ML19209C480
| ML19209C480 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 09/28/1979 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Proffitt W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NUDOCS 7910150632 | |
| Download: ML19209C480 (7) | |
Text
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UNITED STATES E')'
h NUCLEAR REGULATORY COMMISSION
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WASHINGTON, D. C. 20555
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September 28, 1979 Docket Nos. 50-338 50-339 Mr. W. L. Proffitt Senior Vice President - Power Virginia Electric and Power Company Post Office Box 26666 Richmond, Virginia 23261
Dear Mr. Proffitt:
During a meeting with you the morning of September 26, 1979, we reviewed with you a number of areas where we expected to require additional infor-mation from you concerning the safety injection event at North Anna Unit 1 on S.eptember 25, 1979.
Please provide written responses to the enclosed information requests. This information should be provided as soon as the necessary work can be done by your staff but no later than 30 days prior to your planned return to power from the current plant outage, which we understand you are scheduling for about 12 weeks from now.
It is expected that any actions you take will be fully reflected in the design and procedures to be implemented on North Anna Unit 2.
Sincerely, p
h&YOU
/
A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors
Enclosure:
Request for Infonnation cc: w/ enclosure See next page 1134 318 7 91015 0 5 3E
,3
Mr. W. L. Proffitt September 28, 1979 Virginia Electric and Power Company cc: Mr. Anthony Gambardella Mr. Aichael S. K'idd Office of the Attorney General V. S. Nuclear Regulatory Cnaission 11 South 12th Street - Room 308 P. O. Box 128 Richmond, Virginia 23219 Spotsylvania, Virginia 22553 Richard M. Foster, Esquire Director, Technical Assessrent Divisic Office of Radiation Procrans (AW-459) 1230 A Pearl Street Denver, Colorado 80203 U. S. Environmental Protection Agency Crystal Itall #2 flichael W. Maupin, Esquire Arlington, Virginia 20460 Hunton, Williams, Gay and Gibson U. S. Environmental Protection P. O. Box 1535 Richmond, Virginia 23212 Regicq III Office ATTN:
EIS C0ORDINATOR Mrs. June Allen Curtis Building 412 Owens Drive 6th and Walnut Streets Huntsville, Alabama 35801 Philadelphia, Pennsylvania 19106 fir. James Torson Alderman Library Manuscripts Department 501 Leroy Socorro, New Mexico 87801 University of Virginia Charl ottesville, Virginia 22901 firs. Margaret Dietrich Route 2, Box 568 Mr. Edward Kube Gordonsville, Virginia 22042 Board of Supervisors Louisa County Courthouse Ellyn R. Weiss, Esquire P. O. Box 27 Sheldon, Harmon, Roisman and Weiss Louisa, Virginia 23093 1725 I Street, N.W., Suite 506 Washington, D. C.
20006 Mr. J. B. Jackson, Jr.
Cc amonwealth of Virginia Mr. James C. Dunstan Council on the Environment State Corporation Commission 903 Ninth Street Office Building Commonwealth of Virginia Richmond, Virginia 23129 Blandon Building Richmond, Virginia 23209 Mr. Paul W. Purdom Environmental Studies Institute Mr. A. D. Johnson, Chairman Drexel University Board of Supervisors of L]uisa County 32nd and Chestnut Streets Trevillians, Virginia 23170 Philadelphia, Pennsylvania 19104 1134 319
l'r. W. L. Proffitt September 28, 1979 Virginia Electric and Power Company Alan S. Rosenthal, Esquire cc:
Atomic Safety and Licensing Appeal Board U. S. !?uclear Regulatory Commission Washington, D. C.
20555 Michael C. Farrar, Esquire Atomic Safety and Licensing Appeal Board U. S. fluclear Regulatory Commission Washington, D. C.
20555 Dr. John H. Buck Atomic Safety and Licensing Appeal Board U. S. fluclear Regulatory Commission Washington, D. C.
20555 Atomic Safety and Licensing Board Panel V. S. tiuclear Regulatory Commission Washington, D. C.
20555 l134 7,20
NORTH ANNA UNIT NO. 1 DOCKET NO. 50-338 REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE SEPTEliBER 25,1979 EVENT 1.
Perform an engineering analysis of the September 25, 1979 tvent, identifying all of the significant initial conditions, and provide a comparison with events analyzed in Chapter 15 of the North Anna FSAR especially with regard to assuned initial conditions, boundary conditions and system failures.
2.
Identify all plant procedures (number, title, dv.e) used at various phases of the event. Provide a summary describ 'ng the extent to which these procedures were used and why this use wa: considered appro-priate.
3.
Describe, specifically, the criteria that you used to determine that natural circulation was achieved following reactor coolant pump trip.
Identify the instruments relied upon and their readings.
Provide the schedule by which formal written natural circulation cool-down procedures will be available to plant operators.
4.
Provide a description of the reactor coolant pump seal performance during the event.
5.
Provide an analysis of the actual pressurizer level, including the minimum level reached.
6.
Indicate how many times the power operated relief valve on the pressurizer cycled and what indications were available to the operator (e.g., quench tank level, tail pipe temperature, valve position indication,etc.). Explain the apparent second cycling of the PCRV approximately 25 minutes after the first interval (see pressurizer pressure strip chart record).
7.
Quantify the mass loss through the PORV and explain how this was determined.
8.
Considering the nature of how plant parameters (e.g., pressure temperature, pressurizer level, etc.) varied and were displayed to the operator during the event, indicate how and whe, you would have decided to terminate the high pressure i'jection based on the HPI termination criteria reconmended by Westinghouse.
lf 3S; 9.
Indicate incore temperature readings taken during the event.
Provide details as to magnitude, time, and location.
- 10. Describe the extent to which you consulted with Westinghouse during and immediately following this event.
Provide a detailed chronology of significant events during the period 11.
from the initiating event at approximately 0544 hours0.0063 days <br />0.151 hours <br />8.994709e-4 weeks <br />2.06992e-4 months <br /> through return of activitv in the auxiliary building to below MPC limits.
Your ala m typewriter printout indicates tha: for at least one hour 12.
prior 1.0 the turbine trip, the containment <anp level continually cycled to the alarm setpoint. Why?
Identify the number of VEPC0 personnel working in the control rs n during 13.
the first 30 minutes of the event.
14.
State whether the sita emergency plan was activated in any fann.
Describe the extent to which the events which occurred at North Anna 15.
had been sinulated at the Surry Simulator and demonstrated to North Anna operators, prior to September ;
1979.
Discuss the training which North Anna operators have received at the Surry Simulator on tripping RCPs, natural circulation and Bulletin 79-06B HPI requirements.
16.
Explain. in detail the uncontrolled reactor coolant activity release directly to the auxiliary building.
Include why it happened, how it was detected, its release path (s),
a.
how long it continued, the amount, type and form (liquid, gaseous, particulate) of activity released, personnel exposures at the site and potential dose rate at the site boundary and beyond.
b.
Given the inadvertent operator error, equipment failure, or combination thereof, involved on September 25, 1979, state whether an uncontrolled release would have been prevented had the piping to the process vent from the high level waste drain tanks been installed as called for in the plant design rather than in the as-found conditions.
If the answer to b above is in the negative, propose a design c.
modification that will prevent a future uncontrolled release of activity outside containment.
I134 322
. 17.
The FSAR indicates that a high level in the VCT will alarm in the control room and divert the letdown stream to the boron recovery systen. Did any part of this alarm and diversion system activate prior to or during the time that the VCT relief valve was open (assumed to be approximately 10 minutes)? Would such activity af fect the release in 16 above?
1134 323