ML20099F925
| ML20099F925 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 08/11/1992 |
| From: | Randolph G UNION ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20099F929 | List: |
| References | |
| TAC-M84230, ULNRC-2682, NUDOCS 9208140011 | |
| Download: ML20099F925 (14) | |
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Uv ox E.ur/mc iugust 11. 1992 b
U. S.= Nuclear Regulatory Commission Attn: Doctunent Control Desk
~ Mail Station P1-137-l Washington, D.C.
20555 Centlemen:
ULNRC-2682 TAC No M84230 i
DOCKET NUMBER 50-483 CALLAVAY PLANT EMERCENCY TECilNICAL SPEC 7FICATION CHANCE TO SURVEILLANCE REQUIREMENT 4.3.1.1
Reference:
1.
ULNRC-2681, dated August 10, 1992
' Union Electric Company (UE) herewith transmits an application for emergency amendment to Facility Operating License No.'NPF-30 for Callaway Plant. The change proposes a one time extension to the surveillance interval specified for Technical Specification Surveillance 4.3.1.1, Table 4.3-1, Functional Ur It 1- (Manual Trip). As indicated in Attachment 4, the surveillance of the man _ual reactor trip switch contacts and wiring for the shunt trip and undervoltage trip circuits would be deferred until _the next entry _into Mode
- 3. The Reactor Trip. Breaker and automatic trip circuit surveillance requirements would be unaffected by this amendment.
Reference 1 transmitted a request for Temporary Waiver of Compliance (TWOC) for which oral approval was granted on August 7, 1992.
On August 7, 1992,_during routine review of industry operating experience, Union Electric learned that another licensee with a plant similar to Callaway had requested a TWOC for the same surveillance. Further review of our_ procedures revealed a similar deficiency. The current surveillance procedure used for the manual trip function independently tests the shunt trip and undervoltage trip functions at the breakers, but does not test.the wiring and control room switch contacts for each function, the shunt trip-
- attachment and undervoltage trip attachment, independently. Union Electric notified the NRC on August 7, 1992, that it was likely that a TWOC would be needed.
9208140011 920911 i R ADOCR 0500 3
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I ULNRC 2682 This situation leading to the need for an emergency Technical Specification change could not be avoided since UE acted on the issue luanediately upon discovery.
pursuant to 10CFR50.91(a)(5), UE hereby requests emergency authorization and approval of this proposed amendment. The requested emergency authorization is appropriate because this amendment request involves no significant hazards consideration (Attachment 2). In addition, the present situation could not be avoided as noted above. This emergency Technical Specification amendment is required because this surveillance cannot be fully completed with the plant in Mode 1 or 2 without added risk and without special testing and reconfiguration of the system. The resul*- of the safety evaluation (Attachment 1) show that the reactor trip system remains functional and that the ef fect of deierring the surveillance is
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minimal. There is no adverse ef fect on the health and safety of the public.
The Callaway On Site Review Committee and the Nuclear Safety Review Board have reviewed and approved this request.
In accordance with 10C1R50.91(b), UE will promptly provide the State of Missouri with a copy of this proposed amendment. to ensure their awareness of the request. Uc appreciate your prompt attention to this matter.
Very truly yours, M
, @j Garry L. Randolph CLR/1rj Attachments:
1.
Safety Evaluation 2.
Significant flazards Evaluation 3.
Environmental Consideration 4.
Technical Specification Changes
STATE OF MIS"iOURI )
) SS CALt.Ak'AY COUNTY
)
Garry L. Randolph, of lawful age being first duly sworn up>n oatl.
says that he in Vice Presidant Nuclear and an office of Union Electric Company; that he han read the forngoing document and known the content thereof; that he has exteuted int same for and on behnif of said company with full power and autho'8 ty i do uo; and that the facts therein stated are true and correct to tue best of his knowledge, information and belief.
By GA+
0 / AMa Carry L.
tandolph Vice President Nuclear SUBSCRIBED and sworn to before me this
//
day of August, 1992.
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J. A. ^t ARV, NOTARY PtJ8UC, STATE OF MISCOUPJ COUf;TY OF MLE My Comtrhsion Ex,dres Oct. 20.1992 1
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T. A. Baxter, Esq.
Shaw, Pittisan, Potts 6 Trowbridge 2300 N. Streee, N.W.
Washington, D.C.
20037 Dr. J, O. Cermak CFA. Inc.
182'.5-A Flower Hill Way Caithersburg HD 20879 $334 i
L. Robert Greger j
Chief,. Reactor Project. Branch 1 U. S. Nticlear Regulatory Comrnission
'Ragion III
?99 Rooseve?.t Road Glen Ellyn, Illinois 61037 Brot.. Bartlett h
Callaway Resident Office
-U. S. Nuclear-Regulatory Commission j
RR#1 S teedtnan, 'lissouri 65077 L. R. Wharton (2) 6 Office of Nuclear Reactor Regulation U
S. Nuclear Regulatory Comraission i-1 White Flint, North, Hail Stop 13E21 11555 Rockville Pike Rockville, MD 20852 Manager, Electr.c Department Hissouri Public Service Commission P. O, Box 360 Jefforson City, MO 65102 non Kucera JDepartraent of Natural Resources P. O. Box 176-Jefferson City, lio 65102 6
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I Attac'tinent 1 Page 1 of 6 ULNRC.2682 MEIL]LVALUATION tronoa d CNvau;:
This citergency annendment request revises Technical Specification 3/4.3.1 Table 4.3 1, Functional Unit 1 (Manual Reactor Trip) and its associated Note 16 which app'.ies to the Trip Actuating Device Operational Test (TADOT). This surveillance requires the following:
"The TRIP ACTUATING DEVICE OPERATIONAL TEST shall independently verify the OPERABILITY of the Undervoltage and Shunt Trip circuits for the Manual Reactor Trip function. The test shall also verify the OPERABILITY of the Bypass Breaker trip circuit."
~
The proposed change adds a footnote which states the following:
U 3
" Complete verification of OPERABILITY of the manual reactor trip switch circuitry shall be performed prior to startup frorn the first shutdown to Mode 3 occurring after August 7, 1992."
backpround:
On August 7, 1992, at approximately 1100 CDT, a routine review of industry operating experience indicated that a licensee with a plant similar to callaway had determined that surveillance procedures for testing mcnual actuation of the reactor trip breakers did not meet Technical Specification requiremen'.s. A review of Callaway procedures and surveillance history indicated a similar deficiency with the testing relied upon to satisfy Tec nical Specification Surveillance.. 3.1.1, Table 4.3 1, Functional Unit 1 (hanual Reactor Trip). Specifically, the current procedures independently test the shunt trip and undervoltage trip functions at the breaker, but do not test the wiring and control room switch contacts for each function.
The testing inade'luacy for the Manual Reactor Trip function TADOT was discussed by Union Electric representatives (Messrs: J. D. Blosser, A. C.
Passwater, et. al.) with NRC Region III and NRC Office of Nuclear Reactor Regulation representatives (Messrs:
W. L. Forney, J. A. Zwo t inski, e t.
al.) on Au5ust 7,1992. During this conference call, Union Electric requested verbal authorization for a Temporary Waiver of Compliance (TWOC) f rom Technical Specification Survoilinnee Requirement 4.3.1.1, Table 4.3-1, Function Unit 1 as it percains to thu M,:nual Reactrr Trip Function TAD 3T.
The NRC authorized the TWOC at 1635 CDT Reference 1 is the written request for the TWOC.
This emergency Technical Specification amendment is required because this surveillance cannot be fully completed with the plant in Mode 1 or 2 without added risk and without special tesi.ing and reconfiguration of the system. Evaluation of this testing is under review to determina its feasibility and its impact on nuclear safety. The plant is currently in Mode 1 at 100% power.
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page 2 of 6 ULNRC+2682 i
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Pe n e t i P.119.D_.gi_t he R e n e t o r Tr i n S y s t e m :
i The Reactor Trip System (RTS) naintains reactor operation within a safe region by automatically tripping the reactor whenever the limita of the region are approached. The RTS automatically initiates a reactor trip:
i a.
Whenever necessary to prevent fuel damage for an anticipated operational transient (ANS Condition II).
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- b. 'To limit core damage for infrequent faults (ANS Condition III),
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So that energy generated in the core is compatible with the l
design provisions to protect the reactor coolant pressure boundary for limiting f'ault conditions ( ANS Condition TV).
1he reactor trip circuits automatically open tFe reactor trip. breakers whenever a condition monitored by the RTS reaches a preset level. To ensuro a reliable system, high quality is_ factored into the design, components, nanufacturing, quality control and testing. In addition to redundant channels and trains, the design approach provides an RTS that monitors numerous ayatem variables, thereby providing protection system functional diversity The extent of this diversity han been evaluated for a wide variety _of_ postulated ac-cidents. Callaway FSAR Section 7.2 describes the RTS detail, including each of the automatic trip functions and the protection provided by each trip.
e A manual trip function is provided es part of the RTS. The msnual trip function consists of.two switches with two outputs on each switch. One output;is-used to actuate the Train A reactor trip breaker (RTB) and the other output actuates the Train B RTB (see FSAR Figure 7.2-1 sheet 2),
Operating a manual trip switch removes the voltage from the undetvoltage trip attachment (UVIA) coil, de energizing the shunt trip relay as well (as is the-case _for automatic reactor trips).-the manual trip. switch also directly energizes the shunt trip attachment (STA) coil The manual reactor trip-function serves as a hackup to the automatic trip functions, only automatic. trip functions are assumed in the analysis of the FSAR Chapter 15 accidcats.
Red and groen position lights are included on the Main Control Board for breaker position, Theso lights are powered from the same fused 125 VDC supply used for closing and shunt-tripping-the circuit breakers, Illumination of the green light indicates that the breaker is open and power is Available for closing and tripping the breaker The red light indicates that_the breaker is-closed.-Since the red 1.ght is connected in serios with-the shunt trap coil, the light-indicates that power is
-available to the shunt trip device and that there'!s circuit continuity in the shunt coil.-This provides an indication that the shunt trip coil is ready to perform its function when required.
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ULNRC 2682 l
E The shunt trip coils.in the reactor trip breakers are powered froe the 12S
.i VDC Class 1E station batteries. Normally, the shunt trip coils are in a de energized condition. When the trip breakers are c1c2od, the red lamp current (approx. 50 nA) flows througb the trip coi1 to monitor the circuit
- continuit,v. This current is not large enour,h to actuate the trip coil armature. The reactor trip signal applies a nominal voltage of 125 V9C to 1
each shunt trip coil in the redundant trains. As the breaker triA9, its auxiliary switch opens to de-energize Lho shunt trip coil.
The Callaway Technical Specifications define the survoillance testing requirements for the RTS, All surveillances associated with the automatic
)
reactor-trip functions are current and the automatic trip function is l
OPERABLE, Technical Specification Table 4.31 Functional Unit 19 (Reactor-Trip Breaker) and its associated Nott 7 requires that each train be tested-on a 6?. day Staggered Test Basis and-the TA00T independently verifles the OPERABILITY of the undervoltage and shunt trip' attachments. This survoillance requirement has _ been met for each RTB and demonstrates the operability of the diverse tripping mechanisms for the RTBn, The current surveillance procedure used for the maruel trip function independently tests the 6 hunt trip and undervoltage _ trip functions at the breakers, but does not test the utring and control room switch contacts for each function, the STA and UVTA, independently.
.The Callaway RTB design included both the undervoltage and shunt trip coils since_the plant was.11consed in 1984. The. pre operational test procedure verified that the undervoltage and shunt trip attachmenen were independently activated from the manual trip switches. NRC Generic Lotter
_05 09 (Refereneo 2) and Reference 3 added this requironent (Note 16 of Yable 4.3 1) to the Callaway Technical Specifications. The undervoltage i
portion of the nanual t' rip function was properly tested in accordance with l
Technical Specifications through Refuel 2 in the-fall of 1987, The shunt trip test specified by Lais procedure has subsequently been determined to be inadequate. Prior to Refuel 3, the requirements for testing the.UV and shunt trip portion of the haudswitch circuitry were deleted for unknown reasons. The manual trip function has beet.itilized to trin the reactor k
du-ing refueling outages at least once everf 18 months _since initial
-startup. This has verified that_the manual reactor trip switches and-
' circuitry provido a reactor trip throuSh at least one path and nost likely both the undervoltage and shunt trip attachments.
- Based on' the. testing history for the manual trip function, t he deslyn of the switch, and:the periodic use of a manual trip switch for plant shutdowns and surveillaneo tests, there is a high degree of confidence that-the~ manual trip circuitry is fully functional. Union Electric is
-investigating the _ circumstances involved in -the revi sions of the j
-aurveillance procedures which led to this tnsting inadequacy.
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s-Page 4 of 6
- UINRC-2682 The Callaway Individual Plant Examination (IPE) evaluates the manual trip for Anticipated Transients Without Scram (ATWS) events. Callaway has an approved AMSAC system installed and operable. A coroplete failure of tha manual trip switches would result in an increase in core damage frequency of 0.5%.
Evaluation:
The proposed chango does not involve an unreviewed safety question because operation of Callaway Plant in accordance with this change would not:
a.
Traolve'an increase in the probability of occurrence or the consequen:es of an accident or malfunction of equipment important to safety previously evaluated in the Final Safety Analysis Report. The reactor trip breaker shunt and under-voltago t. rip actuatiun circuitry is redundant and reliable.
Although.the survelliance testing did not adequately test
- i this portion of the manual reactor trip function, there is no reason to believe that any elenent of the manual-trip function is not functional, if for some reason, nanual-actuation of the shunt trip failed to operate, t.he diversity and redundancy of the reactor protection system would still enab.e it to perform its design function. Emergency Operating Procedure FR 3,1, " Response to Nuclear Power Generation,"
directs the operatorn to perform the following actiorc in the event that the manual reactor trip function is unavailable:
1.
Open the supply breakers to load centers PGl? and PG20, de.enere, iring the CRDM motor generator sets.
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-2 Manual ~ly-insert tiu control rods, p
3.
Ensure the turbine is tripped.
_4.
. Ensure' auxiliary feedwater flow.
' 5.
Initiate-immediate RCS botation.
4 6.
Dispatch an operator to locally open the RTBs.
The accidants evaluated in Chapter la of the Callaway FSAR rely on the autoenatic-trip function of the RTS. No credit is assumed for the manual _ trip function. The automatic portion of the reactor trip system is not impacted by this change. The manan1 pcrtion, because of the highly reliable
- equipment, is essentially unaffected due to lack of testin6-v i
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Thwrefore, since the response of the plant te an accident is unchanged, there is no significant increase in either the probability _or consequences of an accident j
previously evaluated as a result of this proposed change.
b.
LCreate the possibility for an accident or malfunction of equipment of a different type than any previously evaluated in the Final Safety AnalyFis Report. The proposed change does not affect the operation or rerponse of any pl. ant
)
equipment or introduce any new failure ucchanism. Therefore, the previous accident analyses are unchan5ed and bound all expected plant transients and there are no new or differeat accident scenarios introduced.
c.
Involve:a reduction.in the margin of safety as cofined in l
the bamis for any_ Technical Specification. The proposed change vill not reduce the margin oi safety defined in the~ BASES of any Technical. Specification. The BASES of Technical Specification 3/4.3 1. Reactor Trip System Instrunentation. states in part that OPERABILITY of the RTS ensures that a reactor trip will occur when needed.
~~
The accidents evaluated in Chapter 15 of the Callaway FSAR roly-on the automatic trip function _of tne RTS.
No_ credit is assumed for the manual trip function.
3 The RTS possesses several diverse and independent features which enable it to shut down the reactor on demand. The operation of any of these features
. i' demonstrates that the RTS is capable of performing its safety _ tunction. The operation of at least. two of the eight contacts aeccssary to affect a manual reactor trip have been demons.trate i at least every 18 months.
Thereforec the assumptions in the BASES of the Callaway.
' Technical Specifications are not affected and the
- proposed'changs will.not result in a significant reduction in the nargin of safety.
Conqlusinn.
L Based on the preceding discussio.', the proposed change (ior a period of up to 14 months) will not adversely affect or endanger.che health and L
. safety of -the general public. Previous resting and periodic use of the manual reactor trip switches provido a high degree of confidence that the manual' trip circuitry is fully fun;ticnal..The redundancy ard diversity within'the RTS, coupled with the aforementioned surveillances and routine switch use during outages 'and the fact that the manual trip is not assumed ~in~ Chapter 15 accident' analyses provide reasonable assurance that Callaway Plant will continue to operate in a safe manner.
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1.
UtJFC-2681 dated 8/10/92 2.
NRC Ceneric Letter 85 09 dated 5/23/85 3.
U1RRC-1740 dated 1/9/86 d
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Attachtnent 2 Page 1 of 2 UlNRC42682 1.
gJ m fJCANT RAZARDS EVAI,UATJOJ
' This emergency amendment request revises Technical Specification 3/4.3.1, Table 4.3 1, Functionni Unit'l (Manual Reactor Trip) and its associated i
Note 16 which applice to the Trip Actuating Device Operational Test (TADOT). The cucrent surveil. lance procedure independently tests the shunt 6
trip and undervoltage trip functionu at the breakers, but does not test the viring and control roou avitch contects for each function, via the shunt l
trip attachment (STA)_and undervoltage trip attachment (UVTA),
n independently The proposso change is a roodification to !Ote 16 of Table 4.3-1 to defer until the next ' Mode ') shutdown a complete surveillance of this portion of the manual reactor trip circuitry.
The proposed change does not= involve a significant hazards consideration because operation of Callaway Plant. In accordance with this cha.. ige vauld g
not:-
- 1.
Involve a signif'icant increaar.- in the probability or consequences of an accident previously evaluated.
V The manual reactor trip function TADOT was correctly performed dur.ing pre operational testing. Since that time, due to procedural inadequacy, the manual trip surveillances did not verify the operation of control room switch contacts or.tbo wiring from the control boar,1 to the c
reactor trip switchgear. This portion of the circuitry was exercised during. shutdowns;-however, this routine use was not part of a.
surveillance test nor did it confica independent operation of the UVTA and STli. Although.th surveillance testing did not adequately test this port h n of the manual reae. tor trip function,.here;is no reason to
?
believe that any ele:nent of the manual trip function is not. functional.
If:for some reason,' manual actuation of the shunt and UV trip Lfailed to operate, the diversity and dedundancy of the Reactor Protection System would still enable = tt to perform its design function. The accidents
- evaluated in Chapter 15 of the Callaway FSAR rely on the automatic trip function 'of the Reactor Protecticn System. No credit iw assumed for the manual trip function l Purther, all surveillances performed on the
. automatic trip functions, with the independent verification of UVTA collide-energization at.d STA energization via the closing of the shunt L
trip relay contact, havo been performed correctly. Therefore, since the l
response of the plant to an accident is unchanrpt, there is no significant increase in-either the probability. or consequences of an -
acciuent previously evaluated as a result of this proposeu change.
L 2.
Create the possibility of a new or'different kind of accident from any previously evaluated.
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11LNRC 2682' l
i The proposed change does not involve any design changes or hardware
- modifications nor vill there'be any changes to the intended manner cf plant operation or in the method by which any safety-related plant 3
-system performs ita. safety function. No new accident initiators, 1
. transient precursors, failure mechanisms, or limiting single failures are introduced as a result of this change, i
3.
Involve a significant reduction in a marb n of safety.
i The proposed change does not alter the manner'in which safety limits or limiting nefety syste's settings are determined. The proposed change vill ha-o no effect on those plant systems neceasary to assure the i
accomplishment of protection functions and meet. the accident analy sis acceptance' criteria in-FSAR Chapter 15. There will be no impact on DNBR' limits, F F delta il, hoss of Coolant ' Accident Feak Cind Temperature.
ore.nyothe,rdefinedsafetymargin..
- The Bases of-Technical Specification 3/4.3.1 are not chenged since the ability of the Reactor Protection System, with its attendant diversity to ensure the suberiticality function, is not compromiced. While come i
minor _ uncertainty could be postulated to apply to the manual reactor.
trip switch contacts and control room viring to the reactor trip switchgear, lthis in insi nificant when one considers the impact of this l
6 portion of-the circuitry on the overall reactor protection system reliability.-
Based upon the preceding information, it has been. determined that the proposed change.to the Techn cal Specifications does not involve a i
significant increase lin the probability or consequences of an accident pruviouslyfevaluated, cruate the possibility of a new or different kind'of
. accident from any accident previously evaluated, or involve a~significant.
reduction in a margin of safety. - Therefore, it is concluded that the proposed change meets the requirements of 10CFR50.92(c) and doos not.-
Involvo a = significant hazards consideration.
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-UINRC+2d82
,c ENVIRONMENTAL _QCNSIDERATION This caergency amendment request revises Note 16 ~ of Technient Specification Table 4.3 1 by addin6 the following sub. note:
" Complete verif f.eation of OPERABILITY of the snarual reactor trip switch circuitry shall be performed prior to startup from the first shutdown to Mode 3 occurring after August 7, 1992."
-l This is needed due, to a procedural shortcoming in the surveillances for the manual reactor trip switch circuitry.
4 The proposed atsendment involves a change with respect to the suveillance req'41rements of facility components within the restricted area, as defined i
in 10CTR20. Union Electria has determined that the proposed amendment does noc involve:
(1)- A significent hazard conwideration, as discussed in Attachtsent 2 of l
this araendraent application; l-(2) A significant change in the types or significant increase 1.) the 2
amounts of any effluents that may be released offsite; or
' (3) A significar.t increase in Individual or cumolsti e occupational radiation exposure.
Accordingly, the proposed aracndment meets the eligibility criteria for
- categorical exclusion' set forth in 1CCFR51./2(c)(9).- Pursuant to 10CERS1.22(b), no enviroranental_ impact statement or environmental assersment need be prepa*;ed in ecnnection with th issuance of this
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amendment.
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