ML20106E027
| ML20106E027 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 10/03/1984 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Bishop T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| REF-PT21-84-496-000 ANPP-30733-TDS, DER-84-66, PT21-84-496, PT21-84-496-000, NUDOCS 8410290002 | |
| Download: ML20106E027 (6) | |
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U. S. Nuclear Regulatory Commission Region V; Creekside Oaks Office Park 1450 Maria Lane - Suite 210 Walnut Creek,' Calif ornia 94596-5368 Attention: Mr.' T. W. Bishop, Director Division.of Resident Reactor Projects and Engineering Programs
Subject:
Final Report - DER 84-66 A 50.55(e) Reportable Condition Relating To Downcomer Feedwater Isolation Valve Failed To Close Within Required Time.
File: 84-019-026; D.4.33.2 Ref erence: A) Telephone Conversation between D. Hollenbach and T. Bradish on September 4, 1984
Dear Sir:
Attached is our final written report of the Reportable Deficiency under 10CFR50.55(e), ref erenced above.
Very truly yours, 2ru u c
E. E. Van B runt, J r.
APS Vice President Nuclear Production ANPP Project Director EEVB/TRB/nj Attachment cc: 'See Page Two S
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Mr. T. W. Bishop DER 84-66 Page Two-cc:'
Richard DeYoung,' Director
-Office of Inupection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.
20555 T. G. Woods' Jr.
D. B. Karner W. E. Ide D. B. Fasnacht A. C. Rogers L. A. Souza D.'E. Fowler T. ' D. Shriver C. N. Russo J. -Vo ree s J. R. Bynum J. M. Allen D. Canady_
A. C. Gehr W. J. Stubblefield W. G. Bingham R. L. Patterson R. W. Welcher H. D. Foster D. R. Hawkinson R. P. Zimmerman L. Clyde M. Woods T. J. Bloom D. N. Stover J.-D. Houchen J. E. Kirby
~ Records Center Institute.of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, CA 30339 f
7 FINAL REPORT - DER 84-66 DEFICIENCY EVALUATION 50.55(e)
ARIZONA PUBLIC SERVICE COMPANY (APS)
PVNGS UNITS 1; 2, 3
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. Description of Deficiency CESSAR,. Chapter 5.1.4,Section I.9,.specified a 5-second closing time for. the Downcamer. Feedwater Isolation Valves, and the Final Safety Analysis Report commits to this requirament, which is.necessary to limit the mass of water added to the steam generators following a main steam line break (MSLB) inside the containment. Any water admitted to the steam
. generator during.such;an MSLB will be converted to steam and released-into the containment, -thereby increasing the
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post-accidegt pressure and temperature.
Each dowccomer feedwater line has two adjacent isolation valves in series located outside the containment. Valves.
SGB-UV-130 and SGA-UV-172 provide isolation for steam generator 1.
Valves SGB-UV-135 and SGA-UV-175' provide isolation 'for steam generator 2.
These pneumatically opernted valves close when a main steam isolation signal occurs.
During the startup testing of the feedwater downcomer valves SGB-UV-130,135, SGA-UV-172, and 175 the valves either f ailed to close or closed in excess of the 5-second time limit. When tested for closing individually, valves 130 and 135 did not close and allowed a continued flow of approximately 50% of the test quantity flow of 1,000,000 lbs/hr. When adjacent valves were tested simultaneously, valve 135 closed in 6 seconds and valve 175 several seconds later. Adjacent valves 130 and 172 both closed in 6 seconds. Startup issued NCR SJ-4708 to document this condition.
Evaluation SAR Change Notice No.1200 has been initiated by the Project to revise the closure time for these valves f rom 5 seconds to
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10 seconds. To evaluate the consequences of a similar L
deviation from the CESSAR interf ace requirement for the economizer Feedwater-Isolation Valve (FWIV) closure time of 5 seconds to 10 seconds, as reported in DER 83-80, combustion Engineering (C-E) provided PVNGS-specific mass / energy release
' data for the d3 sign basis main steam line break inside i
containment assuming a 10-second valve closure time (Letters
-V-CE-30008 dated 3/30/84,i V-CE-30051 dated 4/10/84, V-CE-30177 dated 5/1/84, and V-CE-30370 dated 6/11/84). Bechtel l
Engineering performed a containment pressure-temperature j
response analysis using the new data f rom C-E and verified the g~
l following:
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l DER = 84-66.
Page'Two l
a) The containment temperature profile is enveloped by the:
equipment. qualification thermal profile previously establishedhusing generic main steam line break blowdown data f rom CESSAR-F.
' b) The peak containment pressure is also bounded by the existing loss-of-coolant-accident (LOCA) environmental
. qualification ' envelope.
C-E reanalyzed the limiting MSLB with a 10-second FWIV closure time for impact on reactor core thermal-hydraulic response and off-site. radiological. releases (Letter V-CE-30263 dated 3/21/84). Their analysis confirms that a 10-second closure time will not cause a post-trip return to power, and will not significantly affect Lcore protection' or off-site radiological releases.
Combustion Engineering has confirmed that the; analysia performed to evaluate DER 83-80 conditions encompasses a.-
10-second closure time also for the downconer feedwater 4
isolation valves (Letter B/ANPP-E-121754 dated 9/25/84).
This change provides acceptability for the tests where the -
valves are closed simultaneously; however postulating a fail-open condition of one downcomer feedwater isolation valve 4
upon receipt of.a main steam isolation signal', the inability of the adjacent valve to fully close would result in the continuation of feedwater delivery to the steam generator.
This could increase the post-accident pressure and temperature inside containment, representing a significant safety condition.
In order to meet the 10-second closure requirements under all conditioas, Anchor-Darling will retrofit the actuators for the l
12 downcomer feedwater isolation valves listed below:
l Unit l' Unit 2 Unit 3 I
1-J-S GB-UV-130 2-J-SGB-UV-130-3-J-SGB-UV-130 1-J-SGB-UV-135 2-J-SGB-UV-135 3-J-SGB-UV-135 1-J-S GA-UV-172 2-J-SGA-UV-172 3-J-SGA-UV-172 l
1-J-SGA-UV-175 2-J-SGA-UV-175 3-J-SGA-UV-175 Anchor-Darling's review of the deficietcy in closure operation.
l-of the valves indicates they had misinterpreted the closure -
l-requirements stated in 'the specification. The root cause of l
this deficiency is a misinterpretation of the data sheets, which resulted in Anchor-Darling supplying 12 valves within the defined closure time f rame under dynamic conditions following a -line break downstream of the valve.
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J DER 84-661 Page Three o
c In addition to.the feedwater'downcomer isolation-valves listed
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above, the following valves were supplied by. Anchor-Darling to data sheets using a similar format for specifying closure-
. conditions:
Unit 1 Unit 2' Unit 3
.1-J-SGA-UV-500P 2-J-SGA-UV-500P' 3-J-SGA-UV-500P
- J-dGA-UV-500S 2-J-SGA-UV-500S 3-J-SGA-UV-500S-1-J-SGB-UV-500Q 2-J-SGB-UV-500Q 3-J-SGB-UV-500Q:
1-J-SG3-UV-500R
.2-J-SGB-UV-500R J-SGB-UV-500R.
1-J-SGE-UV-169
.~ 2-J-SGE-UV-169 3-J-SGE-UV-169-1-J-SCE-UV-183 2-J-SGE-UV-183 3-J-SGE-UV-183 1-J-SGE-UV-170 2-J-SGE-UV-170 3-J-SGE-UV-170 1-J-SGE-UV-171 2-J-SGE-UV-171 3-J-SGE-UV-171 1-J-SGE-UV-180 2-J-SGE-UV-180 3-J-SGE-UV-180 1-J-SCE-UV-181-2-J-SGE-UV-181 3-J-SGE-UV-181 1-J-SCA-UV-174
'2-J-SGA-UV-174 3-J-SGA-UV-174 1-J-SGA-UV-177 2-J-SGA-UV-177 3-J-SGA-UV-177 1-J-SGB-UV-132 2-J-SGB-UV-132 3-J-SGB-UV-132 1-J-S GB-UV-137 2-J-SGB-UV-137 3-J-SGB-UV-137 4
A design review by Anchor-Darling has concluded that these valves will meet their cloeure requirements.
II.
Analysis of Safety Implications I
Based on the above evaluation, the non-closure of the downcomer feedwater isolation valves constitutes a condition evaluated as reportable under the requirements of 10CFR50.55(e), in that, were this condition to ' remain
-uncorrected it would ' represent a significant safety condition.
The non-closure of the valves is also evaluated'as reportable under 10CFR21.21. This report addresses the reporting requirements of the regulation, with exception of subpart (VI) regarding the number and location of similar components supplied to other facilities.
J III.
Corrective Action Anchor-Darling will redesign the actuators for the 12 downcomer feedwater isolation valves (4 per unit). Design Change Packages 1SM-AF-500, 2SM-AF-500, and 3GM-AF-500 f or Units 1,
- and. 3, respectively, have been initiated to perfois the actuator modifications.
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Mr. = T. W. Bishop DER. ' 84-66 Page Four I
~ NCR No. SJ-4708 will..be final dispositioned following site testing of the' retrofitted actuators at design (dynamic) z conditions.-
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SAR Change-Notice No.1200 has been initiated by the project to revise the closure for the downcomer feedwater isolation valves f rom 5 seconds to 10 seconds. -
' Specification'12-PM-221-B will be conf ormed to reflect the change in the closure times.
. Bechtel Engineering lia's initiated a Bechtel Revision'(BR) to i
the C-E ~interf ace requirement's document, Bechtel Log No.
N001-22;01-9 to reflect the closure time changes.
The actuators are to be modified to close' the valves within the revised specified closure time. The valves will be subsequently site-tested for verification of operational capability., The par'.s necessary to retrofit the actuators are scheduled for delivery and installation prior to fuel load of the respective units.
The final report 'will be transmitted to Anchor Darling in compliance with 10CFR21.
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