ML18136A061
| ML18136A061 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna  |
| Issue date: | 10/01/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Proffitt W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NUDOCS 7910170232 | |
| Download: ML18136A061 (6) | |
Text
' f
. i
\\
c."V,.R REG<,<.
e e
t~:~1
~
~.,.'>
~o~
lf-,t**"'
I_n ~eply Refer To:
RII:JPO 50-338, 50-339 50-404, 50-405 c:5-n:=2ao, 50-~
UNITED STATES NUCLEAR *REGULATORY COMMISSION REGION II 101 MARIETTA ST., N.W., SUITE 3100 ATLANTA, GEORGIA 30303 OCT 1 1979 RE:6iJLATORY D/JrlfrT n, c.
"",.~ COP~
Virginia Electric and Power Company Attn:
W. L. Proffitt Senior Vice President, Power P. O. Box 26666 Richmond, Virginia 23261 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 t~e Director of the appropriate NRC Regional Office.
Enclosures:
- 1.
IE Information Notice No. 79-25
. 2.
List of IE Information Notice Issued in Last Six Mqnths Sincerely,
~-~~..,, r-c_........ _
James P. Q ~eilly Director*'..-
"rift o l 'lOz:..3 ~
~
Virginia Electric and Power Company cc w/encl:
W.R. Cartwright, Station Manager Post Office Box 402 Mineral, Virginia 23117 P. G. Perry Senior Resident Engineer Post Office Box 38 Mineral, Virginia 23117 W. L. Stewart, Manager Post Office Box 315 Surry, Virginia 23883
- ;.:'"-:.~
OCT 1 1979 ~.,._--=-----,----*--. -~----*--*-..
- ------*-.--,0:.-~... ---- ---~------
Accession No.:7908220125 SSINS No. : 6870 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 September 28, 1979 IE Inform~tion 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) ttD" 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-3-45SB.
The original Hagan controller for spray valve PCV-3-4SSB 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 ~anual controller was not performed under established guidelines.
Addit::i..onally, no temporary procedure had been issued to ensure consistent understanding between shifts of the operational control of this unusual component configuration.
J
-***-----~~-, **~-----------~-
-~
- *~r-* '* -.,.
~--.-*
e IE Information Notice No. 79-25 e
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 October 1, 1979 Information Notice No. 79-25 79-24 79-23 79-22 79-21 79-20 (Rev. 1) 79-20 79-19 (Correction -
Enclosure) 79-19 79-18 LISTING.OF IE INFORMATION NOTICES ISSUED IN LAST SIX MONTHS Subject Reactor Trips at Turkey Point Units 3 and 4 Overpressurization of Containment of a PWR Plant After a Main Steam Line Break Emergency Diesel Generator Lube Oil Coolers Qualification of Control Systems Transportation and Commer-cial Burial of Radioactive Materials NRC Enforcement Policy NRC Licensed Individuals NRC Enforcement Policy NRC Licensed Individuals Pipe Cracks in Stagnant Borated Water Systems at PWR Plants Pipe Cracks In Stagnant Borated Water Systems At PWR Plants Skylab Reentry Date Issued 10/1/79 10/1/79 9/26/79 9/17 /79 9/14/79 9/11/79 9/7/79 8/14/79 7 /18/79 7/17/79 7/6/79 Enclosure Page 1 of 2 Issued To All power reactor facilities holding OLs *and CPs All power reactor facilities holding OLs and CPs All Holders of CPs and OLs All Holders of CPs All Holders of OLs All Licensees as Supple-mental Information to IE Bulletin Nos._79-19
& 79-20 All Holders of Reactor OLs and CPs and Production Licensees with Licensed Operators All Holders of Reactor OLs and CPs and Production Licensees with Licensed Operators All Holders of Reactor OLs and CPs All Holders of Reactor OLs and CPs All Holders of Reactor OLs
IE Information Notice No. 79-25 October 1, 1979 Information Notice No. 79-17 79~16 79-15 79-14 79-13 79-12 79-11 LISTING OF INFORMATION NOTICES ISSUED IN LAST SIX MONTHS Subject Date Issued Source Holder Assembly Damage 6/20/79 Damage From Misfit Between Assembly and Reactor Upper Grid Plate Nuclear Incident at Three 6/22/79 Mile Island Deficient Procedures 6/7/79 NRC Position of Electrical 6/11/79 Cable Support Systems Indication of Low Water 5/29/79 Level in the Oyster Creek Reactor Attempted Damage to New 5/10/79 Fuel Assemblies Lower Reactor Vessel Head 5/7/79 Insulation Support Problem Enclosure Page 2 of 2 Issued To All Holders of Reactor OLs and CPs All Research Reactors and Test Reactors with OLs All Holders of Reactor OLs and CPs All Power Reactor Facilities. with a CP All Holders of Reactor OLs and CPs All Fuel Facilities Research Reactors, and Power Reactors with an OL or CP All holders of Reactor OLs and CPs
- -*-n-
- --. -*----* -*-*--*...-*-.--~.~ *- *-* -
~~ *~ **
.**r*--.,.._.,. __ **~*,** ----*------********-*-**-** ***----*--*-**