ML18141A702

Responds to Generic Ltr 83-10D Re Compliance W/Criteria for Resolution of TMI Action Item II.K.3.5.Westinghouse Owners Group Emergency Response Guidelines Based Procedures Will Be Developed in Conjunction W/Control Room Design Review

ML18141A702
Person / Time
Site:	Surry, North Anna, 05000000
Issue date:	06/04/1984
From:	Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Harold Denton, Eisenhut D Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.K.3.05, TASK-TM 202, GL-83-10D, NUDOCS 8406120257
Download: ML18141A702 (3)

Text

e VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261

w. L. STEWART VxoE PRESIDENT NUCLEAR 0PERATrONS June 4, 1984 Mr. Harold R. Denton, Director Serial No. 202 Office of Nuclear Reactor Regulation NO/TAH:acm Attn: Mr. Darrell G. Eisenhut, Director Docket Nos. 50-280 Division of Licensing 50-281 U. S. Nuclear Regulatory Commission 50-338 Washington, D. C. 20555 50-339 License Nos. DPR-32 DPR-37 Gentlemen: NPF-4 NPF-7 VIRGINIA ELECTRIC AND POWER COMPANY RESPONSE TO GENERIC LETTER 83-lOd In our response to Generic Letter 83-lOd, Serial No. 095, April 22, 1983, Vepco presented the plan for demonstrating compliance with the criteria for resolution of TMI Action Plan Requirements Item II.K.3.5. The criteria were established in Generic Letter 83-lOd from Mr. Darrell G. Eisenhut of the Nuclear Regulatory Commission to all Licensees with Westinghouse designed Nuclear Steam Supply Systems dated February 8, 1983. The* submittals which fulfill the established requirements have been transmitted to you by Westinghouse Owners Group (WOG) letters OG-117, dated March 9, 1983 and OG-110, dated December 1, 1983.

Section I of the attachment to Generic Letter 83-lOd discusses "Pump Operation Criteria Which Can Result in RCP Trip During Transients and Accidents".

Subsection 1 of Section I presents guidelines for establishing setpoints for RCP Trip. The WOG response to this section of Generic Letter 83-lOd is contained in Revision 1 to the WOG Emergency Response Guidelines, which has been issued to member utilities. Our implementation of these procedµres will be in accordance with our Response to Supplement 1 to NUREG 0737, Serial No.

006, April 15, 1983 and our Procedures Generation Package, Serial No. 006A, submitted July 1, 1983.

In our response to GL83-10d, Serial No. 095, April 22, 1983, Vepco stated that the RCP trip criteria would be incorporated into the current Emergency Procedures without waiting for Rev 1 of the WOG ERGs. Since that time we have

.... begun our Control Room Design Review (CRDR) and found that it would be best to develop the WOG Rev 1 ERG based procedures in conjunction with the CRDR Task Analysis and Verification and Validation programs. We anticipate completing these tasks and developing the Rev 1 based procedures by late 1984 or early 1985. Our current internal schedule has the Validation Process completed in December, 1984. Because of the proximity of the Rev 1 upgrade, our desire to integrate the Supplement 1 to NUREG 0737 items wherever practicable, and the need to minimize piecemeal procedure changes, we now intend to incorporate the RCP trip criteria into the Rev 1 modification to our Emergency Procedures.

8406120257 840604 \

i PDR ADOCK 05000280 F PDR

e VIRGINIA ELECTRIC AND POWER COMPANY TO Harold R. Denton

• Page 2 The RCP Trip Criteria being adopted for the North Anna and Surry Power Station plant specific procedures assures RCP trip for all losses of primary coolant where RCP trip is considered necessary while permitting RCP operation to continue during most non-LOCA accidents. These include steam generator tube rupture events up to the design basis double-ended tube rupture. The generic applicability of the RCP trip criteria selected has been documented by the Westinghouse Owners Group Report entitled, "Evaluation of Alternate RCP Trip Criteria", which has been submitted to the NRC for review in WOG letter OG-110.

The Westinghouse Owners Group has also submitted to the NRC, via WOG letter OG-117, the report entitled "Justification of Manual RCP Trip for Small Break LOCA Events". As stated above, these submittals completed the WOG documentation comprising a generic reply to NRC Generic Letter 83-lOd.

Subsection 2 of Section I of the attachment to Generic Letter 83-lOd provides guidance for justification of manual RCP trip. Subsection 2a requires that compliance with 10CFR50.46 be demonstrated in an Appendix K small break LOCA analysis given that the RCPs are tripped two minutes after the onset of reactor conditions corresponding to the RCP trip setpoint. The WOG has generically verified, in the OG-117 submittal, that predicted LOCA transients presuming the two minute delayed RCP trip are nearly identical to those presented in Safety Analysis Reports utilizing the WFLASH Evaluation model.

Thus, the Updated Final Safety Analysis Reports for the North Anna and Surry Power Stations demonstrate compliance with the Subsection 2a guidelines.

The WOG has also performed "most probable, best estimate" WFLASH analyses to r demonstrate, generically, compliance with the guidelines presented in Subsection 2b of Section I of the attachment to NRC Generic Letter 83-lOd.

These analyses identify that the minimum time available for operator action for the complete range of LOCA break sizes exceeds the value contained in N660; they show that reactor coolant pumps may be tripped at any time during a LOCA event without resulting in excessive clad temperatures. The applicability information presented in the generic report affirms the applicability of this best estimate analyses to the North Anna and Surry Power Stations. Therefore, in combination with the Subsection 2a justification cited above, the best estimate analyses justify that manual RCP trip is acceptable for the North Anna and Surry Power Stations when RCP trip setpoints, consistent with Revision 1 to the Emergency Response Guidelines, are in use. Furthermore, the generic report demonstrates that no additional contingency emergency procedures are required to address the scenarios which may follow a missed RCP trip setpoint.

In summary, the generic information presented by the Westinghouse Owners Group in the reports entitled "Evaluation of Alternate RCP Trip Criteria" and "Justification of Manual RCP Trip for Small Break LOCA Events" provides the response to NRC Generic Letter 83-lOd for the North Anna and Surry Power

r i e

VIRGINIA ELECTRIC AND POWER COMPANY TO Harold R. Denton

• Page 3 Stations. The implementation of Revision 1 to the Emergency Response Guidelines in the plant-specific procedures with an appropriate RCP trip setpoint specified resolves all issues associated with automatic tripping of the reactor coolant pumps.

Please contact us if additional information is required.

v~~*

W. L. Stewart cc: Mr. James P. O'Reilly Regional Administrator Region II USNRC Suite 2900 101 Marietta St.

Atlanta, Georgia 30303 Mr. Steven A. Varga, Chief Operating Reactors Branch No. 1 Division of Licensing Mr. James R. Miller, Chief Operating Reactors Branch No. 3 Division of Licensing Mr. J. Don Neighbors Surry Project Manager Mailstop 438 7920 Norfolk Ave.

USNRC Bethesdi, Maryland 20014 Mr. Leon B. Engle North Anna Project Manager Mailstop 428 7920 Norfolk Ave.

USNRC Bethesda, Maryland 20014 Mr. D. J. Burke NRC Resident Inspector Surry Power Station Mr. M. W. Branch NRC Resident Inspector North Anna Power Station