ML20045G724
| ML20045G724 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 07/07/1993 |
| From: | Fenech R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9307150103 | |
| Download: ML20045G724 (4) | |
Text
[..'.
.p r
e d
Tennessee Vailey Authoi.ty. Post Off ce Don PfXY1 Soddy-Day. Tennenee 37379 2000 4
Robert A Fenech V ce President. Sequoyah Nuc! ear Plant July 7, 1993 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen!
In the Matter of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 SEQUOYAll NUCLEAR PIANT (SQN) UNITS 1 AND 2 - CORRECTIVE ACTION PLAN (CAP)
CORRECTIVE ACTION TRACKING DOCUMENT (CATD) 223.03-SQN-01
Reference:
Letter from Mark 0. Medford to NRC dated February 26, 1990, "Sequoyah Nuclear Plant (SQN) - Employee Concerns Task' Group (ECTG) - Signiitcant Deviation to' Corrective Action Plan (CAP) for Corrective Action Tracking Document (CATD) 223.03-SQN-01" The purpose of this letter is to withdraw the CAP deviation request for the subject CATD as provided in the referenced letter.
Upon further review, only instrumentation associated with the heating, ventilation, and air conditioning (HVAC) system did not have the required mounting detail drawings and seismic analyses documentation.
TVA will process a deviation request in accordance with the Employee' Concerns Special Program, based upon the information contained in the enclosure, to revise the corrective action for the subject CATD to the remaining IIVAC system components.
If you have any questions concerning this submittal, please telephone R.11. Shell at (615) 843-7170.
Sincerely, Md Robert A. Fenech 130155 Enclosure cc: See page 2 9307150103 930707 E}
AOg[
4 ff P
' -ADOCK 05000327 PDR PDR $
U.S. Nuclear Regulatory Commission Page 2.
5 July 7. 1993 Enclosure cc (Enclosure):
Mr. D. E. LaBarge, Project Manager U.S. Nuclear-Regulatory Commission.
One White Flint, North 1
11555 Rockville Pike Rockville, Maryland 20852-2739 NRC Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy-Daisy Tennessee 37379-3624 Regional Administrator U.S. Nuclear Regulatory Commission Region'II-
)
101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323-2711 I
P k
e
,a
.m
.e
.n.,
~
7 ENCLOSURE
~
BASIS TO REVISE Tile CORRECTIVE ACTION FOR CORRECTIVE ACTION TRACKING DOCUMENT (CATD) 223.03-SQN-01 Introduction CATD 223.03-SQN-01 was generat,d as a result of a concern at Watts Bar Nuclear Plant that Unit 1 local instruments were installed based on good engineering judgement but without a seismic analysis.
For the purpose of this letter, the safety-related instruments are divided into the following three categorics:
1.
Accident mitigation or safe shutdown instruments 2.
Critical structures, systems, and components instruments; technical specification instruments; and technical specification compliance instrumentation 3.
Instruments that do not perform a safety-related function but receive 1E power only liardwarfLRe.vlewa llefore the 1988 restart of each unit at Seguoyah Nuclear Plant (SQN), TVA established the seismic adequacy of field-mounted, safety-related lustruments that perform accident mitigation or safe-shutdown functions (Category 1).
SQN evaluated 430 instruments as a result of this effort.
TVA identified 109 instruments that did not have mounting-detail drawings. All of the 109 instruments were heating, ventilation, and air conditioning (HVAC) system instruments. Engineering evaluations of the mounting for the 109 instruments were performed and detennined to be acceptable as-is.
Drawings for the mounting schemes were also issued.
An additional review of the Category 2 safety-related instruments was i
performed. An additional 27 instruments (all HVAC), out of the total i
population of 199, were identified that did not have mounting details or seismic analysis of the mounting configurations.
a Analysis _nL_Re.sulta i
A review was perfonned to identify the difference with the design process for the llVAC instruments.
The initial design process for HVAC instruments was different in that these instruments were not included in the 47W600 drawing series, which is typically where instrument mounting details are documented. The design process was that Mt-hanical Engineering specified the system operating requiremente. including setpoints, limits, and required accuracies. Mechanical Engineering was to transmit those requirements to the Instrumentation and Controls (I&C) section for instrument selection and installation details.
The HVAC instruments were not forwarded to ILC and the subsequent design activities, including mounting details, were not developed.
l
~
s _.
- -..-,_~.
+
Conclusions Based on the hardware reviews and analyses performed, the seismic qualification documentation problem is limited to HVAC system-instruments. Nonconformances identified.to date have not impacted operability of any of the HVAC system instrumentation. Walkdowns'of the remaining Category 3 HVAC instruments'are complete. Seismic adequacy evaluations have been performed and the instrument mountings were determined to meet design criteria requirements. Drawings for the mounting details have been issued.
Based on the above discussion, the remaining Category 3 instruments will not be reviewed to. confirm that mounting details and seismic analyses are retrievable. A deviation request will be processed in accordance with the Employee Concerns Special Program to revise the corrective action to include the actions that have been performed.
Recurrence Control TVA has established and implemented Engineering Requirements Specification ER-SQN-EEB-01.
This specification requires' seismic qualification documentation for modifications that alter existing configuration. As maintenance is performed on these instruments, which involves removal and remounting, the work must be performed in accordance with the as-configured drawings.
If the configuration is not in-accordance with the drawings or drawings do not exist, an evaluation of the component operability, including seismic qualification, is performed.
i 1
u
.a---.
_..