ML103230425
| ML103230425 | |
| Person / Time | |
|---|---|
| Site: | 05000128 (R-083) |
| Issue date: | 11/22/2010 |
| From: | Johnny Eads Research and Test Reactors Branch B |
| To: | Reece W Texas A&M Univ |
| Nguyen JT, DPR/PROB, 301-415-4007 | |
| Shared Package | |
| ML102290457 | List: |
| References | |
| 50-128/10-001, 50-128/11-001 | |
| Download: ML103230425 (31) | |
Text
November 22, 2010 Dr. Warren D. Reece, Director Texas A&M University System Nuclear Science Center 1095 Nuclear Science Road MS 3575 College Station, Texas 77843-3575
SUBJECT:
INITIAL EXAMINATION REPORT NO. 50-128/OL-11-01, TEXAS A&M UNIVERSITY
Dear Dr. Reece:
During the week of October 18, 2010, the U.S. Nuclear Regulatory Commission (NRC) administered operator licensing examinations at your Texas A&M University TRIGA 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 at the conclusion of the examination with those members of your staff identified in the enclosed report.
In accordance with Title 10, Section 2.390 of the Code of Federal Regulations, 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 Public Electronic Reading Room). The NRC is forwarding the individual grades to you in a separate letter which will not be released publicly. If you have any questions concerning this examination, please contact Mr. John T. Nguyen at (301) 415-4007 or via internet e-mail John.Nguyen@nrc.gov.
Sincerely,
/RA/
Johnny H. Eads, Jr., Chief Research and Test Reactors Oversight Branch Division of Policy and Rulemaking Office of Nuclear Reactor Regulation Docket No. 50-128
Enclosures:
- 1. Initial Examination Report No. 50-128/OL-11-01
- 2. Written Exam with facility comments incorporated cc: w/o enclosures: See next page
ML OFFICE PRTB:CE IOLB:LA E
PRTB:BC NAME JNguyen CRevelle JEads DATE 11/ 08/2010 11/ 19/2010 11/ 23/2010
Texas A&M University Docket No. 50-128 cc:
Mayor, City of College Station P.O. Box Drawer 9960 College Station, TX 77840-3575 Governors Budget and Planning Office P.O. Box 13561 Austin, TX 78711 Texas A&M University System ATTN: Jim Remlinger, Associate Director Nuclear Science Center Texas Engineering Experiment Station F. E. Box 89, M/S 3575 College Station, Texas 77843 Radiation Program Officer Bureau of Radiation Control Dept. Of State Health Services Division for Regulatory Services 1100 West 49th Street, MC 2828 Austin, TX 78756-3189 Susan M. Jablonski Technical Advisor Office of Permitting, Remediation & Registration Texas Commission on Environmental Quality P.O. Box 13087, MS 122 Austin, TX 78711-3087 Test, Research and Training Reactor Newsletter 202 Nuclear Sciences Center University of Florida Gainesville, FL 32611
U. S. NUCLEAR REGULATORY COMMISSION OPERATOR LICENSING INITIAL EXAMINATION REPORT REPORT NO.:
50-128/OL-10-01 FACILITY DOCKET NO.:
50-128 FACILITY LICENSE NO.:
R-83 FACILITY:
Texas A&M University TRIGA Reactor EXAMINATION DATES:
October 18, 2010 SUBMITTED BY:
__________/RA/______________
__11/9/2010______
John T. Nguyen, Chief Examiner Date
SUMMARY
During the week of October 18, 2010, the NRC administered operator licensing examinations to five Reactor Operator license candidates and two Senior Reactor Operator license candidates (one Upgrade and one Instant). Two Reactor Operator license candidates failed the written examination (one candidate failed section A and B and the other failed section B). All other license candidates passed all applicable portions of their examinations.
REPORT DETAILS
- 1.
Examiners:
John T. Nguyen, Chief Examiner, NRC
- 2.
Results:
RO PASS/FAIL SRO PASS/FAIL TOTAL PASS/FAIL Written 3/2 1/0 4/2 Operating Tests 5/0 2/0 7/0 Overall 3/2 2/0 5/2
- 3.
Exit Meeting:
John Nguyen, Chief Examiner, NRC Jerry Newhouse, Reactor Supervisor, Texas A&M University TRIGA Reactor The examiner thanked the facility for their support during the examination.
ENCLOSURE 2 TEXAS A&M UNIVERSITY TRIGA REACTOR Operator Licensing Examination Written Exam with Answer Key October 18, 2010
Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 1 QUESTION A.01
[1.0 point]
Shown below is a trace of reactor period as a function of time. Between points A and B reactor power is:
- a.
continually increasing.
- b.
continually decreasing.
- c.
increasing, then decreasing.
- d.
increasing, then constant.
QUESTION A.02 [1.0 point]
Which ONE of the following will be the resulting stable reactor period when a 0.312 %k/k reactivity is inserted into an exactly critical reactor core? Given = 0.007
- a.
12 seconds
- b.
24 seconds
- c.
38 seconds
- d.
50 seconds QUESTION A.03 [1.0 point]
Which ONE of the following parameters is MOST significant in determining the differential worth of a control rod?
- a.
Rod speed.
- b.
Flux Shape.
- c.
Fuel loading.
- d.
Reactor power.
Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 2 QUESTION A.04
[1.0 point]
With a 30 second period, power would double in approximately:
- a.
15 seconds
- b.
21 seconds
- c.
32 seconds
- d.
60 seconds QUESTION A.05 [1.0 point]
List from high to low by thermal neutron cross section of the following isotopes:
- 1. B-10
- 2. Sm-149
- 3. Xe-135
- 4. U-235
- a.
3,2,1,4
- b.
2,3,4,1
- c.
3,1,4,2
- d.
3,1,2,4 QUESTION A.06
[1 point]
Which ONE of the following materials is the best moderator for the reactor?
- a.
Water.
- b.
- c.
graphite.
- d.
Uranium-238.
Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 3 QUESTION A.07
[1.0 point]
Which ONE of the following is the MAJOR source of energy released during SHUTDOWN?
- a.
Prompt gamma rays.
- b.
Decay of the fission fragments.
- c.
Kinetic energy of the fission neutrons.
- d.
Kinetic energy of the fission fragments.
QUESTION A.08
[1.0 point]
Which ONE of the following is the correct amount of reactivity added if the multiplication factor, k, is increased from 0.800 to 0.950?
- a.
0.150
- b.
0.158
- c.
0.188
- d.
0.197 QUESTION A.09
[1.0 point]
Delayed neutrons are produced by:
- a.
decay of O-16.
- b.
Photoelectric Effect.
- c.
decay of fission fragments.
- d.
directly from the fission process.
Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 4 QUESTION A.10
[1.0 point]
Which ONE of the following conditions will INCREASE the shutdown margin of a reactor?
- a.
Lowering moderator temperature (Assume negative temperature coefficient).
- b.
Insertion of a positive reactivity worth experiment.
- c.
Burnout of a burnable poison.
- d.
Fuel depletion.
QUESTION A.11 [2.0 points, 0.5 each]
Match each of the terms in column A with the correct definition from column B.
Column A Column B
- a.
Fast neutrons
- 1. Neutrons released directly from fission.
- b.
Prompt neutrons
- 2. High energy neutrons.
- c.
Slow neutrons
- 3. Neutrons released from decay of fission products.
- d.
Delayed neutrons
- 4. Low energy neutrons.
Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 5 QUESTION A.12
[1.0 point]
The following data was obtained during a reactor fuel load.
No. of Elements Detector A (cps) 0 30 10 40 20 60 30 100 50 300 Which ONE of the following is the closest number of fuel elements required to make the reactor critical? (The attached figure may be used to determine the correct response.)
- a.
55
- b.
60
- c.
65
- d.
70 QUESTION A.13
[1.0 point]
Given the following worth:
excess = $0.90 SAFE
= $2.20 REG blade
= $0.30 SHIM
= $1.55 Calculate the TECHNICAL SPECIFICATION LIMIT of Shutdown Margin for this core.
- a.
$0.95
- b.
$1.25
- c.
$1.55
- d.
$3.15
Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 6 QUESTION A.14
[1.0 point]
In a just critical reactor, adding one dollar worth of reactivity will cause:
- a.
A sudden drop in neutron flux.
- b.
The reactor period to be equal to (-)/.
- c.
All prompt neutron term to become unimportant.
- d.
The resultant period to be a function of the prompt neutron lifetime.
QUESTION A.15
[1.0 point]
The probability of neutron interaction per cm of travel in a material is defined as:
- a.
a neutron flux.
- b.
a mean free path.
- c.
a microscopic cross section.
- d.
a macroscopic cross section.
QUESTION A.16
[1.0 point]
Which ONE of the following is NOT a correct statement regarding the production/depletion of Xenon in an operating reactor?
- a.
Xe-135 is lost by alpha decay.
- b.
Xe-135 is lost by neutron absorption.
- c.
Xe-135 is formed by fission and I-135 decay.
- d.
I-135 is formed by fission and lost by beta decay to Xe-135.
Section A - Reactor Theory, Thermohydraulics & Fac. Operating Characteristics Page 7 QUESTION A.17
[1.0 point]
The delayed neutron fraction,, is defined as a ratio of:
- a.
Thermal utilization over fast fission factor.
- b.
The number of thermal neutrons over the number of fast neutrons in the core.
- c.
The number of delayed neutrons over the number of total neutrons in the core.
- d.
The number of thermal neutrons absorbed in fuel over the number of thermal neutrons absorbed in core materials including in fuel.
QUESTION A.18
[1.0 point]
Following a scram, the value of the stable reactor period is:
- a.
approximately -10 seconds, as determined by the rate of decay of the shortest lived prompt neutrons.
- b.
approximately -80 seconds, as determined by the rate of decay of the shortest lived delayed neutron precursor.
- c.
approximately -80 seconds, as determined by the rate of decay of the longest lived delayed neutron precursors.
- d.
infinity because the control rods absorb all neutrons.
QUESTION A.19
[1.0 point]
INELASTIC SCATTERING is the process by which a neutron collides with a nucleus and Y
- a.
recoils with the same kinetic energy it had prior to the collision.
- b.
recoils with a lower kinetic energy than it had prior to the collision with the nucleus emitting a gamma ray.
- c.
is absorbed, with the nucleus emitting a gamma ray.
- d.
recoils with a higher kinetic energy than it had prior to the collision with the nucleus emitting a gamma ray.
- End of Section A ********************************
Section B - Normal/Emergency Procedures and Radiological Controls Page 8 QUESTION B.01
[1.0 point]
Which ONE of the following conditions is a violation of Technical Specifications?
- a.
The pH of the pool water is between 7.2 and 7.8.
- b.
The reactivity worth of an individual experiment is $1.60.
- c.
Steady state power level of 1.2 megawatts for purpose of calibration.
- d.
The excess reactivity is 5.6 % k/k (assume cold and xenon-free criticality).
QUESTION B.02
[1.0 point]
Which ONE of the following types of experiments shall NOT be irradiated at the NSC REACTOR?
- a.
The experiment contains iodine isotopes 131 through 135.
- b.
The in-pool experiment contains 25-milligram explosive materials.
- c.
The unsecured experiment has a reactivity worth of $0.75.
- d.
The total single experiment activity of Xe-124 is 1000 Ci.
QUESTION B.03
[1.0 point]
Which ONE of the following is the correct statement when the airborne activity in the NSC Control Access Area (CAA) exceeds the preset level of Xe-125 Air Monitor?
- a.
The ventilation system is MANUALLY secured and the reactor is permitted to operate a period of time not to exceed 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
- b.
The ventilation system is AUTOMATICALLY secured and the reactor is permitted to operate a period of time not to exceed 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.
- c.
The ventilation system is AUTOMATICALLY secured and the reactor is permitted to operate a period of time not to exceed 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
- d.
The ventilation system is AUTOMATICALLY secured and the reactor shall not be operated.
Section B - Normal/Emergency Procedures and Radiological Controls Page 9 QUESTION B.04
[1.0 point]
A radioactive source reads 160 Rem/hr on contact. Four hours later, the same source reads 40 Rem/hr. How long is the time for the source to decay from a reading of 160 Rem/hr to 10 Rem/hr?
- a.
6.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />
- b.
8.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />
- c.
9.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />
- d.
10.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> QUESTION B.05
[1.0 point]
An example of Byproduct Material would be.
- a.
- b.
- c.
- d.
Co-60 QUESTION B.06
[1.0 point]
Which ONE of the following is the appropriate Emergency Classification when the Xe-125 monitor alarms and indicates a release of 150 Ci from the reactor building?
- a.
Operational Events
- b.
Notification of Unusual Events
- c.
Alert
- d.
Site Area Emergency
Section B - Normal/Emergency Procedures and Radiological Controls Page 10 QUESTION B.07 [1.0 point]
Exposing a 2 mCi check source to the continuous air monitor (CAM) 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.
QUESTION B.08
[1.0 point]
The following measurements are made from a beta-gamma point source:
2 R/hr at six inches 0.5 mR/hr at ten feet.
What are the relative fractions of betas and gammas emitted at six inches?
- a.
(1800/200) = 9
- b.
(2000/200) = 10
- c.
(1800/20) = 90
- d.
(2200/200) = 11 QUESTION B.09
[1.0 point]
The concentration of Argon-41 in the effluent gas from the facility as diluted by atmospheric air in the lee of the facility due to the turbulent wake effect shall not exceed 1.0x 10-8 µCi/mI averaged over one year. This is an example of a:
- a.
safety limit.
- b.
limiting safety system setting.
- c.
limiting condition for operation.
- d.
surveillance requirement.
Section B - Normal/Emergency Procedures and Radiological Controls Page 11 QUESTION B.10
[1.0 point]
An area in which radiation levels could result in an individual receiving a dose equivalent in excess of 120 mRem/hr is defined as:
- a.
Radiation area.
- b.
Restricted Area.
- c.
- d.
Very High Radiation Area.
QUESTION B.11
[1.0 point]
Which ONE of the following is the NSC REACTOR Safety Limit?
- a.
Maximum pulse shall be limited to $2.00.
- b.
The power level shall not exceed 1.3 megawatts at steady state operation.
- c.
The temperature in a stainless-steel clad fuel element shall not exceed 830 °C under PULSE operation.
- d.
The temperature in a stainless-steel clad fuel element shall not exceed 1150 °C under any conditions of operation.
QUESTION B.12
[1.0 point]
Question deleted during administrative of the examination. No correct answer in the distractors. This question will not factor into the candidates grades Which ONE of the following is a MINIMUM number of staffing requirements for an OFFICIAL review and approval of an Experiment Authorization (EA)?
- a.
Deputy Director TEES (Licensee) only.
- b.
NSC Director and the RSO staff.
- c.
The operations staff, the RSO staff, and a member from the NRC.
- d.
The operations staff, the RSO staff, and a member from Deputy Director TEES.
Section B - Normal/Emergency Procedures and Radiological Controls Page 12 QUESTION B.13
[1.0 point]
The radiation from an unshielded Co-60 source is 500 mrem/hr. What thickness of lead shielding will be needed to lower the radiation level to 5 mrem/hr? The HVL (half-value-layer) for lead is 6.5 mm.
- a.
26 mm.
- b.
33 mm.
- c.
38 mm.
- d.
44 mm.
QUESTION B.14
[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.
QUESTION B.15 [2 points, 0.5 each]
Match the 10CFR55 requirements for maintaining an active operator license in column A with the corresponding time period from column B. Items in column B can be used once, more than once or not at all.
Column A Column B
- a.
Renew License 1 year
- b.
Medical Exam 2 years
- c.
Pass Requalification Written Examination 4 years
- d.
Pass Requalification Operating Test 6 years
Section B - Normal/Emergency Procedures and Radiological Controls Page 13 QUESTION B.16
[1.0 point]
Which ONE of the following is considered a damaged fuel?
- a.
In measuring the transverse bend, its lateral bending exceeds 0.120 inches over the length of the cladding.
- b.
In measuring the elongation, its length exceeds its original length by 0.25 inches.
- c.
A reactivity worth of fuel element is $0.02 less than the previous measure.
- d.
Color of a fuel clad changes to brown.
QUESTION B.17 [2 points, 0.5 each]
Match each of the measuring channels in column A with the reactor modes for which it must be operable in column B. Items in column B can be used once, more than once or not at all.
Column A Column B
- a.
Fuel Temperature
- 1. Steady State ONLY
- b.
Linear Power Level
- 2. Pulse ONLY
- c.
Preset Timer
- 3. All Modes
- d.
Log Power Level
- 4. During Reactor Startup QUESTION B.18
[1.0 point]
As permitted by 10 CFR 50.59, the NSC reactor facility may:
- a.
Modify systems and change the Technical Specifications (TS) if the NRC is notified afterwards.
- b.
Perform a reactor calibration without a notification to the NRC.
- c.
Determine the affects of modifications and their impact on TS.
- d.
Redefine the boundaries of accidents previously analyzed in the Safety Analysis Report (SAR).
- End of Section B ********************************
Section C: Plant and Rad Monitoring Systems Page 14 QUESTION C.01
[1.0 point]
Given the following sequence of events during the course of pulsing:
(1) The reactor is in steady state at a power of 100 watts (2) Power is applied to the pulse integrator (3) The mode selector switch is switched to the pulse mode (4) A preset time sets 3 seconds Reactor operator initiates a pulse by pressing the fire button. Which ONE of the following sequences of events takes place?
- a.
The transient rod air will be energized then de-energized in 1 second and the transient rod will drop back into the core.
- b.
The transient rod air will be energized then de-energized in 3 second and the transient rod will drop back into the core.
- c.
The transient rod air will be de-energized, rod will drop back into the core, and the reactor scram.
- d.
The transient rod air will be energized then de-energized in 1 second, rod will drop back into the core, and the integrator displays the total energy.
QUESTION C.02
[1.0 point]
What is the purpose of the exhaust duct in the lower irradiation cell?
- a.
To minimize buildup of water if a leak develops in the irradiation window.
- b.
To minimize radiation exposure due to production of Ar-41.
- c.
To minimize radiation exposure due to production of N-16.
- d.
To reduce humidity for experiment efficiency.
QUESTION C.03
[1.0 point]
Graphite inserts are placed in the top and bottom of the fuel element. Which ONE of the following best describes the function of these inserts?
- a.
To absorb thermal neutrons.
- b.
To reduce neutron leakage.
- c.
To absorb fission product gases.
- d.
To increase fast neutron flux.
Section C: Plant and Rad Monitoring Systems Page 15 QUESTION C.04
[1.0 point]
Which ONE of the following actions will cause the operating reactor to automatically SCRAM?
- a.
Opening the thermal column shield door with the reactor positioned at the centerline of BP 1 & 4.
- b.
Opening one of the beam port lead seal doors when the reactor is in the stall core position.
- c.
Opening the cave door to BP4 when the reactor is against the radiography reflector.
- d.
Opening the irradiation cell door when the reactor is in the pool core position.
QUESTION C.05
[1.0 point]
What is the maximum acceptable time between the initiation of a scram signal, and the time that the SHIM rod is fully inserted in the core?
- a.
2.5 sec
- b.
2.0 sec
- c.
1.2 sec
- d.
1.0 sec QUESTION C.06
[1.0 point]
The output of 1kW interlock signal comes from:
- a.
Wide Range Linear Monitor
- b.
Log Power Channel Monitor
- c.
Safety Channel 1 Power Monitor
- d.
Safety Channel 2 Power Monitor
Section C: Plant and Rad Monitoring Systems Page 16 QUESTION C.07
[2.0 points, 0.25 each]
Match the input signals listed in column A with their display on reactor control room listed in column B. (Items in column B may be used more than once or not at all). Assume that the reactor is in operation.
Column A Column B
- a.
Bridge unlocked.
- 1. Indication only
- b.
3-sec period.
- 2. Alarm only
- c.
110% Safety Power channel.
- 3. Alarm and scram
- d.
Building pressure system failure.
- 4. Alarm and interlock QUESTION C.08
[1.0 point] Transient was added during the administrative of the examination Which ONE of the following can cause the Transient control rod interlock when a steady state mode is selected?
- a.
SHIM rod drive DOWN and SHIM control rod DOWN.
- b.
Carriage DOWN and supply air energized.
- c.
SHIM rod drive UP and SHIM control rod DOWN.
- d.
Carriage UP and supply air energized.
QUESTION C.09
[1.0 point]
If the Power Channel output is higher than the calculated thermal power calibration (calorimetric), the reactor operator needs to adjust the Power Channel output by:
- a.
adjusting the detector high voltage.
- b.
adjusting the Full Power Gain potentiometer gain.
- c.
physically adjusting the height of the detectors in the support assembly.
- d.
move graphite reflector to change the neutron flux near the detectors.
Section C: Plant and Rad Monitoring Systems Page 17 QUESTION C.10
[1.0 point]
For calibration of the control rod, the operator calculates the reactor period by measuring the time required for the power to double or power to triple. This technique is called:
- a.
Rod Drop Method
- b.
Positive Period Method
- c.
Negative Period Method
- d.
Thermal Power Calibration Method QUESTION C.11
[1.0 point]
Which ONE of the following will result in a reactor scram?
- a.
Log power < 2 cps
- b.
Conductivity of the bulk Water = 5 X 106 ohms/cm
- c.
Initiation of a pulse at 2 kW steady state power
- d.
Failure of the power supply for a safety chamber QUESTION C.12
[1.0 point]
Which ONE of the following elements is used as the neutron absorber in the Shim-Safety rods?
- a.
- b.
Borated Graphite
- c.
- d.
Section C: Plant and Rad Monitoring Systems Page 18 QUESTION C.13
[1.0 point]
Which ONE of the following air monitor channels is designated as the Fission Product Monitor?
- a.
Facility Air Monitor Channel 1
- b.
Facility Air Monitor Channel 2
- c.
Facility Air Monitor Channel 3
- d.
Facility Air Monitor Channel 4 QUESTION C.14
[1.0 point]
The primary isotope we worry when standing by the reactor pool surface at high power is
- a.
- b.
Kr80 (Kr79 (n, ) kr80).
- c.
Ar41 (Ar40 (n, ) Ar41).
- d.
H2 (H1 (n, ) H2).
QUESTION C.15
[1.0 point]
Which ONE of the following statements is NOT TRUE regarding the Servo Flux Control system?
- a.
Pressing the Gang-Up/Gang-Down switch will turn off the servo unit.
- b.
The regulating rod moves in response to the signal from compensated ion chamber.
- c.
The regulating rod moves in response to the signal from fission chamber.
- d.
Alarm if the REG rod is inserted less than 20% fully withdrawn.
Section C: Plant and Rad Monitoring Systems Page 19 QUESTION C.16
[1.0 point]
Which ONE of the following is the main function of the demineralizer in the primary purification system?
- a.
Remove soluble impurity to maintain low conductivity in the tank water.
- b.
Reduce N-16 formation, thus reduce the dose rate at the reactor pool.
- c.
Absorb thermal neutrons, thus increase life of the reactor pool.
- d.
Absorb tritium, thus maintain purity of the pool water.
QUESTION C.17
[1.0 point]
During a pulse channel calibration, reactor operator switches the reactor selector to PULSE mode, then he depresses and holds the Pulse Cal switch and fire the transient rod. The pulse integrator will display a reading of
- a.
100%
- b.
1.0 MW
- c.
55.5 MW-sec
- d.
1999 MW QUESTION C.18
[1.0 point]
During reactor operation, a leak develops in the primary to secondary heat exchanger. Which one of the following conditions correctly describes how the system will react?
- a.
Pool level will increase due to leakage from the secondary, the automatic level control will maintain level in the secondary.
- b.
Cooling tower basin level will decrease due to leakage from the secondary, pool level will increase.
- c.
Cooling tower level will increase due to leakage from the primary, automatic level control will maintain level in the primary.
- d.
Cooling tower basin level will increase due to leakage from the primary, pool level will decrease.
Section C: Plant and Rad Monitoring Systems Page 20 QUESTION C.19
[1.0 point]
What prevents a fuel followed control rod from falling out of the core should it become detached from its mounting?
- a.
Bottom of pool is within 2 inches of grid plate.
- b.
Notch in control rod pole connected to reactor frame.
- c.
Safety plate assembly beneath the reactor grid plate.
- d.
Tapered section above absorber prevents passage through reactor frame.
- End of Section C *****************************
- End of the Exam ***************************
Section A L Theory, Thermo & Facility Operating Characteristics Page 21 A.01 d
REF:
Standard NRC question. From point A to near point B, reactor period is positive, and since Pf=Po*e T t
, power will continue to increase. At point B, reactor period reaches to infinitive, e initive t
inf
= e0
=1, so Pf=Po. Power is stable at point B.
A.02 a
REF:
Glasstone, S. and Sesonske, A, Nuclear Reactor Engineering, 1991, § 5.18, p. 234.
T = (-)/
T = (.007 -.00312)/.1 x.00312 = 12 seconds A.03 b
REF:
Fund. Of Nuclear Engineering, Chapter 3, Section 4, page 75.
A.04 b
REF:
P=Poet/ or t/T= ln (P/Po). t=30*ln(2); t= 21 sec A.05 a
REF Introduction to Nuclear Operation, Reed Burn, 1988, Table 2.5, page 2-59 A.06 a
REF NRC Standard Question A.07 b
REF Introduction to Nuclear Operation, Reed Burn, 1988, Sec 3.2, page 3-5 A.08 d
REF:
Burn, R., Introduction to Nuclear Reactor Operations, © 1982, Sec 3.3.3, page 3-21.
In order to solve the question A.08, the applicant can use one of the following methods:
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
= 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)
A.09 c
REF:
Burn, R., Introduction to Nuclear Reactor Operations, © 1982, Sec 3.2.
A.10 d
REF Standard NRC question A.11 a, 2; b, 1; c, 4; d, 3 REF:
FONRE, 24 & 25, pp. 27 & 28
Section A L Theory, Thermo & Facility Operating Characteristics Page 22 A.12 b
REF:
Burn, R., Introduction to Nuclear Reactor Operations, © 1982, § 5.5, pp. 5-18 5-25.
No.
fuel A(cps) 1/M (Source/Count) 0 30 1
10 40 0.75 20 60 0.5 30 100 0.3 50 300 0.1 A.13 a
REF:
Total rod worth - (excess + most active rod)
$(2.20 +1.55+0.30) -$(0.90+2.20) =$0.95 A.14 d
REF Introduction to Nuclear Operation, Reed Burn, 1988, Sec 4.2, page 4-4 A.15 d
REF:
Burn, R., Introduction to Nuclear Reactor Operations, © 1982, Section 2.5.2, page 2-44.
A.16 a
REF:
Burn, R., Introduction to Nuclear Reactor Operations, Sec 8.2, page 8-3.
A.17 c
REF Introduction to Nuclear Operation, Reed Burn, 1988, Sec 3.3.3, page 3-11.
A.18 c
REF Introduction to Nuclear Operation, Reed Burn, 1988, Sec 4.5, page 4-12 A.19 b
REF:
FONRE, ' 18.e.3.a(1), p. 10
Section B Normal, Emergency and Radiological Control Procedures Page 23 B.01 d
REF:
REF:
TS 3.6 B.03 d
REF:
TS 3.5 B.04 b
REF:
DR = DR*e -t 40 rem/hr = 160 rem/hr* e -(4hr)
Ln(40/160) = -*4 --> =0.347; solve for t: Ln(10/160)=-0.347 *t t=8 hours B.05 d
REF:
10 CFR 20.1003 B.06 b
REF:
EP Table I, page 19 B.07 a
REF:
TS 1.0, Definition B.08 a
REF:
Assume beta will not travel 10 feet in air, therefore 0.5 mr is gamma.
Gamma dose at 1/2 ft (6 in) is: (DR1)(R12) = (DR2)(R22) DR2 = (DR1)(R12) / R22 =
0.5 mr x (10 ft)2 / (0.5 ft)2 = 200 mr/hr Therefore, beta contribution at 1/2 ft is 2000 - 200 = 1800 mr/hr.
Beta contribution/Gamma contribution = 1800/200 = 9 B.09 c
REF:
TS 3.5.2 B.10 c
REF:
10 CFR 20 B.11 d
REF:
TSs 2.0 and 3.0 B.12 d Question deleted during administrative of the examination. No correct answer in the distractors. This question will not factor into the candidates grades REF:
Procedure F,Section I, page 2 of 3 B.13 d
REF:
DR = DR*e -X HVL ( =6.5 mm) means the original intensity will reduce by half when a lead sheet of 6.5 mm is inserted. Find if the HVL is given as follows: 1 = 2* e -*6.5 ;
= 0.10664 Find X: 5 mrem/hr = 500 mrem/hr* e -0.10664*X ; X= 43.2 mm B.14 b
Section B Normal, Emergency and Radiological Control Procedures Page 24 REF:
NRC standard question B.15 a (6 ) b(2 )
c(2) d(1)
REF:
10 CFR 55.55(a)
B.16 b
REF:
TS 4.4 B.17 a (3 ) b(1 )
c(2) d(1) or d(3) Answer key added during the administrative of the examination.
REF:
TS 3.2.1 B.18 c
REF:
10 CFR 50.59
Section C Facility and Radiation Monitoring Systems Page 25 C.01 b
REF:
SOP III, Procedure F C.02 b
REF:
SOP IV-E-1 C.03 b
REF Basic TRIGA fuel design C.04 c
REF:
SOP IV-F-3 C.05 c
REF:
TS 3.2.3 C.06 b
REF:
SAR, 7.2.3.1 Log Power Channel C.07 a(2) a(3) b(3) c(1) d(2)
Answer changed during the administrative of the examination.
REF:
TS 3.3 and SAR 7.0, Instrumentation and Control C.08 d
REF:
SAR, 7.3 Reactor Control Systems C.09 b
REF:
SOP II, Procedure J C.10 b
REF:
SOP II, Procedure K C.11 d
REF:
TS 3.0 C.12 b
REF:
TS 5.3 C.13 b
REF:
SOP VII, Procedure B12 C.14 a
REF NRC Standard Question C.15 c
REF:
SAR, 7.1 Summary Description, Figure 7-1 C.16 a
REF:
NRC Standard Question C.17 c
Section C Facility and Radiation Monitoring Systems Page 26 REF:
SOP II, Procedure L C.18 d
REF SAR IV-B.2 and figure 4-6.
C.19 c
REF SAR, 4.2.5 Core Support Structure