ML073230134

License Amendment Request, Proposed One-Time Changes to Technical Specifications Section 3.4.3.1 Reactor Coolant System Leakage Detection Systems

ML073230134
Person / Time
Site:	Limerick
Issue date:	11/16/2007
From:	Cowan P Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML073230134 (18)

Text

Exelon Nuclear www.exeloncorp.com 200 Exelon Way Kennett Square, PA 19348 Nuclear 10 CFR 50.90 November 16,2007 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Unit 2 Facility Operating License No. NPF-85 C Domt NO. 50-353

SUBJECT:

License Amendment Request Proposed One-Time Changes to Technical Specifications Section 3.4.3.1 Reactor Coolant System Leakage Detection Systems Pursuant to 10 CFR 50.90, "Application for amendment of license or construction permit," Exelon Generation Company, LLC (Exelon), proposes one-time changes to the Technical Specifications (TS), Appendix A of Operating License No. NPF-85 for Limerick Generating Station (LGS), Unit 2. The proposed one-time changes revise TS Limiting Condition for Operation (LCO) 3.4.3.1 Action requirements associated with inoperable reactor coolant system (RCS) leakage detection systems. In particular, a new TS Action requirement is proposed to be added that will allow the drywell unit cooler condensate flow rate monitoring system and one other RCS leakage detection system, other than the primary containment atmosphere gaseous radioactivity monitoring system (existing TS Action E), to be inoperable for up to 7 days. In addition, the 12- hour shutdown Action will be revised to require entry when any two or more leakage detection systems, other than Action E or the new Action, are inoperable or the individual Actions cannot be met in the allotted time. Also a footnote will be added to indicate that the proposed changes would only be effective for the remainder of the current operating cycle (Cycle lo), which is currently scheduled to end in the Spring of 2009, or until the next shutdown of sufficient duration to allow for drywell unit cooler condensate flow rate monitoring system repairs, whichever comes first.

License Amendment Request One-Time Changes to TS SR 3.4.3.1 (RCS Leakage Detection Systems) Docket No. 50-353 November 16,2007 Page 2 On April 14, 2007, it was noted that the drywell unit cooler condensate flow rate monitor increased from 1.6 to 3.2 gpm with no corresponding increase in identified or unidentified floor drain sump flow. Investigation into the increase in drywell unit cooler condensate flow determined that the "B" drywell unit cooler drain flow transmitter was saturated.

In this state, the drywell unit cooler condensate flow rate monitoring system would not be able to detect a change in leakage that is required by TS. Therefore, the drywell unit cooler condensate flow rate monitoring system was declared inoperable. The flow transmitter for the "B" drywell unit cooler is located inside the drywell and would require containment entry to conduct repairs. Therefore, the flow transmitter cannot be repaired until the next refuel outage currently scheduled for the Spring of 2009, or the next shutdown of sufficient duration to allow for drywell unit cooler condensate flow rate monitoring system repairs, whichever comes first.

Existing TS LCO 3.4.3.1, Action F requires that, with any two RCS leakage detection systems inoperable, other than those specified in Action E, the unit be in Hot Shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. With the drywell unit coolers condensate flow rate monitoring system already inoperable, existing TS LCO 3.4.3.1, Action F must be entered when certain TS surveillance testing is performed on the remaining operable RCS leakage detection systems. For example, a functional test and channel calibration of the drywell floor drain sump flow monitoring system are performed once every 31 days and 6 months, respectively. During the performance of these tests, the drywell floor drain sump flow monitoring system is declared inoperable.

As a result, the 12-hour shutdown Action required by existing TS LCO 3.4.3.1, Action F is entered because of both the drywell unit coolers condensate flow rate monitoring system and the drywell floor drain sump flow monitoring system being inoperable concurrently. The proposed changes include a new 7-day Action requirement that provides the ability to perform TS required surveillance testing and repairs, if necessary, on the other RCS leakage detection systems, as applicable, without being in a 12-hour shutdown Action statement because of the already inoperable drywell unit coolers condensate flow rate monitoring system. Attachment 1 provides the evaluation of the proposed one-time changes. Attachment 2 provides the marked-up TS page indicating the proposed changes. Attachment 3 provides the marked-up TS Bases page for information only. Exelon has concluded that the proposed changes present no significant hazards consideration under the standards set forth in 10CFR 50.92.

This amendment request contains no regulatory commitments. Exelon requests approval of the proposed amendment by November 16, 2008.

If current plant conditions change, Exelon may request NRC approval of the proposed amendment on an expedited basis. Upon NRC approval, the amendment shall be implemented within 30 days of issuance. The proposed changes have been reviewed by the Plant Operations Review Committee and approved by the Nuclear Safety Review Board.

License Amendment Request One-Time Changes to TS SR 3.4.3.1 (RCS Leakage Detection Systems)

Docket No. 50-353 November 16,2007 Page 3 We are notifying the State of Pennsylvania of this application for changes to the Technical Specifications by transmitting a copy of this letter and its attachments to the designated State Official.

If you have any questions or require additional information, please contact Glenn Stewart at 61 0-765-5529.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 16th day of November, 2007.

Respectfully, Pamela B. Cowan Director, Licensing

& Regulatory Affairs Exelon Generation Company, LLC Attachments:

1. Evaluation of Proposed Changes

2. Markup of Proposed Technical Specifications Page

3. Markup of Proposed Technical Specifications Bases Page cc: Regional Administrator - NRC Region I w/ attachments NRC Senior Resident Inspector - Limerick Generating Station NRC Project Manager, NRR - Limerick Generating Station Director, Bureau of Radiation Protection - Pennsylvania Department II II of Environmental Protection I1 ATTACHMENT 1 License Amendment Request Limerick Generating Station, Unit 2 Docket No. 50-353 EVALUATION OF PROPOSED CHANGES

Subject:

Proposed One-Time Changes to Technical Specifications Section 3.4.3.1 - Reactor Coolant System Leakage Detection Systems

2.0 PROPOSED CHANGE

S

7.0 REFERENCES

License Amendment Request Attachment 1 One-Time Changes to TS SR 3.4.3.1 (RCS Leakage Detection Systems) Page 1 of 8 Docket No. 50-353 Evaluation of Proposed Changes

1.0 DESCRIPTION

Pursuant to 10 CFR 50.90, "Application for amendment of license or construction permit,"

Exelon Generation Company, LLC (Exelon), proposes one-time changes to the Technical

Specifications (TS), Appendix A of Operating License No. NPF-85 for Limerick

Generating Station (LGS), Unit 2.

The proposed one-time changes revise TS Limiting Condition for Operation (LCO)

3.4.3.1 Action requirements associated with inoperable reactor coolant system (RCS)

leakage detection systems. In particular, a new TS Action requirement is proposed to be

added that will allow the drywell unit cooler condensate flow rate monitoring system and

one other RCS leakage detection system, other than the primary containment

atmosphere gaseous radioactivity monitoring system (existing TS Action E), to be

inoperable for up to 7 days. In addition, the 12-hour shutdown Action will be revised to

require entry when any two or more leakage detection systems, other than Action E or the new Action, are inoperable or the individual Actions cannot be met in the allotted

time. Also a footnote will be added to indicate that the proposed changes would only be

effective for the remainder of the current operating cycle (Cycle 10), which is currently

scheduled to end in the Spring of 2009, or until the next shutdown of sufficient duration to

allow for drywell unit cooler condensate flow rate monitoring system repairs, whichever

comes first.

On April 14, 2007, it was noted that the drywell unit cooler condensate flow rate monitor

increased from 1.6 to 3.2 gpm with no corresponding increase in identified or

unidentified floor drain sump flow. Investigation into the increase in drywell unit cooler

condensate flow determined that the "B" drywell unit cooler drain flow transmitter was

saturated. In this state, the drywell unit cooler condensate flow rate monitoring system

would not be able to detect a change in leakage that is required by TS. Therefore, the

drywell unit cooler condensate flow rate monitoring system was declared inoperable.

The flow transmitter for the "B" drywell unit cooler is located inside the drywell and would

require containment entry to conduct repairs. Therefore, the flow transmitter cannot be

repaired until the next refuel outage currently scheduled for the Spring of 2009, or the

next shutdown of sufficient duration, whichever comes first.

Existing TS LCO 3.4.3.1, Action F requires that, with any two RCS leakage detection

systems inoperable, other than those specified in Action E, the unit be in Hot Shutdown

within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. With the drywell unit coolers condensate flow rate monitoring system

already inoperable, existing TS LCO 3.4.3.1, Action F must be entered when certain TS

surveillance testing is performed on the remaining operable RCS leakage detection

systems. For example, a functional test and channel calibration of the drywell floor drain sump flow monitoring system are per formed once every 31 days and 6 months, respectively. During the performance of these tests, the drywell floor drain sump flow

monitoring system is declared inoperable. As a result, the 12-hour shutdown Action

required by existing TS LCO 3.4.3.1, Action F is entered because of both the drywell unit

coolers condensate flow rate monitoring system and the drywell floor drain sump flow

monitoring system being inoperable concurrently. The proposed changes include a new

7-day Action requirement that provides the ability to perform TS required surveillance testing and repair, if necessary, on the other RCS leakage detection systems, as License Amendment Request Attachment 1 One-Time Changes to TS SR 3.4.3.1 (RCS Leakage Detection Systems) Page 2 of 8 Docket No. 50-353 Evaluation of Proposed Changes

applicable, without being in a 12-hour shutdown Action statement because of the already inoperable drywell unit coolers condensate flow rate monitoring system.

A description and evaluation of the proposed changes are provided in this attachment.

provides the marked-up TS page indicating the proposed changes.

provides the marked-up TS Bases page for information only.

2.0 PROPOSED CHANGE

S The changes requested by this amendment application are described below.

1. Add new TS LCO 3.4.3.1, Action F to read: "With the drywell unit cooler condensate flow rate monitoring system inoperable and one other RCS leakage detection system inoperable, other than the primary containment atmosphere gaseous radioactivity

monitoring system (ACTION E), restore at least one of the leakage detection systems to OPERABLE status within 7 days AND perform a CHANNEL CHECK of the primary

containment atmosphere gaseous radioactivi ty monitoring system (SR 4.4.3.1.a) once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

• " The proposed changes are shown in Attachment 2.

2. Change existing TS LCO 3.4.3.1, Action F to Action G and revise it to read: "With any two or more leakage detection systems inoperable other than ACTIONS E or F

• above, OR with required Actions and associated Completion Time of ACTIONS A, B, C, D, E or F

• not met, be in HOT SHUTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> AND in COLD SHUTDOWN within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />." These proposed changes are shown in

.

3. Add the following footnote to Action F and Action G, as appropriate:

• ACTION F is only effective for the remainder of the current operating cycle (Cycle 10), which is currently scheduled to end in the Spring of 2009, or until the

next shutdown of sufficient duration to allow for drywell unit cooler condensate

flow rate monitoring system repairs, whichever comes first.

4. Revise TS Bases 3/4.4.3.1 to reflect the changes proposed above. These proposed changes are provided in Attachment 3 for information only.

3.0 BACKGROUND

Limits on leakage from the reactor coolant pressure boundary (RCPB) are required so

that appropriate action can be taken before the integrity of the RCPB is impaired.

Leakage detection systems for the RCS are provided to alert the operators when

leakage rates above normal background levels are detected and also to supply

quantitative measurement of leakage rates.

License Amendment Request Attachment 1 One-Time Changes to TS SR 3.4.3.1 (RCS Leakage Detection Systems) Page 3 of 8 Docket No. 50-353 Evaluation of Proposed Changes

Systems for separating the leakage of an identified source from an unidentified source are necessary to provide prompt and quantitat ive information to the operators to permit them to take immediate corrective action. At LGS, leakage from the RCPB inside the

drywell is detected by at least one of four (4) independently monitored variables which

include drywell drain sump level changes over time yielding drain flow rates, and drywell

gaseous radioactivity, drywell unit cooler condensate flow rate and drywell

pressure/temperature levels. The primary means of quantifying leakage in the drywell

are the drywell floor drain sump flow monitoring system for unidentified leakage and the

drywell equipment drain tank flow monitoring system for identified leakage.

The drywell floor drain sump flow monito ring system monitors unidentified leakage collected in the floor drain sump. Unidentified leakage consists of leakage from RCPB

components inside the drywell which are not normally subject to leakage and otherwise

routed to the drywell equipment drain sump. The primary containment floor drain sump

has a transmitter that supplies level indication to the main control room via the plant

monitoring system. The level instrument proc essing unit calculates an average leak rate (gpm) for a given measurement period whic h resets whenever the sump drain valve closes. The level processing unit provides an alarm to the main control room each time

the average leak rate changes by a predetermined value since the last time the alarm

was reset. For the drywell floor drain sump flow monitoring system, the setpoint basis is

a 1 gpm change in unidentified leakage.

In addition to the drywell floor drain sump flow monitoring system described above, the discharge of each sump is monitored by an independent flow element. The measured

flow rate from the flow element is integrated and recorded. A main control room alarm is

also provided to indicate an excessive sump discharge measured via the flow element.

This system is not credited for drywell fl oor drain sump flow monitoring system operability.

The primary containment atmosphere gaseous radioactivity monitoring system continuously monitors the primary contai nment atmosphere for gaseous radioactivity levels. A sudden increase of radioactivity, which may be attributed to RCPB steam or

reactor water leakage, is annunciated in the main control room. The primary

containment atmosphere gaseous radioactivity monitoring system is not capable of

quantifying leakage rates, but is sensitive enough to detect increased leakage rates of 1

gpm within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Larger changes in leakage rates are detected in proportionally

shorter times.

Condensate from the eight drywell unit coolers is routed to the drywell floor drain sump

and is monitored by a series of flow transmitters that provide indication and alarms in the

main control room. The outputs from the flow transmitters are added together by

summing units to provide a total continuous condensate drain flow rate. The high flow

alarm setpoint is based on condensate drain flow rate in excess of 1 gpm over the

currently identified preset leak rate. The drywell unit cooler condensate flow rate

monitoring system serves as an added indicator, but not quantifier, of RCS unidentified

leakage.

License Amendment Request Attachment 1 One-Time Changes to TS SR 3.4.3.1 (RCS Leakage Detection Systems) Page 4 of 8 Docket No. 50-353 Evaluation of Proposed Changes

The drywell temperature and pressure monito ring systems provide an indirect method for detecting RCPB leakage. A temperature and/or pressure rise in the drywell above

normal levels may be indicative of reactor coolant or steam leakage.

4.0 TECHNICAL ANALYSIS

Proposed LGS TS LCO 3.4.3.1, new Action F.

Limerick has four (4) individual RCS leakage detection systems required by TS LCO 3.4.3.1. Currently, the drywell unit cooler condensate flow rate monitoring system is inoperable and cannot be repaired without a unit shutdown. Proposed TS LCO 3.4.3.1, Action F, requires that, with the drywell unit cooler condensate flow rate monitoring

system inoperable and one other RCS leakage detection system inoperable, other than

the primary containment atmosphere gaseous r adioactivity monitoring system (existing TS Action E), at least one of the leakage detection systems be restored to operable

status within 7 days and that a Channel Check of the primary containment atmosphere gaseous radioactivity monitoring system (SR 4.4.3.1.a) be performed once every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. It is recognized that with two RCS leakage detection systems inoperable, the

diversity of the means for detecting RCS leakage is reduced. However, the 7-day

allowed outage time recognizes that other forms of RCS leakage detection are available

and ensures that the plant will not be operated in this degraded configuration for an

extended period of time. As discussed in the Bases to LGS TS 3.4.3.1, the drywell floor

drain sump flow monitoring system, the primary containment atmosphere gaseous

radioactivity monitoring system and the dr ywell unit coolers condensate flow rate monitoring system all have the capability of detecting a change in leakage at a rate of 1

gpm within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> in conformance with Regulatory Guide (RG) 1.45 (Reference 1) while

the primary containment pressure and tem perature monitoring system provides an indirect method for detecting RCPB leakage. Relative to proposed TS LCO 3.4.3.1, Action F, as indicated in the table below, with the drywell unit cooler condensate flow

rate monitoring system inoperable and one other RCS leakage detection system inoperable, the combination of RCS leakage detection systems that remain operable will

always involve at least one RCS leakage detection system that has the capability of

detecting a change in leakage at a rate of 1 gpm within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. In some situations, there

may be two remaining operable RCS leakage detections systems that have this

capability.

The following table summarizes the inoperable combination of RCS leakage detection

systems and the supplementary Action associated with the new proposed Action F.

INOPERABLE OPERABLE ACTION F - SUPPLEMENTARY ACTIONS FD/UC RM/PT Perform a Channel Check of the primary containment atmosphere gaseous radioactivity monitoring system once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. UC/PT FD/RM Perform a Channel Check of the primary containment atmosphere gaseous radioactivity monitoring system once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

FD - Drywell floor drain sump flow monitoring system

RM - Primary containment atmosphere gas eous radioactivity monitoring system UC - Drywell unit coolers condensate flow rate monitoring system

PT - Primary containment pressure and temperature monitoring system License Amendment Request Attachment 1 One-Time Changes to TS SR 3.4.3.1 (RCS Leakage Detection S y stems) Page 5 of 8 Docket No. 50-353 Evaluation of Proposed Changes

In addition, the RCS leakage detection systems at LGS consist of one (1) system to quantify leakage (drywell floor drain sump flow monitoring), three (3) early detection

systems (drywell floor drain sump flow m onitoring, primary containment atmosphere gaseous radioactivity monitoring, and drywell unit cooler condensate flow rate

monitoring) and one (1) indirect leakage detection method (containment press and

temperature). The current TS LCO 3.4.3.1 specifies an Action for each inoperable RCS

leakage detection system. The proposed TS LCO 3.4.3.1, Action F will allow the drywell

unit cooler condensate flow rate monitoring system and one other RCS leakage

detection system to be inoperable; however, the two remaining operable RCS leakage

detection systems would consist of at least one (1) early detection system. For example, the proposed TS LCO 3.4.3.1, Action F will allow the drywell unit cooler condensate flow

rate monitoring system (an early detection sy stem) and the drywell floor drain sump flow monitoring system (which is also an early detection system) to be inoperable. In this case, the remaining operable RCS leakage detection systems would consist of one (1)

early detection system (the primary cont ainment atmosphere gaseous radioactivity monitoring system) and the indirect leakage detection monitor (primary containment pressure and temperature monitoring system).

As indicated in the table above, proposed TS LCO 3.4.3.1, Action F also includes a

supplementary Action. With the drywell unit cooler condensate flow rate monitoring

system inoperable, and either the drywell floor drain sump flow monitoring system or the primary containment pressure and temper ature monitoring system inoperable, then Action F requires that a Channel Check of the primary containment atmosphere gaseous

radioactivity monitoring system be perform ed once every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> rather than once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The increased frequency for performing this supplementary Action makes up

for the loss of the inoperable RCS leakage detection systems. In addition, the frequency

of performing the supplementary Action provides periodic information that is adequate to

detect RCS leakage. This supplementary Acti on is consistent with the supplementary Action described in TS LCO 3.4.3.1, Action C for an inoperable drywell unit cooler

condensate flow rate monitoring syst em and an operable primary containment atmosphere gaseous radioactivity monitoring system.

In addition, as discussed in the Bases for TS LCO 3.4.3.1, although not credited for

operability of the drywell floor drain sump flow monitoring system, the discharge of each

sump is monitored by an independent flow el ement. The measured flow rate from the flow element is integrated and recorded. A main control room alarm is provided to

indicate an excessive sump discharge measured via the flow element. This flow

measurement is not continuous but is measured on a periodic basis when the sump is

drained. Regardless, if the drywell floor dr ain sump flow monitoring system is inoperable in addition to the drywell unit cooler condensate flow rate monitoring system, this

provides an alternative indication of RCS leakage.

Proposed LGS TS LCO 3.4.3.1, new Action G (revised old Action F)

Existing TS LCO 3.4.3.1, Action E and proposed new Action F provide Action

requirements that cover all combinations of the drywell unit cooler condensate flow rate

monitoring system and one other RCS leakage detection system being inoperable. As a result, the new Action G, i.e., the old Action F, is revised to address the condition of any License Amendment Request Attachment 1 One-Time Changes to TS SR 3.4.3.1 (RCS Leakage Detection S y stems) Page 6 of 8 Docket No. 50-353 Evaluation of Proposed Changes

two or more RCS leakage detection systems, other than those specified in TS Actions E or F, being inoperable. Under this condition, the number and diversity of leakage

detection systems has degraded to the point that the plant must be brought to an

operational condition in which the TS LCO does not apply. Also, if any of the required

Actions individually cannot be met in the allotted time period, the plant must be brought

to an operational condition in which the TS LCO does not apply. In this case, the plant

must be brought to Hot Shutdown in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and Cold Shutdown within the next 24

hours.

5.0 REGULATORY ANALYSIS

5.1 No Significant Hazards Consideration

Exelon has evaluated whether or not a significant hazards consideration is involved with

the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

1. Do the proposed changes involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No. The proposed changes continue to maintain an acceptable level

of reactor coolant system (RCS) leakage detection instrumentation required to

support plant operations. The level of RCS leakage detection capability inherent

with the proposed changes will continue to provide acceptable early warning

detection of potential RCS pressure boundary degradation. The proposed

changes do not impact the physical configuration or design function of plant

structures, systems, or components (SSC s) or the manner in which SSCs are operated, modified, tested, or inspected. The proposed changes do not impact

the initiators or assumptions of analyzed events, nor do they impact mitigation of

accidents or transient events. Therefore, the proposed changes do not involve a

significant increase in the probability or consequences of an accident previously

evaluated.

2. Do the proposed changes create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No. The proposed changes only affect systems associated with the

detection of leakage resulting from the degradation of the RCS pressure

boundary. The proposed changes do not alter plant configuration or require that

new plant equipment be installed. The RCS leakage detection systems will

continue to function as designed in all modes of operation. No new accident type

is created as a result of the proposed changes. No new failure mode for any

equipment is created. The proposed changes do not alter assumptions made

about accidents previously evaluated. Therefore, the proposed changes do not

create the possibility of a new or different kind of accident from any accident

previously evaluated.

License Amendment Request Attachment 1 One-Time Changes to TS SR 3.4.3.1 (RCS Leakage Detection S y stems) Page 7 of 8 Docket No. 50-353 Evaluation of Proposed Changes

3. Do the proposed changes involve a significant reduction in a margin of safety? Response: No. The proposed changes do not involve any physical changes to

plant SSCs or the manner in which SSCs are operated, modified, tested, or

inspected. The proposed changes do not involve a change to any safety limits, limiting safety system settings, limiti ng conditions of operation, or design parameters for any SSC. The proposed changes do not impact any safety analysis assumptions and do not involve a change in initial conditions, system

response times, or other parameters affecting an accident analysis. Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

Based on the above, Exelon concludes that the proposed amendment presents no

significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.

5.2 Applicable Regulatory Requirements/Criteria

General Design Criterion 30, "Quality of Reactor Coolant Pressure Boundary," of

Appendix A to 10 CFR Part 50, "General Design Criteria for Nuclear Power Plants,"

(Reference 2) requires that means be provided for detecting and, to the extent practical, identifying the location of the source of reactor coolant leakage. Regulatory Guide (RG)

1.45, "Reactor Coolant Pressure Boundary Leakage Detection Systems," describes

acceptable methods of implementing this requirement with regard to the selection of

leakage detection systems for the reactor coolant pressure boundary.

RG 1.45 specifies that at least three separate detection methods should be employed.

Two of the methods should be sump level/flow monitoring and airborne radioactivity

monitoring. The third method may be unit cooler condensate flow rate monitoring. In

addition, RG 1.45 suggests that temperature or pressure monitoring of the containment

atmosphere be considered as indirect indication of leakage to the containment. At LGS, leakage from the RCPB inside the drywell is detected by at least one of four (4)

independently monitored variables which include drywell drain sump level changes over

time yielding drain flow rates, and drywell gaseous radioactivity, drywell unit cooler

condensate flow rate and drywell pressure/temperature levels. The proposed changes

do not alter plant configuration. The RCS leakage detection systems will continue to

function as designed in all modes of operation. The proposed changes allow the drywell

unit cooler condensate flow rate monitoring system and one other RCS leakage

detection system to be inoperable at one time; however, because of the number and

diversity of leakage detection systems, there remains sufficient instrumentation to

provide early detection of RCS leakage.

In conclusion, based on the considerations discussed above, (1) there is reasonable

assurance that the health and safety of the public will not be endangered by operation in

the proposed manner, (2) such activities will be conducted in compliance with the

Commission's regulations, and (3) the issuance of the amendment will not be inimical to

the common defense and security or to the health and safety of the public.

License Amendment Request Attachment 1 One-Time Changes to TS SR 3.4.3.1 (RCS Leakage Detection S y stems) Page 8 of 8 Docket No. 50-353 Evaluation of Proposed Changes

6.0 ENVIRONMENTAL CONSIDERATION

A review has determined that the proposed amendment would change a requirement

with respect to installation or use of a facility component located within the restricted

area, as defined in 10 CFR 20, or would change an inspection or surveillance

requirement. However, the proposed amendment does not involve (i) a significant

hazards consideration, (ii) a significant change in the types or significant increase in the

amounts of any effluent that may be released offsite, or (iii) a significant increase in

individual or cumulative occupational radiation exposure. Accordingly, the proposed

amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR

51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact

statement or environmental assessment need be prepared in connection with the

proposed amendment.

7.0 REFERENCES

1. Regulatory Guide 1.45, Reactor Coolant Pressure Boundary Leakage Detection Systems, " dated May 1973.

2. 10 CFR 50, Appendix A, General Design Criterion 30, "Quality of Reactor Coolant Pressure Boundary."

ATTACHMENT 2 License Amendment Request Limerick Generating Station, Unit 2 Docket No. 50-353

Proposed One-Time Changes to Techni cal Specifications Section 3.4.3.1 - Reactor Coolant System Leakage Detection Systems Markup of Proposed Technical Specifications Page Unit 2 TS Page 3/4 4-8a

- ACTOR COOLANT SYSTEM EONS (Continued) s With any above.0R with reaui red Actio associated Completion Time of ACTIONS , B, two or moremection systems inoperable other than- in HOT SHUTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> AND in COLD SHUTDOWN-within 3.3.1 The reactor coolant system leakage detection systems shall be demonstrated 2rable by: a. Perform a CHANNEL CHECK of the primary containment atmosphere gaseous radioactivity moni toring system in accordance with the Survei 11 ance Frequency Control Program. b. Perform a CHANNEL FUNCTIONAL TEST or required leakage detection instrumentation in accordance with the Surveil 1 ance Frequency Control Program. This does not apply to containment pressure and temperature monitoring system. C. d. Perform a CHANNEL CALIBRATION of required leakage detection instrumentation in accordance with the Surveillance Frequency Control Program. This does not apply to containment pressure and temperature monitoring system. Monitor primary containment pressure AND primary containment temperature in accordance with the Survei 11 ance Frequency Control Program. LIMERICK - UNIT 2 3/4 4-8a Amendment No. 44.3, 1,47 TS 3.4.3.1 LCO Action Insert F. With the drywell unit cooler condensate flow rate monitoring system inoperable and one other RCS leakage detection system inoperable, other than the primary containment atmosphere gaseous radioactivity monitoring system (ACTION E), restore at least one of the leakage detection systems to OPERABLE status within 7 days AND perform a CHANNEL CHECK of the primary containment atmosphere gaseous radioactivity monitoring system (SR 4.4.3.1.a) once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.*

Footnote

• ACTION F is only effective for the remainder of the current operating cycle (Cycle 10), which is currently scheduled to end in the Spring of 2009, or until the next shutdown of sufficient duration to allow for drywell unit cooler condensate flow rate monitoring system repairs, whichever comes first.

ATTACHMENT 3 License Amendment Request Limerick Generating Station, Unit 2 Docket No. 50-353

Proposed One-Time Changes to Techni cal Specifications Section 3.4.3.1 - Reactor Coolant System Leakage Detection Systems Markup of Proposed Technical Specifications Bases Page Unit 2 TS Page B 3/4 4-3c

REACTOR COOLANT SYSTEM ACTIONS (Continued)

C. With the required primary containment air cooler condensate flow rate monitoring system inoperable, SR 4.4.3.1.a must be performed every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to provide periodic information of activity in the primary containment at a more frequent interval than the routine frequency of every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. information that is adequate to detect leakage and recognizes that other forms of leakage detection are available.

The required ACTION has been clarified to state that the additional survei 11 ance requi rement is not appl icable if the requi red primary containment atmosphere gaseous radioactivity monitoring system is also inoperable.

on inoperable equipment.

In this case, ACTION Statement A. and E. requirements The 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> interval provides periodic Consistent with SR 4.0.3, surveillances are not required to be performed apply 0. With the primary containment pressure and temperature monitoring system inoperable, operation may continue for up to 30 days given the system's indirect capability to detect RCS leakage. However, other more limiting Tech Spec requirements associated with the primary containment pressure/temperature monitoring system will still apply E. With both the primary containment atmosphere gaseous radioactivity monitor and the primary containment air cooler condensate flow rate monitor inoperable, the only means of detecting leakage is the drywell floor drain sump monitor and the drywell pressure/ternperature instrumentation.

This condition does not provide the required diverse means of leakage detection.

The required ACTION is to restore either of the inoperable monitors to OPERABLE status within 30 days to regain the intended leakage detection diversity.

The 30 day Completion Time ensures that the plant will not be operated in a degraded configuration for a lengthy time period. gaseous radioactivity moni tor i s INOPERABLE, Primary c grab samples will be taken and analyzed every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> since qui rements a1 so apply. Time, the plant must be brought to an OPERATIONAL CONDITION in While the primary p of Conditions A, B, C, D5$f E cannot be met within the apply. ithin 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and COLD SHUTDOWN within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Times are reasonable, based on operating experience, to an orderly manner and wi thout chall engi ng plant systems. To achieve this status, the plant must be brought to SURVEILLANCE REQUIREMENTS SR 4.4.3.1.a This SR is for the performance of a CHANNEL CHECK of the required primary containment atmospheric monitoring system. is operating properly.

The check gives reasonable confidence that the channel I LIMERICK - UNIT 2 B 3/4 4-3c Amendment U, 422,147 TS 3.4.3.1 Bases Inserts F. With the drywell unit cooler condensate fl ow rate monitoring system and one other RCS leakage detection system inoperable, other than the primary containment atmosphere gaseous radioactivity monitoring system as described in ACTION E, the required ACTION is to restore either of the inoperable monitors to OPERABLE status within 7 days and to perform a CHANNEL CHECK of the primary containment atmosphere gaseous radioactivity monitoring system once every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The 7-day Completion Time is based on the possibility that the other inoperable leakage detecti on system is the drywell floor drain sump flow monitoring system, which is the primary method for quantifying RCS leakage. The 7-day Completion Time ensures that the plant will not be operated in a degraded configuration for an extended time period. The following table summarizes the inoperable combination of RCS leakage detection systems and the supplementary Action associated with ACTION F

• . INOPERABLE OPERABLE ACTION F - SUPPLEMENTARY ACTIONS FD/UC RM/PT Perform a Channel Check of the primary containment atmosphere gaseous radioactivity monitoring system once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. UC/PT FD/RM Perform a Channel Check of the primary containment atmosphere gaseous radioactivity monitoring system once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

FD - Drywell floor drain sump flow monitoring system RM - Primary containment atmosphere gaseous radioactivity monitoring system UC - Drywell unit coolers condensate flow rate monitoring system

PT - Primary containment pressure and temperature monitoring system The increased frequency for performing this supplementary Action makes up for the loss of the inoperable RCS leakage detection systems. In addition, the frequency of performing the supplementary Action provides periodic information that is adequate to detect RCS leakage.

This supplementary Action is consistent with the supplementary Action described in TS LCO 3.4.3.1, Action C. for an inoperable drywell unit cooler condensate flow rate monitoring system and an operable primary containment atmosphere gaseous radioactivity monitoring system.

G. With any two or more leakage detection systems inoperable, other than those specified in Actions E or F

• , the number and diversity of leakage detection systems is degraded to the point that the plant must be brought to an OPERATIONAL CONDITION in which the LCO does not apply.

Footnote

• ACTION F is only effective for the remainder of the current operating cycle (Cycle 10), which is currently scheduled to end in the Spring of 2009, or until the next shutdown of sufficient duration to allow for drywell unit cooler condensate flow rate monitoring system repairs, whichever comes first.