ML19208C800
| ML19208C800 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 08/14/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Herbein J METROPOLITAN EDISON CO. |
| References | |
| NUDOCS 7909270520 | |
| Download: ML19208C800 (3) | |
Text
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August 14, 1979
. s, Docket No. 50-289 Mr. J. G. Herbein Vice President Metronolitan Edison Company P. O. Box 542 Reading, Pennsylvania 19603
Dear Mr. Herbein:
By letter dated August 19, 1977 (GQL 1145) you subnitted a comparison of your current design of the emergency power system at TMI-l with the staff positions.
Upen reviewing your submittal, we find that additional information is required to complete our review. Specific infonnation requests are listed in the enclosure.
You are requested to provide a response to this infonnation within 45 days of receipt of this letter.
Sincerely, h/h Robert W. Reid, Chief Operating Reactors Branch f4 Division of Operating Raactors
Enclosure:
Request for Additional Infonnation-Degraded Grid Voltage cc w/ enclosure: See next page D*h'D M J1
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tietropolitan Edison Company U
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G. F. Trowbridge, Esquire Shaw, Pi ttman, Potts & Trowbridge 1800 ft Street,ff.W.
Washington, D.C.
20036 GPU Service Corporation Richard W. Heward, Project "anager Mr. E. G. Wallace, Licensing Manager 260 Cherry Hill Road 07054 Parsippany, tiew Jersey Pennsylvania Electric Company Mr. R. W. Conrad Vice President, Generation 1001 Broad Street 15907 Johnstown, Pennsylvania 11iss riary V. Southard, Chairman Citizens for a Safe Environment P. G. Box 405 17108 Harrisburg, Pennsylvania Mr. Robert B. Borsum Babcock & Wilcox Nuclear Power Generation Division Suite 420, 7735 Old Georgetown Road Bethesda, Maryland 20014 Government Publications Section State Library of Pennsylvania Box 1601 (Education Building) 17126 Harrisburg, Pennsyltania e
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Enclosure FEQUEST FOR ADDITIONAL INFORMATION THREE MILE ISLAND, UNIT 1
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DEGRADED GRID VOLTAGE In regard to our review of your submittal dated August 19, 1977 concerning b
second level undervoltage protection, several areas need further clarification, Your chosen nominal set point of 3534V and minimum acceptable setpoint (1) of 3423V correlates to 88% and 85.6% of motor rated voltage, respectively.
As both of the voltages are below those recommended by ANSI C84.1-1973 and most manufacturers, show by analysis that a postulated voltage of 89% of 4000V for an indefinite time will not cause thermal damage to the ESF motors.
(2) Provide the time delay of the urdervoltage protection at your chosen setpoint. Provide analysis showing that the time delay for undervoltage protection will preclude any spurious trips from starting large motors and also prevent any thermal damage to the safety related equipment.
Also provide sufficient information (voltage drop analyses) to allow our independent verification that the undervoltage set point and time delay selected wili not cause spurious separation of safety buses from offsite power during all modes of plant operation (start-up, shutdown, power operation and accident condition) due to automatic or manual starting of large motors, bulk or sequential loading or automatic transfer of electrical The analyses should include conditions when the safety buses are loads.
supplied from the Unit Auxiliary Transformer, the Start-up/ Reserve Trans-former or other available offsite connections and assuming the need for electrical power is initiated by an anticipated transient (e.g., unit trip) or an accident, whichever presents the largest load demand. of the staff's letter of June 3,1977 provided model Technical (3)
Any variations should be justified by analysis or Specification (MTS).
The following variations of your proposed Technical Speci-other means.
fications from the MTS should either be included or their omission justified:
The surveillance requirements for the second level undervoltage and loss-of-power relays.
(Refer to Table 4.3.2 of the HTS in Enclosure 2.)
a.
The maximum allowable limits as well as the minimum allowable limits b.
for the setpoint.
The time delay maximum and minimum allowable limits.
c.
In Table 3.3-3 of the MTS, under action statements, it is the staff's position Please that the inoperable channel be placed in the tripped position in one hour.
justify your proposal of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in lieu of this.
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