ML20129E395

Discusses Task to Update PRA Results on Five Lwrs.Site Visit by Sandia Requested on 850722-26 to Obtain Current Info on Risk Important Hardware & Procedure Mods

ML20129E395
Person / Time
Site:	Peach Bottom, Grand Gulf, Sequoyah, Surry, Zion, 05000000
Issue date:	06/28/1985
From:	Ernst M NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
To:	Boyer V PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
References
NUDOCS 8507160806
Download: ML20129E395 (5)

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Dear Hr. Boyer:

The Office of !!uclear Regulatory Research of the Nuclear Regulatory Coanission (HRC) is engaged in a task to update the probabilistic risk assessnent (PRA) results on five U.S. LVRs. These plants are Surry, Peach Bottom, Sequoyah, Grand Gulf and Zion, and the task is limited to accident sequer.ces resulting from internal initiators. This task will provide part of an information base to be used by NRR to interact with IDCOR in their development of a proposed nothodology for resolving severe accident issues for plants without PRAs, and to assist in developing a regulatory position on the appropriate role that risk insights should play in the regulation of nuclear power.

I appreciate very much your voluntary offer to permit our contractor (Sandia National Laboratories--SNL) to conduct a 5-day familiarization visit at your plant for approximately six people. This visit will permit a more realistic evaluation of your plant, including obtaining up-to-date information on any risk-important hardware and procedure modifications that have taken place since the PRA on your plant was completed.

Such a realistic evaluation is crucial to the process of drawing accurate, plant-specific perspectives on plant risk ar.d the principal contributors to that risk. The desired dates for this visit are July 22-26, 1985.

Our contractor will be interacting with your plant personnel on this plant familiarization process. The person at SNL responsible for overall mana of the five-plant reassessments is Mr. Frederick T. Harper (505-846-1975)gement . The contractor's team leader for your plant is Mr. Alan Kolaczkowski, Science Applications International Corporation, (505-247-8787). I would appreciate your naming a central point of corporate contact within your organization.

Also, I need the name of the plant contact for day-to-day interactions. If you could provide these names by telephone, I would appreciate it greatly. Comu-nications between the tcan leader and apprcpriate plant personnel should be as direct as possible to facilitate information exchange. However, I would like to be inforned of any nafor probicas that might arise that potentially could affect the quality of the work or the timeliness of its completion.

The plant familiarization process involves several aspects:

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NRC FORM 318 (10 80) NRCM 0240 OFFICIAL RECORD COPY

11r. Vincent S. Dover 2

1. The teaa vill need access to selected PaIDs, cicoentary diagrams and ener-gency operating precedures. A list of itens that will be needed is included as Enclosure 1. It would help the toan considerably if they were able to get some of these diacrans and procedures prior to the plant visit. The tonn will be in touch with the plant to discuss these needs.

2. The visit will include a walk through and discussions with selected engi-neers and operators. Enclosure 2 characterizes the type of personnel that the tcan will need to talk to. Again, the toan will discuss their specific needs with the plant.

3. Exauples of the types of questions that will be asked are provided as Enclosure 3. The tean will provide a list of specific questions prior to the plant visit.

4. The teon will need a contir.uing infornal comunicatw .3 channel with the plant after the visit to answer quick turnaround questions.

5. After the analyses are conpleted (3 or 4 conths after the plant visit), a revisit will be scheduled to confirn those plant features and procedures that appear to be nest inportant to risk.

The above identifics the ainirun needs to provide reasonable assurance that the team uses the proper information in the analyses. If you wish to provide even mre support to this project to ensure as realistic an assessocnt of your plant as possible in the limited tine available, we would certainiv be agreeabic.

For example, it would be very useful to have a knculedgeable engineer or op2 rations person spend a coupla of weeks with the teaa at Albuquerque, New raxico to provide pronpt, first-hand support to the enalysts.

Thank you again for your cooperation. The result of the plant visit will clearly be inportant to the accuracy, quality, and realisn of the analyses and will definitely have a subscquent potential irepact on rcgulation. tfc look forward to working with ycu on this de s ding task.

Sincerely,

/S/

!!alcolm L. Ernst, Deputy Director Division of Risk Analysis and Operations Office of !!uclear Regulatory Research

Enclosures:

As stated cc: Fred Harper, SNL Tony Eng, IRC 4/

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Ifr. Vincent S. Boyer 3 Distribution:

RES Central File R-2912.01.01 CIRC /CifR0!!

RRB Subject / Reading TEng Reading PBaranowsky Reading GGurdick Reading liErnst FGillespie Dross R!linogue

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Enclosure 1 Procedures and Diagrams Necessary for Peach Bottom Analysis

• Procedures

1. Loss of Station Power

2. Station Blackout

3. Loss of One AC Bus (safety only) 4160 volt

4. Loss of One DC Bus

5. Loss of Power Conversion System (loss of feedwater, condenser vacuum, ...)

6. Turbine Trip

7. Loss of Cooling Water (RBCCW, ESWS, HPSWS, ...)

8. Loss of One 120 VAC Vital Bus

9. Loss of Instrument Air

10. Inadvertent SRV Opening

11. MSIV Closure Event

12. Containment Venting

13. LOCA Event

14. Any other specific procedures / guidelines impacting the plant's specific implementation of the EPG's

15. Maintenance / test (human reliability expert will elaborate)

Elementary Wiring Diagrams (one-lines and/or schematics)

1. AC/DC Distribution System

2. Emergency AC (including DC power, air...for diesels)

3. For systems that we need P& ids except HVAC, Instrument Air, PCS Piping and Instrumentation Diagrams and Functional Control Diagrams

1. NSSS Instrumentation

2. Residual Heat Removal (including Low Pressure Coolant Injection)

3. High Pressure Coolant Injection /High Pressure Core Spray

4. Reactor Core Isolation Cooling System

5. Low Pressure Core Spray System

6. Automatic Depressurization System

7. Control Rod Drive System

8. Standby Liquid Control

9. Service Water Systems (RBCCW, ESWS, HPSWS ...)

10. HVAC Systems that support systems above as well as electric power

11. Instrument Air

12. PCS (from Steam to Feedwater)

List of Post-TMI Modifications (and post PRA)

Layout Drawings--Reactor Building and Control Building (Only to determine accessibility to areas for recovery and potential comon modes from a HVAC point of view.)

• Additional request by our human reliability and data experts may follow.

Enclosure 2 Plant Personnel that We Need to Meet with During Plant Visit System engineers Instrumentation and electrical engineers T&M personnel Operators Mair.tenance Personnel Anyone utility recomends to answer types of questions listed in Enclosure 3 for systems of interest.

Enclosure 3 Types of Questions to be Addressed on Plant Visit Will focus on verification of:

General system layout Specific component dependencies (power by bus, cooling water, air,

...)

Loads--particularly for support systems (power, air, cooling water, HVAC ...)

Success criteria under different conditions Actuation specifics--(what automatically starts system, what stops or isolates system, what is normally running, what is normally standby, what can be manually controlled from control room, what is locally controlled?

Timing considerations (e.g., How long can component run without cooling? How long do batteries last without charging?...)

Are there other success paths not known to us?

Maintenance / operational tendencies--(stagger tests, preventive maintenance, specifics of system operation ...)

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