ML20003G119
| ML20003G119 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 04/15/1981 |
| From: | Carey J DUQUESNE LIGHT CO. |
| To: | Varga S Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.2, TASK-TM TAC-45114, NUDOCS 8104280310 | |
| Download: ML20003G119 (11) | |
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, kN United States Nuclear Regulatory Commission
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Director of Nuclear Reactor Regulation
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Mr. Steven A. Varga, Chief
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[b Operating Reacters Branch No. 1
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Washington, DC 20555 g
Reference:
Beaver Vallev Power Station, Unit No. 1 M/
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\\O Docket No. 50-334, License No. DPR-66 Response to E* REG-0737, ICC Instru=ent System Gentlemen:
Forwarded herewith is the Evaluation Report of the ICC instrument System (Inadequate Core Cooling) conformance to NUREG 0737 Item II.F.2 criteria in accordance with our letter dated December 31, 1980.
This evaluation revealed that the requirements for the ICC system can be met by the Westinghouse Reactor Vessel Level Instrument System (RVLIS) with the Core Exit Thermocouples (CETC's). The evaluation of the CETC's will be submitted by July 1, 1981 as indicated in our letter of December 31, 1980.
If you have any questions regarding this response, please contact my office.
Very trulv yours, J. J. Carey Vice President, Nuclear cc:
D. A. Beckman, Resident Inspector U.S. Nuclear Regulatory Commission Beaver Valley Power Station f'o%
Shippingport, PA 15077 U.S. Nuclear Regulatory Commission 3
c/o Document Management Branch Washington, DC 20555
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EVALUATION OF THE INADEQUATE CORE COOLING (ICC)
INSTRUMENT SYSTE3 FOR CONFORMANCE TO NUREG 0737 ITEM II.F.2 INCLUDING
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ATTACHMENT 1 AND APPENDIX B l
This discussion presents the evaluation of the' instrument system planned for detection of inadequate core cooling (ICC) for its conformance i
to the criteria contained in NUREG 0737 Item II.F.2 and Appendix B.
Eval-uation and proposed actions pertaining to the core-exit _thermocouples to the criteria of Attachment 1 will be provided by July 1,1981 as _ identified in the Duquesne Light Company response of December 30, 1980 (Reference 1) to NUREG 0737.
===.
Background===
During Duquesne Light Company's preparation of the response to'NUREG 0737 Item II.F.2 due on January 1,'
1981,'the evaluation of the ICC Instrument 4
System was deferred pending evaluation of additional information specific to Beaver Valley Power Station, Unit 1 since the bulk of material available and under evaluation was generic rather than plant specific..
Discussion l
This evaluation of the ICC Instrument System includes identification-i of the components constituting the ICC Instrument System, the basis for this selection of component instruments and a completed checklist on these components itemizing the criteria contained in both Item II.F.2 and Appen-dix B to NUREG 0737 and indicating whether the critetta is met, including any proposed action if the criteria is not met.. The av hod of evaluation using the checklist is to indicate briefly how conforman o is considered achieved and identify the source document and specific section supporting that conclusion.
It should be noted that since the plant specific ICC l
Instrument system desip is not completed for Beaver Valley Power Station, i
Unit 1, some of the criteria is not stated as met but it is intended that the criteria will be met by the final system design.
System Components for the Inadequate Core Cooling Determination System The substantial amount of analysis of events which may lead to conditions of inadequate core cooling performed in response to item I.C.1 of NUREG 0737 and the procedures which have evolved from that analytical effort have identified a number of instruments which are important in determining the adequacy of core cooling. These instruments include: a) reactor coolant system pressure and temperature, by use of which the degree l
of subcooling can be determined by use of steam tables, b) the subcooling monitor, c) the reactor vessel water level instrument system and, d) the core exit thermocouples..Each of these instruments or instrument systems provides information to the operator by which he may assess the adequacy.
of core cooling. Item II.F.2 of NUREG 0737 recuires information related to instrumentation used in addition to the subcooling monitor for deter-mining the adequacy of core cooling, l
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Duquesne Light Company letter entitled " Response to NUREG 0737," dated December 31, 1980 provided a response to all items of documentation required under II.F.2 except the conformance of the additional ICC instruments to the criteria set forth under Item II.F.2 This report documents the degree to which the reactor vessel level instrument system (RVLIS) conforms to these criteria:
We conclude that the RVLIS meets the intent of the criteria set forth in item II.F.2 with the following clarifications:
1) the criteria for. unambiguous indication requires that core exit thermocouple indications be used.
Full evaluation of the suita-bility of core exit thermocouples will not be complete until July 1, 1981, as stated in our December 31, 1980 response to NUREG 0737, 2)
Classification Item No. 5 of Appendix B evaluation check list is not specifically complied with but an alternative which we believe is acceptable is set forth in the attachment.
3)
Classification Item No.18 speriodic testing) invokes IEEE-338-1977 whereas our iqplementation of RVLIS will incorporate IEEE-338-1971.
REFERENCES Duquesne Light Company letter to the NRC, dated December 30, 1980 1.
.with attachment titled: " Response to NUREG 0737" 2.
Westinghouse Electric Corporation summary report: Westinghouse Reactor Vessel Level Instrumentation System for Monitoring Inadequate Core Cooling (Microprocessor System), dated December, 1980-(Submitted with Reference 1) 3.
Westinghouse letter to DLC, DLWPO-18: " Reactor Vessel Level Indication," dated October 10, 1980 4.
Westinghouse letter to DLC, Mr. R. C. Schopper: " Reactor Vessel Level System" dated July 9, 1980 o
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ITEM II.F.2 NUREG 0737 Iudequate Core Cooling Instrument System Evaluation Checklist : Design and Qualification Criteria for Pressurized Water Reactor Incore Thermocouple Conformance: Yes or No (Specify Classification Ref. No., Page No., Para. No.,
Item No.
or Explanation & Justification (Page No.)
Requirement for Planned Actions)
Gen'l Reg't Easy-to-interpret indication Yes.
(Ref. 2, para. 1.1) "RVLIS (3-113) provides a relatively simple and straightforward means to monitor vessel level."
l Unambiguous Indication No.
Ref. 2, para. 4.5.3 indicates need to use in conjunction with core exit thermocouples.
4 Unambiguous Indication (a) ICC caused by (1) Hi-void fraction Yes.
(Ref. 2, para. 1 & 4.4) "...
to indicate... relative void content of the circulating primary coolant.."
(2) Stagnant Boil-off No.
(Ref. 3, Item 6 and Ref. 2, para. 1.1 and 4.4).
Vessel level i
measured is the collapsed liquid level. Core Exit T/C's required.
(b) Must not erroneously indicate ICC No.
(Ref. 3, Item 7) Westinghouse due to unrelated phenomena indicates that it is possible that i
an erroneous indication of ICC could occur; however, the time period i
l would be brief (approx. 1 min.)
5 Give advanced warning of approach of Yes.
(Ref. 2, para. 2.2 & 4.5) l ICC
"... accuracy requirements... assure that the vessel level reading can be reasonably used to aid in the detection of the onset of ICC conditions."
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Cover full range from Normal Operation Yes.
(Ref. 2, para 2.2 & 4.5) to Complete Uncovery
"... instrument will cover the full range of expected differential l
pressures..."
i t.
ITEM II.F.2 NUREG 0737 Inadequate Core Cooling Instrument System Evaluation Checklist : Design and Qualification Criteria for Pressurized Water Reactor Incore Thermocouple Conformance: Yes or No (Specify Classification Ref. No., Page No., Para. No.,
Item No.
or Explanation & Justification (Page No.)
Requirement for Planned Actions)
-7 Evaluate all instrumentation in final See Appendix B evaluation.
ICC per Appendix B.
8 If computer used, it must be access-To be met.
Plant specific design ible for maint. following accident, and installation will assure access-ibility of the microprocessor and remote CRT display.
(a) Beyond isolation device need not To be met.
be Class lE (b) Energized with Hi-reliability Yes.
(Ref. 2, Table 4.1) Class lE power source power source indicated.
(c) Battery backed power source To be met.
(d) QA of App. B, Item 5 is not Noted.
required.
9 Evaluate In-core &/or Core Exit As indicatad in the DLC Response Thermucouples in ICC Det. Sys. per of 12/31/80 to NUREG 0737 Item Attach. 1 II.F.2, pars., 9.1, this evaluation will be performed and recommended changes will be submitted to the NRC on July 1, 1981.
10 Human Factors Analysis should be To be met.
The final design performed to determine:
layout will be based on human factors analysis for locations (a) Types of displays of Displays and Alarms for the (b) Types of Alarms types of displays and alarms (c) Locations of Displays design by W and considering the (D) Locations of Alarms criteria specified in this item.
Confirmation of Westinghouse Considering:
human factors analysis and alarms for their system will be obtained (a) Use during normal and abnormal or performed, if necessary.
plant conditions (b) Integration into Emergency Procedures..
o ITDi II.F.2 NUREG 0737 J
Inadequate Core Cooling Instrument System Evaluation Checklist : Design and Qualification Criteria for Pressurized f4ator i
Reactor Incore Thermocouple i
Conformance: Yes or No'(Specify Classification Ref. No., Page No., Para. No.,
Item No.
or Explanation & Justification (Page No.)
Requira. ment for Planned Actions)
Jo (cont.)
(c) Integration into Operator Training (d) Other Alarms Occurring (e) Need for Prioritization of Alarms t
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ITEM II.F.2 NUREG 0737 Inadequate Core Cooling' Instrument System Evaluation Checklist Appendix B: Design and Qualification Criteria for Accident Monitoring Instrumentation Conformance: Yes or No (Specify Classification Ref. No., Tage No., Para. No.,
Item No.
or Explanation & Justification (Page No.)
Requirement for Planned Actions)'
1 Instrument Environmentally Qualified Yes.
R.G. 1.89 Invokes IEEE 323-1974 IAW R.G.l.89 (NUREG 0588) y indicates equipment will meet IEEE 323-1974 except for Microprocessor and Display (Ref. 4)
(a) Seismic Portion per R.G. 1.100 Yes.
R.G. 1.100 Invokes IEEE 344-1975 when used with R.G. 1.89.
W indicated equipment will meet IEEE 344-1975 (Ref. 4).
(b) Extended Range Instrumentation (as identified in R.G. 1.97):
(1) Qual. Environment - Design To be met.
Final installation
)
Basis Accident in FSAR design requires some instruments to be installed outside containment and outside high energy break areas (Ref. 2, para. 2.3)
(2) Monitored variable rangc Yes.
R.G. 1.97 requires top of l
equal to Max. Range per R.G.
vessel to bottom of core.
(See 1.97 Part I Clar. It. 6)
(3) Computer Req'ts (See Part I, Clar. It. 8) 2 Single Failure (No single failure of Yes.
(Ref. 2, Table 4.1)
)
monitoring instrument, its aux, i
supporting features, or its power source, should result in loss of indication.
(a) Backup required if one channel Yes.
(Ref. 2, para. 4.5.5)
In results in ambiguity instances where ambiguity may result, E analysis concludes that core exit thermocouples should be checked, i
(b) Redundant Channels:
Yes.
(Ref. 2, para. 4.2.2.3)
(1) electrically independent Yes.
System is designed to meet IEEE-384-1977 (Ref. 2, para. 2.4)
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ITEM II.F.2 N;' REG 0737 Inadequate Core Cooling Instrument System Evaluation Checklist Appendix B: Design and Qualification Criteria for Accidert Monitoring Instrumentation Conformance: Yes or No (Specify Classification Ref. No., Page No., Para. No.,
Item No.
or Explanation & Justification (Page No.)
Requirement for Planned Actions) 2 (cont.)
(2) Class 1E Power Source Yes.
(Ref. 2, Table 4.1)
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(3) Physically Separated per Yes.
(Ref. 2, para. 2.4)
R.G. 1.75 up to any isoittion Compliance with R.G. 1.75 is device specified.
(4) At least one channel displayed Yes.
(Ref. 2, Table 4.1 & para.
on a direct-indicating or 4.2.2.3)
" Redundant displays are recording device.
provided for the two sets...The System includes... strip chart recorder."
3 Class lE Power Source energizing Yes.
(Ref. 2, Table 4.1) instrument 4
Instrument Channel Available prior to Yes.
See response to criteria accident (except per para. 4.ll IEEE-279 6 and 10 below.
5 QA recommendations of R.G's should be No.
System is generically designed followed to meet 10 CFR 50 Appendix B (Ref.
2, para. 2.4).
Plant specific (a) 1.23 design and installation will also (b) 1.30 be in accordance with 10 CFR 50 (c) 1.38 Appendix B and approved DLC (d) 1.58 Operations QA Program. No other (e) 1.64 action is planned.
(f) 1.74 (g) 1.88 (h) 1.123 (1) 1.144 (j) Task RS 810-5 6
Continuous indication (Instrument Yes.
Indication will be contin-overlap, if required) uous as described in ref. 2, para.
4.4.
Note that there is d/p detector overlap which is pro-vided for additional accuracy while venting the head (Ref. 2, para. 4.4)
ITEM II.F.2 NUREG 0737 Inadequate Core Cooling Instrument System Evaluation Checklist Appendix 3: Design and Qualification Criteria for Accident Monitoring Instrumantation Conformance: Yes or No (Specify Classification Ref. No., Page ho., Para. No.,
Item Nc.
or Explanation & Justification (Page No.)-
Requirement for Planned Actions) 7 Recording of Instrument Readout--
Yes. Trend information is included where trend information essential.
in microprocessor and display (Intermittent displays permissible if design (Ref. 2, para. 4.2.2.3, no transient information to be lost) 4.2.2.2.3.1, 4.5.3.1 & Fig. 4-5b).
Also the system includes digital I
to analog converters to provide three analog signals for a single three-pen strip chart recorder (Ref. 2, para. 4.4 & 4.4.2.3).
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Instruments Specifically Identified Yes.
(Ref. 2, Table 4.1).
t on Control Panels so operator can easily discern their use under accident conditions.
9 Isolation Devices for accident To be met.
Westinghouse indicates monitoring signals should meet qualification of ' electronic iso-requirements.
lation devices are included.and that Plant SpeciTic design must permit access (Ref. 2, para. 2.3) 10 Operational Availability Checking Yes.
System meets R.G. 1.22 provided for during Reacter Operation
" Periodic Testing of Protection System Actuation Functions (Ref. 2, para. 2.4) 11 Servicing, testing and calibrating To be met.
Such programs are being programs to maintain instruments are developed by Westinghouse as required indicated in Ref. 2, para. 4.3 i
12 Design should facilitate Admin.
Yes.
See response to item 13.
Control of Access to removal means 13 Design should facilitate Admin.
Yes.
Since remote display at Control of Access to set points and control board will indicate oper-adj us tments ator disabled inputs (Ref. 2, para. 4.1.1.3.1), this criteria is considered met. i L
ITEM II.F.2 NUREG 0737 Inadequate Core Cooling Instrument System Evaluation Checklist Appendix B: Design and Qualification Criteria for Accident Monitoring instrumentation Conformance: Yes or No (Specify Classification Ref. No., Page No., Para. No.,
Item No.
or Explanation & Justification (Page No.)
Requirement for Planned Actions) 14 Monitoring Instrument Design should Yes.
(See response to item 15 minimize conditions that would cause below and to Clar. It. 1 & 4 in metera, alarms, etc. to give confusing Part I) indications 13 Design should facilitate recognition, Yes.
(Ref. 2, para. 4.2.2.3) location, repair replacement,.or "Information displayed is intended adjustment of malfunctioning compo-to be unambiguous and reliable to nents.
minimize potential for operator error or misinterpretation...Any error conditions such as out of range sensors or hydraulic isola-tors are automatically displayed on the affected measurement."
16 Instrumentation inputs should be from Yes.
Inputs are from d/p trans-sensors measuring.the variable (to sitters which are very basic extent practical) technique for liquid level measure-ment. Other inputs are required to achieve desired indication accuracy (Ref. 2, para. 4.1 & 4.2) 17 Instruments should be used for both Yes.
"Each train of the RVLIS is normal and accident monitoring (to capable of monitoring coolant mass extent practical) in the vessel from normal operation to a condition of complete core uncovery." (Ref. 2, para. 4.4) 13 Periodic Testing per R.G. 1.118 No.
R.G. 1.118 invokes IEEE 338-1977 with comments. Periodic Testing of the system is being designed to IEEE-338-1971 (Ref.
2, para. 2.4).
No further action is planned.