ML19340C847
| ML19340C847 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay, Diablo Canyon |
| Issue date: | 10/24/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Crane P PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8012170715 | |
| Download: ML19340C847 (1) | |
Text
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f' jo, UNITED STATES y '
.,.,(f(,g NUCLEAR REGULATORY COMMISSION g
,gj nEGION V 0,
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SulTE 202, WALNUT CREEK PLA?A g
1990 N. CALIFORNIA BOULEVARD
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,,a WALNUT CREEK. CALIFORNIA 94598
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Docket Nos. 50-133, 50-275, 50-323 Pacific Gas and Electric Company 77 Beale Street San Francisco, California 94106 Attention: Mr. Philip A. Crane, Jr.
Assistant General Counsel Gentlemen:
This Information Notice is being forwarded to you for information. No written response to this Information Notice is requireo.
If you have any questions l
related to the suoject, please contact this office.
Sincerely, lI
-MS R. H. Engelken
.j Director Enclosures :
1.
IE Information i:otice ilo. 80-37 2.
List of Recently Issued Information ?!atices cc w/ enclosures:
J. D. Shiffer, FG5E W. Raymond, PG&E E. Weeks, PG3E, Humboldt Bay E. B. Langley, Jr., PG&E I
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SSIriS fio. : 6835 Accession fio.:
8008225249 UllITED STATES Ill 80 37 flVCLEAR REGULATORY COMMISSIO!!
0FFICE OF IllSPECTI0tl AllD.ErlFORCEMEtlT WASHItiGT0t), D.C.
20555 October 24, 1980 I
IE Information ilotice flo. 80-37:
COMTAlf!MErlT COOLER LEAKS AfiD REACTOR CAVITY FLOODIt!G AT If1DIAtt POIflT Ut!IT 2 Discriotion of Circumstances:
This flotice 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 i
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 i
vessel (RPV). This collected water probably caused the detector malfunction, and the water in 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 f om 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 l
(cd and may have been for several days, leaving the operator with no operable j
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 resultinq fron relatively snall cold water leaks; (4) The hold-up tanks which ultimately receive water pumped from the containment sump also receive Unit 1 3
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 onto the containment floor. These coolers have a history of such leakage, which cannot be detected by supply inventory losses since the supply system (service l
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.
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 i
the containment sump water level indicators.
IN 30-37 October 24, 1980 Page 2 of 2 The licensee plans in the lancer torn to renlace the containrent fan unit ccoling coils.
It is anticinated that results of a continuino NRC investication into this incident will result in issuance of an IE Eulletin and/or an NRR Generic Letter in the near future which will reccnnend or recuire specific licensees and acclicant actions.
In the interim, we recommend that all licensee I
ascertain that the potential does not exist for undetected water accumulation in the containment.
This Information Motice is orovided to infern licensees of a possibly significat natter. ?!o written resconse to this Infornation Motice is recu1 red.
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IN C0-37 October 24, 1980
'ECE"TLY ISSUED IE INFr?/ATION NOTICES Infornation
. ate of Notice No.
Subiect Issue Istied to 80-36 Failur? of stean 1C/10/20 All n +1 ear newer "enerator succort bolting reat-facilities holding Ols or cps 80-35 Leaking and dislodged 10/10/80 All categories G and Iodine-124 innlant seeds G1 redical licensees 00-34 "aren dilution of reactor 9/26/S0 All oressurized water ccclant during staan reactor facilities generator cecontanination holding power reactor OLs 80-33 Deternination of teletheracy 9/15/80 All teletherapy tirer accuracy (G3) licensees 80-32 Clarification of certain 8/12/30 All NRC and agr :aent recuirerents for Exclu-state licensees sive-use snipments of radioactive materiais 80-31
'alaceration of Could-3/27/C0 All light water reactor Ercun Joveri Type 4C0 facilities holding OLs volt type K-6CDS and or cps K-50" 600S circuit b rea kers 80-30 Fotential for unaccept-C/19/00 All boiling water reactor able interaction between facilities holding power the control rod drive scran reactor OLs or cps.
fonctirn and non-escential control air at certain GE C'JR facilities 80-29 Broken ctuds en Terry 3/7/30 All light water reactor turnine steam inlet facilities holding flange power reactor OLs or cps
- Supplenent to Notification of 7/29/80 All holders of reactor 80-06 significant events at and near-tern OL operatinq power reactor applicants facilities 80-23 Pronnt reporting of 6/13/80 All applicants for and required information holders of nuclear power to NRC reactor cps
- Operating Licenses or Construction Permits
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