ML20207L222
| ML20207L222 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/30/1986 |
| From: | Russell J TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20207K584 | List: |
| References | |
| 223.2(B), 223.2(B)-R, 223.2(B)-R00, NUDOCS 8701120032 | |
| Download: ML20207L222 (10) | |
Text
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. TVA EMPLOYEE CONCERNS REPORT NUMBER: 223.2(B)
SPECIAL PROGRAM REPORT TYPE: SEQUOYAH ELEMENT REVISION NUMBER: 0 TITLE: INSTRUMENT SUPPORT DESIGN Instrument Mounting Brackets PAGE 1 0F 9 REASON FOR REVISION:
1 PREPARATION
. PREPARED BY:
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REPORT NUMBER: 223.2(B)
TVA EMPLOYEE CONCERNS SPECIAL PROGRAM REVISION NUMBER: 0
( PAGE 2 0F 9
- 1. CHARACTERIZATION OF ISSUES:
Concern: Issues:
IN-85-973-002 a. Instrument mounting brackets are not
" Typical instrument mounting strong enough to support instru-brackets consisting of thin ments.
gauge, perforated sheetmetal (or similar material) are not b. In heavy traffic areas, the brackets strong enough to support the are susceptible to abusive treatment instruments (generic for typical which causes damage to brackets and mounts). Constant bumping into, instruments.
leaning against, and sitting on these brackets / instr. causes c. All such installations should be damage to both brackets and redesigned.
instruments. CI could not provide specific instrument nLmbers, locations, etc., but stated all such installations The following issue from this should be subject to re-design. concern is addressed in another This was reported to manager report:
(j (known) but no action was taken."
This deficiency was reported to manager but no action was taken (addressed by Nanagement Group in Sequoyah Element Report 706.01).
- 2. HAVE ISSUES BEEN IDENTIFIED IN ANOTHER SYSTEMATIC ANALYSIS? YES X NO
[
Identified by Gilbert / Commonwealth (G/C) and TVA Date 03/03/86 and 06/04/86 Documentation Identifiers:
G/C Report No. 2614 and TVA - Generic Concern Task Force (GCTF) l Report for Concern No. IN-85-463-006.
l
! 3. DOCUMENT NOS., TAG NOS., LOCATIONS OR OTHER SPECIFIC OESCRIPTIVL l IDENTIFICATIONS STATED IN ELEMENT:
The concern addressed instrument mounting brackets in general.
l I C 0574D - 12/05/86
TVA EMPLOYEE CONCERNS REPORT NUMBER: 223.2(B)
SPECIAL PROGRAM REVISION NUMBER: 0 PAGE 3 0F 9
- 4. INTERVIEW FILES REVIEWED:
The working and expurgated inte'. view files for concern IN-85-973-002 were reviewed. The expurgated file contains only the K-form and the working file does not have any other new item
( App. A, 7.a) .
- 5. DOCUMENTS REVIEWED RELATED TO THE ELEMENT:
See Appendix A.
- 6. WHAT REGULATIONS, LICENSING COMMITMENTS, DESIGN REQUIREMENTS OR OTHER APPLY OR CONTROL IN THIS AREA?
See Appendix A.
- 7. LIST REQUESTS FOR INFORMATION, MEETINGS, TELEPHONE CALLS, AND OTHER DISCUSSIONS RELATED TO ELEMENT.
(h,:1l See Appendix A.
- 8. EVALUATION PROCESS:
- a. Reviewed FSAR and SQN aesign criteria for TVA's commitments to operating and seismic design requirements for Category I instrument supports.
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- b. Obtained and reviewed TVA drawing series 47W600 which shows j
l instrument mounting brackets.
- c. Reviewed various revisions of applicable drawings for i
evidence of changes in engineering design requirements.
- d. Reviewed seismic qualification test data, which support design, and performed calculations, as needed, b.
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r REPORT NUMBER: 223.2(B)
. TVA EMPLOYEE CONCERNS SPECIAL PROGRAM REVISION NUMBER: 0
[ PAGE 4 0F 9
- 9. DISCUSSION, FINDINGS, AND CONCLUSIONS:
Chronology:
07/31/85: Concern submitted to TVA 03/03/86: G/C reported deficiency in fasteners of instrument mounting brackets 06/04/86: TVA GCTF recommenced walkdowns to verify adequacy of safety-related instrument installations Discussion:
FSAR Section 3.10, " Seismic Design of Category I Instrumentation and Electrical Equipment," identifies TVA's commitment to provide instruments which are capable of performing their functions during .
and following a safe shutdown earthquake. Instruments are classified as Seismic Category I in accordance with the systems and '
their functions. Furthermore, SQN design criteria SQN-DC-V-10.3 and 10.4 articulate the requirements that " instruments shall be designed and installed so that normally imposed loads plus loads imposed by the design basis earthquake will not cause failure or E. functional degradation of instruments or control system
" performance."
The majority of instruments at SQN are mounted on seismically qualified local panels which are floor-mounted. Where space requirements preclude the use of local panels, small wall-mounted panels are also used for instruments. Seismic qualification of these instruments and their supports is addressed in Sequoyah Element Report 223.3(B). Concern about lack of typical installation detail drawings for instruments is covered in Sequoyah Element Report 80501-SQN, " Engineering Document Quality." The followirig discussion, therefore, focuses only on aspects of instrument mounting brackets, as stated in Section 1.
Drawing 47W600-14 shows details of a typical local instrument panel frame bolted to the floor. The horizontal channel members of the frame are a combination of light Unistrut channels. The 1/4-inch thick modular mounting plate (detail A14) types 'A' through 'R' are bolted to the channels and, in turn, directly support a wide variety of instruments. However, some panel mounted instruments require additional brackets for mounting because of their physical characteristics. These brackets and the instruments are the subject of the concern. The individual weight of the instruments that require brackets seldom exceeds 50 pounds. Mounting bracket details for specific instruments are shown on the TVA 47W600 series drawings. The drawings indicate bracket thicknesses in the range b of 0.09 to 0.125 inch with holes and/or slots for mounting 05740 - 12/05/86
TVA EMPLOYEE CONCERNS REPORT NUMBER: 223.2(B)
SPECIAL PROGRAM REVISION NUMBER: 0 h PAGE 5 0F 9 using 1/4-inch to 3/8-inch bolts. The bracket are also generally about 3 inches wide and 8 inches long. The bracket designs were normally based on suppliers' recommendations and were performed in the mid-1970s. In other cases, the support brackets for lightweight instruments were frequently designed using " good" engineering judgment without detailed calculations for normal operating and seismic conditions. This was the nuclear industry practice at that time.
The evaluation team has reviewed the details of brackets on the design drawings and has made plant walkdowns. The team has determined that the following specific instruments with lightweight brackets and corresponding design details of the 47W600 series drawings are relevant to the concern.
47W600 Series Instruments Drawing No. Detail j
l Foxboro transmitters 19 B SIRC0 press, diff. switch 21 G Conoflow filter 22 C Kerotest valve manifold 22 G
(.' Drain valve 23 G and H 33 B Beckman transmitters ITT Barton Model 763 293 K The team has also reviewed the structural aspects of these
' brackets. The steel brackets for the instruments are light gage, because the design dead and seismic loads are small. The brackets, therefore, are adequate to support instruments for the design loads. This adequacy was confirmed by the evaluation team performing a sample calculation for 1/8-inch-thick bracket for Foxboro pressure transmitter No. EllGM.
Instrument brackets are sufficiently strong to serve their design function under the most severe design condition, but they are not immune to abuse. The concern that " constant bumping into, leaning against and sitting on these brackets / instruments causes damage" is plausible. Such damage was observed and reported on two instrument models in September 1985 at WBN (App. A, 5.h). To alleviate the problem, NUC PR at WBN decided to replace the brackets for these Foxboro pressure transmitter models with 1/4-inch thickness instead of 1/8-inch thickness as an enhancement to the original design.
2 e
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 223.2(B)
SPECIAL PROGRAM REVISION NUMBER: 0 h_
PAGE 6 0F 9 At SQN, after reviewing a list of Construction and Engineering NCRs and SCRs and af ter interviewing the responsible cognizant engineers, the evaluation team has not identified any case of reported damage to Category I instrument support brackets. Accidental minor bumping into instruments would not produce significant stresses in brackets and would not cause any permanent residual stresses. Inadvertent mistreatment of instruments and their brackets could, however, produce stresses significantly beyond the elastic design limit. So this issue, although unlikely, becomes an important plant maintenance issue.
In view of the fact that there is no reported damage to instruments at SQN, the evaluation team considers this not to be an SQN restart issue.
TVA had requested Gilbert / Commonwealth Associates (G/C) to review the technical adequacy of design changes performed at SQN after the issuance of the operating license. Among other tasks, in March 1986, G/C reviewed completeness of engineering design drawings showing installation details of locally mounted Category I instruments. The G/C report stated that the drawings did not clearly show the method of fastening the instrument mounting plates to the panel frames. In pa response to the G/C recommended action, TVA has committed to perform field walkdowns of all instrument panel frames supporting Category I instruments and to ensure that adequate fasteners with appropriate torque values are used ( App. A, 5.c, Technical Issue No.10).
Lack of typical installation detail drawings was also a subject of another employee concern. Element Report 80501-SQN addressed that concern and also recommended walkdowns prior to restart to verify proper installation of all safety-related instruments. TVA has committed that the corrective action plan, which is in the planning stage, for element 80501 will also incorporate the requiremen' 'h it any damage to instruments and brackets be identified in th. ens (App. A, 7.e).
Findings:
The alphabetic identifiers listed below correspond to the list of issues in Section 1.
- a. Instrument mounting brackets at SQN are adequate to meet their most severe design conditions.
- b. In heavy traffic areas, the issue that the brackets are susceptible to abusive treatment resulting in damage to brackets and instruments is valid.
(' c. If the walkdown discloses damaged brackets, they should be strengthened or protected.
0574D - 12/05/86
8 l TVA EMPLOYEE CONCERNS REPORT NUMBER: 223.2(B)
SPECIAL PROGRAM REVISION NUMBER: 0 PAGE 7 0F 9
Conclusion:
Category I instrument installation at SQN meets the FSAR and TVA's design commitments. Inadvertent mistreatment of instruments is a valid plant maintenance issue but not a design issue. The evaluation team, therefore, concludes that this is not an SQN restart issue.
- 10. CORRECTIVE ACTION:
The corrective action plan for Element Report 80501-SQN already addresses potential damage to instruments and their brackets.
Therefore, no additional corrective action is required.
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- TVA EMPLOydE CONCERNS REPORT NUMBER: 223.2(B)
SPECIAL PROGRAM REVISION NUMBER: 0 PAGE 8 0F 9
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APPENDIX A
- 5. DOCUMENTS REVIEWED RELATED TO THE ELEMENT:
47W600 Series, revisions as of 09/20/86
- c. Gilbert / Commonwealth, Inc., " Final Report - Technical Review of SQN Modifications," G/C Report No. 2614(03/03/86)
" Engineering Document Quality," (09/24/86)
- f. TVA Employee Concerns SON Element Report No. 223.3(B) R0,
- " Local Instrument Seismic Qualification," (11/20/86)
, 9~ g. TVA Employee Concerns WBN Element Report No. 223.2,
- (M " Instrument Mounting Brackets," (06/03/86)
(09/03/85)
- i. Foxboro Catalog, "N-Ell and N-E13 Series Nuclear Electronic Pressure Transmitters," No. PSS 9-181 A (1983)
J. TVA memo from P. R. Wallace to H. L. Abercrombie, I (S53 860418 999), "SQN - GCTF Finting - Employee Concern No.
IN-85-463-006," (04/30/86) l I 6. WHAT REGULATIONS, LICENSING COMMITMENTS, DESIGN REQUIREMENTS OR OTHER APPLY OR CONTROL IN THIS AREA?
- a. SQN FSAR update through Amendment 3, Section 3.10, " Seismic Design of Category I Instrumentation and Electrical Equipment" L b. TVA SQN, " Design Criteria for Mechanical Auxiliary Instrumentation Room Panels," SON-DC-V-10.3, R0 e
! Class I Equipment," SQN-DC-V-10.4, R0 I b y
05740 - 12/05/86 I '
TVA EMPLOYEE CONCERNS REPORT NUMBER: 223.2(B)
SPECIAL PROGRAM REVISION NUMBER: O C PAGE 9 0F 9 APPENDIX A (cont'd)
- 7. LIST REQUESTS FOR INFORMATION, MEETINGS, TELEPHONE CALLS, AND OTHER lit 5 TOSS 10NS RELATED TO ELEMENT.
- a. Review of ECTG Files, Documentation of concern IN-85-973-002, (10/14/86)
- c. Walkdown in the Sequoyah Unit 1 Reactor and Auxiliary Buildings, by the evaluation team on 09/18/86
- d. TVA Transmittal #162, Item 4 (12/01/86)
- e. Telephone call from N. Shah, Bechtel, to A. Smith, TVA, IOM 433(12/03/86)
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C 0574D - 12/05/86
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REFERENCE - ECPSI20J-ECPSI21C TENNESSEE VALLEY AUTHORITY PAGE - 105 , .
FREQUENCY - REQUEST OFFICE OF NUCLEAR POWER RUN TIME - 12:57:19-()
ONP - ISSS - RHM EMPLOYEE CONCERN PRDGRAM SYSTEM (ECPS) RUN DATE - 12/02/86 .
. LIST OF EMPLOYEE CONCERN INFORMATION ,
CATEGORY: EN DES PROCESS 8 OUTPUT SUBCATEGORY: 22302 INSTRUMENT MOUNTING BRACKET
() S GENERIC ' KEYNORD A H APPL QTC/NSRS P KEYWORD B t CONCERN SUB R PLT BBSH INVESTIGATION S CONCERN KEYNORD C NUMBER CAT CAT D LOC FL0B REPORT R DESCRIPTION . KEYNORD D
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I IN 973-002 EN 22302 S HBN NNYY SR TYPICAL INSTRUMENT MOUNTING BRACKETS DESIGN PROCESS l T50156 MP 70601 K-FORM CONSISTING OF THIN GAUGE, PERFORATE INSTALLATION D SHEETMETAL (OR SIMILAR MATERIAL) A INSTRUMENTATION
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l RE NOT STRONG ENOUGH TO SUPPORT THE INSTRUMENTS CGENERIC FOR TYPICAL MOU MOUNTING '
NTS). CONSTANT BUMPING INTO, LEANIN G AGAINST, AND SITTING.ON.THESE BRAC
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l KETS/ INSTR. CAUSES DAMAGE TO BOTH BR ACKETS.AND INSTRUMENTS. CI COULD NO i T PROVIDE SPECIFIC INSTRUMENT NUMBER l
S, LOCATIONS, ETC., BUT STATED ALL S
() UCH INSTALLATIONS SHOULD BE SUBJECT TO RE-DESIGN. THIS HAS REPORTED TO MANAGER (KNOWN) BUT NO ACTION HA
() 1 CONCERNS FOR CATEGORY EN SUBCATEGORY 22302 I
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