ML20114A847
| ML20114A847 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 08/17/1992 |
| From: | Bailey J WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20114A849 | List: |
| References | |
| NO-92-0247, NO-92-247, NUDOCS 9208240010 | |
| Download: ML20114A847 (14) | |
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WQLF CREEK NUCLEAR OPERATING CORPORATION t
" John A. Bailey wee Prwdent -
August 17, 1992
- operations NO 92-0247
~
U. S._-Nuclear Regulatory Commission ATTN Document Control Desk Mail" Station P1-137 Washington, D. C. 20555
Reference:
Letter NO-92-0246 dated August 17,
- 1992, from J. A. Bailey, WCNOC to the U.
S.
Nuclear Regulatory Commission
Subject:
Docket No.
50-482:
Emergency Technical Specification Change to Surveillance Requirement 4.3.1.1
~ Gentlemen:--
The purpose of-this letter is to transmit an appli etion for emergency amendment'to Facility. Operating License No. NPF-42_fordiall Cro n Generating Station (WCGS),
Unit'No.
1.
-This. emergency license amendment request
_ proposed a-one' time. extension to.the surveillance interval specified for Technical' Specification Surveillance 4.3.1.1 Table 4.3.,-Functional Unit 1 (Manual Trip).
As indicated in Attachment IV, the surveillance of the control room manual reactor trip-switch shunt -trip contacts would be deferred.until-the next entry into Mode 3. Hot Stc.ndby.
The refertnce; transmitted.a request for Nuclear Rea'ctor
- e,ulation (NRR)_
r
-Temporary Waiver-of-Compliance from the-requirement of Technical
? Specification Surveillance Requirement 4.3.1.1 for which verb. approval was granted on' August 14, 1992.
~0n Aigust 14,_1992 atlapproximately 1130 CDT, a review of industry operation L
experience and discussions.with a plant'similar:to WCGS had determined a N
need to request a Temporary Walver of Compli'.ce for_the above surve311ance h
requirement.
Current procedurt: ' independently test the shunt
- rip and l
undervoltage trip-functions at the'bteakers but do not test the control room manual l reactor trip shunt trip contact closure. A review of WCGS procedures l3 and: plan-records determined that it was likely'that no other surveillance-f
' procedure had. accomplished the' intended testing.
l."'
Attachment I providesia dascription of the amendment along with a Safety Evaluation ~
At tachment II provides the:Signif cant Hazards Consideration l Determination.
Attachment III provides the Environmental Impact
- 1. Determination.
The _ proposed changes to the technical specification-is provided: in Attachment IV.
v208240010 920817
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NO 92-0247 f
' Page:2 4f 2 Y
-Pursuantito.10.CFR 30.91(a)(5), WCGS hereby requests emergency authorization tand-approval' of -this proposed. amendment.
The requested emergency authorization. 'is' appropriate because. this amendment request involves no significant hazards consideration (Attachment II)..This emergency Technical Specification - ' amendment is required because.this surveillance cannot be fully; completed with the plant in Mode 1 Power Operation, or Mode-2 Startup.
- The results of the safety evaluation (Attachment I) show thtt the reactor. trip system remains functional and that the effect cf deferring the surveillance is minimal.
There is -nr adverse effect on~the health and safety of the public.
The WCGS Plant Safety Review Committee-and the Nuclear Safety "eview Committee have. reviewed and approved this-request.
Inaccordance with 10 CFR-50.91, a copy of this application, with atte. hmento is being-provided to the designated Kansas State Official.
If you have any questions concerning this matter, please contact me or Mr. Kevin J. Moles of'my staff.
Very truly yours,
(,lz OA
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John A. Bailey Vice President Operations JAB /jra Attachments I.
. Safety Evaluation II - Significant Hazards Consideration Determination III - Environmental Impact Determination
+-
IV. Proposed Technical Specification Change cci-G. W -Allen (KDHE), w/a
-A.
- t. Howell (NRC),.w/a J.-L. M11hoan (NRC) w/a G. A. PickL(NRC), w/a-W. D. Reckley (NRC), w/a i
STATE OF KANSAS
)
) SS COUNTY OF COFFEY
)
John A. Bailey, of lawful age, being first duly sworn upon oath says that he is Vice President Operations of Wolf Creek Nuclear Operating Corporation; that he has read the foregoing document and knows the content thereof; that he has executed that same for and on behalf of said Corp ation with full power and authority to do so; and that the facts therein s'sted are true and correct to the best of his knowledge, information and belief.
By 3
^
~1 John A. Bailey Vice President Operations
/ 7 day of bujuSI, 1992.
SUBSCRIBED and sworn to before me this
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Attachmsnt I to NO 92-0247
~ Page 1-of 6 4
ATTACIMENT I s
SAFETY EVALUATION
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Attachment I to NO 92-0247 Page 2 of 6 Safety Evaluation Proposed Change The purpose of the proposed emergency Technical Specification change is to revise Technical Specification 3/4.3.1 Table 4.3-1, Functional Unit 1 (Manual Reactor Trip) and its associated Note 11 which applies to the Trip Actuating Device Operationa'. Test (TADOT).
This surveillance requires that the TADOT independently verify the operability of the undervoltage and shunt trip circuits for the manual reactor trip function and verify the operability of the bypass breaker trip circuit.
The proposed change would add a footnote which states that complete verification of operability of-the manual reactor trip switch circuitry be performed prior to startup from the first shutdown to Mode 3. Hot Standby, occurring after August 14, 1992.
Background
On August 14,
- 1992, at approximately 1130
- CDT, a review of industry operating experience and discussions with a plant similar to Wolf Creek Generating Station (WCGS) had determined that surveillance procedures for testing manual actuation of the reactor ttip breakers did not meet Technical Specification requirements.
A review cf VCGS procedures and surveillance history indicated a similar deficiency wtth the testing relied upon to satisfy Technical Specific 8 tion Surveillance 4.3.1.1, Table 4.3-1, Functional Unit 1 (Manual Reactor Trip).
Specifically, the current procedures in-tependently test the shunt trip and -undervoltage trip functions at the breakers but do not test the control room manual 3
reactor trip switch shunt trip contact closure.
l The testing inadequacy for the manual reactor trip function TADOT was discussed by Wolf Creek Nuclear Operating Corporation (WCNOC) representatives with NRC Region IV and NRC Office of Nuclear Reactor l
Regulation represantatives-on August 14, 1992.
During this conference call.,
VCNOC requested verbal authorization tor a Temporary Waiver of Compliance (TWOC) for Technical Specification Surveillence Requirement 4.3.1.1, Table 4.3 1, Functional Unit 1 as it pertains to the manual reactor trip function TADOT.
The NRC authorized the TWOC at 1415 CDT.
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j This emergency Technical Specification amendment is required because this l
surveillance cannot be fully completed -with the plant in Mode 1, Power Operation, or Mode 2, Startup.
The plant is-currently in Mode 1 at -100%
power.
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- A'ttachment I to NO. 92-0247
- Page 3 of.6 4
Description;of'the Reactor Trip System The-Reactor Trip System _ (RTS) maintains reactor operation within a safe region by automatically tripping the reactor whenever the limits of the region are approached.
The_RTS automatically initiates a reactor trips a.
Whenever necessary to prevent' fuel damage for an anticipated operational transient (American Nuclear Society (ANS) Condition II).
b.
To limit core damage for infrequent faults (ANS Condition III), and c..
So-that energy generated in the core is compatible with the design provisions to protect the reau.or coolant ' pressure boundary for limiting fault conditions (ANS Condition IV).
The reactor.-trip circuits-automatically open the reactor trip breakers whenever a condition monitored by the RTS reaches a preset level. To ensure a reliable system, high quality is factored into the design, components, mnwnacturing, quality-control and. testing.
In addition to redundant
- channels and-trains, the design approach-provides an RTS that monitors numerous systems variables, _thereby providing protection system functional diversity.
The. extent of this diversity has teen evaluated for a' wide variety of iSstulated accidents.
Volf. Oteek Generating Station (WCGS)
Updated Safety Analysis Report (USAR) Section
.7.2 describes the RTS in
- detail, including each of the automatic trip functions and the protection
_provided by each trip.
A manual trip. function-is provided as part of the RTS.
The manual trip function consists of Jtwo switches with two outputs on each switch.
One output is fused to actuate the Train "A" reactor trip breaker (RTB) and the other output actuates the Train "B" RTB (see U!Uut Figure 7.2-1 sheet 2).
Operating _ a manual; trip. switch removes the voltage from the undervoltage trip attachment.(UVTA) coll, _ 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.
- he manual reactor trip, function. serves as a backup to the automatic trip functions.
Only automatic trip functions are assumed in the analysis of accidents described l
- in Chapter 15 of the VCGS USAR.
Red-and_ green position lights are included on the Main Concrol Board for breaker' position.
These lights are powered from the samt_ fused 125 Volt DC supply used for closing and shunt-tripping the circuit breakers.
Illumination of the green. light indicates that the breaker is open and power L
is available for closing and tripping the breaker.
The red light indicates that the breaker-is closed.
Since the red light is connected in series with the i shunt trip coil, the light indicates that power is available to the shunt trip device and that there is 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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Attachment I to N0'92-0247
-Page 4 of 6 c
4 The; shunt-trip coils in the reactor trip breakers are powered from the 125 Volt DC Class 1E station batteries.
Normally, the shunt trip coils are in a de-energized condition.
When the trip breakert are closed, the red lamp current- (approximately 50 -m1111 amperes) flows through the trip coil to monitor the circuit continuity.
This' current is not large enough to actuate the trip coil armature.
The reactor trip signal applies a nominal voltage of 125 Volt DC to each shunt trip coil in the redundant trains.
As the breaker trips, its auxiliary switch opens to de-energize the shunt trip coil.
The WCGS Technical Specifications define the surveillance testing requirements for the RTS.
All qurveillances associated with the automatic reactor trip functions are current and the automatic trip function is operable..
Technical Specification Table 4.3-1' Functional Unit 19 (Reactor Trip Breaker) and its associated Note 7 requires that each train be tested on a 62 day Staggered Test Basis and the TADOT independently verifies the
, operability of the -undervoltage -and shunt trip attachments.
-This surveillance requirement has been met for each RTB and demonstrates the operability of-the diverse tripping mechanisms for the RTBs, The current. surveillance -procedure used for the manual _ trip function
-independently tests the undervoltage trip functions to the breakers, but does not test the control room switch contacts for the shunt trip function.
The WCGS RTB design included both the undervoltage and shunt trip coils since-the plant was licensed in 1985.
The pre-operational test procedure verified that the undervoltage and shunt trip attachments were independently activated from the manual trip switches.
" Technical. Specification For Generic Letter 83-28,' added this requirement (Note 11 of Table 4.3-1) to the WCGS Technical Specifications.
Based on the testing. history for the manual trip function, the design of the switch, and the periodic useiof a manual trip switch for_ plant shutdowns'and
. surveillance tests, there is a high degree of confidence that the manual trip circuitry is fully functional.
Evaluation:
The proposed change does not involve an unreviewed safe;y question because i_
operation of VCGS-in accordance with this change would not a.
. Involve an increase in the probability of occurrence or the consequences of an accident or malfunctinn of equipment important to-safety previously evaluated in ti e US AR.
The reactor trip breaker shunt and undervoltage trip ' actuation circuitry is redundant-and reliable based on the testing history for the manual trip function, the design of the switch, and the periodic use of a manual trip sw?tch for plant shutdowns and surveillance tests.
Although the surveillance testing did not adequately test the shunt trip _ portions of the manual reactor trip function, there _is no reason to-believe that any element of the manual trip actuation of g
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fAttachment I to NO-92-0247
-Page151of;6' the phunt trip would fail to_ operate.
The diversity and redundancy of the reactor _ protection system would still enable it to perform its design function.
Emergency Operating Procedure FR-S1,
' Response to Nuclear Power Generation /ATWT,' directs the-operators to perform the following actions in the event that the manual
-reactor trip function is unavailable:
.1.
Open the supply breakers to 480 Volt AC load centers PG19 and de-energizing the Control Rod Drive Mechanism motor trator sets.
2.
Manually-insert the control rods.
3.
Ensure the turbine is tripped.
4.
Ensure auxiliary feedwater flow.
5.
Initiate ~immediate. Reactor Coolant System boration.
6.
Dispatch an operator to locally open the RTBs.
The-accidents evaluated in Chapter 15 of-the WCGS USAR rely on the
-automatic 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 char,ge.
The manual portion, because of the highly. reliable equipment, is essentially unaffected due to lack of testing.
.Therefore, since the response of the plant to an accident is unchanged,--
there-is no significant-increase-lu either the
-probability or consequences of an accident.previously evaluated as aLresult of this proposed change.
b.
_ Create the possibility for an accident or malfunction of equipment
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_of a different type than any previously-evaluated in the USAR.
The proposed _ change. does. not affect the operation or response of any plant equipment or introduce any new failure mechanism.
Therefore, the; previous accident analyses are uncbanged and bound all expected
_ plant _ transients and there are no new or.different. accident scenariosLintroduced.
_. c.. Involve a reduction in the margin of safety as defined in the basis for any~ Technical Specification.
.The proposed ~. change will not
-reduce the margin of safety defined in the BASES of any Technical
. Specification. ~ The bases aof Technical Specification 3/4.3-1, Reactor
. Trip-System Instrumentation, 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 WCGS USAR
~
rely on the. automatic trip function of the RTS.
No credit is assumed. for the_ manual trip function.
The RTS possesses several g_
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Attachment ILto'NO 92-0247 Page 6:of 6 diverse ~and independent features which enable it to shut down' the.
reactor on -demand.
The operation of any of_ these features
.demonstratss-that the RTS is capable of performing its safety
_ function.
The operation of the undervoltage contacts necessary to affect a manual reactor trip have been demonstrated at least every 18 months.
Therefore, the assemptions in the bases of the WCGS Technical Specifications are not affected and the proposed change will not result in a significant reduction in the margin of safety.
Conclusion Based on the preceding-discussion, the proposed change;(for a period of up to?8 months) will not adversely affect or endanger the health and safety of
-the general public.
Previous testing and periodic use of the manual reactor trip switches during outages. provide a high degree of confidence that the manual trip circuitry. is fully functional.
The redundancy and 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 WCGS will continue to operate in a safe mauner, u
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' Attachment II to NO 92-0247' Page 1.of 3 ATTACIAIENT Il SIGNIFICANT IIAZARDS CONSIDERATION DETERMINATION A
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Attachment Il to NO 02-0247 Page 2 of 3
. Signification Hazards Consideration Determination This emergency amendment request revises Technical Specification 3/i.3.1, Table 4.3-1, Functional Unit 1 (Manual Reactor Trip) and its associat ed Note 11 which applies to the Trip Actuating Device Operational Test (TADOT).
The current surveillance procedure independently tests the undervoltage trip functions of the manual trip switches to the breaker, but does not test the
. shunt contacts.
The proposed change is modification to Note 11 of Table 4.3-1 to defer shutdown a complete surveillance of this portion of he manual reactor trip circuitry until the next entry ato Mode 3, Hot Standby.
The proposed change does not invnive a significant hazards consideration because operation of WCGS in accordance with this change would not:
Standard 1 - Involve a
Significant Increase in the Probability or Consequencet of an Accident Previously Evaluated The manual reactor trip function TADOT was correctly performed during pre-operational testing.
Since that time, due to procedural inadequacy, the manual trip surveillance did not verify the operation of control room switch shunt trip contacts to the reactor trip switchgear.
This portion of the circuitry was exo!cised at-least once every 18 months during shutdowns;
- however, this routine use was not part of a surveillance test nor did it confirm -indept;ndent operation of the shunt contacts.
Although the surveillance testing did not adequately test this portion of the manual reactor trip function, there is no reason to believe that'any elemect of the manual trip _ function is not functional.
If for some reason, manual actuatian of the shunt trip failed to operate, the diversity and redundancy of the Reactor Protection System would still enable it to perform its design function.
The accidents evaluated in_ Chapter 15 of the WCGS USAR rely on the automatic trip function of.the reactor protection system.
No credit is assumed for the manual trip function.
- Further, all surveillances performed on' the automatic trip functions, with the jndependent verification of UVTA g
coil dem nergizatian and STA energization_via the closing of the shunt trip relay contact, have beea performed correctly.
Therefore, since-the response of_the plant to an accident is unchanged,_ there is no significant increase i
in either the probability or consequences of an accident previously evaluated as a result of this proposed change.
Standard 2 - acate the Possibility of a New or Different Kind of Accident from any Previoucly Evaluated The proposed change does_not involve any changes or hardware modification nor will there be any changes to the intended manner of plant operation or in the method by which any cafety-related plant system performs it safety function.
No new accident initiators, transient orecursors, failure mechanisms, or limiting single failures are introduced as a result of this change.
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Attachment II to NO 92 0247
.Page 3 of 3
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l Standard 3 - Involve a Significant Reduction in the Margin of Safety The proposed change does not alter the manner in which safety limits or limiting safety system settings are determined.
The proposed change. vill have no effect on those plant systems necessary to assure the accomplishment of protection functions and meat the accidant analysis acceptance crite-la in Chapter 15 of the WCGS USAR.
There will be no impact on Departure from. Nucleate Rolling Ratio limits, F,
F-delta-H, Loss of Coolant Accident-Peck Clad *e.mperature, oraby~
other defined safety margin.
The rases of Technical Specification 3/4.3.1 are not change since the ability of the Reactor Protection System, with its attendant diversity to ensure Le subcriticality function, is not compromised. While some m.'.nor uncertainty could be postulated to apply to the manual reactor trip switch shunt trip contact to the reactor trip switchgear, this is insignificant when one considers tne impact of this 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 Technical Specification does not involve a
significant increase in the probability or consequences. of an accident previously evaluated,. create the possibility of a new of 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 requi 9ments of 10 CFR 50.92Tc) and does not involve a significant hazards consideration.
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Attachment III to NO 92-0247
' Page 1 of 2 O
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ATTACIMENT III ENVIRONMENTAL IMPACT DETERMINATION i
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~AttachmentLIII t'o NO 92-0247 EPage_2fof-2
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.This emergency amendrent request revises Note 11'of Technical Specification'
~
Table 4.3-1-by adding the following.sub-note:
" Complete verification of OPERABILITY of the manual--reactor trip
-switch. circuitry shall.be performed prior to startup from the first shutdown to Mode 3-occurring after August 14, 1992.'
'This is needed Joe.to a procedural shortcoming in the surveillances for the manual' reactor trip switch circuitry.
The ' proposed amendmen; involves a shange with respect to the surveillance requirements of facility components t'ithin the restricted-area, as defined Lin 10 CFR 20.
Volf Creek Nuclear Operat'ing Corporation has determined that the proposed' amendment does not involves
- (1)_ A significant hazard consideration, as discussed in Attachment II of
.this~ amendment applications (2) -A.
significant. change in the types or significant increase in the.
amounts of-any effluents that may be release offsite; or
[
(3) !A 'significant increase in individual' ar cumulative occupational radiation exposure.
Accordingly,
.the' proposed. amendment meets -the eligibility criteria for
-categorical exclusion Eset forth-.in 10.CFR-51.22(c)(9).
Pursuant to-
~10 FR 51.22(b),.
no environmental impact statement or environmentel
-assessment need-te - prepared--in connection with the issuance of this 1
amendment, e
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