ML19274E423
| ML19274E423 | |
| Person / Time | |
|---|---|
| Issue date: | 03/06/1979 |
| From: | Angelo J Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| REF-GTECI-A-17, REF-GTECI-SY, REF-SSINS-0600, TASK-A-17, TASK-OR NUDOCS 7903260073 | |
| Download: ML19274E423 (13) | |
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MAR G 1979 Generic Task No. A-17 PROJECT: Generic Task No. A-17, Systems Interaction in Nuclear Power Plants
SUBJECT:
SUMMARY
OF MEETING WITH SANDIA LABORATORIES ON FEBRUARY 13-14, 1979 TO REVIEW PROGRESS ON SUB-TASKS 5 AND 6 FOR THE SECOND INTERIM REPORT On Tuesday and Wednesday, February 13-14, 1979, members of the NRC staff met with representatives of Sandia Laboratories in Albuquerque, New Mexico to discuss the progress of work on sub-tasks 5 and 6 which are to be reported in the second interim report due in March 1979.
These sub-tasks are concerned with the development of plant logic models and system models.
We also discussed, among othe, items, the format and substance of infonnation that will be presented to the ACRS Subcommittee on Plant Arrangements on April 4, 1979.
A sunnary of items discussed is presented in the following paragraphs.
A list of persons who attended the meeting is enclosed with this report.
1.
Use of Quantitative Risk Assessment Techniques We provided Sandia 1.acoratories with a copy of the Commission's policy statement dated January 18, 1979 on risk assessment and the Reactor Safety Study Report (WASH-1400), and discussed the use of WASH-1400 in the perfonnance of Task A-17.
Eventually, in accom-plishing sub-task 9 where interaction importance measurement techniques will be developed, it may be necessary to use probabilistic methods to assess the relative probability that given interactions may take place.
It is understood by all parties that these probabilistic assessments, and the use of WASH-1400 will be consistent with the Commission's policy statement.
Sandia Laboratories personnel have available and are familiar with the Risk Assessment Review Group Report (NUREG/CR-0400).
2.
Current Status of Subtasks 5 and 6 Sandia Laboratories has developed a set of fault trees for one plant condition.
There is a possibility that 60 fault trees would be needed to cover the matrix of plant operating modes, transient events, and safety functions. The 60 fault trees arise from the combinations of three safety functions, five plant operating modes, and four basic transient events.
However, Sandia personnel predict that there will 7903260 C3
. MAR G 1979 be only seven structurally different fault trees with about 18 slight variations among the seven fault trees. Enclosure 2 illus-trates the matrix of 60 fault trees.
In the development of Task A-17 we did not anticipate the extent of work that would be required to generate the fault trees and did not fully appreciate the large number of combinations of conditions.
Therefore, in order to accomplish Task A-17 within our stated time and funding, we agreed to restrict the effort in Phase I to the pressurized water reactor plant and systems logic models and decide later whether it is necessary to develop the same kind of fault trees for the boiling water reactor plant. We asked Sandia personnel to prepare an estimate of time and costs to accomplish the same tasks on the BWR's.
3.
Status cf the Second Interim Report Sandia personnel stated that the second interim report would be issued reasonably near the presently scheduled date of March 2, 1979. This report will present the results of sub-tasks 5 and 6 on the development of plant and system logic models. The report will be available for the ACRS Subcommittee meeting on April 4, 1979.
4.
Review of Licensee Event Reports, (LER), Included in the Zion Station Study on Systems Interaction Sandia Laborat] ries personnel presented the results of their survey of the LER's that were used in the Zion Station Study.
The survey covered the 67 LER's that were included in the Zion Station Study report. The survey revealed that there were 20 events in the list of 67 LER's that are covered in this task on systems interaction. provides a summary of the analysis of the Zion Station Study.
John Angelo, Ta Manager Generic Task No. A-17
Enclosures:
As Stated cc: Mr. Jack Hickman Division 4412 Sandia Laboratories P. 0. Box 5800 Albuquerque, New Mexico 87185
ENCLOSURE 1 ATTENDANCE LIST
-MEETING WITH SANDIA LABORATORIES ON FEBRUARY 13-14, 1979 SANDIA LALORATORIES NRC R. Easterling J. Angelo G. J. Boyd H. L. Ornstein W. R. Cramond Hulbert Li D. D. Carlson J. A. Norberg J. W. Hickman D. F. Ross D. McCloskey M. A. Taylor S. Asselin A. Oxfurth D. Murphy J. Olshinski
ENCLOSURE 2 POWER OPERATION STARTUP STANDBY HOT SHUTDOWN COLD SHUTDCWN P0 SU SB HS CS LOP PCS AOC NOR LOP PCS AOC NOR LOP PCS AOC NOR LOP PCS AOC NOR LOP PCS AOC NOR RS 3
4 !4 5
3 4
4 5
1 2
2 2
1 2
2 2
1 2
26 2
5(3) i
_p.
DHR 1
2 !
3 3
1 !2 3!3 1 l 2 3
3 1
2 3
3 1
2 3
3 3(2)
,i _
j i
I i
j 9 l 10 10 10 10(2) 8 8
1 2
2 2
RCPB 3
4 4
4 5
6 6; 6 7
8 j
FUtlCTIONS INITIATING EVENTS RS - REACTOR SUBCRITICALITY LOP - LOSS OF 0FFSITE POWER DHR - DECAY HEAT REMOVAL PCS - LOSS OF POWER CONVERSION SYSTEM CONDENSER RCPB - REACTOR COOLANT PRESSURE BOUNDARY A07 - ALL OTHER CONDITION II OCCURREllCES f40R - NORMAL SHUTDOWN INCLUDING SOME CONDITION II OCCURREtiCES
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EtiCLOSURE 3 ZION / FLUOR PIONEER LER STUDY
LER DISTRIBUTION (BY OPERATING P,0DE) 1.
POWER 15 2.
STARTUP 0
3.
HOT SHUTDOWN 3
4.
HOT STANDBY 1
5.
COLD SHUTDOWN 14 A)
SOLID WATER (10)
B)
STEAM BUBBLE (4) 6.
REFUELIrlG 2 2
7.
OTHER CONDITIONS 5
8.
UNKNOWN 27 67
LER DISTRIBUTION (BY INTERACTION CAUSE) 1.
FLOODIilC OR MOISTURE ACCUMULATION 18 2.
FIRE 6
3.
COMPOI1ENT FAILURES 6
4.
ELECTRICAL BUS FAILURE 6
A)
[10lSE (1)
B)
UNDERVOLTAGE (3)
C)
LOAD SHEDDING (2) 5.
HUMAt1 ERROR 18 A)
DURING MAltlTENAi1CE (4)
B)
DURif1G il0RMAL OPERATIONS (10)
C)
DURIt1G COMPONENT INSTALLATION (2)
D)
DESIGN (2)
s LER DISTRIBUTION (BY INTERACTION CAUSE) (CONT.)
6.
OVERIEMPERATURE 3
7.
MECHANICAL DAMAGE 2
8.
FREEZING 3
9.
UNKNOWN 4
10.
REFUELING (NOT COVERED) 1 67
LICENSEE EVENT REPORT REVIEW (ZION STUDY) 67 LER'S INTERACTI0il INTERACTION lilSUFFICIENT COVERED IN PRESENT NOT COVERED IrlFORMATI0il (4)
STUDY (20)
IN PRESEf1T STUDY (43)
IrlTERACTION DOES NOT INTERACTION OUTSIDE MEET STUDY C0f1 CEPT SCOPE OF STUDY (21)
(22)
STUDY I'ETHODOLOGY STUDY METHODOLOGY APPLICABLE (18) fl0T APPLICABLE (4)
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COVERED IN PRESENT STUDY VALVE PACKING LEAK ON MOV CAUSES MOTOR FAILURE SW PUMP SEAL LEAK CAUSES SHORTING 0F SW MOTOR OPERATOR HPCI STOP VALVE LEAKAGE FLOODS JUNCTION BOX CAUSING LOSS OF TWO BUSSES EFFLUENT JETS CAUSE MALFUNCTI0llS OF SAFETY / RELIEF VALVES HIGH MOISTURE LEVEL CAUSES FAILURE OF D!ESEL GENERATOR VOLTAGE REGULATOR
II.
fl0T COVERED IN PRESENT STUDY A.
INTERACTI0il DOES NOT f1EET STUDY C0ilCEPT OPERATOR ERROR CAUSES RCS OVERPRESSURIZATION WHILE SOLID (STARTING RCP WITH LARGE AT BETWEEN RCS AtlD S/G)
HPCI VALVE FAILS TO OPEN DUE TO MOISTURE Ifi CONTROL JUNCTION BOX (SIflGLE VALVE FAILURE)
COMPONENT FAILURE (CIRCUIT BREAKER FOR SAFEGUARDS BUS TRIPS CAUSING LETDOWil VALVE TO CLnSE, RESULTING IN RCS OVERPRESSURIZATI0il)
B.
li1TERACTION OUTSIDE OF SCOPE OF STUDY 1.
STUDY METHODOLOGY APPLICABLE OPERATOR ERROR CAUSES BORON DILUTI0il EJ TO Ui1 DETECTED SEC0ilDARY-T3-PRIMARY LEAL (
DESIGN ERROR - A Sli1GLE COMP 0i1ENT FAILURE IN LPCI SELECTION LOGIC COULD CAUSE FOUR RHR PUMPS TO PUMP TO A BROKEN lit!E 2.
STUDY METHODOLOGY NOT APPLICABLE PRESSURE VESSEL i!EAD DROPS DURIi1G REFUELIi1G WIRING ERROR IN STEAM PRESSURE AP CAUSES INCOMPLETE PROTECTI0il DESIGN ERROR - I.0SS OF CERTAlti ESF FEATURES CAUSED BY DIODE FAILURE (DUE TO INSUFFICIEtiT PRV)