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ILO24 > Tech Specs 3 > Flashcards

Tech Specs 3 Flashcards

RCS

1
Q

3.4 Reactor Coolant System

List the sections of the Reactor Coolant System tech specs group.

A

3.4.1 - Recirc Loops Operating
3.4.2 - Flow Control Valves
3.4.3 - Jet Pumps
3.4.4 - SRVs
3.4.5 - RCS Operational Leakage
3.4.6 - RCS Pressure Isolation Valve Leakage
3.4.7 - RCS Leakage Detection Instrumentation
3.4.8 - RCS Specific Activity
3.4.9 - RHR SDC System - Hot Shutdown
3.4.10 - RHR SDC System - Cold Shutdown
3.4.11 - RCS Press/Temp Limits
3.4.12 - Reactor Steam Dome Pressure

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2
Q

3.4.1 Recirculation Loops Operating

List the LCO and Applicability

A

LCO
A. Two recirc loops shall be in operation with matched flows;
or
B. One recirc loop shall be in operation with:
1. Thermal Power <= 2500 MWt;
2. APLHGR, LHGR, and MCPR limits modified for single loop operation IAW COLR limits
3. APRM Flow bias simulated thermal high power value adjusted for single loop operation.

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3
Q

3.4.1 Recric Loops Operating

List the jet pump flow differential limits

A

< 70% flow (<72.4 mlbm/hr) -> 10% (10.4 mlbm/hr)
> 70% flow -> 5% (5.2 mlbm/hr)

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4
Q

3.4.1 Recirc Loops Operating

What actions of this LCO have a requirement of completion 1 hour or less?
What is the action?

A

Action B: Thermal Power > 2500MWt during single recirc loop operation
Reduce thermal power to <= 2500MWt within 1 hour.

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5
Q

3.4.1 Recirc Loop Operating

When 2 recirc loops are operating, why are their flows required to be matched within limits?

A

The assumptions of a recirc loop break LOCA require these limits in order to satisfy the analysis.

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6
Q

3.4.1 Recirc Loops Operating Bases

What requirements exist when both recirc loops are in operation with flows mismatched?

A

Recirc loop flows must be matched within 2 hours.

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7
Q

3.4.1 Recirc Loop Operating Bases

When is a recirc loop considered to not be in operation?

A

Pump in the loop is idle or flow mismatch between total jet pmp flows is great than required limits. The loop with lower flow is considered not in operation.

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8
Q

3.4.2 FCVs

List the LCO and Applicability

A

LCO
Recirc loop FCV shall be operable in each operating recirc loop.

Applicability
Modes 1 & 2

Note Separate entry condition allowed for each FCV.

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9
Q

3.4.2 FCVs

What is the maximum speed a FCV can move in order to be considered operable?

A

FCV average rate of <= 11% of stroke per second in either direction.

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10
Q

3.4.2 FCVs Bases

Why are FCVs required to be OPERABLE in each operating loop?

A

Satisfy the assumptions of the design basis transient and accident analysis.

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11
Q

3.4.2 FCVs Bases

Why are the FCVs locked up when they are determined to be inoperable?

A

FCVs are locked up to prevent them from adversely effecting the reactor in a DBA or transient.

If the FCVs close too quickly, higher PCT would be achieved in a DBA LOCA.

If the FCVs open to quickly, the flow runout transient could be too severe and challenge MCPR.

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12
Q

3.4.3 Jet Pumps

List the LCO and Applicability

A

LCO
All jet pumps shall be operable

Applicability
Modes 1 & 2

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13
Q

3.4.3 Jet Pumps

What requirements must be verified to determine if jet pumps are operating correctly?

A

2 of 3 below criteria must be validated:

1. Recirc loop drive flow vs. FCV position differes by <= 10% of established patterns.

2. Recirc loop drive flow vs. total core flow differs by <= 10% from established patterns.

3. Each jet pump diffuser to lower plenum DP differs by <= 20% from established patterns, or each jet pump flow differs by <= 10% from established patterns.

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14
Q

3.4.3 Jet Pumps Bases

What is the reasoning behind the requirement of all Jet Pumps being operable?

What is required if a jet pump is inoperable?

A

Jet pumps compose an integral part of the boundary for the 2/3 refloodable volume.

If a jet pump is not operable, there is a potential that this volume is challenged. The reactor must be brought to Mode 3.

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15
Q

3.4.4 SRVs

List the LCO and Applicability

A

LCO
The safety function of 7 SRVs shall be operable
AND
The relief function of 6 additional SRVs shall be operable.

Applicability
Modes 1, 2, & 3.

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16
Q

3.4.4 SRVs Bases

What is the most secure pressure transient?
How does this transient relate to this LCO?

A

Most severe pressure transient is the closure of all MSIVs followed by a reactor scram on high neutron flux.

The analysis for this transient show that this configuration will maintain pressure to < 110% of design pressure.

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17
Q

3.4.4 SRV Bases

If the relief function of an SRV is not operable, is the valve considered inoperable for this LCO?

A

Not necessarily. If the valve is capable of opening on the Safety function, the valve can be considered operable for the Safety function requirement.

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18
Q

3.4.5 RCS Operational Leakage

List the LCO and Applicability

A

LCO
RCS Operational leakage shall be limited to the following:
1. No pressure boundary leakage,
2. <= 5gpm unidentified leakage,
3. <= 30 GPM total leakage averaged over the previous 24 hour period, and
4. <= 2gpm increase in unidentified leakage within the previous 24 hour period in MODE 1

Applicability
Modes 1, 2, and 3

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19
Q

3.4.5 RCS Operational Leakage Bases

Why does this LCO exist?

A

Operational leakage limits exist because action must be taken before the integrity of the RCPB is impaired.

20
Q

3.4.5 RCS Operational Leakage Bases

What constitutes unidentified leakage?

Why is the limit of 5 gpm established?

A

Drywell atmosphere monitoring, drywell floor drain sump level monitoring, and upper drywell air cooler condensate flow rate monitoring all comprise unidentified leakage.

This rate is established as a reasonable minimum detectable amount within a reasonable time period.

21
Q

3.4.5 RCS Operational Leakage Bases

Why is the 2 gpm increase in unidentified leakage increase only applicable in Mode 1?

A

The increase is relative to the steady state value. A temporary change due to transient is not considered.

22
Q

RCS PIVs

List the LCO and Applicability

A

LCO
The leakage from each RCS PIV shall be within limit.

Applicability
Modes 1 and 2.
Mode 3, except valves in the RHR SDC flowpath when in, or during the transition time from, the SDC mode of operation.

23
Q

3.4.6 RCS PIVs

What is considered acceptable leakby for an RCS PIV?

How does this leakage change with Reactor Pressure?

A

Acceptable leakby is <= 0.5 gpm per nominal inch of valve size up to 5 gpm at pressures between 1040 psig and 1060 psig.

As Reactor pressure changes, these values must be interpolated.

24
Q

3.4.6 RCS PIVs Bases

What are the RCS PIVs?

What are there purposes?

A

Any two normally closed valves in series with the RCPB.

Act as a barrier between the high pressure RCS and low pressure of attached systems (Like LPCS, RHR).

25
Q

3.4.6 RCS PIVs Bases

What systems have RCS PIVs?

Where would a list of these valves be found?

A

RHR
LPCS
HPCS
RCIC
SLC

ORM

26
Q

3.4.6

This LCO is not considered in the DBA. What purpose does it serve?

A

Provides for monitoring the condition of the RCPB to detect PIV degradation that has the potential to cause a LOCA outside of containment.

27
Q

3.4.6 RCS PIVs Bases

What are the consequences of not complying with this LCO?

A

The PIVs will further degrade and lead to the potential overpressurization of low pressure systems upstream of the RCPB. This will jeopardize the containment of fission products and present a high risk for a LOCA outside of RCPB.

28
Q

3.4.7 RCS Leakage Detection Instrumentation

List the LCO and Applicability.

What conditions exist requiring actions within 1 hour or less?

A

LCO
The following RCS leakage detection instrumentation shall be operable:
1. Drywell Floor drain sump monitoring system,
2. One channel of either drywell atmospheric monitoring system or drywell atmospheric gaseous monitoring systems, and
3. Upper drywell air cooler condensate flow rate monitoring systems.

Applicability
Modes 1, 2, & 3

1 Hour or Less Actions
With all required leakage detection systems inoperable, the plant must enter LCO 3.0.3 immediately.

29
Q

3.4.7 RCS Leakage Detection Instrumentation Bases

What is the purpose of the leakage detection systems for the RCS?

A

Alert the operators when leakage rates are above normal and supply quantitative measurements of those rates.

30
Q

3.4.7 RCS Leakage Detection Instrumentation Bases

Why are there systems for different types of leakage?

A

Quantify each type of leakage for the operator and permit them to take the correct immediate corrective actions.

31
Q

3.4.7 RCS Leakage Detection Instrumentation Bases

What type of leakage is the drywell floor drain sump?

What does the drywell floor drain sump monitor?

A

Unidentified Leakage

Collects leakage from the control rod drives, valve flanges or packings, floor drains, NCC, and drywell air cooling unit condensate drains.

32
Q

3.4.7 RCS Leakage Detecton Instrumentation

Why is the drywell atmosphere monitoring system considered as part of the RCS Leakage Detection Instrumentation?

A

RCS leakage contains gaseous radioisotopes that these monitors will detect.

33
Q

3.4.7 RCS Leakage Detection Instrumentation Bases

What part does the drywell air cooler condesnate flow play in leakage detection?

What does the instrumentation associated with this equipment sense?

A

A leak from the RCS system could potentially increase the overall humidity in the drywell.

Steam that leaks from this system would be condensed by the air coolers and measured in the condensate flow.

Its looking for an increase above the normal value by 1 gpm.

34
Q

3.4.8 RCS Specific Activity

List the LCO and Applicability

A

LCO
The DOSE EQUIVALENT I-131 specific activity of the reactor coolant shall be <= 0.2 microcurie/gm.

Applicability
Mode 1
Mode 2 and 3 with any MSL not isolated.

35
Q

3.4.8 RCS Specific Activity

What is the basis of this LCO’s limit?

A

This limit ensures that the 2 hour thyroid and whole body doses at the site boundary from a MSLB outside of steady state conditions will not exceed 10$ of the dose guidelines established by 10 CFR 50.67

36
Q

3.4.8 RCS Specific Activity Bases

Why is this LCO granted LCO 3.0.4.c provisions?

A

Transiting into an applicable mode is permitted because the limits established by this LCO are extremely conservative and there is a low probability of the limiting event occuring.

37
Q

3.4.9 RHR SDC - Hot Shutdown

List the LCO and Applicability

A

LCO
Two RHR SDC subsystems shall be operable and, with no recirc pumps running, at least one RHR SDC subsystem shall be operating.

Notes:
1. Both RHR SDC Subsystems and recirc pumps may be removed from operation for up to 2 hours per 8 hour period.
2. One RHR SDC subsystem may be inoperable for up to 2 hours for performance of surveillences.

Applicability
Mode 3 with steam dome pressure less than RHR cut in permissive (135#).

38
Q

3.4.9 RHR SDC - Hot Shutdown

What conditions exist requiring actions in 1 hour or less for this LCO?

A

With one RHR SDC subsystem inoperable, verify an alternate method of DHR is available within 1 hour and every 24 hours afterwards. If this action can not be completed, immediate commence action to restore RHR SDC subsystem to operable status.

With 2 RHR SDC Subsystems inoperable, verify an alternate method of DHR is available for each inoperable subsystem within 1 hour and every 24 hours afterwards. If this action can not be completed, immediately commence action to restore one RHR subsystem to operable status.

Note: the actions of LCO 3.0.3 and all other LCOs requiring a mode change to Mode 4 for this action may be suspended until a SDC subsystem is restored to operable status.

With no RHR SDC subsystem in operationg and no recirc pumps in operation, immediately commence action to restore one RHR SDC subsystem or one recirc pump to operation AND veritfy reactor coolant circulation by an alternate method within 1 hour of discovery, every 12 hours afterwards, AND monitor reactor coolant temperature and pressure every hour.

39
Q

3.4.10 RHR SDC - Cold Shutdown

List the LCO and Applicability

A

LCO
Two RHR SDC subsystems shall be operable and, with no recirc pumps running, at least one RHR SDC subsystem shall be operating.

Notes:
1. Both RHR SDC Subsystems and recirc pumps may be removed from operation for up to 2 hours per 8 hour period.
2. One RHR SDC subsystem may be inoperable for up to 2 hours for performance of surveillences.
3. Both RHR SDC subsystems and recirculation pumps may be removed from operation during inservice leak and hydrostatic testing.

Applicability
Mode 4 when heat losses to ambient are not sufficient to maintain average reactor coolant temperature <= 200F.

40
Q

3.4.10 RHR SDC - Cold Shutdown

What conditions exist requiring actions in 1 hour or less for this LCO?

A

With one or two RHR SDC systems inoperable, verify an alternate method of DHR is available for each inoperable RHR SDC subsystem within 1 hour and daily afterwards. If this action can not be completed, initiate action to restore RHR SDC subsystems to Operable status.

With no RHR SDC subsystem in operation and no recirc pumps operating, verify reactor coolant circulation by alternate means within 1 hour and every 12 hours after. Monitor reactor coolant temperature and pressure hourly.

41
Q

3.4.9 RHR SDC - Hot Shutdown Bases

What constitutes an OPERABLE RHR SDC subsystem?

A

RHR pump, two heat exchangers in series, associated piping, valves, instrumentation and controls are OPERABLE.

42
Q

3.4.9 & 3.4.10 RHR SDC

With one or no RHR SDC subsystem operable, action is required to verify alternate methods of decay heat removal available.

What constitutes an available alternate method of SDC?

List some examples of alternate DHR methods.

A

The alternate method must have sufficient cooling capacity to maintain or reduce temperature. Decay heat removal by means of ambient loss can be considered to contribute to the alternate method’s capability.

Examples of alternate DHR are the RWCU system, or an inoperable but functional RHR SDC system.

43
Q

3.4.11 RCS Pressure and Temperature Limits

List the LCO and Applicability

A

LCO
RCS Pressure, temperature, HUR, CDR, and Recirc Loop temperature requirements shall be maintained within limits.

Applicability
At all times.

44
Q

3.4.11 RCS Pressure and Temperature Limits Bases

What actions exist that require response in 1 hour or less for this LCO?

How does this LCO differ from other LCOs when an action is entered?

What is unique about applicability & violation of this LCO in different modes?

A

If the P/T limits, HUR/CDR limits, or RCS loop temperature limits are violated, action must be taken to restore parameters to within limits. Modes 1-3 allow for 30 minutes to complete, Modes 4, 5, and non-Moded operation (no fuel in the core) require immediate response.

This LCO is different as it does not follow the guidance of LCO 3.0.2, in that all actions of the Condition entry must be completed. This is required because a violation of these limits can result in brittle fracture vulnerabilities and the system(s) must be analyzed before further operation can take place.

The unique condition regarding applicability and violations of this LCO is that even with the vessel defueled, this LCO exists. The actions are more restrictive in lower temperature modes because lower temperatures mean less ductility and higher susceptibility to brittle fracture.

45
Q

3.4.12 Reactor Steam Dome Pressure

List the LCO and Applicability

Discuss any conditions that have actions requiring completion within one hour.

A

LCO
The reactor steam dome pressure shall be <= 1045 psig.

Applicability
Modes 1 & 2

1 Hour Actions
With reactor steam dome pressure not within limits, restore reactor steam dome pressure to within limits within 15 minutes.

46
Q

3.4.12 Reactor Steam Dome Pressure Bases

What is the bases of the pressure setpoint for this LCO?

A

Limit ensures the plant is operated within the assumptions of the vessel overpressure protection analysis. Operation above the limit may result in a transient response more severe than analyzed.

ILO24 (17 decks)

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