ML19340C846
| ML19340C846 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 10/24/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Withers B PORTLAND GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 8012170708 | |
| Download: ML19340C846 (1) | |
Text
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T/L f Kt20 9[o, UNITED STATES 8\\
e g*f,g NUCLEAR REGULATORY COMMISSION
- f, -[E s
REGION V g.
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1990 N. CALIFORNIA BOULEVARD e"
SUITE 202, WALNUT CREEK PLAM 4,,.
WALNUT CR EEK, CALIFORNIA 94596
- i T 1330 Docket No. 50-344 i
Portland General Electric Company 121 S. W. Salmon Street Portland, Oregon 97204 Attention: Mr. Bart D. Withers Vice President Nuclear Gentlemen:
This' Information Notice is being forwarded to you for information.
No written response to this Information Notice is required.
If you have any questions related to the subject, please contact this office.
Sincerely,
[G a m t [.- -
6M i e
R. H. Engelken Director
Enclosures:
1.
IE Information Notice No. 80-37 2.
List of Recently Issued Information Notices cc'a/ enclosures:
C. P. Yundt, PGE J. W. Durham, Esq., PGE L
k v
0 12170
- 7cy
SSItlS No.: 6835 Accession flo. :
8008220249 UNITED STATES IN 80-37 NUCLEAR REGULATORY COMMISSION 0FFICE OF If!SPECTION AND.ENFORCEMErlT MASHINGTON, D.C.
20555 October 24, 1980 IE Information ?!otice t!o. 80-37:
CONTAITNENT COOLER LEAKS AND REACTOR CAVITY FLOODIt!G AT INDIAN POINT UNIT 2 Discrintion of Circumstances:
This !!otice contains information regarding multiple service water leaks into containment with resulting damage to reactor instrumentation and potential damage to the reactor pressure vessel.
Upon. containment entry on October 17, 1980 at Indian Point Unit 2, to repair a malfunctioning power range nuclear detector, it was discovered that a significant amount of water was collected (approximately 100,000 gal) on the containment floor, in the containment sumps, and in the cavity under the reactor pressure vessel (RPV). This collected water probably caused the detector malfunction, and the water ir, the cavity under the RPV is believed to have been deep enough to wet several feet of the pressure vessel -lower head, causing an unanalyzed thermal stress condition of potential safety significance.
This condition resulted from the following combination of conditions:
(1) Both containment sump pumps were inoperable, one due to blown fuses from an-unknown cause and the other due to binding of its controlling float; (2) The two containment sump level indicating lights which would indicate increasing water level over the water level range present in the containment were stuck (on) and may have been for several days, leaving the operator with no operable instrumentation to measure water level in the containment;-(3) The moisture level indicators in the containment did not indicate high moisture levels, apparently because thcy are designed to detect pressurized hot water or steam leaks (
.e., a LOCA), and are not sensitive to the lower airborne moisture levels resulting from relatively small cold water leaks; (4) The hold-up tanks which ultimately receive water pumped from the containment sump also receive Unit 1 process water, lab drain water, etc. These other water sources masked the effect of cessation of water flows from the Unit 2 sump; (5) There were significant, multiple service water leaks from the containment fan cooling units directly-cannot be detected by supply inventory losses since the supply system (ge, wh onto the containnent floor. These coolers have a history of such leaka service water system) is not a closed system; (6) The two' submersible pumps in the cavity-under the Reactor Pressure Vessel were ineffective since they pump onto the con-tainment floor for ultimate removal by_ the (inoperable) containment sump pumps.
I-There is no water level instrumentation in the qavity under the RPV, nor was
-there any indication outside the containment when these pumps are running.
.The licensee has installed redundant sump level annunciated alarms in the control room and has installed an annunciated alarm in the control room to indicate _ if either submersible pump in the reactor cavity. activates. The licensee has also repaired the service water leaks,~ installed guide bushings' on the sump pump control floats to' prevent their ' binding, and has repaired
-the containment sump water level indicators.
O IN 80-37 October 24, 1980 Page 2 of 2 The licensee olans in the lonner tern to replace the containment fan unit cooling coils.
It is anticicated that results of a continuino NRC investication into this incident will result in issuance of an IE Bulletin and/or an NRR Generic Letter in the near future which will recemrend or recuire specific licensees and aoplicant actions.
In the interin, we recommend that all licensee ascertain that the potential does not exist for undetected water accumulation in the containment.
This Infornation Notice is orovided to inform licensees of a possibly significat natter.
i!o written resconse.o this Information Notice is reauired.
IN 00-37 October 24, 1980 RECENTLY ISSUED IE INFOPPATION MOTICES Information Eate of Notice No.
Sub.iec t Issue Issued to 80-36 r ilure of stean 10/10/30 All nuclear cower a
generator succort bolting reactor facilities holding OLs or cps 80-35 Leaking and dislodged 10/10/80 All categories G and Iodine-124 implant seeds G1 medical licensees 00-34 Corca dilution of reactor 9/26/S0 All oressurized water coolant during steam reactor facilities generator decontanination holding power reactor OLs 80-33 Deternination of teletherapy 9/15/80 All teletherapy timer accuracy (G3) licensees 80-32 Clarification of certain 8/12/80 All MRC and agreement requirements for Exclu-state licensees sive-use shipments of radioactive materiais 80-31 "alooeration of Could-8/27/00 All light water reactor Crown Boveri Type 400 facilities holding OLs volt tyne K-600S and or cps K-DON 6005 circuit breakers 80-30 Potential for unaccept-8/19/80 All boiling water reactor able interaction between facilities holding power the control rod drive scran reactor OLs or cps.
function and non-essential centrol air at certain GE CWR facilities 80-29
'roken studs on Terry 8/7/30 All light water reactor turbine steam inlet facilities holding flange power reactor OLs or cps
- Supplement to Notification of 7/29/80 All holders of reactor 80-06 significant events at and near-tern OL operating power reactor applicants facilities 80-23 Fremot reporting of 6/13/80 All applicants for and required information holders of nuclear power to MRC reactor cps
- Operating Licenses or Construction Permits