ML20245D415
| ML20245D415 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 05/23/1988 |
| From: | Bailey J WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| ET-88-0076, ET-88-76, NUDOCS 8805310093 | |
| Download: ML20245D415 (9) | |
Text
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WQLF CREEK
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NUCLEAR OPERATING CORPORATION John A. Bahy Vke Preedent May 23,1988 ET 88-0076 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555
Reference:
Letter dated April 8,1988 from L. J. Callan, NRC, to B. D. Withers, WCNOC
Subject:
Docket No. 50-482 :
Response to Notice of Violation 482/8724-01, 02, 03 and 04.
Gentlemen:
Attached is a detailed response to violations 482/8724-01, 02, 03 and 04 which are documented in the Reference.
The violation's concern equipment qualification documentation files which did not establish that this equipment was qualified.
If you have any questions concerning this matter, please contact me or Mr. O. L. Maynard of my staf f.
Very truly yours, John A. Bailey Vice President Engineering & Technical Services l
JAB /jad Attachment cc B. L. Battlett (NRC), w/a l
D. D. Chamberlah (NRC). v/a l
R. D. Mars in (NRC), w/a P. V G'Coanor (IE ), w/a (2) l k
88C' PDR O
Av 411 < tunnyn, AS 66839 / Phone. (316) 364-8831 k
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4 Attachment to ET 88-0076 Page 1 of 8 Violation (482/8724-01):
Finding _A:
Paragraph ( f) of 10 CFR 50.49 requires that qualification of each component must be based on testing or experience with identical equipment, or with aimilar equipment with a supporting analysis, to show that the equipment to be qualified is acceptable.
Paragraph (k) of 10 CFR 50.49 states that equipment previously required by the Commission to be qualified to NUREG-0588 (For Comment version), "Interim Staff Position on Environmental Qualification of Sa fe t y-Relat ed Electrical Equipment," need not be requalified.
Paragraph 5(1) of NUREG-0588 states that the qualification documentation shall verify that each type of electrical equipment is qualified for its application and meets its specified performance requirements.
The basis of qualification shall be explained to show the relationship of all facets of praof needed to support adequacy of the complete equipment.
Data used to demonstrate the qualification of the equipment shall be pertinent to the application and organized in an auditable form.
Contrary to paragraphs (f) and (k) of 10 CFR 50.49, and Section 5(1) of NUREG-0588, Category I, Wolf Creek Nuclear Operating Corporation (WCNOC) did not adequately support qualification of Raychem installed splice configurations or establish similarity between tested and installed spilces.
The equipment qualification file (EQF) EQWP-01013 for Raychem cable termination material did not establish qualification for (1) installed splice seal lengths under 2 inches; (2) splices with no adhesive protruding from the heatshrink tubing ends; and (3) splices with bend radi significantly less than 5 times the outside diameter, in applications of EQ sa fety-related equipment (Appendix B, paragraphs 4.f(1), 4.g(l),
4.g( l )( e),
4.h(1)(c), 4.h(1)(b), and 4.h(1)(c)).
Reason for Violation:
The reason for this violation was that procedures / work instructions for installing Raychem splices during construction of the Wolf Creek Generating Station (WCCS) did not provide the necessary detail to assure strict compliance with all of the design and manufacturer's requirements and recommendations. Therefore, in some cases, the final installation did not comply with all the Raychem requirements.
The Raychem Splice Environmental Qualification documentation on file at Wolf Creek did not address deviations from the design and manuf acturer's requirements.
Therefore, the Environmental Qualification of the splices in their as found condition was not supported by the existing qualification package as required by 10 CFR 50.49.
a Attachment to ET 88-0076 Page 2 of 8 Corrective __ Steps Which Have Been Taken__And Results Achieved:
As a result of the NRC and utility identified concerns, an inspection of splices on instrumentation and control circuits was conducted.
This inspection identified numerous instrumentation circuit splices that failed the inspection criteria which resulted in a rework of the harsh environment NUREG-0588 Appendix E Category A and B instrumentation circuit splices and a small number of control circuit splices.
Instrument and Control (I&C) procedure INC-S-506 "Wire Splicing and Te rmina t ion With Raychem" was revised to include detailed work instructions for installation of Raychem splices. This revised procedure was used by I&C personnel in the rework of the instrumentation circuit splices. Maintenance personnel reworked the affected control circuits using detailed instructions included with the work request.
Personnel involved in this rework were trained on the installation of these splices.
Wolf Creek Nuclear Operating Corporation (WCNOC) subsequently obtained an environmental qualification report developed by Wyle Labs which adequately demonstrates qualification for splices at WCGS.
This documentation addresses Raychem splices with seal lengths, bolt sizes, substrate material and bend radii which do not comply with the design criteria.
Equipment Qualification Work Package (EQWP) E-01013 was revised to reflect the test report results.
Corrective __ Steps _)hich Will Be Taken To Avoid Further Violations:
An additional procedure will be implemented by the Maintenance organization providing detailed instructions for installation of Raychem splices.
Until this procedure is issued, Maintenance will include detailed instructions with the work request for work involving Raychem splices.
Date When Full _ Compliance Will Be Achieved:
EQWP E-01013 was revised on December 29, 1987.
The Maintenance procedure will be implemented by June 15, 1988.
Violation (482/8724-02):
Finding _B:
Paragraph ( f) of 10 CFR 50.49 requires that qualification of each component must be based on testing or experience with identical equipment, or with similar equipment with a supporting analysis, to show that the equipment to be qualified is acceptable.
4 Attachment to ET 88-0076 Page 3 of 8 Paragraph (k) of 10 CFR 50.49 stated that equipment previously required by the Commission to be qualified to NUREG-0588 (For Comment version), "Interim Staff Position on Environmental Qualification of Sa fe t y-Relat ed Electrical Equipment," need not be requalified.
Paragraph 2.2(5) of NUREG-0588 states that equipment should be located above flood level or protected against submergence by locating the equipment in qualified watertight enclosures.
Where equipment is located in watertight enclosures, qualification by test or analysis should be used to demonstrate the adequacy of such protection.
Where equipment could be submerged it should be identified and demonstrated to be qualified by test for the duration required.
Contrary to paragraphs ( f) and (k) of 10 CFR 50.49, and Section 2.2(5) of NUREG-0588, Category I, the EQF for Minco Models S8809 and S8810 resistance temperature de tectors ( RTDs),
located in the containment, did not support qualification for submergency for the RTD cable termination seals, housed in terminal boxes below the flood level ( Appendix B, paragraph 4.h(2)).
Reason for Violation:
The splices for the Minco RTDs are located in t e rmi na l boxes TB23209,
- TB23210, TB23211 and TB23212.
While TB23209 and TB23212 are located entirely above flood level, the bottom of TB23210 and TB23211 were located 12" below the maximum postulated flood level for WCGS.
It appears that this configuration was not accounted for in the EQ reviews which were conducted as part of the design process.
A review of the applicable design drawings and qualification documentation has shown this design error to be an isolated case.
i Corrective St_e,ps Which Have_Been Taken And Results Achieved i
To obtain compliance with the existing qualification report for the MINCO RTDs, terminal boxes TB23210 and TB23211 were relocated above flood level by Plant Modification Request 02319.
WCNOC has reviewed design drawings for all NUREG 0588 Appendix E Category A and B equipment located inside l
containment and has determined that all equipment (including terminations) l is either:
1) located above the maximum postulated flood level for WCGS or 2) the equipment has been qualified for submerged operation or 3) submerged operation of the equipment is not required and submergence of the equipment would not affect the operability of other sa fety related equipment.
Additionally, WCNOC has performed an analysis which demonstrates j
the qualification of the MINCO RTD's for submerged application.
I l
s reachment to ET 88-0076 Page 4 of 8 Corrective St_eys Which Will Be Taken To Avoid Further Violations:
Since this was detemined to be an isolated case, no additional corrective steps are required.
It should be noted that the plant modification process requires the ef fects of the design change on the qualification of equipment (which includes the effects of flooding) to be considered.
In addition, flooding is addressed in the 10CFR50.59 safety evaluation performed for safety related plant modifications.
Date When Full Comgliance Will Be Achieved:
Full compliance was achieved on November 7, 1987 when terminal boxes TB23210 and TB23211 were relocated above flood level.
Violation (482/8724-03):
Finding _C:
Paragraph ( f) of 10 CFR 50.49 requires that qualification of each component must be based on testing or experience with identical equipment, or with similar equipment with a supporting analysis, to show that the equipment to a
be qualified is acceptable.
Paragraph (k) of 10 CFR 50.49 states that equipment previously required by the Commission to be qualified to NUREG-0588 (For Comment version), "Interim Staf f Position on Environmental Qualification of Safety-Related Electrical Equipment," need not be qualified.
Paragraph 5(1) of NUREG-0 588 states that the qualification documentation shall verify that each type of electrical equipment is qualified for its application and meets its specified performance requirements.
The basis of qualification shall be explained to show the relationship of all facets of proof needed to support adequacy of the complete equipment.
Data used to demonstrate the qualification of the equipment shall be pertinent to the application and organized in auditable f o rm.
Contrary to paragraphs ( f) and (k) of 10 CFR 50.49 and Section 5(1) of NUREC-0588, Category I, the EQF for Limitorque motor operators, Series SMB (EQFs HE-1, HE-4, and BOP-Limitorque),
did not adequately support qualification because of a failure to analyze adequately all possible effects of energized space heaters used within the motor operator assembly.
The analyses contained in the EQFs did not fully establish qualification for failure modes other than an open circuit.
Air temperature rises resulting from the proximity of cables, wires, splices, and components to heaters were not analyzed.
The test report used for qualification of heaters was determined to be inadequate ( Appendix B, paragraphs 4. f(2)( a),
- 4. f( 2)( b),
- 4. f( 2 )( c), and 4.g(4).
Attachment to ET 88-0076 Page 5 of 8 Reason for Violation:
Prior to the NRC Inspection, WCNOC Engineering had evaluated the potential adverse ef fects of energized heaters and, based upon a review of the design and upon results of a recent extensive inspection and wiring replacement effort, determined that the Limitorque operators were qualified with the heaters installed and energized.
Some failure modes were deamed highly unlikely based on the design and construction of the heaters and were not included in this evaluation.
Since the heaters were being removed as time and plant conditions allowed, Engineering used a combination of analysis and operating experience as allowed by 10 CFR 50.49 to support qualification.
Corrective Steps Which Have_Been__Taken And Results_ Achieved:
WCNOC submitted in Reference 1 a Justification for Continued Operation for Limitorque operators outside containment with limit switch compartment space heaters energized.
Limit switch compartment space heaters in Limitorque operators located inside containment (plus 35 Limitorque operators located outside containment) were removed during the second refueling outage.
WCNOC believes that the referenced tests included in Appendix A of Reference 1, while not performed in strict conformance to current industry standards, demonstrate the inherent ruggedness of the space heaters and provide reasonable assurance that a common mode failure of the heaters would not happen.
Regarding the ef fects of energized heaters on components in close proximity to such, one wire examined during the EQ inspection (which was disconnected from the circuit) had signs of insulation damage caused by overheating.
It is WCNOC's judgement that no other wires (or other components) at WCCS suffered damage that could be attributed to overheating.
During a massive rewiring of Limitorque operators in June 1986, in which more than 4000 wires were replaced ( for reasons other than degraded insulation),
no degradation of wire insulation due to overheating was evident.
These wires are maintained at WCCS and were examined by the NRC during the EQ inspection.
WCNOC has conducted an analysis using temperature measurements taken in the proximity of an energized space heater for a typical Limitorque operator.
The analysis concludes that the qualified life for Limitorque limit switch compartment components, when accounting for the period of space heater energization, remains greater than 40 years.
Attachment to ET 88-0076 Page 6 of 8 Corrective _Steys Which Will Be Take_n To Avo_id Further Violations:
The remaining Limitorque switch compartment space heaters will be removed in conjunction with scheduled maintenance on valves throughout Cycle 3.
All Limitorque switch compartment space heaters will be removed prior to startup from the next refueling outage.
The Limitorque EQWP's have been revised to reflect the configuration of Limitorque operators without the compartment space heaters.
The analysis regarding the ef fects of energized heaters on Limitorque components will be incorporated into the qualification documentation for Limitorque operators.
Date When Full _Comgliance_Will Be A_cnieved:
All Limitorque limit switch compartment space heaters will be removed prior to startup from the next refueling outage.
The additional analysis will be incorporated into the relevant Limitorque EQWP's by May 31, 1988.
Violation (482/8724-04):
Finding,D Paragraph ( f) of 10 CFR 50.49 requires that qualification of each component must be based on testing or experience with identical equipment, or with similar equipment with a supporting analysis, to show that the equipment to be qualified is acceptable.
paragraph (k) of 10 CFR 50.49 states that equipment previously required by the Commission to be qualified to NUREG-0588 (For Comment version), "Interim l
Staff Position on Environmental Qualification of Safety-Related Electrical j
Equipment," need not be requalified.
Paragraph 5(1) of NUREG-0588 states that the qualification documentation shall verify that each type of electrical equipment is qualified for its application and meets its specified performance requirements.
The basis of qualification shall be explained to show the relationship of all facets of proof needed to support adequacy of the complete equipment.
Data used to demonstrate the qualification of the equipment shall be pertinent to the application and organized in an auditable form.
Contrary to paragraphs ( f) and (k) of 10 CFR 50.49 and section 5(1) of NUREG-0588, Category I, the EQF for Marathon terminal blocks, Model 1600, did not adequately establish qualification because of a failure to demonstrate that these components can perform their required function for all postulated service conditions.
The EQF E-028 test reports indicated that unacceptably high leakage currents may occur during electrical bus energization ( Appendix B, paragraph 4.f(8)(b)).
4 Attachment to ET 88-0076 Page 7 of 8 Reason for Viol _ation:
WCNOC does not believe that failure to clearly address the test anomaly identified in the finding constitutes a violation of 10 CFR 50 49 due to the following reasons.
The leakage currents re ferred to are discussed in Wyle T'.4t Report 45603-1, wherein 6 terminal blocks (of which 4 are not used at WCGS) were ivired in a serpentine manner with a 12 ampere fuse in the ground path. During the LOCA testing, af ter a loss of and upon restoration of power, it was discovered that the fuse in the leakage current path had blown.
Because of the wiring arrangement used, from which it is not possible to determine the source of the leakage current, and because leakage current readings were not taken during the LOCA phase, this test leaves the qualification status of the Harathon 1600 terminal blocks indeterminate. WCNOC did not use this test as the basis for qualification of these terminal blocks. WCNOC did not address the subject fuse failure in the qualification documentation for the Marathon 1600 terminal blocks for two reasons:
1) it is not clear from either NUREG-0588 lEEE 323-74 or 10CFR50.49 that anomalies that occur in testing which is not relevant to WCCS need be addressed (i.e.
[f the anomaly had been analyzed, the analysis would have been meaningless, since the LOCA portion of the test was not performed in an acceptable manner) and 2) additional LOCA testing performed on the identical terminal blocks used in the subject test (summarized in Wyle Test Report 17657, which is included as Reference ( C) of EQWP E-028) adequately demonstrated qualification of Marathon 1600 terminal blocks for use at WCCS.
Although these arguements were presented during the inspection period, they may not have been communicated clearly enough.
Additionally, contrary to the statements made in Inspection Report 87-24, page 24, paragraph ( 8)( a),
(which states that the circuits were always energized during the testing in test report 17657),
and paragraph ( 8)( b),
(which states that the testing at constant power is not the worst case), the tested circuits in test report 17657 were not continuously energized.
Circuit switches were opened and closed successfully during the LOCA simulation.
This is discussed in detail in Reference 1, page 9 of 89.
Therefore, the fuse failures that are discussed in Wyle Report 45603-1 were due to the wiring configuration (which is not representative of the WCGS configuration) and not due solely to the interruption of power.
C_orrective S_t_e_ps 3 ich Have Been Taken And Results_ Achieved:
Although WCNOC believes the qualification documentation for Marathon 1600 terminal blocks was acceptable at the time of the NRC EQ inspection, a
review and analysis which provides clarification of the fuse blowing anomaly was pe r f o rmed.
The clarification has been incorporated into EQWP E-028.
Re ference 1 submitted this analysis.
Attachment to ET 88-0076 Page 8 of 8 Corrective S_teys_Vhich Will Be Taken_T_o_ Avoid Further Violations:
I The steps taken above will avoid further violation concerns in this area.
Da_te_When Full Comgliance Will_Be Achie_ve,d_:
Full compliance existed at the time of the inspection.
Clarification to EQWP E-028 was provided on November 28, 1987.
References:
1.
Letter ro. WM 87-0309 dated November 20,1987 from B. 9. Withers, WCNOC to R. D. Martin, NRC i
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