ML14170A497
| ML14170A497 | |
| Person / Time | |
|---|---|
| Site: | Harris, Brunswick, Robinson  |
| Issue date: | 10/01/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Jackie Jones CAROLINA POWER & LIGHT CO. |
| References | |
| NUDOCS 7910170207 | |
| Download: ML14170A497 (6) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION REGION II 101 MARIETTA ST., N.W., SUITE 3100 ATLANTA, GEORGIA 30303 In Reply Refer To:
RII:JPO 50-325, 50-324 50-400, 50-401 10=A42, 50-403 Carolina Power and Light Company Attn: J. A. Jones Senior Executive Vice President and Chief Operating Officer 411 Fayetteville Street Raleigh, North Carolina 27602 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, Bulletin, or NRR Generic Letter will be issued to recommend or request specific licensee actions. If you have questions regarding the matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely, James O'Reilly Director
Enclosures:
- 1.
IE Information Notice No. 79-25
- 2.
List of IE Information Notice Issued in Last Six Months 7910 170&-9 7
OCT 1 1979 Carolina Power and Light Company
-2 cc w/encl:
A. C. Tollison, Jr.
Plant Manager Box 458 Southport, North Carolina 28461 R. Parsons, Site Manager Post Office Box 101 New Hill, North Carolina 27562 R. B. Starkey, Jr., Plant Manager Post Office Box 790 Hartsville, South Carolina 29550
Accession No.:7908220125 SSINS No.:6870 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 September 28, 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 loss of offsite power and subsequent shedding of non-essential loads.
Unit 3 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 trip logic: tripping Unit 4. This resulted in a loss of offsite power condi tion for Unit 4.
At this time, the Unit 4 startup transformer was out of service due to performance of periodic maintenance. 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 of MCC-D, a turbine runback on Unit 3 was initiated upon loss of rod position indication. This resulted in a reactor trip on high pressurizer pressure. At the time, neither of the two pressurizer spray valves was avail able. One was considered inoperable prior to the transient and the other, temporarily powered by the non-vital portion of MCC-D, had become unavailable earlier as a consequence of the Unit 4 trip.
A subsequent review disclosed inadequacies in the administrative controls over the correction of operational problems exhibited by spray valve PCV-3-455B.
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 understanding between shifts of the operational control of this unusual component configuration.
IE Information Notice No. 79-25 September 28, 1979 Page 2 of 2 Thus, failure to establish guidelines and procedures resulted in unnecessary challenges to the reactor protection system. The subsequent transient resulted in needless thermal stress cycles on the reactor coolant system and its compo nents.
If plant procedures had been followed, or if the Rod Position Indica tion System had been a vital load this transient would have been prevented.
All holders of operating licenses or construction permits should ensure that temporary procedures for plant changes and modifications are established and followed as required.
IE Information Notice No. 79-25 Enclosure October 1, 1979 Page 1 of 2 LISTING OF IE INFORMATION NOTICES ISSUED IN LAST SIX MONTHS Information Subject Date Issued To Notice No.
Issued 79-25 Reactor Trips at Turkey 10/1/79 All power reactor Point Units 3 and 4 facilities holding OLs and CPs 79-24 Overpressurization of 10/1/79 All power reactor Containment of a PWR facilities holding Plant After a Main Steam OLs and CPs Line Break 79-23 Emergency Diesel Generator 9/26/79 All Holders of CPs Lube Oil Coolers and OLs 79-22 Qualification of Control 9/17/79 All Holders of CPs Systems 9/14/79 All Holders of OLs 79-21 Transportation and Commer-9/11/79 All Licensees as Supple cial Burial of Radioactive mental Information to Materials IE Bulletin Nos. 79-19
& 79-20 79-20 NRC Enforcement Policy 9/7/79 All Holders of Reactor (Rev. 1)
NRC Licensed Individuals OLs and CPs and Production Licensees with Licensed Operators 79-20 NRC Enforcement Policy 8/14/79 All Holders of Reactor NRC Licensed Individuals OLs and CPs and Production Licensees with Licensed Operators 79-19 Pipe Cracks in Stagnant 7/18/79 All Holders of Reactor (Correction -
Borated Water Systems at OLs and CPs Enclosure)
PWR Plants 79-19 Pipe Cracks In Stagnant 7/17/79 All Holders of Reactor Borated Water Systems At OLs and CPs PWR Plants 79-18 Skylab Reentry 7/6/79 All Holders of Reactor OLs
r IE Information Notice No. 79-25 Enclosure October 1, 1979 Page 2 of 2 LISTING OF INFORMATION NOTICES ISSUED IN LAST SIX MONTHS Information Subject Date Issued To Notice No.
Issued 79-17 Source Holder Assembly Damage 6/20/79 All Holders of Reactor Damage From Misfit Between OLs and CPs Assembly and Reactor Upper Grid Plate 79-16 Nuclear Incident at Three 6/22/79 All Research Reactors Mile Island and Test Reactors with OLs 79-15 Deficient Procedures 6/7/79 All Holders of Reactor OLs and CPs 79-14 NRC Position of Electrical 6/11/79 All Power Reactor Cable Support Systems Facilities with a CP 79-13 Indication of Low Water 5/29/79 All Holders of Reactor Level in the Oyster Creek OLs and CPs Reactor 79-12 Attempted Damage to New 5/10/79 All Fuel Facilities Fuel Assemblies Research Reactors, and Power Reactors with an OL or CP 79-11 Lower Reactor Vessel Head 5/7/79 All holders of Reactor Insulation Support Problem OLs and CPs