ML20245C684
| ML20245C684 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 09/30/1987 |
| From: | Kuncl L NEBRASKA PUBLIC POWER DISTRICT |
| To: | Whittemore J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| Shared Package | |
| ML20245C465 | List: |
| References | |
| NUDOCS 8711030402 | |
| Download: ML20245C684 (22) | |
Text
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GENER AL OFFICE e
T:
Nebraska Public Power District
- "?etss"cSSEss^M"*"[
4 f
4 OCT l 19P September 30, 1987
'i
,i a i U.S. Nuclear Regulatory Commission Ryan Plaza Drive Suite 1000 Arlington, TX 76011 Atta:
John N. Whittemore S ubj e c t :
Comments - NRC Examination Administered September 22-24, 1987
Dear Mr. Whit t emo re :
Attached piense find our comments on the questions and answers associated with the subject examinations given on September 22, 1987. We believe that our concerns and comments should be considered in the grading of the written exams administ ered and, in some cases, serve as a basis for refining several of the examinat. ion questions and answers.
Please contact us if you would like to pursue our comments f urther or if ad-ditional clarification is desired.
Sinc oly,
/
/
1 a
W if L. G. K nel Vice-President - Nuclear
/dkh Attachment ec:
G. A. Trevors w/ attachment G.
R. llorn w/ attachment J. W. Dutton w/ attachment K. C. Walden w/ attachment R.
Brungardt w/o attachment C.
11. Reece w/o attachment F. K. Finn w/o attachment i
TS File w/ attachment l
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Attachment l
1987 SRO LICENSING EXAM COMMENTS Comments from the'SRO NRC Examination Review performed on September 22-24, 1987. The following CNS personnel were involved in the review of the exams:
G. H. Reece D. L. King D. A. Sha11enberger M. W. Parrish (GE) i l
J. E. Surette (GE)
E. P. Matzke (GE)
Comments are listed by Section Question Number.
1
NRC EXAM COMMENTS 4
QUESTION 5.03 (1.00)
List THREE generic factors that can affect Control Rod worth in a given reactor.
(1.0)
ANSWER 5.03 (1.00) 1.
Size of the rod 2.
Flux distribution (rod location) 3.
Moderator temperature 4.
Type of absorber material (Any 3, 0.33 ea.)
(1.0)
REF CNS Rx. Theory, Pg. 5-29, 5-30 292005K109
...(KA'S)
COMMENT The Reactor Theory text, page 5-11 says that anything that effects neutron flux will affect control rod worth.
RECOMMENDATION Answer should include anything that effects thermal neutron flux such as:
voids, core age, peaking factors, poisons, span / pitch.
CNS REF Rx Theory Chapter 5, Pg. 1-13 and 29-30
l l
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l QUESTION 5.09 (2.00)
Explain how and why the following factors affect the magnitude of the Doppler coefficient over core life.
a.
Pu-240 buildup.
(1.0) b.
Fuel swelling.
(1.0)
ANSWER 5.09 (2.00) a.
Increase (0.5) More resonance peaks absorb neutrons. (0,5)
(1.0) b.
Increase (0.5) Gap decreases, fuel temp decreases, less peak overlap.
So, Doppler increases. (0.5)
(1.0)
REF CNS HT&FF Theory, Pg. 4-41, 4-42 292004K109 292004K108
...(KA'S)
C0KMENT Question could also be answered based on the effects that swelling has on the pellet besides temperature changes.
RECOMMENDATION Accept answers that discuss change based on atomic concentration (N) and self-shiciding in the pellet.
REF
QUESTION 6.02 (2.50)
The Reactor Recirculation System interfaces with several other plant systems. Describe it's interaction with the following systems.
(Be specific as to the point of interface on the Rx. Recirculation system.)
a.
Reactor Water Cleanup (RWCU) System.
b.
Control Rod Drive (CRD) Hydraulic System.
c.
Average' Power Range Monitoring (APRM) System.
d.
Residual Heat Removal (RHR) System.
Reactor Equipment Cooling (REC) System.
c.
ANSWER 6.02 (2.50) a.
The RWCU takes suction from the "A" recirculation loop.
(0.5) b.
The CRD hydraulic system supplies the purge flow to the recirculation pump mechanical seals.
(0.5)
Recirc. Loop Flow elements provide input signals to the APRM flow c.
(0.5) converters.
d.
The recire. loops provide suction and return paths for RHR in the shutdown mode.
(0.5)
The REC system provides the necessary cooling water to the recire.
e.
pump motors and mechanical seals and cooling water from the MG set oil system.
(0,5)
REF OSTM BK. 2, Chap. 2, Pg. 41 20200lKKil 20200lK107 202001K110 20200lK121 202001K123
...(KA'S)
COMMENT The RHR system also utilizes the recirculation loops for the LPCI mode injection.
RECOMMENDATION Accept RHR LPCI mode discharge to recire. loops as an answer.
REF l
RHR Student Text Pg. 43
{
1
QUESTION 6.03 (3.00)
Concerning the electrical power distribution system:
a.
What are the two (2) major 480 VAC powered components that are not affected by 4160 VAC load shed?
(0.5) b.
What design feature determines if a supply breaker for a 480 VAC Motor Control Center will automatically trip during load shedding?
(0.5) f c.
Describe two (2) conditions that must be met to close a 4160 VAC bus power supply breaker from the control room.
(1.0) d.
Explain the reason for the caution p. late on Ooard "C" requiring that 4160 VAC breaker 1AF is to be closed before the operator attempts to close breaker IFA.
ANSWER 6.03 (3.00) a.
1.
CRD Hydraulic Pumps 2.
Station Air Compressors (0.25 ea.)
(0.5) b.
Breakers whose control circuitry do not have UNDERVOLTAGE COILS will remain closed upon loss of power.
(0.5) c.
1.
All protective relays must be reset.
(0.5) 2.
The Sync. Switch for the selected breaker must be taken to the "0N" position.
(0.5) d.
An interlock between the breakers prevents backfeeding the non-critical bus from the critical bus.
(0,5) The interlock is an undervoltage coil on the bus between the breakers that must be energized or breaker IFA will trip.
(0.5)
(1.0) j i
REF OSTM BK. I, Chap. 9, Pg, 14, 31, & Table 5 26200lK404 26200lK401 262001A102
...(KA'S)
COMMENT Answer is incorrect since both the air compressors and CRD pumps have undervoltage devices. All MCCs off this bus are 460V and therefore cannot be considered 480V loads.
RECOMMENDATION Delete part "a" since there are no applicable loads relating to this question.
REF Burns and Roe' Drawing'3002 AC Text Rev 2 Page 15-17
t (QUESTION 6.03 CONTINUED) f COMMENT There are a lot of conditions that must be met to close a 4160V breaker from the control room. Generically, the two given answers are correct, however; individual breakers have additional requirements that must be met.
For example: breaker IAF requires either voltages on lA or breaker IFA open and UV on lA.
Other generic conditions include:
125 VDC available, breaker racked in.
RECOMMENDATION l
Accept 125 VDC available, breaker racked in, deenergized bus, or any other reasonable answer for this question.
REF Burns and Roe Drawing 3017 l
i
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l i.
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J
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i I
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i QUESTION 6.04 (3.00) l
~
For the following RCIC system valves, supply the following information:
1.
Specific motive power for operating the valve.
{
2.
Normal position j
3.
Auto open signals / conditions 4.
Auto close signals / conditions a.
Inboard Steam Isolation Valve (M0-15) l b.
Outboard Steam Isolation Valve (M0-16) c.
Steam Supply Blocking Valve (MO-131) d.
Turbine Trip Throttle Valve (3.0)
Responses should be numbered a.1, a.2, a.3, etc. ANb numbered setpoints are NOT required for full credit.)
i ANSWER 6.04 (3.00) a.1 AC a.2 Open a.3 Rx. vessel low-low level a.4 Gp. V isolation b.1 DC b.2 Open b.3 Rx. vessel low-low level b.4 Cp. V isolation c.1 DC c.2 Closed c.3 Rx. vessel low-low level c.4 Rx. vessel level high d.1 AC/ Spring d.2 Open d.3 None (0.15 ea.)
(2.25) d.4 Loss of lube oil pressure, low pump suction pressure, high turbine exhaust pressure, overspeed, Gp. V isolation.
(0.15 ea.)
(0.75)
REFERENCE OSTM BK. IV, Chap. 7 Pg. 8-12 217000K201 217000K102 217000K402
...(KA'S)
1
' QUESTION 6.04 CONTINUED d.1 COMMENT The turbine trip throttle valve is not powered by AC it is spring closed and is opened by an AC powered reset device.
I RECOMMENDATION Accept spring as the motive force for the turbine trip throttle valve.
i REF RCIC Student Text Pg 11 d.3 COMMENT I
The trip throttle valve will also automatically open (resets) if M0-131 is shut, however cleaing MO-131 is normally a manual operation so students may or may not consider this an automatic action.
RECOMMENDATION Accept either none or closure MO-!31 as an answer for d.3.
REF
(
RCIC Student Text Pg 12 q
j
t QUESTION 5.09 (1.00)
TRUE or FALSE:
a.
Once the Low Power Alarm Point is exceeded while increasing power, a software failure will still generate a Rod Worth Minimizer rod block.
b.
The Rod Sequence Control System (RSCS) group notch logic will block an " Emergency In" signal from the RMCS.
(0.5 ea.)
(1.0)
{
ANSWER 6.09 (1.00) a.
TRUE b.
FALSE REFERENCE OSTM BK. IV. Chap. 3 Pg. 13 201004K406 201006A207
...(KA'S) 6.09.a.
C0HMENT Two sections of the student text state that " hardware" failures cause rod blocks. One other section says that a software failure will cause a block. This could cause confusion.
RECOMMENDATION Accept True or False as the answer.
REF RWM Student Text Pg. 6-9 4
QUESTION 6.13 (2.00)
State the signals and setpoints which will automatically initiate the a.
Ltandby Gas Treatment (SGT) system.
(0.75) b.
State the specific actions that will result from the initiation of each signal chove. Discuss only those actions that occur in the SGT system, and include major post initiation actions that occur.
(1.25)
ANSWER 6.13 (2.'00) a.
High DW pressure 2 psig Low Rx. Vessel 12.5" High Rad. in the exh. plenum 100 mr/hr.
(0.15 for ea, signal and 0.1 for en setpoint)
(0.75) b.
For Rx. level & DW pressure:
Fans start, Train inlet / outlet valves open, d/p control valves operate to maintain 0.25' H20, Electric heaters maintain humidity
< 70%, and fan vortex operates to maintain flow and limit maximum d/p across filter train.
(0.15 ea.)
(0.75)
For high radiation:
All of the above plus: The exhaust valve from primary containment vent line to the RB exhaust plenum shuts, (0.25) and the valve from primary containment to the SGT.
(0.25)
(0.5)
REF OSTM BK. III, Chap. 3 Pg. 20, 21 261000K401
...(KA'S)
C0KMENT The student text and Tech. Specs, both state < 100 mr/hr as the setpoint for Reactor Building Exhaust high radiation, however; the present setpoint for RB exhoust high radiation is 10 mr/hr as stated in the instrument setpoint book.
RECOMMENDATION Accept 10 mr/hr or 100 mr/hr as the answer to this question REF Setpoint sheet for RMP-RM-452 A & B
i QUESTION 6.12 (2.00)
Concerning the Reactor Vessel Level Control system, answer the following TRUE or FALSE.
a.
Reactor Feed Pump (RFP) speed can be controlled by the Vessel Master Controller, the Dahl Controller, or the Startup Controller, m.
If Control Level "B" is lost while selected for control, switching to Control Level "A" will NOT clear the RFP lockout.
If Feed Flow "A" instrument is lost while at 50% power, the Dahl c.
controller will automatically assume control of RFP speed.
d.
In the " Balance" position, the Vessel Level Master Controller 9
deviation meter indicates the difference between the desired level and the actual level.
(0.5 ea)
ANSWER 6.12 (2.00) a.
False b.
True c.
False d.
False REF OSTM BK. III, Chap. 6, Pg. 9, 10, 18 216000Kil3 25900lK607 291003K108
...(KA'S) 6.12.b.
COMMENT Students answer will depend on what his interpretation of " clear" is.
A student may feel that clear means the lockup is reset or that the initiating signal is gone.
RECOMMENDATION Reword question for further exams to Le more clear.
l QUESTION 7.06 (2.50) j I
a.
What are three (3) different controls available to the control room j
operator to retard or prevent the automatic operation of ADS Safety / Relief valves.
(1.0) b.
What condition (s) should be verified before using any of these features or controls?
c.
What can the control room operator do to DEACTIVATE automatic operation of the ADS system?
(0.5) i d.
What conditions will cause automatic lowering of the setpoint of the two (2) lowest set relief valves?
(0.5)
ANSWER 7.06 (2.5) a.
ADS inhibit, ADS Timer reset, LLS Logic reset.
(0.33 ea.)(1.0) b.
Ensure level is increasing due to injection.
(0.5)
Place " ADS INHIBIT SWITCHES" to " INHIBIT."
(0.5) c.
d.
Any Safety / Relief valve has opened (0.2) AND (0,1) a HP Reactor Scram signal is present.
(0.2)
(0.5)
REF Proc. 2.2.1, Pg. 8-11 218000G002 218000G010 218000K402
...(KA'S) 7.06.a.
COMMENT Automatic operation of ADS may also be defeated by shutting off all Low pressure CSCS pumps which removes the permissive requiring 100 < 165 psig discharge from a low pressure coolant pump.
RECOMMENDATION Accept securing LP CSCS pumps as a means of preventing ADS initiation.
l QUESTION 7.03 (2.5)
For each of the following plant conditions or events:
1.
State the E0P(s) that should be entered by title or procedure number.
(Also state if no specific E0P entry is required.)
AND 4
2.
Cive the specific E0P entry condition met, including any applicable setpoints.
Supression Pool Temperature = 150*F a.
b.
Drywell Pressure = 2.25 psig Main Steam Line Rad Monitors read 3.5 times normal full power c.
background.
d.
Reactor Pressure = 1055 psig South CRD Equipment area radiation level = 55 mrem /hr.
(2.5) e.
ANSWL.,
7.03 (2.50)
Primary Containment Centrol - Sup Pool Temp > 95*F a.
b.
RPV Control and PC Control - DW pressure > 2.0 psig c.
None d.
PRV Control - > 1045 psig Secondary Containment Control - Area > 50 mrem /hr (0.5 ea.) (2.5) e.
REF CNS Proc.. 5.8, Pg. 1-4 & E0P 3 TAB. 3.2 272000K101 295024K0ll 295025K011 295026K011
...(KA'S) 7.03 COMMENT Question allows using procedure numbers in answer, but answer key does not show them.
RECOMMENDATION Allow procedure numbers as answers.
I 7.03.c COMMENT MSL high rad, of 3.5 times normal full power background is above the scram setpoint.
Students may assume that since a scram signal is present and power is still > 2.5% or unknown, an E0P entry condition for E0P-1 has been met.
RECOMMENDATION:
Accept E0P-1 as an answer to this question 4
__-__-__.m_.
QUESTION 7.03 CONTINUED REF Pag? I of E0P/c 7.03.e COMMENT Students are not required to memorize the E0P tables.
If an alarm condition arises, they are expected to reference the tables and respond i
accordingly.' The caution section of E0P's states entry conditions for the Secondary Containment Control (E0P-3) high radiation as > max normal.
RECOMMENDATION Accept E0P-3 or none as an answer.
REF Page 1 of E0P/c e
r l
1 8
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1
QUESTION 7.07 (2.5)
The reactor is at 100% power and it is suspected that an SRV is stuck open. Concerning Abnormal Procedure 2.4.2.3.1, " Relief Valve Stuck Open:"
If no position lights are lit, what are four (4) control roem a.
instrument indications that could be used to verify a stuck open valve?
(1.0) b.
After verifying that a valve is open, what are three (3) methods the operator can use to attempt closing the valve?
(1.5)
ANSWER 7.07 (2.5)
Change in DEH control, Change in Feedwater, Supression Pool Level, a.
Supression Pool Temperature, Computer, SPDS valve position, Tail Pipe Temperature.
(any 4, 0.25 ea) b.
1.
Cycle Switch Between Auto and Manual 2.
Turn ADS inhibit Svi.tches to " INHIBIT" position 3.
Remove fuses in th Auxiliary Relay Room panel.
(0.5 ea.)
(1.5)
REF Proc. 2.4.2.3.1, Pg. 2, 3 2239002A401
...(KA'S) 7.07.a.
COMMENT A similar question based on this same procedure was asked on an exam given 3/4/86. At that time a recommendation was made and accepted to allow any reasonable answer.
RECOMMENDATION I
Accept any reasonable answer such as Stm./ Feed flow mismatch, gen, load reduction, 30 psig tail piece amber light, etc.
Please modify answer key for future use.
REF Comment, question, and answer from exam given on 3/4/06, Question #7.11.
7.07.b.
COMMENT l
Along with the actions stated in the answer key, the procedure also tells the operators to check N pressure and correct if too high and reduce 2
power to reduce pressure.
I QUESTION 7.07 CONTINUED RECOMMENDATION Accept reference to N Pressure and power reduction as correct answers.
2 REF Abnormal Procedure 2.4.2.3.1 Pg. 3 a
i i
QUESTION 7.09 (3.00)
Concerning the trip of a Reactor Recirculation (RR) Pump at power, answer the following TRUE or FALSE and explain why; a.
If the operator determines that the plant is operating in the
" Instability Region,".the only option allowed by the procedure for attaining stability is to push rods.
(1.0) b.
The operator is allowed to correct flux oscillations only by changes in Contr'ol Rod position (1.0) c.
The requirement that IDLE loop temperature must be within 50* of core inlet temperature to restart the RR pump is based on thermal shock to RPV RR inlet piping and Rams Heads.
(1.0)
ANSWER 7.09 (3.00) a.
False (0.5)
Procedure also allows for increasing flow using the unaffected pump. (0.5)
(1.0) b.
True (0.5) As this would counter effect the attempt to attain stability.
(0.5)
(1.0) c.
False (0.5) Based on possible RR pump damage.
(0.5)
(1.0)
REF Proc. 2.2.68, Pg. 13, 14, & Proc. 2.4.2.1.1, Pg. 2, 3 202001A203 202001A221
...(KA'S) 7.09.b.
COMMENT Procedure 2.1.10 Rev 13 Page 2 indicates that oscillations may be supressed by inserting control rods and/or increasing core flow.
The preferred method is to reverse the actions that caused the flux oscillations.
RECOMMENDATIONS The answer should be FALSE for reasons discussed above.
REF General Operating Procedure 2.1.10 Pg. 2 i
QUESTION 7.10 (2.00)
I Define or explain, " Limiting Control Rod Pattern."
(0.5) a.
b.
Who is normally responsible for determining and reporting that a
" Limiting Control rod Pattern" exists?
(0.5) c.
What are 2 of the 3 "Special Operations" that may cause a limiting pattern?
(0.5) d.
List 2 of the 3 conditions, actions, or limits any one of which the f
operator may choose to initiate or impose, if forced to operate with 1
a limiting pattern.
ANSWER 7.10 (2.00)
A pattern which contains a rod which, if completely withdrawn, could a.
result in a MCPR < l.07.
(0.5) j b.
Reactor Engineer
{
c.
1.
Interchange of normal patterns (due to burnup).
{
2.
Establishing special patterns in order to locate failed fuel.
3.
Establishing special patterns due to CRD system malfunction.
(any 2, 0.25 ea.)
(0.5) d.
1.
Both RBM channels in service.
2.
Tag out Rod movement control switch.
3.
Limit reactor power so that error will not result in MCPR going below 1.07.
(any 2, 0.25 ea.)
(0.5)
REF Proc. 2.4.1.4, Pg. 1, 2 201002G001 201002K015
...(3'S) 7.10.a.
COMMENT Since the question did not reference a specific procedure, the students may have defined a limiting control rod pattern as a pattern which results in the core being on or beyond a thermal hydraulic limit. This is the new definition as shown in the Tech Specs and procedure 10.10.
Procedure 2.4.1.4 still shows the old definition as stated in the answer key.
RECOMMENDATION Accept "a pattern which results in the core being on or beyond a thermal hydraulic linit as an acceptable answer.
REF Nuclear Performance Evaluation Procedure 10.10 Pg. 2, TS 3/4.3 bases
QUESTION 7.11 (2.00)
Procedures warn the operator against tripping breakers IFE & 1GE j
a.
(EDG feeders to critical busses) if either the STARTUP or EMERGENCY Transformers are lost.
Explain the reason for this particular caution.
(1.0) b.
In the event that power is lost to the No-Break Power Panel because l
power does not transfer to MCC-R, what are two (2) actions that can
)
be taken by the operator to restore power.
(1.0)
ANSWER 7.11 (2.00)
These breakers have an anti-pump circuit which does not permit a.
reclosing if the closing signal is still present.
(1.0) b.
1.
Place the Bypass Transformer / Inverter Selector switch on Bd-C in the Bypass Transformer position.
I 2.
Operate the Static Switch IB Transfer Tast switch to the " FORCE TO AC LINE" position.
f i
3.
Place the CLOSE TO STARTUP SYSTEM switch on the inverter accessory module cabinet in the closed position.
4.
Operate switch S3 inside static switch cabinet to the "LINE" position.
(any 2, 0.5 ea.)
(1.0)
REF Proc. 2.4.6.2, 2.4.6.3, & 2,4,6,7 262001K406 262002K401
...(KA'S) 7.ll.a.
COMMENT Student may address a loss of DG auxiliary equipment such as HVAC which could result in an inop DG.
I RECOMMENDATION Accept loss of DG auxiliary equipment (HVAC) as an answer.
REF Tech. Spec. definition of operable.
QUESTION 8.10 (3.00)
~
A task must be performed in a 150 mrem /hr "High Radiation Area."
Consider the following individuals for the task by determining their allowable exposure, approvals that must be obtained, and stating any other considerations that must be made in accordance with CNS administrative procedures or any other applicable limits or guidelines.
Indicate how long each eligible individual would have to complete the
- task, A 22 year old male contractor has received 400 mrem in the current a.
quarter with a lifetime exposure of 19.5 Rem.
He has a current NRC FORM-4 on file.
b.
A 27 year old male CNS employee with a 35 Rem lifetime exposure has accumulated 50 mrem during the present week which is also his quarterly exposure.
c.
A 24 year old female, 2 months pregnant, has received prenatal exposure training and has opted to accept the provisions of Regulatory Guide 8.13.
Her current second quarter exposure is 20 mrem, which is also her exposure for the year.
Approval Titles not required, just exposures where approvals are required to complete task.
ANSWER 8.10 (3.00)
Contractor personnel are administratively limited to 1000 mr/qtr.
a.
and there are no daily or weekly limits. (0.5) That assumption alone would allow the worker 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to complete the job. A consideration to be addressed is exceeding the value for 5(N-18).
This would be lawful as long as he did not exceed the federal quarterly limit of 1.25 Rem /qtr. (0.5)
(1.0) b.
Station personnel are administrative 1y limited to 1000 mrem /qtr.
(0.25)
However they must have approval to exceed 150 mrem / day and 300 mrem /wk. (0.25) Thus with approval this individual could remain in the area for 950/150, or 6 1/3 hours. (0.5)
(1.0)
An individual who accepts the provisions of the Reg Guide is limited c.
to an exposure of 500 mrem for the entire gestation. (0.5) Thus, this person could work in the area for 480/150, or 3.2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. There would be N0 further exposure during the pregnancy. (0.5)
(1.0)
(If she is a CNS employee, she will need approval to exceed 150 mrem / day and 300 mrem /wk.)
REF Proc. 9.1.2.1, Pg. 5-7 29400lK103
...(KA'S)
QUESTION 8.10 CONTINUED 8.10.a.
COMMENT Station policy is never to exceed the 5 (N-18) limit. Although legally possible, exceeding 5 (N-18) is frowned upon by the NRC as indicated in a recent phone communication with Mr. Blaine Murray.
RECOMMENDATION Accept an ans'wer that reflects 100/150 hrs time (2/3 hr)
-l 8.10.b.
COMMENT The CNS employee could also have been authorized to exceed 1000 mr/qtr up to the federal limit of 3000 mr/qtr.
RECOMMENDATION Accept an answer of (3000
'50) = 2950 = 19 2/3 hrs 150 150 I
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-._-_.-_m.