ML20087P963
| ML20087P963 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 04/05/1984 |
| From: | Tucker H DUKE POWER CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8404100155 | |
| Download: ML20087P963 (3) | |
Text
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o Dmm POWER GomNY 15.0. Ilox W1180 CIIAHLOTTE, N.C. 28242 HALB. TUCKER TE RE PIIONE
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April 5,1984 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Ms. E. G. Adensam, Chief Licensing Branch No. 4 Re: Catawba Nuclear Station Docket Nos. 50-413 and 50-414
Dear Mr. Denton:
Section 6.2.6 of the Catawba Safety Evaluation Report discusses Confirmatory Item 17, Justification for Not Testing Certain Isolation Valves. Catawba FSAR Table 6.2.4-1 identifies those penetrations that would be vented and drained during a Type A test. For a certain group of these penetrations, it was determined that venting and draining were not appropriate, and would give excessive Type A test results.
The containment penetrations identified in Attachment 1 are those which have a " reverse" check valve bypassing the inside containment isolation valve (which affords post-accident overpressure protection) and which have both " process" containment isolation valves receiving a sealing fluid from the Containment Valve Injection Water System. The " process" containment isolation valves are not required to be vented to containment atmosphere during the Type A test since they receive a fluid seal. The " reverse" check valves cannot be excluded from the venting and draining requirement on this basis since they are not assured of receiving the fluid seal.
In order to properly drain and vent the " reverse" check valves, the " process" containment isolation valves must also be drained and vented.
In addition, the fluid seal system to the " process" containment isolation valves must be isolated to assure that the " reverse" check valves remain exposed to containment atmosphere. As a result there is an unaccaptable amount of air leakage through the " process" containment isolation valves. This gives false indica-tion that leakage through components which could be exposed to post-accident containment atmosphere is excessive and that Type A test results are unsatisfactory.
In order to exclude leakage through " process" containment isolation valves which receive a sealing fluid, Duke Power Company proposes to not drain or vent the penetrations listed in Attachment 1 during Type A testing. Recog-nizing that the " reverse" check valves are a potential leak path we propose to add the leakage rate for the " reverse" check valves as detennined by their Type C test results to the leakage determined by the Type A test. Since Type C testing is performed with air at virtually the same pressure as a full pressure Type A test, this method will include the leakage which would be c oected if it were possible to vent and drain the " reverse" check valves while maintaining the fluid seal on the process containment isolation valves.
[I 8404100155 840405 I
PDR ADOCK 05000413 A
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Mr. Harold R. Denton, Director April 5,1984 Page 2 Therefore,' Duke Power hereby requests an exemption to 10 CFR 50, Appendix J, III.A.(d), Type A test requirement that certain piping be drained and vented for those penetrations listed in Attachment 1.
As discussed above, the proposed test method presents an acceptable alternative to the Appendix J requirement.
Very truly yours,
- YWS, Agg Hal B. Tucker ROS/php Attachment cc: Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303 NRC Resident Inspector Catawba Nuclear Station Mr. Robert Guild, Esq.
Attorney-at-Law P. O. Box 12097 Charleston, South Carolina 29412 Palmetto Alliance 21351 Devine Street Columbia, South Carolina 29205 Mr. Jesse L. Riley -
Carolina Environmental Study Group 854 Henley Place Charlotte, North Carolina 28207
Item'#(Note 1)
Press. Valves Penetration Function
" Reverse Check Valve" e
07 NV89A, 91B.
RCP Seal. Water Return NV90 45 WL805A, 807B NCDT Pump Disch.
WL806
- 46 WL867A, 869B VUCDT WL868 47 WL825A, 827B Con't Floor Sump Pumps WL321 48 WLA24, WLA21 S/G Drain Pump WLA22 68 RN484A, 487B Lower Con't Return RN485 Hdr.
70 RN429A, 432B Upper Con't Return RN430 Hdr.
1.
Item number provides cross-reference with Catawba FSAR Table 6.2.4-1