ML20046C336

Forwards Response to GL 93-04, Rod Control Failure & Withdrawal of Rod Control Cluster Assemblies. Util Participating W/Wog to Evaluate Significance of Salem Event. Util Expects to Complete Response by End of 90-day Period

ML20046C336
Person / Time
Site:	Farley
Issue date:	08/04/1993
From:	Dennis Morey SOUTHERN NUCLEAR OPERATING CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-93-04, GL-93-4, NUDOCS 9308100158
Download: ML20046C336 (4)

Text

Southern Nuc'ev Operatng Cornpany 7 's Post O'fce Box 1295 Birmingham, Alab3M3 35201 1205 Tc4 hone 205 86%000 n

Southern Nudear Operating Company August 4, 1993 """""*""*"

Docket Nos. 50-348 10 CFR 50.54(f) 50-364 U.S. Nuclear Regulatory Commission ATrN: Document Control Desk Washington, DC 20555 Joseph M. Farley Nuclear Plant Response to Generic Letter 93-04 Rod Control System Failure and Withdrawal of Rod Control Cluster Assemblies Gentlemen:

On June 21,1993 the NRC issued Generic Letter 93-04, Rod Control System Failure and Withdrawal of Rod Control Cluster Assemblies,10 CFR 50.54(f)." The generic letter requires licensees with Westinghouse Rod Control Systems to respond within 45 days by providing an assessment of whether or not the plant licensing basis is satisfied with regard to the requirements for system response to a single failure in the Rod Control System, i.e., General Design Criterion 25. If the assessment indicates the licensing basis is not satisfied, then each licensee must describe short-term compensatory actions, consistent with the guidance in the generic letter, and within 90 days provide a plan and schedule for long-term resolution. However, subsequent correspondence between the NRC and the Westinghouse Owners Group (WOG), dated July 26,1993, resulted in schedular relief for the requirement to determine compliance with the licensing basis. As such, the portion of the Southern Nuclear Operating Company (SNC) response pertaining to the assessment of the Farley Nuclear Plant (FNP) Rod Control System licensing basis will be included with the 90-day response.

Southern Nuclear Operating Company is participating with the WOG to evaluate the significance of the Salem event relative to Westinghouse full length, solid state Rod Control Systems. In accordance with the schedule for this program as described to the NRC during its meeting with the WOG representatives on July 9,1993, SNC expects to complete the response to the generic letter by the end of the 90-day period.

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l The attachment summarizes the compensatory actions taken by Farley Nuclear Plant i in response to the Salem Rod Control System failure event.

As requested by NRC letter dated July 26,1993, the results of the WOG generic safety analysis program to evaluate a series of asymmetric rod withdrawal cases are applicable to Farley Nuclear Plant. The preliminary results of the generic analyses and the Farley-specific application demonstrate that Departure from Nucleate Boiling (DNB) does not occur for the worst-case asymmetric rod withdrawal. A summary of this generic safety analysis program and its applicability will be reported in WCAP-13803, " Generic Assessment of Asymmetric Rod Cluster Control Assembly Withdrawal," which the'  :

WOG is scheduled to submit to the NRC by August 5,1993.

Respectfully submitted, SOUTIIERN NUCLEAR OPERATING COMPANY W1 Dave Morey

??h%f Vice President .

Farley Project  !

MGE\sar:GL9304A.MGE l Attachment SWORN TO AND SUBSCRIBED BEFORE ME cc: Mr. S. D. Ebneter Tills & DAY OFO nry el ,1993.

Mr. T. A. Reed 0 Mr. G. F. Maxwell Cyd ma fnho Notary Public My Commission expires:1-aff to l

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A1TACHMENT FARLEY NUCLEAR PLANT RESPONSE TO NRC GENERIC LETTER 93 04 COMPENSATORY ACTIONS Comnensatory Actions 1

Section 1(b) of the generic letter requested a description of compensatory short-term l actions that were taken or will be taken if the assessment concludes the plant licensing basis is not being met. The results of the assessment of compliance with the licensing basis will not be available until the submittal of the 90-day response. In accordance with the July 26, 1993 NRC letter to the WOG, the following discussion describes compensatory actions that have been taken. This response addresses the three areas l of compensatory short-term actions identified in Generic Letter 93-04.

1. Additional Cautions or Modifications to Surveillance and Preventive Maintenance Procedures.  !

Based on current SNC knowledge of the Rod Control System and the Rod Position l Indication Systems, the surveillance and preventive maintenance programs currently in place at FNP assure the Rod Control System is operable. If the results of the WOG investigations identify previously unrecognized potential single failures that could result  ;

in operation of the Rod Control System and the associated Rod Control Cluster  !

Assemblies outside of the licensing basis, SNC will evaluate the new information to  !

determine if additional or different surveillances are necessary. Presently, the Rod Control System and Rod Position Indication Systems are operable, and there is no need for increased frequency of surveillance or additional surveillance for the purpose of i increasing confidence in system reliability. However, in response to Westinghouse Nuclear Safety Advisory Letter 93-007, FNP enhanced certain precautions and instructions in the Rod Control System and Rod Position Indication Systems surveillance procedures and developed a new functional test procedure for the control j room rod deviation annunciator. )

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2. Additional Administrative Controls for Plant Startuo And Power O_oeration.

The existing administrative controls in the FNP unit operating procedures are adequate for plant startup, shutdown, and power operations. SNC is also aware of the additional administrative controls to require startup by dilution that were implemented at the Salem Plant, and SNC does not anticipate the need for additional administrative controls for plant startup or power operation at FNP. However, if the results of the WOG investigations indicate additional administrative restrictions are required, the controls will be developed and implemented based on the results of the WOG program.

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U. S. Nuclear Regulatog Comraission Page 2 Attachment At FNP the Rod Control System is operated manually during reactor startup and shutdown. During at-power operations the Rod Control System is normally maintained in the manual mode of control; however, the operator can place the system in automatic when deemed necessay. This manner of operation, in conjunction with control room rod position indications and associated annunciators, assures that the operators will be aware of any abnormal rod movement and can quickly terminate inappropriate control rod responses. In addition, FNP Technical Specifications require all full length rods to be operable and positioned within 12 steps of their group step counter position.

3. AdditionalInstructions and Training to Heighten Operator Awareness of Potential Rod Control System Failure and to Guide Ooerator Resoonse in the Event of a Rod

_ Control System Malfunction.

FNP has included information concerning the Salem rod withdrawal event with the required reading for each licensed operator. The Salem event will also be included in operator retraining. These actions re-emphasize the importance of verifying proper rod movement and the potential for unexpected control rod responses, which are inherent elements in the existing FNP licensed operator initial training and re-training programs.