ML031700562
| ML031700562 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 05/19/2003 |
| From: | Gumbert R AmerGen Energy Co |
| To: | Conte R NRC/RGN-I/DRS/OSB |
| Conte R | |
| References | |
| 50-289/03-301 50-289/03-301 | |
| Download: ML031700562 (9) | |
Text
May 19,2003 NRC SRO Initial License Written Exam Ex Comment Answer Key identifies D as the correct answer, stating that Pressurizer system failure has occurred. Answer B can also be a credible answer if loss of SIlMU occurs.
In order to select answer D, the examinee must assume the Pressurizer system failure. Given that the Loss of MUlSl procedure is included in 3 of the 4 answer choices, assuming loss of MUlSI has occurred is not unreasonable.
As written, there is no correct answer provided.
Based on the OS-24 definition for Available as a Heat Sink, Rule 4, FW Control, does not apply.
Answer Key is not correct.
mlAnswer Key Adjustments Resolution Acxot both B and D as correct answers.
With loss of RCP seal injection, seal
- 2 leak-off would provide a transport flow path to carry high activity RCS water to the RC Drain Tank, even in the absence of a Pressurizer system failure.
Even though this bank question was previously approved and used in the 2001 TMI NRC SRO written exam as written, it will be edited in the TMI question bank to preclude 2 correct answers for future use.
Delete this question IAW ES-403 Section D.l.b, since there is no correct answer provided.
The intent of question was to have two Pressurizer level channels inoperable in excess of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, to require a Tech Spec shutdown. As written, LI-777 is still operable. Therefore there is no correct answer given. This question will be edited prior to entry into the TMI question bank to represent conditions with both level channels inoperable.
Chanae correct answer from A to D.
Since OS-24 states that a dry OTSG is not considered available as a heat sink, Rule 4, FW Control, does not apply to the conditions in the question stem. Therefore, Guide 13, Dry OTSG, applies. Edit this question prior to entry into TMI question bank: stem should state that both OTSGs are NOT dry.
Chanae Answer Kev from B to C.
This question was apparently edited, and then answers B and C were interchanged for psychometric considerations. This change brings the Answer Key into conformance with the NRC approved question and discriminant validity statements.
Reference shows flow path from Seal #2 leak off to the RC Drain Tank.
RCS P&ID 302-650 TS 3.5.5, Accident Monitoring Instrumentation, and bases, pages 3-40a, 3-40b, and 340c.
Page 340b states LT-1 and LT-3 are common to ONE channel, and that LT-777 is the other channel.
OS-24, Conduct of Operations During Abnormal and Emergency Events, Rev 7, Section 3.9.
Abnormal Transients Rules, Guides and Graphs, Rev. 1 - Rule 4, FW Control, and Guide 13, Dry OTSG.
Form ES-401-6 for Question #74, as approved by the NRC during week of April 7, 2003, Examiner prep week.
OP-TM-EOP-01 0,
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p h k b n 4 n t situations w h i c h could represent or lead to inadequate core cooling or evaluate and p d i c t Ms.course of accidents-beywrd me des&?
1 Specificatfa 3.5.5.1
-The minimum nurrber of Ehannels identifled for the instruments in
- ' Table 3.5-2, shall be OPERABLE.
W i t h the nunber o f instrunentaUon channels less than the ctr;annel(s) to W pressurizer lev (6) burs and in Cot0 StlUToOkM within an additional 30 huurs. Prior t o starttp f o l l o w i r g a COLD S",
the uiinimm nmfxr of channels shown in Table 3.5-2 shall be operable.
3.5.4.2 T k channels identlfled for the instruments speciTi'led in Table 3-5-3 shall be OPDZABLE. WiW the number of instrumentation channels less thart required, sestore.the Inoperable &annel(s) to D P E W E in accurdance uith the attion specified in TaDle 3.3-3.
Bases The Saturation Mixfgin Monitcrr provides a quhk and means for determination o f saturation temperature margins, and calculation oT saturation pressure end saturation temperature margins can be easily and quickly performed as an alternate indicathm for me Saturation Hargin Monitars.
Discharge flm T m the two (2) pressusher code safety valves and the PORV Is measukd by differential pressure transmMzrs connected across elbow taps downstream of each valw.
A delta-pressure indicaffun from each pressure transmitter is availaole in the c a n t n l mom tu Indicatecode safetyor relief valve line flow.
An alarm is also provided in tW controll mom.to indicate that discharge f r o m a pressurizer code safety CIZ: relief valve is occurring.
In addition, an acoustic monitor is provided t o detect flow in the PURV discharge line. An alarm is provided in tne control mm for the amustic monitar.
3.5.5 ACCIDENT MONITORING INSTRUMENTATION (Continued)
The Emergency feedwater System (ENV) is provided with two channels of flow instrumentation on each of the two discharge lines. Local Row indication is also available for the ERN System.
Although the pressurizer has multiple level indications, the separate indications are selectable via a switch for display on a single display. Pressurizer level, however, can also be determined via the patch panel and the computer log. In addition, a second channel of pressurizer level indication is available independent of the "1.
Although the instruments identified in Table 3.5-2 are significant in diagnosing situations which could lead to inadequate core cooling, loss of any one of the instruments in Table 3.5-2 would not prevent continued, safe, reactor operation. Therefore, operation is justified for up to 7 days (48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> for pressurizer level). Alternate indications are available for Saturation Margin Monitors using hand calculations, the PORWSafety Valve position monitors using discharge line thermocouple and Reactor Coofant Drain Tank indications, and for ENV flow using Steam Generator level and ERN Pump discharge pressure. Pressurizer level has two channels, one channel from NNI (2 D/P instrument strings through a single indicator} and one channel independent of the NNI. Operation with the above pressurizer level channels out of service is permitted for up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.
Alternate indication would be available through the plant computer.
I The operability of design basis accident monitoring instrumentation as identified in Table 3.5-3, ensures that sufficient information is available on selected plant parameters to monitor and assess the variables fallowing an accident. (This capabitity is consistent with the recommendations of Regulatory Guide 1.97, "Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant Conditions During and Following an Accident," Rev. 3, May 1983.) These instruments will be maintained for that purpose.
3-40b Amendment No.
I
,242
3 2
(D 7
0 z a FUNCTION INSTRUMENTS I
Saturation Margin Monitor N,
P N
2 Safety Valve Differential Pressure Monitor 3
PORV Position Monitor 4
Emergency Feedwater Flow 5
Pressurizer Level 6
Backup lncore Thermocouple Display Channel x
0 c)
TABLE 3.5-2 ACCIDENT MONITORING INSTRUMENTS NUMBER OF CHANNELS MINIMUM NUMBER OF CHANNELS 2
1 1 per discharge line 1 per discharge line 2
1' 2 per OTSG 2
. I 1 per OTSG 4 thermocoupleslcore 2 thermocoupleskore quadrant quadrant
- With the PORV Block Valve closed in accordance with Specification 3.1.12.4.a, the minimum number of channels is zero.
TMI - Unit 1 Operations Department Administrative Procedure Title Conduct of Operations During Abnormal and Emergency Events 3.7 3.8 3.9 3.10 3.1 1 3.12 3.13 Number OS-24 Revision No.
7 LACK OF PRIMARY-TO-SECONDARY HEAT TRANSFER (LOHT) is the inability of either OTSG to remove sensible heat from the RCS. LOHT can be confirmed if :
e Neither OTSG has water level control and pressure control.
Core exit temperatures are rising AND e
MINIMIZE SCM: An intentional reduction of the reactor coolant pressure temperature relationship as close as practical to the 25°F subcooling margin or emergency RCP NPSH limit. (Recommended band 30-70°F)
OTSG AVAILABLE AS A HEAT SINK:
A physical condition where the OTSG demonstrates level and pressure control, used to determine if primary to secondary heat transfer is possible. (i.e. heat sink) Primary to secondary heat transfer need not be demonstrated to determine this availability. Primary to secondary leakage should not be considered a means of OTSG level control. A dry OTSG is not considered available as a heat sink.
OVERSIGHT:
The independent monitoring of plant and crew performance and any subsequent intervention, as needed, to ensure the appropriate mitigation strategy is being pursued for the current plant conditions. Refer to Attachment B, SM Oversight Management Guidelines.
PLAN NED REACTOR TRIP A scheduled shutdown, where a reactor trip, is directed by an approved procedure.
PRIMARY-TO-SECONDARY HEAT TRANSFER (PSHT) is the removal of sensible heat from the RCS to one or both OTSG(s). PSHT can be confirmed if:
e Either OTSG has water level control and pressure control.
RCS T, is approximately the same as secondary TSat and responds to changes in OTSG pressure.
RCS forced or verified natural circulation is present.
AND AND e
RCP AVAILABLE -An available RC Pump is one which can be operated without extraordinary efforts. Pump service functions (motor cooling, seal cooling, etc.) are operable (redundancy not required) and all interlocks can be satisfied. Strict compliance with administrative shutdown criteria (vibration, seal leakoff flow, etc) is not expected when the operation of the pump is more important to safe plant operation.
4
OP-TM-EOP-010 Revision 1 Page 8 of 49 ACTION/EXPECTED RESPONSE FWC RESPONSE NOT OBTAINED Rule 4 Feedwater Control ACTION/EXPECTED RESPONSE A.
IAAT the reactor is shutdown, then:
~
RESPONSE NOT OBTAINED VERIFY SCM > 25°F.
I...............................................
VERIFY at least 1 RCP operating.
MAINTAIN OTSG level 2 25 STARTUP Range Level.
MAINTAIN OTSG level 75 - 85%
OPERATING Range Level.
MAINTAIN OTSG level 2 50% OPERATING Range Level.
B. If Level c: minimum, then MAINTAIN the following MINIMUM required flow:
If SCM < 25OF and both OTSGs are available, then FEED > 215 gpm/OTSG using EFW.
If EFW is K t available, then FEED 1.O Mlbm/hr using MFW.
If SCM 25OF and onlv one OTSG is available, then FEED > 430 GPM to the good OTSG using EFW.
If EFW is not available, then FEED
> 1.0 Mlbm/hr using MFW.
If RCPs are OFF, then FEED OTSG at maximum available using EFW, within RCS Cooldown rate limit.
There is no minimum required flow rate.
If EFW isnot available, then FEED
> 1.O Mlbm/hr using MFW.
1..
I OP-TM-EOP-010 Revision 1 Page 26 of 49 Guide 13 Drv OTSG
- 2. MONITOR Tube to Shell Differential Temperature (TSDT) and REVIEW Guide 14.
- 3. VERIFY the other OTSG is available.
- 4. VERIFY all RCPs are OFF or TSDT Limits are being challenged GO TO Step 5.
NOTE Automatic EFW actuation is not restricted by this guidance. Limit feedwater flow to the Dry OTSG until OTSG pressure has been restored. RCP operation is desired.
- 5. VERIFY the DRY OTSG pressure boundary is INTACT.
- 6. If TSDT tensile limit is being challenged,
- then,
- 7. If TSDT compressive limit is being challenged, then,
VERIFY the OTSG pressure boundary failure is not in the Intermediate or Reactor Building.
If RCPs are OFF, then FEED the DRY OTSG at a maximum of I 8 5 GPM using EFW.
If RCPs are OFF, then FEED the DRY OTSG at a maximum of 185 GPM using EFW.
Page # 3.9-2 1
Knowledge of the physical connections and/or cause-effect relationships between Liquid Radwaste System (LRS) and the following systems: Sources of liquid wastes for L 2.9 Group #
ROlSRO Importance Rating 2.7
@I
-2 Plant conditions:
- Reactor power is loo%, with ICs in full automatic.
Based on these conditions, identify the ONE selection below that describes a NORMAL source of water to the Liquid Waste Disposal System.
A. PORV pilot valve leakoff.
B. Leakoff from between the reactor vessel flange O-Rings.
C. Intermittent drain flow from the Waste Gas Compressor Separator.
D. Valve packing leakage from Letdown isolation valves MU-V-1A and MU-V-1 B.
302-696, Waste Gas Compressors Flow Diagram, Rev. 1.
None.
.09.01 New 0 c1 0
Modified TMI Bank Parent Question #
Memory or Fundamental Knowledge Comprehension or Analysis
@I 55.41.2 to.9 55.43 55.45.7/.8 A Incorrect answer.
B Incorrect answer. This line is normally isolated.
C Correct answer. Level switch operates solenoid operated valve to drain excess water from the separator to the Auxiliary Building Sump.
D Incorrect answer. Packing leakoff lines are capped.
None.