ML20214J083
| ML20214J083 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 11/13/1986 |
| From: | Gardner G, Murphy M, Stewart D TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20214H850 | List:
|
| References | |
| 303.03-SQN, 303.03-SQN-R03, 303.03-SQN-R3, NUDOCS 8612010145 | |
| Download: ML20214J083 (8) | |
Text
r TV3 EMPLOYEE ODNCERNS REPORT NUICER: 303.03-SQN SPECIAL PROGRAM REPORT TYPE: Sequoyah Nuclear Plant - Element REVISION NUMBER: 3 TITLE: Accuracy of Safety-Related Instruments REASON FOR REVISION:
Revised to incorporate SRP Comments and Corrective Action Response. Revision 1 Revised to incorporate SQN Corrective Action Response. Revision 2 Revised to incorporate SRP comments for final report. Revision 3 PREPARATION PREPARED BY:
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MSRP Secretary signature denotes SRP concurrence are in files.
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B612010145 861117 PDR ADOCK 05000327 P PDR l
l TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT ENPLOYEE CONCERNS TASK GROUP OPERATIONS CEG l
Subcategory: Instrumentation and Radiation Nonitoring Element: Accuracy of Safety-Related Instruments Report Number: 303.03 SQN, Revision 3 IN-85-802-001 IN-86-079-002 Evaluator: [.$nual) in,0m Il-ID -86 G. D. Ga dne Date Reviewed by: ' OPS'CEG
/// //-/S"/4 aber Date Approved by: hei -
m a lI-IO-5(4 W. R. Lage)gfen Date 1311T
Rsvision 3 I. Accuracy of. Safety-Related Instrumentation This report evaluates issues regarding Target Rock valve reed l switches and accuracy of radiation monitors at Sequoyah Nuclear IRI Plant - (SQN). These concerns were determined to be potentially cafety-related by the Employee Concerns Task Group (ECTG), Technical Assistance Staff (TAS).
II. Specific Evaluation Methodology The following issues were identified by Quality Technology Company (QTC) l for Watts Bar Nuclear Plant: lR1 h IN-85-802-001 Both units 1 and 2, problem exists with Target Rock valves installed on both Sampling System and Main Steam system. Target Rock valves improperly annunciate part of the time and reed switches on valve require constant adjustment. Valves in Sampling System located in H 3/8-inch stainless steel lines in Annulus and Primary Containment areas. Valves in Main Steam System located on either 2-inch or 3-inch stainless steel lines in South valve room. CI did not
- . specify the line numbers or valve serial or mark numbers.
L IN-86-079-002 s
Questionable adequacy of safety-related equlpment accuracy and questionable calibration procedures for this equipment. Details s known to Quality Technology Company (QTC), withheld due to confi-y dentiality. Nuclear Power (NUC PR) concern, units 1 and 2 system j withheld, timeframe - current. Concerned Individual (CI) has no further information.
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li The issues above were evaluated by the SQN Generic Concerns j Task Force (GCTF) (References 1 and 2) for applicability to SQN. These reports were reviewed for adequacy.
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h III. Findings IN-85-802-001 i
I The GCTF report for this issue determined that Target Rock valves were lR3
) used as containment isolation valves for post accident sampling
] (System 43) and containment differential pressure (System 30),and on the l} reactor head vent (System 68, Reactor Coolant System). The valves in IR1 l} Systems 43 and 30 use the position switches as a seal-in contact in the l valve opening circuit. The position switches are used for the lR3 L indicating circuit on system 68 valves.
l The GCTF report identified no safety-related deficiencies that could r result from a malfunction or misadjusted position switch.
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Ravision 3 Section III.E of the GCTF report is unclear on which valves were I researched for equipment qualification and maintenance history. l According to the GCTF evaluators, the Target Rock valves which IR1 replaced the former air operated pressurizer relief valves are the l ones being discussed in that section. I The report indicated that maintenance personnel were aware of proper adjustment procedures as recommended by the vendor, however, no documented instruction exists. The report recommended that a maintenance instruction be issued to provide adjustment instruction for Target Rock valves. This recommendation was not considered a safety issue by the GCTF but rather an enchancement. lR3 IN-86-079-002 The GCTF report for this concern obtained follow-up information from QTC which indicated that the concerned individual believed radiation monitoring equipment to be only 30 percent accurate, i.e., 70 percent lR1 in error. An Instrument Naintenance foreman interviewed during the GCTF evaluation noted that certain Gulf Atomic liquid process monitors have a tolerance of -10 to +35 percent counts per minute (CPN) with the
+35 percent being in the conservative direction. The report stated that alarm set points are governed by the Technical Specifications, however, the surveillance test procedures require the actual set point to be below the plant limiting conditions. The report also noted that should an alarm be activated, backup methods are used to determine the extent of the problem which include special sampling or increased sampling frequencies by the Radio Chem lab and Health Physics.
Cognizant personnel (Supervisor, lead engineer) in the Division of l Nuclear Engineering Radiation Protection Section, contacted during the l WBN evaluation for this concern, stated that the CI may have observed an I unusual circumstance. The DNE personnel noted that shielding and lR1 distance from source to monitor directly affects the radiation level l measured by a monitor and could result in a 70 percent lower reading I compared to another instrument nearer the source. The DNE personnel IR3 also suggested the CI may have observed a monitor which was inoperable. l Because of the lack of information specified in the concern, it is not lR1 possible to fully address the observations of the CI. l Although this issue identled for WBN, the SQN Instrument Maintenance l Instruction (INI) for radiation monitor calibration (reference 3) was l reviewed for adequacy. No problems were noted with the calibration lR3 procedure. l The GCTF report concluded that although design and test data reviewed l and personnel interviewed did not negate the employee concern as stated. l the radiation monitoring equipment at SQN meets intent of the design IR3 and surveillance testing requirements for the types of conditions l considered in selecting it for SQN. l Page 2 of 5
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Ravision 3 Conclusion
- 1. The issue presented by IN-85-802-001 was not validated for SQN based on the evaluation performed by the GCTF. The maintenance history reviewed during the GCTF evaluation did not indicate a l recurring drift problem at SQN. No safety-related deficiencies IR1 were identified, however, recommendations were made to provide written instructions for adjustment of Target Rock valve position
- switches.
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- 2. The issue presented by IN-86-079-002 was not valid for SQN based l: on the GCTF report, a review of the calibration procedure, and IR3 L discussions with DHL during the WBN evaluation. Some monitors l L have a +35 percent tolerance; however, these tolerances are con- lR1 L servative and alarm set points are selected below the limiting conditions for operation specified in the technical specifications.
No procedural deficiencies were identified by this evaluation and lR3 no employee safety risks would be incurred by continued use of the 1 equipment.
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, IV. Perceived Root Cause I
1 No specific deficiencies were identified by this evaluation. The need I i for a procedure to adjust reed switches should be based on the l
? difficulty of the work activity and general knowledge of the craftsman. lR3 The lack of a maintenance procedure for adjusting Target Rock valve l reed switches is therefore, not considered a deficiency. A root I cause evaluation is not required. l Y. Generic Applicability J
l Evaluations completed for SQN and BFN on IN-85-802-001 resulted in no l L negative findings. The recurring drift problem appears to be isolated IR1 at WBN and therefore the issue is not considered generically applicable I to BLN. I Employee concern IN-86-079-002 has been evaluated for SQN and WBN with no negative findings and therefore, is not considered generically applicable 1 to any other plant.
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Rsvisien 3 VI. References
- 1. SQN Generic Concerns Task Force Report on employee concern IN-85-802-001, " Problems with Target Rock Valves," Revision 1, June 13, 1986
- 2. SQN GCTF Report on employee concern IN-86-079-002, " Questionable Accuracy and Calibration Procedures for Radiation Equipment,"
Revision 1 June 13, 1986 lR1
- 3. SQN iMI-90, Revision 6. " Radiation Monitoring System," l September 27, 1984 lR3 t
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t-Rsvision 3 VII. Immediate or Long-Term Corrective Action IN-85-802-001 1 l
A procedure will be developed to provide instructions for the adjustment I of Target Rock Valve position switches. The procedure will be complete l by February 1, 1987. This corrective action will be performed by SQN l Electrical Maintenance and tracked by NATs 9240. l l
IN-86-079-002 lR2 l
Although no corrective action was required by this evalution, the SQN l response to this report stated that in order to provide for additional l assurance that the radiation monitor calibration procedures are techni- l cally adequate, these procedures are being reviewed using the SI check- l l
list for guidance. This activity will be completed before plant startup i
' and will be tracked at SQN by P2 activity 200011950. This is part of l j an overall program at SQN to review sis for adequacy. l l
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1 1:LTEREHCE - ECPS120J-ECPS121C TENNESSEE VALLEY AUTHORITY PAGE -
195 1 IREQUENCY - REQUEST OFFICE OF MUCLEAR PONER RUN TIME - 11:47:B)
ONP - ISSS - RUlf EMPLOYEE CONCERN PROGRAM SYSTEM (ECPS) RUN DATE - 10/21/87 LIST OF EMPLOYEE CONCERN INFORMATION i
.ATEGORY: OP PLANT OPER. SUPPORT SUBCATEGORY: 30303 ACCURACY OF SAFETY-RELATED-INSTRUMFMTATION f r
S GENERIC - KEYNORD A G H APPL QTC/NSRS P KEYWORD B COHCERN SUB R PLT BBSH INVESTIGATION S CONCERN KEYHORD C f NUf1BER CAT CAT D LOC FL4B REPORT R DESCRIPTION KEYNORD D f IN 802-001 DP 30303 N HBN YNYY I-85-286-H5N -BOTN UNITS 1 & 2, PROBLEM EXISTS HIT DESIGN REVIEW k T50071 REFORT H TARGET ROCK VALVES INSTALLED IN B0 PROCUREMENT g TH SAMPLING SYSTEM AND MAIN STEAM SY PIPING -
STEM. TARGET ROCK VALVES IMPROPERLY VALVES $
ANNUCIATE PART OF THE TIME AND READ SHITCHES ON VALVES REQUIRE CONSTANT I ADJUSTMENT. VALVES IN SAMPLING SYS TEM LOCATED IN 3/8" STAINLESS STEEL
. LINES IN ANNULUS AND PRIMARY CONTAIN i MENT AREAS. VALVES IN MAIN STEAM SY STEM LOCATED ON EITHER 2" OR 3" STAI NLESS STEEL LINES IN SOUTH VALVE R00 i M. C/I DID NOT SPECIFY LINE NUMBERS I 6
OR VALVE SERIAL OR MARK NUMBERS IN 079-002 OP 30303 N HBN NNYY NS QUESTIONABLE ADEQUACY OF SAFETY RELA NONCONFORMANCE g 750117 K-FORM TED EQUIPMENT ACCURACY, AND QUESTION CALIBRATION ABLE CALIBRATION PROCEDURES FOR THIS CONSTRUCTION j j
EQUIPMENT. DETAILS KNOWN TO QTC, H EQUIPMENT j ITHELD DUE TO CONFIDENTIALITY. NUCL EAR POWER CONCERN; UNITS I & 23 SYST i
EM HITHELD; TIME FRAME - CURRENT. C
- I HAS NO FURTHER INFORMATION NO FOLL l DMUP REQUIRED.
2 CONCERNS FOR CATEGORY OP SUBCATEGORY 30303 1
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