ML20128M021
| ML20128M021 | |
| 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: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NUDOCS 8507110530 | |
| Download: ML20128M021 (6) | |
Text
,
p
\\~
i BES Files k & f/.}. N 0l
~
l St.bj ect File 5 0-y
. nsk 00 -
~-~-
Ecserch Ec'lEt 30 *
~-~~
g gg g FINUc-
~~'
- E ";No-D;cket 30 -
-~i Rule:nakinG UC-
~!
lir. William L. Stewart other L
Vice President for Nuclear Operations soturn IGC-na 1
Virginia Power t a gts, ye s__,Mo____
j
~
One James River Plaza P. O. Box 26666 Richmond, Virginia 23261
Dear tir. Stewart:
The Office of Nuclear Regulatory Research of the Nuclear Regulatory Coanission (NRC) is engaged in a task to updato the probabilistic risk assessment (PRA) results on five U.S. LURs.
These plants are Surry, Peach Botton, Sequoyah, Grand Gulf and Zion, and the task is limited to accident sequences resulting from internal initiators.
This task will provide part of an infomation base to be used by NRR to interact with IDCOR in their development of a proposed nethodology 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 nucicar power.
I appreciate very much your voluntary offer to pemit our contractor (Sandia National Laboratories--SNL) to conduct a 5-day familiarization visit at your plant for approximately six people.
This visit will pemit a nore realistic evaluation of your plant, including obtaining up-to-date infomation on any risk-important hardware and procedure modifications that have taken olace since the PRA on your plant was completed. Such a realistic evaluation i= crucial to the process of drawing accurate, plant-specific perspectives on plant risk and the principal contributors to that risk. As discussed with Tom Shaub by tele-phone, the desired dates for this visit are July 15-19, 1985.
Our contractor will be interacting with your plant personnel on this plant familiarization process. The person at SNL responsibic for overall mana of the five-plant reassessments is !!r. Frederick T. Harper (505-846-1975)gement The contractor's team leaders for your plant are Messrs. Jon Young and Bob Bertuccio, Energy Incorporated (206-854-0080).
As I understand it, the central point of corporate contact within your organization is Mr. Shaub (804-771-3700), and the plant contact for day-to-day interactions is Doug Rickeard (804-357-3184, ext. 288).
Comunications between the tcan leader and appropriate plant per-sonnel should be as direct as possible to facilitate infomation exchange.
However, I would like to be infomed of any major prob 1 cms that night arise that potentially could affect the quality of the work or the tineliness of its cocpletion.
The plant familiarization process involves several aspects:
1.
The team will need access to selected P5 ids, elementary diagrans and emer-gency operating procedures.
A list of items that will be needed is l
8507110530 850628
.u PDR ADOCM 05000277 P
.m>
..{..
.g.
NRCFORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY j
fir. Ifillian L. Stewart 2
included as Enclosure 1.
It would help the team considerably if they were able to get sonc of these diagrans and procedures prior to the plant visit.
The team 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 cperators. Enclosure 2 characterizes the type of personnel that the tean will need to talk to. Again, the team will discuss their specific needs with the plant.
3.
Examples of the types of questions that will be asked are provided as.
The tcan will provide a list of specific cuestions prior to the plant visit.
4.
The team will need a continuing infornal ccnnunications channel with the plant after the visit to answer quick turnaround questions.
S.
After the analyses are ccmpleted (3 or 4 nonths after the plant visit), a revisit will be scheduled to confirn those plant features and procedures that appear to be nost inportant to risk.
The above identifics the minimum needs to provide reasonable assurance that the teca uses the proper inferrntion in the analyses.
If you wish to provide even more support to this project to ensure as realistic an assesse nt of your plant as possible in the linited tine available, us would certainly be agreeable.
For exenple, it would be very useTul to have a knculedgeable engineer or operations pcrson spend a couple of weeks with the tean at Seattle,Ifashington to provide prompt, first-hand support to the analysts.
Thank you again for your cooperation.
The result of the plant visit will clearly be inportant to the accuracy, qunlity, and realism of the analyses and vill definitely have a subsequent potential irapact on regulation.
tle lock forward to working with you on this denanding task.
Sincerely,
)-
tialcolm L. Ernst, Deputy Director Divisien of itisk Analysis and Operations Office of liuclear Regulatory Research
Enclosures:
As stated cc: Too Shaub, Virginia Power Doug Rickcard, Virginia Pouer Fred Harper, SNL Tony Eng,!!RC d
,,,U Ag:pp RE
[.,q WR
$ "= > TEng,: p,17,,,,,KrM,,,,,,
o^>..?ft (f.5
.gss 1
n
lir. Willian L. Stewart 3
Distribution:
RES Central File R-2912.01.01 CIRC /Cl!RON RRB Subject / Reading TEng Reading PBaranowsky Reading GEurdick Reading MErnst FGillespia Dross PJ11nogue H. Thompson T. Speis D. !!cighbors R. Vollncr fl. Grace, Region II D. Burke, Region II PDR Local PDR wn~4 DATE)
NHC FORM 318 (10 80) NRCM O240 OFFICIAL RECORD COPY
Procedures and Diagrams Necessary for Surry Analysis
- I Procedures for the Following Events 1.
Loss of Station Power 2.
Station Blackout 3.
Loss of One AC Safety Bus (4160 V) 4.
Loss of One DC Bus 5.
Loss of Main Feedwater (l1FW) 6.
Loss of MFW and Auxiliary Feedwater (AFW) at One Unit (including procedures for feed and bleed or cross-connect of AFW between Units 1 and 2) 7.
Turbine Trip 8.
Loss of Component Cooling Water 9.
Loss of Charging Pump Cooling Water System
- 10. Low Pressurizer Water Level
- 11. Loss of One 120 VAC Vital Bus
- 12. SIAS Actuation
- 13. Low or High Reactor Coolant System Pressure
- 14. Secondary Blowdown
- 15. T&M (Human reliability expert will elaborate.)
Elementary Wiring Diagrams 1.
AC/DC Distribution System 2.
Emergency AC (including DC power supply for diesel generator start) 3.
SIAS 4.
Consequence Limiting System Simplified Logic Diagrams 1.
Consequence Limiting System 2.
SIAS 3.
Diesel Generator Load Sequencers 4.
AFW Initiation Piping and Instrumentation Diagrams 1.
NSSS including PORVs/ Block Valves 2.
Emergency Core Cooling Systems (LPI + HPI + ACC) 4.
Containment Recirculation Spray 6.
SWS 7.
Charging Pump Cooling System
- Additional requests by our human reliability and data experts may follow.
2 8.
MFW 9.
- 10. Main Steam
- 11. Chemical and Volume Control System
- 12. Component Cooling Water System
- 13. Auxiliary Building Heating, Ventilation, and Air Conditioning (HVAC)
- 14. Turbine Building HVAC
- 15. Circulating Water System Layout Drawings 1.
Reactor Building 2.
Auxiliary Building 3.
Turbine Building List of Post-THI and Post-PRA Modifications at Surry
Plant Personnel that We Need to Meet with During Plant Visit System engineers Instrumentation and electrical engineers T&M personnel Operators Maintenance Personnel Anyone utility recomends to answer types of questions listed in
- for systems of interest.
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...)
-