ML18044A847
| ML18044A847 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 05/06/1980 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| TASK-15-16, TASK-RR NUDOCS 8005080387 | |
| Download: ML18044A847 (8) | |
Text
consumers Power company General Offices: 212 West Michigan Avenue, Jackson, Michigan 49i:I01
- Area Code 517 788-0550 May 6, 1980 Director, Nuclear Reactor Regulation Att Mr Dennis M Crutchfield, Chief Operating Projects Branch No 5 US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT "'.'
RESPONSE TO SEP TOPIC XV-16 "RADIOLOGICAL CONSEQUENCES OF 'SMALL LINES CARRYING PRH1ARY COOL.A.NT OUTSIDE CONTAINHENT" s oososo?~
Consumers Power Company was requested to provide additional information in NRC letter, "Radiological Consequences of Small Lines Carrying Primary Coolant Outside Containment," dated February.19, 1980.
A request for clarification of Item 1 was made from Mr J L Kuemin (Consumers Power Company) to Mr TR Quay (NRG) by telephone on April 15, 1980.
It was agreed that the review would include small lines (interpreted to include lines 4 inches and smaller) penetrating containment which carry primary coolant.
Therefor.e, the letdown and charging system,. the reactor coolant sample system, the primary coolant pump bleed-off system, the primary s*ystem drain tank pump suction, and the containmer.t. sump drain lines were reviewed.
Consumers Power Company's responses to Items 1 through 5 of the February 19, 1980 NRG letter are attached.
The responses for Items 6 through 9 are the same for all systems that were reviewed and are summarized as follows:
Item 6 The plant areas (where breaks might occur) which are served by ventilation systems which use cparcoal filters.
Response to Item 6 The Palisade~ Plant has three charcoal filtration units, none of which are associated with ventilation systems for the above-mentioned systems.
The three units serve the control room, fuel* handling area an.d the containment
. purge system.
Item 7 Whether the filters identified in 6, above, are used when the plant is at power.
Response to Item 7 This information is not applicable, based on the response to Item 6.
Item 8 Information concerning the charcoal filters, if used (ie, thickness, etc).
Response to Item 8 This information is not applicable; based on the response to Item 6.
Item 9 Are any plant areas where the breaks might occur completely closed?
Response to Item 9 There were not any completely closed areas identified at the Palisades Plant where breaks might occur.
David P Hoffman Nuclear Licensing Administrator CC JGKeppler, USNRC NRG Resident Inspector-Palisades Attachment 6 Pages 2
.. \\
.CHMEHT TO RESPONSE FOR PALISADES PLANT SEP TOPIC XV-.16 1
Item 1.
LETDOWN SYSTEM Item 2.
Item 3.
Item 4.
Item 5.
P & ID M-202 Containment penetration 36 Line Size; 3 inch Flow Rate; 120 gpm max based on flow through the three letdown orifices rated capacity of 40 gpm ea.
Plant location where lines traverse and/or terminate; Rooms 100 (Volume Control Tank), 106 (Pipeway), 121B (Boronometer and Process Monitor), 153 (Purification Filter), and 231 and 232 (Radwaste and Volume Control Filters).
Detection and Isolation capabilities, assuming a break occurs at any location outside containment; For a break it is expected the flow would increase and the pressure would drop in the system.
Additionally the temperature would increase due to high flow.
High temperature at the outlet of the regenerative heat exchangers will automatically isolate the letdown line via CV-2001.
High temperature alann is at 46o°F and isolation occurs at 470°F.
Automatic isolation of the letdown orifice bypass valve will occur on high flow (160 gpm).
The high flow alann is also 160 gpm.
High temperature downstream of the letdown heat exchanger (at 130°F) signals CV-2023 to bypass the ion exchangers and alanns in the control room.
Breaks down-stream of the containment isolation valve CV-2009 can be manually isolated via that valve.
There are additionally several other valves that can be closed both inside and outside containment to isolate leakage from breaks outside containment.
These except for the automatic functions mentioned above, require manual action.
Besides the high temperature and high flow alarms previously mentioned, breaks downstream of the volume control tank would likely result in a low level and low pressure alarm in the control room.
9*
2 Palisades Plant Item 1.
CHARGING SYSTEM Item 2.
Item 3.
Item 4.
Item 5.
P & ID M-202 Containment Penetration 45 Line Size; 2 inch Flow Rate; 133 gpm through letdown system based on flow rate of all three charging pumps.
Plant location where lines traverse and/or terminate; Rooms 104 A & B ( Cha.rging Pumps ), and 106 (Pipeway)
Detection and Isolation capabilities; The detection and isolation capabilities discussed for.the letdown system are applicable to breaks at the charging pump suction. Additionally, breaks can be detected as a result of a low discharge flow and/or low discharge pressure alarm.
A charging pump trip will also occur on low suction pressure which would result from a break on the suction side piping.
A break in the discharge line downstream the containment isolation check valve may also result in high temperature from the letdown side of the regenerative heat exchanger which would automatically isolate the letdown system while the containment side check valve would isolate the charging system line.
Item 1.
REACTOR COOLANT SAMPLE P & ID M-219 Containment Penetration 21 Item 2.
Line Size; ~inch to sample station.
3 Palisades Plant Item 3.
Flow Rate; 50 gpm assuming a pressure drop in the ~ inch line of 2500 psig.
Item 4.
Plant locations where lines traverse and/or terminate; Room 228 (sample room outside personnel lock area), 100 (Volume Control Tank), 106 (Pipeway), 103 (Controlled Chem Lab drain tank), 120 (Degassi-fier pump room), and 121B (Boronometer Room).
Iteni. 5.
Detection and Isolat~on Capabilities; Sampling is controlled administratively by procedure.
The procedure states the sample system piping should be flushed from five to fifteen minutes prior to drawing a sample.
The flush is usually routed to the Volume Control Tank while the sample sink drain is routed to the Controlled Chem Lab drain tank.
A break in the sample line in the vicinity of the sample station would be terminated by closing the sample solenoid valve inside containment. *This action would be accomplished by the technician taking the sample.
The probability of failure in this system is very remote due to the periodic and short time period the system is in operation..
4 Palisades Plant Item l.
PRIMARY COOLANT PUMP BLEEDOFF Item 2.
Item 3.
Item 4.
Item 5.
P & ID M-202 Containment penetration 44 Line Size; 3/4 inch Flow Rate; 60 gpm based on maximum flow through the four excess flow check valves which close at 15 gpm.
Plant locations where line traverses and/or tenninates; Room 602 (Pipeway)
Detection and Isolation capabilities; There are no automatic means of detection.
The excess flow check valves will isolate the line if large flows are experienced.
Manual isolation can be accomplished by CV-2083 which is located outside containment.
5 Palisades Plant Item l. PRIMARY SYSTEM DRAIN TANK PUMP SUCTION P & ID M-210 Containment Penetration 47 Item 2.
Line Size; 4 and 3 inch Item 3.
Flow Rate; 150 gpm based on runout flow of one prima!"J system drain tank pump.
Item 4.
Plant location where lines traverse and/or terminate; Rooms 106 (Pipeway), 117 (Pump Room), 118 (Receiver Tank Pumps),
120 (Degassifier Pump), 153 (Volume Control Demineralizer),
154 (Radwaste Demin), 227 (Vacuum Degassifier), 230 (Radwaste Filter).
Item 5.
Detection and Isolation Capabilities ;-
The pumps are not normally in operation and are initiated by high level in the drain tank.
During plant operation virtually all of the water in the tank comes from the primary coolant pump s.eal leakage.
So the amount of time that primary coolant is being pumped outside containment to Radwaste or back into containment to the clean waste tanks is very.short.
Normally two to three operations per day.
Like the sample system, the operation is periodic and for a short period of time limiting the likelihood of a break in the piping.
Detection of a break should it occur could be via the low level alarm on the drain tank.
Isolation would be manually initiated by closing the containment isolation valves CV-1002 and/or CV-1007.
Item 1.
CONTAINMENT - SUMP DRAIN P & ID M-211 Containment Penetration 52 Item 2.
Line Size; 4 inch 6
Palisades Plant Item 3.
Flow Rate; Gravity feed from sump tank to dirty waste drain tank, elevation head is maximum of 9.5', based on one foot level in sump and low point in ~cop seal.
Flow rate is maximum of 250 gpm.but drops as head drops and ends when sump is emptying.
Item 4.
Plant location where lines traverse and/or terminate; Rooms 1, lA, & lB, Dirty waste drain tank and pump rooms.
Item 5.
Detection and Isolation Capabilities; The isolation valves CV-1103 and 1104 are nonnally shut and are normally opened on a high level. in _the __ sump tank at 4".
High - High level is reached at one foot which is 28.6% of total height of tank.
A break is very remote due to the periodic use and very low pressure in the line.
A break would at most drain the sump which is normally fed from the CRDM seal leakoff.
Overflow from the primary system drain tank is sometimes routed to the containment sump also.
The volume of water to the 4 inch high level set point is 950 gal. and to the l' set point is 2850 gal.