TXX-4054, Interim Deficiency Rept Re Temp in Excess of FSAR Parameters Experienced in Annulus Between Reactor Vessel Insulation & Shield Wall.Cooling Increased by Reducing Chilled Water Temp & Installing Addl Cooling Coil
| ML20085J654 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 09/26/1983 |
| From: | Gary G TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | Madsen G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, TXX-40540.55E, NUDOCS 8310130268 | |
| Download: ML20085J654 (2) | |
Text
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TEXAS UTILITIES GENERATING CO.TIIRNY INN 11 DIW \\N "IT M Elt f MlJ.WTEN %M 7T32OINT4 September 26, 1983 n.a.cany "lJ;U:.n'":!!l '
TXX-4054 -
Mr. G. L. Madsen, Chief Re&ctor Project Branch 1 U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement 611 Ryan Plaza Drive, Suite 1000 Docket Nos.:
50-445 Arlington, TX 76012 50-446
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COMANCHE PEAK STEAM ELECTRIC STATION CONTAINMENT BUILDING COOLING QA FILE:
CP.-83-18, SDAR-118
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Dear Mr. Madsen:
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In accordance with 10CFR50.55(e), we are submitting the enclosed report of actions taken to correct a deficiency regarding high temperature conditions in the reactor vessel support and neutron detector well areas.
We have submitted interim reports logged TXX-4033 and TXX.4042, dated August 25, 1983 and September 6, 1983, respectively.
Supporting documentation is available at the CPSES site for you Inspector's review.
Very truly yours, RJG:ln cc: NRC Region IV - (0 + 1 copy)
Director, Inspection & Enforcement (15 copies)
U.S. Nuclear Regulatory Commission Washington, DC 20555 6 7 I
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B310130268 830926 9
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TXX-4054 S;ptember 26, 1983 ATTACHMENT CONTAINMENT BUILDING COOLING DESCRIPTION During start-up testing, temperatures in excess of FSAR parameters were experienced in the annulus between the reactor vessel insulation and shield wall.
Specifically, temperatures of 3140F were observed in the reactor vessel support and neutron detector well areas.
The failure to meet the acceptance criteria was documented by test deficiency reports. Efforts to correct the condition during testing were not successful.
Examination of the condition yielded two areas of concern.
First, the area between the reactor vessel insulation and cavity wall was unduly restricting air flow; and secondly, the quantity of heat being removed by the cooling system was in excess of the design heat load (550,000 to 600,000 BTU /Hr. vs.
250,000 BTU /Hr.).
SAFETY IMPLICATIONS In the event the condition had not been detected during start-up testing, the integrity of the reactor vessel shield wall could not be assured after long-term exposure to elevated temperatures.
In addition, the sensitivity of the source range detectors in the neutron detector well area could not be assured.
CORRECTIVE ACTIONS Site engineering has determined the temperature experienced during the test does not exceed concrete specification conditions for :hort term loading.
In addition, bubsequent retests of the detectors by start-up has indicated no detrimental effects.
No further action is planned for these items.
The capacity of the hooling system will be increased by reduction of the chilled water temperature and the lipstallation of additional chilled water cooling coils. By removing construction debris and rework of the vessel insulation support channel, the air flow restrictons between the reactor vessel insulation and shield wall will be relieved.
These modifications will be implemented prior to fuel load.