ML19338G656
| ML19338G656 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 10/28/1980 |
| From: | Sylvia B VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 872, NUDOCS 8010310468 | |
| Download: ML19338G656 (21) | |
Text
._.
r VI N G I N I A E r.E C*T H I C A N I) I'Ow H H CO M 1% NY llICIIM OM13,VIHGIN 1 A 2:Bu 61 October 28, 1980 Mr. Harold R. Denton, Director Serial No. 872 Of fice of Nuclear Reactor Regulation N0/RMB:ms Attn:
Mr. Robert A. Clark, Chief Docket Nos. 50-338 Operat.ing Reactors Branch No. 3 50-339 Division of Licensing License Nos. NPF-4 U. S. Nuclear Regulatory Commission NPF-7 Washington, D. C.
20555
Dear Mr. Denton:
MULTIPLE STRUCTURE ARS CONCERN NORTH ANNA POWER CTATION UNIT NOS. 1 AND 2 This letter is written in response to a verbal request for additional information concerning the Multiple Structure ARS Evaluation being performed on North Anna Unit No.
1.
The verbal request was made via a telephone conver-sation on October 17, 1980 between Vepco and NRC staff members.
In general, l
members of the NRC staff requested the following:
1.
Clarification of tha brase " moderate increase" used in our letter to the NRC dated E.
ember 26, 1980 giving the Phase I results on North Anna Unit No. 1, and the basis for acceptability.
2.
Status of the Phase II evaluation to date stating what systems we have determined acceptable using an envelope ARS criteria.
3.
Development of a priority list for the Phase II evaluation and a schedule for completion according to priorities.
1 Our response to the above request for additional information is as follows:
1.
In order to clarify our usage of the phrase " moderate increase" in our letter Serial No. 685 dated September 26, 1980, we provide the following discussion:
1 The level of response increase for the eleven systems listed on page 3 of Table 1 ranged between approximately 5% and 40%.
The use of the phrase " moderate increase", however, was not intended to imply that the eleven systems were accepted on the basis that the increase was only " moderate". The basis of acceptability was that the stress levels at all points in the piping remain below the applicable ASME code allowables and that the system supports and equipment are capable of accepting the increased loading.
8010310 M
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Mr. Harold R. Denton 2
VamoxxA EttcTklC AND PowEss COMPANY TO
- 2. provides the status of various Category B items at this i
time.
The data is preliminary and in some cases only pa rt ial res ul t', are available, i.e.,
pipe stress but not pipe support eval-uations have been completed.
Problems for which pipe stress levels have been determined to be satisfactory with an enveloped run indicated in the status list.
1
- 3. provides an integrated priority list of the systems requiring further analysis by computerized methods.
The grouping i
categories 1 through 8 are listed in order of decreasing priority.
l The priority list includes stress problems for both Units 1 and 2.
Based on your concerns with regard to the schedule for completion 3
given for Unit No. 1 in our letter Serial No. 685, we are in the i
process of rescheduling the Phase II evaluation to reflect the l
priorities given in Attachment 2.
A revised schedule showing target i
completion dates for each priority group will be forwarded to you in j
a separate letter as soon as possible, j
As stated in our previous correspondence on this matter, if at any time during the Phase II effort, results obtained clearly show that a design of a particu-lar piping system or support cannot be justified against the concept of multiple structure ARS input, the system will be reviewed per Technical Speci-
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fication requirements and appropriate corrective action will be taken.
Should you require any additional information, please contact us.
Very truly yours,
[
B. Rf Sylvia Manager - Nuclear Operations and Maintenance cc:
Mr. B. Joe Youngblood, Chief Licensing Branch No. 3 Division of Licensing j
Washington, D. C.
20555 Mr. James P. O'Reilly, Director Office of Inspection and Enforcement j
Region II Atlanta, Georgia 30303 i
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o ATTACIIMENT 1 This attachment provides status as of October 24, 1980.
1)
The following items were part of the Unit 1 initial r,-view and were reported in Vepco letter to the NRC number 510 of June 6,1980. These items were reported as category B items in Vepco letter to the NRC number 685 of September 26, 1980 as " requirine further evaluation" had been done. All are Unit 1 items.
MSK-104A Low Head Safety Injection MSK-104D Recirc Spray MSK-107B Safety Injection MSK-111C Safety Injection 2)
The following itan was the result of the parallel analysis being done by the NRC and S&W for the Unit 2 low head safety iniection pumps and has shown satisfactory results for an envelope ARS condition.
A MSK-104B Low Head Safety Injection 3)
The following represents preliminary and in some cases partial 4
analysis of Un:t 1 and 2 iteno.
Unit 1 MSK-101A Preliminary runs on CDC - NUPIPE indicates stresses within allowable.
Support and other evaluations continue.
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o 3) cont'd.)
Unit 1 MSK-102C NUPIPE coded in preparation for analysis MSK-102D Envelope run indicates allowable stress and acceptable supports for the safety related portions.
MSK-103B NUPIPE coded in preparation for analysis.
MSK-103AM NUPIPE coded in preparation for analysis.
t MSK-114E NUPIPE coded in prepartion for analysis.
MSK-114K NUPIPE coded in preparation for analysis.
MSK-118B NUPIPE coded in preparation for analysis.
MSK-121A NUPIPE coded in preparation for analysis.
3) cont'd.
Unit 1 SSR-7 NUPIPE coded in preparation for SA-7223 analysis SSR-7 NUPIPE coded in preparation for SA-7209 analysis SSR-7 All stresses wit' tin allowable for SA-7198 envelope run.
Reviewing supports and other conditions.
SSR-8 All stresses within allowable for SA-7217 an envelope run.
Continuing further evaluations.
)
SSR-8 All stress witin a allowable for SA-7234 envelope run. Reviewing supports and other conditions.
31 cont'd.)
Unit 2 MSK-101A NUPIPE coded in preparation for analysis.
MSK-101B NUPIPE coded in preparation for analysis.
MSK-101C NUPIPE coded in preparation for analysis.
MSK-101D NUPIPE coded in preparation for analysis.
MSK-102A NUPIPE coded in preparation for
)
analysis.
MSK-102B NUPIPE coded in preparation for analysis.
MSK-102C NUPIPE coded in preparation for analysis.
MSK-102D NUPIPE coded in preparation for analysis.
3)
Unit 2 MSK-114B NUPIPE coded in preparation for l
analysis.
MSK-114F Stresses within allowable for envelope run. Analysis continues.
MSK-114M Stresses withia alowable for envelope run. Analysis continues.
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i ATTACHMENT 2 i
GROUP 1 Near Reactor Coolant Pressure Boundary Unit 2 MSK-103BB 6" Low Head Safety Injection to cold leg in area cf valve manifold.
Away from loop by one check valve and intermediate anchor.
Inside reactor containment i
MSK-103BH Loop fill header to all loops - separated from loops by normally closed valve for each loop and an intermediate anchor.
Inside rea: tor y-containment.
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- - - _ _ - _ _ - _ _ = - -
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GROUP 2 Safety System-Accident Mitigation - Common Lines i
Unit 1 MSK-103R Cold leg safety injection to loops. Outside loops by two check valves.
Inside reactor i
containment.
1 MSK-103AC Low head safety injection to loops. Outside loops by two check valves.
Inside reactor i
containment.
L Unit 2 MSK-103BD Cold leg safety injection to loops.
Outside j
loops by two check valves.
Inside reactor containment.
I i
(11715)
MSK-111C Suction manifold for charging /high head safety injection pumps.
Outside containment.
MSK-103AA Low head safety injection to loops. At penetration area.
Outside loops by two check valves.
Inside reactor containment.
1 i
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GROUP 3 Safety Systems-Accident Mitigation-One line per trai'.1-multiple trains involved Unit 1 MSK-114F Outside recirc spray pump A discharge.
to D recirc spray cooler.
Inside reactor containment.
MSK-114K Outlet of "B" recirc spray cooler to spray header.
Inside reactor containment.
MSK-114L Outlet of "A" recirc spray cooler to spray header.
Inside containment.
I MSK-114M Outlet of "C" recirc spray cooler to spray header.
Inside containment.
SSR-7 Seal water injection to "A" reactor coolant SA-7223 pump. At penetration area separated from pump by a check valve and an intermediate anchor.
Inside reactor containment.
SSR-7 Seal water injection to "B" reactor coolant SA-7209 pump. At penetration area separated from pump by a check valve and an intermediat.e anchor.
Inside reactor containment.
n.
l GROUP 3 (cont'd.)
Unit 1 SSR-7 Seal Water injection to "C" reactor coolant SA-7198 pump.
At penetration area separated from f
pump by a check valve and an intermediate anchor.
Inside reactor containment.
4 h
Unit 2 MSK-107E Two separate pipes for discharge of "A" and "B" low head safety injection to high head safety injection. Outside containment.
I MSK-105A Service water supply to reactor containment.
Outside containment.
MSK-105B Service water return frea reactor containment.
Outside containment.
1 l
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GROUP 4 Safety System - Accident Mitigation - One line per train.
Only one train or one half system function involved. Other train or half system is category A.
Unit 1 MSK-111B Discharge of "A" low head safety injection to high head safety injection. Outside con-tainment.
MSK-114E Discharge of "A" quench spray pump to the spray header.
Inside reactor containment.
Unit 2 MSK-111B Discharge of "A" low head safety injection pump to the high head safety injection pumps.
7 Outside reactor containment.
MSK-114B Discharge of "B" quench spray pump to spray header.
Inside reactor containment.
MSK-107H Discharge of "B" quench pump to the containment.
Outside reactor containment.
MSK-104E Discharge of "A" and "B"outside recirc spray pump to penetration two problems. (Flows ultimately through "D" and "C" recirc spray cooler respectively). Outside reactor contain-i ment.
i
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GROUP 4 (cont'd.)
Unit 2 MSK-104F Discharge of "B" quench spray pump at i
penetration. Outside reactor containment.
l MSK-114D Outlet of "D" recirc spray cooler to spray header.
Inside reactor containment, e
j MSK-114F Discharge of "A" outside recirc spray pump to "D" recirc spray cooler.
Inside reactor i
cor.tainment.
]
j MSK-114M Outlet of "C" recirc spray cooler to spray header.
l 1,
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GROUP 5 Secondary Plant Systems Unit 1 MSK-101A Main steam from penetrations to turbine.
Outside reactor containment.
MSK-101B Main steam fro "A" steam generator to penetration.
Inside reactor containment.
MSK-102C Feedwater from penetration to "C" steam generator.
Inside reactor containment.
MSK-102D1 Feedwater to the containment from the manifold. Outside reactor containment.
L Unit 2 MSK-101A Main steam from penetration to the turbine.
Outside reactor containment.
MSK-101B Main steam from "A" eteam generator to the penetrations.
Inside reactor containment.
MSK-101C Main steam from "B" steam generator to the penetrations.
Inside reactor containment.
-e
GROUP 5 (cont'd.)
Unit 2 MSK-101D Main steam from "C" steam generator to the penetrations.
Inside reactor containment.
MSK-102A Feed water to "A" steam generator from penetration.
Inside reactor containment MSK-102B Feed water to "B" steam generator from penetration.
Inside reactor containment.
MSK-102C Feed water to "C" steam generator from r
Incide reactor containment.
MSK-102D1 Feed water to containment from the manifold.
Outside reactor containment.
MSK-103A6,A7 Individual steam generator blowdown lines at penetration from each steam generator.
Inside reactor containment.
l
GROUP 6 Cooling Water Systems Associated With Plant Cooldown Unit 1 MSK-103B Component cooling supply to "B" residual heat removed heat exchanger.
Inside Reactor Containment.
MSK-103E Component cooling return from "B" residual heat removal heat exchanger.
Inside reactor containment.
MSK-118C Component cooling main supply to containment.
Outside reactor containment.
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MSK-118D Component cooling main return from containment.
Outside reactor containment.
MSK-118K Component cooling main supply tc, Unit 2 containment. Outside reactor containment.
MSK-118N Main component cooling return from Unit 2 containment. Outside reactor containment.
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GROUP 6 (cont'd.)
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Unit 2 MSK-103F Component cooling supply to "A" residual heat i
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removal heat exchanger.
Inside reactor con-tainment.
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MSK-103G Component cooling supply to "B" residual heat removal heat exchanger.
Inside reactor i
l containment.
1 9
MSK-103L Component cooling,eturn from "A" residual heat removal heat exchanger.
Inside reactor
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containment.
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1 GROUP 7 Lines not associated with accident mitigation or plant cooldown 1
but part of normal reactor coolant inventory control system i
Unit 1 SSR-8 Combined seal water return header from reactor i
SA-7217 coolant pumps to penetration.
Inside reactor containment.
l 4
4 1
i Unit 2 MSK-111N Combined seal water return header from reactor l
coolant pump to penetrations.
Inside reactor containment.
l 4
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MSK-111Y Charging line from penetration to the re-i generative heat exchanger.
Inside reactor j
containment.
1 1
MSK-111AC Letdown at the penetration area.
Inside reactor containment.
1 i
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GROUP 8 Other lines with no accident mitigation function Unit 1 t!SK-103Af!
Component cooling supply to "C" reactor coolant pump.
Inside containment.
?!SK-118B Component cooling supply to "B" reactor coolant pump. Outside reactor containment.
I 1
tlSK-118F Component cooling return from "C" reactor i
coolant pump and all reactor coolant pump l
t thermal barrier.
Outside reactor containment.
?!SK-121A Component cooling supply to the fuel pool
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coolers. Outside reactor containment.
?!SK-121B Component cooling return from the fuel pool cooler. Outside reactor containment.
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GROUP 8 (cont'd.)
Unit 2 MSK-103BQ Instrument air suction from the containment.
Presently isolated.
Inside reactor contain-ment.
(11715)
MSK-111A/649 Borated water supply to the refueling water storage tank.
Outside reacter containment.
MSK-103C Component cooling supply to the "B" reactor coolant pump.
Inside reactor containment.
MSK-103D Component cooling supply to "A" reactor coolant pump.
Inside reactor containment.
MSK-103E Component cooling supply to "C" reactor coolant pump.
Inside reactor containment.
MSK-103J Component cooling return from "C" reactor coolant pump.
Inside containment..
I
7 GROUP 8 (cont'd.)
Unit 2 MSK-103K Component cooling return from "D" reactor coolant pump.
Inside containment.
(11715)
MSK-118G Chilled water return from Unit 2 recire air cooling coiling.
Outside reactor containment.
MSK-103A6/795 Component cooling at thermal barrier of reactor coolant pump thermal barrier.
Inside reactor containment.
(11715)
MSK-118B Component cooling supply to "B" reactor coolant pump. Outside reactor containment.
(11715)
MSK-118F Component cooling return from "C" reactor coolant pump and all reactor coolant pump thermal barrier.
Outside reactor containment.
I l
_. - _