ML20128G413

Exam Rept 50-288/OL-85-01 on 850514-16.Exam Results:Three Senior Reactor Operator Candidates Passed,One Failed & Three Reactor Operator Candidates Failed

ML20128G413
Person / Time
Site:	Reed College
Issue date:	06/24/1985
From:	Elin J, James Smith, Upton J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
Shared Package
ML20128G408	List: ML20128G405 ML20128G413
References
50-288-OL-85-01, 50-288-OL-85-1, NUDOCS 8507090182
Download: ML20128G413 (98)

Text

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6

. EXAMINATION REPCRT FACILITY LICENSE: Reed College Portland, Oregon FACILITY. DOCKET NO.: 50-288 FACILITY LICENSE NO : R-112 Examinations administered at Reed College in Portland, Oregon.

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Chief Examiner: / Tb4 b ' 2. f'df 5 Joh .D. Smith Date Signed Examiner: , . f4 4. 6 Y Dr// J.' W. Upton, Jr. -

Date Signed

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Approved By:

- - $ (rd John Elin,,Section Leader D4te Afgned i V s

SUMMARY

i

> Examinations'onMay14-16,'k985

-Mr. Ron Maines, NRC Headquarters ~, was in attendance solely for the purpose of certifying Dr. Joseph W. Upton, Jr., as a research reactor license examiner.

Dr. Upton was certified during this visit.

Written examinations were administered to four (4) SRO candidates and three

-(3) R0 candidates. Oral examinations were administered.to three (3) SRO and two (2) R0 candidates. One (1) SRO and one (1) R0 candidate declined to take the oral examination. This resulted in an automatic denial of these licenses.

Three (3) SR0 candidates passed these examinations. All others failed.

8507090182 850702 PDR - ADOCK 05000288 G PDR

I REPORT DETAILS

1. EXAMINERS.

., J. D. Smith, PNL, Chief Examiner J. W.-Upton, PNL, Examiner

.2. EXAMINATION REVIEW MEETING-At-the conclusion of the written examinations, the examiners met with M. Kay and Q. Hanley of the Reed Reactor Facility.to review the written examinations and the answer keys. As-a result of the review, changes were made to the exam key as described in the enclosed facility comments and resolution.

3. -EXIT MEETING-At-the conclusion of the site visit the examiner met with'Dr. Michael Kay of the facility staff to. discuss the results of the examinations. Those individuals who clearly passed the oral examination were identified in this meeting. The examiners made the following observation concerning-the training program.

a.: An area of generic weakness was found related-to what to expect and how to proceed in-the event of a total loss of offsite power. No procedure is written for this event. The facility committed to place more emphasis in this area in future' training programs.

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$ 4 3

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3

3 e l FACILITY COMMENTS AND RESOLUTION Comment Resolution

'Ans. A.4 Answer incorrect for K,ff Key incorrect. Changed to 11.7 cpm of 0.88 Ans. B.1 Drawing in key incorrect Current drawing supplied by facility added to key Ans. C.5 Answer incorrect Key in error (typo), answer changed to "d" Ans. C.7 Samples are dropped by Key changed to reflect new loading gravity into Lazy Susan). technique.

Ans. F.1 - 4 '

Hi/ low water alarm Key changed to hi/ Low Ans. H.1 Cell and inhomogeneties Key changed to accept Zr H for not taught. 2 H is largest largestcontributor Ans. H.4

. 8 = 0.0075 at RRF Key changed to-accept either

, N -51.37 or %-51.28 Ans. H.S Generation time. is 12.3 sec. Key in error changed, l time to 12.3 sec.

Ans. 1.9 Answer is yes Key in error, changed to yes t-Ans. J.1 - 1 % 106', Key changed to reflect current values

- Current -2 4 sec. and terminology val ues - 4 % 107%

and - 5 Hi voltage l terminology - 6110 AC power

-Ans. J.2 Added dashpot action to key or dashpot action Ans. J.3 May give setpoint which is No change to key

<6 cps l

N P +-

.r- t- v g -- -y w rw- t '

n-r 4

• 1

. 4 Ans. J.4

' No calibrate position on range Change key to read:

switch only linear calibrate " Reg. rod insertion if on 250 KW range, linear scram if on any other rangen An s '.' J . 7 i May use rule of thumb to Accept 1*C per 103.5 KWH ^%112*F calculate -

Ans. K.2 s10' Changed key to 410' Ans. K.3 Answer. specific to Reg. Rod No change to key Ans. K.4 51.35' fixed = Added $1.00 moving to' key ,

51.0 moving Ans. K.7 Drawing incorrect Current drawing supplied by Facility added to key-Ans. K.8

' Although in lesser quantities, No change to key .

bromine will escape too Ans. K.10 Current worth a.~%$4.50 Key changed to -reflect current values

b. 454.50

c. 451.80 Ans. L.2=

ROC approves restart from Changed key to read inadvertent scram

unexplained scram Ans. L.6

-<53.00 Tech Spec limit No change to key k

, U.S. NUCLEAR REGULATORY COMMISSION SENIOR REACTOR OPERATOR LICENSE EXAMINATION Facility: REED COLLEGE Reactor Type: TRIGA Date Administered: MAY 14, 1985 ,

Examiner: SMITH /UPTON Applicant: ANSWER KEY M 3 J T / 4

)

INSTRUCTIONS TO APPLICANT:

Use separate paper for the answers. Staple question sheet on top of the answer sheet. Points for each question are indicated in parenthesis after the question. The passing grade requires at least 70% in each category. Examina-tion papers will be picked up six (6) hours after the examination starts.

Category  % of Applicant's  % of Value Total Score Cat. Value Category 20 20 H. Reactor Theory 20 20 1. Radioactive Materials Handling, Disposal, and Hazards 20 20 J. Specific Operating Characteristics 20 20 K. Fuel Handling and Core Parameters 20 20 L. Administrative Procedures, Conditions, and Limitations 100 TOTALS l Final Grade  %

All work done on this examination is my own; I have neither given nor received I aid. l 1

Applicant's Signature

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, H. REACTOR THEORY _jgo) -~

Points QUESTION H.1 Give the three (3) effects (components) that contribute to the large prompt negative fuel-temperature coefficient of the TRIGA Fuel, and indicate which has the largest and which has the smallest. (3.0)

ANSWER H.1 Cell and inhomogenities (largest) (+1.0) ACUFF Za N AS 44ccrrr s Doppler (+1.0) (cht Aud <~ H e

• C r ev e r ' 33 M:7 7d "Cd7 )

Core Leakage (sniallest) (+1.0)

Reference (s)

G.A. TRIGA Training Manual, Chapter 6, paragraph 6.2.3.

- Section H continued on next page -

a

, 2 Points Available OUESTION H.2 Answer the following TRUE or FALSE (and briefly explain your answer):

(a.)- If the Half-life of I-135 was 1arger than the half-life of Xe-135, the Xe-135 concentrations would not build up to a peak following a shutdown after an extended operation. (1.0)

(b.) The time it takes to achieve peak Xe conditions foliowing a shutdown (SCRAM) is independent of the preceding equilibrium power level. (1.0)

(c.) The equilibrium Xe-135 concentration at 50% power is less than half the Xe-135 concentration at 100% power. (1,0)

ANSWER H.2 (a.) TRUE. The slower decay time (half-life) of the precursor would govern and not the induced concentration (buildup of Xe). (+1.0)

(b.) FALSE. The lower the equilibrium power, the earlier the xenon peaks. (+1.0)

(c.) FALSE. It is about 70% due to higher burnout factor or Xe-135 at 100% power. (+1.0)

Reference (s)

G. A. TRIGA Training Manual, Chapter 6, paragraph 6.3.7

- Section H continued on next page - ,

f 3

. Points Available OUESTION H.3 If the Reactor is shutdown by 5% delta k/k with a count rate (CR) of 10:

a. How much positive reactivity would have to be added to double the count rate? Show work. (1.0)

b. How much negative reactivity would have to be inserted to reduce the count rate by 1/2? Show work. (1.0)

c. Explain why there is a difference between the values obtained for part (a.) and Part (b.) above. (1.0)

ANSWER H.3 CR CR

a. 2 = 1-X1 2 1,g 2 k' 1-K g 2=7 2 2-K2

• l-X1 Kg+1 K

K2" 2 - 1 0.05 - 0.95

' + = 0.975 K2" z Reactivity added = 0.975 - 0.95 = 2.5% delta k/k l

1

- ANSWER H.3 continued on next page - l

. I i

' ~ ~ ' '

e 4

+ Points Available ANSWER H.3 (contd)

CR CR

b. 2 = 1-K1; 1 2=7 g 1-K g 7" K 1 1

-.7 7 K2 " l-Ki 1-K2 = 2-2Kg K2 = 2Kg - 1 Where Ky = 1-0.05 Ky = 0.95 K2 = 1.90 0.90

' Negative reactivity inserted = 0.95 - 0.90 = _5% delta k/k

c. The count rate is inversely dependent on delta k. Hence, for any initial value of delta k and CR it will take more change in delta k to reduce the CR than to increase the CR.

Reference (s)

G.A. TRIGA Manual, Chapter 6, Reactor Theory.

- Section H continued on next page -

m-5

• Points QUESTION H.4 Calculate the reactivity change (delta k/k) in dollars and cents which would occur if the reactor water temperature is maintained constant and the fuel temperature is increased 100*C. (1.0)

ANSWER H.4

9. A%

-9.6 x 10-5 x 100 = -9.6 x 10-3

-9.6 x 10~3 = -$1.37 e4 - $ l gg ,F .oo7T v J # ^# # 'I /

7.0 x 10-3 Reference (s)

G. A. Training Manual, Chapter 6, Reactor Theory, pp. B-2.

(CAF)

- Section H continued on next page -

4

• 6 Points Available OUESTION H.S 7 Explain why the delayed neutrons have such a large effect on the operators ability to control the reactor when the ,

delayed neutron population is only about 0.6% of the total neutron population in the core. (2.0) i ANSWER H.5 Even though the percentage of delayed neutrons is small, their relative effect is great because their generation to generation time may be on the order of1t=w=MF3 seconds.

( z . '3 I

The effective On lifetime is:

(% prompt On I ) (lifetime prompt neutrons) +

(% delayed On I ) (lifetime delayed neutrons)

Reference (s)

G.A. Training Manual, Chapter 6, Reactor Theory.

t

- Section H continued on next page - ,

1 l

,' 7 Points QUESTION H.6 Doubling the time a target nuclide is irradiated wil) .

(Select from the following the statement that correctly completes the sentence.) ,

(1.0)

a. double the activity

b. more than double the activity

c. less than double the activity ANSWER H.6 Less than double the activity which results from the decay of thenuclidegeneratedexprygsedintermsofitsdecayconstant A as the decay factor (1-e )

Reference (s)

Stephenson, McGraw-Hill.

- Section H continued on next page -

,- .-,----c----- . - ~ - - -+- , - - - - - - , , - - . - , , - , , - -

8 1*

Points Available QUESTION H.7 if_ the REED Reactor is taken critical and maintained on a stable 25 second period, how long will it take to increase power level two (2) decades. (Show your calculation). (2.0)

ANSWER H.7 T = 25 seconds SUR = 26 06 = -

= 1.0424 SURt P = P,10 SURt h=100=10 o

2 = SURt 2

t = 1.0424 = 1.92 minutes or P=P g q,t/T ho= 100 gt/25 sec Ln_100 = t/25 t = (25) (Ln100)

= ,115.13 second = 1.92 minutes

- Section H continued on next page -

' 9 Points Available QUESTION H.8 Explain what is meant by a dollars worth of reactivity in tems of K-effective and the delayed neutron reaction (Beta). (2.0)

ANSWER H.8 s=f8 K -1 Where p = reactivity = g,ff eff 1

and 8 is the delayed n fraction o

Reference (s)

TRIGA Training Manual, Section 6.2.4, pp. 6-12.

QUESTION H.9 Which of the following factors plays the most important role in detemining the worth of a control rod? (Select one) (1.0)

a. The flux shape

b. Reactor power

c. The value of the delayed neutron fraction

d. The rod speed ANSWER H.9 a.

Reference (s)

Stephenson, R. McGraw-Hill

- Section H continued on next page -

10

. Points Available QUESTION H.10

. A thermal neutron is: (Select one) (1,0)

a. A neutron possessing thermal, rather than kinetic energy.

b. A neutron that experiences no net change in energy after several collisions with atoms of the diffusing media.

c. A neutron that has been produced in a significant time (on the order of seconds) after its initiating fission took place.

d. The primary source of thermal energy increase in the reactor coolant.during reactor operation.

ANSWER H.10 b.

Reference (s)

Stephenson, R. McGraw-Hill

- Section H continued on next page -

, 11 Points Ava'lable QUESTION H.11 Which of the following statements best accounts for the fact that irradiated fuel elements are radioactive?

(Select one) (1.0)

a. The high-neutron flux activates impurities in the fuel cladding and matrix, therefore yielding radioactivity.

b. Fission products, like the parent U-235 atom, are very

. neutron rich, and therefore tend to decay into more stable elements via beta minus decay.

c. Uranium is highly radioactive, and becomes even more activated under a thermal neutron flux.

d. Af ter fission the fission products are very neutron deficient and therefore decay into more stable elements via beta plus decay.

ANSWER H.11 b.

Reference (s)

Stephenson, R., McGraw-Hill

- End of Section H -

8

. , - . , , - , ,- -- n., , ,,_ , - -.-, --- - - - . , - ,- -, ,.w- --.- ,-- w.--

12

. I. RADI0 ACTIVE MATERIALS HANDLING, DISPOSAL AND HAZARDS (20.0)

Points Available.

QUESTION I.1 Briefly describe the construction and principle of a thermo luminescent dosimeter (TLD). (2.0)

ANSWER I.1

_A Jn reasonable explanation incorporating the use of lithium Duoride as the detector and the use of heat and light sensitive equipment to measure the exposure will be accepted.

Reference (s)

Reed Reactor Theory Training Manual, pp. 2-42/43.

QUESTION I.2 What is the advantage of a TLD over a film dosimeter? (1.0)

ANSWER I.2 Film badge susceptible to aging, also requires interpretation of exposure.

Reference (s)

Reed Reactor Theory Training Manual, pp. 2-40/41.

i

- Section H continued on next page -

- - --.--- r+ *g --y-,w- - - - - - - - - . -----e,r----.. y -.---------- - -%r-- - - y-- .vs- , _ .,

l

. l T.I 13 l l

Z. I Thermoluminescence Dosimetry or TLD ,

Phosphors that have been used the most in studies of l thermoluminescence include manganese-activated calcium fluoride (CaF 2 :Mn) and lithium fluoride (LiF).

Other substances, such as, CaSO4 :Mn, MgF2

Hn, and Al 230 , have also been used. In these '

65 stances, electrons are moved from cheir normal places when the-Bolid is exposed to ionizing radiation. They migrate about until At normal temperature, f trapped" by lattice defects in the solid.

the electrons remain there for quite some time, but are released from the traps by heating. The luminescence appears when the L

' electrons return to their normal positions. This light can be

'amasured and related to the absorbed dose in the phosphor.

2 For readout of the accumulated absorbed dose, the phosphor

,is heated electrically and the intensity of the resulting luminescence

'is measured by a photomultiplier tube whose output signal is applied I

to a suitable readout instrument, such as an ammeter. The instrument is calibrated by measuring the intensity of light from phospors it hat had been exposed to known doses of radiation. Since the

' intensity of luminescence is proportional to the quantity of the

' phosphor as well as to the radiation absorbed dose, the amount of fphosphor used in making a measurement must be kept as close as

!possible to the amount used in calibrating the instrument.

I Thermoluminescent dosimeters respond quantitatively to fX-rays, gamma-rays,betasandprotonsoverarangethatextends tfrom about 10 mrad to about 100,000 rad. LiF thermoluminescent l ' dosimeters are approximately tissue equivalent. The response of a LiF thermoluminescent dosimeter is almost energy independent from

'about 100 kev to 1.3 MeV gemma-rays.

- Section I continued on next page -

. 14 Points Available QUESTION I.3 Explain the Reed Reactor design feature that reduces gamma activity above the pool associated with N-16. (2.0)

ANSWER I.3 The discharge line for the TRIGA Mark I reactor terminates in a flow deflector box just above the core where approximately 2/3 of the discharge flow entering the deflector box is discharged at right angles to the sides of the reactor tank through a slit in the side of the box. This action increases the flow time of radioactive gases from the core to the surface of the coolant shielding' water, thereby providing a longer decay time for short-lived radioisotopes. The remaining 1/3 of the inlet flow is dis-charged toward the bottom of the tank through an orificed pipe attached to the bottom of the deflector box.

Reference (s)

Triga TM, p. 1-30.

- Section I continued on next page -

. 15 Points Available QUESTION I.4 Explain how radioactive contaminants are removed from the reactor coolant. (2.0)

ANSWER I.4 Particulate by filtration soluable by ionic exchange.

Reference (s)

Reed SAR 5.2.6, pp. 5-7.

QUESTION I.5 Define the following at the Reed Triga facility.

a. Radiation area. (1.0)

b. High radiation area. (1.0)

ANSWER I.5

a. >5 mrem /hr - >500 mrem /5 days.

b. >100 mrem /hr.

Reference (s) 10 CFR 20. -

- Section I continued on next page -

16 Points Available OVESTION I.6 Which decay mode listed below is closest to that of:

a. AR-41 (0.5)

(1) t1/2 = 3.81 hr-beta minus decay - no gamma.

e.1 (2) t1/2 = 1.83 hr-beta minus decay - 1/2 mey gamma.

(3) t = 7.35 sec-beta minus decay 8 mev gamma 1/2 (4) t = 21.7 min-beta plus decay - no gamma 1/2

b. N-16 (0.5)

(1) t1/2 = 1.83 hr-alpha decay - no gama e.2 (2) t1/2 = 35.7 sec-beta minus decay - 1/2 mev gamma (3) t1/2 = 7.35 sec-beta minus decay 8 mev gamma (4) t1/2 = 21.7 min-beta plus decay - no gamma ANSWER I.6

a. (2)

b. (3)

Reference (s)

Stephenson, R., McGraw-Hill.

- Section I continued on next page -

• 17 Points Available QUESTION I.7 If two (2) centimeters of lead will reduce gamma radiation level from 100 mr/hr to 50 mr/hr. How many. centimeters of lead will be required to reduce a gamma radiation level from:

a. 400 mr/hr to 50 mr/hr. (1.0)

b. 50 mr/hr to 25 mr/hr. (1.0)

ANSWER I.7

a. 6 cm

b. 2 cm Reference (s)

Reed Reactor Theory Training Manual (Half-Value), pp. 2-27.

QUESTION I.8 Explain how both liquid and solid radioactive waste is '

handled and disposed of at Reed college. (2.0) r ANSWER I.8 The essence of SOP-52 (Radioactive Materials Transfer) will be accepted for an answer.

L t pys D J Atti ,fou Di f oE d. Sol t al Ali fo4cWAGis)

/ At .r*/dt ro c* c o y s w sneJ Mwc .tw A*<*c? T** /NkR LO

- Section I continued on next page -

7.3 17 au RADIQ4CTIVE MATERIALS TRANSFER soo32

'4 f- 5241 PURPOSE!

se', To comply with Federal

' and State Regulations requiring RRF to keep track of all radioactive materisis leaving tho' reac-p! tor facility such as irradiated samples, produced isotopes, sit and source s o f all types.

ii "

i:i 32 2 FREQUENCT!

s Whenever any radioactive materials are shipped or removed ll*! from RRF or transferred to the Reed College licence.

sg- 52a3 SPECIAL EQUIPMENT!

j' Too RADIDACTIVE MATERIALS TRANSFER forms separated by a sheet o f carbon paper.

f A completed 14 form (for irradiated samples).

A portable GM monitora l The los background GM coun ter.

s One Kimeine Methahol

. 5244 PER$0NNELt

/ljj!

One RRF staff membora The person (s) removing / shipping the radioec tive materials.

(These may and have, at times, been one and the s ame) 1 5245 PRELIMINART ACTIONS!

, j 5et up the too background counter in the reactor room and

start a five minute background count.

l o l 5246 PROCEDUREt i

Fill out the first two sections o f the RADI0 ACTIVE MATERIALS tRANSPER form obtaining the transfer number by ad ding one to

. l the latest transfer number posted on the blackboard. Check the appropriate box for materials shipped or removed (ma-terials removed are those tak en away by the experimenters l-themselves rather than being shipoed via a public carrier.

"~ Indicate the means of transport used in the box provided le. -

. private autel UPS, etc. The reciolents license number must

! be found on a copy of their current licence in the console i Poom file cabinet. No material shall be released without a

,! copy of the recipien t's licence on file 6 Indicate the gel-

'l -

oral type of materi'ai being transf erred, whether geological

,samplese physiological salinee etc. and the estimated activ-  !

'l ity in mil 11 curies.

Before pack 4ging, monitor the material itself

'l' from its surface with at one foot the GM portable wonitor and record this reading on the trant,fer form. After packaging, monitor l

the package .at its sveface and at one meter from its sur- l

,' face 4 Next) mois ten a Kissipe eith methanol and eine a

'I representative area,urus11y a bottom edge and corner and the (I top and closure of +$e con tainer and place the kimelpe in ll the los backgraind counter for a one sinute count and deter-mine the not beta-gamia counts above back- ground, record all of this monitoring information on the trandsfer form and applicable parts in the appropriate olanks of the IR forne

!), In the blank for remarks record the type o f packaging, la-

~

l

' 17 b RADIDACTIVE MATERIALS TRAN3FER:

sop 52 v-belling, and any other useful information about the package gs  :; and shipping procedure. See the aopendix to this sop and the Summary of Federal Regulations for PackaJing and Tran-

!-l sportation of Radioactive Materials to be found on file in gs the console room under " shipping information" for further information.

%s  ; 52a7 ADJUSTMENTS:

Insure all labelling on the packages to be shipped or that

,, renoved is correct and that the materials are not in viola-vl tion of the applicable state and/or federsi regulations by I

l adding more shielding or packaging, or by breaking a large i shipment up into smaller ones.

.)  !

• 5248 CLEANUP:

Check to see that all blanks have been filled in and that t

,s . all signatures have been obtained on the transfer form and I 1R Make sure the package has a seal such as tape or

, form.

l' sire 6 Give the carbon of the transfer form and the orange s!! sheet of the I,R to the experimenter / shipper with the materi- I l: als involved and file the_ originals in the console room fil-I ing cabinet. Turn off the los background counter and the s portable monitors 6 5249 LOGGING IN:

s Log the shipment in the console log book and update the

" latest transfer" number on the blackboard.

k j; $2610 APPENDIX:

l '"

Useful information from the Summary of rederal Regulations foe Packaging and Transportation of Radioactive Materials:

Jlj"\

l . Is Removable centseination is considered insignificant if

! the not beta-gamma count is < 2,200 dos /100sq.cm.

!j' II4 Labelling!

A4 shite radioactive I' label: < 0.5 mR/hr at surface -

86 yelios radioactive II label:

l 'l ! " < 10 mR/hr at surface yI  !

< 0.5 mR/hr at 1 meter or Transport Index < 0.5

! lll.

, C4 yellos radioactive III label: > 10 nR/Hr b l-fissile clas s III see Federal Rogs.

l "I III4 Peck Aging!

Pack a g e sust have a seal over opening to ensure

! contents arrive undisturbed ie. tape or lead wire.

No dimension of the package may be less than 4" for br shipping by public carrier.

l No , pack age may read > 200 mR/hr at its surface or

! n ) 10 mR/hr at 1 meter for postal b l shipping.

l 't W -

g l inst revised 08/1T/81 l I. i

i 18

. Points Available QUESTION 1.9 Which of the following isotopes has the longest half-life? (1.0)

a. Cobalt 60.

b. Nitrogen 16.

c. Argon 41.

d. . Xenon 135.

ANSWER I.9

a. Cobalt 60.

Reference (s)

Stephenson, R. , McGraw-Hill.

QUESTION I.10

a. Define rem. Clarify whether or not a rem is a measure of energy, or a measure of biological damage. (1.0)

b. Is a rem received as a result of alpha radiation equivalent to a rem received as a result of gamma radiation? Expl ain. (1.0)

ANSWER I.10

a. Rem reflects the amount of energy dissipated and biological damage derived from such energy dissipation.

Yir

b. g. Alpha has quality factor X20. INo o vi>FJ Reference (s)

Reed Reactor Theory Training Manual, pp. 2-2/3.

- Section I continued on next page -

,i,.- _g, .,,

.--.---e- -----w- v -----T --

19

. Points QUESTION I.11 Explain what might be potential sourct.s of radiation above l the pool under both nomal and abnomal conditions. (3.0)

+ / ,

ANSWER I.11 N-16.

Direct radiation.

Leaking fuel (I-131, xe-135, etc.).

Reference (s) i Generic.

s ,

End of Section I -

,i l

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A 20 J. SPECIFIC OPERATING CHARACTERISTICS (20.0)

Points Available OUESTION J.1 List the six (6) scrams possible at the Reed Triga -

Yiac' tor. Include setpoints where applicable. (4.0) 1 ANSWER J.1

1. Rx power 20-110% adjustable vic. 4rws4< PO've d / o (o 'A

2. Rx period <3 sec adjustable to inf. f o#e,o o s, f e

3. Manual.

4. Rx power CIC. g ro .s /<c f o 7 9.

5. Ion chamber power. supply. g, c, a vo e rAc #

6. Console power failure. < / o r d<:-

Reference (s)

Reed SAR, pp. 5-16.

QUESTION J.2 What facility design feature reduces the impact of a control rod when the reactor is scramed. Explain. (2.0)

ANSWER J.2

, Slot tyoe shock absorber added to control rod.

pA.rxPs Y Ac 2,o n Reference (s)

Reed SAR, pp. 5-11.

t

- Section J continued on next page -

l -

21 Points Available 00ESTION J.3 Describe the activation and function of the control rod interlocks at the REED TRIGA reactor. (3.0)

ANSWER J.3 No control element withdrawal with <2 neutron induced counts per second.

Simultaneous withdrawal of two (2) control elements.

Reference (s)

Tech. Specifications, p. 9.

QUESTION J.4 Explain the effect and possible result of switching the reactor power range switch to the calibrate posi-tion while operating in the automatic mode. (2.0)

ANSWER J.4 Will result in a regulating rod withdrawal and possible period or power scram.

Reference (s) ggg gg9 , g g ,c yi s e i; og fys Triga-Generic. 2 S'<.7 TN d 44c'. .fX 4/"N #C' * '

oJ py o rM4 A 4~'G d .

- Section J continued on next page -

q_m.-.n _ _y .

y - ., y ,_..r-_ ,, ~ , -

. 22 Points Available QUESTION J.5 TRUE or FALSE: As criticality is approached, the

'wfEEdrawal increments should be increased. Explain. (1.0)

ANSWER J.5 False. Should be lessened. Possibly too short of a period.

Reference (s)

Triga-Generic.

QUESTION J.6 Explain why it is undesirable to have too high of a flow rate through the demineralizer. (2.0)

ANSWER J.6 Too high a flow rate will produce channeling and possible flushing of particulates

- Section J continued on next page -

23 Points Available OUESTION J.7 Assume the combined specific heat of the reactor coolant / reactor components is 0.8. If the reactor coolant is at 70*F, and the reactor is operating at 200 kw when the secondary cooling system fails.

a. How many BTUs will have been added two (2) hours after the TaTTure? Show calculation. (1.0)

b. What will the reactor coolant temperature be three T3Thours after the failure?' Show calculation. (2.0)

c. What is the Tech. Spec. limit on pool temperature?

(1.0)

ANSWER J.7

a. 13.651 x 105 BTU.

a q r zu y

b. Pool 10' x 15' x 24' deep L 224 ^ W Hp0 (+0.5) 5 200 kW at 3 hr = 20.478 x 10 BTU (2.24 x 105)(0.8) =-2942 x 105 BTU

/.SZ7 5

20.478 x 10 , g , y, 7 g

-+d92 x 10 5 7* dhMr*F = F. (+1.5) A 0 C'F A I H E ,, "

'T 72 7

,o c yn yoy.c & H

c. 120*F.

Reference (s)

Tech. Specification D-1, p. 2.

- Section J continued on next page -

%.., y. , - .- .,, - - - - - -. _. ,,.__,y--.- y . , , - . .

' 24 Points Available QUESTION J.8 Briefly describe how the rabbit equipment is operated. Include in the discussion valving and motive media. (2.0)

ANSWER J.8 The operator brings the reactor to the desired power (having done a core excess check if necesservi and logs the present core excess.

The irradiation may now start.

i The rabbit operator must complete the following actions:

1. make certain that the butterfly valves venting the rabbit hood are placed in the correct position to vent the hood. These valves are found just inside the radiochem lab from the rabbit hood; the handle on the valve goes in the same direction as the valve plate.

2. Extend the security area to its outer limits (see S0P 12) and be sure that the door between the exit corridor and the console room is hooked open. 3. The large yellow sign is placed outside the door at the bottom of the stairs indicating to those coming down the stairs that a radiation field may be present. 4. The reactor operator has the completed IR. 5. A working ion chamber is placed in the "on" position and is in the rabbit hood about a foot away from the terminal. 6. Be sure that the PA system is working between the rabbit terminal and the reactor console room.

7. Obtain and be wearing your TLD badges--both whole body and ring badge. 8. Before attempting to turn the rabbit motor on, be sure to notify the reactor operator; it may be necessary to also turn on the motor switch in the reactor mechanical room.

Accspy eq; e i: Diea v,.y e.  ;, l R'I"C'('}

f a e r s.e r g >v=> + m so n- l 1

SOP-51.

l

- End of Section J -

1 w --

25 K. FUEL HANDLING AND CORE PARAMETERS (20.0)

Points Available 00ESTION K.1 During fuel handling, by what amount must the reactor be subcritical? (1.0)

a. 2.00% Delta K/K

b. 2.25% Delta K/K

c. 2.50% Delta K/K

d. 2.75% Delta K/K ANSWER K.1 b.

Reference ( s)

Tech. Specification E-2, p. 3.

QUESTION K.2 When moving a fuel element, what is the minimum water level that should be maintained over the element to provide adequate shielding? (1.0)

ANSWER K.2

- :- ft r / o FT Reference (s)

(CAF)

I 1

1

- Section K continued on next page - -

20 l

. Points Available QUESTION K.3 Explain how a control rod calibration is performed. (3.0)

ANSWER K.3

1. Establish critical conditions at 3 watts by raising the Safety and Shim Rods, leaving the Reg Rod in the core.

2. Allow the power level to stabilize for 5-7 minutes.

3. Record the rod positions as in the sample format below.

4. Withdraw Reg Rod to get a period meter reading of about

+25 - tJ' seconds and stop withdrawal .

T

5. Allow the power level to increase one full range so that the

" transient period" decays out.

6. Beginning on the 30 watt scale, use the electronic timers to measure the time it takes the power to increase by a factor of 2 (either 30% to 60% or 40% to 80%). Repeat measurement as the power increases on the 100 watt and 300 watt ranges then return the power level to 3 watts by lowering the shim Rod. Do not reposition the Reg Rod. Do not allow the power level to exceed 1 kW.

7. Record the data, average the doubling times obtained, and using the table of the IN Hour relation determine the reactivity worth of the withdrawn section of the Reg Rod.

8. Continue until the rod is fully withdrawn.

Reference (s)

SOP 33.

- Section K continued on next page -

~ __ .

', 'o 27

. Points Available 00ESTION K.4 The technical specification for the reactivity worth of a single experiment shall be less than  ?- dollars.

Fill in the blank. (1.0)

ANSWER K.4

$1.35 Fi)60 1.oo /5f oviet Reference (s)

Tech. Specification J-4a, p. 6.

QUESTION K.5 Fuel element howing will directly lead to a rapid fuel element failure. (TRUE or FALSE) (1.0)

ANSWER K.5 False. (Fuel clad will not fail with core uncovered.)

Reference (c)

Reed SAR.

- Section K continued on next page -

, - - ,, ,,, --- - - , ,- -,,-e-+--

28 Points Available QUESTION K.6 According to the REED technical specifications, fuel elements being stored shall always be arranged in a geometrical array where the k-effective is less than

? for all conditions of moderation. (Select one). (1.0)

a. 0.7

b. 0.75

c. 0.85

d. 0.8 ANSWER K.6 d.

Reference (s)

Tech. Specification H-1, p. 4.

OUESTION K.7 Draw a top view of the reactor core grid array showing the location of the: (4.0)

a. source

b. core orientation relative to the control room

c. control rod

d. rabbit in core terminus

e. shim rods

f. fission chamber

g. ion chamber

h. lazy susan ANSWER K.7 See attached.

Section K continued on next page -

p- - --- g -- -

-ye + ~ - - - - -- -

4 e

e I

l

,I .

- I~ ^~

Rwe--)1 BE /D62 _

s e

, ' /- i, 7-

\f d F/5W *  ?

K o

O b

< Al C -

x= ds/ W Y ,

/]= WM M uxp Sqm

$"=Ysd Ulf

&/det o= Eg bd E= M AO p= u ch>0 &

y l

l

. Points Available Sketch for Question B.1

• • i n J**#.e'O.e.

n -.

i.s=1stins r-13 mn. e-, o ~~ . _,... ,,, ,_

Befety c-11

~

ocG 0 hW,6h'C .

,G Cf0 M*Cs w Q oln n nsn%w w o C ny O, s n -n , nC,a n o -n +n , _ one W n O W<O W w g"ln n.n np,Cn,0U e

I ea I o g d

'%p$sgkogch9-QN OMOOO" CF V000 0

~

- Section B continued on next page -

l l

, 30 Points Available QUESTION K.8 In the event of a fuel element failure, which of the isotopes listed below will escape from the core? Indicate where they might be detected. '

NOTE: More than one answer may be correct. (1.0)

a. bromine

b. iodine C. Xenon

d. krypton ANSWER K.8

b. iodine ( Co*0"C" #'Y ##

c. xenon ( CA M , RA M

d. krypton ( c dr* , B dh)

Reference ( s)

Stephenson, R. McGraw-Hill OUESTION K.9 How does a fuel element worth change (compared to water) as the element is moved from the outer core ring toward the center of the core? (1.0)

ANSWER K.9 Increases Reference (s)

Stephenson, R., McGraw-Hill.

- Section K continued on next page -

, - ev< -- , , , , . , - ,>,

, Points Available 00ESTION K.10 Fill in the value of the rod worth. (1.5)

a. shim I 1. $

b. - z.tirn it!Actry 2. $

c reg rod 3. $

ANSWER K.10

a. $h%- N $ 4. 5 0

b. M^ n $ q . .s o

c. --W&3 n g o . So Reference (s)

Reed SAR 5.2.7, pp. 5-8.

s

- Section K continued on next page -

- - - - -" "~ - -*#~""-' '"

I n

l Points Avail able '

QUESTION K.11 Draw a plot of integral rod worth (reactivity versus TWthdrawal) for either a shim rod or reg rod. Explain the shape of the curve for 0-200% withdrawn, 20-70% with-drawn and 70-100% withdrawn. (2.5)

ANSWER K.11 1

I p [i l

/

[ l f I

,/

l I i l l I I

l l o to 70 too

'4 WITHDR AWN Because the flux is depressed in the top and bottom of the core the rod poison does not have as significant an effect as it does in the middle.

Reference (s)

Triga-Generic.

- Section K continued on next page -

. 33 Points Available 00ESTION K.12 t

When a fuel element is being moved to andfrom the core, what two (2) indications should the control room operator be observing? (2.0)

ANSWER K.12 Area Rad. Monitor Rx Power Reference (s) >

Triga-Generic.

End of Section K -

1 o

._m-- .g . g w9 -__y..,,.y.* *e- -

r r- ----et -r -*-w' --we + - m v--v*--w - --wmy ---- ' -ww '-v*- -

34

. L. ADMINISTRATIVE PROCEDURES, CONDITIONS, AND LIMITATIONS (20.0)

Points Available QUESTION L.1 Give the limitation on reactivity for experiments at the Reed Reactor. (1.0)

a. Reactivity worth of a single experiment.

b. Total absolute reactivity worth of a combination of experiments.

ANSWER L.1

a. $1.35 7' "'d T8*" **##

b. $2.00 Reference (s)

Tech. Specification 4-a and b.

QUESTION L.2 List three (3) situations during which an SRO must be physically present on the site. (3.0)

ANSWER L.2 During reactor maintenance.

During core or experimental changes.

During maintenance requiring movement of control rods.

To approve restart from unplanned or unscheduled shutdown.

wAJ/rT;-f Y Jen ,

- Section L continued on next page -

35 Points Available QUESTION L.3 Describe how the pool water low water alarm is tested. Include any notification or precautions that are required. (2.0) 1 ANSWER L.3 Notify director. Post staff member outside facility to explain

, red light. Depress plunger underneath bridge (do not bend).

Reference (s)

SOP-63.

QUESTION L.4 During the performance of special experiments, all of the follow-ing must be present at the facility. (TRUE or FALSE) (1.0) e SR0 e R0 e Reactor supervisor e Director ANSWER L.4 False.

Reference (s) e Admin. Procedure 4.2.3, p.16.

- Section L continued on next page -

l

36

. Points Available

. QUESTION L.5 Explain the procedures that must be followed in the event of:

a. A manual scram. ,

(1.0)

b. An inadvertent scram. (1.0)

c. An unexplained scram. (1.0)

ANSWER L.5 The essence of SOP-08, 8.1 for Part (a), 8.3 for Part (b) and 8.4 for Part (c) will be accepted for full credit.

Reference (s)

SP-0.8.

~

~

QUESTION L.6 Explain when and why the excess reactivity of the core must be measured. (2.0)

ANSWER L.6 Normally upon reaching (5) watts of power during startup, but '

may be variable (1-20 watts). Is done to insure adequate shut-down margin.

wr 17.nru s c.= ava PAP l Reference (s) l SOP-03.

J l

l l

1 1

1

- Section L continued on next page -

i

. 1 1

37 l

\

SCRAMS: sop 08 8.0 SCRAMS SCRAMS can be divided into two general groups: manual and

automatic. The manual SCRAMS are further divided into pre-planned and emergency response SCRAMS. The automatic SCR AMS are divided into inadvertent and unexplained SCRAMS of the various console systems such as per-cent poser or linear.

861 PRE-PLANNED MANUAL SCRAMS This action is one of the two normal ways of shutting down i

the reactor 6 While less desirable than simply driving the rods ind occasions # such as a demonstration, often call for pre-planned manual SCRANs. A manual SCRAM should be done the reactor is in the steady state mode. only when The time and action

(#aanual SCRAM") are recorded in the log book and then the SCRAM bar , is pushed doen. It is important that all 5 console contset lights are depressed simultaneously to achieve a manual SCRAM.

More on this mode of shutting down the reactor is discussed in Section T.0s 842 EMERGENCY MANUAL SCRAMS Any time an operator feels it is important to shut doan quicklye a manual SCRAM should be used.

843 INADVERTENT AUTOMATIC SCRAMS When one of the pre-set scram points has been exceeded through actions such as operator carelessness, an inadvertent

$ CRAM will ensue. There is a fine line betseen an inadvertent and unexplained SCRAM when console electronic problems such as switch noise cause the SCRAM. If it is a recurring problem that has been esil docum6nted in the recent pas t, the SCRAM may be classified as ina,dvertenti otherwise, it is an unexplained SCRAM.

All inadvertent and unexplained SCRAMS must be lo g ge d in the SCRAM 800K4 .

The time, date, operator, type of SCRAM, and full explanation of the reasons for the SCRAM are to be documented.

An SRO*S permission to restart is required. While not necessary, if the operator is an SRO and another SRO is available, it is a good idea 16 have the second SRO check and sign the SCRAM BOOK.

844 UNEXPLAINED SCRANS The name here is self-explanatory. Any une xplained SCR AM should be immediately reported to the Reactor Supervisor and/or the Directore Every effort to determine the cause of the SCRAM should be made prior to contacting the Uperations Committee prior to restarting the reactor.

At with,an inadvertent SCRAM, an unexplained SCRAM must be logged into the SCRAM BOOK.

865 RESTARTING AFTER A SCRAM OCCURRING DURING A POWER CHANGE In this situation, the purpose stamp for the power change is

not completed. A log entry of the SCRAM is made. After proper approval # a nos purpose stamp is made and the power change to the desired poser continues from the los power level pr e s en t after the SCRAM.

- Section L continued on next page -

38 Points Available 00ESTION L.7 List the responsibilities of a senior reactor operator. (3.0)

ANSWER L.7

1. Operating the reactor in accordance with the pertaining administrative and operating procedures approved by the Reactor Operations Committee and within the limitations of the appropriate Facility License and Technical Specifications.

2. Preparing the logs and records of the reactor operation.

3. Reporting all unusual conditions and events pertaining to the facility and its operation to the Reactor Supervisor.

4. The radiation safety of all personnel inside the Reactor Room during operation of the reactor, in accordance with 10 CFR 20.

5. Insertion and removal of experiments with the written approval of the Reactor Supervisor.

6. Proper shielding and storage of radioactive materials removed from the reactor, until they are turned over to a person authorized by the Reactor Supervisor to receive them.

Reference (s)

Admin. Procedures,Section II, pp. 4-5.

- Section L continued on next page -

E 39

. Points Available OUESTION L.8 List the minimum required responses in the event that an Emergency Alert is declared at the Reed facility. .

(3.0)

ANSWER L.8

1. Shut down the reactor.

2. Notify someone on the ENCL.

3. If appropriate, evacuate the facility. See Appendix C for proper procedure.

4. If appropriate, the necessary circuit breakers should be turned off. The main facility circuit breaker is on the south wall of Room 7 (across the hall from the entrance to the stockroom).

The keys to this room and circuit breaker are found in the emergency grab-bag.

5. If appropriate, notify the police. See Appendix A for emergency phone numbers.

6. In case of civil unrest, the four facility doors will be dead-bolt locked with a key located on the key ring in the mechanical room.

Reference ( s)

Reed Emergency Plan, Section IV-A.

- Section L continued on next page -

r 40 Points Available QUESTION L.9 Describe the personnel requirements for startup and operation of the Reed Reactor. Include allowable location for each individual . (2.0)

ANSWER L.9 At least two persons must be present within the Reactor Facility whenever the reactor is not shut down, as defined in the tech-nical specifications. At least one of the persons present must be a AEC-Licensed Operator. A Senior Reactor Operator must be present in the Reactor Facility (or the adjoining Chemistry Building) and the operator must know the whereabouts of this individual prior to beginning operation. All reactivity changes will be made by, or in the presence and under the direction of, an individual licensed to operate the reactor.

Reference (s)

Admin. Procedure 3.1.4, p. 9.

- End of Section L -

END OF EXAMINATION

. c EQUATION SHEET Where o g =m 2

(density)g(velocity)g(area)g =

(density)2(velocity)2 I *8I 2 2

KE = mv--

PE = agh PE +KE +P y' where V = specific 2

1 1 1 l = PE +KE 2 +P2 V22 volume P = Pressure Q = acp(To u t -T9 ,) Q = UA (T,,,-Tsta) 0 = m(h .h2 I g

P = P,10(SUR)(t) p , p ,t/T SUR = 26.06 T= 1/ Delta k T

' delta K = (K,ff-1)/K,ff CRg(1-K,ffg) = CR 2 II'Eeff2) CR = S/(1-K,ff)

M= (1.K,ffg) SDM =

(1-K,gf) x 100%

II~E eff2I K eff decay constant = =

in (2) 0.693 A g = A,e-(decay constant)x(t)

I I I/2 I/2 Water Parameters Miscellaneous Conversions .

I gallon = 8.345 lbs 1 Curie = 3.7 x 10 10 q,,

1 gallon = 3.78 11ters 1 kg = 2.21 lbs 1 ft3 = 7.48 gallons 1 hp = 2.54 x 10 3 Otu/hr Density = 62.4 lbm/ft 3 1 MW = 3.41 x 10 6 8tu/hr Density = 1 ge/cm 3 1 Stu = 778 ft-1bf Heat of Vaporization = 970 Otu/1be Degrees F= (1.8 x Degrees C) + 32 Heat of Fusion = 144 Otu/lba 1 inch = 2.54 centimeters 1 Atm = 14. 7 ps ia = 29. 9 in Hg g = 32.174 ft-1bm/1bf-sec 2 e

8 i,

4 i A.

% .U.S. NUCLEAR REGULATORY COMMISSION REACTOR OPERATOR LICENSE EXAMINATION Facility: REED COLLEGE ___

Reactor Type

TRIGA Date Administered: MAY 14, 1985 Examiner: SMITH /UPTON i Candidate: ANSWER KEY tv! A 5 rER INSTRUCTIONS TO CANDIDATE:

Use separate paper for the answers. Write answers on one side only.

Staple question sheet on top of the answer sheet. Points for each question are indicated in parenthesis after the question. The passing grade requires at least 70% in each category and a final grade of at least 80%. Examination papers will be picked up six (6) hours after the exemination starts.

Category  % of Candidate's  % of Value Total Score Cat. Value Category 14 14 A. Principles of Reactor Power

, Operation 16 16 B. Features of Facility Design 14 14 C. General Operating Characteristics 14 14 D. Instruments and Controls l 14 14 E. Safety and Emergency Systems 1

14 14 F. Standard and Emergency Operating Procedures 14 14 G. Radiation Control and Safety 100 TOTALS Final Grade  %

All work done on this examination is my own; I have neither given nor received aid.

Applicant's Signature ~

i

I , ,

. l 1

A .

c A. PRINCIPLES OF REACTOR OPERATION (14.0)

Points 1 Available l QUESTION A.1 Specify the letter designation of the most correct statement from those listed below. (1.0) ,

1 (a.) The energy spectrum of neutrons obtained from the fissioning of U-235 atoms follows a Maxwell-Bottgmon distribution.

(b.) The energy spectrum of neutrons obtained from the thermal-neutron fissioning of U-235 atoms is narrowly peaked in the range of 4 MeV.

(c.) The energy spectrum of neutrons obtained from the fissioning of U-235 atoms contains two peaks, the thermal-neutron peak and the fast-neutron peak.

(d.) Thermal neutrons have an energy spectrum with a peak at 0.025 eV for a reactor at room temperature.

ANSWER A.1 (d.). (+1.0) l Reference (s)

! 1. Reed: Reed Training Document, Technical Education Research l Center-Southwest, " Nuclear Technology," pp.12-1-13 to 12-1.18.

l

- Section A continued on next page -

_ _ _ _ _ _ _ - - - - -a ---- -____

2 b

^

Points Available QUESTION A.2

a. If the Reed Triga Reactor were increasing power with a period of 25 sec, how much time is required for the power level to increase by'2 decades? Show your calculational procedures. (2.0)

b. If the mean lifetime of neutrons in the reactor were 8 x 10-2 sec, what is the reactivity of the core? (1.0)

ANSWER A.2

a. T = 25 sec P/Pn = 100 = et/25 (+1.0) in 100 = t/25 t = 25 in 100

= 115 sec (+1.0)

= 1.92 min

b. T = f/ak (+0.5) ak = t/T

, 8 x 10-2 sec 25 sec

= 3.2 x 10-3

! Reference (s)

1. Reed: Reed training Document, Technical Education Research Center-Southwest, " Nuclear Technology," pp.12-1-13 to 12-1-18.

- Section A continued on next page -

l l

t

3 s

. Points Avail able QUESTION A.3 Consider the " doppler broading" effect that takes place in the fuel of the Triga Reactor.

-a. Describe the phenomena of doppler broading. (1.0)

b. As the temperature of the fuel increases what impact does this phenomena have on Keft? What parameter of the six-factor fonnula is predominantly affected? (1.0)

c. Does this phenomena in the Triga reactor lead to a positive or negative temperature coefficient and is the temperature coefficient considered a " slow (delayed)" or " fast (prompt)"

coefficient? (1.0)

ANSWER A.3

a. An increase in the fuel temperature causes a broadening of the neutron absorption peaks (the resonance peaks); on graph of neutron absorption cross-section as a function of energy the cross-section peaks widening (and become lower in (mag-nitude). (+0.5) The broadening is due to the increased vibra-tional energy as the temperature increases. (+0.5) The peaks in the absorption cross-sections of U-235 and U-238 are the primary contributors to the effect in the Triga Reactor. (+0.5) 4 (1.0 max)

b. As the fuel temperature increases, the widening of the resonance peaks causes the resonance escape probability (+0.5) to decrease and hence for Keff to decrease. (+0.5)

c. The fuel temperature coefficient is a negative temperature coefficient (+0.5) and is considered a prompt coefficient.

(+0.5)

Reference ( s) ,

Reed: Reed training Document, Technical Education Research Center-Southwest, " Nuclear Technology," pp.12-7-8 to 12-1-9.

- Section A continued on next page - -

., o, 4

, Points Avail able

,e QUESTION A.4 s, , ' .,

e' ' A nuclear reactor has a shutdown margin of 7% ak/k and a neu-tron detector is recording 20 cpm. What will this detector read when Keff = 0.88 and 0.997 (2.0)

,e i

ANSWER A.4 ak -

k i = 0.07 1

1-k 1 k

= 0.07 ,

1 1=kl + 0.07 kg 1 = 1.07 k i ki = 1/1.07 = 0.93 (+0.5) 1-k CR 1-k i=y 2

i (M.5) 1 8 2 1 CR2 = (20)05EEE) (o.f61)

= mm:ps / / . 7 0 #^ (+0.5)

CR 0.07 3 TDT " W i

CR3 = 140 cpm (+0.5)

Reference (s)

.r'

1. Generic: " Academic Program for Nuclear Power Plant Personnel,"

Yolume II, pp. 5-6 through 5-13, General Physics Corporation.

- Section A continued on next page -

> i;' ,i

. *L_.' -_- - -- -

5

, Points Available QUESTION A.5 Why is the worth of a control rod dependent on the position of that control rod? (1.0)

ANSWER A.5 The reactivity effect, i.e. worth, of a control rod depends on the impact that the material of the control rod has on the absorp-tion rate of neutrons (assuming a poison-type of control rod).

The reactivity worth of a small-sized absorber can be expressed as dependent on the (relative) neutron flux in the vicinity of the absorber and the impact that a change in that location will have on the total neutron population. Mathematically, the result is that the effect is proportional to the square of the neutron flux at the location where the change is made in absorber con-centration. Hence, changing the amount of absorber material near the center of the reactor core will have the largest effect on reactivi ty. (+1.0)

Reference (s)

1. GA Technologies.

- Section A continued on next page -

• • ]

6 l

, 1 l

I

, Points  !

Available QUESTION A.6 i List the letter designations of all those statements given below  ;

that are correct statements. (2.0)

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

(b.) The thennal-neutron microscopic absorption cross section of Xe-135 is greater than 10 6 barns.

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

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

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

ANSWER A.6 The correct statements correspond to designations (a.), (b.) (c.)

and (e.). [0.5 each, -0.5 for (d.)]

Reference ( s)

1. Generic: Academic Program for Nuclear Power Plant Person-nel, Volume II, General Physics Operation, pp. 4-144f.

2. GA Technologies: Syllabus and Triga Training Manual, GA Technologies, Inc., pp. 6-25.

3. Reed: Reed Training Document, Technical Education Research Center-Southwest, " Nuclear. Technology," pp.12-7-12f.

Section A continued on next page -

- s, - = w

7

, Points Avail able QUESTION A.7 Numerically estimate the reactivity change in T which occurs in the Triga reactor core if the water temperature is maintained constant and the fuel temperature is raised 30*C. (1.0)

ANSWER A.7 af r 10-4 /*C (+0.3)

[ = (10-4)(30) (+0.3)

S=3 00 (+0.5)

=43f.

Reference (s)

1. GA Technologies: Syllabus and Triga Training Manual, GA Technclogies, Inc., pp. 6-17f.

2. University of Arizona: "

General Infomation on the University of Arizona Triga Reactor," NE 420, p.1.

Section A continued on next page -

, -----.v.- , . - - . g .- - -w-- y , -- -

,-r -

8

. Points Available QUESTION A.8 Choose, by specifying a letter designation, the most correct sta'tement from those given below. (1.0)

(a.) The unit (of measure) of the " barn" is a measure for the macroscopic neutron cross section.

(b.) Delayed neutrons have at birth a harder energy spectrum than neutrons produced from fissioning by thermal neutrons.

(c.) The microscopic cross-section for neutron interaction with a given material is a function of the isotopic composition of the material and of the energy of the neutron.

(d.) The reactor rate for neutron absorption in a given material follows a "1/(neutron flux)" variation.

ANSWER A.8 (c.).- (+1.0)

Reference (s)

1. Generic: " Academic Program for Nuclear Power Plant Person-nel," Volume I, General Physics Corporation, pp. 4-25f.

- End of Section A -

e

9 B. FEATURES OF FACILITY DESIGN (14.0)

Points Available OUESTION B.1 Draw a sketch of a view looking down on the core showing fuel element addresses and the location of shim, safety and regulating rod. (3.0)

ANSWER B.1 See attached sketch.

Reference (s)

Reed SAR.

- Section B continued on next page -

wwa- -

w--m -w w w ,+ w -~+r----w----4 wwrw2-< --

y - - -v q- we-<-s- n- ,

~ e. i

\

&?$ -

gy hD /h

!np.

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o y .- 4 -c ty ORAMffrE D.EMEN T _

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x -

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CJJ'**

sounct tt.tMant

10

, Points Available Sketch for Question B.1 arm:r c=:i.:- -

===-

Regulating E-13

,g c ;, o --. --. .- ~ .

O ,mQ O"O

~

, M6 ,

k.,U o I-Otej O

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hog ggo '

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- Section B continued on next page -

11

• Points Available 00ESTION B.2 Which one of the following statements about the Rabbit System is correct? (1.0)

a. This system is used to convey the Rabbit to a central core location of maximum flux.

b. There is no contact with the reactor coolant; therefore, flooding is impossible.

c. The Rabbit is a hollow plastic cylinder containing about 50 g of cadmium to insure it will never insert positive reactivity.

d. Argon gas is used to operate the Rabbit in order to minimize corrosion in the tube.

ANSWER B.2 b.

Reference (s)

S0P-51.

l l

l l

4 1

- Section B continued on next page -

l l

l l

12

. Points Avail able QUESTION B.3 A portion of the oxygen in the pool water is activated to nitrogen-16 by a fast neutron reaction as the water passes upward through the core. What design feature helps reduce the dose rate at the top of the pool from N-16? (2.0)

ANSWER B.3 Downward slanted discharge of water into the tank through a diffuser nozzle.

Reference (s)

Reed SAR, pp. 7-8.

- Section B continued on next page -

~

L

13

,. Points Available OUESTION B.4 The Reed Reactor Ventilation System is shown in the figure attached.

List the position (status) only of dampers 10, 11, 12, 13, 14, 15,

, 16 and 17 during isolation operation. (3.0)

ANSWER B.4 See attached figure.

(0.4 ea) (3.0 max)

Reference ( s)

SAR, pp. 4-7.

i t

h l

- Section B continued on next page -

i

14

, Points Available Figure for Question B.4 i "" *DL* ,  ; To Exisrius L A

• o m A ro se v l (Igj s .Ew.HaosT sysres.

! t Y@ t 70 -

l 9

{* v d ,

qs.

h M 'eMa

?$ E ~p~ C _

a r c ^

w@

a _

r  ;

.PLnN vm l .

h hh A Yq '"" -

A. Supew UwiT REACTOR Room --

' B- ExsAusT Uwir Re AcTom Room

+%' " #l - -@

C - SUPPt Y UNy-CouTacL4 MECH.RocM h h D A n s o n. u T E. Fli T E.R /**

hl:

o

~

6

. 5CH E M ATic Ana systems a 3

Raao REACTOR

~  %. .> ,

cuss ,.-./

Svu e.o ts ' AUS> ,qs-)

Supp ty R EToct us O  ; , e_

REAcTom Roou REAcTom Room -_

Re.Ac p Re o M Mec u. Room e ,

Cc4720L RoeM COMTh Room Mach. Room OUTsion Assa fura 845.

EXHAUST stack-

• NORMAL HEATING & VENTILATING CYCLE Section B continued on next page -

9 m-,. +.,--------w-7.-----.% ._%,-y+---..c-,,.-,v.- + , - , - - - - __._ _

~ i J

15 Points Available Figure for Answer B.4 ca.s e g g-ToExHeJtT Emmv a S u v1.Te s 1.a me M = 4 to sa t l @ { l 8

b i b@ '

@~ l

'@ t @ E ---.

@ \

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I- l .PLauu 4 (h Fern oorsos v Asia.

A- SUPPLY UNIT REAcTom QooM.

A

-== [ @

l b F.xuAust vuiT usAcroa ecoM l f- Su PPcy vulT- CouTaos.1Macu. Room seau

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RETu8s M S D ---.-

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) REACToE Qocu Mach. Roou . _

~

CouTuoi Roou j C;ouTuoi. Room Mac H. ' RocM OUT%tos Aim luTAws. -. k Tir=HT CLossuc, TYPE DAMPEES

. E.% H AUST STACW. - x Moovi.Artus DAMPsirs.

s.

ISOLATION OPERATING CYCLE SuppLv user A suur oown, sweetr user C Amo exwaust ram B openArimo oAnern (18) cLosto to LAsonArony AntA. oAnecas (10) (11) (15) (17),

cLosto. Danetas (12) (14) (15) (1 o p t ri . 150 cFM or Ain tanAusrto runousu attuaw salLLt 5, aanetas 4)(15) opta Amo resor oato to allow ALL or rues sawaust Aan rnon RcAeron noon to so runousM rut AssoLurt riLrta D, oAMPtn(1$) PAntlALLv oPtM to PLENun to nAME uP rutL cAPActry or EswAust user B Ano sawaustoms rumouen sawAust stacu

9. A steemt assArtva Patssunt as so et nA:NrAINeo IN REAcron moon. ALL oAnetas Ant or rNE PosltlVs sNur-orr tvPt ANo Ant to et oPenArto or encugArge oAneta openArons.

Section B continued on next page -

16 Points Available QUESTION B.5 Explain how the pool water is prevented from mixing with the secondary water during reactor operation if a leak should occur in the heat exchanger. , (2.0)

ANSWER B.5 Secondary side is maintained at higher pressure during operation.

Reference ( s)

SAR 5.2.6.

- Section B continued on next page -

17 Points Available QUESTION B.6 List the five (5) functions of the Reactor Cooling and Purifi-cation System. (3.0)

ANSWER B.6

1. Maintains low conductivity of the water to minimize corrosion of all reactor components, particularly the fuel elements.

2. Reduces radioactivity in the water by removing nearly all particulate and soluble impurities.

3. Maintains the optical clarity of the water.

4. Provides a means of dissipating the heat generated in the reactor.

5. Reduces the radiation level due to nitrogen-16 at the top of the reactor because the vertical convective core water cur-rents are deflected by the downward slanted discharge of water through a diffuser nozzle on the water system tank inlet. (+0.6 ea)

Reference (s)

Reed SAR 5.2.6, pp. 5-7.

4

- Section B continued on next page -

,- - , ,.r- .,-. - , , - , - - - , . _ , - - - - - - , . ,.

18

• Points Available QUESTION B.7 i

- Explain the purpose of the graphite plugs at the top and bottom of the fuel-moderator elements. (2.0) 4 ANSWER B.7 Provide top and bottom reflector for each element.

Reference (s)

Reed SAR 5.2.2.

End of Section B -

t e

- -- , , , . . - . ,-u+ - -rv ---e, , -,-e<~ - - - -- ,w- ,-,-c-+- -.-4e.w~--w we%.anw s-,- -w--=-y- wv- -

w- r-- y

19

. C. GENERAL OPERATING CHARACTERISTICS (14.0)

Points Available OUESTION C.1 After a long period of full power operation a scram occurs.

a. What would you expect to see while monitoring the nuclear instrumentation for the first five (5) minutes? Explain. (2.0)

b. What difficulties would you expect associated with a reactor startup eight (8) to twelve (12) hours after the scram?

Explain. (2.0)

ANSWER C.1

~

a. Prompt drop followed by an -80 second negative period.

b. Xenon will peak, then decay adding positive reactivity over the next sixty (60) to seventy (70) hours.

Reference (s)

Stephenson, R., McGraw Hill.

- Section C continued on next page -

20 Points Available QUESTION C.2 If the Reed Reactor is critical at one (1) watt and power is increasing on a constant ten (10) second period, how long will it take the reactor to reach a power level of four-hundred (400) watts? Show work. (2.0)

ANSWER C.2 t

P(final) = P(initial) e / TAU TAU = 10 Sec (400) =-(1 watt) e / tTAU in 400 = t/10 see t = 10 in 400 t = 10 x 5.99

= 59.9 seconds Reference (s)

Stephenson, R. , McGraw-Hill .

- Section C continued on next page - ,

.e I[

21

, Points Available QUESTION C.3 What is the maximum excess reactivity allowed by the Reed Operat-ing License (including) experiments. (1.5)

ANSWER C.3 2.25% ak/k ($3.00)

Reference (s)

Reed SAR, p. 1-1.

QUESTION C.4 What is the maximum steady state thermal power level allowable by the technical specifications? (1.5)

ANSWER C.4 250 kW.

Reference ( s)

~

Reed SAR, p. 1-1.

- Section C continued on next page -

-,-,c-, , - - -, --~n,.,,, - , ,w, w-,.,-- w,- -~ ,, , -,- - -- .r , ,

-w -...- ,--, , _

22

. Points Available QUESTION C.5 The regulating rod is worth about (1.0)

a. $2.73

b. $3.73

c. $1.33

d. $1.73.

ANSWER C.5 d.

Reference (s)

Reed SAR 5.2.7, p. 5-8.

QUESTION C.6 i If the reactivity addition rate of a regulating rod is adjusted as per the technical specifications, how long would it take to insert one (1) dollars worth (-0.7% ak/k) of reactivity? Select i one. (1.0)

a. 5 seconds

b. 7 seconds I c. 15 seconds

d. 1 minute I

ANSWER C.6 C hd*K L OS N ##

b. Accifr -

v1C 007 CA 0025 FGA $

Reference ( s)

Reed SAR 5.2.7, p. 5-8.

- Section C continued on next page -

23

- Points Available QUESTION C.7 Describe the LAZY SUSAN system. Include in the discussion how specimens are loaded and unloaded. (3.0)

ANSWER C.7 A rotary specimen rack, located in a well in the top of the graphite reflector, provides for the large-scale production of radioisotopes and for the activation and irradiation of small (+1.0) specimens in a dry atmosphere. All 40 positions in this rack are exposed to neutron fluxes of comparable intensity. Samples are loaded from the top of the reactor through a water-tight tube into the rotary rack using a specimen lif ting device (essen- (+1.0) tially a fishing pole with a grapple mechanism on the end of a power cor6). [The rotary rack can be turned manually or by using a motor drive at the top of the reactor.] [+1.0]

Reference (s) JW mMg WBO 8P N eh "C Reed SAR 5.2.5, pp. 5-5/7.

- End of Section C -

24 D. INSTRUMENTS AND CONTROLS (14.0)

Points Available OUESTION D.1 Explain the functions of the upper and lower limit . switches on each of the rod assemblies. (3.0)

ANSWER D.1 Show:

1. When magnet is in up position.

2. When magnet is in down position.

3. When magnet is in contact with control rod armature.

Limit upper and lower travel.

Reference (s)

Reed SAR 5.2.8, pp. 5-11.

QUESTION D.2 Explain what type of detector is used for the count-rate channel. (1.0)

ANSWER D.2 Fission chamber.

Reference (s)

Reed SAR 5.3.2, pp. 5-14.

- Section D continued on next page -

25 Points Available QUESTION D.3

a. How and why is gamma radiation compensated for in a compen-sated ion chamber (CIC)? (3.0)

b. How would the output of a CIC be affected if it was sig-nificantly under-compensated? (2.0)

ANSWER D.3

a. Neutron countrate is sensed in the outer can by interaction with boron paint. Gamma radiation is sensed in both the outer can and inner can. The lack of boron paint in the inner can causes only gamma interations to take place. A compensating voltage is applied to the inner can to exactly balance the ganna. current being sensed in the outer can:

l g ar I -r l

m

! b. At low powers and for extended periodt after shutdown, the i

detector output would read high. At JeN p6wers the effect would not be noticeable because the gamma flux is propor-l tional to power and is overwhelmed by the neutron flux. -

Reference (s)

G. A. Triga Training Manual 2.5.2, pp. 2-39/40.

l

- Section D continued on next page -

9 l

26

, Points Available OVESTION D.4 List six (6) functions that scram the reactor. (3.0)

ANSWER D.4

1. Power level channel, compensated ion chamber, micromicroammeter.

2. Power level channel, ion chamber, adjustable by operator, from 20 to 110% of full power.

3. Reactor period channel, adjustable period scram between = and

+3 sec.

4. Manual.

5. Ion-chamber power supply failure.

6. Console power circuit failure.

Reference (s)

Reed SAR 5.3.4, pp. 5-16.

Section D continued on next page -

-.m..-a e--re- ' ' ~ ~ -='- - *--* PN* - --rs- - - - --* - - - - - -

tr--w- v- -'-~+-w'e < --v v4 w --7-*-*Tr~a---ss.--- a'-

27

, Points Available OUESTION D.5 Describe the control rod inhibits at the reed reactor. (2.0)

ANSWER D.5 Interlocks are provided to:

1. Assure minimum source strength before control rods can be withdrawn.

2. Prevent withdrawal of two control rods simultaneously on manual control.

Reference ( s)

Reed SAR 5.3.4, pp. 5-16.

- End of Section D -

28 E. SAFETY AND EMERGENCY SYSTEMS (14.0)

QUESTION E.1 List the location of the buttons for. manually activating the evacuation alarm. (2.0)

ANSWER E.1 One each in the Reactor Room and the Console Room.

Reference ( s)

1. Reed Emergency Plan, p. 2.

QUESTION E.2 Answer the following TRUE or FALSE. An amber failsafe light and a red alarm light for the continuous air monitor are located on the cam and on the console. (0.5)

ANSWER E.2 Fal se.

Reference ( s)

1. Reed Emergency Plan, p. 2.

a

- Section E continued on next page - ,

29

, Points Available OUESTION E.3 The following statement is from the Tech-Specs. "The reactor ,

with fixed experiments in place, shall be considered to be shut-down (not in operation) whenever all of the following con-ditions have been met: (a) ...; (b) ...; (c) ..." Provide these three (3) conditions. (3.0)

ANSWER E.3

"(a) the console key switch is in the "off" position and the key is removed from the console and under the control of a licensed operator (or stored in a locked storage area);

(b) sufficient control rods are inserted so as to assure the reactor is subcritical by a margin greater than 0.7%

ak/k cold, without xenon; (c) no work is in progress involving fuel handling or refueling operations or maintenance of its control mechanisms."

(+1.0 each)

Reference (s)

1. Reed: Technical Specifications for, the Reed College Triga ,

Mark I Reactor, July 2,1968, p.1.

- Section E continued on next page - ,

~

n v

30

. Points Available OUESTION E.4 Provide a description of the operation of the following instruments.

a. Pencil dosimeter

b. Film badge

c. Cutie pie Specify the type of radiation for which each instrument is designed to monitor-- (3.0)

ANSWER E.4

a. The pocket dosimeter used at the Reed Reactor Facility is direct reading and operates on the principle of the gold-leaf electroscope. The detection system consists of a small quartz-fiber electroscope, which forms part of the collecting elec-trode. The instrument case, which is insulated from the fiber system, serves as the other electrode. The collection volume is small (2 cm3) and most often contains air at ambient pressure. The quartz fiber is displaced electrostatically by charging it to a potential of about 200 volts. By adjusting the voltage on the charger, we can bring the image to zero-scale reading. The scale may be measured in tenns of image movement. The light for viewing enters through a window at the end of the device. An image of the fiber is focused on the scale and is viewed through a lens at the other end of the instrument. Exposure of the dosimeter to radiation dis-charges the fiber, thereby allowing it to return to its original position. The amount discharged, and consequently the change in position of the fiber, is proportional to the radiation exposure. (Commonly-used direct reading dosimeters that are commercially availably have a range of 0-200 mR, and read within about 15% of the true exposure for gamma-ray energies from about 50 kev to 2 MeV.) (+1.0)

- Question E.4 continued on next page -

0 ,

31

.. Points

'q Available

b. Film badge dosimetry is based on the fact that ionizing radia.

j tion exposes the silver halide in the photographic emulsion, which results in a darkening of the film. The degree of

/ darkening, which is called the optical density of the film, can -

be precisely measured with a photoelectric densitometer whose reading is expressed as the logarithm of the intensity of the light transmitted through the film. A typical film badge

, / consists of a packet of dental-sized film wrapped in light-tight paper and worn in a suitable plastic or metal container.

The film for X and gamma-radiation includes a sensitive emulsion and a relative insensitive emulsion. Such a film pack is useful over an exposure range of about 10 mR to about

, 1800 R of gama rays. The film is also sensitive to beta-radiation if the beta energy exceeds 400 kev. (+1.0)

c. For beta and gamma radiation levels of between 5 mrem /hr and ,

l 500 mrem /hr, ionization chambers are generally used for both l detection and measurement. A conmonly used instrument is called the cutie pie meter. An ionization chamber is a gas-filled detector that is operating in the Ionization Region.

Such detectors are accurate but low in sensitivity. (+1.0)

, Reference ( s)

1. Reed: Reed Training Document, Technical Education Research Center-Southwest, " Nuclear Technology," pp. 2-38f.

a j

- Section E continued on next page -

_ _ _ _ m____ _ _ - - - - - - -

32

, Points Available QUESTION E.5 Specify the letter designation of the most correct statement from those listed below. ,

I (a.) Maintenance work cannot be carried out on more than two rods I at a time.

(b.) The core excess shall be measured and recorded in the Log Book after any change which might affect reactivity.

(c.) All unexplained scrams must be reported to a Senior Reactor Operator.

(d.) The pressure of the lake water in the secondary water sys-tem of the heat exchanger must at all times be less than the pressure of the reactor pool water in the heat exchanger.

ANSWER E.5 (b.). (+1.0)

Reference ( s)

1. Reed College Reactor Facility, Administrative Procedures, pp. 2-74f.

Section E continued on next page -

I -

..g. . . ,

33

. . Points Available QUESTION E.6

a. What two (2) conditions will automatically isolate the ven-tilation systems? (2.0)

b. On isolation, which of the following will occur?

1. Fan A starts, damper 13 and 14 close

2. Fan A shuts down, damper 11 and 15 open

3. Fan A starts, damper 13 and 11 close

4. Fan A shuts down, damper 13 and 11 close (1.0)

ANSWER E.6

a. (1.) The radioactivity in the control room exceeds the alarm setpoint of the CAM. (2.) The radioactivity of the air purged through the exhaust stack of the ventilation system exceeds the trip point of the gaseous stack monitor.

b. #4.

Reference ( s)

1. Reed: Reed SOP - 65.1, 65.5.

Section E continued on next page -

3 -, y *7 ---

-y-y--g-- , ,,, , --, - - - - --

m 34 Points Available QUESTION E.7 The reactor cannot be operated if the compressor is not operable.

Why? (1.5)

ANSWER E.7 A low line pressure can render the dampers useless which put the ventilation system in isolation.

Reference (s)

1. Reed: Reed S0P 1.5.

End of Section E -

-->-4 -v -- , , - - - - - , - - - - - - - - y n ,

35 F. STANDARD AND EMERGENCY OPERATING PROCEDURES (14.0)

Points Available QUESTION F.1 List six (6) of the eight (8) Reed facility emergency signals and alarms, their location and their meaning. (3.0)

Example Name Location Meaning of Alarm

1. Security alarm Bell on south wall of Possible illegal entry Reactor Room into the facility ANSWER F.1 EMERGENCY SIGNALS AND ALARMS Name Location Meaning of Alarm

1. Radiation Area NW corner of pool Source of high radiation Monitor (RAM) near the reactor pool

2. Continuous Air East side of reactor Air above pool contains Monitor (CAM) room excessive amount of enactivity

3. Stack Monitors Console room Air leaving the reactor Gaseous room contains excessive Particulate radioactivity 47k' Low Water Alarm Lights in west hall Water in pool has dropped and on roof 4 in. below normal

5. Evacuate Alarm Siren in reactor room Manually operated from Light in Radiochem Lab console or reactor room

6. Security Alarm Bell on south wall of Possible illegal entry reactor room into the facility

7. Secondary Water High-pitched alarm Secondary water pressure in reactor room is low, pump is on

8. Secondary Water Green light on south Not an alarm; may be on Pump Motor wall of reactor room or off Reference (s)

Reed Emergency Plan.

- Section F continued on next page -

36 -

. Points Available QUESTION F.2 Information associated with wipe tests is to be recorded in the Health Physics Log Book in a five-column format. List the headings of these five (5) columns. (2.5)

ANSWER F.2

1. Wipe position

2. Count length (min)

3. Counts

4. Gross CPM

5. Contaminated?

Reference (s) .

SOP-02.

QUESTION F.3 Explain why it is required that the reactor control be placed in the automatic mode when reactor power is greater than 90%. (2.0) s ANSWER F.3 Because of frequent and unexpected power fluctuations.

Reference ( s)

SOP-04.

l l

l

- Section F continued on next page - ~

l 1

l

37 Points Available QUESTION F.4 List three (3) of the five (5) conditions that would be considered to be major contamination. (3.0)

ANSWER F.4

1. Any area showing a greater than 1000 times background count rate when a wipe test is taken.

2. The rupture of a fuel element.

3. Any accident involving unsealed sources of alpha particles.

4. The venting or rupturing of an experiment involving fission products.

5. Any contamination requiring notification of the NRC. this includes contamination which

a. results in the release of radioactive material in excess of the standards set forth in Appendix B of 10 CFR 20

b. results in the loss of one working day to the facility

c. results in damage to the facility of greater than $2000.

Reference ( s)

SOP-19, p.~19.9.

- Section F continued on next page -

33 Points Available OUESTION F.5 The problem log is maintained in a three-column format. Expl ain what information is contained in these three (3) columns. (1.5)

ANSWER F.5

a. Date

b. Problem description

c. Page number indicating location of detailed information Reference (s)

SOP-11.

QUESTION F.6 Explain how rod drop time is measured. (2.0)

ANSWER F.6 This is a visual test of the rod drop times. One operator remains at the console while two other timers position them-selves in the console room so that they can see the control rod lights. The operator raises one, and only one, rod to its maximum height. The other two control rods are to remain fully inserted into the core. The console operator then manuall,y i scrams the rod; the timers start their watches when the yellow l magnet goes off and stop their watches when the blue " cont"

! light goes off. The yellow light indicates that the rod has been released, the blue " cont" light indicates when the rod down switch has been closed indicating that the rod is fully back into the core. The times for each rod should be averaged.

l Then the procedure should be repeated for the other two rods, l one at a time.

1 I

Reference (s) l

! SOP-42.

l - End of Section F -

1

39

. G. RADIATION CONTROL AND SAFETY (14.0)

Points Available OUESTION G.1 A target has been irradiated in the Triga Reactor in the Lazy Susan.

a. You anticipate that the target contains only one stable iso-tope of one low-Z element that has undergone a neutron absorp-tion [an (n,y) reaction]; you anticipate that the radioactive decay of the resulting radioactive isotope is a one-step decay to a new stable isotope. What type (s) of emissions would you anticipate would come from the radioactive target after it is removed from the reactor? Justify your answer. (2.0)

b. If, after you have removed the target from the reactor, you record over a period of time the countrate from from a detector placed next to this target, how would you determine the half-life of the radioactivity. (2.0)

ANSWER G.1

a. If a stable isotope of an element absorbs a neutron, it will fonn a new isotope that is above the line of stability. (+1.0)

Isotopes of low-Z materials whic5 are above this "line" usually decay toward the "line" by S emission. Such 8 emissions may be preceded by or may include the emission of one or sev-eral y s. (+1.0)

- Answer G-1 continued on next page - ,

40

, Points Available

b. The radioactive decay of a single radioactive isotope will follow the exponential decay law.

A 1=Ae~Ab g (+0.5)

A2=Ae-Ah g

^1, ,-A( ti2-t )

2 in A1 - in A2 = -A(ty -t2 I A* in A1 - in A2

(+2.0) g_g then, 1/2 * .693 A

Graphically, you can plot in A(t) versus t and the slope of the graph is -A. (+2.0)

(+2.0 max)

Reference (s)

1. Reed: Reed Training Document, Technical Education Research Center-Southwest, pp.1-7 to 1-12.

- Section G continued on next page - -

l L

41 l l

l

. Points Available QUESTION G.2 If the target of Question G.1 had been placed in the Triga Reactor ,

and the reactor brought to 100% of full power, sketch the activity 1 of the target as a function of time. (2.0) 4 ANSWER G.2 a

in et.

A = Ie(1-gat) b

(+2.0 for shape or equation)

Reference (s)

1. Reed: Reed Training Document, Techn,1 cal Education Researen Center-Southwest, pp. 1-15.

- Section G continued on next page -

- - - , . - - ,ey --

.,-m, ,,- - , __- - -- -- , -- . - - -, - -n,, - - , -p e ,-

42

, Points Available QUESTION G.3 If the target of Question G.1 had produced the following:

• a single radioactive isotope from the (n,A) reaction

• a half-life for the n-produced isotope of 10 min e a radioactive daughter from the n-produced isotope e a half-life for the daughter of 10-hr, then, after the target is taken out of the reactor, how does the concentration of daughter atoms vary with time? (2.0)

ANSWER G.3 The situation within this target is essentially the same as that of Xe-135 concentration within the reactor after a trip. Hence a

hay $ba

• A f.mr i

l ,

i I I

--De i6 &

s >

"f,,',[ t A .- s

(+2.0 for shape) .

Reference (s)

1. Reed: Reed Training Document, Technical Education Research Center-Southwest, pp. 1-12, 12-7-22, 23, 24, 25.

(

l l

' - Section G continued on next page - .

43

, Points Available 00ESTION G.4 If two centimeters of lead placed at a certain location in a beam of gamma rays would reduce the gamma radiation level from 100 mR/hr ~

to 50 mR/hr, what thickness of lead placed in this beam would reduce the gamma radiation level from

a. 400 mR/hr to 50 mR/hr (0.5)

b. 50 mR/hr to 25 mR/hr? (0.5)

ANSWER G.4

a. 6 cm (+0.5)

b. 2 cm (+0.5)

Reference (s)

Reed: Reed Training Document, Technical Education Research Center-Southwest, pp. 1-24, 1-25, 2-1, 2-2.

QUESTION G.5 If the gamma-ray radiation level from a pump (point source) had been 30 mR/hr 1 foot from the pump, what would be the radiation level 10 feet from the pump? (1.0)

ANSWER G.5 Neglecting gamma-ray absorption by the air, 1

distance factor = (f)2

= (+0.5) rad level (10) = rad level (1)/100

= 0.30 mR/hr. (+0.5) i Reference (s) l 1. Generic: Nuclear Energy Training, Module 5, " Radiation l Protection," pp. 3.3-1 to 3.3-4.

- Section G continued on next page -

l

44

. Points Available 00ESTION G.6 If a man had been exposed to 0.01 R gamma radiation, 0.04 rad of be'ta radiation and 0.02 rad of fast neutrons, what is

- his total biological dose in rems? Show your work. (2.0)

ANSWER G.6 0.01 R of gamma x 1 QF = 0.01 rem 0.04 rad of beta x 1 QF = 0.04 rem 0.02 rad of fast react x 10 QF = 0.20 rem Total dose = 0.25 rem

(+0.25 for dose equation, +2.0 for ans-7r, +2.0 max)

Reference ( s)

1. Generic: Nuclear Energy Training, Module 5, " Radiation Pro-tection," pp. 2.1-1 to 2.1-3.

2. Reed: Reed Training Document, Technical Education Research Center-Southwest, pp. 2-3.

QUESTION G.07 Explain the procedures to be used at the Reed Triga facility to prepare radioactive material for shipment. (2.0)

ANSWER G.7 The essence of SOP-52 (Radioactive Materials Transfer) will be accepted for an answer. (+2.0)

Refere..e(s)

1. Reed: SOP-52, " Radioactive Materials Transfer."

- Section G continued on next page - ,

45

&7. RADIDACTIVE MATERIALS TRANSFEtt soc 52 5261 PURPOSE:

To cosply eith Federal and State regulations recuiring RRF to keep track of all radioactive matorisis leaving the rea:-

tor facility such as irradiated samples, produced isotopes, and source s o f all types.

$261 PREQUENCTI Whenever any radioactive materials are shipped or removed from RRF or transferred to the Reed College licence.

52 3 SPECIAL EQUIPMENT!

Tog R ADIDACTIVE M ATERI ALS TRANSFER forms separated by a sheet of carbon paper.

A cost.leted 14 form (for irradiated samples).

A, portable GM monitora The los ba=kground GM counter.

One Kiesipe

, Methahol 52a4 PERSONNEL! ,

One RRF staff member 6 .

The person (s) removing / shipping the radioactive materialsa (These may and have, at times, been one and the s ame) 52s5 PRELIMINART ACTIONS:

Set up the los background counter in the reac tor room and start a five minute background count.

5246 PROCEDURE:

~~ Fill out the first too sections of the Ra0IDACTIVE MATEPIALS TRANSPER form obtaining the transfer number by adding one to the latest transfer number posted on the blackboard. Check the Appropriate box for materials shipped or removed (ma-terials removed are those taken away by the experimenters themselves rather than being shipped via a public carrier.

Indicate the means of transport used in the box provided le.

pr1 Vale autos UPS, 4tc. The rectoients license number must be found on a copy of their current licence in the console

. , , , Poom file cabinet. No material shall be released eithout a copy of the recipien t's licence on file. Indicate the go,-

eral type of materi'al being trans f erred, whether geological

,,_ samples, physiological salinee etc. and the estimated activ-ity in mil 11 curies.

Before packaging, monitor the material itself at one foot from its surface with the GM portable ionitor and record this reading on the transfer form. After packaging, monitse the package at its surface and at one meter from its sur-f aces Nextl eoisten a-Kissipe eith methanol and wipe a representative area,usually a bottom edge and corner and the top and closure of the container and place the kimelpe in the los background counter for a one sinute count and deter-mine the not beta-gassa counts above back- ground, record 411 of this monitoring information on the trandsfer form and applicable parts in the appropriate olank s of the IR fori.

In the blank for remarks record the type o f packaging, la-Section G continued on next page -

46 G.7 R ADIDACTIVE M ATERI ALS TR AN3FER: sooS2 i

belling, and any other useful information about the package and shipping procedure.

l See the appendix to this son and the Summary of Federal Regulations for eackaging and Tran-

' sportation of Radioactive Materials to be found on file in the console room under " shipping information" for further

,informatione 52a7 ADJUSTMENTS!

Insure that all labelling on the packages to be shipped or removed is correct tion of the applicable and that the materials are not in viola-state and/or federsi regulations by

"" adding more shielding or packaging, or by breaking a large shipment up into smaller ones.

52a8 CLEANUP!

Check to see. that all blanks have been filled in and that all signatures have been obtained on the transfer form and IR forma Mate sure the package has a seal such as tape or strea Give the carbon of the transfer fore and the orange sheet of the I,R to the experimenter / shipper with the materi-als involved and file the_ originals in the console room fil-ing cabinet. Turn off the los background counter and the portable sonitorsa 5249 LDGGING int Log the shipment in the console log book and update the

" latest transfer" number on the blackboard.

$2410 APPENDIX!

' ~ ~ ~ Useful information from the Summary of *ederal Regulations foF Packaging and TFansportation of Radioactive Materials:

Is Removable contamination is considered insignificant if the not beta gamma count is ( 2,200 dos /100sq.ca.

iia Labelling!

~~"

As shite radioactive I label:

~

C 0.5 mR/hr at surface as yellos radioactive II label: < 10 mR/hr at surface,

< 0.5 mR/hr at 1 meter or Transport Index < 0.5 C4 yellos radioactive III label: > 10 se/Mr fissile c' lass III see Federal Rogs.

, IIIa Peckiging!

Package iust have a seal over opening to ensure contents arrive undisturbed ie. tape or lead sire.

No dimension of the package may be less than 4" for shipping by public carrier.

No , pack age may read > 200 mR/hr at its surface or

> 10 mR/hr at 1 meter for postal shipping.

last revised 08/17/81

- End of Section G -

END OF EXAMINATION

. * 't EQUATION SHEET Where o g=m2 (density)g(velocity)g(area)g = (density)2(velocity)2 I 'I Z KE = mv 2 PE = agh PE1 +KE1 +P1 V 2

1 = PE 2+KE2+P22 V where V = specific volume P = Pressure 0 = mcp (Tout-Tg ,) 0 = UA (T,,,-T,g,)

Q = a(hg-h2 I P = P,10(SUR)(t) p ,p ,t/T g SUR = 26.06 T = 1/ Delta k T

delta K = (K,ff-1)/K,ff CRg(1-K,ffg) = CR2 II*Keff2) CR = S/(i.K,ff)

M= (1-K,ffg) SDM =

(1-K,fg) x 1001 (1-K eff2 I K eff decay constant = In (2) = 0.693 Ag = A,e-(decay constant)x(t)

I t I/2 1/2 Water Parameters Miscellaneous Conversions 1 gallon = 8.345 lbs 10 dps 1 Curie = 3.7 x 10 1 gallon = 3.78 liters I kg = 2.21 lbs 1 ft3 = 7.48 gallons I hp = 2.54 x 10 3 8tu/hr Denst.ty = 62.4 lbm/ft 3 3

1 MW = 3.41 x 106 Btu /hr Density = 1 ge/cm 1 Stu = 778 ft-lbf Heat of Yaporization = 970 Btu /lbe Degrees F= (1.8 x Degrees C) + 32 Heat of Fusion = 144 Btu /lba 1 inch = 2.54 centimeters 1 Atm = 14.7 psia = 29.9 in Hg g = 32.174 f t-1bm/1b f-sec2 e