ML18153B507
| ML18153B507 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna, 05000000 |
| Issue date: | 10/03/1988 |
| From: | Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 88-433, IEB-88-008, IEB-88-8, NUDOCS 8810070325 | |
| Download: ML18153B507 (4) | |
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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 October 3, 1988 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C.
20555 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 SURRY POWER STATION UNITS 1 AND 2 CONFIRMATORY RESPONSE TO NRC BULLETIN NO. 88-08 Serial No.88-433 NO/NAPS-LIC: jmj R3 Docket Nos.
50-338 50-339 50-280 50-281 License Nos. NPF-4 NPF-7 DPR-32 DPR-37 THERMAL STRESSES IN PIPING CONNECTED TO REACTOR COOLANT SYSTEM Virginia Electric and Power Comp~ny has reviewed piping that connects to the Reactor Coolant System (RCS) in accordance with NRC Bulletin 88-08.
This review has identified lines from the Safety Injection System (SI) that connect to the RCS and could be subjected to stresses from temperature stratification or oscillations as described in the bulletin.
The results of our review are discussed below.
The bulletin also identified a potential concern with thermal gradients in pressurizer surge lines.
We are aware of this concern and have initiated efforts to -evaluate the concern relative to North Anna and
. Surry.
In addition, the Westinghouse Owners Group is considering a project to generically evaluate this concern for Westinghouse plants.
As a result of our review, we have identified the following lines as potentially susceptible to this thermal stress concern:
Surry Unit 1 6"-RC-17-1502 6"-RC-19-1502 SAFETY INJECTION SYSTEM (COLD LEG) 6"-RC-20-1502 6"-RC-16-1502 6"-RC-18-1502 LOW HEAD SAFETY INJECTION (HOT LEG) 6"-RC-21-1502 8810070325 881003 PDR ADOCI< 05000280 Q
Surry Unit 2 6"-RC-317-1502 6"-RC-319-1502 6"-RC-320-1502 6"-RC-316-1502
.6"-RC-318-1502 6"-RC-321-1502 e
North Anna Unit 1 6"-RC-17-1502-Ql 6"-RC-19-1502-Ql 6"-RC-20-1502-Ql 6"-RC-16-1592-Ql 6"-RC-18-1502-Ql 6"-RC-21-1502-Ql North Anna Unit 2 6"-RC-417-1502-Ql SAFETY INJECTION SYSTEM (COLD LEG)
LOW HEAD SAFETY INJECTION (HOT LEG)
SAFETY INJECTION SYSTEM (COLD LEG)
LOW HEAD SAFETY INJECTION (HOT LEG) 6"-RC-419-1502-Ql SAFETY INJECTION SYSTEM (COLD LEG) 6"-RC-420-1,?02-Ql 6"-RC-416-1502-Ql 6"-RC-418-1502-Ql LOW HEAD SAFETY INJECTION (HOT LEG) 6"-RC-421-1502-Ql Our review
- also considered other piping systems which connect to the RCS, including residual heat removal and chemical and volume control.
It was determined that these systems would not be subjected to this type of thermal stress.
An action plan is also being developed to nondestructively examine the affected welds, associated heat affected zones, and any identified high stress locations in each of the susceptible lines.
The concerns identified in Supplement 2 to the bulletin have been considered in the selection of the nondestructive examination techniques.
These examinations will be completed during the current outages for Surry Units 1 and 2.
For North Anna Units 1 and 2, the examinations will be completed during the next refueling outage for each unit, which are currently scheduled for April, 1989 and February, 1989, respecti*\\.rel}T.
}*4s required b~,7 the b-.!lleti~, the results cf the nondestr~cti\\1e examinations will be reported to the NRC within 30 days of completion of the outages in which the examinations are performed.
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In addition, the SI lines which are potentially most susceptible to temperature stratification or oscillations will be selected for temperature monitoring.
The temperature instruments will be placed at high-stress locations in the p1p1ng where potential temperature stratification or oscillations would be expected to be most severe.
Appropriate limits on the temperature distribution at the selected piping locations, and required actions if the limits are exceeded, will be established.
This instrumentation will be installed during the current outages for Surry Units 1 and 2.
For North Anna Units 1 and 2, the temperature monitoring instrumentation will be installed during the next refueling outage for each unit as indicated above.
This program to monitor pipe temperatures in selected lines is considered to be an interim solution to this pipe thermal stress concern.
Long term solutions are being evaluated, including piping redesign, changes in system valve lineups, and installation of permanent monitoring systems.
The results of this evaluation will be submitted by March 15, 1989.
The information provided in this response is true and accurate to the best of my knowledge.
If you have any questions, please contact us.
Vice President - Nuclear cc:
U. S. Nuclear Regulatory Commission 101 Marietta Street, N.W.
Suite 2900 Atlanta, GA 30323 Mr. J. L. Caldwell NRC Senior Resident Inspector North Anna Power Station Mr. W. E. Holland NRC Senior Resident Inspector Surry Power Station
e COMMONWEALTH OF VIRGINIA)
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COUNTY OF HENRICO
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The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by W.
R. Cartwright who is Vice President -
Nuclear, of Virginia Electric and Power Company.
He is duly authorized to execute and file the foregoing document in beha 1 f of that Company, and the statements in the document are true to the best of his knowledge and belief.
Acknowledged before me this 3 day of (/}~/
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My Commission expires:
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