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Operating Corporation Update Response to Requested Information Part 2 of Generic Letter 2004-02; Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors
	ML061580076
Person / Time
Site:	Wolf Creek
Issue date:	05/31/2006
From:	Hedges S; Wolf Creek
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	GL-04-002, WO 06-0028
	Download: ML061580076 (7)
	v • d • e

NUCLEAR OPERATING CORPORATION May 31, 2006 Stephen E. Hedges Vice President Operations and Plant Manager WO 06-0028 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

Reference:

1) Letter ET 05-0018, dated August 31, 2005, from Terry J.

Garrett, WCNOC, to USNRC

2) NRC letter dated March 28, 2006, from Catherine Haney, NRC, to Holders of Licenses for Pressurized-Water Reactors

Subject:

Docket No. 50-482: Wolf Creek Nuclear Operating Corporation Update Response to Requested Information Part 2 of Generic Letter 2004-02: uPotential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized-Water Reactors" Gentlemen:

This letter provides the Wolf Creek Nuclear Operating Corporation (WCNOC) updated response to Nuclear Regulatory Commission (NRC) Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized-Water Reactors."

The NRC issued Generic Letter 2004-02 on September 13, 2004 to i) request that addressees perform an evaluation of the Emergency Core Cooling System (ECCS) and Containment Spray System (CSS) recirculation functions in light of the information provided in the generic letter and, if appropriate, take additional actions to ensure system function, and ii)require addressees to provide the NRC a written response in accordance with 10 CFR 50.54(f).

Reference 2 transmitted the NRC's alternative approach for responding to the NRC request for additional information letter on Generic Letter 2004-02. The agreed altemative to the 60 day response is that for those units completing their strainer modifications in 2006, information needed to fully address Generic Letter 2004-02 will be provided to the staff by December 31, 2006.

P.O. Box 411 / Burlington, KS 66839 / Phone: (620) 364-8831 An Equal Opportunity Employer M/F/HCNVET

WO 06-0028 Page 2 of 2 Reference 1 provided the available information requested in Generic Letter 2004-02 as of August 31, 2005 and committed to update that information by June 1, 2006. To address the generic letter and -associated commitments, -the activities described below have taken place.

Specific commitments are addressed in Attachment I. During the week of March 13, 2006, mock up strainer head loss testing was performed. Analysis of the results is ongoing. Activities are proceeding as described in !Reference I and are outlined'in Attachment I of this submittal.

Specifically, WCNOC plans to install new containment recirculation sump strainers to increase the available (i.e., submerged) strainer area from less than 400 square feet currently available to an expected area of approximately 6400 square feet. Any additional information needed to fully address the generic letter will be provided to the staff by December 31, 2006 as

- established in the request for additional information schedule provided in Reference 2. -

This letter transmits changes in WCNOC's regulatory commitments contained in Reference 1.

The commitment changes are being -submitted in accordance With guidance provided by industry document NEI 99-04, "Guidelines for Managing NRC Commitment Changes," as endorsed in Regulatory Issues Summary 00-017, "Managing Regulatory Commitments Made by Power Reactor Licensees to the NRC Staff." Attachment I lists the WCNOC commitments contained in this letter. Commitments contained in this letter supercede those previously contained in Reference 1.

If you have anyquestions concerning this matter, please contact me at (620) 364-4190, or Mr.

Kevin Moles at (620) 364-4126.

Very truly yours, t en E. Hedges SEH/rlt Attachment I - Updated List of Commitments cc: J. N. Donohew (NRC), wla -

W. B. Jones (NRC),w/a B. S. Mallett (NRC), w/a Senior Resident Inspector (NRC), w/a

STATE OF KANSAS )

) Ss COUNTY OF COFFEY )

Stephen E. Hedges, of lawful age, being first duly sworn upon oath says that he is Vice President Operations and Plant Manager of Wolf Creek has read the foregoing document and knows the contents Nuclear Operating Corporation; that he same for and on behalf of said Corporation with full thereof; that he has executed the power and authority to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.

Stephe H..Hges

-Vie Presoidt Operations and Plant Manager SUBSCRIBED and sworn to before me thisI.f day of M'a 3 , 2006.

Notary Public Expiration Date

Attachment I to WO 06-0028 Page 1 of 4 UPDATED LIST OF COMMITMENTS The following table identifies those actions originally committed to by Wolf Creek Nuclear Operating Corporation in Reference 1. The table provides a status update and revised commitment due dates. Any other statements in this letter are provided for information purposes and are not considered to be regulatory commitments. Please direct questions regarding these commitments to Mr. Kevin Moles, Manager Regulatory Affairs at Wolf Creek Generating Station, (620) 364-4126.

Regulatory Commitment Current Status Due Date

1. The following corrective action activities will be completed: December 31, 2006

a. Using WCAP-16406-P, evaluate the effects of debris-laden a. Initial downstream evaluations have been fluid on systems and components downstream of the performed; however, refinements are containment emergency sump strainers during the ECCS being pursued using test data and input recirculation phase of design basis accidents. from PWROG/NRC discussions concerning nuclear fuel.

b. Using NEI 04-07, evaluate the effects of design basis accident b. Upstream evaluations have been conditions on the ability of structures, systems and performed and will be included in the components upstream of the containment emergency sump Westinghouse team analysis summary strainers to mitigate the consequences of the analyzed report, Item 4 of this table.

accidents.

c. Using the results of containment coatings testing, resolve the c. Zone of influence testing has been unverified assumption in the NEI 04-07 debris generation performed and a draft report was issued in calculation of a 5 pipe diameter zone of influence for qualified May 2006.

containment coatings.

2. Submit an update to information contained in WCNOC's response The analyses are proceeding and refinements December 31, 2006 to Generic Letter 2004-02 Requested Information Item 2. are being pursued. The update of information contained in Requested Information Item 2 will be provided after completion of Item 4 of this table.

Attachment I to WO 06-0028 Page 2 of 4 Regulatory Commitment Current Status I Due Date

3. The following evaluations and testing will be completed:

December 31, 2006

a. Perform industry chemical effects testing on the replacement a. Industry chemical effects test have been containment emergency sump strainers. completed.

b. Using NEI 04-07, perform a debris generation calculation for b. The debris generation calculation has the analyzed design basis accidents. been performed and included in the Westinghouse team analysis summary report, Item 4 of this table.

c. Using NEI 04-07, perform a debris transport calculation for the c. The debris transport calculation has analyzed design basis accidents. been performed and will be included in the Westinghouse team analysis summary report, Item 4 of this table.

d. Evaluate the impact of chemical effects on containment d. WCAP 16530-NP guidance was used as emergency sump strainer head loss during design basis part of the strainer performance testing accident conditions. performed during the week of March 13, 2006.

e. Complete head loss testing of the replacement containment e. Head loss testing including provisions for emergency sump strainer. chemical effects, were performed during the week of March 13, 2006.

f. Confirm that the available NPSH of the replacement f. The strainer performance test report is in containment emergency sump strainers during design basis progress and will be used in the accident conditions is in excess of the required NPSH. determination of adequate NPSH.

g. Perform a structural analysis of the replacement containment g. The structural analysis of the emergency sump strainers during design basis accident replacement strainers is proceeding as conditions. scheduled.

Attachment I to WO 06-0028 Page 3 of 4

4. Complete the final site acceptance review of the Westinghouse Several of the items contained in the final December 31, 2006 evaluation team analysis summary report. report have been completed but the final report will not be issued until all items are completed.

5. The following items will be completed: Prior to restart from Refueling Outage 15

a. Replace the containment emergency recirculation sump a. Activities are proceeding as scheduled. (Fall 2006) strainers.

b. Install containment debris barriers and modify containment b. Debris barriers are currently planned debris interceptors if required. for installation during Refueling Outage

15. Use of debris interceptors is dependant on the refinements mentioned in Item 1.a. of this table.

c. Modify safety injection system components, if required, based c. Implementation of potential on the results of the downstream effects evaluation, modification to the safety injection system is dependant on the refinements mentioned in Item 1.a. of this table.

6. Remove the containment spray system pump cyclone separators, Removal of containment spray system (CSS) December 31, 2007 if required, based on the results of the downstream effects pump cyclone separators is dependent on the evaluation, results of the downstream effects evaluation, Item 1.a. of this table

Attachment I to WO 06-0028 Page 4 of 4

7. The following programs and controls will be implemented to December 31, 2007 control sources of debris.

a. Implement changes to programmatic controls for (1) design a. These programmatic controls are change process procedures, (2) containment entry and established and implemented.

material control procedures, (3) clearance orders procedures, (4) work request procedures, And (5) scaffold construction and use procedures to control the introduction of potential sources of debris into containment.

b. Implement a containment coatings assessment program. b. A preventive maintenance program has been established and implementation will begin in Refueling Outage 15 (Fall 2006).

c. Implement a containment latent debris assessment program. c. A Preventive Maintenance program has been established and implementation will begin in Refueling Outaae 15 (Fall 2006).

8. Implement changes to inspection processes for the installed sump Activities are proceeding as scheduled. December 31, 2007 strainers to ensure they support the associated analyses of design basis accidents.

9. Implement all plant modifications and related administrative Activities are proceeding as scheduled. December 31, 2007 controls that support the NEI 04-07 analysis package.