ML20028E044
| ML20028E044 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 01/11/1983 |
| From: | Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| Shared Package | |
| ML20028E038 | List: |
| References | |
| LER-82-085-03L-02, LER-82-85-3L-2, NUDOCS 8301200293 | |
| Download: ML20028E044 (3) | |
Text
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, U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT CONTROL BLOCK / / / / / / / (1) (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)
/0/1/ /V/A/N/A/S/2/ (2) /0/0/-/0/0/0/0/0/-/0/0/ (3) /4/1/1/1/1/ (4) / / / (5)
LICENSEE CODE LICENSE NUMBER LICENSE TYPE CAT UR /L/ (6) /0/5/0/0/0/3/3/9/ (7) /1/2/1/5/8/2/ (8) / 0/1/1/1/ 8/ 3/ (9)
DOCKET NUMBER EVENT DATE REPORT DATE EVENT DESCRIPTION AND PROBABLE CONSEQUENCES (10)
/0/2/ / On December 15, 1982, with Unit 2 at full power, Emergency Diesel Generator (EDG)/
/0/3/ / "2J" was removed from service for 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> to adjust voltage regulator response /
/0/4/ / time. This event is reportable pursuant to T.S. 6.9.1.9.b. The requirements of /
/0/5/ / the Action Statement of T.S. 3.8.1.1 were met. The public health and safety were/
/0/6/ / not affected. While reviewing EDG test results on January 5, 1983, the Station /
/0/7/ / Nuclear Safety and Operating Committee determined that EDG test results were not /
/0/8/ / being correctly evaluated. This event is reportable pursuant to T.S. 6.9.1.9.c. /
SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE
/0/9/ /E/E/ (11) /X/ (12) /Z/ (13) /I/N/S/T/R/U/ (14) /C/ (15) /Z/ (16)
SEQUENTIAL OCCURRENCE REPORT REVISION LER/R0 EVENT YEAR REPORT NO. CODE TYPE NO.
(17) REPORT NUMBER /8/2/ /-/ /0/8/5/ /Ns / /0/3/ /L/ /-/ /0/
ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRD-4 PRIME COMP. COMPONENT TAKEN ACTION ON PLANT METHOD HOURS SUBMITTED FORM SUB. SUPPLIER MANUFACTURER
/E/ (18) /Z/ (19) /Z/ (20) /Z/ (21) /0/0/0/0/ (22) /Y/ (23) /N/ (24) /A/ (25) /B/0/9/3/
(26)
CAUSE DESCRIPTION AND CORRECTIVE ACTIONS (27)
/1/0/ / Voltage regulator drift caused a less than optimal voltage regulator response. /
/1/1/ / "2J" EDG was removed from service to adjust the voltage regulator. "2J" EDG was /
/1/2/ / returned to service 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> af ter being removed from service. A review of past /
/1/3/ / "2H" and "2J" EDG results showed that the most recent test results met T.S. sur- /
/1/4/ / veillance criteria. Procedures will be revised to clarify acceptance criteria. /
, FACILITY METHOD OF
! STATUS % POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION (32)
/1/5/ /E/ (28) /1/0/0/ (29) / NA / /A/ (31) / Operator Observation /
ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY (35) LOCATION OF RELEASE (36)
/1/6/ /Z/ (33) /Z/ (34) / NA / / NA /
PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION (39)
/1/7/ /0/0/0/ (37) /Z/ (38) / NA /
PERSONNEL INJURIES NUMBER DESCRIPTION (41)
/1/8/ /0/0/0/ (40) / NA /
LOSS OF OR TYPE DAMAGE TO FACILITY ( }
DESCRIPTION
/l/9/ /Z/ (42) / NA /
PUBLICITY ISSUED DESCRIPTION (45) NRC USE ONLY
- /2/0/ /N/ (44) / NA /////////////
W. R. CARTWRIGHT PHONE (703) 894-5151 8301200293 03611 i DR ADOCK 050003
f Virginia Electric and Power Company North Anna Power Station, Unit No. 2
Attachment:
Page 1 of 2 Docket No. 50-339 Report No. LER 82-085/03L-0 Description of Event An engineering review of a December 13, 1982 Unit 2 "2J" Emergency Diesel Generator (EDG) surveillance test indicated that the Unit 2 "2J" EDG voltage regulator response time could be improved. On December 15, 1982, with Unit 2 at full power, EDG "2J" was removed from service for 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> to adjust voltage regulator response time. This event is report-able pursuant to T.S. 6.9.1.9.b.
On January 5, 1982 the Station Nuclear Safety and Operating Committee (SNSOC) determined that EDG test results were not being correctly evaluated. T.S. surveillance requirement 4.8.1.1.2 item a.4 requires the generator voltage and frequency to be 4160 420 volts and 60 1.2 Hz within 10 seconds af ter a start signal. This requirement had previously been interpreted as requiring the voltage and frequency to pass through the required bands within 10 seconds but not necessarily stabilizing within the bands within 10 seconds. The Station Nuclear Safety and Operating Committee determined that T.S. required the voltage and frequency to be stabilized within 4160 t 420 volts and 60 1.2 Hz within 10 seconds. This event is reportable pursuant to T.S. 6.9.1.9.c.
Probable Consequences of Occurrence Both the "2J" and "2H" Emergency Busses continued to be powered from their normal offsite sources during the event. The "2H" EDG was operable during the event. Increased surveillance of the offsite power sources and increased "2H" EDG surveillance operability testing were performed pursuant to the Action Statement of T.S. 3.8.1.1. The "2J" EDG was returned to service within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> as required by the Action Statement of T.S. 3.8.1.1.
A review of past "2H" and "2J" EDG performance showed that the most recent test results met T.S. surveillance criteria. Although several tests reviewed did not meet the T.S. surveillance criteria, neither EDG i has ever failed to carry its emergency bus due to regulator voltage calibration problems (one complete failure of voltage regulation has
, occurred but calib ratio ~ problems were not involved). Eighteen month j blackout tests previously performed met all acceptance criteria. The out-of-spec voltage regulation has not prevented the EDG from performing their design function. The public health and safety were not affected.
Cause of Event
{
l Voltage regulator drift caused a less than optimal voltage regula-tor time response. "2J" EDG was removed from service to adjust the i voltage regulator.
r
Attachment:
Page 2 of 2 Incorrect evaluation of the EDG test results in the past was caused by an incorrect interpretation of T.S. surveillance requirements.
Immediate Corrective Action Increased surveillance of the offsite power sources and increased "211" EDG surveillance operability testing were performed pursuant to the Action Statement of T.S. 3.8.1.1. EDG "2J" was returned to service 7' hours af ter being removed from service. Operability testing performed prior to returning the 2J" EDG to service showed significant' improve-ment of voltage regulator time response.
A review of recent "2H" and "2J" EDG test results was made to ensure that the most recent EDG test results meet T.S. surveillance requirements.
Scheduled Corrective Action '
Procedures will be revised to clarify voltage and frequency accep-tance criteria.
Actions Taken to Prevent Recurrence No actions to prevent recurrence, other than those already de-scribed are required.
Generic Implications This event does not have generic. implications.
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