ML20148N728
| ML20148N728 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 06/26/1997 |
| From: | Leonard T ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| SR-97-002-00, SR-97-2, W3F1-97-0174, W3F1-97-174, NUDOCS 9706300071 | |
| Download: ML20148N728 (4) | |
Text
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A O
Ent:rgy Operati:ns, Inc.
PO Box B Kiitona. LA 70066-0751 Tel 504 464 3120 T.R. "Ted* Leonard STni$NOT waterford 3 W3F1-97-0174 A4.05 PR June 26,1997 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555
Subject:
Waterford 3 SES Docket No. 50-382 License No. NPF-38 Reporting of Special Report Gentlemen:
Attached is Special Report SR-97-002-00 for Waterford Steam Electric Station Unit
- 3. This report provides details of a radiation monitoring instrument having been inoperable for greater than 30 days. This condition is being reported pursuant to Technical Specification Limiting Condition for Operation 3.3.3.1.
Very truly yours, T
T.R. Leonard A19 General Manager Plant Operations TRL/JWC/tjs llll0l!!!!!!!!!)$l)lll)$fllllll Attachment cc:
JE.W. Merschoff (NRC Region IV)l C.P. Patel (NRC-NRR),
A.L. Garibaldi, J.T. Wheelock 'INPO Records Center, J. Smith, N.S. Reynolds, NRC Resident inspectors Office, Administrator - LRPD 9706300071 970626 DR ADOCK 050003 2
Attachmsnt l
W3F1-97-0174 Page 1 of 3 SPECIAL REPORT (SR) 97-00240 RADIATION MONITORING INSTRUMENT INOPERABLE GREATER THAN 30 DAYS Reportable Occurrence Technical Specification (TS) Limiting Condition for Operation (LCO) 3.3.3.1
" RADIATION MONITORING INSTRUMENTATION" requires that with one or more l..
radiation monitoring channels inoperable, take the ACTION shown in Table 3.3-6.
The ACTION for Component Cooling Water (CCW) monitors A and B allows for i
continued operation for up to 30 days provided grab samples are taken once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and these samples are analyzed for gross activity within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The TS
- further states that if the monitor is not restored to OPERABLE status within 30 days after the failure, continue sampling and prepare and submit a Special Report pursuant to TS 6.9.2 within 14 days. This Special Report is being submitted due to
' CCW monitor 'B' being inoperable for greater than 30 days as of June 12,1997.
Initial Conditions i
At the time of the discovery, Waterford 3 was in Mode 6, Cold Shutdown, conducting I
Refueling Outage 8 activities. Technical Specification LCO 3.3.3.1 was entered May
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13,1997 due to CCW monitor 'B' having been isolated and declared inoperable.
Event Descriptig On May 13,1997, Waten'ord 3 Engineering personnel identified a design
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discrepancy for the 'B' CCW train radiation monitor. The location of the tap for the cooling water to the sample heat exchanger is such that cooling water would be
- isolated by certain accider t actuation signals. Furthermore, a pathway for cross-connection would exist after different actuation signals.
Waterford 3 design provides for two redundant trains of CCW for removing essential and non-essential heat loads from the plant. The two trains are separated by a l
header with two isolation valves, CC-200A and CC-200B. Each train has a radiation monitor designed to detect leakage during normal operation, anticipated operational-occurrences, and certain accident conditions from those components that are cooled by CCW and contain radioactivity. During these conditions the two isolation valves are open, allowing cross flow between the trains. A surge tank with a compartment for each train is provided for level fluctuations and for pump head.
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'Attachm:nt W3F1-97-0174 Page 2 of 3 4
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Upon a Safety Injection Actuation Signal (SlAS)in response to a loss of reactor coolant (LOCA) or main steam line break (MSLB) accident, the CC-200B valve closes to isolate the two trains while allowing continued cooling of some non-a I
essential heat loads. Upon a Containment Spray Actuation Signal (CSAS)in 4'
conjunction with an SIAS, both CC-200A and CC-200B valves close to isolate the j
two trains and to shed all non-essential heat loads.
The limit for the monitors' sample temperature is 130 degrees F. The tap for the l
cooling water for the 'A' monitor sample heat exchanger is located outside CC-200A l
.va ve and is therefore neither isolated nor cross-connected with the 'B' train when j
i either or both header isolation valves are closed. However, the tap for the 'B' i
monitor cooling water is between the two header isolation valves. This location provides the path for cross-connection from the 'A' train to the 'B' train when CC-l 200B closes with an SIAS only, it is also isolated from flow when both CC-200A and
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CC-200B close with a CSAS in conjunction with an SIAS.
When this limitation was discovered, Waterford 3 Operations personnel conservatively declared the 'B' monitor inoperable and isolated it to prevent any cross-connection potential. As required by TS 3.3.3.1, Table 3.3-6, ACTION 28, Chemistry personnel began taking grab samples of CCW once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and analyzing them for gross activity within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Causal Factors This design flaw has existed since the plant was built. It cannot be determined with certainty if there was a reason for this apparent oversight because of the lapse of time and personnelinvolved.
Corrective Measures To restore CCW radiation monitor 'B' to operable status, design change DC-3537 has been approved to reroute the cooling water line from its current connection point between the CC-200A and CC-200B header valves to the 'B' train side of the CC-200B valve (similar to the current train 'A' configuration). Continuation of modification work related to DC-3537 after June 12,1997 has resulted in radiation monitor 'B' remaining inoperable beyond 30 days, resulting in the requirement for this Special Report in accordance with TS 3.3.3.1, Table 3.3-6, ACTION 28.
i Required grab samples from the CCW will continue to be taken by Chemistry personnel while testing and visual examination is completed in accordance with flow j
requirements. After completion of required testing, CCW radiation monitor 'B' will be i
returned to operable status.
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Att:chmsnt l'
W3F1-97-0174 Page 3 of 3 Safety Significance The CCW radiation monitors provide no safety function under accident conditions.
1 The Waterford 3 Safety Analysis Report and the TS list them as process monitors.
Their monitoring function is not taken credit for in post-LOCA/MSLB safety analyses nor do they directly control the release of radioactive material. Their isolation under
- these conditions is not significant.
l The concern with cross-connection is the loss of cooling water from the 'A' train through the CC-200A header valve and the 'B' monitor sample cooling line to the 'B' train. A low water level in the CCW surge tank is indicative of a leak in the system and interlocks isolate the two CCW trains and line up the pumps for the healthy train.
Therefore a cross-connection would result in isolation, which, as described above, is 4
i not significant under accident conditions.
1 While the monitors provide no safety function, their continued reliable operation
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under all conditions is desirable. Therefore the modification described above was.
i implemented.for this purpose.
Similar Events A review of Waterford 3 Licensee Event Reports submitted since 1995 identified no E
similar instances where a design discrepancy could cause a cross-connection l
between trains and/or an isolation of a component.
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