ML18139A873
| ML18139A873 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna  |
| Issue date: | 11/19/1980 |
| From: | Sylvia B VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-80-310-000 932, NUDOCS 8012040669 | |
| Download: ML18139A873 (4) | |
Text
-7:;
.. ~,
... ?ltcW~ '
PART 21 IIBIT1FICATICXW1, '31>- !>lo-coo
- TN IW1:_
' C-~
DATE OF m*,ll,s\\'6-o DXKIT NO. !i>~Ztst>\\?'61 °1 '>>-~)3!11 DATE DISTRIBUTED. n\\""bl\\i:o f 0 ft\\*
ORIGINl\\L REPQRT~ SUPPlHOOARYD DISTRIBUTION:
. PfACTOR CR) ~.
IE FILES.
-AD/I-41I..c.
-t~
~'RE~
r,~ '.;'-
FEGIONS LIL I IL IVJ V VENOOR BR.
- R-IV LJE3 / WA ~NB 5715 AEOD M\\ffi 7fJJ2.
NRR/DJ:
NRR/DSI
. NRR/DST NPJVOOL ASLBP E!W 450 CEWiRt\\L FILES PDR LPDR TERC\\
.. ACTION:
FUEL CYCLE & D
~'ATERIALS (M)
IE FILES*
ADIFR'SI REGIQ~ IJIIJIIIJIVJV
\\£NOOR BR. R-I_V NVSS / FCMS *. SS-395 LO::B / ff>A
~NB 5715 AEOD M'ffi 7fJJ2.
ASL.BP E/W 450 SAP /SP. n'ffi-7210.Di
-C5\\TRAL FILES 016 CHffRAL FILES ( 01RON)
PDR.
TERA SA9:GUl\\RDS (S) D IE FILES AD/SG AD/ROI REGI~S IJIIJIII;IV;V VENOOR BR. R--IV NPJVOOL fiWSS I SG SS-881 LD-:J3 /.fvPA M'IB 5715
. AEOD M\\ffi 7fJJ2.
ASLBP E/W 450
- COORAL FI l£S 016 C8ITRAL FI LfS ( GtRON)
(BITRAL FILES SS-395 PDR LPDR TERA PRELIMINARY EVALUATION OF THE. ATTACHED REPORT..~l~~,'.~l-~g?PONSIBILITY FOR FOLLOWJP AS SI-OWN BaDW:
It S., *
~ [it..
NRR D it*
1 011 LW' 9c* AdttJti_~ D OTHFR D
-.~***
"'ftet'*
.§6m
- 'i:,t6*
~-
,,, r!tlh1 i;S:'i; 1,..
P.tffi:~;,l;;'
- 1: ~**SI.,,./ \\ -),),-,.,,"
.,,J..;' t~tHJt:f'ff (J: b /{/\\ *}* -~ ~
,ijijl20401PVJ1
~ -
P3/, 8/1'80
- c.,\\,\\go 4
- ~--
~
-~.
i'
0 J
.-.-~.. ~....,
... flD- '3IO-OOO e
V:t:&GINIA ELECTRIC AND PowEB COMPANY R:rcnxoN>>,Vx:aoDLA. 23261 1
November 19, 1980 Mr. James P. O'Reilly, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 3100 Atlanta,
- Georgia 30303
Dear Sir:
\\
Serial No. 932 NO/ESG:ms Docket Nos. 50-280 50-281 50-338 50-339 License Nos. DPR-32 DPR-37 NPF-4 NPF-7 Under the provisions of the. Technical Specifications and 10 CFR 21, NRC Region II was notified on November 14, 1980 that a potential significant deficiency or ~ubstantial safety haz_ard existed at Surry Units 1 and 2 and North Anna Units 1 and 2.
In accordance with the reporting requirements of 10 CFR 21, the following,
- information is submitted:
A.
Name and address of reporting individual:
Hr. B. R. Sylvia, Manager Nuclear Operations and Maintenance Virginia Electric and Powe.r Company P. 0. Box 26666 Richmond, Virginia 23261" 0
B.
Facility, activity and/or component affected:
Surry Units 1 and 2 North Anna Units 1 and 2 C.
Name of firm constructing the facility or supplying the component, activity or service:
Stone & Webster Engineering Corporation Boston, Massachusetts 02107
e VIBOJNa ELECTBJC AND PoWEB COMPANY TO Hr. 'James P~ of.illy 2
D.
Description of defect, deficiency or failure to comply:
Stone* & Webster Engineering Corporation informed Vepco that under certain conditions, an out of phase transfer might occur when the emergency buses are transferred from the offsite power source to the emergency diesel generator after the generators have reached rated speed and voltage because there is no definitive phase relationship between the offsite source and the emergency diesel generator vol-tages and no time permissive for collapsing the residual voltage.
,.On November 14, 1980, Stone Webster Engineering Corporation confirmed a significant out of phase transfer could occur under the following conditions:
- 1. : A Safety Injection signal is received and the diesels start and run on standby.
- 2.
Offsite power is lost, the emergency buses isolate from the offsite supply and are transferred to the diesel generators.
As built, there was no time permissive to allow for collapsing of
- residual bus voltages.
Therefore, an out of phase transfer might have caused severe motor end-turn forces as well as high torsional stresses that could cause motor rotor, coupling or driven equipment.
shaft failures.
- A study of this transfer effect on th~- low head *
- safety injection motors indicates that the resultant volts per Hertz may not be within the recommended allowable limit for a safety transfer per ANSI CS0.41-1977.
E.
Date of determination of reportability:
November 14, 1980 F.
Similar components,.activities or services:
None G.
Corrective Action which has been, is being or will be taken, the
- individual responsible and the length of time to complete the action:
A time delay circuit has been installed on the Surry Unit 2 and North Anna Unit 1 emergency diesel generator output breakers to allow a.2.0 second time delay between the opening of the offsite supply.breakers and closing of the emergency diesel generator breakers.
A 1. 96 second time delay is sufficient for the residual voltages to dissipate to allowabl~ levels.
The modifications will be completed on Surry Unit 1 and North Anna Unit 2 prior to startup from their current out~ges.
e Mr. James P*. of.illy V1aonnA Eu:cra1c AND Pow.zB CoKPANY To H.
Other information:
Any additional information regarding the above topic will be submitted in the Licensee Event Reports.*
Should y~u require further information, please contact this office.
I cc:
Mr. Victor Stello, Director (3)
Office of Inspection and Enforcement Very truly yours,
- f~'J/
.~
v~~_,,~,
B. R?s;1v;;
- Manager - Nuclear Operations and Maintenance
..