Text

Supplemental Response to NRC Generic Letter 2008-01, Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems
	ML090490833
Person / Time
Site:	Callaway
Issue date:	02/04/2009
From:	Sandbothe S; AmerenUE
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	GL-08-001, TAC MD7806, ULNRC-05590
	Download: ML090490833 (15)
	v • d • e

AmerenUE PO Box 620 Callaway Plant Fulton, MO 65251 February 4, 2009 ULNRC-05590 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop P1-137 Washington, DC 20555-0001 WAmmeren 10 CFR 50.54(f)

UE Ladies and Gentlemen:

DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.

FACILITY OPERATING LICENSE NPF-30 SUPPLEMENTAL RESPONSE TO NRC GENERIC LETTER 2008-01, "MANAGING GAS ACCUMULATION IN EMERGENCY CORE COOLING, DECAY HEAT REMOVAL, AND CONTAINMENT SPRAY SYSTEMS" (TAC NO. MD7806)

References:

1. NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008

2. ULNRC-05504, "Three-Month Response to NRC Generic Letter 2008-01, 'Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems,"'

dated April 10, 2008

3. NRC Letter from M.C. Thadani to A. C. Heflin re: Callaway Plant, Unit 1, "Generic Letter 2008-0 1, 'Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems,' Proposed Alternative Course of Action," dated September 18, 2008

4. ULNRC-05551, "Response to NRC Generic Letter 2008-01,

'Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems,"' dated October 13, 2008 NRC Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment'Spray Systems," dated a subsidiary of Ameren Corporation

ULNRC-05590 February 4, 2009 Page 2 January 11, 2008 (Reference 1) was issued pursuant to the requirements of 10 CFR Part 50.54(f) to request information from licensees regarding how they protect certain safety systems from the accumulation of air, nitrogen or other gases that could cause the systems to become inoperable. The GL requested licensees evaluate their emergency core cooling, decay heat removal, and containment spray systems in order to determine how their licensing basis, design, testing and corrective actions ensure that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified. Specifically, the NRC requested licensees to provide the following information:

1. A description of the results of evaluations that were performed pursuant to the above requested actions. This description should provide sufficient information to demonstrate that [the licensee is] or will be in compliance with the quality assurance criteria in Sections III, V, XI, XVI, and XVII of Appendix B to 10 CFR Part 50 and the licensing basis and operating license, as those requirements apply to subject systems;

2. A description of all corrective actions, including plant, programmatic, procedure, and licensing basis modifications that the licensee determined were necessary to assure compliance with these regulations, and

3. A statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule.

By letter dated April 10, 2008 (Reference 2) AmerenUE provided a 3-month response to the GL, indicating that not all of the required plant walkdowns and evaluations would be completed by the October 11, 2008 deadline. AmerenUE's April 10, 2008 letter was subsequently acknowledged by the NRC in a letter to AmerenUE dated September 18, 2008 (Reference 3). AmerenUE's 9-month response for Callaway Plant Unit 1 was provided in Reference 4. As indicated in the 9-month response, AmerenUE committed to providing a supplemental response within 90 days of the completion of the Refuel 16 outage which concluded on November 7, 2008. This letter provides the supplemental response (which satisfies Commitment 1 in Enclosure II of Reference 4) as provided in Enclosure 1.

The information provided in Enclosure 1 reflects completion of the remaining walkdowns that needed to be completed pursuant to GL 2008-01 and which were scheduled to be completed during Callaway's fall refueling outage (RF 16). In most cases, the walkdowns were completed with no discrepancies identified between the plant configuration and the associated isometric drawings. Level checks were performed as part of the walkdowns, and some localized high spots were identified and evaluated. Vent valves were verified to be in their expected locations and no new

ULNRC-05590 February 4, 2009 Page 3 vent valves were required to be installed based on these walkdowns. Modifications involving the installation of two new vent locations identified during the GL evaluation were implemented. All adverse conditions identified during the plant walkdowns and evaluations were documented and resolved in accordance with Callaway's Corrective Action Program.

In summary, based on the evaluations and inspections performed, AmerenUE has concluded that the ECCS, RHR, and CS systems are capable of performing their specified safety functions and that the systems are in compliance with their licensing basis with respect to the concerns outlined in GL 2008-01. The only remaining corrective action involves the resolution of the definition of "full" in Technical Specification Surveillance Requirement 3.5.2.3 and the corresponding updates to the Final Safety Analysis Report. Ameren UE committed in its 9-month response to pursue resolution of this issue based on the Technical Specification Task Force generic traveler. This item is tracked within Callaway's Corrective Action Program.

This response is submitted in accordance with 10 CFR 50.4. This letter contains no new commitments.

If there are any questions or if additional information is needed, please contact Mr. Scott Maglio at (573) 676-8719 or Mr. Tom Elwood at (573) 676-6479.

I declare under penalty of perjury that the foregoing is true and correct.

Sincerely, Executed on: e2 -C)-

Scott Sandbothe Manager, Regulatory Affairs DER/nls

Enclosure:

I- Supplemental Response to NRC Generic Letter 2008-'01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems"

ULNRC-05590 February 4, 2009 Page 4 cc: U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852 Mr. Elmo E. Collins, Jr.

Regional Administrator U.S. Nuclear Regulatory Commission Region IV 612 E . Lamar Blvd., Suite 400 Arlington, TX 76011-4125 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Mohan C. Thadani (2 copies)

Licensing Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop O-8G14 Washington, DC 20555-2738

ULNRC-05590 February 4, 2009 Page 5 Index and send hardcopy to QA File A160.0761 Hardcopy:

Certrec Corporation 4200 South Hulen, Suite 630 Fort Worth, TX 76109 (Certrec receives ALL attachments as long as they are non-safeguards and may be publicly disclosed.)

Electronic distribution for the following can be made via Responses and Reports ULNRC Distribution:

A. C. Heflin F. M. Diya T. E. Herrmann D. W. Neterer L. S. Sandbothe J. T. Patterson T. D. Hermann M. A. McLachlan K. A. Mills G. L. Bradley P. J. McKenna T. A. Moser S. M. Maglio T. B. Elwood D. E. Rickard S. L. Gallagher T. L. Woodward (NSRB)

Mr. Ron Reynolds, Director (SEMA)

Mr. Edward Gray, Senior REP Planner (SEMA)

Mr. John Campbell, REP Planner (SEMA)

Ms. Diane M. Hooper (WCNOC)

Mr. Tim Hope (TXU)

Mr. Scott Bauer (PVNGS)

Mr. Stan Ketelsen (PG&E)

Mr. Wayne Harrison (STPNOC)

Mr. Loyd Wright (SONGS)

Mr. John O'Neill (Pillsbury Winthrop Shaw Pittman LLP)

Mr. Floyd Gilzow (DNR)

ULNRC-05590 Enclosure I Page 1 of 10 Supplemental Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" NRC Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008 was issued to request information from licensees regarding compliance with current licensing and design basis requirements, applicable regulatory requirements, and control measures in place for maintaining compliance for the following systems:

Emergency Core Cooling System (ECCS),

Decay Heat Removal (DHR), and

Containment Spray System (CSS).

The NRC requested that each addressee evaluate its ECCS, DHR system, and CSS licensing basis, design, testing, and corrective actions to ensure that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified.

The NRC requested that each addressee provide the following information:

1. A description of the results of evaluations that were performed pursuant to the above requested actions. This description should provide sufficient information to demonstrate that the licensee is or will be in compliance with the quality assurance criteria in Sections III, V, XI, XVI, and XVII of Appendix B to 10 CFR Part 50 and the licensing basis and operating license, as those requirements apply to subject systems;

2. A description of all corrective actions, including plant, programmatic, procedure, and licensing basis modifications that the licensee determined were necessary to assure compliance with these regulations, and

3. A statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule.

The above requested information was provided to the NRC in AmerenUE's 9-month response (Reference 8). This supplemental response provides information addressing items specified in AmerenUE's 9-month response as not being complete, and includes additional information gained from RF16. This response augments the information previously provided, and therefore, none of the descriptions, conclusions, or completed actions that did not change are repeated here.

ULNRC-05590 Enclosure I Page 2 of 10 The following information is provided in this supplemental response:

a) A description of the results of evaluations or walkdowns completed subsequent to the 9-month response, most of which were completed during the refueling outage (RF16) conducted at Callaway in the fall.

b) A description of any additional corrective actions determined necessary to assure system operability and compliance with license basis requirements.

c) A summary of the status of corrective actions identified as incomplete at the time of the 9-month response, as well as identification of any changes in the identified corrective actions and the basis for those changes.

A. Results of Evaluations or Walkdowns Completed Subsequent to the 9-Month Response Walkdowns Identified as Incomplete in Status and Findings the 9-Month Response The High Head Centrifugal Charging (BG) Complete. High Head Safety Injection (BG) system piping located in the Auxiliary and system piping was inspected from the RWST Containment Buildings will be surveyed/laser through the centrifugal charging pumps (CCPs) scanned by the completion of refuel outage to the SI system via the Boron Injection Header RF16 which is currently scheduled to begin up to the bioshield wall for the cold leg piping.

October 11, 2008. After review of the The walkdowns were completed with no survey/laser scan data, plant personnel will discrepancies identified between the current evaluate additional actions needed to address plant configuration and the isometrics. All the any localized high spots. This piping could not vent valves identified on the isometrics were be accessed due to operability, safety and also present in the field. The piping runs (i.e.

radiological considerations prior to the refuel elevation changes) in the field were also in outage scheduled to begin on October 11, agreement with the isometrics. The second 2008. part of the "walkdown" verification involved level checks (i.e. determining piping slope) for the piping within the scope of work. As expected, some localized high spots were identified. None of these localized high spots required installation of vent valves. For piping with localized high spots, the normal full flow alignment is being credited for sweeping away any potential minor voiding present in the line.

In accordance with plant procedures, any subsequent draining -of the line would prompt engineering personnel to UT the localized high spots in the drained and refilled pipe segment.

Reference Action 5.1 of Reference 6.

The RHR (EJ) system piping located in the Complete. RHR (EJ) system piping from the Auxiliary Building will be surveyed/laser RWST through the RHR pumps up to the scanned by the completion of refuel outage bioshield wall for the hot and cold leg piping RF16 which is currently scheduled to beain d V was inspected. The piggyback lines to the

ULNRC-05590 Enclosure I Page 3 of 10 Walkdowns Identified as Incomplete in Status and Findings the 9-Month Response October 11, 2008. The RHR system piping CCPs and the safety injection pumps (SIPs) located inside containment will be walked-down were also a part of this inspection. The and surveyed/laser scanned during RF16. walkdowns were completed with no discrepancies identified between the current plant configuration and the isometrics. All the vent valves identified on the isometrics were also present in the field. The piping runs (i.e.

elevation changes) in the field were also in agreement with the isometrics. The second part of the "walkdown" verification involved level checks (i.e. determining piping slope) for the piping within the scope of work. As expected, some localized high spots were identified. None of these localized high spots required installation of vent valves. The full flow alignment used during normal shutdown cooling is credited for sweeping any potential minor voiding present in the line. In accordance with plant procedures, any subsequent draining of the line would prompt engineering personnel to UT the localized high spots in the drained and refilled pipe segment.

Reference Job 08005266 and Action 5.2 of Reference 6.

Complete a level check of the remainder of the Complete. All Safety Injection (EM) piping Safety Injection (EM) system piping in the walkdowns were completed during RF16.

Auxiliary Building and piping in the Intermediate Head Safety Injection piping from Containment Building which is within the scope the RWST system through the SI pumps up to of this generic letter evaluation. This piping the bioshield wall for the hot and cold leg piping could not be accessed due to operability, was inspected. The piggyback lines from the safety and radiological considerations prior to CCPs and the RHR system were also a part of the refuel outage scheduled to begin on this scope of work. The SI pumps crossover October 11, 2008. piping was also included in this scope of work.

The walkdowns were completed with no discrepancies identified between the current plant configuration and the isometrics. All the vent valves identified on the isometrics were also present in the field. The piping runs (i.e.

elevation changes) in the field were also in agreement with the isometrics. The second part of the "walkdown" verification involved level checks (i.e. determining piping slope) for the piping within the scope of work. One localized high spot was identified in the Boron Injection Header upstream of EMHV8801B.

Surveillance procedure OSP-ZZ-00003 (Attachments 1, 2, 3) was revised to establish periodic venting requirements. Void acceptance was developed and incorporated into the procedure to establish operability limits for voiding at this location. The localized high spot did not require installation of a vent valve.

ULNRC-05590 Enclosure I Page 4 of 10 Walkdowns Identified as Incomplete in Status and Findings the 9-Month Response E__

The full flow alignment used during "piggyback" pump surveillance testing is credited for sweeping any potential minor voiding present in the line. In accordance with plant procedures, any subsequent draining of the line would prompt engineering personnel to UT the localized high spots in the drained and refilled pipe segment. Reference Job 08005239 and Actions 4.1.3, 4.1.5, and 5.3 of Reference 6.

i The scope of the Containment Spray (EN) Complete. The Containment Spray (EN) system piping walkdown from the containment system was inspected from the RWST through sump to the RWST supply tee will be the CS pumps to the spray header isolation conducted during the upcoming refuel outage valves. The walkdowns were completed with RF16 scheduled to commence on October 11, no discrepancies identified between the current 2008. plant configuration and the isometrics. All the vent valves identified on the isometrics were also present in the field. The piping runs (i.e.

elevation changes) in the field were also in agreement with the isometrics. The second part of the "walkdown" verification involved level checks (i.e. determining piping slope) for the piping within the scope of work. There were no localized high spots identified as a result of the level checks. Consistent with the drawing review conducted for the 9-month response, one locationin each train was identified to have the potential of having voiding present. The location between the containment sump isolation valve and the downstream check valve was an area where voiding could result due to the current plant configuration. The water source (Refueling Water Storage Tank (RWST)) would not be able to completely fill the piping between the two valves due to the check valve's presence.

During RF16, fill and vent valves were installed at these two locations to allow for filling of the piping between the sump isolation valve and the downstream check valve (See section on completed Corrective Actions below).

Reference Action 5.4 of Reference 6.

I The scope of the Accumulator Safety Injection Complete. The Accumulator safety injection (EP) System portion of the Callaway ECCS to (EP) piping from each SI Accumulator to the be walked down consists of the discharge associated RCS Cold Leg was walked-down piping from each Safety Injection Accumulator and visually inspected for its "as-built" (SI ACC) to the corresponding connections to configuration conformance to plant isometric each RCS Cold Leg. All portions of these lines drawings M-23EP01 and M-23EP02 The are inside containment, uninsulated up to the walkdown verified that vents are in the proper upstream RCS check valves (EM8956A-D), location along horizontal (nominal) runs and and will not be radiologically and physically circumference of the pipe; that piping is sloped

ULNRC-05590 Enclosure I Page 5 of 10 Walkdowns Identified as Incomplete in Status and Findings the 9-Month Response accessible until the upcoming refueling outage (where required) in the proper direction; and (RF-1 6) scheduled to begin on October 11, that horizontal (nominal) runs of pipe do not 2008. contain visually obvious local highpoints. The EP system piping "as-built" configuration conforms to plant isometric drawings.

Reference Action 5.5 of Reference 6.

B. Description of Additional Corrective Actions Determined Necessary to Assure System Operability and Compliance with License Basis Requirements No additional changes were identified as being needed to the design basis documents. AmerenUE will follow industry initiatives regarding void migration and the effects of void ingestion on pumps. Depending on the results of those initiatives, AmerenUE may make changes to its design basis documentation in the future.

AmerenUE will continue to participate in industry initiatives to improve the understanding of gas accumulation issues and development of technical information on which to base design and operating practices. At the time of this submittal, those programs are not finalized and no final time frame for issue resolution is provided. AmerenUE currently does not require and does not anticipate the need for any of the industry initiatives in order to support system operability.

The Technical Specification Bases for Surveillance Requirement (SR) 3.5.2.3 requires revision. The SR Bases will be revised to make clear its applicability to both the suction and discharge sides of the pumps as well as define that the SR's requirement to be "full of water" means sufficiently full to ensure operability of the system given the considerations outlined in the GL. -The FSAR description for ECCS systems in section 6.3.2.2 repeats the TS Bases discussion and will be revised to include the same description as the revised TS Bases. These changes are on hold pending NRC resolution of allowable mechanisms for making the changes. This allows the changes to be made in accordance with an approved process, made only one time, and helps ensure that the FSAR, TS and TS Bases all contain consistent requirements. These changes were placed on hold following receipt of a communication from the Nuclear Energy Institute (NEI) on August 28, 2008 indicating that the NRC Office of General Council (OGC) had determined that 10 CFR 50.59 could not be used to make the needed TS Bases changes.

TS improvements are being addressed by the Technical Specifications Task Force (TSTF) to provide an approved TSTF Traveler for making changes to individual licensee's TS related to the potential for unacceptable gas

ULNRC-05590 Enclosure I Page 6 of 10 accumulation. The development of the TSTF Traveler relies on the results of the evaluations of a large number of licensees to address the various plant designs.

AmerenUE is continuing to support the industry and NEI Gas Accumulation Management Team activities regarding the resolution of generic TS changes via the TSTF Traveler process. After NRC approval of the Traveler, AmerenUE will evaluate its applicability to the Callaway plant, and evaluate adopting the Traveler to either supplement or replace the current TS requirements.

Actions 4.1.8 and 4.1.9 of CAR 200800298 (Reference 6) track the implementation of these corrective actions within Callaway's Corrective Action Program. Resolution of this issue via the TSTF process was provided as Commitment 2 in Enclosure 11of the 9-month response (Reference 8).

Two FSAR enhancements are proposed. The FSAR description of ECCS System Reliability included in FSAR section 6.3.2.5 will be revised to include a description of the methods used to verify that the piping is sufficiently full of water to ensure the functional capability of the system. Similarly, the FSAR description for Containment Spray System Operational Testing included in FSAR section 6.2.2.1.4 will be revised to include a description of the methods used to verify that the piping is sufficiently full of water to ensure the functional capability of the system. The proposed FSAR enhancements increase the level of detail in the document to help future plant personnel understand the practices employed to monitor for gas accumulation in the ECCS and CS systems. Although this information is inherent in the plant procedures, its placement in the FSAR provides a more holistic presentation of the activities used to ensure the functional capability of the systems. The procedures are already subject to 10 CFR 50, Appendix B requirements, thus making this an enhancement.

Actions 4.1.10 and 4.1.11 of Reference 6 track the implementation of these enhancements which will coincide with the FSAR changes made as part of the resolution of the SR 3.5.2.3 TS Bases wording changes (described above).

C. A Summary of the Status of Incomplete Corrective Actions at the Time of the 9-Month Response, Identification of Any Changes in the Identified Corrective Actions, and the Basis for Those Changes The following table provides a summary of the corrective actions identified in the 9-month response to the GL as not having been completed. The current status of the corrective action is provided in the right-hand column.

Actions Not Complete at time of Completion Date Identified in Status at the time of the 9-month Reason for the the 9-Month Response and the Supplemental Response Action Basis for the Completion Date Response Install vent valve and Address section of Included in Refuel 16 which Complete. The vent bypass line between piping not capable of started on October 11, 2008. valve and bypass line ENVO002 and being vented This was the first available were installed using ENHV0001 opportunity. Job 08004424 in

ULNRC-05590 Enclosure I Page 7 of 10 Actions Not Complete at time of Completion Date Identified in Status at the time of the 9-month Reason for the the 9-Month Response and the Supplemental Response Action Basis for the Completion Date Response accordance with MP 08-0016 FCN 01.

Completed on 10/31/2008 during RF16 Install vent valve and Address section of Included in Refuel 16 which Complete. The vent bypass line between piping not capable of started on October 11, 2008. valve and bypass line ENV0008 and being vented This was the first available were installed using ENHV0007 opportunity. Job 08004426 in accordance with MP 08-0016 FCN 01.

Completed on 11/2/2008 during RF16.

(1) Establish and Revision was ongoing and would Complete.

Revision of provide specific be completed by the point in Procedure OTN-EJ-OTN-EJ-00002, venting criteria for time when the system was 00002 Addenda 01, Residual Heat each vent location returned to service during the 02, 03, and 04 were Removal System.

(i.e., vent for 1 to RF16 refueling outage which revised as specified.

2 minutes after started on October 11, 2008. Procedures were obtaining a solid issued on 11/19/2008 stream of water). prior to system (2) Establish and restoration at the provide specific conclusion of RF16.

venting criteria for (Action 4.1.6 of instrument lines Reference 6) for each instrument loop in the drained portion of the system.

Tech Spec Bases for The current language Incomplete. Awaiting TS improvements are being Surveillance is subject to industry resolution of Requirement (SR) addressed by the Technical interpretation and the TSTF. This item Specifications Task Force 3.5.2.3 requires misinterpretation and is tracked by (TSTF) to provide an approved revision. The SR does not explicitly Action 4.1.8 of CAR TSTF Traveler for making Bases will be revised provide the expected 200800298 changes to individual licensee's to make clear the scope of the (Reference 6) in the TS related to the potential for applicability to both surveillance. Corrective Action unacceptable gas accumulation.

the suction and Program. Resolution The development of the TSTF discharge sides of the of this issue was Traveler relies on the results of pumps as well as identified as the evaluations of a large define that the SR's Commitment 2 in number of licensees to address requirement to be "full Enclosure II, "List of the various plant designs.

of water" means Commitments," in the AmerenUE is continuing to sufficiently full to 9-month response support the industry and NEI ensure operability of submittal the system given the Gas Accumulation Management (Reference 8).

Team activities regarding the considerations resolution of generic TS

ULNRC-05590 Enclosure I Page 8 of 10 Actions Not Complete at time of Completion Date Identified in Status at the time of the 9-month Reason for the the 9-Month Response and the Supplemental Response Action Basis for the Completion Date Response outlined in the GL. changes via the TSTF Traveler process. After NRC approval of the Traveler, AmerenUE will evaluate its applicability to the Callaway Plant Unit 1, and evaluate adopting the Traveler to either supplement or replace the current TS requirements.

The FSAR description The current language The FSAR changes will be Incomplete. Awaiting for ECCS systems in is subject to accomplished in conjunction with industry resolution of section 6.3.2.2 will be interpretation and the resolution of the wording of the TSTF. This item revised to include the misinterpretation and TS SR 3.5.2.3 and/or associated is tracked by same description as does not explicitly Bases. Thus, these changes Action 4.1.9 of CAR the Tech Spec Bases. provide the expected are contingent the resolution of 200800298 scope of the the TSTF initiative discussed (Reference 6) in the surveillance. This above. Corrective Action action also ensures Program. Resolution consistency between of this issue was license basis identified as documents. Commitment 2 in Enclosure II, "List of Commitments," in the 9-month response submittal (Reference 8).

Items affecting or potentially affecting the license or design basis and physical configuration of the ECCS, RHR and CSS systems were previously evaluated to determine their impact on Operability. Those evaluations were performed in accordance with procedure APA-ZZ-00500, Correction Action Program.

CONCLUSION AmerenUE has evaluated those Callaway Plant systems that perform the functions described in the GL and has concluded that those systems are capable of performing their intended specified safety functions, and are in conformance with our commitments to the applicable General Design Criteria (GDC), as stated in the Callaway Plant Unit 1 FSAR.

With the exception of the changes to the TS Bases and corresponding changes to the FSAR, all other corrective actions are complete. Revision of the license basis documents is on hold pending the outcome of the NRC / NEI Technical Specification Task Force (TSTF) resolution of the changes needed to the Technical Specifications and associated Bases. In Enclosure II of AmerenUE's

ULNRC-05590 Enclosure I Page 9 of 10 9-month response (Reference 8), the following commitment was provided to resolve the TS Bases and corresponding FSAR deficiencies:

COMMITMENT Due Date / Event

2) AmerenUE will monitor the industry resolution One (1) year following of the gas accumulation TS issues and submit a NRC approval of the license amendment request, as appropriate, within 1 TSTF or CLIIP Notice of year following NRC approval of the TSTF Traveler Availability.

or the CLIIP Notice of Availability.

That commitment remains in place and is being tracked by Actions 4.1.8, 4.1.9, 4.1.10 and 4.1.11 of CAR 200800298 (Reference 6) within the Corrective Action Program. No new commitments are made in this supplemental response.

ULNRC-05590 Enclosure I Page 10 of 10

References:

1. NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008.

(ML072910759)

2. NRC Generic Letter 1988-17, "Loss of Decay Heat Removal,"

dated October 17, 1988.

3. NRC Generic Letter 97-04, "Assurance of Sufficient Net Positive Suction Head for Emergency Core Cooling and Containment Heat Removal Pumps," dated October 7, 1997.

4. NUREG-0897, "Containment Emergency Sump Performance-Technical Findings Related to USI A-43," dated October 1985.

5. ULNRC-05504, Three-Month Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," (TAC No. MD7806) dated April 10, 2008.

(ML081130717)

6. Callaway Action Request (CAR) 200800298, "Generic Letter 2008-01 Response."

7. NRC Letter from M.C. Thadani to A. C. Heflin dated September 18, 2008 re: Callaway Plant, Unit 1, "Generic Letter 2008-01,

'Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems,'

Proposed Alternate Course of Action" (TAC No. MD7806)

(ML082180683).

8. ULNRC-05551, Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," (TAC No. MD7806) dated October 13, 2008. (ML082960429)