ML20117N004
| ML20117N004 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Palisades |
| Issue date: | 03/13/1984 |
| From: | Paul Klein CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Keating D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20114G054 | List:
|
| References | |
| FOIA-84-616 PJK-15-84, NUDOCS 8505170349 | |
| Download: ML20117N004 (1) | |
Text
I OW Power
/d CORSum8m Company General offices: 1945 West Parnell Road, Jackson, MI 49201 e ($171788-oS50 March 13, 1984 PJK 15-84 6
Mr Dale Keating NRC Region III 799 Roosevelt Road Glen Ellyn, IL 60137 The sixth inspection of the Palisades SIRW tank support structure was per-formed on March 12, 1984 at the request of Palisades personnel with the tank 18% full.
This inspection follows an inspection on March 8, 1984 with the tank empty.
Since the March 8 inspection, the tank has been loaded to approximately 75% of its capacity and then reduced to 18% of its capacity. The results of the March 12, 1984 inspection show no significant change in elevation of the tank support structure..Due torthe shortlduraticarof the reload and the volume of the tank during relo'ad and~during the inspection, this inspection will be~used-
.for information only. 1No comparisons or. conclusions'will be made.
Further inspections will be conducted during the current refueling outage to establish the structural behavior of the tank support structure.
A 5
Paul J Klein Senior Engineer 1945 W Parnall Rd, Rm P-24-114 CC Bruce Jorgenson, NRC (Palisades)
BDJohnson, P-24-606 DJVandeWalle, P-24-614B ERCooper, P-24-306 KKChao, P-24-304 DCC: 950/00211/01400 8505170349 840914 PDR FOIA BARFIELB4-616 PDR OC0384-0143A-NS06 g gg3
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March 15, 1984 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C.
20555
Dear Sir:
Reportable Occurrence Report #84-012-00, Docket '/05'0-373 is being sub-mitted to your office in accordance with 10 CFR 50.73 J. Diederich
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,--. - - ~ ~ n, On Feb. 14, 1984 with Unit One shutdown. Locak Leak Rate Tests were performed, it was cetermined that the Technical Specification 3 6.1.2 l imi t of.6La was exceeded.
The leaking valves were:
1E21-F010A, 1HG001A/2A, 1HG005B/6E, and 1RE024/25 The feecnater check valve Icekace was a result of a misalignment problem which pre-ventec the disc from closing scuerely against the seat.
Visual instections of the soft seal material showed it to be in good condition. The HG valve seats showed some slight pitting, pcssibly a result of concensation/cxication in the line.
The RE valve seats were worn sligntly wi th minute grooves worn into the valve discs.
Some debris was also found in the line.
The FV check valve was worked on to correct the misalignment problem.
The hinge The HG pins were mechined to equalize side clearances and eliminate sice shi f ts.
volve seats and discs were lapped to remove the pitted surfaces.
The RE valve discs w2re machined to remove the small grooves and all debris was removed.
Acceptable Leak Rate Tests were performed on all valves.
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EVENT DESCRIPTION:
On Feb. 14,.1984, with Unit One shutdown for a planned outage, type B6C Local it was determined that the Technical Specification
- Leak Rate Tests were performed, 3 6.1.2 limit of 0.6La (231.4 SCFH) was exceeded.
leaking in excess of procedural gu,idelines:
- 1) IB21-The following valves were (SJ) Check Valve 2) 1HG001A/2A, Combustible Gas Control F010A, inboard Feedwater (BB) Suction Valves 3) 1HG0055/65, Combustible Gas Control Return Valves 4) 1RE024/
25, Drywell Equipment Drain (WK) Sump Valves.
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CAUSE:
Inboard Feed ater Check Valve Leakage.was a result of a misalignment problem The the seat. The disc was which prevented the disc from cicsing squarely againstwhich left a maximum.058' gap found to be off centered slightly from the body seatinspections of the sof t seal Visual be tween the "Sof t Seal" and the body seat.
material previously installed in Nov. 1983, showed i t to be in good condition 3
with no defects.
r Gas Control Valve Seats sho*ed sore slight pitting, possibly a
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I L The combus t i b le oxidation in the line.
h re sul t of condensat ion anc s ubsequent Drain succ valve seats were worn slightly with minute grooves The Drywell Ecul p: rent line (i.e.,
There was also some debris founc in the into the valve ciscs.
tape, wire, etc.) but it is not known if this contributed to the leakage.
worn Ill.
FROBABLE CONSEQUENCES:
inbcard Feecwater Check Valves woulc have prevented a It is believe,d Inat the significant loss of vessel i nven t o ry in the event cf a feed. ster line break.
In in each line which lines still have twc isolation valves the f e e c,.a t e r iso-accition, recui rements of Appendix J to 10 CFR 50 criteria as containment meet the lation valves.
Drain Sump Valves The C ombustible Gas Cont rol Valves and the Drywell EquipmentThey are positi isolation valves.
leakage. The are double lines, thereby minimizing the potential for excessive containmentisolation valves is Combus t ible Gas Cont rol Sys tem downs tream of the subj ectin accordance with Technica periodically verified to be leak tightDrain Sure lines would ncrmally be water filled which would The Drywell Equipment These valves, however, are tested wi th ai r whi ch is a limit cont ai nre nt leakage.
nore censervat i ve reasure.
the believed that no iramediate safety hazarcs existed, and that It is therefore all times.
plant was maintained in a safe condition at g
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CORRECTIVE ACTION:
the misallpnment Action was taken on the feedwater check valves to correctTh cle a rasnces and eliminate the recurring side shifts.
Adcete nal problem.
Corrective Actions being taken are outlined in a confirm lette' (NRC) to C. Reed (Ceco).
dated 11/28/83 from J. Keppler t r.e pi tted The Combustible Gas Control Valve seats an'd discs wer c 5.atis-surfaces.
factorily on 2/28/84.
11 Drain Sump Valve Discs were machired to rerreve the str.a d cat,s-s The valves were reassembled and Leak Rate Tests were performe The Drywell Equipment line.
f actorily on 3/5/84.
All debris was removed f rom the crooves.
V-PREVIOUS OCCURP.ENCE:
ig3 See.
took place on November 9,1983 and September 1, Similar occurrences LER Numbers 83-1Lb/C3L-0 and 83-107/03L-0.
NAME AND TELEPHONE NU.wEER OF THE FREPARER:
Randy 5.
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, MEMORANDUM FOR:
Victor Stallo, Jr., Deputy Executive Director for Regional Operations and Generic Requirements FROM:
Richard C. DeYoung, Director Office of Inspection and Enforcement SU8 JECT:
REQUEST FOR CRGR REVIEW OF PROPOSED IE BULLETIN 84-XX:
UNDERVOLTAGE TRIP ATTACHMENTS OF REACTOR TRIP BREAKERS Please schedule a CRGR review of the proposed subject bulletin (Enclosure 1).
This bulletin is considered to be a Priority B item as specified in the CRGR charter. We suggest a CRGR meeting during the week of March 26, 1984.
A previous draft of the bulletin (Enclosure 2) was issued on January 9,1984 for in-house, Institute of Nuclear Power Operations, Atomic Industrial Forum, and the Babcock & Wilcox, combustion Engineering, and Westinghouse Regulatory Response Groups' comments.
The present version of the bulletin reflects comments received froar the responding in-house sources and the aforementioned industrial organizations (Enclosure 3).
The proposed bulletin requests licensees using undervoltage trip attachments (UVTAs) ori their reactor trip breakers (RTBs) to:
(1) periodically test the UVTA function for RTB OPERA 8ILITY and to infore the NRC of any failures result-ing from these testsi (2) inform the NRC of their procedures for testing the UVTA function, their plant's time response (or other operability parameter) criterion for the UVTA function; and (3) provide written instructions to their plant's operating staff regarding our interia definition regarding RTB OPERA 8ILITY, actions to be taken when one or more RTBs are INOPERABLE, and reporting requirements when one or more RTBs are found to be INOPERABLE.
Based on the actions requested of affected licensees in the proposed bulletin, we estimate the per plant burden te licensees to be:
PROFESSIONAL PERSON-HOURS PER PLANT PROFESSIONAL NON-PROF.
NON-PROF. '
(RESEARCH, COST PER PERSON-HRS.
COST PER REPORT PLANT @
PER" PLANT PLANT 9 PREP. AND
$60 PER HR.
(TESTING AND
$30 PER HR.
TOTAL COST PROCEDURES)
REPORTS)
PER PLANT 32
$1,920 120
$3,600
$5,520 n d M n c..
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Since fifty (50) plants are affected by this bulletin, the estimated total cost associated with responding to the bulletin is $276,000.
"Originsi Signed By v c. c. : :- e Richard C. DeYoung, Director Office of Inspection and Enforcement Technical
Contact:
I. Villaiva
Enclosures:
1.
Proposed IE Bulletin 2.
Previous Draft of IE Bulletin 3.
Comments on Previous Oraft Bulletin cc:
w/ enclosures H. R. Denton, NRR D. G. Eisenhut, NRR G. Holahan, NRR J. G. Partlow, IE C. E. Rossi, IE I. Vi11alva, IE W. Schwink, E00 (10 copies)
Distribution:
OCS EAB File DEPER File RCDeYoung JMTaylor ELJordan SASchwartz (CERossi IVillaiva
- SEE PREVIOUS WHITE FOR C0ilCURREitCES
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- DEPER:IE
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,e SSIN No.:
6835 ENCLOSURE 1
-OMB No.:
3150-00012 Expiration Date:
IEB 84-UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 1984 IE BULLETIN NO. 84-UNDERVOLTAGE TRIP ATTACHMENTS OF REACTOR TRIP BREAKERS
. Addressees:
All pressurized water reactor (PWR) power facilities holding an operating
-license (0L) for action except Yankee Rowe, Fort Calhoun and Palisades; all other nuclear. power facilities for infonnation.
Purpose:
- The purposes of this bulletin are:
(a) to assure that licensees are perfonning adequate testing of the reactor trip breakers (RTBs), (b) to clarify the "0PERABILITY" requirements related to RTBs, and (c) to collect information needed for. future staff decisions related to the need for improving the reliability of.the UVTAs.
Description of Circumstances-
. The-NRC staff has recently become aware of approximately 24 instances at six facilities where the undervoltage trip attachments (UVTAs) failed to trip GE Type AK-2-25 RTBs within the acceptance time specified by the licensees. These failures occurred subsequent to actions initiated by licensees in response to IE Bulletin 83-04 and Generic Letter 83-28.
In some instances, the UVTAs did not trip their associated RTBs at all.
There have been a' number of instances i
where multiple RTB failures were found.
On two separate occasions, all eight i
of the UVTAs used in a Combustion Engineering-designed plant failed to trip their associated RTBs within the acceptance time specified by the licensee.
Background:
As a result of the February 22 and 25,1983 Salem anticipated transients without scram (ATWS) events, the NRC issued IE Bulletin 83-01 and fonned a task force to assess the generic implications of these events.
On March 11, 1983, Southern California Edison reported that three RTBs on San Onofre Unit 2 l _
and one on Unit 3 failed to open during testing of the UVTA.
As a result of L
these failures, the NRC. issued IE Bulletin 83-04.
-The task force's actions resulted-in the issuance of NUREG-1000, " Generic l'
Implications.of ths ATWS Events at the Salem Nuclear Power Plant" and Generic L
Letter 83-28, delineating the procedural and plant changes required.
Findings in NUREG-1000 were based, in part, on assurances that improved maintenance of the breakers being reconinended by the manufacturers would improve the reliabil-ity of the UVTAs to an acceptable' level for the short term, after which the-i
..n
- s.
e IEB 84-
, 1984 Page 2 of 5 longer term corrective actions would be implemented.
Based on the recent number:of failures experienced with GE AK-2-25 type breakers, it now appears that an acceptable reliability is not.being attained at all plants.
A partic-ular concern is.that many of the failures occurred after the breakers were
. reportedly maintained per GE's latest recommendati~ns.
The NRC staff, there-o fore, is concerned that. maintenance alone may not be effective in providing reliable performance of GE AK 2-25 RTBs on a. continuing, basis.
In view of the existing small design margin of the UVTA regarding forces available versus those required to actuate the breaker,.a design improvement may be necessary to achieve-the long-term high reliability required for reactor trip systems.
Nevertheless, licensees are expected ~to continue to emphasize preventive-maintenance to assure high breaker reliability.
Toward the same end, the NRC will continue to scrutinize any ensuing RTB malfunction in order to preclude an ATWS event.
During one recent instance, all the RTBs failed to open within the acceptance time specified by the licensee; however, the plant was operated at 100% power for a brief period of time.
The licensee believed that since the shunt trip devices in the RTBs were functional, the RTBs should be considered "0PERABLE."
The NRC staff does not agree with this approach and accordingly has developed
'the interim guidance given later in this bulletin.
Said guidance is to be used until such time as the relevant issues of Generic Letter 83-28 are resolved.
In view of recent operating experiences, the NRC established a special review team to determine which (if any) actions in Generic Letter 83-28 involving GE AK-2-25 RTBs need to be accelerated or changed.
Certain information being solicited by this bulletin will facilitate the staff's final decisions on these matters.
In addition, because of the uncertainties involving the manner by which the Westinghouse RTBs are being tested and whether any such RTBs have failed to open per their OPERABILITY criterion in 1983, especially in view of the lack of an automatic shunt trip in most Westinghouse designed. plants, Westinghouse designed plants are also included in this bulletin.
During recent meetings with the staff, both the Combustion Engineering and the Babcock & Wilcox owners' Regulatory Response Groups stated that diverse reactor trip features (shunt trip and silicon controlled rectifiers) are currently being tested on a periodic basis at each plant.
Such' tests, coupled
-with the tests requested by this bulletin, will ensure that'the~ capability of
-reactor trip is closely monitored pending completion of long-term actions to
' mprove reactor trip system reliability.
i The actions being requested by thT' bulletin shall remain in force until the
~
s relevant issues in Generic Letter 83-28 are resolved or for twelve (12) months from the date of this bulletin, which ever occurs first.
r i
b
_ = _ _
i.
s IEB 84-
, 1984 Page 3 of 5
' Required Actions for PWR-Facilities Holding Operating Licenses (Except Yankee Rowe, Fort Calhoun and Palisades):
1.
Performance tests of the UVTA function of each in-service RTB shall be initiated within 30. days.of receipt of this bulletin.
Response time tests are the preferred performance tests for plants using GE RTBs.
Licensees using Westinghouse RTBs may find that other parameters such as drop-out voltage are better indicators of an INOPERABLE RTB than response time.
In either case, licensees may propose alternatives to response time as the performance tests.
In such cases, licensees shall provide the bases _for selecting the alternative parameters.
The tests shall be conducted monthly until each breaker successfully c
passes two consecutive monthly _ tests, after which the test frequency may be relaxed to a two month interval.
If a breaker fails to pass its performance _ test during the two month testing interval, maintenance should be performed and the surveillance testing shall be returned to a monthly interval.
Performance tests shall be conducted independent of shunt trip, if applicable, and prior to any maintenance, adjustment or functional tests.
' Testing should be conducted to the maximum degree practicable with the
' RTBs in their cubicles, provided such testing does not jeopardize personnel or plant safety, and prior to any operation that would trip the RTBs.
The use of lifted leads or jumpers is to be minimized.
. Performance tests may be conducted on a staggered basis provided that each in-service breaker is tested during the test interval described above.
P.lants for which on-line testability is not provided (i.e.,
[
plants whose RTBs cannot be tested without tripping the reactor) shall perform these tests prior to resuming operation or if currently operating,
(
during the next plant shutdown.
2i Provide the 'following information:
(a) A brief, description of the performance tests being used to verify the. operability of the UVTA including the accuracy of the test equipment, and RTB location during the tests (e.g., in-situ, bench).
J (b) An explicit OPERABILITY criterion for the UVTA performance parameter l
_(e.g., response time, drop-out voltage) of the RTB based upon the l
current licensing basis for the plant.
This criterion should conservatively-account f6r the instrument accuracies stipulated in item 2 (a), above.
(Note:
Based upon information provided to the NRC, we believe the response time criterion should be in the 100 L
millisecond range.for Combustion Engineering and Babcock & Wilcox designed plants.)
(c) Plants are requested to report the failure of any RTB to respond r
L within its UVTA OPERABILITY criterion or other failure during the calendar year of 1983, including the date of the failure.
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IEB 84-
~
, 1984 3.
Page 4 of 5 1.
3.
Provide written instructions to the plant's operating staff requiring that:
.(a) A reactor trip breaker shall be considered INOPERABLE if its UVTA performance parameter.does not meet the OPERABILITY criterion.
(b)
INOPERA8LE RTBs shall be treated in accordance with the plant's technical-specification regarding RTBs.
In the absence of such a technical. specification INOPERABLE RTBs shall be either placed in the tripped position or removed so as to interrupt current flow within four hours except where such actions would result in a reactor trip.
Where such actions would result in a reactor trip, an orderly shutdown of the plant should be initiated within one hour such that HOT STANDBY (i.e., Keff 5.99, Tav 1 NO-LOAD Tav) is attained within six hours.
(c) The NRC.shall be notified via the Emergency Notification System (ENS) of any RTB becoming inoperable, regardless of whether the failure occurred during in-situ or bench testing or the operating mode c/ the reactor.
RTB failures shall be reported via the ENS.within foce hours unless the number and/or locations of the failed RTBs warrant reporting under 10 CFR 50.72 on an accelerated basis.
Should a licensee determine that any actions requested by this bulletin jeopardizes.overall plant safety, the NRC should be notified of that fact and provided with appropriate justification for not implementing the requested action.
Such notification shall be made within 30 days of the date of this-bulletin in accordance with the notification instructions of this bulletin.
A written response addressing each of the items inc'luding results of the first monthly test shall be submitted within 60 days of the receipt of this bulletin to the appropriate Regional Administrator under oath or affirmation under provisions of Section 182a, Atomic Energy Act of 1954, as amended.
The original of the letter and a copy of any-attachments shal1 be transmitted to the U. S.
Nuclear Regulatory Commission, Document Control Desk, Washington, D. C 20555
-for reproduction and distribution.
Subsequent letter reports shall only be
-submitted following a RTB failing to meet its OPERABILITY criterion.
Such reports shall~be made.within 30 days.of the malfunction and in accordance with the procedure for the original. letter reports.
These letter reports shall identify.
-the INOPERABLE breaker, its deviation from the OPERABILITY criterion, remedial
. actions taken, and the results.of said actions.
- - -, - +
+
o
-o This request for information was ' approved by the Offi Budget under a blanket clearance number 3150-0011, wi 1985.
Comments on burden and duplication may be dirG Management and Budget, Reports Management, Room-3208, Building, Washington,'D. C.
20503.
Richard C. DG Office of Ins 9
Technical Contacts:
I. Vi11alva, IE J. T. Beard, (301) 492-9635 (301) 492-7461
Attachment:
List of Recently Issued IE Bulletins m
ENCLOSURE 2 c,,
^
SSIN No.:
6835 OM8 No.:
3150-00012.
Expiration Date:
IEB 84-UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 January.
, 1984 IE BULLETIN NO. 84-UNDERVOLTAGE TRIP ATTACHMENTS OF REACTOR TRIP BREAKERS Addressees:
All pressurized water reactor (PWR) power facilities holding an operating license (OL) except Yankee Rowe, Fort Calhoun and Palisades for action; all other nuclear power facilities for information.
Purpose:
The purposes of~this bulletin are:
(a) to assure that licensees are performi'ng adequate testing of the reactor trip breakers (RTBs), (b) to clarify the
" Operability" requirements related to RTBs, and (c) to collect information needed for future actions related to NRC Generic Letter 83-28.
Description of Circumstances The NRC staff has recently become aware of approximately 24 instances at six facilities where the undervoltage trip attachments (UVTAs) failed to trip GE Type AK-2-25 RTBs within the acceptance time specified by the licensees.
In some instances,-the UVTAs did not trip their associated RTBs at all.
There 4
have been a number of instances where multiple RTB failures were found.
On two separate occasions, all eight of the UVTAs used in a Combustion Engineering-designed plant. failed to trip their associated RTBs within the acceptance time specified by the licensee.
Background:
As a result of the Salem anticipated transients without scram (ATWS) events and multiple RTS failures at San Onofre, the NRC issued IE Bulletins 83-01 and 83-04.
A task force was formed to assess the generic implications of these events.
The task force's actions resulted in the issuance of NUREG-1000,
" Generic Implications of the ATWS Events.at the Salem Nuclear Power Plant" and
. Generic Letter 83-28, delineating the procedural and plant changes required.
Findings in NUREG-1000 were based, in part, on assurances that improved mainte-
. nance of the breakers being recommended by the manufacturers would' improve the reliability of the UVTAs to an acceptable level for the short term, after which the longer term corrective actions would be implemented.
Based on the recent
g IES 84-January
, 1984 Page 2 of 4 number of failures experienced with GE AK-2.25 type breakers, it now appears that an acceptable reliability is not being attained at all plants.
A particu-lar concern is that many of the failures occurred after the breakers were reportedly maintained per GE's latest recommendations.
In this. regard, it appears that the small design margin of the UVTAs used with GE AK-2-25 RTBs has placed undue emphasis on maintenance and testing of these devices without a commensurate improvement in reliability.
The low design margin of these devices suggests that a major improvement of their operating reliability can.
only be attained by design modifications of the UVTAs.
During one recent instance where all the RTBs had failed to open within the acceptance time specificed by the licensee, the plant continued briefly to operate at 100% power.
The licensee believed that, since the shunt trip devices in the RTBs were functional, the RTBs should be considered "0PERA8LE."
The NRC staff does not agree with this approach and accordingly has developed the guidance given later in this bulletin.
In view of the recent operating experiences, the NRC established a special review team to determine which (if any) actions in Generic Letter 83-28 need to'be accelerated or changed.
Certain information being solicited will facilitate the final decisions on this matter.
During recent meetings with the staff, both the Combustion Engineering owners Regulatory Response Group and the Babcock & Wilcox owners Regulatory Response Group stated that diverse reactor trip features (shunt trip and silicon controlled rectifiers) are currently being tested on a periodic basis at each plant.
This testing, with the testing requested by this. bulletin, will. ensure that the capability of reactor trip is closely monitored pending completion of
-long-term actions to improve reactor trip system reliability.
Required Actions for PWR Facilities Holding Operatina Licenses (Exceot. Yankee Rowe, Fort Calhoun and Palisades):
1.
Perform UVTA-re.sponse time testing of the RTBs and provide the information described below:
(a)
Perform response time testing of the undervoltage trip function on each GE RTB independent of the shunt trip within 10 days of ' receipt of this bulletin unless the UVTA response time of the breaker was tested 30 days or less prior to the date of this bulletin (applies to Combustion Engineering and Babcock & Wilcox des.igned plants only).
.(b) Perform response time tests of the UVTA function on at least a monthly basis, until such time as NRC positions on the responses to sections 3.1, 4.1,-4.2, 4.3, 4.4 and 4.5, as appropriate, of Generic Letter 83-28 are established.
Those plants for which on-
~1ine testability is not provided shall perform these tests prior to resuming operation or if currently operating, during the next plant shutdown.
IES 84-January
, 1984 Page 3 of 4
^
(c) Provide a description of the response time test procedure, including the identification of test' equipment and associated accuracies, and breaker location for the testing (bench or in-situ).
The use of lifted leads or jumpers is to be minimized and, where necessary,
-described in the test procedure.
The test should be conducted prior to any maintenance, adjustments, or functional tests and, where practicable, prior to any operations that would trip the breaker either_ manually or automatically.
(d) Provide an explicit acceptance criterion for the UVTA response time of the RTB based upon the current licensing basis for the plant.
This acceptance criterion.should conservatively account for the instru-ment _accurracies stipulated in item 1 (c), above.
Based upon infor-mation provided to the NRC, we believe this criterion generally should be 100 milliseconds for most plants.
2.
Provide written instructions to the plant staff requiring that:
(a) A reactor trip breaker is not to be considered "0PERA8LE" if its UVTA response time test result exceeds the accept'ance criterion or '
the shunt trip is not functional, where applicable; (b) An "INOPERA8LE" RTB shall be either placed in the tripped position, or removed (to interrupt power flow) within one hour except where this would result in a reactor trip.
Where placing the inoperable RTB in the tripped position (or removing it) would result in a reactor trip, an' orderly shutdown of the plant should be initiated wi' thin one hour such that shutdown is attained within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />; (c) The plant shall not be started up without all RTBs being "0PERABLE";
(d)
A, prompt report shall be made to the NRC via the Emergency Notification System (ENS) of any RTB becoming inoperable, regardless of whether the failure occurs during in-situ or bench testing or the
~
mode in which the reactor is operating.
This prompt reporting requirement shall remain in effect until such time _ as NRC. positions on the _ responses to Generic Letter 83-28 are established.
RT8 failures shall be reported within four hours unless the number and/or locations of the failed RTBs warrants reporting under 10 CFR 50.72 on an accelerated basis.
3.
Provide the date and description of circumstances for any failure of a breaker to respond within its UVTA response time acceptance criterion that has occurred since the responses to IE Bulletins 83-01 or 83-04, as applicable.
4 Describe the measures being ' aken or planned to improve the t
reliability of the RTB UVTAs.
~
IES 84-Jcnuary
, 1984 Page 4 of 4 Except for the results of the monthly tests, a written response addressing each of the items shall be telefaxed to Richard C. DeYoung, Director, Office of Inspection and Enforcement within 30 days of the receipt of this bulletin.**
At the same time, a copy of the response shall be submitted to the appropriate Regional Administrator under oath or affirmation under provisions of Section 182a, Atomic Energy Act of 1954, as amended.
The original of the letter and a copy of any attachments shall be transmitted to the U. S. Nuclear Regulatory Commission, Document Control Desk, Washington, D. C.
20555 for reproduction and distribution.
Letter reports addressing the results of the monthly tests shall be submitted to the appropriate Regional Administrator within 15 days after the completion of the tests.
The original letter' report and a copy of any attachment shall be transmitted to the U.S. Nuclear Regulatory Commission, Occument Control Oesk, Washington, D. C.
20555 for reproduction and distribution.
This request for information was approved by the Office of Management and Budget under a blanket clearance number 3150-00012 which expires April 30, 1985.
Comments on burden'and duplication may be directed to the Office of Management and Budget, Reports Management, Room 3208, New Executive Office Building, Washington, D. C.
20503.
Richard C. DeYoung, Director Office of Inspection and Enforcement
?.
l
- Rapifax (301) 492-8187 or (301) 492-7376 3M Remote Copies (301) 492-7285 or (301) 492-8187 Technical Contacts:
I. Villalva, IE J. T. Beard, NRR (301) 492-9635 (301) 492-7465
Attachment:
List of Recently Issued IE Bulletins i
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ENCLOSIRE 3
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION-e.
h WASHINGTON. D. C. 20S55
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JAN 2 51c84 MEMORANDUM FOR:
Edward L. Jordan, Director Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement FROM:
Darrell G. Eisenhut, Director Division of Licensing Office of Nuclear Reactor Regulation
SUBJECT:
DRAFT IE BULLETIN "UNDERVOLTAGE TRIP ATTACHMENTS OF REACTOR TRIP BREAKERS" We'have reviewed the sub,iect draft Bulletin which you distributed January 9, 1984 Previously, the Division of Licensing provided comments on an earlier draft, by memorandum dated December 29, 1983.
In genera, NRR agrees that _due to rerent operating experience, a Bulletin 1
is appropriate and should be issued as sonn as possible. We also agree that
- the purposes of the Bulletin should be:
to assure proper testing, to clarify
" Operability" requirements, and to gather reliability data to facilitate short term staff review and decisions regarding reactor trip breaker reli-ability pending completion of the longer term review of the licensee responses
NRR comments on the proposed Bulle*in were provided at a meetino between TE and NRR on' January 16, 1984 Agreement _on the folicwing ma,ior items was reached:
1.
Westinghouse plants will be included within the scope of the Bulletin as proposed by IE.
A backaround statement will be added to explain why Westinghouse plants are being included.
The action items will be revised to allow Uestinghouse plants
,to conduct a monthly test other than response time measurement, if such a test.is more appropriate.
2.
The background statements regarding the adequacy of maintenance alone to provide reliable UTVA/RTB performance will be revised to better express this thought as a staff concern rather thar a final conclusion, as it could have been interpreted.
3.
The action items will be revised to recuest failures / demands data so that a quantitative value for recent UVTA/RTB reliability can be estimated.
Contact:
J. T. Beard, ORAB x27465
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JAN 2 51984 Edward L. Jordan -
. 2-NRR will continue to work with IE to finalize the exact wordino of the
-Bulletin.
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ATLANTA. GEORGIA 30303 J A N 181984 MEMORANDUM FOR:
Edward L. Jordan, Director, DEPER, IE FROM:
James P. O'Reilly, Regional Administrator, RII
SUBJECT:
IE ORAFT BULLETIN:
UNDERVOLTAGE TRIP ATTACHMENTS OF REACTOR TRIP BREAKERS Comments solicited by your memorandum dated January 9, 1984, concerning the IE Oraft Bulletin for the GE Type AK-2-25 Reactor Trip Breaker (RTB), were provided to your office by a phone conversation between I. Villaiva and G. M. Nejfelt on January 16, 1984 Comments made by Region II are summarized in enclosure.
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I.k James P. O'Reilly I
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Enclosure:
C'omments provided by Region II cc:
G.'Holahan, NRR R. J. Mattson, NRR J. M. Taylor, IE S. A. Schwartz, IE V. Thomas, IE I. Villaiva, IE CONTACT: 'T. Conlon 242-5537 l
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c ENCLOSURE Comments provided By Region II Concerning IE Oraft Bulletin Forwarded By Jordan's Memorandum of January 9,1984 1)-
It would be more appropriate, if the bulletin was designated as IES 83-01, Supplement 1, since the Westinghouse-05-416 Reactor Trip Breaker (RTB) is not discussed.
~
2)
Item 1(d) - Not all plants in Region II have a licensing basis for the Under Voltage Trip Attachment, (e.g.,
Crystal River 3 measures from signal to rod drop, Turkey point 3 and 4 have none, Oconee 1, 2, & 3 measure RTB responses only during refueling outage).
3)
Item 2(c) - This will provide an undue restriction upon the licensee to operate the plant by requiring that all'RTB spares be operable before the reactor is started up.
4).
Item 4 This is a acot question, since as noted in the draft the problem is one of design; and an increase in testing will not. improve performance of RTBs.
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JAN 181984 -
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MEMORANDUM:
C. E. Rossi, Chief. Events Analysis Branch, Division of Emergency Preparedness and Engineering Response FROM:
Edward G. Greenman, Chief, Projects Branch No.1. Division of Project and Resident Programs, Region I SUIMECT:
REGION I COMMENTS ON DRAFT IE' BULLETIN "UNDERVOLTAGE TRIP ATTACHMENTS OF REACTOR TRIP BREAXERS" The attached comments on the draft IE bulletin concerning Undervoltage Trip Attachments of Reactor Trip Breakers are forwarded for your chastderu.f6rt.
Our r
i-proposed changes have been incorporated directly.
The thrust of our comments is based on field experience at Maine Yankee, Calvert Cliffs, and Millstone Unit 2.
Specifically. Region I feels:
i 1.
Further emphasis should be provided for proper main'tenance and testing of UVTAs until design changes are made.
2.
All breakers should be tested prior to any' breaker 'befrig' rem ~o~yeTto
- - - ~
correct an " inoperable" breaker.
This will. ensure plant shutdown for multiple failures.
Further, all breakers.should be tested in place.
s 3.-
'A clear definition of startup should be provided (e.g., rods withdrawn)'.
This will minimize interpretation by licensees, especially after short-term shutdowns.
4.
Further background information should be provided by licensees on breaker age and any major breaker modifications to properly evaluate data taken during monthly testing.
5.
Only a four-hour report requirement should be imposed. The requirement for an accelerated report, given recent changes to 10 CFR 50.72, is i
confusing and s believe not warranted.
Region I also concur's that this bulletin should apply to all pressurized water reactor power facilities (including Westinghouse).
Please contact Al Luptak (FTS 488-1112) or mysalf should you have additiona1, questions.
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Edward G. Greenman, Chief Projects Branch No. 1 Division of Pr.pject and Resident Programs
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$51N No.t 5435 04 No.:
3150-00012 Empiration Date:
IES 84-UNITED STATES NUCLEAR REGULATORY COIO42$$10N
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OFFICE OF INSPECTION AND ENFORCEMENT WA5HINGTON, D.C.
20555 i
January
. 1984 gg BULLETIN NO. 34- :
LMDERYOLTAGE TRIP ATTACMiENTS OF REACTOR TRIP BREAKER 5 Addressees:
All pressurized Water reactor (PWR) power facilities holding an operating i
license (OL) except Yankee Rows, Fort Calhoun and Palisades f.or.. action 1.all 1
other nuclear power facilities. fee infomation.
1 fJE391RL The purposes of this tviletin ares (a) to assure that. licensees are performing adequate testing of the reactor trip breakers (RT3s), (b) to. clarify the ' '
" Operability" requirements. related to RT3s, and (c) to collect information needed for future actions related to NRC Generic Latter 83-24.
Descriotion of Circumstances
'~~----
The NRC staff has recently become aware of approximately 24 instances at six facilities where. the undervoltage trip attachments (UVfAs) failed to tri Type AK-2-25 RTBs within the acceptance, time specified by the licensees.p GE In same instances, the UVTAs did not trip their associated A7as at all.
There
.' have been a number of instances where multiple RT8 fat. lures-wre found.
On two separate occasions, all eight of the UVTAs used in a combustion i-Engineering-designed plant failed to trip their associated RTBs within the acceptance time specified,by the licensee.
t Backaround:
As e result of the Sales anticipated transients without scram (ATWS) events and multiple RT8 failures at San Onofre, the NRC issued IE Sulletins 83-01 and 83-04. A task force was forined to assess the generic implications of t
these events.
The task force's actions resulted in the issuance.of.NUREG-1000,
" Generic Implications of the ATWS Events at the Sales Nuclear Power Plant" and l
.,-. Generic Letter 83-28, defineating the procedural and plant changes required.
F1hdings in MUREG-1000 wre based, in part, en assurances that improved mainte-1 nance of the breakers being recommended by the manufacturers would improve the
' reliability of the UVTAs to an acceptable level for the short.ters. ayter which
.,i?jhe longer term corrective actions would be implemented.
Based on the recent s I
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Its so-L January
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Page 2,ef 4 number 6f failures experienced with GE AK-t-25 type breakers, it now appears that an acceptable reliability is not being attained at aM A particu-Mdlar concern is that marty of the failures occurred after tha' plants.
breakars were
\\ _reportad1renintained per gE's tatant recommendations.
In this regard, 4t. v e,
. ' appears that the ses11 design margin er the WTAs used with GE AK-2-t$ RT3s has placed undue emphasis en maintenance and testing of these devices without a commensurate improvement in reliability.
The law design margin of these 7
devices suggests that a major improvement af their rating reliability p use, sw men b desi n modifirations. of h6.cm a***,m,ee*w wqr
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During one recent oc=*8ues where all the RTBaAhad failed to open within th*
r' acceptance ties SPacificed by the licensee, the plant continued.
.to operats at 1005 power.
The licensee believed that. since the shunt trlp geyicos. in the RTBs were functional, the RTBs should be considered "0PERABLE.
The NRC staff does not %LWiFwith this approach and accardingly has developed the guidance given later in this bulletin.
?
4 In view of recent operating experiences. the NRC established a special o
review team to determine which (if any) actions in Generic Letter 83-28 need l
to be accelerated er changed.
Certain information being solicited will facilitate the fina1 decisiens on this matter.
3 staF
..During recent meetings. with the staff, both the Combustion Engineering owners %'
Regulatory Response Group and the Babcock & Wilcox ourners Regulatory Response Group stated that diverse reactor trip features (shunt trip and silicon controlled rectifiers) are currently being tested on a periodic basis at each plant.
This testing, with the testing requested by this bulletin, will ensurt.L.
i that the capability of reacter trip is closely.aonitored pending coimpletion.of '
l long-terw actions to improve reactor trip system reliability.
l Recuired Actions for_ PwR Facilities Holdina coeratino Licenses (Except Yan6 fee Rowe. Fort Calhoun and Palisades {:
3 1.
Perform UVTA response time testing of the RT8s. and provide the information *.
described below:
f
- (a) Perform response time testing of the undervoltage trip function on each GE RT8 independent of the shunt trip within 10 days of receipt-of this bulletin unless the UVTA response time of the breaker was 8
tested 30 days or less prior to the date of this bulletin (applies e
to com ustion Engineering and Sabcock & Wilcox designed plants
'. J/,.
enly).'
~,.
(b) Perform response time tests of the WTA function on at least a monthly basis, until such time as. NRC positions en the responses _
to sections 3.1, 4.1, 4.2, 4.3, 4.4. and 4.5, as appropriate of W
.b' Generic Letter 43-2s are established.
Those plants for whib en-
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line testability is not #8SSeece shall perform these tests prior to
.s resuming operation or if curroritly operating, during the next plant
}y shutdown. 'fu*s rnr sua u.
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IEB S4-January, 1984 Pega 3 of 4 sssnis.Eb (c) Provide a%scription of the msponse time test procedura including the identification of test equipment and associated accura,cies, and bmaker location for the testing (bench or in-situ).
The use of lifted leads or jumpers is to be ginimized and, tdiere necessary, described in the test precedure. r A A73.
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(d)- provide an explicit acceptance criterien for the INTA response tlam t
of the RTE based upon the current licensing besta for the plaisit. ~This ecceptance criterion should conservatively account for the instru-ment accurracies stipulated in item 1 (c) above.
Based gen infor 7 4
estion provided to the IstC, we believe this criterion generally should be 100 milliseconds for most plants.
' provide written instructions to the plant staff requiring that:
4 2.
(s)' A reacter trip breaker is not to be considered "0PERA8LE" if its UVTA response time test result exceeds the acceptance criterion se j
the shunt trip is not functional, where applicable; I
lb) An " INOPERABLE" RTs shall be either placed in the tripped position.
or removed (to interrupt power flaw) within one hour esempt where this would result in a reactor trip.
Where RTE in the tripped position (or removing it) placing the inoperable would result in a.
reactor trip, an orderly shutdown of the plant should be initiated aA- -
within one hour such that shutdown is. attained within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />; ihe(Arad*Rahall not be started up4tithout all RT8s being "0PER
<nees nesmera.a*Q m
(c) s-t (d) A Aa Yveport shall be made to the NRC vie the Emergency 1
Notification System (ENS) of any RT8 becoming inoperable, regardless.,
8 of whether the failure occurs during in-situ or bench testing or the '
mode in which the reactor is operating.
This prompt. reporting requirement sha11' remain in effect until.such time as MRC positions on the resoonsas to Generic Letter 83-28,are established.,
3.
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Describe the measures being taken er planned taw taprove the Yh reliability of the RTS INTAs.
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January, iss4 Page 4 of 4.
Except for the results of the monthly tests, a written response addressing each of the itans shall be telefaxed to Richard C. DeYoung, Director Office of Inspection and Enforcement within 30 days of the receipt of this bulletin.**
At the same time, a copy of the response shall be submitted to the appropriate Regional Aministrator under oath or affirmation under provisions of Section 232a,.Atamic Energy Act of 4954, as amended.
The original of the letter and a.
copy of any attachments shall be transmitted to the U. 5.' Muclear Regulatory Commission. Document Control Oesk. Washington, D. C.
205.55 for reproduction and distribution.
Letter reports addressing the results of the monthly tests.
shall be submitted to the appropriate Regional Administrator within 15 days after the completion of the tests.
The-original letter report and a copy of 3
[j.
any attachment shall be transmitted to the U.3. Nuclear Regulatory Commission,,
Document control Desk, Washington, D. C.
20585 for reproduction and s
4,;
distribution.
i 3,
g This. request for information was approved by the Office of Management and
's
'm
{9 tudget under a blanket clearance nueer 3150-00012 which aspires April 30..
.L 1985.
Comments on burden and duplication may be directed ta the Office of Management and Budget, Reports Management. Room 3208, New Executive Office 8vilding, Washington. D. C.
20503; r
Richard C. DeYoung, Director Office of Inspection and Enforcement
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- Rapifax (301) 492-8287 or (302) 492-7378 l
3M Rgeote Copies (301) 492-7285 or (301).492-8187 J
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Technical Contacts:
I. V111alva. IE J. T. Seard, NRR j
.(301) 492-9635
"(301) 492-7465 I..
Attachment:
List of Recently Issued IE Bulletins.
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JAN 131984
...s
-MEMORANDUM FOR:
Edward L. Jordan, Director Division of Emergency Preparedness and Engineering Response, IE FROM:
Thomas A. Ippolito, Deputy Director
- Office for Analysis and Evaluation of Operational Data
SUBJECT:
PROPOSED BULLETIN: UNDERVOLTAGE TRIP ATTACHMENT OF REACTOR TRIP BREAKERS j
'We have reviewed the draft of the proposed bulletin and have the following comments to offer.
j.
- 1. - We note that this proposed bulletin is addressed to all PWR facilities,
- but item 1(a) of " Required Actions..." only applies to GE RTBs.
It is implied in item 1(b) that the perfomance of the UVTA function on a monthly basis is required of all PWR facilities (including Westing-house-designed plants that utilize other than GE RTBs).
This should be made clear in item 1(b).
-2.
Experience has shown us that there is considerable variation in the method of measurement of response time of the UVTA function of the~
RTBs among operating nuclear facilities.
In order to derive a.
common basis for comparing the. response time of the undervoltage trip function, item 1(c) of " Required Actions..." should r'equire ifcensees to provide the definition and detailed method of measure-ment of the response time used in their response time test procedure.
3.
As stated in the " Background".section of the draft bulletin, the operability of the RTBs,.as far as the. staff is concerned, is solely dependent on the proper functioning of the UVTAs.
However, we note p
that in item 2(a) of " Required Actions..." the functional requirement for the shunt trip has been included.
If the intent is to include the operability of diverse reactor trip features (shunt trip and silicon controlled rectifiers), then the bases for including such requirements should be discussed in the " Background" section of the proposed bul1etin.
- 4. - Item 2(b) of " Required Actions..." would a' low continued reactor operation with an INOPERABLE RTB with the RTB either in the tripped position or removed. The required action is silent on plant opera-tions subsequent to tripping or removing the breaker.
Is it intended that the applicable plant technical specifications are governing at this point?
If so, it should be stated; if not, we should tell them what we want.
2-Based on the resolution of these canments we endorse the issuance of the proposed bulletin.
.n"Q&
Thomas A.'Ippolito, Deputy Director Office for Analysis and Evaluation of Operational Data cc:
R. Mattson, NRR
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- 01M/20D 19:24 GMT INPO ATLANTA GA E-56-01184 Institute of i
Nuclear Power Operations 1100 Ctco 75 Parkway Suste 1500 Atlanta, Goo,gia 30339 Tetoonone 404 953-3600 January 20, 1984 Mr. Charles Rossi, Chief Events Analysis Branch Office of Inspection and Enforcement i
U.S. Nuclear Regulatory Commission Washington, D.D.
20555 i
Dear Mr. Rossi:
~
Subject:
Review of IE Draft Bulletin: Undervoltage Trip Attachments of Reactor Trip Breakers Thank you for the opportunity to review the subject IE draft bulletin from INPO's perspective.
We agree that response time testing is an important method of detecting breaker reli-ability degradation and, as such, we have previously addressed (October 10, 1983) this subject in our Significant Ooerating Experience Report 83-8 recommendation number 6: " Routine RTB testing should include measurement of the response time of each breaker.
If degradation of response times is noted, the pre-ventive maintenance program should be revised as appropriate to maintain breaker reliability."
Additionally, ben.ch testing to determine breaker response time may not be a valid indicator of breaker performance in-situ.
Breaker response time testing should be performed in-situ on breakers that have not been recently cycled.
l l
If you wish'. to discuss these comments further, please con-tact me at 404/953-7602 or Don Gillispie at 404/953-7600.
Sincerely, I[
AW' S.L. Rosen, Director Analysis and Engineering Division SLR/ bas cc/wo:
Zack T. Pate Jack W.
Roe T.J. Sullivan l
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ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 UTTLE ROCK, AAKANSAS 72203 (501) 371-4000 January 19, 1984 1CAN018407 Mr. Charles E. Rossi, Chief Events Analysis Branch Division of Emergency Preparedness and Engineer Response Office of Inspection and Enforcement
~
U. S. Nuclear Regulatory Commission
SUBJECT:
B&W Owners Group Comments on Oraft IE Bulletin Gentlemen:
Mr. Richard P. Crouse, Chairman, B&W Regulatory Response Group, forwarded your letter of January 12, 1984, and the enclosed draft IE Bulletin to the ATWS Committee for comment.
As requested by your letter, attached are our comments on the Bulletin.
Only the items on which we had comments are addressed in the attachment.
We wish to express our appreciation for the opportunity to provide our comments and hope you find them responsive to your concerns.
Very truly yours, c2a/^ Lie
- 4. Ted Enos, Chairman 2 BWOG ATWS Committee JTE: si cc:
Mr. R. P. Crouse (TECO)
ATWS Committee NM MEveEsa MiCCLE SCUTw UT:UT'ES SYSTEM
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's; Item 1.(a).
We recommend 'the first response time tests' be conducted within 30 days of receipt of the-Bulletin.
This will allow response time testing to be-
-conducted during regularly scheduled Reactor Protection System Channel
_ Functional testing which is performed monthly.
These tests are normally
~
conducted on a staggered basis with one of the four RPS channels tested each week.
' Item 1.(b)
' _The B&W Owners have responded to Generic Letter 83-28 Items 3.1, 4.1, 4.2 and 4.4 and provided closure to those items.
The Reactor Trip Breaker Reliability Monitoring Program proposed in response to Item 4.2 is an effective means to incorporate response time testing frequencies.
4 m
-y
'Until such time as NRC approves our Item 4.2 program we recommend the o';
- Bulletin incorporate a requirement'as follows.
-Each> Reactor Trip Breaker shall be response time tested on a month 1'y basis until such time as the breaker successfully passes (without modification or maintenance) the response time test.
Upon successfully passing two
. consecutive monthly' tests, the test frequency may be doubled.. Following two
_ successful tests'at the doubled (2 month) interval the test frequency may again be doubled (4 month)
(The doubling may continue, with two successful consecutive tests, until the normal Preventative Maintenance interval (not to exceed 12 months) is reached.
If a brea.ker fails to pass response. time _ testing within one month after PM consideration should be given to replacement.
If a breaker fails to pass response time testing'during testing intervals greater than one month, maintenance should be performed and the surveillance' frequency cut in half.
L
(.
Iten-1.(d)
We. recommend changing " acceptance" criteria to " operability" criteria as this number.will be used to determine operability.
It is generally agreed l
that a more restrictive criterion (e.g. 50 msec) will.be used in procedures as an acceptance criterion and a second value (e.g. 100 msec).used as an operability criterion to determine operability of the breaker.
L
~
Item 2.(a)
Same comment as Item 1.(d)
I 9
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I
. iv Item 2.(c)
We recommend 2.(c) be reworded as follows.
It is believed this rewording is more specific and will~ result in more consistent interpretation.
"The plant shall not be made critical without RTBs being "0PERABLE" as determined at their last regularly scheduled response time test or the most current response time. data available (e.g. response time data was gathered as a result'of a preceding reactor trip).
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Item 2.(d)
We recognize NRC's desire to gather data, in a timely fashion, with regard to RTB failures and are willing to, provide that data.
However, we do not believe that 10CFR50.72 and the ENS is an appropriate medium.to accomplish this notification.
Reports required to be made in 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> could likely f
'j result in' reports being made to NRC by individuals who do not normally
-communicate directly with NRC andiwho may not have access to the scope of information dasired by the NRC.
We recommend, as an alternative, that a. central point of contact be established at NRC and that verbal reports be requested within one normal _
. orking day of the failure.
This will ' allow for more complete reporting of
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.information and by_ a more appropriate level of management.
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^
Item 3'
.Same comment as' Item 1.(d).
4 Written Reports to Rocional Administrators To allow completion'of testing required by Item 1.(a) (30 days) we recommend responses to the Bulletin in 45 to 60 days.
It is likely that response time testing of the RTBs will be conducted as a cart of the RPS Channel Functional Test.
This test is conducted on a stagge. red basis-resulting in all four channels being tested once a month.
We' recommend the written reports be submitted within 15 days after the
~ completion of testing of all 4 channels of RPS (and all associated
-breakers).
However, the staggered testing scheme recommended in our comments to Item 1.(b) could complicate the written reports..A more simple writt'en report' scheme could be as follows:
Provide a written report on the 1st of each month a'ddressing the results.... unless no response time testing has been conducted since the previous-report.
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January 20, 1984 RW-84-07 Mr. Richard C. DeYoung, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555
Dear Mr. DeYoung:
Subj ect: Combustion Engineering Owners Group--Regulatory Response Group, Comments on Draf t I&E Bulletin "Undervoltage Trip Attachments of Reactor Trip Breakers" Recently a draft I&E Bulletin regarding undervoltage trip attachments on reactor trip breakers was distributed for comment.
Since the undervoltage trip attachments were the subject of a December 1983 Combusti.on Engineering Owners Group (CEOG) Regulatory Response Group (RRG) meeting with the NRC, the CE RRG reviewed the draft I&E Bulletin.
Comments based upon the RRG review are provided in the enclosure to this letter.
Should you have any questions on the comments, please feel free to contact me at (203) 665-3614 Very truly yours, b
D I
Rik W. Wells CEOG-RRG RRW/djr Enclosure cc:
J. T. Beard, NRC#
I. Villava, IE s i- ~,
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i Comments on Draft IE Bulletin Undervoltage Trip Attach =ents Item 1 Section--Background (First Paragraph)
Comment-Reference'is made in three instances to "RT3 failures" of the GE AK-2-25 breakers.
The word " failures" should be. modified to more accurately reflect
)
the fact that the b'reakers were, in all cases,' capable of performing their safety function..It is suggested that " failure" be replaced with "undervoltage device performance problems" throughout the background section.
Item 2 t
Section--Background (First Paragraph)
Comment The first sentence implies that IE Bulletin 83-01 was issued partially as a result of the breaker problems at San Onofre. This is not accurate; the sentence should be modified accordingly.
Item 3 Section--Background (First Paragraph)
Comment The first complete sentence at the top of page Z should'be modified to more
~
accurately reflect the current problems with the undervoltage design. The following-wording is suggested for this sentence:
'"A particular concern is that many of the undervoltage devices exceeded the acceptance time specified by individual utilities even after the breakers were reportedly maintained per,GE's latest recommendations."
Item 4 Section--Background (Second Paragraph)
Comment D e to the widespread disagreement and continuing discussions regarding the
- regulatory necessity. for having undervoltage trip attachments, a modification to.the last sentence is. suggested as follows:
"The NRC staff-does not agree with this approach and accordingly has developed the interim guidance given later in the bulletin
,pending final resolution of this issue."
l i
Item 5 Section 1.(a)
Comment It is suggested that the requirement to perform response time testing of the undervoltage trip function within ten days be modified to be within thirty days of receipt of the bulletin. This will enable licensees to perform the response time testing during their regularly scheduled channel functional testing of the reactor protection system.
Channel functional testing is performed on a thirty-day interval.
Item 6-Section 1.(b)
Comment
-The position that undervoltage response time testing should be scheduled and maintained at a monthly interval for plants capable of testing the device at power is unwarranted.
It'is suggested that an appropriate testing' interval for these plants be determined based upon the results of previous testing by the licensee; ks such, the ~ following revision to L.(b) is proposed:
" Perform response time testing of the UVTA function on each reactor trip breaker on a monthly basis until such time as the 9-
-breaker successfully passes-(without modification or maintenance) the response: time test.- Upon successfully passing two,
consecutive monthly tests, the test frequency may be doubled.
Following two successful tests at the doubled (two month) interval, the test frequency may again be doubled (four month).
(The doubling may continue, with two successful consecutive tests, until'che normal Preventative Maintenance interval (not to exceed 12 months} is reached.)
"If a breaker twice fails to pass response time testing with a
-testing interval equal to one month, an engineering evs.luation should be: performed.
If a breaker fails to. pass response time testing with testing intervals greater'than one month,
-maintenance should be performed and the' surveillance frequency cut in half."
b-
. _ ' If the above suggested change is not implemented, as a minimum, continuation of a required monthly testing interval should not be based on an indefinite time period tied to resolving responses'to the generic. letter.
l Item 7 f:
Section 1.(d)
Comment l
It should be noted that in general licensees have two criteria when testing L
undervoltage trip attachment response time. One criterion is a screening criterion which is based on General Electric service information.
This criterioncserves as a guideline for maintenance activities.
The second criterion is an operability criterion and is based on plant specific safety L
analysis.
The breaker is only considered inoperable if the response time l.
fails to' meet-the operability criterion.
No change to this section is suggested..
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= Item 8 Section 2.(a)
Comment For. che same reasons stated in Comment 4, it is suggested that the words "Pending final resolution of the operability issue" be added at the beginning of the sentence.
Item 9 Section ~ 2.'(c)
Comment Section 2.(c) would prevent the plant from starting up if any Reactor Trip Breaker (RTB) is inoperable. This step is unnecessary and unwarranted since Section 2.(b) already requires opening any inoperable RTB (i.e., an inoperable RIB will have performed its safety function in the open position).
There is no safety justification for precluding a plant from starting.up with an open RTB.
As such, it is recommended that Section 2.(c) be deleted.
If Section 2.(c) is not deleted as a result of the comments above, it is suggested that, as a minimum, some clarification is needed. The suggested rewording below is more specific.and will result in more consistent interpretation.
"The plant shall not be made critical without RTBs being
' OPERABLE' as determined at their last regularly schedul'ed response time test."
Item 10.
Section 2.(d)
Comment The need for a " prompt report" of any RTB becoming inoperable is not clear and not considered necessary.
It is suggested that this section be modified as indicated below-l "A verbal report shall be made to the NRC (at a central point of I
contact) of any inservice RTB becoming inoperable, regardic-m of whether... reactor is operating. This reporting requirement shall remain in effect until... NRC positions.
established.
RTB failures shall be reported within one normal working day.unless the number.
^
Item 11 Section--Page 4 (First Paragraph)
Comment The written response to the IE Bulletin is requested within 30 days of receipt
-of.the. bulletin.
Since Comment 5 suggests performing the first response time test within 30 days of receipt of this bulletin, it is suggested that the
~
-written response to the IE Bulletin be required within 60 days after receipt of the bulletin.
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Item 12 Page 4 (First Paragraph)'
Comment The last two sentences refer to. required letter reports addressing results of the response time testing.
Since Section 2.(d) addresses rapid reporting.
requirements cnt inoperable breakers found during testing, the additional
. reporting requirements. listed on page 4 seem redundant and unnecessary.
It is suggested that the last two sentences of this paragraph be deleted.
Should the -above comment not be implemented. it is felt that, as a minimum, some changes are needed to the second to last sentence as follows:
" Letter reports addressing the results of periodic casts shall be submitted _to the appropriate Regional Administrator within 30 days after completion of tests where there were inoperable RT3s."
+
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I CP&L Carolina Power & Light Company OG-ll2 January 19, 1984 Ref:
NRC Letter dated 1/12/84 (Rossi to Goering)
Mr. Charles E. Rossi, Chief Events Analysis Branch Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Dear Mr. Rossii Draft Westinghouse Owners Group Comments to Draft I&E Bulletin on UVTA Time Response Testing Recently, the Westinghouse Owners Group (WOG) was contacted by Messers. E.
Rossi and I. Villaiva of the NRC and informed of a draft Inspection and Enforcement (I&E) Bulletin being developed on the subject of undervoltage trip attachments (UVTA) response time testing. A copy of this draft bulletin was subsequently transmitted to me for WOG review by your referenced letter. The views of the WOG on this' proposed Bulletin follow.
Overall, the WOG does not feel that it is appropriate for the Staff to tie the recent concerns with the GE UVTAs to the Westinghuse designed devices.
The differences in design and force margins have resulted in concerns with UVTA response time that we feel are not a problem with the Westinghouse l
designed UVTAs.
l In addition, the WOG has taken aggressive steps to address all of the concern raised during the past year with Westinghouse designed UVTA performance. Westinghouse and the WOG have had extensive dialogue with the Staff and Connission on the UVTA issue and feel that the concerns with the Westinghouse devices have been adequately addressed. The requirements of this draft bulletin will only tend to reopen issues that we feel have been previously closed.
Our specific connents follow:
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i OG-112 Mr. Charles E. Rossi January 19, 1984 1.
In the Description of Circumstances, the Staff points out that a number. of instances where the UYTA failed to trip GE Type AK-2-25 reactor trip breaker (RTB) have recently been identified. To our knowledge, no additional failures to trip have occurred.on Westinghouse DB-50 or DS-416 RTBs due to malfunctioning UVTAs since the original concerns were identified in early 1983.
2.
Action 1(b) requires response time testing on UVTAs for all PWRs on at least a monthly basis. We feel that this increased testing
. frequency is unnecessary for plants utilizing Westinghouse supplied RTBs since no problem with UVTA time response has ever been identified.
In addition, recent response time tests performed by Westinghouse on several 08-50 and 05-416 UVTAs indicated that excessive trip time is not a problem on these two types of RTBs.
The Westinghouse reactor trip switchgear specifications require that the maximum breaker trip time shall not exceed 167 milliseconds as measured from the time that the UVTA is deenergized. The test-results obtained were well below the maximum a lowable value.
A sumary of the test results are given below:
a.
08-50 UVTA F'or'2'UVTAs operated 2500 times each with. periodic lubrication after every 200 cycles, and response time
. measured (before lubrication) approximately every 200 cycles, the average response times were 78.6 milliseconds (maximum of 93.6 msec, minimum of 70.9 msec) and 77.3 milliseconds (max 88.6, min 73.0 msec).
For i UVTA operated approximately 1700 times without periodic l
lubrication and response time measured approximately every 400 cycles, the average response time was 84.7 milliseconds (max 104.5, min 75.2 msec).
For i UVTA operated 571 times without periodic lubrication, the response time was 68.5' milliseconds.
l-l-
These measurements were made as part of the DB-50 UVTA evaluation program conducted by Westinghouse which were described to the Staff in Westinghouse letter NS-EPR-2824 dated October 5,1983.
b.
DS-416 UVTA l
l For 4 UVTAs operated 2500 times each (with lubrication of the breaker only, after every 600 cycles) and response time measured approximately every 400 cycles, the average response times were 65.2 milliseconds (max 67.5 min 64.3 msec), 55.5 milliseconds (max 59.6, min 53.4 msec),, 53.7 milliseconds j
(max 56.9, min 43.9 msec) and 51.3 milliseconds (max 52.9, min 49.9 msec).
0139c:12
0G-112 Mr. Charles E. Rossi January 19, 1984 These results were obtained from the WOG sponsored DS-416 UVTA cycles life evaluation tests conducted by Westinghouse. This test is approximately fifty percent complete at the present time.
An additional point worth noting on both RTB designs is the larger force margins inherent in the Westinghouse designed devices.
Westinghouse testing has demonstrated.that both 08-50 and DS-416 UVTA designs provide more than adequate force for this application.
For examp'e, recent Westinghouse tests of DB-50 UVTAs demenstrated at least 100% margin in this force ratio. The latest Westinghouse recommendations in this area were established to assure that these devices maintained at least a minimum amount of force margin as e
follows:
For the DB-50, the maximum allowable force required to raise the trip bar and trip the breaker is defined as 31 ounces.
In order to ensure appropriate margin, the latest Westinghouse recommendation requires that the UVTA trip the breaker with
.approximately 20 ounces added to the trip bar as part of the periodic testing of the breaker assembly.
For the DS-416 breaker, the maximum force required to rotate the trip shaft shall.not exceed 2 pounds while the minimum UVTA output shall not be less than 3 pounds.
Based on pa'st Westinghouse field experience and this more recent confidence testing, the WOG believes that imposing monthly response time testing requirements on Westinghouse supplied reactor trip breakers merely accelerates the cyc'ic wear on the switchgear and is not warranted.
3.
Action item 2(b) should be clarified to indicate which mode of plant
' shutdown is required within six hours. The concern here is not to confuse the operator or mandate a mode that would require excessive plant cooldown rates or that would further complicate the plant l
situation after a RTB failure.
4.
Regarding Action 2(d), the applicability of the reporting l
requirements of 10CFR50.7Z is well understood by tie licensees.
However, in the case'af one RTB becoming inoperable which is not currently reportable under 10CFR50.72, a more appropriate l
requirement than the use of the ENS would be a special 14-day period or some other less urgent period which could be instituted in the interim until the NRC review of GL 83-28 responses are completed.
5.
Action 4 specifies that a description be provided of the measures being taken to improve the reliability of the UVTAs. Comprehensive programs for this purpose have been instituted by the WOG; and, the WOG member utilities have provided a description of these measure in responses to Generic 1.etter 83-28. Thus, it is felt inappropriate to reiterate the requirement in the format of an I&E Bulletin.
0139c:12
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0G-112 Mr. Charles E. Rossi 4-January 19, 1984
-In susuary, I would like to emphasize that the WOG and Westinghouse have taken aggressive steps in addressing the industry concerns with Westinghouse designed UVTAs. These actnans include our commitment to cyclic life testing of the DB-50 and D5-416 UVTAs, design and
-installation of the automatic shunt trip actuation circuit, a reliability evaluation of RTB performance and a compilation of the most recent maintenance recommendations for both DB and DS RTBs.
To date, the work completed by the WOG and Westinghouse have only helped to improve the reliability of the RTBs.in our plants. For these reasons we'do not feel that it is necessary for the Staff to increase the response time testing frequency on Westinghouse designed plants.
Furthermore, based on the comprehensive programs undertaken by the WOG designed to address the reliability improvement of the RTBs in Westinghouse plants, we genuinely believe that this Bulletin is not applicable to plants employing Westinghouse RTBs and recommend that it be issued to these plants for information only.
We sincerely appreciate the opportunity to provide our comments; and if you would like to discuss any of these comments further, please do not hesitate to contact me.
Very truly yours,
{)h}
/pab J. J. Sheppard, Chairman Westinghouse Owners Group l
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-February 14, 1984 Mr.-Charles Rossi-Chief,-Events Analysis-Branch Office of Inspection and Enforcement U.S.: Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
IE Draft Bulletin:
Undervoltage Trip Attachments of Reactor Trip Breakers
Dear Mr. Rossi:
This responds to your letter of January 9, 1984, which requested comments on-the subject IE Draft Bulletin.
The AIF Committee on Power. Plant Design, Construction and Operation has reviewed the draf t bulletin and offers-the following comments:
- 1. The need to send-this bulletin to all plants should be reevaluated.
Where there has not been a past history of problems with breaker response time there should not be requirements to do more than what has'been described in utility responses to Generic Letter 83-28.
- 2. It's not clear why these additional testing require-ments should apply to plants with' Westinghouse breakers.
Proper maintenace has already been shown to provide adequate reliability for these breakers.
Also, Westing-house DB-50 and DS-416 breakers do not have built-in capabilities for testing the UVTAs in-situ.
Time testing-of the under~ voltage coils would'have to be done on the bench.
Bypass breakers would have to be racked-in and closed prior to removing the main breakers for bench testing.
This operation carries with it an increased risk for reactor trips and challenge to safety systems.
- 3. The cost to modify the breaker such that it can be tested in-situ is estimated to be no less than $20 K.
It takes ten manhours to conduct the test with the breaker as is.
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- 4. Testing done strictly for reliability determination should be conducted only for a limited period of time, not indefinitely as is indicated by the phrase, "until such time as NRC positions...are established."
For reliability information only, a few plants could be asked to perform the desired testing and collect the data.
- 5. Circuit overall response time is a good indication of system performance.
This test can be done readily with most installations and should be an alternative.
Sincerely, Joseph W. Williams, Jr.
Chairman, Committee on Power Plant Design, Construction and Operation JWW:bif e
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March 11 1934 i
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i Mp' EUBJECT: REEPOESE TO CULTIRMATOET ACTION LL' ITER DATED 11/28/E3 ACTION D-
"EEPORT THE RESULTS OF ALL TESTS AND IESPECTIONS PROMPTLY TO THE ERC RESIDENT INSPECTOR, AND SUBKIT A WRITTEN REPORT OF THESE RESULTS 10 THE REGION III OFFICE WITHIN 14 DAYS OF THEIR OCCUREENCE."
f The 1821-F010A and B Feedwater tilting disc check valves experienced fcrty-four days of unit operation in mode 1,2, or 3 (run, startup, or bot chitdown) since maintenance was performed on the valves in Nove=ber of 1963.
Tha inspection and testing coc:pleted 2/29/84 indicated no soft seat d2 gradation..Etintenance was performed to is. prove the disc to body sett
+
alignment.
The valves were local leat rate tested on 2/17/84 while the unit was in cold shutdown for scheduled testing and maintenance. The corrected type C Icak rate for IB21-F010B was 0.47 scfh. A leak rate for IB21-F0101 could not be determined since t.be test volurne could not be pressucited with air to greater than approximately 10 PSIC. The required test pressure is 39.6 PSIC.
Internsic of both valves were subsequently inspected to verify integrity.
Tha 1821-F010A disc was found not aligned with the body seat. Inst.end, t.be dise was positioned co=pletly to one side with a 0.051 inch cletrcuce bctueen This e hinge pie shoulder and the disc bushing on the opposite side.
(~ isalignment resulted in a 0.058 inch rotzierum cicarsace between the disc soft
-acot and body seat.
Af t.er stnually cycling the disc open three tices, the I
dice co=pletely seated in the body seat..
The as found condition was attributed to the large combined clearance (0.051 inch) between the hinge pin absu1ders end the disc bushings. During unit operations the velve was free to cove horizonttily within t.be 0.051 inch cles.rtnce. After c11 flow through the valve was secured, the disc would swing to the closed position. However, if t.br disc and body. seat were not aligned, the dise would not slide into the 303t due t.o t.be co=hined ef fects of t.he disc to body stat nittlignr.ent End the friction effects between the soft. seat and body scat..
The hinge pin sbculder f
to disc bushing elecrcnces were subsequently reduced to 0.011 inch cnd 0.010 inch (total of 0.021 inch). The velve was retested on 2/25/64 spd the carrected leak rate determined to be B.4 scfh.
it. should be noted t.hr.t sose of the E.8 scfb would be the result of tbc other test. volur.e iscistion vs.1ve 1821-F011A l'ettinf,.
This manual valve is known to lett and is scheduled for
,. nLintenacce at the next pir.nned outage of sufficient Icnsth.
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. gnf. ace.msbla portteca cf th) 1221-F010A OCft cost wero 0100 thtraughly i
eted for any indiectica cf di5endatien. Th2 seft stat appeared anchan ed frosa initici 113 tall: tim la E2ve=bir 1983, l.o., th2ro were no c etace indications and the material exhibited a retlistic elestic property uben prodded with a mets.1 instrument.
The feedwater te=perature and pressure
$,gpear not to have affected the accessible portions of the soft seat.
+
The 1B21-F010B valve internals were inspected on 2/21/B4.
Again, there were no indications of thermal or pressure effects on the soft seat.
- However, 1
th;re were slivers of sof t seat atterial present, soc.e still attached and Gthers separated fross the soft seat.
The slivers were less than 0.001 inch thick a.nd varied in length up to approxicately sir inches.
The slivers originated from the feedwater pump side of the sof t seat immediately adjacent to the disc face. The forration and reroval of the olivers did not affect the sealing capability of the sof t sect.
The presence cf the slivers implies they were formed during the leat rate test pracsuritation of the test volume. The soft seat also erbibited scuff marks c3 cpproximately the botton third.
j These scuff marks were the result of tbt dice being slightly nisaligned with the body seat in the verticci axis.
1.raen th3 test. volume was pressurized, the dise was forced into the cent resulting in the sof t seat scuff rarks. This indication should be considered noretl ecft seat wear and as evidenced by the leak rate results does not affect the f
coaling ceptbility.
In order to minimize the soft sect weer during disc co:prccsion into the body seat, eccentric disc buchings were machined to center the dise with roupect to the body seat. The eccentric bushings' offset wts 0.012 inch.
The hingo pin shoulder to disc buching cletrance was reduced to 0.020 inch cod
">9 inch (total of 0.029 inch) for the same reasons discussed for the
..-F010 h o O M )L. valve. The valve was retected on 2/29/E4 The corrected Icek rcte f-br In conclusion, there were no appcrent environnental ef fects on the sof t coats for the given opereting period. The soft seat indicctions, the silvers and neuff marks, did not affect the setling capability of the valve.
The causa of these indicatione should be eliminated or reduced by the more precise alignment of the disc to body seat, but should not be concidered an abnorcal dagredation of the soft seat. Msintenance on the Unit Two Feedwater Chect valvos 7B2hrn10A-anA n mill sicilarly be perforr,ed to care precisely align
'l th) disc to body seat.
la reference to ite=, D of the subject C. A.L. It hcs been deter =ined by a Lest11e onsit.e review that the succented testing and incpection progrs= bas i
_ beso co=pleted for Ls.Salle Units 1 and 2 based on the following:
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Tho inapecticn rssults cf th2 ccf t cact material during tb3 February outego.
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2.
Th3 prevleus hict:ry cf th3 molded acft osat attorial asperienced at Lasalle Unit 1.
This hist.ory obtained during unit operatior. frc=
August 1982 to September 1983 combined with the inferr.ation obtcined
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during this past unit operation indicates that the type C ler.ksge
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failures occur due to an alignment problem as opposed to failure of the smolded seal.
3.
The experience obtained from other users identified in C. W.
Schroeder letter to J. C. Keppler, dated December 14, 1984, indicated that the soft seat seals, as a minimum, lasted one refueling cycle.
4.
Molded EPR is in place rather than the previously identified vulcanir.ed EPR which experienced failure at the vulcentaed joint in Novenbar 1983.
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5.
As stated in C. W. Schroeder lot.ter to J. C. Keppler dated January 7,.
31, 1984, the schedule to obtain a fully qualified sof t seat material T*
by test is expected to take approximately 10 months. This tir.4 frame would permit reevaluation of the current derign of the rest and implementation of any chaeges during the first refuel of unit one wnich is concistent with muchers 2 and 3 above.
G. J. Diederich l
Superintendent I
LaSalle County Station L
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