ML20246F740
| ML20246F740 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 05/05/1989 |
| From: | Fox C TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 8905150075 | |
| Download: ML20246F740 (5) | |
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TENNESSEE VALLEY AUTHORITY CHATTANOOGA ~, TENNESSEE 37401
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SN 157B Lookout Place j
.MAY 051989 U.S. Nuclear Regulatory Con'ission ATTN: Document Control Desk Washington, D.C.
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Gentlemen:
In the Matter of
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Docket No. 50-328 Tennessee. Valley Authority
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SEQUOYAH NUCLEAR PLANT (SQN) - RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING FIRST-TEN-YEAR INSERVICE INSPECTION (ISI) PROGRAM FOR UNIT 2
Reference:
NRC letter to TVA dated March 21, 1989, " Request for Additional Information, First Ten-Year Inservice In:pection Program, Revision 13 (TAC 59458) - Sequoyah Nuclear Plant, Unit 2" By the reference letter, NRC requested additional information regarding TVA's' I
Revision 13 of the SQN unit 2 ten-year ISI program.
This l'nformation was requested to support the completion of NRC review of this program.
Enclosed is the requested information to support NRC review of TVA's ISI program for SQN unit 2.
Please direct questions concerning this issue to D. V. Goodin at (615) 843-7734.
Very truly yours, TENNESSEE VALLEY AUTHORITY I
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C. H.
ox, Jr., Vice President and
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Nuclear Technical Director l
Enclosure cc: See page 2 l
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$$$"S$8c0$$0Shge An Equal opportunity Employer
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b.S. Nuclear.RegulatoryCommission MAY 051989 cc (Enclosure):
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Ms. S. C. Black, Assistant Director for Projects TVA Projects Division U.S. Nuclear Regulatory Commission i
One White Flint, North j
l 11555 Rockville Pike Rockville, Maryland 20852 l
Mr. B. A. Wilson, Assistant Director for Inspection Programs TVA Projects Division l
U.S. Nuclear Regulatory Commission l
Region II 101 Marietta Street, NH, Suite 2900 Atlanta, Georgia 30323 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379 I
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x ENCLOSURE Additional Information Regarding First 10-Year' Inservice Inspection (ISI) Program, Revision 13, Sequoyah Nuclear Plant Unit 2 L.
l NRC Question'2.0(a)
" Code case N-356, proposed for use in Section 4.0 of the ISI program, is not approved for-use in Regulatory Guide 1.147.
Please provide justification for your need to use this code case."
TVA Response TVA utilized code case N-356 after its approval for use by NRC in Reference 5.
TVA requested the use of code case N-356 solely.as a cost-saving measure. Code case N-356 extended the decertification requirement for level III nondestructive examiners to 5 years.
IWA-2300, paragraph a(1), of the American Society of Mechanical Engineers (ASME) Code,Section XI.(1977 edition through summer 1978 addenda), requires decertification of all level III examination personnel every 3 years.
TVA proceduralized the use of code case N-356 to incorporate it into the ISI program on January 23, 1989.
NRC Question 2.0(b)
" Relief Request ISI-3 requests relief from 100'f. examination of Class 1 and 2 piping welds (ASME Section XI Categories B-F, B-J, and C-F).
However, in the l
weld listing table attached to Relief Request ISI-3,' only Class I welds are listed. Please provide a list of all Class 2 welds for which relief is requested under Relief Request ISI-3."
TVA Response To date, TVA has only identified code Class I welds as requiring request for relief (welds determined to be impractical to examine).
Based on SQN design and as more welds are scheduled for examination TVA anticipates adding more code Class 1 and some code Class 2 welds to the ISI-3 relief request listing.
Additional welds will be identified in ISI-3 as required.
It should be noted that the listing of welds in ISI-3 was provided in response to Question 6 of Reference 8.
TVA's commitment to amend ISI-3 to identify
-exam limitations on a weld-by-weld basis was provided by Reference 7.
NRC Question 2.0(c)
"NRC Safety Evaluation Reports dated March 31, 1988... and May 11, 1988... reviewed TVA's program for control of microbiologically induced corrosion (MIC) in the essential raw cooling water (ERCW) system.
As a result of these reviews, the NRC required a program of augmented inservice inspections of the ERCH system as follows:
1.
A semi-annual weld-by-weld visual inspection program to identify leaking welds. Upon leakage detection, a radiographic examination to determine the extent of MIC degradation in the weld volume shall be performed, f
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2.
Along with the above inspections, the following additional items are required:
(a) at the same time leakage is detected, an assessment is made to ensure the acceptance criterion is not exceeded prior to the scheduled outage or repair; (b) the frequency of direct visual inspection of weld i
specific leaks is increased to monthly; and (c) the leakage from a weld does not exceed 0.5 gpm and the total leakage from all welds does not exceed 1 gpm.
This augmented inspection for the ERCW system is not mentioned in the ISI program.
Please verify that the required inspections on the ERCW system will be performed as part of the Sequoyah, Unit 2 augmented ISI plan."
TVA Response As stated in TVA letters to NRC (References 2, 3, and 6), the implementation of TVA's MIC program at SQN for the ERCW system was to be addressed under prevent've maintenance (PM) Instructions 2220, 2221, 2222, ar.d 2223 and Technical Instruction (TI) 109, " Nondestructive Testing of Etainless Steel Butt Welds to Assess Damage Resulting from Microbiologically Induced Corrosion." It is important to note that in paragraph 3.0, as contained in, to Reference 4, NRC stated, "The staff' concludes that TVA's inspection, evaluation and repair program for MIC for the ERCH austenitic stainless steel piping, if properly implemented, provides reasonable assurance that the ERCW system is capable of performing its intended safety function."
The surveillance and inspection program for SQN's MIC program will be controlled using TI-109 and the associated PM instructions referenced above.
TVA has no plans of including the MIC program under the augmented ISI program for either unit.
It should be noted that item 2(c) above states that " total leakage from all welds does not exceed 1 gpm."
By reference 1, NRC approved a higher total leakage amount not to exceed 2 gallons per minute.
This change was discussed in a May 6, 1988, telephone conference call between R. Hermann, of NRC, and TVA management.
References 1.
NRC letter to TVA dated May 11, 1988, " Request for Relief from ASME Boiler i
and Pressure Vessel Code,Section XI, :nservice Inspection Program" 2.
TVA letter to NRC dated May 4, 1988, "Sequoyah Nuclear Plant (SQN) Units 1 i
and 2 - Clarification of SQN's Microbiologically Induced Corrosion (MIC)
Program" i
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TVA letter to NRC dated April 4, 1988, "Sequoyah Nuclear Plant (SQN) Units 1 and 2 - Request for Relief from the American Society of Mechanical Engineers (ASME)Section XI Code As It Relates to SQN's Microbiologically Induced Corrosion (MIC) Program" 4.
NRC letter to TVA dated March 31, 1988, " Safety Evaluation of Microbiologically Induced Corrosion (MIC) Program" i
5.
NRC letter to TVA dated January 25, 1988, "Use of ASME Boller and Pressure Vessel Code Cases N-341 and N-356 (TAC R00258-R00226)"
6.
TVA letter to NRC dated January 20, 1988, "Sequoyah Nuclear Plant (SQN)
Units 1 and 2 - Microbiologically Induced Corrosion (MIC) Program" l
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TVA letter to NRC dated March 12, 1986 8.
NRC letter to TVA dated November 18, 1985, "Sequoyah Nuclear Plant, Units 1 and 2 - Review of Inservice Inspection Program, Dequest For Additional Information" l
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