ML19254C725
| ML19254C725 | |
| Person / Time | |
|---|---|
| Issue date: | 10/02/1979 |
| From: | Pappas H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Wright G ILLINOIS, STATE OF |
| References | |
| NUDOCS 7910170266 | |
| Download: ML19254C725 (1) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION
- E REGION 111 8
799 ROOSEVELT ROAD 0,
GLEN ELLYN. ILLINOIS 60137
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OCT 2 1979 State of Illinois Department of Public Health ATTN: Mr. Gary N. Wright, Chief Division of M clear Safety 535 West Jefferson Street Springfield, IL 62761 Gentlemen:
The enclosed IE Information Notice No. 79-25 titled " Reactor Trips at Turkey Point Units 2 and 3" was sent to the following licensees on Oct G r 1, 1979, for information:
American Electric Power Dervice Corporation Indiana and Michigan Power Company D. C. Cook 1, 2 (50-315, 50-316)
Cincinnati Gas & Electric Company Zimmer (50-358)
Cleveland Electric Illuminating Company Perry 1, 2 (50-440, 50-441)
Commonwealth Edison Company Braidwood 1, 2 (50-456, 50-457)
Byron 1, 2 (50-454, 50-455)
Dresden 1, 2, 3 (50-10, 50-237, 50-249)
La Salle 1, 2 (50-373, 50-374)
Quad-Cities 1, 2 (50-254, 50-265)
Zion 1, 2 (50-295, 50-304)
Cons,umers Power Company Big Rock Point (50-155)
Midland 1, 2 (50-329, 50-330)
Palisades (50-255)
Dairyland Power Cooperative LACBWR (50-409)
Detroit Edison Company Fermi 2 (50-341)
Illinois Power Company Clinton 1, 2 (50-461, 50-462)
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State of Illinois OCT 2 1979 Iowa Electric Light & Power Company Duane Arnold (50-331)
Northern Indiana Public Service Company Bailly (50-367)
Northern States Power Company Monticello (50-263)
Prairie Island 1, 2 (50-282, 50-306)
The Ohio Edison Company Erie 1, 2 (50-580, 50-581)
Public Service of Indiana Marble Fill 1, 2 (50-546, 50-547)
Toledo Edison Company Davis-Besse 1 (50-346)
Union Electric Company Callaway 1, 2 (50-483, 50-486)
Wisconsin Electric Power hmpany Point Beach 1, 2 (50-2t,6, 50-301)
Wisconsin Public Service Corporation Kewaunee (50-305)
Sincerely, ff Helen Pappas, Chief Administrative Branch
Enclosure:
IE Information Notice No. 79-25 cc w/ encl:
Mr. D. W. Kane, Sargent & Lundy Central Files Reproduction Unit NRC 20b Local PDR NSIC TIC 1157 135
Accession No.: 7908220125 SSINS No.:
6870 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 October 1, 1979 IE Information Notice 79-25 REACTOR TRIPS AT TURKEY POINT UNITS 3 AND 4
Background
On August 3, Turkey Point Units 3 and 4 tripped while operating at full power.
A voltage spike on a second protection channel caused Unit 4 to trip during surveillance testing on the reactor protection system.
This resulted in a Unit 3 loss of offsite power and subsequent shedding of non-essential loads.
tripped as the result of high coolant pressure caused by a turbine runback.
Discussion While performing a periodic test on channel "C" of the T-Average and Delta T Protection Channels, a spurious signal on channel "A" completed a 2 out of 3 tripping Unit 4.
This resulted in a loss of offsite power condi-trip logic:
tion for Unit 4.
At this time, the Unit 4 startup transfomer was out of service due to performance ::f periodic maintancace.
This condition caused the initiation of the emergency diesel generator load sequencer which resulted in the shedding of non-vital loads.
Among the non-vital loads shed, were those on Motor Control Center (MCC) "D" which is common to both units.
Since the Rod Position Indication System for both units is powered by the non-vital portion t,f MCC-D, a turbine runback on Unit 3 was initiated upon loss of rod This resulted in a reactor trip on high pressurizer position indication.At the time, neither of the two pressurizer spray valves was avail-pressure.One was considered inoperable prior to the transient and the other, able.
temporarily powered by the non-vital portion of MCCD, had become unavailable earlier as a consequence of the Unit 4 trip.
A subsequent review disclosed inadeqacies in the administrative controls over the correction of operational problems exhibited by spray valve PT'-3-4558.
The original Hagan controller for spray valve PCV-3-455B had been disconnected and was replaced by another manual controller which was plugged into the valve control circuit and which had been taped to the top of a console in the main control room. The actual installation of the manual controller was not performed under established guidelines.
Additionally, no temporary procedure had been issued to ensure consistent understar. ding between shifts of the operational control of this enusual comnonent confiauration.
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