ML20099F191
| ML20099F191 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 11/16/1984 |
| From: | Andrews R OMAHA PUBLIC POWER DISTRICT |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| LIC-84-370, NUDOCS 8411260301 | |
| Download: ML20099F191 (14) | |
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Omaha Public Power District 1623 Hamey Omaha. Nebraska 68102 402/536 4000 November 16, 1984 LIC-84-370 Mr. Harold R. Denton, Director U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Licensing Washington, DC 20555
Reference:
Docket Na. 50-285
Dear Mr. Denton:
Environmental Qualification of Safety - Related Electrfcal Equipment In a letter dated May 31, 1984, the Omaha Public Power District provided the NRC with documentation based on a March 23, 1984, meeting between District personnel and your staff. This meeting was to provide the staff with current information concerning outstanding items identified by the Franklin Research Center in their Technical Evaluation Report, to enable the staff to issue its final Safety Evaluation Report (SER).
This May 31, 1984, sub ittal contained among other things, a discussion of compliance with 10 CFR 50.49.
The District has subsequently been informed by telephone that additional information would be required in order for the staff to complete its evaluation and issue its final SER.
Several telephone conversations have taken place and the District has agreed to revise portions of the May 31, 1984 submittal to reflect the desired wording.
Accordingly, the attachment to this letter is intended to replace to the District's May 31, 1984, letter in its entirety.
Those changes made are denoted by vertical lines in the right hand margin.
8411260301 841116 PDR ADOCK 05000285 (O
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-The, District-believes this-.information~ accurately reflects our th'e environ--
mental-qualification program"at Fort Calhoun Station.
This should allow-your staff to complete its evaluation of.this matter.
Sine rely,
$ l) { A ///V R. L. Andrews Division Manager 7
Nuclear Prcduction RLA/DJM/dao
-Attachment cc: Leboeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N.W.
Washington, DC 20036 Mr.-E. G. Tourigny Mr..L. A. Yandell I
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s Omaha Publ c Power District Fort Calhoun Stat 4 n Electrical Equipment Qualification Prooram and Compliance With 10 CFR 50.49 (b)(1), (b)k), (b)(3) c s
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History 1
7 The District's present prograt..ibr compliance with the electrical equip-ment in a harsh environnenpqualification ruin 10 CFR 50.49 began in Jan-uary of 1980 wtth the actions required by IE Bulle. tin 79-018 Environmen-tal Qualificqtion of Class 1E Equipment.
The required action expanded the scope of IE,,3ulletin 79-01 and its related ~ documents.
1 The District based its investigation on the DDR Guidelines provided with IE Bulletin 79-01B. The exceptions to this are those items which require different quali fication criteria as provided in NUREG-0578 and subsequent-ly NUREG-0737.-
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Several submittals to the NRC were mad ine' ding the "45 day", "90 day",
" November 1,1980", " Inclusion of Equipment to Achieve Cold Shutdown",
and several to note equipment changes. A large submittal of test reports was also made to the Franklin Research Center, from which the latest TER was written.
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s The District has also responded to one SERtith many specific questions.
The unit is in a refueling outage and the modifications which were dis-cussed in the res'ponse to the TER are to be accomplished. The submittal document used by the District is being transformed ir.to a more stream-lined document to be used duritg the day-to-day' operation by District 4
personnel. Necessary Qualifled Life Program maintenance is to be per-fo med. Documentation open items are to be closed out and the District has hired an independent contractor expOienced in equipment q'ualifica-tion to audit the District's entire Electrical Equipment Qualification Program.
Additionally, the District believes it would be beneficial to explain the manner in which IE Information Notices are handled. Upon receipt, the Licensing Department nakes an assessmentx of the notice to determine the appropriate department for response preparation. An assignment is made and progress is tracked via the District's Licensing Action Log.
The assignment requests a review with respect to applicability, potentiai impact, and possible corrective action. The results of the review are documented for in-house record-keeping purposes and are retained by the District's Licensing Department.
II.
District's Electrical Equipment Qualification " Philosophy" (10 CFR 50.49 (b)(1)
A.
Definition of Equipment Requiring Environmental Qualification:
1.
A master list ~of all equipment required to remain functional during or after a design basis accident (DBA) and which is exposed to a harsh environment as a result of the design basis accident was prepared. The plant specific Loss of Coolant Accident (LOCA) and High Energy Line Break (HELB) 1
11.
' District's Electrical Equipment Qualification " Philosophy" _(10 CFR 50.49.
-(b)(1) (Continued)
.A.
Definition of Equipment Requiring Environ;nental Qualification (Continued) 1.
(Continued) analysis, FSAR Appendix M, identified the LOCA and Main Stean Line Break (HELB) as the only DBA resulting-in a harsh envi-ronnent which required qualification investigation. The actual master list was prepared based on equipment require-ments eind equipment location derived from the FSAR, Technical Specifications, Emergency Procedures, P& ids.(flow diagrams) and electrical diagrams.
The first step in the assessment program was to conduct a re-view of the facility flow diagrams to establish which systems were. required to mitigate the consequences of a LOCA. After the bases for the LOCA conditions were estabitshed, the Dis-trict began an evaluaticr; of the high energy piping systems to detennine where failure of a pipe could cause Engineered e challenged.
Safeguards systems:
u After these lines were identified, a cross-check of areas within.the plant was made to determine if a liELB would affect any Class 1E electrical equipment which was required to func-tion under the postulated accident conditions.
c The components which were identified as a result of the above studies were then further evaluated for their suitability for operation in the postulated environment.
The following is a description of the safety systeins, high energy lines, and areas taken under consideration by the Dis-trict.
c a.
Identification of Safeguards System:
In order to ensure that all of the components required to operate to mitigate design basis events were identi-fied and assessed for their impact on plant safety, a survey of each plant system was made to identify re-
's quired flow paths for accident mitigation.
i In addition, all systems were reviewed for isolation reiuirements after receipt af Engineered Safeguards f
Sign al s.' As a result of this survey, the following e
s systems were identified as either being required to operate or as having conponents which required isola-tion on receipt of Engineered Safeguards Signals:
(1)
(2)
High Pressure Safety Injection System (3)
Low Pressure Safety Injection System 2
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II, District's Electrical Equipment Qualification " Philosophy"-(10 CFR 50.49 (b)(1) ~ (Continued)
-A.
Definition of Equipment Requiring Environmental Qualification (Conti nued) 1.
(Continued) -
a.
Identification of Safeguards System:-(Continued)
(4)
Containment Spray System (5)
Contairnei.t HVAC System'(Containment cooling units and isolation valves)
(6)
Component Cooling System (7)
Raw Water System (8)
Main Steam. System (9)
Steam Generator Feedwater and Blowdown System (10) Chemical and Volume Control System (11) Containment Hydrogen Purg System (12) Control Room Ventilatio: b tem (13)
Instrument Air System (Isol ition valves only)
(14) Plant Air System (Isolation. valves only)
(15) Sampling System (Isolation valves.only)
(16) Demineralized Water System (Isolation valves only)
(17) Waste Disposal System (Isolation valves only)
(18) Electrical Auxiliary Components (which were common for all of the above systems)
(19) Nitrogen System (Isolation valves only)
(20) Charging and Concentrate Boric Acid 6 (21) - Reactor Protective S{ stem 5 (22) ESF Actuation System -
(23) 120 VAC 10 and 130V' DC Instrument and Control Power 2 (24) 480 VAC 30 and 4160-VAC 30 Power 2 (25) Emergency Diesel Generator 2 (26) Ventilation for Areag Containing Safety Related Equipment (27) Post Accident H2 Saapling and Radiction Moni toring (28) Long Term Core Cooling 7 Identification of Safeguards System Notes 1
Engineered Safeguards Actuation - The systen components which initiate safeguards actuation are contained and evaluated as canponents within the systems identified for Fort Calhoun.
2 Emergency Power - The emergency power system for Fort Calhoun consists of two diesel generators and associated distribotion equipment such as switchgear and motor control centers.
In addi-l tion a 130VDC system consisting of fully. redun-dant batteries, chargers and associated distri-bution equipment is available at Fort Calhoun.
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-II.
. District's Electrical Equipment Qualification."Philcsophy" (10 CFR 50.49
'(b)(1) (Continued)
'A.
Definition of Equipment Requiring Environmental Qualification (Continued) 1.
(Continued) a.
Identification of Safeguards System: (s ontinued) 2 (Continued)
None of the postulated accident situations affect the environment where this equipment is located.
Since this is the case, no evaluation of individ-ual components has been done.
Ventilation for. Areas Containing Safety Equipment 3
- Where ventilation equipment is required for op-eration of safety equipment, and it is affected by the postulated event, then it has been as-sessed for the resultant enviromental condi-tions.
4 Emergency Shutdown - The District has perfomed an analysis of the. systems required to bring.the reactor to a cold shutdown condition af ter an-accident involving rapid.depressurization of the primary system with no breach of the reactor coolant pressure boundary.
The safety analysis for Fort Calhoun shows one possible event which could cause this situation to occur. The event is a steam line rupture incident.
Plant emer-gency procedure EP-6 " Uncontrolled Heat Extrac-tion" was referenced to determine those systems necessary to limit the consequences of this event. After review of EP-6, it was determined that there are no additional systems required to function than those which have been previously identified.
5 Reactor Trips - For the LOCA analysis, Low Pres-
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surizer Pressure initiates a reactor trip.
See the following discussion on Small Break LOC A.
Review of the small break LOCA analysis has shown that for all small break LOCAs, low pressure is the parameter which initiates a reactor trip.
The reactor protective system '"PS) uses loop temperatures and reactor power (Delta T or nu-clear whichever is higher) to generate a calcu-lated pressure (thermal margin low pressure) which is fed into a bistable and compared with actual reactor pressure.
If reactor pressure falls below the calculated number, the reactor 4
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II; District's. Electrical Equipment Qualification "Philcsophy" (10 CFR 50.49 (b)(1) - (Continued)
A.
Definition 'of Equipmest Requiring Environmental Qualification (Continued) 1.
(Continued)
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Identification of Safenvards System: (Continued) 5 (Continued) trips.
In addition,_ the bistable is set with an absolute low limit such that no matter what the calculated input, i:he reactor will trip at a pressure no lover than 1750 psig.
It is this-
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1750 psig trip point which trips the plant in the small break LOCA analysis.
Since the failure of unqualified equipment in con-tainment cannot effect the low limit trip valde and the RPS pressurizer _ input are LOCA qualified, no further analysis is required for small break LOCA reactor trip. The remaining equipment used to mitigate a small break LOCA is discussed in the master list.
Discussions with the District's NSSS vendor have indicated that for small steam line breaks, low steam generator levels will be the reactor trip initiating parameter. Therefore, worksheets are included for the low steam generator level LOCA qualified transmitters.
For the MSLB, the reactor trip is initiated by Low Steam Generator Pressure which is LOCA qual-i fied. No other reactor trips are required to be qualified.
Clutch deenergization is accomplished in the con-trol room mild environment.
6 The Fort Calhoun Station Safety Analysis does not take credit for the charging pu.1ps or concentrat-ed boric acid system.
7 The long tenn core cooling system is made up of I
components from other systems previously listed.
See Enclosure 18.
It should be noted that hot shutdown condition is defined as safe shutdown condtion for Fort Calhoun Station.
After identification of the systems had been completed, the system list was cross-checked against Appendix A of the Guidelines for Evaluating Environmental. Qualifica-tions of Class 1E Electrical Equipment in Operating Re-actors.
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II.
District's Electrical Equipment Qualification "Phil'osophy" (10 CFR 50.49 (b)(1) (Continued)
A.
Definition of Equipment Requiring Environmental Qualification' (Continued)
'1.
(Continued) a..
Identification of-Safeguards System: (Continued)
-In general, there is a close correlation between Appen-dix A and the system listed for the Fort Calhoun facil-i ty. However, 'certain specific _ systems are not re-c quired at Fort Calhoun-to achieve a safe shutdown under the postulated accident condition.
In addition, some of the systems listed are unaffected by either LOCA or HELB environments since they'are located outside of affected areas.
It should be.noted that the hot shut-down condition (Mode 4) is defined as safe shutdown condition for Fort Calhoun Station.
A master-list has been prepared for each system, list-ing those components which were identified as Class 1E and which could be affected by a LOCA or a high energy line break. This _ completed the first step of the Dis-trict's review.
All instrumentation identified as being required to function for either automatic operation or required by the operator to make a d: cision on a specific post acci-dent (i.e., long tenn core cooling) has been identified and included in the master list.. Instrumentation which-may aid the operator ir. identification of problem (i.e., contairinent humidity) has not been included since the information provided is of little or no value in a post DBA condition.
Certain of the required NUREG-0737 instruments are in-cluded. See (b)(3) for Supplement 1 (Regulatory Guide 1.97 information).
B.
Establishing Environments 1.
Identification of High Energy Lines The basis for evaluation for HELB affects on Class 1E electri-cal components is Appendix M of the Final -Safety Analysis Report. A review of the high energy lines listed in Appendix M was conducted to detennine which, if any, would have an effect on plant systems and equipment.
It was determined from the review that only a main steam or main feedwater line break could cause an accident condition under which plant safety systems might be challenged. Since a HELB for any other systems listed would not require engineered safeguards 6
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- LII.
iDistrict's Electrical Equipment Qualificatien " Philosophy" (10 CFR 50.49.-
- (b)(1) S(Continued)
.B.
2 Establi shi ng Envi ronments !(Conti nued)
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Identification' of High. Energy Lines (Continued) systems; to operate for any reason, these lines were excluded from this analysis..
q After determination that main' steam and main feedwater lines'
- could cause actuation of: safety systems,.these lines were-reviewed to determine where Class.1E equipment could.be 1 affected as a result. ;Two areas were subsequently _ identified :
and ; investigated in greater depth.
R The first' area:is within the~ reactor containment itself.
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- Since La main steam line break is of more consequence than ~a main.feedwater line break,. the main steam break was addressed. - The Fort Calhounl facility is equipped with an automatic contalment spray system equipped with redundant pumos,-lines and spray headers. As such, i.t is not subject to disabling by single component failures.s Therefore, in
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accordance with Enclosure'4.of IE Bulletin 79-01B,. it has been detennined that the LOCA environnent.will govern.
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qualification of equipment located within the containment.
For a main sten line or main.feedwater line break outside of containment, the only Category 1E electrical equipment which could be affected is located in Room 81. The effects of a main steam or feedwater line break on the environment of Room 81 are discussed in Appendix M of the Final Safety Analysis Report and in Enclosure 2 of this document. The break within -
Room 81, results in the " worst case environment". The anal-ysis conducted on the components within the areas affected was thus governed by the main steam line break, with the exception of flooding.
It is the District's belief that this represents all design basis accidents which result in a harsh environment (includ-l ing flooding) which could expose Jafety related electrical equipment required to function to mitigate the accident to the harsh environment.
9 Flooding within Room 81 is more limited for a main feedwater j
line break and the flood level predicted in the FSAR was utilized to. analyze the components subject to possible flood j
damage. This completed the second step of the District's revi ew.
1.
4 2.
Aress Where Fluids Are Recirculated to Accomplish Long-Term Core Cooling The areas which havelbeen addressed for consideration of fluids from inside containment are Rooms 13, 21, 22, 59, 60, i
and 69. These areas were chosen since this is the only area l
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!. District'A Electrical Equf'pment; Qualification ? Philosophy" (10 CFR 50.49' 3,49 (b)(1)i(Continued) -
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LEstablirMng Environments. (Continued) ~
3.
lloss of CoolantiAccident. (LOCA) -(Continued):
The flood level used-as' the-basis for this ' evaluation is
- 1000.9'. J This level was' arrived at by investigating all pos-L ;e.
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t Esible sources Lof water which could be pumped'into the' contain-to Mnt=or. released from systems within the containment prior to
.' entering the recirculation mode. For conservatism, the en o f.
' tire' contents of the Safety: Injection ~ Tanks, the Safety -Injec -
=d
. tions' Refueling Water Tank, and the Reactor. Coolant. System jo.
were assumed to be dump'ed.into containment prior;.to any recir-llong culation actuation.
The' resultant flood level thus. represents the entire' water -
not' inventory available to mitigate the consequences.of a LOCA'-
qual-and Lis considered to be a conservative : number.
compo-C Component-Qualification Philosophy s
The District's ~" Philosophy" on Electrical Equipmeit Qualification j
stems from the manner (method) in which qualification-was demon-s-
strated. Specifically,.the District's Qualification Program is rm organized to demonstrate-the~1isted equipment's ability to function
'he
- under environmental stress (harsh environment) and have adequate-otor u margin to insure operation, and: operating time.
- ems -
The methods used to demonstrate the comp 1f snce of equipment to the Ds
~ b'ove philosophy can be placed.in four categories:
a As discussed in Section B, "Estabitshing Environments," the FSAR gog.
- was'used to provide LOCA' and HELB infonnation. For. evaluation of onent equipment, plant specific environmental profiles were used as
, doc _
provided in the FSAR Section 14 and Appendix M.
Please note, for-
[ure4 the LOCA profile this was modified by the first SER which required 1oul d the use of 305*F temperature.
icci-Tne methods used to demonstrate the compliance of equipment to the e
above philosophy can be placed in four categories:
.ation trate 1.
For those items where analysis indicated that qualification nennal could not be accomplished or where testing of some type was available, but where analysis to demonstrate complete quali-fication could not be accomplished, a replacement to fully signed
-qualified equipment was, or is presently being, accomplished.
to the of.the
~ The solenoid and limit switch upgrades are examples of equip -
fe r-ment in which analysis indicated that qualification was not j ose i
feasibic. The Foxboro transmitters are examples of.equipraent antai n-h
'which were upgraded when analysis ar.d testing could not be qui red L
combined to demonstrate qualification.
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II.
District's Electrical Equipment Qualification " Philosophy" (10 CFR 50.49 (b)(1) (Continued)
C.
Component Qualification Philosophy (Continued)
As a result of the above-mentioned requiremmits, the District de-fined four levels of required qualification - 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />,1000 hours (42 days),100 days and 1 year. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> specification is applied to equipment whose safety function is completed within a few seconds af ter receipt of an accident signal. This I hour equipcnent was evaluated for the effects of subsequent failure on the safety systems and the potential for misleading the operator.
Where subsequent failure could degrade the plant safety system status or the potential for misleading the operator existed, the level of required qualification was increased. The 1000 hour0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> specification is applied to equipment which is required for LOCA, HELB, or safe shutdown. The equipment in this category functicns during the entire DBE until the plant environments return to essentially the same levels that existed t'efore the postulated accident (see discussion below). The 100 days are expected to be adequate to detect a containment H2 problea and take necessary action. The lone tem (1 year) specification is applied to equip-me lt which must operate for a significant amount of time af ter LOC A and is not accessible during the course of the accident.
Long term is defined as the maximun time necessary to achieve cold shutdow1.
The long tem specification is consistent with Suppirment 2 of IE Bulletin 79-01B.
In some instances the District did not believe a rignrous aging solution was required, as in the case of Fisher 304 limit switches which are not subjected to high temperatures or pressure, and which use materials which do not show significant aging.
The only envi-ronmental stress is that of radiation, for which the witch is tested; the temperature exposure is within the range the vendor feels is correct for the limit switch application.
Since the material shows no significant aging and no radiation induced fail-ures were encountered, the switches are considered quali fied for forty yea rs.
The last area of the EEQ program is that of presentation of infoma-tion to the operator.
This is divided into two areas, accuracy of analog infomation and a othod to insure that instrumentation which may fail does not mislead the operator into taking an im-proper action.
Wi th regard to instrunent accuracy, the District has perfomed anal-yses tc show that although the accident sh ess causes inaccuracies, these should not mislead the operator, or cause actions which are detrimental to plant safety.
Also, for any accident, not all trans-
...i tters are requi red to function, nor could these be expected to give a large amount of useful i n fo rma ti on. This is d_ fined in the a nal ysi s.
l ar those transmi tters which must initiate an automatic action in an accident, the environmental stress induced inaccura-cies are accounted for.
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II.. District's Electrical-Equipment Qualification ~ Philosophy" (10 CFR 50.49
'(b)(1) (Continued).
'C.
- Component Qualification Philosophy (Continued)
The other area of-operator interface is the quick and easy identiff-cation of valid information. The District' believes that this must be presented in a'way which is quickly identified and does not cause confusion. To accomplish this, orange dots have' been' placed on the control board name plates to identify qualified equipment.
This allows 1the operators to conduct post-accident. operation with-out referring to special additional instructions.
III..Qualifled Life Program The District's Qualified Life Program (QLP) is the means by-which the Dis-
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trict has implemented a system which accomplishes several aspects of an ongoing Electrical-' Equipment. Qualification Program... These items may be characterized as,1) qualified equipment tracing program, 2) qualifica-tion documents, 3) maintenance or refurbishment schedule.to maintain qual-ification,. 4) breakdown maintenance, and 5) future modification control.
As implemented,. administrative and ' technical direction for the QLP re-sides in three documents,1) Fort Calhoun Station Standing Orders, 24 Gen-erating Station Engineering fiar.ual, and 3) the Electrical Equipment Quali-fication fianual. -
The QLP's operation is summarized in the-following discussion.
First is the actual maintenance of. qualification (refurbishment to ac-count for aging). This is accnnplished by the' previously discussed ' Items 1, 2 and 3.
The District has elected to maintain a central file which contains, in the District's judgment, all the test and analysis documents necessary to establish equipment qualification. These documents (tests,.. analyses, etc.)~ must be tied to field equipment to both demonstrate qualification and establish any needed refurbishment interval. This is done in the fonn of an Equipment Qualification Documentation Fonn (EQDF) in which one of these, per device, is issued.
Once necessary maintenance (or cycling) has been-identified, the refur-bishment, including procedures, must be placed in the plant maintenance system. Thc ef fort is controlled by plant Standir.g Order.
fiaintenance Procedures were written as required to refurbish.
- However, maximum 'use was made of existing' plant procedures including surveillance tests, calibration procedures, and existing preventive maintenance proce-dures.
When refurbishment is completed, an FC-198 fann is completed which up-dates the central file to document continued qualification.
It should be noted that although such things as cycling are noted and accanplished, the central file is not updated.
In many of these cases existing proco-dures are used.
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11112 Qualified-Lifa Program (Continutd)L
' Breakdown maintenance'and equipment -failure is controlled under plant
- S.tanding Orders..These controls insure compliance with 10 CFR 50.49 -
spare.or replacement parts. _ and documentation of. continued ~ qualifica-
. tion.'
If the repair ' requires replacement and 'an upgrade to NUREG-0588 is to-be-
'done, the. station modification controls (to be discussed later) are used.
If a subcamponent-is replaced ~or'a one-for-one replacement is justifled
- (sound reasons to the cnntrary) the FC-198 is~used to establish continued _
quali fic'ation.
In order ~to insure future: qualification of yet to be installed (and un-known) modifications it is necessary that all modifications:to thesta-
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tion be included in.the QLP if their function warrants-inclusion. To accomplish this,' Standing Orders have been updated to insure that equip-o ment.is included in the ongoing program. Other administrative control
' documents related to station modification control-(GSE Manual 'and the EEQ Manual) serve to insure-all modifications' meeting the QLP criteria are -
treated in the same manner as the equipment originally in the QLP scope.
Update of all _ document files ~, procedures,:and programs will be' handled in the same manner as other. document and program updates, as required by plant standing orders governing modifications.
It shoulc be noted that the QLP documents -provide guidance as to how to establish qualfr'ication, fill out necessary fonns, and evaluate vendor i n formation.
To summarize, the District's QLP accomplishes.three major test tasks,1) 4 -
documents qualification, 2) actually maintains equipment in a qualified condition, and 3) accounts for future unknown modifications. The Dis-i trict believes this is accomplished within the guidance of 10 CFR 50.49.
IV.-
District Position on 10 CFR 50.49(b)(2) 10 CFR 50.49(b)(2), "Nonsafety-related electrical equipment whose failure under postulated environmental conditions could prevent satisfactory accomplishment of safety functions specified in subparagraphs (i) through (iii) of this section by the safety-related equipment."
It is the District's engineering judgement that the Fort Calhoun Station is in compliance with the requirement of 10 CFR 50.49(b)(2).
I A review conducted to ensure that all equipcent contained in the master list will perfom its required function, and that no other equipment failure can compromise this action.
As stated in item II, the equipment master list was generated to include all equipment which must remain functional during or after a design basis accident and which is exposed to a harsh enviroment as a result of the l
design basis accident. The plant specific Loss of Coolant Accident (LOCA) and High Energy 1.ine Break (HELB) analysis, FSAR Appendix M, i
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h III; Qualified Lifa Program (C:ntinutd)
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. identified the L'0CA 'and Main. Steam Line' Break (MSLB)' as the only DBA H
resulting in a harsh environment which requires equipment qualification.
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_ The actual master list was prepared based on'DBA equipment requirements, and equipment location based on the FSAR, Technical. Specification,~ Emer-gency Procedures, P& ids ~(flow diagrams and electrical diagrams). This.
4-list includes' auxiliary devices in the electrical circuit also exposed to-t the harsh environment, which sould prevent the operation of the safety-related (required to function) component. ' Also included are the auxil-iary system (ventilation, cooling water, etc.) which are required for the operation of the. safety-related system or components.
A review of the effects of the failure of non-safety related equipment was made. With regards to electrical isolation and. faults, the Fort Cal-houn Station instrument and control power and three phase AC (4160V.and 480V) systems are designed with isolation devices such as fuses to clear any faults which may occur. A fault on-a non-safety related device
~ hould, therefore, not affect the operation of a safety-related device.
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The District = also ~ believes that physical proximity should not be 'of con-cern. The electrical protection should isolate any equipment before cat-astrophic -(i.e., explosive) failure occurs. This is supported by the separation and segregation design criteria. The results of reviews of IE Bulletin 79-22 on potential unreviewed safety questions caused by the in-teraction'of nonsafety-related and safety grade systems, and IE'Bulletin 79-27 on the adequacy of station instrument ar.d control power distribu-tion systems insure the integrity of the safety related components, it should be noted that station modifications were similarly evaluated.
L Any equipment identified was included for qualification in the master list.
s V.
Certain Post Accident Monitoring Equipment (b)(3)
It is the District's judgement that post accident monitoring equipment has been adequately considered. Those items required in the Station Emergency Procedures have been identified and qualified for the required function and environment. This includes those items' required by NUREG-0737.
4 Any changes or upgrades to accident monitoring equipment will be imple-mented on the negotiated schedule.
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Final in.plementation of post accident monitoring equipment and its scope was directed by NUREG-0737, Supplement 1, which required the review and implementation of Regulatory Guide 1.97 (Rev. 2).
This is an' ongoing
- program with a schedule ne.gotiated by the Fort Calhoun Station Project Manager.
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