ML20138B486
| ML20138B486 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 03/20/1986 |
| From: | Zimmerman S CAROLINA POWER & LIGHT CO. |
| To: | Muller D Office of Nuclear Reactor Regulation |
| References | |
| GL-84-09, GL-84-9, NLS-86-089, NLS-86-89, NUDOCS 8603250084 | |
| Download: ML20138B486 (29) | |
Text
CNLL Carolina Power & Light Company W 2 01986 SERIAL: NLS-86-089 Director of Nuclear Reactor Regulation Attention:
Mr. Dan Muller, Director BWR Project Directorate #2 Division of BWR Licensing United States Nuclear Regulatory Commission Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. DPR-71 & DPR-62 RECOMBINER CAPABILITY REQUIREMENTS NITROGEN SWITCHOVER SYSTEM
Dear Mr. Muller:
Carolina Power & Light Company (CP&L) met with members of the NRC staff on January 14,1986. The purpose of this meeting was to discuss several licensing issues concerning the Company's Brunswick facility. One of the issues discussed was the Nitrogen Switchover System which the Company has installed in both Brunswick units in order to meet the intent of the criteria set forth in Generic Letter 84-09.
During the course of the meeting, as reflected in the NRC meeting minutes issued February 18,1986, CP&L was requested to provide additional information necessary to support staff approval of the Brunswick system. Specifically, the Company was requested to submit a Probabilistic Risk Assessment (PRA) study which was discussed during the meeting. In addition, tne additional cost of literal compliance with Criterion 2 (of Generic Letter 84-09), i.e., installation of a new instrument system that uses a nitrogen supply or takes suction from the drywell atmosphere, was requested. The NRC staff will assess the cost estimate and the PRA study to determine if the additional cost is justified compared to any perceived additional margin of safety over the installed system.
An itemized estimate of the cost of modifying the instrument air system by installing a Nitrogen Pumpback System is provided in Attachment 1. The total estimated cost for this system is approximately $3 million. The cost of installing a pumpback system to achieve literal compliance with Criterion 2 of Generic Letter 84-09 was chosen for the estimate based on the availability of information, confidence that the system would operate effectively, and the Company's belief that if a detailed project proposal / evaluation were performed, a pumpback system would ultimately be the alternative selected to satisfy the scenario depicted by the NRC.
8603250004 B60320 PDR ADOCK 05000324 P
PDR Ob 411 Fayetteville street
- P. O Box 1551
- Raleigh. N C. 27602 l(g g
Mr. Dan Mullar NLS-86-089/Page 2
. provides the Probabilistic Risk Assessment of the Nitrogen Switchover System. Carolina Power & Light Company believes that the results of the attached PRA verify the Company's contention that the cost of installing an additional system to prohibit the scenario depicted by the NRC (i.e., an instrument airline rupture just prior to or concurrent with a loss of coolant accident) is not warranted. The probabilistic risks associated by the scenario depicted are significantly less than the current NRC approved technical specifications.
Should you have any questions regarding this submittal, please contact Mr. Stephen D.
Floyd at (919) 836-6901.
Yours very truly, S. R. Z' erman Manager Nuclear Licensing Section SRZ/RWS/ccc (3547RWS)
Attachments
- cc:
Mr. W. H. Ruland (NRC-BNP)
Dr. 3. Nelson Grace (NRC-RII)
Mr. E. Sylvester (NRC)
- Attachments with all cc's.
l l
ATTACHMENT 1 NLS-86-089 NITROGEN PUMPBACK SYSTEM COST ESTIMATE Component Cost
$ 507,000.00 Engineering Cost 876,000.00 Construction Cost 561,000<no Miscellaneous (H.P., Security, Overhead, etc.)
466,000.00 TOTAL PROJECT COST
$2,410,000.00 Assuming three years until mod installation, mod future cost is:
2,410,000 (1 + EE&C)N = 2,410,000 (1 + 0.06)3 = $2,870,349 (EE&C = Engineering and Construction Escalation Rate)
(3547RWs/ccc)
i l
ATTACHMENT 2 NLS-86-089 CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT PROBABILISTIC ANALYSIS OF LOCA-INDUCED AIR LINE BREAKS (3547RWS/ccc)
I
BRUNSWICK STEAM ELECTRIC PLANT NITROGEN STANDBY SYSTEM AIR LINE BREAK PROBABILISTIC ANALYSIS 1.
SUMMARY
Carolina Power & Light Company conducted a probabilistic analysis in order to resolve a question regarding whether the existing Brunswick Plant Nitrogen Switchover System satisfies the hydrogen control issue identified by 10 CFR 50.44(cX3Xii) and Generic Letter 84-09.
Specifically, the analysis was performed to address probabilistically the risk contributions of a LOCA induced instrument air line rupture within the drywell to the generation of a combustible mixture of hydrogen and oxygen following a core damage event.
This concern was addressed by the follov;bg approach.
First, a base case was run which determined that the probability of a combustible hydrogen-oxygen mixture in the drywell(due to core melt) during technical specification allowable de-inerted operating conditions was 5.67E-6/Rx. yr. Then the probability of developing a combustible hy(drogen-oxygen mixture due to a LOCA-induced air line rupture in the drywell following a LOCA induced core melt) was determined to be 5.03E-09/Rx. yr. Finally, a third case was run which determined that the probability of a combustible hydrogen-oxygen mixture in the drywell due to an open or broken instrument air line in the drywell and core damage from any of a number of events was 5.77E-8/Rx. yr.
Since the second and third probabilities were considerably less than the first, CP&L has concluded that the NRC's postulated scenario presents a negligible additional contributor to existing risk. That is, the de-inerting currently permitted by Technical Specifications is the controlling constraint and, therefore, design changes to prevent the NRC postulated scenario from occurring are not cost effective.
2.
DISCUSSION Event tree / fault tree methodology was used to determine the sequence frequencies and failure probability estimates.
The recently developed Brunswick plant safety significance computer model was used to determine the initiating event frequencies for the event trees. This model is essentially a BSEP specific event tree computer model which computes core
- j. damage frequency and the Veseley-Fussel importance of accident initiators and
' basic events. The basic event and initiator data for the model event trees is based on BSEP specific data where available from previous studies, on generic system fault trees, and on surrogate data from other industry sources where BSEP data was not available. Although it is not a full PRA, it does provide representative core damage and V-F importance data.
In this particular study, the model was employed to derive only the initiation i
frequencies for the event trees. The event trees and fault trees for the scenarios of concern are otherwise independent of the model.
(3547RWs/ccc )
This section details the methodology used to determine the sequence frequencies and failure probability estimates.
2.1 Base Case: Core Damage With De-Inerted Drywell In order to establish a baseline value for comparison, an event tree was developed which presents the likelihood of generation of a combustible mixture by core damage suffered with the unit at power and with a de-inerted drywell. This event tree is presented as Figure 1.
The sequence of events is as follows:
The unit is operating at power and suffers core damage. The frequency for a.
this event is the total core damage frequency directly from the BSEP safety significance model,2.07E-4/Rx. Yr., as shown in Appendix 1, Table A1.1.
b.
As a result of the core damage, hydrogen is generated within the containment in sufficient volume to form a combustible mixture if oxygen concentration exceeds the Technical Specification limit of 4 percent. For conservatism, this probability was estimated to be approximately 0.999.
c.
The drywell is not inerted and, therefore, oxygen concentration is approximately 20 percent. The probability of this occurrence is based on the allowed time for oxygen concentration to exceed 4 percent. Technical Specifications allow the containment atmosphere to exceed 4 percent for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after reaching 15 percent rated thermal power on startup and for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to reaching 15 percent rated thermal power on power reduction or shutdown.
A review of plant data for 1981 through 1985 gave an approximate average of 5 start-up/ shutdown cycles per year per unit where the allowed inerting procedures could have been used. Therefore, the probability of operating at power with a de-inerted containment is:
-2 5 (24 + 24) = 2.74 X 10 8766 The combustible mixture frequency of this base case is 5.67E-6.
2.2 LOCA Initiated Air Line Break and Core Damage The second portion of this study covers the concern that the unit is operating at power, that the drywell was inerted, and that the unit suffered a LOCA which causes core damage and an instrument air line break in the drywell. Figure 2 is a schematic representation of the situation of concern, and Figure 3 shows the event tree and supporting fault trees.
The sequence of events is as follows:
The unit is operating at power with an inerted drywell and suffers an a.
l initiating event LOCA which causes core damage. The frequency for this initiating event (7.2E-6/Rx. Yr.) was derived from the safety significance model(Appendix 1).
(3547RWs/pgp )
b.
As a result of the LOCA, one of the instrument air lines within the drywell ruptures. The probability of this event is estimated to be 0.999. This is a conservative estimate as the rupture is dependent on the location and energy of the LOCA as well as pipe positions within the drywell.
c.
As a result of the core damage, hydrogen is generated within the containment in sufficient volume to form a combustible mixture if oxygen concentration exceeds 4 percent. Again for conservatism, this probability was estimated to be approximately 0.999.
d.
In order for the system to pump oxygen into the drywell through the break, the isolation valve must remain open. This could be caused by failure of the Containment Isolation Signal (CIS) logic and failure of the operator to manually close the valve or by the valve sticking in the open position.
From the fault tree, the likelihood of this is 7.0E-4. The fault tree data sources are presented in Appendix 2.
The sequence resulting in Class 4, combustible mixture, is the one of interest.
The frequency of this sequence is calculated to be 5.03E-9 per reactor year.
2.3 Open Air Line and Ccre Damage The third protion of this study covers the concern that the unit is operating at power, that the drywell is inerted, that an instrument air line is open in the drywell, and that the unit suffered core damage from any of a number of events.
Figure 4 shows the event tree and supporting fault tree.
The sequence of events is as follows:
a.
The unit is operating at power with an inerted drywell and suffers core damage. The frequency for this initiating event,2.07E-4, again is directly from the BSEP safety significance model as shown in Appendix 1.
b.
As a result of the core damage, hydrogen is generated within the containment in sufficient volume to form a combustible mixture if oxygen concentration exceeds 4 percent. Again, the probability is estimated as 0.999.
c.
In order for the oxygen concentration to exceed 4 percent, the air line must be open to containment and the isolation valve on that line must be open.
Note that in this sequence, the open air line could result from pipe breaks other than chat caused by the LOCA or it could result from the line being left disconnected through human error. In addition, this event does not consider the possibility of the CIS logic closing the valve because the open air line could have occurred prior to the core melt initiating event. From the fault tree, the probability for this event is 7.3E-5. Supporting data is listed in Appendix 3.
The Class 3 sequence, combustible mixture, is the one of interest for this tree.
The frequency of this sequence is calculated to be 5.77E-8/Rx. Yr.
(3547RWs/pgp )
Since this sequence is based on the total core damage frequency and allows for human error in leaving the air line disconnected, it is reasonable that it shculd have a higher frequency than the second case.
3.
CONCLUSION The concern that the existing standby nitrogen system at BSEP could introduce oxygen into the drywell was analyzed probabilistically using event tree / fault tree methodology.
The analysis demonstrates that the likelihood of generating a combustible mixture of hydrogen and oxygen within the drywell as a result of an instrument air line break in conjunction with a core damage event, is less than that which is possible as a result of being de-inerted (as allowed by Technicai Specifications) and having a core damage event.
The results of the analysis are listed below:
Percent of Scenario Frequency Total Frequency De-Inerted Drywell and Core Damage 5.67E-6/Rx. Yr.
98.91 LOCA Initiated Air Line Break and 5.03E-9/Rx. Yr.
0.09 Core Damage Open Air Line and Core Damage 5.77E-8/Rx. Yr.
1.00 Total Frequency 5.73E-6 (3547RWS/pgp)
S QUENCE CORE dam E HIQi HYIROGN DRVEL llERTED CUSS N FREQUENCY CONCDCRATION AT P0lER 1
2.81E-7 2
5.67E-9
- 2. M -4 g,999 3
2.81E-4 2.7 0 2 4
5.67E-6 CLASS:
- 1. NO H2,82 ( 4X
- 2. NO H2,82 > 4%
- 3. HIQi H2,82 ( 4%
- 4. COPSUSTIBLE MIXTulE FIG.
1 DATE: 3-7-96 l TITLE: CORE DAME PLUS DE-Il(RTED IRYlELL EVENT TRE lFN:02FTH l DRN. BY:M).
4 r
l i
e 1
I I Att4)NCl4TCR 1.
Atal ERS
/ \\
(B[l... :
6 6
N-M l
l closes cN CIS closes cN ciS NON-iNTERRUPTIBLE M
M NON-INTERRUPTi BLE ItET. AIR 3y.5261 sV-5262 IPET. AIR x
,R shM v v PELIPSTIC y
EQU!FtO R._3 e
FIG.
2 ten.sv:g care: 2-14-86 riitz: NiTRocEn stasiv systoi a:R tim 8REnx rn:o24rTca
i AIMIE HY UA CLASS FREQUENCY C
ION g
1 7.2K-12
- g 2
7.19E-89 7.2C-6/YR 1
7.19E-99 7 ' E'4 3
5.93E-12 g,g 2
7.1K-86 0.999
' E-4 4
s.e3E-e9 LOCA PL1)S AIR LIE BREAR EVENT TRE l
s B
e CLASS: 1. NO H2,02 ( 4%
- 2. HICH H2,02 ( W.
l
- 3. NO H2,02 ) W.
- 4. CCMUSTIBLE MIXTURE l
I B
e IS01ATgUALVE 7,g 4 UGLUE NOT DEMRCIZED 7 E-4 UALVE STICHS OPEN OPERATOR FAILS TO TAE ACTION LOGIC FAILS 1.35E-5 BOTH AMLYZERS OPERATdRFAILS FAIL TO TAE ACTION 6
6 DIV. I FAILS TO 02 ANALYZER DETECT 2.g,2 1E-3 FA S O
O DIU. 11 FAILS TO 02 ASLYZER ISOLATE
!."#S ET 2
FIG.
3 n
NTE.3-15-86l TITLE:
LOCA + AIR Life EREAR EUDJT TEE & FAULT TRE l R4: 024FTBA l[Mt. BV) W i
/
i
I 1
CORE NteE PLUS OPEN AIR Lite EVENT TRE HIGI H2 02 CONCD4TRATION SEQUENCE CCRE E LT eggg CCtCDITRATICN
>4%
FREQUDCY
~
2.07E-4 RX. VR.
g,999 2
2.07E-4 2.
3 5.77E-9 CLASS:
- 1. to H2 l
- 2. HICH H2, 02 ( 4%
- 3. COMBUSTIBLE MIXTURE l
5 e
i I
8 e
s I
l 02 ) 4 % CCNCEbTRATICN l 2.79E-4 l
l AIR Life OPEN ISOLATION UALVE TO CCt(TAltt04T OPEN o
OPERATOR FAILS TO TAE ACTION AIR hut 9N VALVE Lite ERROR FAILS EREAHS AIR Lite OPEN 2g.2 LEFT DISCCtfECTED 7.E-4 1.?E-2 BOTH AthlVZERS OPEPATh FAILS Fall TO TAFE ACTICN b
6 6
LIV. I FAILS TO 02 ANALYZER DETECT FAILS 1E-3 2.9E-2 DIU. !!
FAILS TO 02 ANALYZER ISOLATE FAILS VALUE 2.9E-2 5E-3 FIG.
4 DATE:3-14-86 l TITLE:
CORE DAt#E + OPEN AIR Lite EVENT TRE Ate FAULT TRE l FN: 024FTAA l DRN. BY '#/7
/
I q
(
APPENDIX 1 l
l l
APPENDfX 1 Table A1.1 lists the core damage frequency and Vesely-Fussel Importances to core damage of the basic events (BE) calculated by the BSEP safety significance model.
Table A1.2 lists the Basic Events.
The Vesely-Fussel Inportance = Total Contribution to C.D.F. from B.E.
Total C.D.F.
Therefore the Total Contribution to C.D.F.
from B.E. = (V-F Importance)
(Total C.D.F.)
for Large IDCA, A.
V-F I = 0.2762E-01 from Table A1.1 A contribution to C.D.F. = (0.2762E-01) (2.0651E-04) = 5.7038E-6 for Medium IDCA. S1 V-F I = 0.5136E-02 from Table A1.1
-6 S1 contribution to C.D.F. = (0.5136E-02) (2.0651E-04) = 1.06X10 for Small IDCA, S2 V-F I = 0.1695E-02 from Table A1.1
_7 S2 contribution to C.D.F. = (0.1695E-02) (2.0651E-04) = 3.5K10 for Large IDCA outside containment, ADUT V-F I = 0.4485E-03 AOUT contribution to C.D.F. = (0.4485E-03) (2.0651E-04) = 9.262E-8 Total IDCA contribution to C.D.F. = 7.20 E-6 i
i
- f-
\\
TABLE Al.1 CORE DAMAGE
SUMMARY
USING POINT ESTIMATION l
RUN NO.=
1 BY= OFD DATE= 091185 The frequency of core damage for class #
1 7.2391E-05 The frequency of core damage for class 8 2
4.9836E-05 The frequency of cora damage for class #
3 5.2228E-07 The frequency of core damage for elaan #
4 8.3672E-05 The frequency of core damage for clase #
5 A.4208E-08 Tha total frequency of core damage 2.0651E-04 POINT ESTIMATION OF RASIC EVENT IMPORTANCES TO CORE DAMAGE RUN NO.=
1 BY= OFD DATE= 09118F RASIC TOTAL CORE C!. ASS CLASS CLASS CLASS CLASS EVENT DAMAC.E 81 82 8 3 84 85 RPS 0.6630E+00 0.7350E+00 0.0000E+00 0.8577E-01 0.1000E+01 0.0000E+00 TT 0.5969E+00 0.7006E+00 0.3080E+00 0.6493E-01 0.6832E+00 0.0000E+00 SLC 0.4488E+00 0.1454E+00 0.0000E+00 0.0000E+00 0.9818E+00 0.0000E+00 OP1 0.4155K+00 0.4910R+00 0.2156E+00 0.4545E-01 0.4721E+00 0.0000E+00 HPCI 0.3446E+00 0.8897E+00 0.3728E-01 0.7238E+00 0.5413E-01 0.0000E+00 RNA 0.2383E+00 0.0000E+00 0.9743E+00 0.0000E+00 0.7A72E-02 0.0000E+00 MSIV 0.2028t+00 0.4530E-01 0.2136E+00 0.6743E-02 0.3341E+00 0.0000E+00 PCS 0.1656E+00 0.0000E+00 0.6861E+00 0.0000E+00 0.0000E+00 0.00GOE+00 NTDP 0.1457E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.3596E+00~0.0000E+00 TC 0.1278E+00 0.4461E-01 0.2145E+00 0.3007E-02 0.1490E+00 0.0000E+00 LP 0.8962E-01 0.1575E+00 0.9811E-01 0.4129E-01 0.2625E-01 0.0000E+00 COP 0.8608E-01 0.1566E+00 0.9581E-01 0.3119E-01 0.1970E-01 0.0000E+00 FMS 0.8411E-01 0.A538E-01 0.1981E+00 0.5221E-02 0.1572E-01 0.0000E+00 49 0.7553E-01 0.1539E+00 0.8898E-01 0.1188E-02 0.2224E-03 0.0000E+00 RCIC 0.6748E-01 0.1448E+00 0.6923E-OS 0.4917E-02 0.0000E+00 0.0000E+00 TM 0.5957E-01 0.1573E-01 0.3640E-01 0.2255E-02 0.1117E+00 0.0000E+00 TDP 0.4907E-01 0.1346E+00 0.7867E-03 0.6687E+00 0.0000E+00 0.0000E+00 MS 0.4756E-01 0.3482E-02 0.1920E+00 0.0000E+00 0.0000E+00 0.0000E+00 AMP 0.4066E-01 0.1111E+00 0.7055E-02 0.4917E-02 0.0000E+00 0.0000E+00 DCR 0.2843E-01 0.7650E-01 0.6689E-02 0.0000E+00 0.0000E+00 0.0000E+00 A
0.2762E-01 0.0000E+00 0.1123E+00 0.2019E+00 0.0000E+00 0.0000E+00 SRVC 0.2682E-01 0.6074E-01 0.2154E-02 0.3958E-01 0.1212E-01 0.0000E+00 TF 0.2212E-01 0.2533E-01 0.1033E-01 0.2255E-02 0.2652E-01 0.0000E+00 TT 0.2154E-01 0.5235E-01 0.1310E-01 0.1436E-05 0.7448E-04 0.0000E+00 DCM 0.1695E-01 0.4460E-01 0.5471E-02 0.0000E+00 0.0000E+00 0.0000E+00 ALP 0.1233E-01 0.3163E-01 0.0000E+00 0.2430E+00 0.0000E+00 0.1000E+01 CS 0.5792E-02 0.7661E-03 0.1457E-01 0.2430E+00 0.0000E+00 0.1000E+01 LPCI 0.5685E-02 0.7661E-03 0.1813E-01 0.2430E+00 0.0000E+00 0.1000E+01 51 0.5136E-02 0.1026E-03 0.1251E-01 0.6794E+00 0.8938E-03 0.0000E+00 CHS 0.4773E-02 0.1337E-02 0.9706E-03 0.2027E-03 0.20045-01 0.0000E+00 52 0.169ME-02 0.2737E-03 0.2571E-02 0.4963E-02 0.2383E-02 0.0000E+00 HDP 0.8629E-03 0.2462E-02 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 TRP 0.4778E-03 0.1338E-03 0.9716E-04 0.2030E-04 0.1005E-02 0.0000E+00 AOUT 0.44aME-01 0.0000E+00 0.8850E-04 0.0000E+00 0.0000E+00 0.1000E+0!
OP2 0.3407E-03 0.5724E-04 0.1203E-02 0.1436E-05 0.7440E-04 0.0000E+00 SRVO 0.2844E-03 0.0000E+00 0.4005E-03 0.1860E-02 0.4517E-03 0.0000E+00 BD 0.2339E-03 0.0000E+00 0.0000E+00 0.0000E+00 0.5772E-03 0.0000E+00 RPT 0.1830E-03 0.0000E+00 0.0000E+00 0.7237E-01 0.0000E+00 0.0000E+00 VS 0.3402E-05 0.0000E+00 0.0000E+00 0.1345E-02 0.0000E+00 0.0000E+00 Page A1.2
TABLE A1.2 ASSREVIATIONS
. TT Turtdne Trip 1
2.
MS M,enuel Sheldown 3.
TP Trene4ent. Laos of Pendweger Accident e.
Tu trenoient. MSiv Cb
~
frenelent. Lese of Condeneer vaa.-
Init18 tor S.
TC e.
_ Lees of offeate Pe.e, Ces,sete Group 7*
Tl 1renelent, inadvertently Open Relief Velve j
s.
A Large LOCA f
9.
St Medisse LOCA 1
- 11. AOUT j
- 12. RPS Reester Protection Systees
- 13. FWS Peegreter System Ie. SRvo Sr. Open When Chenensed
- 15. SRVC ga That Opened Rectose
- 16. opt p Molntenne Pendweter en
- 17. TOP Turtdne typese Systene
- 10. CHS heenediate AvailehHity Condenser se Hest Sink
- 19. RCIC RCIC
- 20. HPCI HPCI
- 22. TDP Operecer Depreneurisee _Peteery Systeen
- 23. ALP Afternete _ Lee _ Press. Sources (Condeneste Pumps. HTR Orsin Ptsope frees CST Thrw Condensert) 24 RHR Reenduel Heat Removal
Condenoste Systeel
- 27. SLC StoneRey Liquid Centre 4
- 28. MOP Maintain Wourfaed Conditlen (Dependent en Betterlee)
- 29. CS C.re Sprey M.
RPT R_actre. Pusep Tripped
- 31. LPCI p @ e Caelant171
- 33. 50 Beren not Wed HPCB 6 P. W. Centrolled M.
OP2 Serty Scress by W ( Aner luttV) t
- 39. VS Vapor Segspreseien (Stense Condensed Suppreselon Peel)
- 30. R0P Reenvery Offette _ Power
- 37. OC Oleoel Generatore 3e. oCR oC_ Pe, for RCIC
- 39. OCH g Power for HPCI l
t l
Page A1.3 l
\\
l
G e
APPENDIX 2 t
i
APPENDIX 2
" ISOLATION VALVE OPEN" FAULT TREE DATA SUPPORT EVENT DESCRIPTION MODEL PROBABILITY Logic Fails 1.35-E Fault Tree Page A2.2 IA containment isolation valve fails open 7.0E-04 NUREG/CR-4217. Table IX-A Page A3.4 & 5 0xygen analyzer I fails 2.9E-2 NPRDS BSEP, Page A3.6 0xygen analyzer 2 fails 2.9E-2 NPRDS BSEP, Page A3.6 Human error - operator fails to detect high 1.0E-03 NUREG/CR-1278 Page A3.7 oxygen alarm Human error - operator fails to close IA 5.0E-03 NUREG/CR-1278, Page A3.8 isolation valve E
- s M
~~
I T
LCW LIVEL
..B
.A NO314-4 NO31C-4
"='
-=
- ,=
3 05,
. g=.. Dem..
H7A HBA R18C i
O p iKISC
=3-U5262
=
o o
FRCH 1-FP-5889
?IR1 2
' SU-4262 tog g NB313-4 NO31 )-4 a
==
mCIE
= HBB FROM LL-90046 SH ! A-6 PM 84-195
=HB4
=
=
)
N D
l hAf@CATE LOClC FAILS TO DEDGCIE UALUE 1.35E-5 O
_ mA, _
=_
FAILS FAILS HIQ4 DRYlELL PRESS.
LOW RX. PRESS.
FAILS FAILS 1E-3 1E-3 O
aSSU= rm n*S amusiS mA mB HBA HSB NO314-4 NO315-4 NW1C-4 NO31D-4 FAILS FAILS FAILS FAILS FAILS FAILS FAILS FAILS TO TO TO TO TO TO TO TO CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE CLOSE
- )
l C
CCetENTS COMP 0 TENTS ugyg yy SCURCE UNAUA BILITY WA & WB 2.6K-4 TA A
-1 7'IE'8 7.1K-8 HBA & HBB NO31A-4 &
EDC-30 REP 4.22E-9 N031C-4 6.5E-5 PA E E-2 NO315-4 &
4.22E-9 NO31D-4 8.0E-8/h SNPS PRA DOMimNT 1.35E-5 3-05262 7=7du TABLE A.2-1 CMIBUTM PAGE A2.2 xisc & xlao 1.82E-le DATE: 3-3-86 TITLE: CORE SPRAY LOGIC AMLYSIS FN: 02fTD DRN.BY:g/ff[
l
/
e e
APPENDIX 3 9
1
APPENDIX 3 02 > 4% CONCENTRATION FAULT TREE DATA SUPORT EVENT DESCRIPTION MODEL PROBABILITY SOURCE Instrument air line break 2.0E-02 NUREG/CR 2728 Table 5.3-1 Human error - IA line lef t disconnected
- 1. 7 E-0 2 NUREG/CR 1278, Page A3.2 LA containment isolation valve fails open 7.0E-0 4 NUREG/CR 4217. Table IX-A Pg. A3.4&S
~
0xygen analyzer 1 fails 2.9E-2 NPRDS BSEP. Page A3.6 0xygen analyzer 2 fails 2.9E-2 NPRDS BSEP. Page A3.6 Human error - operator fails to detect high 1.0E-03 NUREC/CR-1278. Page A3.7 oxygen alarm l
Human error - operator fails to close 1A 5.0E-03 NUREG/CR-1278, Page A3.8 isolation valve 1
b e
1
i 1
Reconnecting instrument Air Tubing After
~
Testing, Maintenance, or Calibration PRMKIN WOIESKET Page of 1
Exercise No.
C Problem No.
Analyst:
K. Paul 2
Performance Shaping Factors:
Instructions Experience Stress Level Tagging Level Written:
<10 items X
<6 months Low I
>10 items
>6 months X
Optimum X
2 Oral Mod. High 3
None High NA 3
Written Procedure
- 4. Dependence
- 5. Potential Error
- 6. Table No.
- 7. Tabled 8.Stres52
- 9. Adjusted
- 10. Comments *
,O Step No. or Task
& Item No.
HEP &
Skill HEP g
Description UCBs Factor F
A Failure to use 20-6 05 Test or g
N Written Procedures
- 6 & #7
.3 Calibration Maintenance 8
Failure to use -
20-6 5
Checkoff Provision da ProperIy C
Omit Step, Checkoff 20-7 001 Used Proper 1y
- 1 j
~,
' ~
D Omit Step, Checkotf 20-7
.003 Used leproperly
- 3 E
. Omit Step, Procedures 20-7 05 Not Used
- 5 P(F ) Testing, Calibration.005 P(F) Maintenance 017
- Cite studies, it available, to back up any disagreement with the stated HEP and EF in the handbook.
Figure A-1 Worksheet To Be Used For Exercises No. 3-6
' " ~,
(3547RWS/pgp) 1 1
Testing Calibration A
.95
.05 B
E
.95
.5
.95
.05 C
D S3
.999.001
.99
.003 F3 1
1 2
2 P(F) = (0.05 x.05) + (.95 x.5 x.003) + (.95 x.95 x.001)
=.0048275
~.005 Maintenance A =.3 P(F) = (.3 x.05) + (.97 x.5 x.003) + (.97 x.95 x.001)
=.0173765 g.017 Page A3.3
W u g s c, / c_ g - 4 2i 7
)
TABLE IX-A SWR:
DEMANO-0EPEN0ENT, CATASTROPHIC FAILURES--FAILURE TO OPERATE ON DEMAND (A K)
Average Failure-Rate Estimate--2.35 x 10~3 (8.32 x 10~4)
Failure-Rate Rank Factor Category Description R
Adjustment i
VTYPE 1
Angle 13.35 1.33 (0.76) 2 Butterfly 1.20 (0.49) 3 Plug 0.44 (0.35) 4 Diaphragm 4.14 (3.37) 5 Gate 1.27 (0.45) 6 Globe 0.87 (0.37) 78 Relief / safety 0.31 (0.45) 2 SIZE 1
<2 fnches 6.74 0.91 (0.28)
)
2 2-10 inches 0.56 (0.14) 3 10-30 inches
.0.54 (0.14) 4
>30 inches 3.64 (1.73) 3 SYSTEM 1
Containment 4.53 0.36 (0.17) 2 Nuclear 1.46 (0.48) 3 Power conversion 1.62 (0.52)..-
4 Safety 1.63 (0.77) 5 Process auxiliary 0.73 (0.59) 4 OTYPE 1
Air 1.63 1.17 (0.42) 2 Solenoid
- 1.17 (0.89) 3 Motor 0.95 (0.36) 4 Chain 0.72 (0.44) 5 Manual 1.07'(1.18)
Note:
Values in parentheses are stsndard deviations.
)
Page A3.4 33
INSTRUMENT AIR CONTAINMENT ISOLATION VALVE Valve Type: GATE (Assumed)
Valve Size: 2" System: Containment Operator Type: Solenoid (Direct Acting, Fail Close)
Manufacturer: Valcor Model No.: V-526-5683-6 Using Table IX-A of NUREG/CR-4217 (Attached)
Average Failure on Demand: 2.35E-03 Factor Failure Rate Adjustment V TYPE 1.27 SIZE
.56 SYSTEM
.36 O TYPE 1.17 UD = (2.35E-03)(1.27)(.56)(.36)(1.17)
UD = 7.04E-04 l
l l
1 i
Page A3.5 (3547RWs/pgp )
'10 G7:44 21 FEB 1986 225 CMA-2 02 Analyzer Failure Rates from NPRDS
[
- ol Calendar Hours:
63,408 ret 01 Estimated Operating Hoursa 46,775 Tctol Number of Failures Included:
23 No.
Failures per Million MTBF Oodo Translation Fail Calendar Est Operating Calendar Est Operat ing Hours Hours Hours Hours Ov::rc11 23 362.738 491.716 2757 2034 Fce all failures included, Mean Restovation Tiano (hours):
81 With Standard Deviation of a
71 Average Out-of-Service Hours :
253' With Standard Deviation of a
341 Thio data is calculated for failures discovered and hours accumulated through quarter 85-3 Thero were 5 records in the 2C hit list and 5 were used in these calculations.
02 Analyzer MTBF = 2757 hours0.0319 days <br />0.766 hours <br />0.00456 weeks <br />0.00105 months <br /> Mean Restoration Time = 81 hours9.375e-4 days <br />0.0225 hours <br />1.339286e-4 weeks <br />3.08205e-5 months <br /> = T A=T 1
MTBF
-2 A = 81 1
= 2.93X10-2 @ 2.9X10 2757
-2 A 2 2.9X10 Page A3.6
Failure to Detect and Diagnose High Oxygen Alarm in Control Room Within 30 Minutes RIIMKEN WOBESEET Page of 1
Exercise No.
A Problem No.
Analyst:
K. Paul 2
Performance Shaping Factors:
Instructions Experience Stress Level Tagging tevel Written:
<10 items
<6 months Low I
>10 items
>6 months X
Optimum X
2 Oral Nod. High 3
None X
High NA X
y 3
Written Procedure
- 4. Dependence
- 5. Potential Error
- 6. Table No.
- 7. Tabled
- 8. Stress /
- 9. Adjusted
- 10. Pn==<nts*
Step No. or Task
& ites No.
EP &
SkIii HEP Description UCBs Factor pu A
20-3
.001 Nominal Model
- 4 for Diagnosis l
1
' Cite studies, if available, to back up any disagreement with the stated E P and EF in the handbook.
Figure A-1 Worksheet To Be Used For Exercise Nos. 3-6 s
i (3547RWS/ccc) i
1 Failure to Close Instrument Air in lsolation Valve From Control Room PROBLEM M SE ET Page of 1
Exercise No.
B Problem No.
Analyst:
K. Paul 2
Performance Shaping Factors instructions Experience Stress Level Tagging Level Written:
<10 items
<6 months Low I
>10 items
>6 months Optimum 2
Oral Nod. High 3
None High NA 7
3 Written Procedure
- 4. Dependence
- 5. Potential Error
- 6. Table No.
- 7. Tabled
- 8. Stress /
- 9. Adjusted
- 10. Comments
- Step No. or Task
& item No.
EP &
Skill EP p
Description UC8s Factor F
A Failure to Use 20-6 005 Written Procedures
- 4 8
tallure to Use 20-6 5
Checkoff Provislon
- 8 Properiy C
Omit Step, Checkoff 20-7 001 Used Proper 1y
- 1 D
Omit Step, Checkoff 20-7 003 Used improperly
- 3 E
Omit Step, Procedures 20-7 05 Not Used
- 5 F
Error of Commission 20-12 003
- 10 P(F )
005
=
- Cite studies, if available, to back up any disagreement with the stated HEP and EF in the handbook.
Figure A-1 Worksheet To Be Used For Exercises No. 3-6 (3547RWS/pgp)
A
.995 -
.005 B
E
.95
.5
.95
.05 C
D
.999
.001
.997
.003
.997
.003 F5 F
F F
.997
.003 2
2 3
3 4
l 3
F 1
1 I
P(F) = (.005 x.05) + (.005 x.95 x.003) + (.995 x.5 x.003)
[
+ (.995 x.95 x.001) + (.995 x.95 x.999 x.003)
=.0055349
~.005 s
v i
i j
Page A3.9
,. ~....,
-