Johnny Eads; Research and Test Reactors Branch B
To:	Frimpong S; Missouri Univ of Science & Technology
	Nguyen JT, DPR/PRTB, 301-415-4007
References
	50-123/10-001
	Download: ML093270549 (27)
	v • d • e

December 1, 2009 Dr. Samuel Frimpong, Chair Mining and Nuclear Engineering 226 McNutt Hall Missouri University of Science and Technology Rolla, MO 65409-0450

SUBJECT:

INITIAL EXAMINATION REPORT NO. 50-123/OL-10-01, MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY

Dear Dr. Frimpong:

During the week of November 2, 2009, the NRC administered an operator licensing examination at your Missouri University of Science and Technology Reactor. The examination was conducted according to NUREG-1478, "Operator Licensing Examiner Standards for Research and Test Reactors," Revision 2. 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 (PARS) component of NRC's Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html. The NRC is forwarding the individual grades to you in a separate letter which will not be released publicly. Should you have any questions concerning this examination, please contact Mr. John T. Nguyen at 301-415-4007 or via internet e-mail at John.Nguyen@nrc.gov.

Sincerely,

/RA TBlount for/

Johnny H. Eads, Jr., Chief Research and Test Reactors Branch B Division of Policy and Rulemaking Office of Nuclear Reactor Regulation Docket No. 50-123

Enclosures:

1. Initial Examination Report No. 50-123/OL-10-01

2. Written examination with facility comments cc without enclosures: see next page

December 1, 2009 Dr. Samuel Frimpong, Chair Mining and Nuclear Engineering 226 McNutt Hall Missouri University of Science and Technology Rolla, MO 65409-0450

SUBJECT:

INITIAL EXAMINATION REPORT NO. 50-123/OL-10-01, MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY

Dear Dr. Frimpong:

During the week of November 2, 2009, the NRC administered an operator licensing examination at your Missouri University of Science and Technology Reactor. The examination was conducted according to NUREG-1478, "Operator Licensing Examiner Standards for Research and Test Reactors," Revision 2. 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 (PARS) component of NRC's Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html. The NRC is forwarding the individual grades to you in a separate letter which will not be released publicly. Should you have any questions concerning this examination, please contact Mr. John T. Nguyen at 301-415-4007 or via internet e-mail at John.Nguyen@nrc.gov.

Sincerely,

/RA TBlount for/

Johnny H. Eads, Jr., Chief Research and Test Reactors Branch B Division of Policy and Rulemaking Office of Nuclear Reactor Regulation Docket No. 50-123

Enclosures:

1. Initial Examination Report No. 50-123/OL-10-01

2. Written examination with facility comments cc without enclosures:

Please see next page DISTRIBUTION w/ encls.:

PUBLIC PRTB r/f RidsNRRDPRPRTA RidsNRRDPRPRTB Facility File (CRevelle) O-07 F-08 ADAMS ACCESSION #: ML093270549 TEMPLATE #:NRR-074 OFFICE PRTB:CE IOLB:LA E

PRTB:BC NAME JNguyen jtn CRevelle car JEads jhe DATE 11/23/09 11/30/09 12/1/09 OFFICIAL RECORD COPY

University of Missouri - Rolla Docket No. 50-123 cc:

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

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

50-123/OL-10-01 FACILITY DOCKET NO.:

50-123 FACILITY LICENSE NO.:

R-79 FACILITY:

Missouri University of Science and Technology EXAMINATION DATES:

November 2-4, 2009 SUBMITTED BY:

______/RA/

11/23/09 John T. Nguyen, Chief Examiner Date

SUMMARY

During the week of November 2, 2009, the NRC administered operator licensing examinations to one Senior Reactor Operator - Instant (SRO-I) and two Reactor Operator (RO) applicants.

The RO applicants passed all portions of the examinations. The SRO-I applicant failed Section B of the written examination.

REPORT DETAILS

1.

Examiner:

John Nguyen, Chief Examiner, NRC

2.

Results:

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

3.

Exit Meeting:

John Nguyen, NRC, Examiner Bill Bonzer, Reactor Supervisor, Missouri University of Science and Technology The examiner thanked the facility for their cooperation during the examination. No generic issues were identified.

ENCLOSURE 1

License Operator Written Examination With ANSWER KEY OL-10-01 MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY November 02, 2009 ENCLOSURE 2

FACILITY COMMENT Question A.07 The answer key lists d, 0.197. This answer is correct with the equation used in the reference,

= k1-k2/(k1 x k2) ; = 0.95-0.80/(0.95 x 0.80) = 0.197. In the equation sheet supplied with the written exam the equation = k1-k2/(k1 x k2) was not listed. = Keff/Keff was listed and using as (0.95-0.80)/0.95 = 0.1579. This answer is basically answer b.

I request that question A7 have two correct answers b and d.

NRC Response Facility comment is NOT accepted.

The listed equation, = Keff/Keff, is derived from = Keff-1/Keff or the definition of reactivity, not. In order to solve the question A.07, the applicant can use one of the following methods:

a) At k=0.8; = Keff/Keff or = Keff-1/Keff = -0.2/0.8 =-0.25. At k=0.95, =-0.05/0.95

= -0.053. The difference between is the answer,i.e. -0.053-(-0.25)=0.197 b) = 1 - 2 where 1 = Keff1-1/Keff1 and 2 = Keff2-1/Keff2. Substitute 1 and 2 with Keff1 and Keff2 into the equation above, the result is = keff1-keff2/(keff1 x keff2)

FACILITY COMMENT Question C.01 In Question C1 - Match the input signals listed in column A with their respective responses listed in column B.

Step g Radiation monitor at reactor top indicates 20 mRem/hr has (4) indication and scram as the correct answer in the answer key.

The RAM system (radiation monitor at reactor top) does not have scram trips. They do have rundown trips that occur around 15 mRem/hr. The TS require a rundown to occur by 30 mRem/hr.

I request to eliminate step g from the examination.

NRC Response Facility comment accepted. Step g listed in question C.01 is deleted and will not factor into the candidates grades. In the future, the question will be modified accordingly.

FACILITY COMMENT Question C.13 The answer key lists a a channel test as the correct answer. I believe a typo has occurred and answer b a channel check was meant to be the correct answer listed. The definitions for channel test and check are the following:

Channel check - a qualitative verification of acceptable performance by observation of channel behavior or by comparison of the channel with other independent channels or systems measuring the same variable.

Channel test - the introduction of a signal into the channel to verify that it is operable.

Exposing a check source to the particulate detector is a qualitative verification of acceptable performance by observation of channel behavior and not the introduction of a signal into the channel.

I request that answer b channel check be listed as the correct answer for question C13.

NRC Response Facility comment accepted. Answer key changed from a to b per facility comment. Corrected typographical error.

Section A L Theory, Thermo & Facility Operating Characteristics Page 1 QUESTION A.01

[1.0 points]

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

a.

Fast fission factor.

b.

Reproduction factor.

c.

Thermal utilization factor.

d.

Resonance escape probability.

Answer:

QUESTION A.02

[1.0 point]

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

a.

250 kW

b.

600 kW

c.

900 kW

d.

2200 kW Answer:

A.2 d

REF:

Section A L Theory, Thermo & Facility Operating Characteristics Page 2 QUESTION A.03

[1 points]

Which ONE of the following best describes the alpha decay of a nuclide?

a.

The atomic mass number increases by 2, and the number of protons increase by 2.

b.

The atomic mass number decreases by 2, and the number of protons decrease by 2.

c.

The atomic mass number decreases by 4, and the number of protons decrease by 2.

d.

The atomic mass number increases by 4, and the number of protons increase by 2.

Answer:

A.03 c

REF:

Chart of the Nuclides QUESTION A.04

[1.0 point]

During a reactor startup, criticality occurred at a LOWER ROD HEIGHT than the last startup.

Which ONE of the following reasons could be the cause?

a.

Xe135 peaked.

b.

Fuel temperature decreased.

c.

Moderator temperature increased.

d.

Adding an experiment with negative reactivity.

Answer:

A.04 b

REF:

QUESTION A.05

[1.0 point]

About two minutes following a reactor scram, the reactor period has stabilized and the power level is decreasing at a CONSTANT rate. Given that reactor power at time t0 is 100 kW power, what will it be three minutes later?

a.

2 kW.

b.

10 kW.

c.

30 kW.

d.

50 kW.

Answer:

A.5 b

REF: P = P0 e-T/J = 100 kW H e(180sec/-80sec) = 100 kW H e-2.25 = 0.1054 H 100 kW = 10 kW

Section A L Theory, Thermo & Facility Operating Characteristics Page 3 QUESTION A.06

[1.0 point ]

The RESONANCE ESCAPE PROBABILITY is defined as a ratio of:

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

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

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

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

Answer:

A.06 d

QUESTION A.07

[1.0 point]

Facility comment is NOT accepted Which ONE of the following is the correct amount of reactivity added if the multiplication factor, k, is increase from 0.800 to 0.950?

a.

0.150.

b.

0.158.

c.

0.188.

d.

0.197.

Answer:

A.7 d

= k1-k2/(k1 x k2) ; = 0.95-0.80/(0.95 x 0.80) =0.197

Section A L Theory, Thermo & Facility Operating Characteristics Page 4 QUESTION A.08

[1.0 point]

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

a.

A measure of the core's fuel depletion.

b.

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

c.

The factional change in neutron population between generations.

d.

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

Answer:

A.08 c

QUESTION A.09

[1.0 point]

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

a.

660.

b.

750.

c.

850.

d.

1170.

Answer:

A.09 a

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

Count1*(1-0.9208) = Count2*(1-0.948)

Count1*(1-0.9208) = 1000(1-0.948); Count 1 = 657 cps

Section A L Theory, Thermo & Facility Operating Characteristics Page 5 QUESTION A.10

[1.0 point]

Most text books list for a U235 fueled reactor as 0.0065. However, your SAR lists eff as being 0.0079. Why is eff larger than ?

a.

The fuel includes U238 which has a relatively large for fast fission.

b.

Some U238 in the core becomes Pu239 (by neutron absorption) which has a larger for fission.

c.

Delayed neutrons are born at lower energies than prompt neutrons resulting in a less loss due to leakage for these neutrons.

d.

Delayed neutrons are born at higher energies than prompt neutrons resulting in a greater worth for these neutrons.

Answer:

A.010 c

[1.0 point]

The neutron microscopic cross-section for absorption a generally

a.

increases as neutron energy increases.

b.

decreases as neutron energy increases.

c.

increases as target nucleus mass increases.

d.

decreases as target nucleus mass increases.

Answer:

A.011 b

REF:

Section A L Theory, Thermo & Facility Operating Characteristics Page 6 QUESTION A.12

[1.0 point]

Which ONE of the following ranges in the Safety rod position provides the HIGHEST worth during operation?

a.

From 1.0 to 5.0 in.

b.

From 10 to 14 in.

c.

From 14 to 18 in.

d.

From 20 to 24 in.

Answer: A.12 b

REF MSTR Worth Curve (note: center of safety rod provides the highest worth)

QUESTION A.13

[1.0 point]

Given the following:

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

a.

0.15% k/k

b.

0.65% k/k

c.

1.25% k/k

d.

1.75% k/k Answer: A.013 a

REF:

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

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

Section A L Theory, Thermo & Facility Operating Characteristics Page 7 QUESTION A.14

[1.0 point]

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

a.

subcritical.

b.

exactly critical.

c.

supercritical.

d.

prompt critical.

Answer: A.14 c

REF:

For prompt critical, keff has to be 1.0065 QUESTION A.15

[1.0 point]

Which ONE of the following describes the term PROMPT DROP?

a.

A reactor is subcritical at negative 80-second period.

b.

A reactor has attained criticality on prompt neutrons alone.

c.

The instantaneous change in power level due to inserting a control rod.

d.

The instantaneous change in power level due to withdrawing a control rod.

Answer: A.015 c

Section A L Theory, Thermo & Facility Operating Characteristics Page 8 QUESTION A.16

[1.0 point]

The MAXIMUM excess reactivity for reference core conditions with secured experiments and experimental facilities in place shall be no more than _____% k/k:

a.

1.00

b.

1.50

c.

2.00

d.

3.50 Answer: A.16 b

REF TS 3.1, page 7

- - - - End of Section A ********************************

Section B Normal, Emergency and Radiological Control Procedures Page 9 QUESTION B.01

[1.0 points]

Which ONE of the following types of experiments shall NOT be irradiated at MSTR?

a.

The secured experiments have a worth of - 1.00 % k/k.

b.

Experiments containing 15 milligrams of explosive materials.

c.

Fueled experiments in the amount which generates a power of 50 watts.

d.

Experiments having moving parts have a continuous insertion rate of 0.01 % k/k per second.

Answer: B.01 c

REF:

Technical Specifications § 3.7 QUESTION B.02

[1.0 points, 0.25 each]

Match the type of radiation in column A with their quality factor in column B. Items in column B is to be used once, more than once or not at all.

Column A Column B

a.

Beta

1.

1

b.

Gamma

2.

5

c.

Alpha particles

3.

10

d.

Neutrons of unknown energy

4.

20 Answer: B.02 a(1) b(1) c(4) d(3)

REF 10 CFR 20 QUESTION B.03

[1.0 point]

A radioactive source reads 35 Rem/hr on contact. Five hours later, the same source reads 1.5 Rem/hr.

How long is the time for the source to decay from a reading of 35 Rem/hr to 100 mRem/hr?

a.

6.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months .

b.

7.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months .

c.

8.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months .

d.

9.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months .

Answer: B.03 d

REF DR = DR*e -t 1.5 rem/hr =35 rem/hr* e -(5hr)

Ln(1.5/35) = -*5 --> =0.623; solve for t: Ln(.1/35)=-0.623 *t t=9.4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months

Section B Normal, Emergency and Radiological Control Procedures Page 10 QUESTION B.04

[1.0 points]

Given that the following emergency conditions occur at the MST reactor facility:

(a) Low level of coolant alarms (b) Particulate monitor alarms (c) Radiation levels at the site boundary indicate 100 mRem for one hour.

Which ONE of the following is the appropriate Emergency Classification?

a.

Notification of Unusual Event.

b.

Alert.

c.

Site Area Emergency.

d.

General Emergency.

Answer: B.04 c

REF Emergency Plan, Table 1, page 10 QUESTION B.05

[1.0 point]

A radioactive material is DECAYING at a rate of 30% per hour. Determine its half-life?

a.

1.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months .

b.

2.0 hours0 days 0 hours 0 weeks 0 months .

c.

2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months .

d.

3.0 hours0 days 0 hours 0 weeks 0 months .

Answer: B.05 b

REF DR = DR*e -t 30% is decayed, so 70% is still there 70% =100%* e -(1hr)

Ln(70/100) = -*1 -->=0.356 t1/2=Ln(2)/ -->.693/.356 t=1.94 hours0.00109 days 0.0261 hours 1.554233e-4 weeks 3.5767e-5 months

Section B Normal, Emergency and Radiological Control Procedures Page 11 QUESTION B.06

[1.0 point]

During a reactor startup, the reactor operator calculates that the maximum excess reactivity for reference core conditions is 1.6 % k/k. For this excess reactivity, which ONE of the following is the best action?

a.

Continue to operate because the excess reactivity is within TS limit.

b.

Increase power to 200 kW to verify the minimum excess reactivity.

c.

Shutdown the reactor; immediately report the result to NRC due to excess being above TS limit.

d Continue operation, but immediately report the result to the supervisor since the excess reactivity is exceeding TS limit.

Answer: B.06 c

REF TS 3.1 and 6.7.2 QUESTION B.07

[1.0 point]

An area in which radiation levels could result in an individual receiving a dose equivalent in excess of 100 mRem/hr is defined as:

a.

Radiation area.

b.

Unrestricted Area.

c.

High Radiation Area.

d.

Very High Radiation Area.

Answer: B.07 c

REF 10 CFR 20 QUESTION B.08

[1.0 point]

The reactor scrams during normal operations. The cause of the scram is reactor period. What is the minimum level of management who may authorize restart of the reactor under this condition?

a.

The Senior Operator on his/her own.

b.

The Senior Operator on consultation with either the Reactor Manager or the Reactor Director.

c.

The Reactor Manager after consultation with the Reactor Director.

d.

The Reactor Director only.

Answer: B.08 b

REF TS 6.6.2

Section B Normal, Emergency and Radiological Control Procedures Page 12 QUESTION B.09

[1.0 point]

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

a.

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

b.

1 RO on call, 1 RO in the control room, and 1 staff member.

c.

1 SRO on call, 1 RO in the control room, and 1 staff member.

d.

1 SRO on call, 1 reactor manager in the control room, and 1 staff member.

Answer: B.09 c

REF TS 6.1.3 QUESTION B.10

[1.0 point]

Which ONE of the following materials shall be doubly encapsulated at MSTR?

a.

A volatile material.

b.

A corrosive material.

c.

An explosive material.

d.

A short half-life material.

Answer: B.10 b

REF TS 3.7.2, page 16 QUESTION B.11

[1.0 point]

Which one of the following is the definition of Total Effective Dose Equivalent (TEDE) as specified in 10 CFR Part 20?

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.

Answer: B.11 c

REF 10 CFR 20.1003.

Section B Normal, Emergency and Radiological Control Procedures Page 13 QUESTION B.12

[1.0 point]

Select the list that gives the order of types of radiation from the LEAST penetrating to the MOST penetrating (i.e. travels the further in air).

a.

neutron, gamma, beta, alpha.

b.

alpha, beta, neutron, gamma.

c.

beta, alpha, gamma, neutron.

d.

alpha, neutron, beta, gamma.

Answer: A.12 b

REF NRC standard question QUESTION B.13

[1.0 point]

Per the Emergency Plan, If an emergency situation requires personnel to search for and remove injured person(s) or entry is necessary to prevent conditions that would probably injure numbers of people, a planned emergency exposure to the whole body could be allowed up to ____ to save a life.

a.

25 rem

b.

50 rem

c.

75 rem

d.

100 rem Answer:

B.013 c

REF:

Emergency Plan § 7.4.6, page 18.

QUESTION B.14

[1.0 point]

The MSTR reactor operator, who receives the total effective dose equivalent (TEDE) of 5.0 Rems, shall be

a.

placed under medical observation.

b.

restricted from any further radiation work.

c.

allowed to continue working until exceeding of 50 Rems.

d.

restricted from any further radiation work and placed under medical observation.

Answer: B.14 b

REF Emergency Plan, Section 7.4.6, page 19

Section B Normal, Emergency and Radiological Control Procedures Page 14 QUESTION B.15

[1.0 point]

The scramable time of a scramable control rod drop shall be measured:

a.

monthly.

b.

quarterly.

c.

semi-annually.

d.

annually.

Answer: B.15 c

REF TS 4.2.1 QUESTION B.16

[1.0 point]

A two curie source, with a 1.8 Mev gamma, is to be stored in the reactor building. How far from the source should a HIGH RADIATION AREA sign be posted?

a.

4 feet.

b.

15 feet.

c.

22 feet.

d.

66 feet.

B.16 b

REF 6CEN = R/hr @ 1 ft. -> 6 x 2 x 1.8 x 1 = 21.6 R/hr at 1ft. I0D0 2 = I*D2 -> 21.6 R/hr*1 ft

= 0.1 R/hr *D 2 D= (21.6/0.1) = 14.7 ft.

- - - - End of Section B ********************************

Section C - Facility and Radiation Monitoring Systems Page 15 QUESTION C.01

[2.0 points, 0.25 each]

Part g is deleted per facility comment.

This part will not factor into the candidates grades.

Match the input signals listed in column A with their respective responses listed in column B.

(Items in column B is to be used more than once or not at all.)

Column A Column B

a.

30-sec period.

1. Indication only.

b.

Bridge motion.

2. Indication and rod prohibit.

c.

Recorder off.

3. Indication and run down.

d.

Low CIC voltage.

4. Indication and scram.

e.

Log count rate = 1 cps.

f.

110 % full power.

g.

Radiation monitor at reactor top indicates 20 mRem/hr.

h.

Regulating rod insert limit on automatic.

Answer: C.01 a(2) b(4) c(2) d(3) e(2) f(1) g(4) h(3)

REF TS 3.2.1 and SAR Table 7.2 QUESTION C.02

[1.0 point]

A neutron flux will activate isotopes in air. This is the reason that N2 gas is used to drive the rabbit into and out of the core. The primary isotope we worry about in irradiating air is

a.

N16 (O16 (n,p) N16).

b.

C14 (C13 (n, ) C14).

c.

Ar41 (Ar40 (n, ) Ar41).

d.

H2 (H1 (n, ) H2).

Answer: C.02 c

REF NRC Standard Question

Section C - Facility and Radiation Monitoring Systems Page 16 QUESTION C.03

[1.0 point]

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

a.

Coating with U-235.

b.

A longer length tube, so target is larger for all incident events.

c.

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

d.

Any incident radiation event causing primary ionization results in ionization of entire detector.

Answer:

C.03 d REF Standard NRC question QUESTION C.04

[1.0 point]

Which ONE of the following represents the normal flow rate for the purification system?

a.

10 gpm.

b.

20 gpm.

c.

30 gpm.

d.

40 gpm.

Answer:

C.04 c

REF SAR 5.2 QUESTION C.05

[1.0 point]

The MSTR is licensed to receive, possess and use

a.

up to 5.5 kg of U-235 enriched to less than 20 % in the form of reactor fuel.

b.

up to 5.5 kg of U-235 enriched to less than 30 % in the form of reactor fuel.

c.

up to 10 kg of U-235 enriched to less than 20 % in the form of reactor fuel.

d.

up to 10 kg of U-235 enriched to less than 30 % in the form of reactor fuel.

Answer: C.05 a

REF SAR 9.5

Section C - Facility and Radiation Monitoring Systems Page 17 QUESTION C.06

[1.0 point]

Which ONE of the following conditions does not allow the reactor operator to change the reactor operation from a steady-state mode to an AUTOMATIC mode?

a.

One of shim rods is fully up.

b.

One of shim rods is fully down.

c.

The regulating rod position indicates 6 inches of withdrawal.

d.

The demand power sets at 125 kW, and the actual power indicates at 100 kW.

Answer:

C.006 d REF:

SAR 7.2.2.6 page 7-8, the servo system interlock (>2% of set point)

QUESTION C.07

[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.

Log & Linear Power Channel.

1. Monitor radiation level in the reactor top.

b.

Safety Channel.

2. Detect radioisotopes released due to fuel failure.

c.

Servo Amplifier System.

3. Protect the demineralizer resins.

d.

Portable monitor.

4. Survey of laboratory.

e.

Start up Channel.

5. Monitor neutron level during the reactor startup.

f.

Area radiation monitor.

6. Provide a period scram.

g.

Core Inlet Temperature.

7. Provide a high power level scram.

h.

Particulate monitor.

8. Permit reactor power to be automatically controlled during steady state operations.

Answer:

C.07 a(6) b(7) c(8) d(4) e(5) f(1) g(3) h(2)

REF TS 3.2

Section C - Facility and Radiation Monitoring Systems Page 18 QUESTION C.08

[1.0 point]

Which ONE of the following events provides the Maximum Hypothetical Accident (MHA) for the MSTR?

a.

Step reactivity insertion.

b.

Loss of primary coolant.

c.

Failure of a fuel experiment.

d.

Mishandling or malfunction of fuel.

Answer:

C.08 c

REF SAR Chapter 13 QUESTION C.09

[1.0 point]

Which ONE of the following is the method used to determine the control rod worths at MSTR?

a.

Rod Drop.

b.

Negative Period.

c.

Positive Period.

d.

Thermal Power calibration.

Answer:

C.09 a

REF SOP 109 QUESTION C.10

[1.0 point]

Which ONE of the following is the actual design feature which prevents siphoning of pool water on a failure of the purification system?

a.

A valve upstream of the primary pump will shut automatically.

b.

A valve downstream of the primary pump will shut automatically.

c.

The Emergency Fill system will automatically maintain pool level.

d.

Vacuum breaks are located in the system which prevents draining the pool below about 16 feet above the core.

Answer:

C.010 d REF:

SOP 309 Response to a Coolant System Leak

Section C - Facility and Radiation Monitoring Systems Page 19 QUESTION C.11

[1.0 point]

Per MSTR Technical Specifications, the minimum resistivity of the MSTR pool water shall be greater than ______ megohm-cm when the fuel elements are in the reactor pool.

a.

0.2

b.

0.5

c.

2.0

d.

5.0 Answer

C.11 a

REF TS 3.3 QUESTION C.12

[1.0 point]

Which ONE of the following describes the operation of the building ventilation system exhaust duct and intake louvers?

a.

The louvers automatically close when the ventilation fans are turned off.

b.

The louvers automatically close when the building evacuation alarm sounds.

c.

The louvers automatically close when any radiation area monitor alarms.

d.

When the louvers reach their fully-closed position, the ventilation fans automatically turn off.

Answer:

C.012 a REF:

SAR 9.1.

Section C - Facility and Radiation Monitoring Systems Page 20 QUESTION C.13

[1.0 point]

Exposing a check source to the particulate detector to verify whether it is operable is considered to be:

a.

a channel test.

b.

a channel check.

c.

a channel calibration.

d.

a channel verification.

Answer:

C.13 a b Key answer changed per facility comment. Corrected typographical error.

REF TS, Definition QUESTION C.14

[1.0 point]

What is the minimum level of management who may authorize removing or installing reactor thermocouples?

a.

SRO on call.

b.

SRO on duty.

c.

Reactor Manager.

d.

Reactor Director.

Answer: C.14 b

REF SOP 806

Section C - Facility and Radiation Monitoring Systems Page 21 QUESTION C.15

[1.0 point]

Which ONE of the following is the Limiting Safety System Settings (LSSS) for the MSTR?

a.

The cladding temperature must not exceed 510 °C.

b.

The cladding temperature must not exceed 527 °C.

c.

The thermal power shall not exceed 240 kW (120% of full power).

d.

The thermal power shall not exceed 300 kW (150% of full power).

Answer:

C.15 d

REF TS 2.2

- - - - End of Section C *****************************

- - - - End of the Exam ***************************

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