ML19343B208
| ML19343B208 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 10/24/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Hancock J FLORIDA POWER CORP. |
| References | |
| NUDOCS 8012160026 | |
| Download: ML19343B208 (1) | |
Text
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UNITED STATES
~ 7, NUCLEAR REGULATORY COMMISSION REGION 11 3
101 MARIETTA sT.. N.W. SUITE 3100 o,
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6 ATLANTA. GEORGIA 30303 OCT 2 4195C In Reply Refer To:
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Florida Power Corporation p
ATTN:
J. A. Hancock, Assistant M
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P. O. Box 14042, Mail Stop C-4 J
St. Petersburg, FL 33733 Gentlemen:
This information Notice is provided as an early notification of a possibly significant matter. It is expected that recipients will review the information for possible applicability to their facilities. No specific action or response is requested at this time.
If further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recommend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely, SN -
James P. O'Rei y Director
Enclosures:
1.
IE Information Notice No. 80-37 2.
List of Recently Issued IE Information Notices cc w/ encl:
D. C. Poole, Nuclear Plant Manager 80121eo M g
SSINS No.: 6835 Accession No.:
8008220249 UNITED STATES IN 80-37 NUCLEAR REGULATORY COMMISSION d
0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 October 24, 1980 IE Information Noti'ce No. 80-37: CONTAINMENT COOLER LEAKS AND REACTOR CAVITY FLOODING AT INDIAN POINT UNIT 2 Discription of Circumstances:
This Notice 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 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 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 they are casigned 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 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 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 cavity 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 tae sump pump control floats to prevent their binding, and has repaired the containment sump water level indicators.
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IN 80-37 Octobar 24, 1980 Page 2 of 2 4
The licensee plans in the longer term to replace the containment fan unit cooling coils.
It is anticipated that results of a continuing NRC 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 sp.-cific licensees and applicant actions.
In the interim, we recommend that all licensee ascertain that the potential does not exist for undetected water accumulation in the containment.
This Information Notice is provided to inform licensees of a possibly significat matter. No written response te this Information Notice is required.
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IN 80-37 October 24, 1980 RECENTLY ISSUED IE INFORMATION NOTICES Information Date of Notice No.
Subject Issue Issued to 80-37 Containment Cooler Leaks 10/24/80 All nuclear power reactor and Reactor Cavity Flooding facilities holding an OL at Indian Point Unit 2 or CP 80-36 Failure of steam 10/10/80 All nuclear power generator support 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 80-34 Baron dilution of reactor 9/26/80 All pressurized water coolant during steam reactor facilities generator decontamination holding power reactor OLs 80-33 Determination of teletherapy 9/15/80 All teletherapy timer accuracy (G3) licensees 80-32 Clarification of certain 8/12/80 All NRC and agreement requirements for Exclu-state licensees sive-use shipments of' radioactive saterials 80-31 Maloperation of Gould-8/27/80 All light water reactor Brown Boveri Type 480 facilities holding OLs volt type K-600S and or cps K-DON 600S circuit breakers l
l 80-30 Potential for unaccept-8/19/80 All boiling water reactor able interaction between facilities holding power I
the control rod drive scram reactor OLs or cps.
l function and non-essential I
control air at certain GE BWR facilities 80-29 Broken studs on Terry 8/7/80 All light water reactor turbine steam inlet facilities holding flange power reactor OLs or cps
- Supplement to Notification of 7/29/00 All holders of reactor l
80-06 significant events at and near-term OL l
operating power reactor applicants facilities 80-28 Frompt reporting of 6/13/80 All applicants for and required information holders of nuclear power l
to NRC reactor cps 1
i O Operating Licenses or Construction Permits l
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