05000249/LER-1974-027, Regarding Loss of Core Spray 3A Discharge Pressure
| ML17252A504 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 09/03/1974 |
| From: | Stephenson B Commonwealth Edison Co |
| To: | James Keppler US Atomic Energy Commission (AEC) |
| References | |
| BBS Ltr. #628-74 LER 74-027-00 | |
| Download: ML17252A504 (2) | |
| Event date: | |
|---|---|
| Report date: | |
| 2491974027R00 - NRC Website | |
text
Commonwea&dison One First National~, Chicago, Illinois Addre.ss.~eply to: Post Office Box 767 Chicago, Illinois 60690 Mr; James G. Keppler, Regional Director Directorate of Regulatory Operations-Region U. s. Atomic Energy Connnission 799 Roosevelt Road
- . UNIT 3 "A" CORE. SPRAY HEADER III References: 1) Regulatory Guide 1.16 Rev.l Appendix A 50-249
- 2) Notification of Region III of AEC Regulatory Operations Telephone:*Mr. F. -Maura, 1420 hours0.0164 days <br />0.394 hours <br />0.00235 weeks <br />5.4031e-4 months <br /> on August 28, 1974 Telegram: Mr. J. Keppler, 1420 hours0.0164 days <br />0.394 hours <br />0.00235 weeks <br />5.4031e-4 months <br /> on August 28, 19 ::;J:---:----
- 3) DrawiM Number: M-$58 Report Number: 50-249/1974-27 Report Date: Septembe~ 3, 1974 Occurrence Date: August 28, 1974 Facility: Dresden Nuclear Power* Station, Morris,. Illinois IDENTIFICATION OF OCCURRENCE Ori August 28, 1974 at about 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br />, 3 "A" core spray header pressure was lost.
CONDITIONS PRIOR TO OCCURRENCE Prior to the loss of core spray header pressure, the 3A core spray pump was operated to perform surveillance prior to taking the 2/3 diesel generator out of service.
DESCRIPI'ION OF OCCURRENCE At *about 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> on August 29, 1974 following surveillance of the core spray system, core spray 3A discharge header pressure was lost. The immediate action taken was to check the 3A core spray system valve line up.
It was found during the valve line up check that the 3A core spray pump discharge stop-check valve (3-1402-8.A) did not seat following surveillance.
9303.
I September 3, 1974 Mr. James G. Keppler
.. ' DES!IGNATION OF APPARENT CAUSE (Valves)
The apparent cause of the loss of ~
CQ!'~_§Jl~~y_h~ader __ pr.essur.e-at- ------ -- -----
-- - ------tn.e-~ilne -of-tneoccl.irrenc-ewas-d.ueto-the discharge stop-check valve (3-1402-BA) failing to seat properly.
.ANALYSIS OF OCCURRENCE During the loss of the 3A core spray punip discharge header pressure the safety of the plant and public was not in. jeopardy. The 3B_core spray system and all other emergency core cooling systems were operable at the
.time of the occurrence.
CORRECTIVE ACTION
The immediate corrective actions taken following the discovery was to manually cycle valve 3-1402-BA which seated the stop-check_valve allowing discharge header pressure to return to normal.
Following the return of normal header pressure, the +ine was vented.
In order to remove the 2/3 emergency diesel generator from service, the core spray system surveillance was performed again.
During this surveil-lance, the problem did not reappear. However, the stop-check valve Will be inspected during the next four day outage.
FAILURE DATA In review of past data, no previous failures of this type were found. *In view of the problem and no previous failures, the corrective action taken at this time is considered satisfactory.
BBS:do Sincerely, oxLv cm fUeL IAr---B. B. Stephenson
~ -
Superinterident r**,