ML19340C843
| ML19340C843 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/24/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Papay L SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| NUDOCS 8012170695 | |
| Download: ML19340C843 (1) | |
Text
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e UNITED STATES y
i NUCLEAR REGULATORY COMMISSION r,
J HEGION V l
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- 1990 N. CALIFORNIA BOULEVARD S
SUITE 202, WALNUT CREEK PLAZA WALNUT CREEK. CALIFORNIA 94596 w
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Docket Nos. 50-206, 50-361, 50-362 i
J Southern California Edison Company P. O. Box 800 2244 Walnut Grove Avenue
.Rosemead, California 91770
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Attention: Dr. L. T. Papay, Vice President Advanced Engineering Gontlemen:
it's Information Notice is being forwarded to you for information. ' No written respuase to this Information flotice is required.
If you have any questions related to the subject, please contact this office.
Sincerely, (f
rn :LL R. H. Engelken Director i
i
Enclosures:
- 1. _ IE Informatici
!!atice No. 30-37 i
2.
List of Recently Issued Information !!otices cc w/ enclosures:
J. M. Curran, SCE j
R. Dietch, SCE i
'8 012170 b f 1
4 SSIris !!o.: 6835 Accession No.:
8008220249 VilITED STATES Ill 80-37
?!UCLEAR REGULATORY COMMISSIO!!
0FFICE OF INSPECTION AND.EilFORCEMEtlT WASHIt!GT0il, D.C.
20555 October 24, 1980 IE Information Notice t!o. 80-37: CONTAlf!4ENT COOLER LEAKS AND REACTOR CAVITY FLOODING AT INDIAN POINT UNIT 2 Discription of Circumstances:
. This iotice contains information regarding multiple service water leaks into containment with resulting damage to reactor instrumentation and potential damaae to the reactor pressure vessel, i
Upon. containment entry on October 17, 1980 at Indian Point Unit 2, to repair a malfunctionina 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 probaoly caused the detector malfunction, and the water in the cavity under the RPV is believed to have been deep enough
% wet several feet of the pressure vessel lower head, causing an unanalyzed
'1ernal 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 nay 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 they are designed to detect pressurized hot water or steam leaks (i.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 i
cannot be detected by supply inventory losses since the supply system (ge, wh onto the containment 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 Peactor Pressure Vessel were ineffective since they pump onto the con-tainment floor for ultimate removal by the (inoperable) containment sump pumps.
There is no water level instrumentation in the cavity under the RPV, nor was i
j 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.
i
i IU 80-37 October 24, 1980 Page 2 of 2 The licensee plans in the longer tern to replace the containment fan unit cooling coils.
It is anticicated that results of a continuing MRC investigation into this incident will result in issuance of an IE Bulletin and/or an NRR Generic Letter in the near future which will recommend or require specific licensees and acclicant actions.
In the interin, we recommend that all licensee ascertain that the potential does not exist for undetected water accumulation in the containne.it.
This Information Notice is provided to inform licensees of a possibly significat matter.
No written response to this Infornation Motice is required.
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IN 80-37 October 24, 1980 RECEilTLY ISSUED IE INFORMATION I0TICES Information Oate of flotice rio.
Subject Issue Issued to 80-36 Failure of stean 10/10/80 All nuclear power generator support boltino.
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 80-34 Boron dilution of reactor 9/26/80 All oressurized water coolant during steam reactor facilities generator decontamination 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 recuirements for Exclu-state licensees sive-use shipments of radioactive materials 80-31 Maioceration of Gould-8/27/80 All light water reactor Brown Goveri Type 480 '
facilities holding OLs valt type K-60CS and or cps K-DOM 600S circuit breakers 80-30 potential for unaccept.
E/19/80 All boiling water reactor able interaction between facilities holding power the control rod drive scram reactor OLs.or~ cps.
i function and non-essential i
control air at certain GE EUR
^
facilities 80-29 Broken studs on Terry 8/7/80 All light water reactor turbine steam inlet facilities holding i
flange power reactor OLs or cps
- 4 Supplement to flotification of 7/29/80' All holders of reactor 80-06 significant events at and near-tern OL.
i operating powt reactor applicants i
facilities 80-28
' prompt reporting of 6/13/80_
All applicants for and reauired information holders of nuclear power to -!lRC reactor cps-
- Operating Licenses or Construction Permits