ML20207C915

Exam Rept 50-243/OL-86-02 on 861112-13.Exam Results:One Reactor Operator Candidate Passed Written & Oral Exams

ML20207C915
Person / Time
Site:	Oregon State University
Issue date:	12/08/1986
From:	Elin J, Johnston G NRC
To:
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ML20207C890	List: ML20207C887 ML20207C915
References
50-243-OL-86-02, 50-243-OL-86-2, NUDOCS 8612300279
Download: ML20207C915 (36)

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{{#Wiki_filter:. _ _ e 2 Examination Report No. 50-243/0L-86-02 Facility: Oregon State University TRIGA Reactor Docket No.:- 50-243 Examinations administered at Oregon State University Radiation Center, Corvallis, Oregon. / I Chief Examiners Gary W'.'Johnston Date Signed Operator Licensing Examiner s v / ~1 7 f(h i Approved: .Joh 0.- Elin, Chief Dat$S{gned Op ations Section Summary: ,e Examination on November 12-13, 1986. Written and oral examinations were administered to one RO candidate. The candidate passed the written and oral examinations. i 8612300279 86;;n;, PDR ADOCK 05000P43 PDrt

T, .L REPORT DETAILS '1.' Examiner: IG.W.Johnston 2. Persons attending the Exit Meeting: P. Morrill, NRC G.' Johnston,' NRC -S._Binney,.0SU ~ T. Anderson, OSU : B. Dodds, OSU 3. Written Examination and Facility Review: ^

The written examination was administered as follows

1ERO Exam - November 12, 1986: All sections. At the conclusion of the examination, the facility staff reviewed ^ the exsmination. Based on this review, the facility staff had, comments which were discussed and preliminary resolutions were proposed. Based on these discussions and a later follow-up letter of comments revisions were made to the key by the Chief Exaniner prior to grading the candidate responses. 4. Operating Excmination: _An oral examination and facility walkthrough was administered to the RO candidate. 5. Exit Meeting: On November 13, 1986, the examiners met with the licensee representatives listed in paragraph 3, above. The examiner advised the representative that no generic weakness was observed. The examiner also discussed the grading process for the written examination and the schedule.

s RESOLUTION OF FACILITY COMMENTS Facility Comment: B.3 !'The answer to Part.1 is not correct. The serial numbers on our fuel elements are on the top of each element, not on the botton." . Resolution: ), Agreed.- Key ~will be changed. Facilf t'- Comment: B.6 "We do not have a fuel element storage room." r " Resolution: Agreed. - Key will be changed. Facility Comment: B.7 "The answer to Part e is not complete. The transient rod is clad in aluminum. The other three control rods are clad in stainless steel as stated." . Resolution: The examiner vill allow the answer only if the transient rod is specified. Facility Comment: D.2 "This question can be legitimately be answered in other ways as it does not specifically ask for the circuitry involved." Resolution: The examiner agrees with the statement and will accept an answer that clearly is in context. 1

i Facility Comment: D.3 "The term PROTECTION as related to instrumentation is not one which is typically used at this' facility. Therefore, its use may be confusing to our operator candidate taking the exam. Again, with respect to terminology, we normally talk about the 1 kW pulse inhibit and the low source count interlock as coming from the log-N channel,.and the period scram as coming from the period channel. However, we recognize that the period channel in. turn comes form the log-N." Resolution: The examiner recognizes the terminology problem, however, it does appear to be somewhat moot as the question clearly elicits those features whether the terms are the same or not. The key will be corrected. Facility Comment: D.4 - "Our comment on Part a of this question is the same as that for D.2. It is not clear from the question that the answer the examiner wants is the circuitry of the control rod position indicators. Part b of this question is a little confusing and perhaps incomplete. There is not one CONT /0N light, but two. The CONT light is on when the magnet and control rod have made contact, and the ON lights on when power is supplied to the magnet." Resolution: The examiner agrees that this is confusing and should be clearer. However, the question does ask "How is control rod position determined?". The examiner will allow 1/2 credit for a description of the indicator . location, this should allow for the possibilities inherent in the question. Facility Consent: D.5 "The answer to Part e is not correct. The period channel signal comes from the fission chamber and not from an uncompensated ion chamber." Resolution: Agreed. Will change key.

3, /, s e / FacilipyComment:,F.1 "In. addition to.our Technical Specification limit of $2.55 for pulsing, we have an administrative limit of $2.50." Resolution: The examiner agrees and will accept either as correct. Facility Comments. F.7'. '"After we. initially provided the examiner with the required pre-exam information, the power calibration procedure was changed and is now performed at 1 MW. A copy of the new procedure was given to the examiner at the end of day." Resolution: -The examiner accepted the new information and on review elected to change the key for Part a to 1 MW.. Facility Comment: F.9 "It is acknowledged in Regulatory Guide 2.6 (Emergency Response Planning for Research and Test Reactors) that Class III and Class IV emergencies are not credible for research reactors of less than 2 MW power. For this reason, these classes of emergencies are not addressed in our emergency response plan or in the examinees training." Resolution: "The examiner agrees and will drop the Parts d and a from the exam key along with their points (1.0). Facility Comment: G.1 "For distances greater than six inches away from a cource, it is more appropriate (and still conservative) to use the Beta Factor /2 to determine the beta dose rate from the beta response of a Cutie Pie. This is explained in more detail on pages 36 and 37 in Volume 5 of the OSTR Training Manual." Resolution The examiner reviewed the material and will accept the 1/2 of the beta factor as answer.

{9,.,_., ) s S I k ? U.S. NUCLEAR REGULATORY COMMISSION l REACIOR OPERATl* LICENSE EXAMINATION i t Facility: Oregon scace Universicy f Reactor Type: Triga Date Administered: November 12, 1986 Examiner: Gary W. Johnston [ Candidate: be'hol M99 i INSTRUCTIONS TO CANDIDATE r i Use separate paper for t.he answers. Writa answers on one side only. Staple question sheet on top of the answer sheets. Points for each. question are indi-cated in parentheses after the question. The passing grade requires at least t 70% in each category. Examination papers will be picked up six (6) hours after I-the examination starts. Category % of Candidate's % of Value Total Score Cat. Value i f: 13.5 13.5 A. Principles of Reactor Operation 13.5 13.5 8. Features of Facility Design I 14.5 14.5 C. General Operating Characteristics E 13.5 13.5 D. Instruments and Controls 15.0 15.0 E. Safety and Emergency Systems 15.5 15.5 F. Standard and Emergency Operating Procedures 14.5 14.5 G. Radiation Control and Safety 100.0 [ Final Grade II ' l All work done on this exam is my own. I have neither given nor received aid. a:t f l Candidate's Signature l F i l .a-. t

l?h k,, ~~~ t ES-201-2 t{i t ATTACHMENT 2 REQUIREMENTS FOR ADMINISTRATION 0F WRITTEN EXAMINATIONS 1. A single room shall be provided for completing the written examina-tion. The location of this room and supporting restroom facilities shall be such as to prevent contact with all other facility and/or A contractor personnel during the duration of the written examination. F If necessary, the facility should make arrangements for the use of [ a suitable room at a local school, motel, or other building. Ob-taining this room is the responsibility of the licensee. t 2. Minimum spacing is required to ensure examination integrity as determined by the chief examiner. Minimum spacing should be one candidate per table, with a 3-ft space between tables. No wall charts, models, and/or other training materials shal.1 be present in r the examination room. 3. Suitable arrangements shall be made by the facility if the candi-dates are to have lunch, coffee, or other refreshments. These arrangements shall comply with Item 1 above. These arrangements shall be reviend by the examiner and/or proctor. t [ 4. The facility traff shall be provided a copy of the written examination and answer' key after the last candidate has completed and handed in his written examination. The facility staff shall then have five working t J days to provide formal written comments with supporting documentation on the examination and answer key to the chief examiner or to the regional office section chief. 5. The licensee shall provide pads of 8-1/2 by 11 in. lined paper in i unopened packages for each candidate's use in completing the exam-ination. The examiner shall distribute t.hese pads to the candidates. All reference material needed to complete the examination shall be furnished by the examiner. Candidates can bring pens calculators, or slide rules into the examination room,, pencils, and no other eq'ulpment or reference material shall be allowed. i 6. Only black ink or dark pencils should be used for writing answers' ' i to questions, i, p it i, l1 Examiner Standards 11 of 18 1,

ES-201-2 I I e NRC RULES AND GUIDELINES FOR LICENSE EXAMINATIONS e k During the administration of this examination the following rules apply: 1. Cheating on the examination means an gutomatic denial of your application and cou'd result in more severe penalties. t I 2. Restroom trips are to be limited and only one candidate at a time may L leave. You must avoid all contacts with anyone outside the examination room to avoid even the appearance or possibility of cheating. J. t; 3. Use black ink or dark pencil only to facilitate legible reproductions. 4. Print your name in the blank provided on the cover sheet of the examination. 5. Fill in the date on the cover sheet of the examination (if necessary). 6. Use only the paper provided for answers. L e, 7. Print your name in the upper right-hand corner of the first page of each section of the answer sheet. l 8. Consecutively number each answer sheet, write "End of Category " as appropriate, start each category on a new page, write only one sTde of the paper, and write "Last Page" on the last answer sheet. ~ 9. Number each answer as to category and number, for example,1.4, 6.3.

10. Skip at least three lines between each answer.

11. Separate answer sheets from down on your desk or table. pad and place finished answer sheets face

12. Use abbreviations only if they are commonly used in facility _ literature.

13. The point value for each question is indicated in parentheses after the question and can be used as a guide for the depth of answer required.

14. Show all calculations, methods, or assumptions used to obtain an answer lt to mathematical problems whether indicated in the question or not. l h 15. Partial credit may be given. Therefore, ANSWER ALL PARTS OF THE QUESTION AMD 00 NOT LEAVE ANY ANSWER BLANK. l 16. If parts of the examination are not clear as to intent, ask questions of the examiner only, i

17. You must sign the statement on the cover sheet that indicates that the j

work is your own and you have not received or been given assistance in completing the examination. This must be done after the examination has 7 been completed. l i 1 l Examiner Standards 12 of 18 \\ w-L

= -.- ES-201-2p

18. When you complete your examination, you shall:

g a. Assemble your examination as follows: (1) Exam questions on top. ii (2) ~ Exam aids'- figures, tables, etc. 3 { (3) Answer pages including figures which are a part of the answer. I b. Turn in your copy of the examination and all pages used to answer j the examination questions. s Turn in all scrap paper and the balance of the paper that you did c. j not use for answering the questions. t 4 d. Leave the examination area, as defined by the examiner. If after a leaving, you are found in this area while the examination is still in progress, your license may be denied or revoked. l f li t r l 7 ) s ?! Examiner Standards 13 of 18 I

d' s EQUATION SHEET p l w = ms a = v,t + hac Cycle efficiency = Net Work (out) 2 Energy (in) E = mc a = (vg - v,)/t EE = hev v A = AN g = y, + et A = A,e PE = agh a = e/t A = In 2/tg = 0.693/tg 5 W = v&P t (aff) = (e )(c ) g u g AE = 931Am (t +t) b Q = M AT I. I.-Ix r p k=UAAT I. I."WX Pwr = W E I - I,10'* g f SUR(t) P=P 10 TVL = 1.3/u o /T HVL=0.693[u t y.y o SUR = 26.06/T T = 1.44 DT SCR = S/(1 - K,gg) /A*reh p SUR = 26 g,, CR, = S/(1 - K,gg ) T=IL*/p)+ [(i

• p)/A,gg ]
• ff I ~
• ffb

~ o y, g*j (,, g M = 1/(1 - K,gg) = CR /CR g 0 7 = (I - p)/ A p eff M = (1 - K,gg) /(t. g.gf) 8 " ( eff-1)/K,gg = AK,gg/Keff SDM = (1 - K,gg)/K,gg [L*/TK,*gg.} + [B/(1 + A,gg )] L* = 1 x 10 seconds 9* T P = I(V/(3 x 1010) A,gg = 0.1 seconds ~I I=W Idgg=Id22 WATER PARAMETERS Id =Id g 2 2 1 gal. = 8.345 lba R/hr = (0.5 CE)/d (,,g,,,) i 1 gal. - 3.78 liters R/hr = 6 CE/d (feet) - I 1 fc3 = 7.48 gal. HISCEI.I.ANEOUS CONVERSIONS f Density = 62.4 lbm/fc 1 Curia = 3.7 x 1010 3 dpa i Density = 1 as/cm,3 1 kg = 2.21 lbm Heat of valorization'= 970 Itu/lba 1 hp = 2.54 x 103 BTU /hr Heat of fusica = 144 Btu /lba 1 MW = 3.41 x 100 Beu/hr 1 Atm = 14.7 psi - 29.9 in, l'g. 1 Btu = 778 ft-lbf k 2 i ft. H O = 0.4333 lbf/in 1 inch = 2.54 cm 2 F = 9/5 C + 32 'c = 5/9 (*r - 32)

> {;. n Section A Principles of Reactor Operation f F [

• QUESTION A.1'

( How much reactivity has been added to a suberitical reactor if F the count rate has increased from 100 cps to 150 cps and if the initial value of Koff was.957 (2.0)

1. ANSWER cr1 /cr2 (1-Keff2) / (1-Keff1)

CO.53 = 100/150 = (1-Keff2) / (1-0.95) 1-Keff2 = 10/15 x 0.05 Keff2 = 0.967 C0.53 change in reactivity = C1-Keff2/Keff23 - C1-Keff1/Keff13 = Keff2 - Keffi / Keff1 x Keff2 CO.53 = 0.967 - 0.95 / 0.95 x 0.967 = 1.85 */. delta K/K CO.53

1. REFERENCE Foster and Wright
2. QUESTION A.2 Assume you need a heat flux at full power of 100,000 Stus/hr. (sq. f t. ).

a '. In which heat transf er region in attched Figure A.04 should-the reactor operate? (0.5) f

b. Which region should be avoided?

(0.5) r

c. Explain your answers to a.

and b. (1.0)

1. ANSWER

a. Nucleate Boiling, or region II.

(0.5)

b. Film Boiling or region IV.

(0.5) c. It is important to stay in the Nucleate Boiling Region to limit fuel clad temperatures, which are much higher in the Film Boiling Region. (1.0) t

• REFERENCE l

General Atomic Training Material i 1 r

rc_r n:c: _ 2 ,___._.,.,_,___y_............,q ~ .e 3~ I IE I E I H Sill 6(E PffA5Et I m wmg l PARnAL._ l Fl1.H

• g.

CoNoEtt1oM I l Nu% l i!OtuMG l i 1 1 I I wo'.. ~ I I ll4N) ~ [ is I ( l I d-1 I I l I I I. I ~ l i 1 I i e ~ l I i ~ l I l i 1 I i 1 I I I d l I l l lo IM I 00 g AT between the cladding and the coolant FIG. A.,9 variation of heat flux with surface liquid temp. differences in a boiling system W

e 3 j.

• QUESTION A.3 3

What are delayed neutrons and why are they important in reactors t cooled and moderated by light water? { (2.0) {

• ANSWER f

Delayed neutrons are born some time after the fission event rather than directly from fission. C1.03 They are important because they greatly increase the average neutron lifetime and i enable stable control of the reactor. C1.03 i (2.0) +

• REFERENCE Slasstone and Sessonske I
• QUESTION A.4 Following a scram there is an initial prompt drop in power level f ollowed by a power decrease and a negative period.

What is the l value of this period and why is it always the same? (1.0)

• ANSWER e

-80 seconds.CO.53 Power cannot decrease faster than mean life f, time of longest lived precursor.CO.53 (This is 1.44 x 55 see 1/2 life of Br) (1.0) I }

• REFERENCE

[ Glasstone and Sessonske (

• QUESTION A.5 Describe the difference (s) between a fertile and a fissile

+ m,aterial. Give one example of each. [ (2'0) L

1. ANSWER L

Fissile Material will fission with neutrons of all energies. E (1.0) Example U235, U233, or Pu239 (1 at 0.5) Fertiles (Material has a fission neutron energy requirement well l above the thermal range.) After capturing a neutron, it may decay to a fissile material. Example U238, Th232 (1 at 0.5) (1.0)

• REFERENCE I

Glasstone and Seasonske f f t a i

h

1. QUESTION A.6 1

Give two (2) choices of materials that would be suitable for each f of the following purposes in a thermal reactors [ a. Moderator (1.0) i i b. Control rod poison (1.0) t i f

• ANSWER a.

carbon, hydrogenous material (water, poly, plastic, etc.), i beryllium b. boron, cadmium, hafnium k (2 answers each for a - c at 0.5 each)

• REFERENCE Foster and Wright, Basic Nuclear Engineering, Appx A l
• QUESTION A.7 GIVE three (3) factors that may cause critical rod position to change on the Osu Triga reactor.

(1.5)

• ANSWER

1. Power history (Xenon).

2. Temperature.

3. Experiments in the reactor.

4. Fuel burnup.

5. Rod location.

~

6. Fuel location.

Any 3 (0.5) each.

1. REFERENCE Stephenson, R.

1950. ' Introduction to Nuclear Engineering', 2nd Ed., McGraw Hill Book Company.

• QUESTION A.S Immediately after reactor shutdown, will decay heat and count rate exactly track down with each other? EXPLAIN.

(1.0) 1 c }

1. ANSWER g

No. (0.5) The neutron count rate will drop off fasteel it depends 4 on the number of fissions, while the decay heat rate depends on { the energy release from decay of fission products. (0.5).

1. REFERENCE Stephenson, R.

1958. ' Introduction to Nuclear Engineering', 2nd Ed., McGraw Hill Book Company. End of Section A Go on to Section B

o a ) 't g Section B f Features of Facility Design I t i

• QUESTION B.1 Draw a simple schematic of the Reactor Tank Cooling System (just the primary loop).

Show major components, direction of flow, g instrumentation, etc. (2.5)

• ANSWER See attached figure 1.60 r
• REFERENCE Figure 1.60, OSU Triga Manual
• QUESTION B.2 What is the primary reason that orbium was added to F' LIP fuel elements?

(1.5)

• ANSWER a.

To act as burnable poison, so that more fuel could be added for excess reactivity. (Provide longer life) (0.75) b. To provide the large MTC which otherwise would not be present in FLIP fuel. (0.75)

• REFERENCE Volume 3, OSU Triga Manual
• QUESTION B.3 Answer the following about reactor fuel rods:

p

1. How are individual fuel rods identifiable ?

(1.0)

2. How have the fuel rods been designed to minimize neutron leak-age at the top and bottom of the core and improve flux within the individual fuel rod 7

) (1.0)

• ANSWER T.p

)

1. Serial numbers on bo44em and fitting.

(1.0)

2. Oraphite slugs on either and act as top and bottom refloctors.

l (1.0)

• REFERENCE Volume 1, OSU Triga Manual i

J )'*

r' o I

• QUESTION B.4 I

State the purpose of the core diffuser system and explain how the P purpose is accomplished. (2.0) 't-p

• ANSWER g

The purpose is to reduce radiation Invels at the pool surface. k C1.03 A circuit from the Reactor Tank Cooling System discharges through a nozzle above the core and causes a circulation pattern which reduces surface done rate from N-16 gammas. C1.03 r o (2.0)

• REFERENCE Volume 1, OSU Triga Maual
• QUESTION B.5 Describe the material used in the followers attached to the four types of control rods and state the purpose pf each specific type follower.

(2.0)

• ANSWER Transient rod.

Air follower to minimize peaking. (0.5) l Shim / Safety / Regulating. Fuel followers for increased reactivity. (1.5) I

• REFERENCE Volume 1, pages 40-44, OSU Triga Manual P
• QUESTION B.6 L

Where may new and irradiated fuel be stored when not installed in the reactor 7 (1.0)

• ANSWER Fuel may be stored in the floor storage pits, Tank wall storage

rack, 2-(1.0) t

• REFERENCE Volume 1, page 40, OSU Triga Manual l

l i

,F A g

• QUESTION B.7 State the following design parameter or materials used for the

} OSU 1RIGA Reactor: (2.5) [ i a. Reflector material (s) used (two) L b. Fuel enrichment (FLIP) c. Length of active fuel I d. Fuel cladding material I i e. Control rod cladding material WANSWER a. Graphite and water (0.25 each) L b. FLIPS 70% (0.5) c. 15 inches (0.5) d. Stainless steel (0.5) [Alu%, m Deple koc.. e. Stainless steel (0.5)

• REFERENCE Volume i, OSU Triga Manual End of Section B k

Go on to Section C l f k I I e e' I I l I 2

o o [ t ( Section C General Operating Charachteristics i i

• QUESTION C.1 i

i The safety of a TRIGA reactor derives from its large prompt negative coefficient which is primarily due to an intrinsic 1 characteristic of the fuel. List the THREE contributions (not necessarily all from the fuel) which account for the prompt negative coefficient and expAain how each of them inserts reactivity on a payer increase. (3.0)

1. ANSWER ZrH disadvantage factor E0.43 as temperature raises the ZrH I

becomes less effective as a moderator. CO.63 Doppler effect CO.43 absorption cross sections of resonance peaks broaden as temperature increases. CO.63 a s 5 Neutron spectrum hardening E0.43. from the shift in the spectrum of thermal neutrons being pushed into the resonance peaks of the Erbium poison CO.63. i'

• REFERENCE f

Volume 3, 66-77, OSU Triga Manual A I E I \\ I I J t e _. _ ~,.

k e e 4

• QUESTION C.2 After three days of continuous operation at 200 Kw, the reactor is shutdown for minor maintenance.

It is restarted 8 hours later. f. a. How will the critical rod position at 200 Kw on restart y compare to the critical rod position at the time of shutdown? t EXPLAIN. k (1.0) ? 3 b. Describe the rod motion would be necessary over a 24 hour { period to go f rom just critical to 200 Kw and maintain that steady state power fa the next 24 hours? } (1.5) l

• ANSWER 3

a. The critical rod height on restart would be higher (0.5) due to the increase in Xenon during shutdown (0.5) which added negative reactivity. 1 b. Initially, rods must be withdrawn to increase power to 200 Kw. (0.5) As Xe is burned out from its peak value, rods must be I inserted. (0.5) i Eventually, Xe will reach a minimum value and will begin to l increase to its equilibrium value for the steady state power level. At this time, rods will have to be moved out to keep power constant. (0.5)

• REFERENCE Glasstone and Sessonske
• QUESTION C.3

} Explain how the radiation level from an experiment sample could be greater than one-half the original radiation level after passage of more than one half-life. (1.0)

• ANSWER If the parent isotope decays to a radioactive daughter (1.0).

[

• REFERENCE i

Foster and Wright, Basic Nuclear Engineering i I ( i

r-4 1 1 l + 1 s

• QUESTION C.4 h

Describe the process / mechanism that produces flow through the core during reactor operation. <2.5> i

• ANSWER Water flow through the core is by natural convection.

As the { water in the core is heated, its density decreases and it tends to ri se. It is replaced by cooler water, which heats and also l rises (2.5). i )

• REFERENCE General Physics Corp. " Academic Program for Nuclear Power Plant Personnel"
• QUESTION C.5 a.

In a control rod worth more at a center or a peripheral core location. 7 EXPLAIN (1.0)

b. How does the differential rod worth vary with it's axial position in the core ? EXPLAIN (1.0) l

1. ANSWER l

a. The centrally located rod is worth more as the flux is j generally higher. C1.03

b. A rod with it's poison tip located mid-core has higher worth than a rod at the top or bottom due to the higher flux in that region.

[ 1.03 (2:0)

• REFERENCE Glasstone and Sesonske, and General Physics Corp. " Academic r

[ Program for Nuclear Power Plant Personnel"

• QUESTION C.6

a. What is the average value of the fuel element worth in the "B"

j ring for the OSU Triga reactor? (0.5) !f

b. What significance does this worth it have for maintenance activities requiring removal of a control rod?

- (1.0)

t

{

• ANSWER

a. Approximately 45 to 50 cents.

(0.5)

b. During maintenance on a control rod several elements may have to be removed to assure the reactor romains sufficiently suber i ti cal.

(1.0)

• REFERENCE I t OSU Triga Manual, Questions and Answers.

1 i j, L f

• QUESTION C.7 i

With the reactor just critical at a power level of i watt. What j effect, if any would be observed if the neutron source were to be 4 removed at this point? (2.0) i

• ANSWER

} At low power levels the reactor may depend on source neutrons to } remain critical. (1.0) When the source is removed the reactor i could go subcritical and the power decrease to source level. -{ (1.0) I

• REFERENCE OSU Triga Manual, Questions and Answers

( l I t i. End of Section C Go on to Section D kevieway 644 < b 4,RfdV M DOL) l # m A \\ u< d AlrLosuu3<->mysQQ r m e ev. v. a I t I I i V T k e = l 1! f I i i o

Ir I Section D Instruments and Controls I

• QUESTION D.1 I

What two physical forms of radioactive effluent is the Stack Monitor designed to detect? (1.0)

• ANSWER l

Gas and particulate. (1,0) [

• REFERENCE Volume 1, page 148, OSU Triga Manual u
• QUESTION D.2 Explain how the fuel temperature indication system provides a f

reactor protection signal. (2.0) h

• ANSWER The sensing of a high temperature in the se1 meted fuel thermocouple provides a signal to a bistLble set to a nominal j

setpoint, the output f rom the bistable is sen to a relay in the l reactor scram circuitry. (@rst,*s m km. %,r .'a, (2.0) a

• REFERENCE Volume 2, figure 2.17, OSU Triga Manual

[

• QUESTION D.3 What are the INTERLOCK and PROTECTION outputs of the Log-N Power Channel? (Total of three)
• ANSWER 1.

1KW pulse inhibit.

2. Low source count inhibit.

f

3. Period scram.

CO.5 ea.3 (1.5) f

• REFERENCE Volume 2, figure 2.17, OSU Triga Manual

& % Y$ " f lN WpeoW eld s!d l )$h$wn Ce 5 h 'S s J a% yM y c w-c.w t 5

2 i

• QUESTION D.4 j.

a. How is control rod position determined? (1.0) h b. What functionally causes the CONT /ON light on the console to f illuminate? (1.0) y f'I

• ANSWER

[ A potentiometer ont the CRD provides input to the gensole rod a. ] position indication circuit. (1.0) (ca.6) @ jocdb. ~ b. That the magnet and the control rod have made contact. (1.0) [

• REFERENCE Volume 2, page 15, OSU Triga Manual
• QUESTION D.5 Which. detector type is used for each of the following ranges of nuclear instrumentation ?

( ) a. Log-N channel 1 'I b. Linear Power channel 'f

1. (v F

c. Safety channel d hi d. Percent Power channel (h> .i 1-e. Period channel

• ANSWER a.

fission chamber (0. [ y k' I ~ i 9n b. fission chamber ( 0.,21 c. uncompensated ion chamber (O.d (0.35)kkf d. uncompensat'ed ion chamber a c,.n :- A.k..L =r (0.8) $ff e. uncerpr.m::ted 17 J [

• REFERENCE l}

Volume 2, OSU Triga Manual I i t I l !j >i:[

's k {

• QUESTION D.6 What are the four (4) Reactor Safety Channels that must be operable per the Techical Specifications during pulsing operation 1

of the OSU Triga Reactor? (2.0) a p'

• ANSWER d

1. Fuel Element Temperature SCRAM I

2. Console SCRAM button I

3. Preset Timer I

4. High Voltage (0.5) each.

• REFERENCE Technical Specifica,tions Table I, page 12.

t L.

• QUESTION D.7 L

What type of device is use to determine Primary System Flow and what principle (i.e. theorum) does the device utilize to accomplish the determination of the flow rate? (1,5)

• ANSWER The device is (an Annubar) flow element. (0.5) The principle used F

is Bernoulli's Theorum (or relation of flow rate proportional to square root of delta P). (1.0) 5

• REFERENCE l

OSU Triga Manual, Volume 1, page 117.

• QUESTION D.8 The Demineralizer performance can best be optimized by monitoring two parameters. What are those two parameters and what instrumentation is provided for the purpose?

(1.0)

• ANSWER L

'1. Water temperature via thermocouples. (0.5) 2. Water conductivity via conductivity probes. (0.5) t

• REFERENCE OSU Triga Manual, Volume 1, page 116.

End of Section D 3, Go on to Section E !!!) ^ I {' i l u

'I .s 4.i I. [ Section E l Safety and Emergency Systems t k ?

• QUESTION E.1 I

What is the p'urpose of the safety plate installed beneath the j reactor grid plate 7 3 (2.0)

• ANSWER t

To stop a control rod follower (1" below it's normal down position), should it become detached from it's mounting. (2.0)

• REFERENCE Volume 1, page 14, OSU Triga Manual TAMU NSCR TRIGA SAR, p.

14 I

• QUESTION E.2 What are two (2) design features prevent an operator from acci-dently pulsing the reactor in the steady state mode of operation 7 7

t (2.0) 5

• ANSWER t

1. Air cannot be applied to transient rod unless it is fully down. I 2. Interlock prevents pulsing operations above 1 KW. t 3. Cannot withdraw transient, shim, and safety rods simultaneously. i-b ~ Interlock requires switch in pulse mode. Eany 2, 1.0 ea.3 4. (2.0)

• REFERENCE 7

Volume 2, pages 23-28, OSU Triga Manual i

• QUESTION E.3 There are four.(4) reactor scrams provided from the nuclear instrumentation. Describe the scrams, and the associated setpoints and/or conditions that cause these scrams.

(2.0) I

• ANSWER l

1. Safety channel power, 108% of full power. (0.5) 2. Percent power, 110% of full power. (0.5) r

3. Period, 3 seconds.

(0.5) 4. High voltage, loss or reduction of HV to any of the NI power supplies. (0.5) f

• REFERENCE k

Volume 2, CSU Triga Manual r

1 1 r L

• QUESTION E.4 h

What conditions other than scrams from the nuclear i instrumentation will cause a scram or partial scram of the { reactor? Include the parameter that causes the scram. (3.0) i

• ANSWER 1.

Preset timer, drops Transient rod after pulse. (1.0) F

2. Fuel Temperature, 510 deg.

C. (1.0)

3. External scram, beam ports etc.

(1.0) f p

• REFERENCE

-} Volume 2, OSU Triga Reactor

• QUESTION E.5 What signals / alarms and their associated setpoints will isolate the Reactor Bay Ventialtion system?

(2.0)

• ANSWER r

1. Stack Gas High alarm, 4.OE-6 micro-Ci/cc. (1.0) 2. Stack Particulate High alarm, 2.OE-10 micro-Ci/cc. (1.0)

• REFERENCE

[ Volume 2, OSU Triga Manual

• QUESTION E.6 After a prolonged power loss the emergency generator starts and supplies certain loads.

s i

a. How long after the power loss does the emergency generator

' start and' assume it's loads? (' 1. 0 ) r l

b. What are four (4) loads served by the emergency generator?

p (2.0)

• ANSWER

- ;~ a. 20 seconds. (1.0) b. 1. Lights in D-302 and hallway. g l4 2. T.V. monitor. lf 3. Stack Monitor pump. u 7 4. Cypher lock. 5. Fire alarms. [any 4 (0.5) each.3 (2.0)

• REFERENCE

~ OSTROP 22 l l t it L ~

g j

• QUESTION E.7 What feature is provided to prevent a loss of Reactor Tank water if a beam port should develope a serious leak?

(1.0) f

• ANSWER g

The beam port door can function (with the gasketing and screw j clamps) to close off the beam port to prevent leakage. (1.0) {. g

• REFERENCE

[ Volume 1, page 98, OSU Triga Manual i' End of Section E Go on to Section F t t e b {. a r l r r e e, I l l{ b p"" 'i'l ik ii 'I iF Ih I l' i 1.i . 2. :2:- T:~

it w L. Section F L p= Standard and Emergency Operating Procedures h \\ i l ~

• QUESTION F.1

[ When conducting pulsing operations: What is the maximum reactivity addition allowed? (1.0) a. b. What is the maximum permitted initial power? (1.0) ?

1. ANSWER l

g (2 6C) adm/% k.*w *t. a. Current limit is about $2.55. (1.0) h b. 1000 watts (1.0)

• REFERENCE s.S.

3.3

• QUESTION F.2 What is the major difference in control rod manipulations for a steady state startup versus a startup for pulsing operations ?

(1.0) r' r -* ANSWER During a startup for pulsing the transient rod is not used to attain criticality. (1.0)

• FtEFERENCE OSTROP 4 r

L r ~ s.. I L

i g

i E 'L

I,

i

• QUESTION F.3

{ Technical Specification 4.4 requires an annual fuel element inspection. What are the 3 checks performed on a fuel element } during this insp12 tion 7 f (1.5) >t

• ANSWER l

a. 1. Transverse bend i.

2. Elongation f

3. Visual defects I (1.5) }

• REFERENCE T.S.

4.4 h

• QUESTION F.4 i

During steady state operation at 1 MW, an alarm is received for " CAM HIGH ACTIVITY".

a. Besides a fission product release, what are :2 other possible reasons for this non-spurious alarm to occur ?

(1.0) )[- [ b. As Reactor Operator, what action will you take if the alarm is

[

valid, and a fisrion product release is occurring ? (1.0)

• ANSWER a.

o Temperature inversion. [ o High airborne activity due to operation or sample leakage. o Movement'of source or sample close to CAM. o Release of disdolved gasses from the reactor tank after a prolonged shutdown. l Any two (0.5) nach. (1.0) l ({.

b. Scram the reactor and notify Reactor Supervisor.

lg (1.0)

• REFERENCE f

OSTROP 1.5 i I, 1 k 1 + h i [l i i i

Lt i [

• QUESTION F.5 L

Answer True or False for the followings (1.5) {

a. The reactor shall nst $c operated unless the shutdown margin provided by the control rods, under the most conservative j

conditions, is greater than $0.25. b. The FLIP fueled region in an operational core shall contain at [ 1 east 80 fuel elements. J.

c. The scram time measured from the time a rod starts in motion h

to the time the fod reaches a fully inserted position shall not exceed 1.2 seconds f or the slowest scrammable rod. s-

• ANSWER 6

a. False (0.5)

b. True (0.5)

~

c. False (0.5) c

• REFERENCE-T.S.

3.2, 3.4, 3.5.1 i

• QUEGTION F.6 E

10 CFR 55 defines an " operator" as any individual who manipulates f a control of a facility. a. Define the term " control" as used in this context. [ (1.0) ? b. Under what condition is the person physically manipulating a control not required to hold a valid operator's license? t (1.0) r l 7

• ANSWER Apparatus and mechanisms of a nuclear reactor, the a.

manipulation of which directly affect the reactivity or power level of the reactor. ( 1 '. 0 ) II b. The individual manipulating the control must be und.er the } direction of a licensed operator (and be a trainee for a

l license or a. student under instruction.)

~ (1.0) [r

• REFERENCE l

10CFR55

)

l. L i I l L. ~ -

L

• QUESTION F.7 J

-Answer the following with regard to the Reactor Power Calibration ( Procedures p a. At what power level is the calorimetric performed? (1.0) [ b. Which channel (s) is(are) actually adjusted to agree with the { calculated reactor power? If all channels are not adjusted to agree with the calculated power, what are they adjusted to? (1.0) eANSWER (/ weg c. wek w / k c.4Awm4(w* d yN. a. 100 Kw (1.O) L b. Linear channel is adjusted to calculated power (0.5). The other channels are adjusted to agree with the' linear channel ~ (0.5). L

• REFERENCE l

OSTROP 8 1

• QUESTION F.8 1

OSTROP 18 " Procedures for the Approval and Use of Reactor Experiments" describes the classifications for Reactor Experiments. What are the three (3) types of classifications, f include a description of a typical experiment for each j classification? (2.0) I

• ANSWER l

1. Class An'Small changes in reactivity, limited radioisotope p production. (0.67) 2. Class Be Large changes in reactivity, larger amounts of [ radioisotopes. (0.67) l6 3. Class C: Unusual experiments, irradiation of explosives, { 1arge incore facilities, etc. (0.67) (One example for each Class sufficient.) ? '{

• REFERENCE

( t OSTROP 18 1 'l

s 1

f y 1 1: 1 . - _ - -..___ - -_ = = = ====== : z =::- -:.__-,-_-

= 1 4 , l- - y

• QUESTION F.9 For each of the following Emergency Classifications what is the type of event or emergency as defined in the Emergency Response Plan?

(f.5) 7 a. Class O r b. Class I f

c. Class II f

d. Class III i }

e. Class IV

• ANSWER a.

Personnel and operational events. p 4

b. Notification of Unusual Event c.

Alert f d.[ Site Area Emergency ,j ] q(( f,- g e.(General Emergency I**Oy *0 6' ' (0.5) each. o

• REFERENCE OSU Radiation Center and Triga Reactor Emergency Response Plan.

I End of Section F Go on to Secti'on G L i 'r ? I i ff k ,,n-..,.- - - - - - - - - - - ~, - - - - - - - - - - - - - -

\\N a-sa g g, f v d Section G Radiation Control and Safety I-j

• QUESTION G.1 An irradiated experiment that measures approximately 6" x 6" x 6"is surveyed with a Cutie Pie survey instrument. The open window

{ indication is 5.3 R/hr. and the closed window reading is 3.5 R/hr. at a distance of 2 feet, the Beta Factor of the Cutie Pie has been determined to be 4.5. 1 a. What is the Beta dose rate at two feet? (1.0)

b. How long could you remain at the survey distance of two feet y

without exceeding the 10CFR2O quarterly whole body limit? (1.0) c. What would the instrument closed window reading be if you moved back to a distance of 10 feet from the experiment? (1.0) j

• ANSWER a.

Beta rate = (open -closed) X Beta Factor =(5.3 -3.5) X 4.5 k 0.1 R/hr. = (1.0) f b. Quarterly limit 1.25 R time = 1.25 R / 3.5 R/hr. x 60 min /hr. 21.4 min. = , (Based on gamma only) (1.0)

c. 3.5R x (2ft.)2 = Dose x (10ft.)2

= 3.5 x 4/100 .=.14 R (1.0)

• REFERENCE 10 CFR 20, ART. 101 1

[7 7 q_o' 7- = \\ f 3 .3.5 2b~ 1 y n ty

f. o-i r_

3 o c. rm

f. O[

S i _,m

I = a. i

• QUESTION G.2 Match a Quality Factor to each Radiation Type. (Each GF may be used more than once or not at all) Consider DNLY EXTERNAL j

exposure. (3.0) j a. Gamma rays 1. 20 .b. Thermal neutrons 2. 15 i

c. Fast neutrons 3.

10 d.' Alpha particles 4. 2.3 e. X-rays

5. 2 f.

Beta particles 6. 1 f

• ANSWER 7.

O a.------------6 L b.------------4 c.------------3 d.------ - - -7 e.------------6 f.------------6 EO.5 each3 (3.0) +

• REFERENCE 4

WJE 284 i

• QUESTION G.3 For the Area Radiation Monitoring Systems What types of detectors are emp1.oyed?

a. (1.0) i b. What types of radiation can be measured by each of these detectors? ( 0.- 5 )

• ANSWER a.

G.M. and Scintillation. (1.0)

b. Both detect Gamma.

(0.5) 1 e

• REFERENCE ll OSU Triga Manual Volume 5, page 17.

e i i 1, 1 1 t

m y-

1.... *

( L L

• QUESTION G.4 Define or explain the following terms:

/ a. Biological half-life E1.03 [

b. Effective half-life E1.03 (2.0) k

[

• ANSWER

'{ The time it takes the body to rid itself of half the amount of a. a substance due to natural elemination. E1.03 t b. The time it takes the body to rid of half of a substance due to biological elemination AND radioactive decay. E1.03 (2.0) y

• REFERENCE WJE 297

'f

• QUESTION G.5 List the three (3) basic f actors which af f ect an individual 's dose in a radiation area AND describe how the dose would vary j-with a change in each of the factors.

Assume a point source. i (3.0) ii

• ANSWER t

1. Time (0.5). Dose varies linearly (0.5). 1 .I 2. Distance (0.5). Dose varies as the inverse of the distance j squared (0.5). [ 3. Shielding (0.5). Dose varies exponentially (0.5).

• REFERENCE

[ Basic Radiation Protection t: l I s e O 9 I f

y-N ..f I

• QUESTION G.6 Five (5) types of personnel monitoring devices or dosimeters are availiable at the Radiation Center for reactor operations personnel. What are four (4) of those devices or dosimeters?

ii

• ANSWER (2.0) a.

Film badge. b. Neutron badge. c. Pocket ionization chamber. t d. Finger ring. e. Audible radiation detector. I Any 4 (0.5) each. I'

• REFERENCE L

Radiation Protection by Shapiro, pg 46 - 47 ) 10 CFR 20, part 20.101 l End of Section G I End of Examination i t I I E l y l 4 p' J - i - ~.,,, _ - _ _.. _.,. ,}}