ML19253A179
| ML19253A179 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 08/03/1979 |
| From: | Parr O Office of Nuclear Reactor Regulation |
| To: | Proffitt W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NUDOCS 7908200025 | |
| Download: ML19253A179 (4) | |
Text
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h UNITED STATES g
NUCLEAR REGULATORY COMMISSION y
WASHINGTON, D. C. 20555 9
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AUG 3 1979 Docket No:
50-339 Mr. W. L. Proffitt Senior Vice President - Power Virginia Electric & Power Company P. O. Box 26666 Richmond, Virginia 23261
Dear Mr. Proffitt:
SUBJECT:
STAFF POSITION ON ELECTRICAL PROTECTION OF CONTAINMENT PENETRATIONS FOR NORTH ANNA POWER STATION, UNIT 2 General Design Criterion 50, " Containment Design Basis", requires, in srt that the reactor containment structure, including penetrations, be designed so that the containment structure can, without exceeding the design leakage rate, accommodate the conditions resulting from any loss-of-coolant accident.
Conformance to the requirements of IEEE Standard 317 as augmented by Regulatory Guide 1.63 provides an acceptable method for complying with the requirements of GDC 50.
The regulatory position in Regulatory Guide 1.63 states that the electrical penetration assembly should be designed to with-stand, without loss of mechanical integrity, the maximum short-circuit vs.
time conditi,'s that could occur given single random failures of circuit overload ree'.cction devices.
The circuit overload protection system should conform to the criteria of IEEE Standard 279-1971.
Our review of your application showed that for an operating license for North Anna Power Station, Unit 2, your design for protection of the contain-meat electrical penetrations against overcurrent conditions did not meet the requirements of the single failure criterion of IEEE Standard 279-1971.
Therefore, unless it can be demonstrated that the penetration associated with each load is designed to sustain the fault current indefinitely with-out impairing its integrity, we require that the design of the overcurrent protective system provide for independent primary and backup protective devices to interrupt the fault current to each load within the specified time. We also require that if a modification to the design is required, that hardware implementation be completed prior to startup after the first refueling oatage.
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303 339 w
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4 Mr. W. L. Proffitt For penetrations associated with miscellaneous non-Class lE loads which do not have independent backup protective devices and which do not need to be energized when containment integrity must be maintained, we have accepted the removal of power from the circuits by opening the supply circuit breaker as a satisfactory way of preventing fault currents from impairing the integrity of the penetration.
If this option is used, we require that the admin'strative controls and procedures used to assure that the power feeds remain disconnected, when containment integrity must be maintained, shall be governed by technical specification requirements and surveillance schedules.
Those non-Class lE circuits that either cannot or do not have power removed during reactor operation are required to have independent primary and backup protective devices to interrupt the fault current within the specified time or the associated penetration shall be shown capable of carrying the fault current indefinitely without impairing its integrity.
The use of non-Class lE protective devices to provide the primary end backup overcurrent protection for penetration assemblies carrying non-Class lE circuits is acceptable if it can be demonstrated that a seismic event would not result in a fault on non-Class lE circuits inside containment.
The circuit breakers in non Class 1E circuits must be of high industrial quality, verifiable by appropriate procurement documentation, with a seismic capability that assures, as a minimum, that these breakers remain operable during an operating basis earthquake.
Further, we require these devices be included in the Technical Specification periodic surveillance program.
Accordingly, we request that you amend your FSAR to clearly state your intent regarding compliance with our position as sta;ed above.
Please inform us within seven days of receipt of this letter of your schedule for providing the informatio1 described above.
Sincerely, D P r'r ef, Branch No. 3 Light Water Reactors Division of Project.d:nagement ec: See next page p((a UiUulhSL 0 nnmq 803 340
.P Mr. W. L. Proffitt cc: Mr. Anthony Gambaradella Cl arence T. Kipps, Jr.. Es q.
Office of the Attorney General 1700 Pennsylvania Aver.ce, N. W.
11 South 12th Street - Room 308 Washington, D. C.
20006 P.ichmond, Virginia 23219 Carroll J. Sa vage, Esq.
Richard M. Foster, Esq.
1700 Pennsyl vania Avenue, N.W.
211 Stribling Avenue Wa shington, D. C.
20006 Charlottesville, Virginia 22903 Mr. James C. Dunstan Michael W. Maupin, Esq.
State Corporation Commission Hunton, Williams, Gay & Gibson Conmonvealth of Virginia P. O. Box 1535 Blandon Building Richmond, Virginia 23212 Richmond, Virginia 23209 Mrs. June Allen Alan S. Rosenthal, Esq.
412 Owens Drive Atomic Safety and Licensing Appeal Board ibnt sville, Alabama 35801 U.S. Nuclear Regulatory Conmission Washington, D. C.
20555 Mr. James Torson 501 Leroy Michael C. Farrar, Esq.
Socorro, New Mexico 87801 Atemic Safety and Licensing Appeal Board U.S. Nuclear Regulatory Commission Mrs. Margaret Dietrich Washington, D. C.
20555 Route 2, Box 568 Gordonsville, Virginia 22942 Dr. John H. Buck Atomic Safety and Licensing Appeal Board Willi aa H. Rodgers, cr., Esq.
U.S. Nuclear Regulatory Com:iission Georgetowi University Law Center Washington, D. C.
20555 600 New Jersey Avenue, N'.W.
Washington,D. C 20001 Atomic Safety and Licensing Board Panel U.S. Nuclear Regulatory Comaission Fr. Peter S. Hepp Washington, D. C.
20555 Executive Vice President Sun Shipping & Dry Dock Company Mr. Michael S. Ki dd P. O. Box 540 U.S. Nuclear Regulatory Comaission Chester, Pennsylvania 19013 P. O. Box 128 Spotsivania, Virginia 22553 Mr. R. B. Briggs Associate Director Dr. Paul W. Purdom 110 Evans Lane Department of Civil Engineering Oak Ridge, Tennessee 37830 Drexel University Philadel phia, Pennsyl vania 19104
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Mr. W. L. Proffitt cc:
Dr. Lawrence R. Quarles
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Apartment No. 51 Kenda l-a t-Long wood Kennett Square, Pennsyl vania 19348 Fr. Irwin B. Mroot Citizens Energy Forum P. O. Box 138 Mc Lean, Vi rginia 22101 James B. Dougherty, Esq.
Potomac Alliance P. O. Box 9306 Nashington D. C.
20005 i
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803 342
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