ML20149D591
| ML20149D591 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 02/04/1988 |
| From: | Beck J, Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| RTR-REGGD-01.029, RTR-REGGD-1.029 CP-85-29, TXX-88171, NUDOCS 8802090557 | |
| Download: ML20149D591 (4) | |
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9 MEE Lon # TXX-88171 File # 10110
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903.7 1UELECTRIC February 4,1988 w mi.. c. co. a cmwa, er,a,,,,
U. S. Nuclear Regulatory Commission Attn:
Document Control Desk Washington, D.C.
20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION DOCKET NOS. 50-445 AND 50-446 DESIGN OF ARCHITECTURAL FEATURES SDAR:
CP-85-29 (SUPPLEMENTAL REPORT)
Gentlemen:
On September 12, 1985, by our letter logged TXX-4552, we notified you of a deficiency involving inadequate consideration of non-seismic to seismic interaction effects in the design of architectural features which we deemed reportable under the provisions of 10CFR50.55(e).
This item was subsequently identified by our letter logged TXX-6435, dated May 13, 1987 as an item for which a final report had been issued.
However, the originally scheduled completion date for the implementation of corrective actions has elapsed but the implementation of those actions is still in progress.
This report supersedes the information provided in our report IXX-4552.
DESCRIPTION OF DEFICIENCY Issue Specific Action Plan (ISAP) II.d of the Comanche Peak Response Team (CPRT) Program Plan addresses technical issues and allegations transmitted to TV Electric by the NRC concerning non-seismically designed ceiling elements installed in the control room. As part of_their findings, the NRC's letter to TV Electric, dated September 18, 1984, required TV Electric to provide the results of an analysis which demonstrates that structural failures of other Category 11 and non-seismic structures, systems and components in the plant, are reviewed for the effect of failure on safety related structures, systems, and components.
Regulatory Guide 1.29 requires that non-safety related items be designed in such a way that their failure does not adversely af fect the function of safety-related equipment.
During a review performed in support of the NRC Technical Review Team (TRT) effort, the effects of non-seismic-to-seismic interactions were observed to be inadequately considered in the design of architectural features.
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O TXX-88171 february 4,1988 Page 2 of 4 This deficiency resulted from inadequate consideration of seismic loading in the design of architectural features at CPSES.
No evidence existed that architectural features were reviewed for ti" effects of their failure subsequent to the seismic event and the consequence of these failures on safety-related structures, systems, and components.
Other non-architectural equipment, structures, and components affected by the deficiencies are Train C junction boxes, Class 5 piping and associated supports designed using a nomograph, relative building motion effects and comodities attached to secondary walls.
SAFETY IMPLICATIONS The failure to consider the catastrophic failure of architectural features during a seismic event creates the potential for safety-related com3onents/ systems to be adversely affected by the effects of the arc iitectural features' f ailure.
This condition has the potential to adversely affect safe plant operation.
CORRECTIVE ACTION in order to address this deficiency, the CPRT elected to conduct a design verification of the seismic interaction portion of the Systems Interaction Program (SIP) which is utilized to address potential damage to safety-related items caused by interaction with non-Category I items.
Seismic Category 11 is a CPSES design designation (FSAR Section 3.2.1.2) which is used to categorize non safety-related systems, structures and components whose seismic failure could adversely affect safety-related comodities.
It is used to provide a design basis for commodity anchorage and structural adequacy for non-safety commodities which will be located in or near areas containing safety-related comodities.
All comodities designed in accordance with this designation are explicitly evaluated to assure adequate seismic restraint and are attached to supports and embedments designed to Category 11 standards.
This approach provides maximum flexibility of comodity placement i
during layout development.
The Seismic Category 11 design approach has been used at CPSES as the method of satisfying Regulatory Guide 1.29 requirements.
Non-safety features are upgraded to a Seismic Category 11 Design standard whenever design features are identified for which gross catastrophic failure must be considered and that failure af fects the ability of adjacent safety-related comodities to perfonn their intended functions.
These non-safety features are designed and constructed to accepted industry practice, and as such, have been shown historically to demonstrate inherent i
seismic resistance, given proper anchorage.
Therefore, the failure of such features is prevented.
TXX-88171 February 4, 1988 Page 3 of 4 The following Seismic Category 11 architectural features were evaluated and modified where necessary to assure adequate seismic restraint or to alleviate any unacceptable interactions:
a) flourescent lighting fixtures b
Incandescent lighting features c
Horns, speakers, and smoke detectors d
Sheet rock walls e)
L. adders f
Aluminum panels and architechtural flushings/ trims g
fiberglass overlay sheets h
Handrails Review and analysis activities have been performed to evaluate the potential effects on Seismic Category I items as follows:
Watertight doors were originally seismically designed.
A review of the o
specification has assured that the appropriate design criteria were included.
Bullet and Missile Resisting Doors were not originally seismically designed.
A review of the applicable specifications for both door types has assured that the design loads were enveloped by the seismic loads.
Analyses, as required, were performed as discussed in STIR-CPRT-S-007, "Doors and Security Barriers."
Hollow Metal, Wire Mesh, and Rolling Steel Doors are required to meet normal (non-nuclear) industrial standards in accordance with the l
applicable specifications arovided in STIR-CPRT-S-007.
A review of the I
applicable specifications las assured that the design loads were i
enveloped by the seismic loads.
Analyses were perfomed as required.
I 1
The existing designs of grating and checkered plate are seismically l
o qualified.
The construction of checkered plate items meet the l
requirements of Regulatory Guide 1.29 and the FSAR Section 3.78.2.8.
The review of grating configurations and the installation of seismically qualified hold-down details has assured compliance with these same requirements.
The following actions are being performed to address non-architectural equipment, structures and components affected by the deficiencies:
a)
Train C junction boxes are currently being evaluated for seismic adequacy in conjunction with the Post-Construction Hardware Validation Program (PCHVP). Under this program any Train C junction box determined to be seismically unacceptable will be modified by Design Change Authorizations.
This issue is being addressed by 50AR CP-85-36, "Train
'C' Conduit Supports," for Train C conduit less than 2 inches in diameter and 50AR CP-85-34, "Conduit Support Design," for Train C conduit greater than 2 inches in diameter.
4 4
TXX-88171 February 4, 1988 Page 4 of 4 b)
Validation of Class 5 piping and supports is being performed in conjunction with the PCHVP under Field Validation Method CPE-FVM-CS-068 i
and Project Procedure CPPP-30, Rev.1. -Under this program, Design Change Authorizations will be issued as necessary to provide the required-seismic adequacy.
c)
Commodities attached to secondary walls and relative building motion are addressed in SDAR-86-12 "Commodity Installations at Secondary Wall Design Gaps." During our evaluation, we have confirmed the secondary walls are structurally adequate and the wall displacements have no effect on attached connodities (see TXX-88204).
No further action is required on this item.
All of the items listed above either comply (architectural) or will comply (non-architectural) with Regulatory Guide 1.29 as discussed in STIR-CPRT-S-008, "STIR for ISAP ll.d," Revision 0.
1 The SIP grot.p has been established for assessing credible failure mechanisms for non-seismic structures, systems, or components designated by the SIP group as interacting with safety related structures, systems, or components subsequent to the seismic event at CPSES.
This is an in-1rocess review program at CPSES and is scheduled to be completed by Marc 1 1, 1988.
In
[
addition, design control procedures now assure that interdisciplinary review of new and modified designs is performed to properly incorporate design requirements.
Records supporting our conclusions concerning reportability and corrective action implementation will be 3vailable for you inspectors review upon completion of the Systems Interaction Program (SIP) at CPSES.
Very truly yours, j
W. G. Counsil By:_
?
Joh6 W. Beck l
4 Vice President, Nuclear Engineering CBC/grr I
c-Mr. R. D. Martin, Region IV ResidentInspectors,CPSES(3) l i