ML20211P705

Forwards Response to Request for Addl Info Re B&W Owners Group I&C Committee Preliminary Integrated Control Sys (ICS) Evaluation List.Loss of ICS/non-nuclear Instrumentation Procedures Will Be Submitted by 861231

ML20211P705
Person / Time
Site:	Rancho Seco
Issue date:	12/11/1986
From:	Julie Ward SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Miraglia F Office of Nuclear Reactor Regulation
References
JEW-86-933, TAC-61635, NUDOCS 8612190124
Download: ML20211P705 (6)

Text

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esuun SACRAMENTO MUNICIPAL UTILITY DISTRICT O P. O. Box 15830, Sacramento CA 95852-1830,(916) 452-3211 AN ELECTRIC SYSTEM SERVING THE HEART OF CALIFORNIA nansuuhar 11, 1986 JEN 86-933 Director of Nuclear Reactor Regulation Attention: Frank J. Miraglia Jr., Director Division of PHR Licensing-B U. S. Nuclear Regulatory o m ianian Washington, D.C. 20555 Docket 50-312 Rancho Seco Nuclear Generating Station Unit Number 1 DIS 7RICT RESPCHSE TO NRC REQUEST FOR INFORMATION - B&W OWNERS GROUP OCHEITEE l

Dear Mr. Miraglia:

During Settamhar 9 - 11, an NRC Technical Team reviewed the District's j ICS/NNI modification program, and requested certain information regarding the District's activities on the B&WOG, I&C Ctsanittee.

In early Septamhar, the B&WOG g arr= d.ed a preliminary ICS evaluation list to the NRC staff. The NRC Team requested the district to address the B&WOG ICS list as follows: (1) indicate whether the item applies to l Rancho Seco, and (2) briefly state how the District is addressing the

! applicable item. The attachment contains the District's respcnse.

l During -t%_=nt telephone conversatims, the District indicated it would send to the NRC staff for review, copies of.the Rancho Seco Ioss of ICS/NNI g -witres. Because Rancho Seco staff is still revising the l

prnmachives, the District will submit the approved prorwhtres by C+We 31, 1986.-

l If you have any further questions, please feel free to contact Ray Ashley, our Manager of Licensing.

Sincerely, 7

s 7

' s J . Ward Difputy General Manager, Nuclear Attachment oc: Sydney Miner, NRC - Bethesda Tony D'Angelo, NRC - Rancho Seco 8612190124 861211 PDR ADOCK 05000312 IL Ig p PDR RANCHO SECO NUCLEAR GENERATING STATION O 14440 Twin Cities Road, Herald, CA 95638 9799;(209) 333-2935

Frank Miraglia, Jr. December 11, 1986 JEi!86-933 bc: W. K. Lathan J. E. Ward K. Perkins/G. Coward R. L. Ashley D. Poole/B. Croley/T. Tucker D. Gillispie/G. Cranston L. Fossua/J. Shetler S. Knight R. Colombo P. G. Delezenski G. C. Andognini Fourth Floor Files Licensing Files (MS 37)

RIC Files (MS 203)

Plaza 50 Files JEW:GVC:WCM:JW:LTC/lt NRC002(E3NRC)

DISTRICT RESPONSE TO B&WOG PRELIMINARY ICS EVALUATION LIST The B&W Owner Group I&C Committee presented a preliminary Integrated Control System (ICS) evaluation list to the NRC in Septenber 1986.

Since the B&WOG categorized the evaluation list as preliminary and subject to revision, the District's response must also be considered prelimi na ry. However, the Rancho Seco Restart Report ard Action Plan specifically identify the modifications the District intends to complete prior to restart.

The following contains the B&WOG identified item (underlined) and (a) whether the item applies to Rancho Seco and (b) a brief response on how the District is addressing the issue:

I. DESIGN PROBLEMS

l. Control Functions Outside of Non-Safety Systems a) Applies to Rancho Seco b) With the installation of the Rancho Seco EFIC system, Auxiliary Feedwater ( AFW) control and Abnospheric Dump Valve (ADV) control will be renoved fran the ICS.

2. Reliable Poder Source a) Applies to Rancho Seco b) The District has implenented changes that make the poder source more reliable than originally configured. For example, the ICS and Non-Nuclear Instrunentation (NNI) have redundant class II AC and DC sources. External loads are fused while autamitic bus transfer and reliable AC are provided. The AC power is supplied from battery backed sources.

NRCRPT2(Mis 2) ,

3. Loss of All Systen Power (LOP) a) Applies to Rancho Seco b) Although loss of ICS or NNI power is readily apparent, planned modifications increase the infomation available to the operator (e.g. Failure Alanns, Breaker Labels, ABT History Infonnation).

In addition to the above actions to increase infonnation to the operator, the District is investigating the follwing actions to improve reliability:

Fusing Coordination Study Higher Rated DC Pwer Supplies Rewiring of the Power Supply Monitor Sensing Lines

4. Mid-Scale Failure on Loss of Power a) Applies to Rancho Seco b) As an interim measure, the District has labeled all ICS (and NNI) indications in the Control Rom. Emergency Operating Procedures and training instruct the operators to use alternate indication in the event of loss of ICS (or NNI) pwer.

In addition, the District is addressing the issue of mid-scale failure of instrunentation in conjunction with the B&WOG I&C Cemittee.

5. Actuated Equipment Postion on Loss of Pwer a) Applies to Rancho Seco b) As addressed in problen 1, control of heat removal will be thru the EFIC system. In addition, to insure that the ICS on loss of ICS pwer will not prevent the plant fran going to a known safe state, the TBVs will be controlled by an alternate Class II pwer source, while the Main Feedwater Pumps (MFPs) will be tripped, by Class II i nstrumentation. On loss of NNI power, ICS will be tripped. The failure modes of RC makeup control, Reactor Coolant (RC) letdown control and RC punp seal injection control have been analyzed and found to be acceptable.

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6. Input Signals on Loss of Power a) Applies to Rancho Seco b) The District is studying the feasibility of separating NNI X and NNI Y and eliminating NNI Z power for the next refueling outage. However, with the modification of tripping ICS on loss of NNI, the plant will go to a known safe state on loss of NNI X, Y or Z power.

7. Restoration of Power-(ROP) a) Applies to Rancho Seco b) The District has developed procedures and training that direct operators on the appropriate actions for restoration of power. In addition, the District intends to install analog menory modules for all hand / auto stations to ensure predictability of R0P positions of these components. Although the District is attempting to install the modules prior to restart, procurenent schedules may preclude installation until the next refueling outage.

8. Input Sensor / Signal Reliability a) Applies to Rancho Seco b) The District is addressing the concern of autanatic selection of valid input signals in conjunction with the B&WOG I&C Conmittee.

9. Systen Simplification a) Applies to Rancho Seco b) Although unused hardware has not been a problen at Rancho Seco, the District currently plans on removing unused haniware during the next refueling outage.

10. Control Improvenents a) Applies to Rancho Seco b) The District is evaluating additional recommendations to further enhance the reliability of the control portions of the systen. This evaluation includes a review of past studies, as well as work currently underway by the B&WOG.

The District is canbining these BWOG reconmendations into its overall plan and improvenent program.

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II.. PROGRAMATIC PROBLEMS

1. Preventive Maintenance a) Applies to Rancho Seco b) Rancho Seco has procedures for ICS and NNI maintenance acti vities. The District is developing additional procedures, as well as enhancenents to the PM program, and considers this an ongoing process.

2. Systen Tuning a) Applies to Rancho Seco b) The District is currently revising its ICS tuning program and will tune the ICS under the revised program during resta rt.

3. Diagnostics a) Applies to Rancho Seco Continuous on-line monitoring of the ICS is not available at Rancho Seco. Hmever, the District is using a history of base line data at various power levels to diagnose ICS perfonnance.

4. Configuration Managenent a) Applies to Rancho Seco b) Vendor drawings origirally included in the instruction manuals are not updated and are used for infonnation only. Rancho Seco controlled drawings however, are revised and maintained.

Instruction books that contain product descriptions, trouble shooting and calibration procedures are updated ard controlled through the Technical Library,

5. Trai ni ng/ Qualification I a) Applies to Rancho Seco i b) The District is developing a "part task" ICS trainer and an ICS/NNI training program for engineers. The District uses the proper wirewrapping tools and all I&C technicians have attended training on soldering equipment given by l PACE, the equipment manufacturer.

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