ML20210C384
| ML20210C384 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 01/27/1987 |
| From: | Carey J DUQUESNE LIGHT CO. |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| REF-PT21-87-074-000 2NRC-7-016, 2NRC-7-16, 85-03, 85-3, PT21-87-074-000, PT21-87-74, NUDOCS 8702090377 | |
| Download: ML20210C384 (3) | |
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2NRC-7-016 (412) 6415200 Beaver Valley No. 2 Unit Project Organization Telecopy (412) 6415200 Ext.160 S.E.G. Building P.O. Box 328 Shippingport, PA 15077 January 27, 1987 s
United States Nuclear Regulatory Connission Region I
'631 Park Avenue King of Prussia, PA 19406
' ATTENTION: Dr. Thomas E. Murley Aontinistrator.
s
SUBJECT:
Beaver Valley Power Sta. tion - Unit No. 2 Docket No. 50-412 Equipnent Qualification of. Lore Exit Thennocouple Systen Potential Significant Deficiency Report 85-03 Final Report
REFERENCE:
1.
Westinghouse Letter DMW-D-5633; 8/28/86; Accuracy Requirenent Evaluation for Inadequate Core Cooling Instrumentation s
2.
Westinghouse Letter DMW-D-5623; 8/29/86; BVPS-2 Emergency Operating Procedures Gentlemen:
This is the Final Report in reference to the Equipners Qualification
(. ' Core Exit Thennocouple Systen as reported to the NRC by Mr. S. D. Hall of Duquesne Light Compan) on May JA, 1985.
Westinghopea has canpleted their evaMycr. Li ag < < -,.
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with reconmenaed corrective action:
Pursuant to th 1.quirenents of 10CFR50.5> M,
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K, c rts wi11 be ch airs,
DUQUESNE LI T COMPANY
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By Sr. Mce. Carey f
(/J/4 President LMR/ ij r NRC/LMR/SDR/8503 Attactinent AR/NAR cc: Mr. P. Tam, Project Manager (w/a)
Mr. J. M. Taylor, Director (3) (w/a)
Mr. J. Beall, Sr. Resident Inspector (w/a)
Ms. A. Asars, NRC Resident Inspector (w/a)
INP0 Records Center (w/a)
NRC Document Control Desk (w/a) 8702090377 870127 g
PDR ADOCK 05000412 S
PDR g,
Attachnent 1.
Suninary Whghouse (W) ituclear Safety Department reports that, during the course of Environnental Qualification (EQ) testing, potential errors in excess of those previously assuned were discovered in the safety grade core exit thermocouple systen.
-W reports that this type systen has been supplied to Beaver Valley Power Station Unit No. 2 (BVPS-2).
2.
Immediate Action Taken W had reported this concern, under 10CFR21, to the NRC on May 9,1985.
En May 10, 1985, after receipt of a copy of the W 10CFR21 report, Mr.
S. D. Hall, acting manager of Duquesne Light CodIpany's (DLC) Regula-tory Aff airs Department, notified Mr. Lowell Tripp at the NRC's Region I office, that DLC considered this concern to be potentially report-able in accordance with 10CFR50.55(e).
3.
Description of Deficiency During Ey testing, W detennined that total core exit thennocouple systen errors could exceed previously assaned values during High Ener-gy Line Break (HELB) conditions.
W reports that the signal would renain functional in spite of total systen errors larger than those on which the W Emergency Response Guidelines were based.
4.
Analysis of Safety Implications Potential consequences of exceeding the assumed tenperature cnannel accuracy requirenents include the following:
(1) delay in tenninating SI following a secondary high energy line rupture or small-LOCA which could potentially result in water relief through the pressurizer safe-ty and/or relief valves; (2) inappropriate SI tennination following a small LOCA necessitating operator action to reinitiate SI; and (3) f ailure of the operator to trip the RCPs following a small LOCA if i
subcooling margin is utilized as the criterien.
Occurrence of any of the above consequences due to increased tenpera-ture uncertainty in the RCS subcooling margin could result in conse-quences more severe tr.cn currently described in the Final Safety Analysis Report (FSAR) accident analyses.
5.
Correci.ive Action to Resolve the Deficiency Based on the Wc tinchcuse final evaluation report (Ref.1), the following changes have been made at BVPS-2:
a.
The Reactor Vessel Level Indication Systen (RVLIS) tenperature input has been changed fran core exit thennoccuples (CET's) to loop resistance temperature detectors (RTD's).
b.
The Inadequate Core Cooling (ICC) setpoint of 700*F has been
{
increased to 729'F to incorporate actual worse case post-accidant i
errors of the CETs- (which functions as a tenperature reading only, not an-input to RVLIS).
This change was made in Emergency Operating Procedures ES-0.4, ES-1.4, ES-3.3, ECA-2.1, ECA-3.1, ECA-3.2, ECA-3.3, F-0.2, FR-C.1, and FR-C.2.
c.
The CET revised systen accuracy has also been incorporated into the Emergency Operating Procedures.
CET error above 1000 psig is
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less than 50*F; between 400 psig and 1000 psig, tne CET error is less than 60*F.
These accuracies are acceptable for performing the operator actions necessary in the Emergency Response Guide-lines.
The CET accuracies have Deen used in the detennination of new setpoints and the following have been revised to reflect these new setpoints:
E-0, E-1, E-3, ES-0.1, ES-0.3, ES-0.4, ES-1.1, ES-1.2, ES-1.4, ES-3.1, ES-3.2, ES-3.3, ECA-0.0, ECA-0.1, ECA-2.1, ECA-3.1, ECA-3.2, ECA-3.3, FR-P.1, FR-I.3 and F-0.2 6.
Additional Reports No additional reports are expected.
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