ML20239A089
| ML20239A089 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 08/27/1987 |
| From: | Croley B, Humenansky D, Moyer R SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | |
| Shared Package | |
| ML20238F564 | List: |
| References | |
| NUDOCS 8709170072 | |
| Download: ML20239A089 (27) | |
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EX1ANDED AUGMENTED SYSTEM REVIEW AND TEST PROGRAM (EXPANDED ASRTP)
EVALUATION OF THE NON-NUCLEAR INSTRUMENTATION SYSTEM SUBMITTED BY:
e eca
/
-,A v-DATE:
88'S 6 -8'T' RICHARD M0YER
/
TEAM LEADER CONCURRENCE:
iM '~b We DATE:
8 26-O
/ DAVID HUMENANSKY
/l 7 EXPANDED ASRTP PROGRAM MAN W R l
DATE: )I'.7 d" CONCURRENCE:
/
B0B CROLEY
/
DIRECTOR, NUCLEAR TECHNICAL SERVICES i
)
eg9174%M SN f e
G 1-
TABLE OF CONTENTS Pace Number
1.0 INTRODUCTION
3 2.0 PURPOSE 4
l 3.0 SCOPE 5
l 4.0 OVERALL RESULTS AND CONCLUSIONS 6
5.0 SPECIFIC CONCERNS 8
5.1 Acknowledged (Valid) Concerns 5.2 Open (Potential) Concerns 6.0 ATTACHMENTS 9
6.1 List of Documents Reviewed 6.2 Status of RIs 6.3 Detailed Observations - Requests for Information I
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EXPANDED AUGMENTED SYSTEM REVIEW AND TEST PROGRAM EVALUATION OF THE NON-NUCLEAR INSTRUMENTATION SYSTEM
1.0 INTRODUCTION
The Rancho Seco Expanded Augmented System Review and Test Program
[ASRTP] evaluation effort involves an assessment of the effectiveness of the System Review and Test Program (SRTP] and an analysis of the adequacy of ongoing programs to ensure that systems will continue to function properly after restart.
The Expanded ASRTP is a detailed system by system review of the SRTP as implemented on 33 selected systems and an in-depth review of the engineering, modification, maintenance, operations, surveillance, inservice testing, and quality programs.
It also conducts a review, on a sampling basis, of many of the numerous ongoing verification and review programs at Rancho Seco.
Six multi-disciplined teams composed of knowledgeable and experienced personnel are tasked with performing the Expanded ASRTP.
Each multi-disciplined team consists of dedicated personnel with appropriate backgrounds to evaluate the operations, maintenance, engineering, and design functional areas.
Independence, perspective, and industry standards provided by team members with consultants, architect engineer and vendor backgrounds are joined with the specific plant knowledge of SMUD team members.
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Each team performs an evaluation on a selected system using the same j
fundamental evaluation techniques employed by the NRC in the ASRTP l
inspection.
System Status Reports are used as the primary source of leads for the teams.
They are auge.ented with references to
)
available source and design bases documents as needed.
Team synergism and communication is emphasized during the process in order to enhance the evaluation.
Each team prepares a report for j
each completed selected system evaluated.
This report is for the i
Non-Nuclear Instrumentation (NNI) system.
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i 2.0 PURPOSE The objectives of the Expanded ASRTP evaluation are to (1) assess the adequacy of activities and systems in support of restart and (2) evaluate the effectiveness of established programs for ensuring safety during plant operation after restart.
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3.0 SC0oE To accomplish the first objective, the Control Systems team evaluated the Non-Nuclear Instrumentation system to determine whether:
1.
The system was capable of performing the safety functions required by its design bases.
2.
Testing was adequate to demonstrate that the system would perform all of the safety functions required.
3.
System maintenance was adequate to ensure system operability under postulated accident conditions.
4.
Operator and maintenance technician training was adequate to ensure proper operations and maintenance of the system.
5.
Human factors relative to the., stem and the system's supporting procedures were adequate to ensure proper system operations under normal and accident conditions.
To accomplish the second objective, the team reviewed the programs as implemented for the system in the following functional areas:
1.
Systems Design and Change Control 2.
Maintenance
]
3.
Operations and Training 4.
Surveillance and Inservice Testing 5.
Quality Assurance 6.
Engineering Programs i
The team reviewed a number of documents in preparation for and i
during the Expanded ASRTP evaluation.
This list of documents is found in Attachment 6.1.
The primary source of leads for the team were the problems identified in the NNI System Status Report.
Various source documents such as the USAR and Technical Specifications and available design bases documents were reviewed as needed to augment the information needed by the team.
The evaluation of the NNI system included a review of pertinent portions of support systems that must be functional in order for the NNI system to meet its design objectives.. _ - _ _ _ _ _ - - _ _
1 4.0 OVERALL RESULTS AND CONCLUSIONS The more significant issues identified pertaining to the adequacy of the SRTP and the effectiveness of programs to ensure continued safe I
operations after restart are summarized below.
The summary focuses l
on the weaknesses identified during the evaluation..3 provides detailed findings by providing the Request for Information (RI) forms that are used by the Expanded ASRTP teams to identify potential concerns during the evaluation.
Section 5.0 lists the specific concerns identified by the teams.
The numbers in brackets after each individual summary or concern refer to the corresponding RIs in Attachment 6.3.
4.1 Engineering Design 4.1.1 NNI instrumentation may be calibrated to incorrect setpoints.
The Process Standards contain a listing of selected instrument setpoints but do not contain process control and module settings.
Process Standards do not reference supporting documentation and the plant could not i
provide criteria for inclusion or exclusion of setpoints in j
these documents.
Directions for addressing setpoints in the procedures for generation, implementation, and turnover of modification packages do not exist.
In addition, no guidance exists on analyzing, documenting or transd ttir.g setpoints and disseminating setpoints to setpoint and training documents.
The plant was also unable to show existence of loop error analysis for setpoints.
These items, coupled with numerous discrepancies in design documents such as Process Standards and the System Design Bases Report, results in uncertainty with respect to setpoints in meeting USAR, Technical Specifications, regulatory and functional requirements for NNI and other systems. This concern was similarly.noted in the EASRTP report for ICS (RI-036) and the team suspects setpoints to be a generic problem. (RI-150) 4.2 Testing I
4.2.1 The NNI functional test may be inadequate to verify errors in the system which may have resulted due to the massive rework of terminations resulting from an identified cause of the December 26, 1985 trip.
The termination rework is identified in NNI System Status Report Problem #13.
Quality Control inspection was requested and performed on the-(
quality of the terminations only.
Some termination errors have recently been discovered and documented in the ICS system and additional errors may exist in NNI.
The team expressed concern that these types of errors may go undetected if the NNI. functional test is not comprehensive enough to validate the termination rework and could lead to plant control malfunctions.
This issue was similarly documented in the Expanded ASRTP report for ICS.
(RI-154) l
OVERALL RESULTS AND CONCLUSIONS (Continued) 4.3 Human Factors 4.3.1 Many variations exist in the way level indication is displayed for the Once Thru Steam Generators (OTSGs) as found on the Control Room consoles, remote shutdown panel, boron analyzer panel, and Technical Support Center displays.
Display variations include ranges, engineering units, and parameters (compensated vs. uncompensated
{
level).
The team expressed concern that operator errors may result during high stress situations if operators had to refer to various indications for OTSG level which were not directly compatible. (RI-142) l
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5.0 SPECIFIC CONCERNS A list of the specific concerns the Expanded ASRTP team believes are new concerns not previously identified for resolution follows:
5.1 Acknowledged (Valid) Concerns 5.1.1 The Automatic Bus Transfers (ABTs) are designed such that a situation could exist where NNI AC loads are lost but NNI DC loads remain energized causing uncertainty in plant functional control. (RI-129) 5.1.2 Testing of NNI power supply capacity and coordination of shunt switches Si and S2 is inadequate. (RI-139) 5.1.3 Level indications for Once Thru Steam Generators (OTSGs) may cause operator confusion due to variations in ranges, engir.eering units, and displayed parameters (compensated vs.
l uncompensated level).
(RI-142) 5.1.4 Non-Nuclear Instrumentation devices may be calibrated to incorrect setpoints. (RI-150) 5.1.5 Preventive Maintenance is inadequate for NNI X & Y power supplies including shunt trip switches S1 and S2. (RI-152) 5.1.6 The NNI functional test may be inadequate to detect errors l
resulting from termination rework. (RI-154) 5.2 Open (Potential) Concerns I
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l 6.0 ATTACHMENTS j
6.1 List of Documents Reviewed 6.2 Status of RIs
- l 6.3 Detailed Observations - Requests for Information l
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LIST OF DOCUMENTS REVIEWED 1.
SSFIs A.
ANO B.
Oconee 1
C.
Palisades J
D.
Pilgrim E.
Rancho Seco I
F.
H.R. Robinson G.
Three Mile Island 1 H.
Trojan I.
Turkey Point i
2.
System Status Reports l
A.
Integrated Control System (Revisiort 1) 8.
Non-Nuclear Instrumentation (Revision 1) 3.
SMUD Vendor Technical Manuals A.
N21.01-115
)
8.
N21.01-116 I
C.
N21.01-117 I
D.
N21.01-112 1
E.
E32.09-IH01 (Automatic Buss Transfer Devices)
F.
M19.117-IM01 Signal Conversion Cabinet 4.
Drawings N15.07-55 Rev. 0 N15.07-57 Rev. 9 N15.07-58 Rev. 6 N15.07-59 Rev. 10 N15.07-60 Rev. 6 N15.07-61 Rev. 9 l
N15.07-62 Rev. 7 N15.07-63 Sht. 1, Rev. 7 Sht. 2, Rev. 1 N15.07-64 Rev. 10 l
N15.07-65 Rev. 4 N15.07-66 Rev. 3 l
i N15.07-69 Rev. 9 I
N15.07-70 Rev. 6 i
N15.07-74 Rev. 2 4
N15.07-75 Rev. 2 l
N15.07-76 Rev. 4 i
N15.07-77 Rev. 3 N15.07-79 Rev. 5 N15.07-80 Rev. 5 N15.07-81 Rev. 4
,l N21.01-67 Rev. 2 i
N21.01-68 Rev. 4 I
i N21.01-69 Rev. 5 l
N21.01-70 Rev. 3 ATTACHMENT 6.1 a
.b
LIST OF DOCUMENTS REVIEWED (Continued)
E307 Sht. 1 Rev. 32 E311 Sht. A DCN #8B for ECN A-5415-P E342 Sht. 4 Rev. 23 E342 Sht. 6 Rev. 22 M532 Sht. 2 Rev. 6 M532 Sht. 3 Rev. 6 E342 Sht. 17 Rev. 22 E342 Sht. 35 Rev. 21 E203 Sht 100 Rev. 3 E203 Sht. 101 Rev. 2 5.
Updated Safety Analysis Report, Chapter 7 (NNI) 6.
Nonconforming Reports A.
S-5302 B.
S-5381 C.
S-5386 D.
S-5429 E.
S-5466 F.
S-5468 G.
S-5486 H.
S-5487 I.
S-5543 J.
S-5546 K.
S-5710 7.
Quality Control Instrumentation 12 (QCI-12), Rev. 2 8.
Nuclear Engineering Procedures A.
NEP-5100, Series Construction Specs B.
NEP-4109, Configuration Controi, Rev. 6 C.
NEP-6118, Field Problem Reports, Rev. 3 D.
NEP-5447, NNI System Design Bases, Rev. 1 (Draft) 9.
NNI Testing Documents A.
System Test Matrix B.
STP.664, Rev. O C.
STP.lll5, Draft ATTACHMENT 6.1 (Continued) i LIST OF DOCUMENTS REVIENED (Continued) 10.
Procedures A.
Administrative Procedures (1) AP.26, Rev. 13 (2)
AP.23.0, Original (3) AP.33, Rev. 5 (4) AP.44, Plant Modification, Rev.11 (5) AP.100, Rev. 11 (6) AP.101, Rev. 39 i
(7)
AP.102, Rev. 9 j
(8)
AP.103, Rev. 12 1
(9)
AP.150, Rev. 14 l
(10) AP.151, Rev. 6 (11) AP.152, Rev. 10 (12) AP.153, Rev. 10 1
(13) AP.166, Rev. 11 (14) Emergency Plans B.
Rancho Seco Administrative Procedures
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(1)
RSAP.305 (2)
RSAP.601 (3)
RSAP.803 C.
Operating Procedures (1) A.73 (Reactor NNI)
(2)
B.2, Rev. 39 (Draft)
(3)
B.3, Rev. 29 (4)
B.4, Rev. 41 (Draft)
D.
Casualty Procedures (1) C.13A, Rev. 7 (2)
C.15, Rev. 11 (Draft)
(3)
C.172, Rev 0 (4)
C.173, Rev. 0 (5)
C.11, Rev. 2
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Modification Procedures and Inspection Standards 302 F.
Maintenance Administration Procedures MAP 009, Rev. O ATTACHMENT 6.1 (Continued)
LIST OF COCUMENTS REVIEWED (Continued) 11.
Engineering Changes (ECNs, DBRs)
EFIC A5415-P and DBR, Rev. 0
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R-0896, Rev. 1 and DBR, Rev. O R-0953, Rev. O and DBR, Rev. 1 A-4942, Rev. 2 and DBR, Rev. 1 R-0041, Rev. I and DBR, Rev. 2 R-0822, Rev. O R-0580, Rev O R-01255, Rev. O R-03598, Rev. 0 R-0861 R-0896 R-0927 R-0953 R-1106 R-1217, Rev. O R-0919 R-0825 12.
Field Problem Reports R-0861 FPR23 R-0896 FPR04,11 R-0927 FPR01,20,22,25,26 R-0953 FPB02 13.
PM Tasks for the NNI A.
Task 4146 B.
Task 5388 C.
Task 5390 D.
Task 5396 E.
Task 5397 F.
Task 5398 G.
Task 5399 H.
Task 5400 I.
Task 5607 J.
RPS Task 6772 l
14.
I&C Calibration Records for NNI 15.
Work Request History for NNI 16.
Quality Assurance Audit QA 87-024 17.
NRC Audit 86-41 1 l
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LIST OF DOCUMENTS REVIEWED (Continued)
I 18.
Operation Deficiency Report ODR 85-13 19.
B&W SPDS Functional Description (Draft) No. 1134042A9 20.
Fire Hazard Analysis ERPT-M0047, Rev. O Draft 21.
B&W Appendix R Evaluation 51-1152713-00 I
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ATTACHMENT 6.1 (Continued)
STATUS OF RIs.2 provides RI status as of this report date.
An RI is considered closed if the Team Leader was convinced a potential concern was not valid or not significant enough to be an RI.
An RI would also.be closed if requested information was provided.
All other RIs are open.
Acknowledged RIs are open RIs that bree been accepted as valid by the responsible organization and have been stated as concerns in Section 5.0.
RI NUMBER STATUS 129 Acknowledged 130 Closed 139 Acknowledged 142 Acknowledged 150 Acknowledged 152 Acknowledged 154 Acknowledged i
ATTACHMENT 6.2 '
__.___---_ __-_____ _ A
QETAILED OBSERVATIONS - REOUEST FOR INFORMATION During an evaluation, all potential concerns are documented on Request for Information sheets (RIs) that are sent to the responsible organization to receive their input concerning the potential concern.
RIs are also used to request information that the EASRTP team is having difficulty obtaining.
These RIs are considered draf ts throughout the entire evaluation until they become part of the report.
Responsible organizations can accept the potential concern as valid or they may disagree with the potential concern.
If they disagree, they can submit information that convinces the EASRTP team members that the potential concern is not valid, or they may redirect the EASRTP members to better focus the concern.
RIs developed during the system evaluation comprise this section of the report.
ATTACHMENT 6.3 a
REQUEST FOR INFORMATION (RI)
RI NO:
129 SYSTEM CODE:
NN1 ISSUE DATE:
08-13-87
SUBJECT:
NNI AUTOMATIC BUSS TRANSFER (ABT)
DEPARTHENT:
OPERATIONS COORDINATOR / EXT:
R. MACIAS/4589 TEAM LEADER / EXT:
R. M0YER/3850 POTE'NTIAL CONCERN /0UESTION:
The NNI 'X' and NNI 'Y' ABTs are designed such that a situation could exist where AC loads are lost while DC loads remain energized, which could cause difficulties in RCS makeup / letdown and seal injection control and damage to the makeup pump.
1)
A review of E-203, Sh. 101, Rev. 2, for NNI X and E-203, SH. 100, Rev. 3, shows both ABTs transfer from primary AC source to alternate AC source automatically, but cannot auto transfer from alternate to primary if alternate AC source is lost.
2)
An operator must depress the ABT's reset button to transfer back to that ABTs primary AC source.
3)
Plant could not provide a rationale justifying use of unidirectional versus bidirectional power seeking ABTs.
4)
ABT alignment to alternate AC source is annunciated on H2PSB.
Annunciator response procedure H2PSB window 23 (Rev. 16), step 5 states "when problem has been corrected then return to normal power supply by depressing reset pushbutton on the affected ABT device."
5)
Plant conditions may not allow immediate/near term alignment to i
primary AC power.
With the NNI 'X' ('Y') ABT aligned to the alternate, and with primary AC power available, a loss o' alternate AC power would deenergize all NNI 'X' ('Y') AC loads while all NNI
'X' ('Y') DC loads remain deenergized.
6)
Licensed Operators interviewed were aware the NNI ABTs are unidirectional power seeking and require resetting.
The operatcrs were not aware of the possibility that NNI
'X' ('Y') AC loads could be lost while NNI 'X' ('Y') DC loads remained energized.
7)
Failure modes and effects analysis report of ICS/NNI (2/16/87) states ICS will automatically trip on loss of NNI, thus tripping main feed pumps, closing Main Feedwater (HFH) block valves and
]
Although TBVs can be controlled manually and EFIC provides post trip, Atmospheric Dump Valve (ADV) and Auxiliary Feedwater (AFH) automatic control, operators may fail to take appropriate actions if it is not recognized that the failcro was caused by loss of NNI.
1 RI No:
123 (Continued) 8)
Report also discussed loss of automatic make-up and letdown control I
and loss of flash tank 3-way valve interlock.
If operators do not
+
recognize this condition of loss of NNI 'X' or 'Y' A/C power with DC
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still energized and appropriate action is not taken, a possibility of damage to the makeup pump /HPI pump exists, l
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REQUEST FOR INFORMATION (RI)
RI NO.
130 SYSTEM CODE:
NNI ISSUE DATE:
08-14-87
)
SUBJECT:
LOSS OF POWER TO SIGNAL CONVERSION CABINETS i
DEPARTMENT:
NUCLEAR ENGINEERING COORDINATOR / EXT:
R. LAWRENCE /3849 TEAM LEADER / EXT:
R. H0YER/3850 l
POTENTIAL CONCERN /00ESTION:
i During normal heatup and cooldown modes when EFIC initiation channels are in shutdown bypass, both Once Thru Steam Generators (OTSGs) could dryout upon loss of power to one signal conversion cabinet if the operator has selected 0TSGs startup range level instrumentation on the same channel.
This was not considered in the resolution of NNI System Status Report i
(SaR) problem #23 and could reduce plant reliability.
l NNI SSR Problem #23 resolution states, should the level in the OTSGs l
get below predetermined setpoint, EFIC will be initiated and would l
preclude dryout of bo'th OTSGs.
This resolution did not cover normal heatup and cooldown modes of the plant operation when EFIC l
initiation channels are in shutdown bypass mode.
EFIC initiation channels are in shutdown bypass mode during normal and heatup modes until certain plant conditions are achieved in accordance with operating procedures B.2, Rev. 39 draft, and B.4, l
Rev. 41 draft.
Prior to reaching a step in these procedures to enable or disable EFIC initiation channels, loss of power to one signal conversion cabinet could cause dryout of both OTSGs if the startup range level instrumentation for the OTSGs were selected on the same channel.
Upon loss of power, the indication will go mid-scale.
ICS will not provide feedwater to OTSGs since it
" believes" adequate level is maintained in the OTSGs.
Either of these operating procedures do not require the operators to select -different channels for OTSG's startup range level I
instrumentation.
l This RI closed.
Engineering response provided procedures which require operators to select different channels for OTSG's startup range level instrumentation upon loss of signal conversion cabinets. l
l REQUEST FOR INFORMATION (RI)
RI NO:
139 SYSTES CODE:
NNI ISSUE DATE:
08-17-87 1
I
SUBJECT:
ADEOUACY OF TESTING OF NNI Sis. 52s AND POWER SUPPLY DEPARTMENT:
SYSTEM ENGINEERING COORDINATOR / EXT:
JOHN ITTNER/4701 l
l TEAM LEADER / EXT:
R. M0YER/3850 l
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POTENTIAL CONCERN /0UESTION:
Testing of power supply capacity and Shunt Switches S1 and 52 coordination is not adequate.
Closing NNI X(Y) shunt switches individually may not result in NNI X(Y) DC power being energized.
1 ubleshooting Action Plans resulting from the investigation of the i
12/16/85 trip showed that ICS shunt switches and power supplies l
l installed as of 12/26/85 could not individually energize the ICS i
cabinet.
1 During discussion with system engireer he indicated that with new sh nt switches and power supplies, ICS can now power up on $1 and 52 i.dividually based on recent normal operation cycles.
Plant could not produce an STP or PP that tests the ability of $1 and $2 to individually power up NNI X(Y), though NNI SSR Problem No.
17 imolies_ a similar PM should be generated.
The ICS, NNI X(Y) arrangement of redundant power supplies and shunt I
si tches are very similar and actions and responses generally can be applied to all three.
Draft System Design Basis Report and ICS/NNI Manuals do not mention that the NNI X(Y) panels are required to be energized by closure of
$1 or S2 individually, however the panels are designed to continue operation on loss of one of the redundant power distributions.
It is important to determine if there is sufficient capacity and time delay present to allow energization on only one of the redundant power distributions.
Insufficient time delay and/or capacity could prevent the NNI from being repowered.
Depending on the plant condition, this could unnecessarily deprive the operators of instrumentation which would I
assist them in operating the plant.
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REQUEST r0R INFORMATION (RI) 1 RI NO:
142 SYSTEM CODE:
NNI ISSUE DATE:
08-17-87 l
1
SUBJECT:
OTSGs LEVEL INDICATIONS DEPARTMENT:
NUCLEAR ENGINEERING COORDINATOR / EXT:
R. LAWRENCE /4]f5_
l TEAM L EADER/ EXT:
R. M0YER/3850 1
POTENTIAL CONCERN /0UESTION:
Level indications for Once Thru Steam Generators (OTSGs) may cause operator confusion due to variations in ranges, engineering units, and l
displayed parameters (compensated vs. uncompensated level).
The level l
I indications vary on the Control Poom (CR) consoles, Boron Analyzer (BA) panel, Safety Parameter Display System (SPDS), Interim Data Acquisition Display System (IDADS), Remote Shutdown (RS) panel and Technical Support Center (TSC).
Currently the operators verify the operability of the Remote Shutdown panel by comparing OTSG's indications on the Boron Analyzer panel in the CR.
This would be difficult to do when uncompensated and compensated levels are being indicated on the BA panel and RS i
panel, respectively.
Examples of indication variations follow Full Range 600 inches of water l
Wide Range 619 inches of water Comp
- Temperature / Density compensated Uncomp
- Uncompensated i
Dep
- Dependent on HNI l
Ind
- Independent of NNI FULL /WLDE INDICATION l
Level Centrol Roca
- RS
- TSC :
- EFIC
- MIRI/ : BA SPDS
- IDADS
- Panel.
- Console : HlCO : Panel.
- Comp /Dep
- Uncomp/Dep :
x
- Comp /Ind x
- x/ wide : x/ wide :
x
- Uncomp/Ind :
x x
- x/ full : x/ full :
- x
- Range wide
- full : full
- wide
- full :
RI NO:
142 (Continued)
Startup Range (SR) 250 inches of water Narrow Range (NR) 156 inches of water STARTUP/ NARROW RANGE INDICATION Level Control Room
- RS
- TSC :
- EFIC
- HlRI/: BA SPDS
- IDADS
- Panel :
J
- Console : HlCO : Panel l
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- Comp /Dep
- Uncomp/Dep :
x
- Comp /Ind x
x/NR x/NR
- Uncomp/Ind :
x/SR x/SR l
Operating Range (OR) 100 %
Hide Range
= 6 - 619 inches of water OP.ERATING/ WIDE RANGE INDICATION Level Control Room
- RS
- TSC.
- EFIC
- HlRI/: BA SPDS
- IDADS
- Panel :
- Console : HlC0 : Panel :
- Comp /Dep x
- Uncomp/Dep :
- Comp /Ind x
- x/ wide;:
- x/OR
- Lt ~,mp/Ind :
x/OR OTSGs wide range (6-619") compensated level indications independent of NNI are indicated on the RS panel which have tag nos. as LI-20509 g
and LI-20510.
These indications receive an input from the transmitters LT-20507C and LT-20508C, respectively, per P&ID M-532, sh. 2 and 3 (issued for Information Only under Sub ECN A-5415P) whereas, these indicators receive an input from LT-20507A and LT-20508A, respectively, per 'he instrument loop diagrams I-54, sh. 17 and 24, part of Sub ECN A-5415P.
Currently the plant has transmitters LIT-20509 and LIT-20510 providing containment water level to SPDS, which may create confusion for the operators, since the OTSG indicator tag nos. are the same as these transmitters and imply they are from the same loop.
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RI NO:
142 (Continued)
Graphic displays are provided in SPDS for low-range pressure vs.
temperature (P-T), Abnormal Transient Operational Guidelines (ATOG) post trip P-T, and Inadequate Core Cooling P-T to display OTSGs startup range (0-250"' uncompensated level indications dependent on NNI; EFIC low (6-156") and hiah (6-619") compensated level indications independent of NNI.
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1 REQUEST FOR INFORMATION (RI) 1 RI NO:
150 SYSTEM CODE:
NNI ISSUE DATE:
08-17-87
SUBJECT:
INADEOUATE SETPOINT DOCUMENTATION DEPARTMENT:
NUCLEAR ENGINEERING COORDINATOR / EXT:
R. LAWRENCE /3849 TEAM LEADER / EXT:
R. M0YER/3850 i
POTENTIAL CONCERN /0UESTION:
1 1
Non-Nuclear Instrumentation (NNI) devices may be calibrated to incorrect setpoints.
NNI alarm and interlock setpoints are recorded in process standards by equipment ID short description and value (usually engineering units) and adjustment tolerance.
Process control and module settings are not recorded in process standaros.
Examples include proportional gains, function generator curves and limits.
I&C shop records do contain setpoints, process control and module adjustments.
These records are archived as permanent plant documents but not controlled.
Programmatic control of implementing new or modified setpoints is unclear.
Review of procedures for generation, implementation and turnover of modification packages (NEP-4109, RSAP-803, AP.44) revealed no direction for addressing setpoints.
There is no I
guidance on analyzing, documenting ard transmitting design setpoints and disseminating setpoints to setpoint documents and training.
Plant was unable to provide cross reference to, or assurance of i
existence of loop error an?. lysis for setpoints and/or indication, l
providing uncertainty in meeting USAR, Technical Specifications, regulatory and functional requirements for NNI and other plant systems.
Controlled documentation of module functions could not be provided.
i Maintenance and modifications require detailed knowledge of signal functions, and logic functions described in signal parameter, and j
engineering units.
Process standards is a partial setpoint document of selected l
instruments.
It does not reference support documents and does not provide signal to engineer unit conversions.
Plant could provide no criteria for instrument inclusion or exclusion in process standards. -
RI NO:
150 (Continued)
Plant could not produce error analysis on NNI instrument accuracy for instruments listed in the System Design Bases Report (SDBR).
Prccess standards provides adjustment tolerances.
Procedures such as I-038 series procedures provide as left and as found tolerances.
Without a controlled accessible document listing indication and loop accuracies, operations procedures may be requiring improper settings by not accounting for instrument errors.
The plant could not produce a controlled complete setpcint document (s) providing adequate information on setpoints, accuracies and supporting documentation.
Examples of conflicts between System Design Bases Report (SDBR) and Process Standards (PS), generally following DBR table 2, are as follows:
SBDR Value PS Value SlGLA1 l
160" AP101-16: 180" PZR LOW ALM No Entry AP101-10 pzr PORV 520 Deg F AP101-lSTEP 2:500 Deg F 4th RCP intlk No EQ-ID No tolerance 24" AP151-6: 20" SG low lvl AP102-3 MU tank Hi-lo aim Should be p3hl vs psh and psl I
i Reference DWG N15.07-77 25" AP102-3: 23" and 28" MU filter DP Hi AP102-4/5 FSH vs FSL HPI flow 3GPM AP102 Vary by RCP RCP seal inj flow l.4GPM AP!09-5 Vary by RCP RCP seal rtn flow Examples of conflicts between system DBR and process standards following the sequence of section 2 of the DBR are as follows:
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SBDR Value PS Value SIGNAL Bank 1,2,3,4 AP101-17 Bank A,B,C,D Pzr Htr banks 2140 psig 2140 psig Pzr Bank C off j
N15.06-64 2146 psig l
2255 psig AP101-17 2450 PORV 2205 psig AP101-17 2400 PORV 612 deg f AP101-8 610 deg F TH 520 deg f AP101-1 Step 1 500 Deg F Intik 4th RCP l
662 deg f AP101 AP166 No entry Pzr Temp ALM l
520 deg f AP101 AP166 No entry Pzr byp viv pos vs temp 310 deg f AP101 AP166 No entry Pzr safeties erb temp 2600 gpm AP103-3 2800 gpm DHS flow No entry AP101-10 500/450 PORV low sp AP166-8 G125 psia vs psig PST Turb Stm prs AP166-8 G107 psia vs psig RCP avg RC PRS
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REQUEST FOR INFORMATION (RI)
RI NO:
152 SYSTEM COD'd NNI ISSUE DATE:
08-18-87
SUBJECT:
ADEOUACY OF PREVENTIVE MAINTENANCE OF Nfl Sis. S2S AND POWER SUPPLY DEPARTMENT:
MAINTENANCE C00RDINATOR' XT:
J. DARKE/4727 TEAM LEADER / EXT:
R. M0YER/3850 POTENTIAL CONCERN /0UESTION:
Preventive Maintenance is inadequate for NNI X & Y power supplies including Shunt Switches Si and S2.
Not checking quality of power supply output could lead to lower reliability or loss of redundancy function.
Preventive Maintenance tasks do not check the quality of the NNI DC power supplies such as AC ripple.
In at least two previous insti.nces ICS/NNI power supply failures exhibited AC ripple as a symptom.
NNI SSR Problem 14 described one of these instances. Other instances were described in discussion with System Engineer.
NNI SSR Problem 17 discusses PM requirements and implies checking power supplies but not necessarily for quality of output.
Checking quality and not just quantity of output under load is necessary to increase reliability and avoid loss of redundant power supply function.
Preventive Maintenance does not address the shelf and useful life of shunt switches S1 and $2.
Currently it is possible to install a shunt switch near the end of manufacturer's guaranteed useful life and still following procedures, the NNI X (Y) would be put in service for up to five years with Shunt Switch (es) that are not guaranteed to operate within the design parameters.
As with the ICS, this could cause unnecessary sensitivity to minor voltage variations that otherwise do not affect system operation.
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l REQUEST FOR INFORMATION (RI)
RI NO:
154 SYSTEM CODE:
NNI ISSUE DATE:
08-18-87
SUBJECT:
TESTING OF RELUGGING AND WIREWRAPPING REWORK IN NNI DEPARTMENT:
SYSTEMS ENGINEERING COORDINATOR / EXT:
J. ITTNER/4153 TEAM LEADER / EXT:
R. H0YER/3850 POTENTIAL CONCERN /0UESTION The NNI Functional Test (STP.lll5) may be inadequate to detect all the errors that could result from all the relugging and wirewrapping that was done in the NNI system; errors which could lead to a plant trip or to making a plant trip more complex.
Due to an identified cause of the December 26, 1985 trip, a bad lug in the ICS, a significant number (thousands) of terminations and wirewrap connections in the ICS and NNI were inspected and I
reworked.
(ICS SSR problem #10, NNI SSR problem 13)
Quality control inspection was requested and performed on the quality of the terminations only.
Recent findings (NCRs) S-6603, S-6867 indicate some terminations were not returned to their proper location in the ICS system.
Due to the similarity of work done in the NNI system with relugging and wirewrapping, there is no guarantee that all of these wires have been returned to their proper places.
The NNI Function Test (STP.1115) is presently in draft form only and unavailable for comprehensive review.
However, due to its similarity in content with ICS, the NNI functional test may not contain the necessary steps to detect all the errors resulting from re-terminations, as was found in review of the ICS system functional test.
(RI-080) l l l
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