ML20032C296
| ML20032C296 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 10/30/1981 |
| From: | Murray T TOLEDO EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| K81-38, RO-NP-09-81-02, RO-NP-9-81-2, NUDOCS 8111090621 | |
| Download: ML20032C296 (3) | |
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3 TOLEDO EDISON October 30, 1981 Log No. K81-38 FILE: RR 2 (NP-09-81-02)
Docket No. 50-346 License No. NPF-3 p)v Mr. James G. Keppler S~
a-f Regional Director, Region III j
g j '.
Office of Inspection and Enforcement NOVO 61981> %
~
U. S. Nuclear Regulatory Commission 4
799 Roosevelt Road T,
u..,muutoneon Glen Ellyn, Illinois 60137 II -
Dear Mr. Keppler:
/.&l[Ts Enclosed are two copies of Reportable Occurrence NP-09-81-02, wh c are being submitted to you in accordance with Technical Specification 6.9 to provide 30 day written notification of this occurrence.
Yours truly,
/ m Doh G Terry D. Murray Station Superintendent Davis-Besse Nuclear Power Station TDM/ljk Enclosure c:
Mr. Norman Haller, Director Office of }bnagement and Program Analysis Encl:
2 copies Ohio Environmental Protection Agency Northwest District Office Encl:
1 copy Mr. Luis Reyes NRC Resident Inspector Encl:
1 copy Ofbb PDR THE TOLEDO EDISON COMPAN:
.OlSON PLAZA 300 MADISON AVENUE TOLEDO. OHIO 43G52 4 bbi y
E TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE rep 0RTABLE OCCUR.lENCE NP-09-81-02 DATE OF EVENT: October 1, 1981 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE: Collection box discharge temperature to lake ex-cceded intake temperature by greater than the allowed 20 F.
Conditions Prior to Occurrence: The unit was in Mode 1 with Power (MNT) = 2686 and Load (Gross MWE) = 885.
Description of Occurrence: On October 1, 1981 at 0952 h'ours while performing Surveillance Test ST 5099.02, Miscellaneous Instrument Daily Checks, the Shift Supervisor was informed that. collection box discharge temperature exceeded lake temperature by greater than 20 F.
At 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> on September 30, 1981, Cooling Tower Makeup Pump 1-2 and the Dilution Pump were removed from service for pre-ventative maintenance to remove silt from the intake structure bay in which these pumps are located. The computer alarm " Collection Box Out Flow to Lake" was then in alarm. At 1857 hours0.0215 days <br />0.516 hours <br />0.00307 weeks <br />7.065885e-4 months <br /> on September 30, 1981, a computer alarm (T191) was received which read " Collection Box Outlet Temperature Rise to Lake".
This alarm actuates at a differential temperature of 19 F.
The temperature differca-tial of greater than 20 F occurtad during the period of 2100 hours0.0243 days <br />0.583 hours <br />0.00347 weeks <br />7.9905e-4 months <br /> on September 0
30, 1981 through 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br /> ot. October 1, 1981. The average differential temp-erature was 21.710F for this time period. Environmental Technical Specification 2.1.1, Maximum Discharge Temperature Difference Above Ambient Lake Temperature, was exceeded. The operator then diverted flow from the operating cooling tower makeup pump to the collection box, and the differential temperature returned within limits.
Designation of Apparent Cause of Occurrence: The primary cause for this occurrence is attributed to personnel error. Appropriate and timely action was not taken when the alarms were received.
In addition, the alarm wording did not adequately define the high 6titerential temperature condition. The lake temperature differential alarm was indicated by 1857 hours0.0215 days <br />0.516 hours <br />0.00307 weeks <br />7.065885e-4 months <br /> on September 30, 1981, by alarm point T191 which reads " Collection Box Outlet Temperature Rise to Lake".
The description for T191 alarm point was not substantial in providing proper w tning. Between 1846 and 1857 hours0.0215 days <br />0.516 hours <br />0.00307 weeks <br />7.065885e-4 months <br />, seven alarms of similar wording occurred on the alarm printer. This was flow alarm point F201 which reads " Collection Box Outlet Flow to Lake".
Alarm point T191 was misinterpreted due to similar wording for the F201 alarm point which was also alarming. Alarm point T191 alarms at a differential
. temperature of 19 F, Alarm point T189 which reads " Collection Box Out Temp Rise 0
to Lake" alarms at n' temperature differential of 150F was not on monitor.
Since alarm point T191 will only print for change from normal to high, or high to normal, further warning of this differential was not identified until Surveillance Test ST 5099.02 was evaluated.
3 TOLEDO EDISO: CO:4PA ;Y DAVIS-BCSSE :;UCLEAR POWER STATIO:; C;IT 0::t REPORTABLE OCCURRE:;CE ;P-09-81-02 PAGE 2 Analysis of Occurrence: There was no danger to the health and safety of the public or to station personnel.
It is believed that the slight increr.se in temperature did not cause any significant environmental damage. A license amendment has been previously submitted to the !;RC to delete this Environmental Technical Specifica-i tion as a result of the Yellow Creek court decision.
Corrective Action: A memorandum from the Operations Engineer was issued to appro-priate operations personnel to caution them on this occurrence. The computer alarm T191 description was changed from " Collection Box outlet Temperature Rise to Lake" to " Lake Delta Temperature High" and computer alarm T189 was changed from
" Collection Box Out Temp Rise to Lake" to " Lake Delta Temperature Rising". Alarm point T189 was placed on monitor.
Failure Date-Similar occurrences occurred in NP-09-81-01 due to procedural deficienci.s.
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