ML20083C749
| ML20083C749 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 09/20/1991 |
| From: | Richter M COMMONWEALTH EDISON CO. |
| To: | Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9109270151 | |
| Download: ML20083C749 (4) | |
Text
Commtnw alth Edis:n 1400 Opus Place Downers Grove, illinois 00515 Septembe,- 20,1991 Dr. Thomas E. Muriey, Director Office of Nucbar Reactor Regulation U.S. Nuclear Regu! story Commission Washington, D.C. 20555 Attn: Document Control Desk
?ubject:
Quad Cities Nuclear Power St
n Unit 2 Submittalof Relief Request Inservice Inspection Progrom NRC_DocM Nr M-265_
References:
(a) Conference Call on September 20,1991 between CECO (M. Richter) and NRR (L. Olshan).
(b)
M. H. RicMor (CECO) to T. E. Murley (NRC) letter dated April 5,1991.
(c)
J. Zwolinski (NRC) to D. Farrar (CECO) letter dated March 31,1986.
Dr. Murley:
As discussed Mth your staff In the Reference (a) teleconference, the '1 B' Inboard Main Steam Isolation Valve (2-0203-18) is being disassembled for maintenance /re air during the current forced maint9 nance outage for Unit 2. As a result of this work, an ASME Cofe Class 1 system leakage test is required by Section XI. Based on the personnel exposure and c"tical path outage im act for the performance of the Class 1 system leakage test at nominal operailng pressure (1000 ps ), Commonwealth Edison Company (CECO) is submitting the attached relief request (CR-17) to the Inservice Inspection (ISI) Progr i. The relief request wiil allow the system leakage test for the
'1B' Inboard Main Steam Isciation Valve to be performed at 920 psig during unit startup. Reference (b) submitted an ISI Prcgtrira relief request (CR-14) wt voc!d address the current situation and avoid case-by-case relief requests; however, it is CECL snderstanding that this request is still under staff review. T he Safety Evaluation Report for the current ten-year ISI Program interval was transmitted by Reference (c).
CECO requests verbal approval of this relief request to support Unit 2 startup which is scheduled for September 22,1991. CECO appreciates the prompt attention that has been given by your staff to this matter.
Please d! rect any questions or comments on this letter to this office.
Respectfully, shW
}
M. H. Richter Nucleal Licensing Administrator l
Attachment:
Relief Request Number CR-17 cc:
A. Bert Davis, Regional Administrator - Region ill
/\\
L.N. Olshan, Project Manager - NRR
\\f T.E. Taylor, Senior Resident inspector - Quad Cities I
oto9270151 910920,
g \\
n-PDR ADOCK0500g, 4
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ATTACHMENT RELIEF REQUEST NUMBER CR 17 FOR QUAD CITIES STATION
/ sci:703:35
REllEE REQUEST _ NUMBER:_ CR-17 COMPONENT _IDENTIElCATION Code Class:
ONE
References:
Article IWA-5211 a Article IWB-5221 a Examination Category:
B-P ltem Number:
815.70
==
Description:==
System leakage test pressure for the Unit 2
'B' Inboard Main Steam isolation Valve (2-0203-18) following bonnet reassembly.
CODELBEQUlBEMENT IWA 5211(a) rec uires a system leakage test to be conducted following opening and reclosing of a component n the system after pressurization to nominal operating pressure.
lWB-5221(a) states that the syst9m leakage test shall be conducted at a test pressure not less than the nominal operating pressure associated with 100% rated reactor power.
BASIS _ EOR _RELIEE During the current Unit 2 forced maintenance outage (September 1991), the '1B' Inboard Main Steam ! solation Valve (2-0203-18) is being disassembled for maintenance / repair. This work requires the disassembly and reassembly of a Class 1 mechanical connection (the valve's bonnet) which 10 located in the drywell and cannot be Isolated from the reactor vessel. For this situation, the performance of a Class 1 system leakage test at 1,000 psig (which is the nominal operating pressure at 100% rated reactor power) would have a significant impact on the unit's critical path outage time and personnel exposure.
The normal Class 1 system leakage test, which is performed wi'h the vessel !!ooded up, requires numerous equipment outages (e.g., in excess of 300 valves must be taken out-of-service, Main Steam safety valves must be gagged). Perfonnance of the equipment outages, coupled with the performance of the system leakage test, takes approximately 5 days (3 shifts per day) with a total personnel exposure of approximately 2.5 Man Rem.
Performance of the system leakage test using reactor pressure during unit startup is possible, however, the test can not be performed at 1,000 psig. During unit startup, the Electro-Hydraulic Control System precludes a reactor pressure above 950 psig whhout significant increases in reactor power. In order to ach eve a pressure of 1,000 psig, the reactor would have to be at approximately 100% rated power. The radiation levels in the drywell at this power level are prohibitive, and prevent drywell entry by plant personnel.
A drywell entry to inspect for leakage can be performed at 920 psig, which is associated with approximately 15% reactor power. Performance of the leakage test in this manner would have an insignificant impact on the ability to detect leaksge from the reassembled mechanical connection. It would also significantly reduce the personnel exposure and critical path outage time required for the test.
/scl:703:36
2 PROEOSED_ALIERNATE.EXAMINAllON For the Unit 2 '1B' Main Steam isolation Valve (2 0203-18) bonnet assembly, the system leakage test will be performed at 920 psig during unit startup.
AEELICABLEllME.EERIOR Relief is requested for the Unit 2 '1B' Main Steam isolation Valve (2-0203-1B) bonret reassembly which is occurring during the current Unit 2 forced maintenance outage. Unit 2 startup is currently scheduled for September 22,1991.
l
/ sci:703:4
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