ML19221A570
| ML19221A570 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/01/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| OLP-790401, NUDOCS 7905230216 | |
| Download: ML19221A570 (6) | |
Text
v FAo Letter frem E. F. Dowling to E. A. Womack d ated A,ril 1, 1979 subject Instrumentation status General observation of instrument status 1.
Flow, level and pressure transmitters are expected to fail at some point due to two mechanisms.
(a) high radiation or (b) submersion in water 3
2.
Radiation levels (estimated at 10 rad /hr) chould start to effect BY transmitters some time after 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> on 4/1/79 (integrated dose 105 rad.)
Degradation should be cradual with time, until the inte-rated 6
7 6
7 rads (10 is to + 41.7 days: 10 equal dose reaches 10 to 10 to + 417 days) at which time the transmitter will cease to function.
Calculation o' vater level in the Reactor Building indicates that a large number of cransmitters are submerged and have been for a number of days.
Few failures have been reported.
The transmitters are sealed and have been qualified by tests te high temperature, pressure and steam conditions (2860F, 60 psig), but have not been tested for submersion in water.
There is no way to predict how long the submerged transmitters will continue to function.
4.
Transmitter failure is expected to be by increase in noise level, gross deviation from redundant indications and finally loss of signal.
Attachmen:
shcws which transmitters are vulnerable due to location above bui g floor and by virtue of radiation resistance.
Attachment 2 defines oiternative ways to obtain parameter measurements.
This attachment will be updated when additional information'is available.
79052302l4
/
~
C-F 105 Rads Level (Water Volume)
BY (Bldg Elevation)
Transmitter 107 Rads
?R7' 6"
Strine No.,
Parameter Foxboro 2'-5" 179,630 gal.
SP6B-PTl SGB Pressure 3'-0" 222,990 RCl4A-DFI-3 & 4, Loop A RC Flow 3'-6" 260,155 RCl-LT 1,2 & 3, Press.
SP6B-PT 2 SGB Pressure Level RCl4A-DPT 1 & 2, Loop _A RC 22 - PT 1 thru 8 RC Flow Reactor Coolant Pump Seal Cavity Pressure RCl4B-DPT 3 & 4, Loop B RC Flow Note:
This group may be located at this SP1A-LT 2 & 3, SG A Operate level or the next level Level higher SPlA-LT 4 & 5, SGA Start up Level SPlB-LT 1, ElB Full Range Level SPlB-LT 2 & 3, SGB Operate Level SP1B-LT 4 & 5, SGB Startup Level 5'-2" 384,038 SP1A-LTl, SCA Full Range SP6A-PT 1 & 2 Level SG-A Pressure RC3A-PT 3 & 4 RC Pressure Wide Range RC3A-PT 5 RC Pressure Low Range RC3B-PT 3 RC Pressure Wide Range Assumption:
5 1)
BY transmitter will begin to fail about 10 Rad.
- 2) Foxboro transmitter will begin to fail above 10' Rad.
- 3) Transmitters have been receiving 1000 R/hr.
4)
Both BY and Ecxboro transmitters may fail if submerged in water.
5) w'ater height is related to volume by 1 ft, per 74,330 gallons.
164 337
Att chment 2 Measurement Alternative Primary Source Alternate Source Reference Backup Parameter of Measurement of Measurement Sheet RC Pressure RC3A-Pr 3&4 RC22-PT 1 thru 8 Note: Temperature (Wide) ESFAS vs saturation pressure RCP Seal Cavity via steam tables RC3B-PT 4 Pressure (wide) ESEAS RC2-TA 164 Pressurizer Temp.
CA-PI Pressurizer steam or water sample pressure.
RC Pump Vibration RC3A-PT 5 (low)
RC Pressure less than 500 RC Temperature Income T/Cs RC4A-TE 2&3, T~ot H
RC4B-TE 2&3, THot RCSA-T2 2&4, TCold RCSB-TE 2&4, TCold RC-TE9 RC4A-TE 1&4, TH RC4B-TE 1&4, TH RCSA-TE 1&3, TC RCSB-TE 1&3, TC RC15A-TEl, T 3 RCISB-TEl, TH RC15A-TE2, TC RC15B+TE2, TC RC15A-TE3, TC 164 338 RC15B-TE3, TC RC-TEll MU-TES Accounting for Coolant:
. Primary Source Alternate Source Reference Backup Parameter of Measurement of Measurement Sheet DH6-TE 162 SP3A-TE 1&2 Steam cen. Saturation Temperature AP3B-TE 1&2 Steam Gen. Saturation Temperature RC Flow Loop A RC14A RC Pump Motor DPT 1,2,3 & 4 Current RC Flow Loop B RC14B RC Pump Mo'.or DPI 1,2,3 & 4 Current SG Operating SP1A-LT 2&3 SG-A SP1A-LT 1 SG-A Level SP1B-LT 263 SG-B SPlB-LT 1 SG-B RC Temperature See RC Temp. Sheet SPLA-LT 4&5 SG-A SliB-LT 4&5 SG-B Feed Water Status Sample Lines as Level Indicators Press. Transmitter Across Feed Water Line and Main Steam Line SP3A-TE 162 SG-A Use one element as heating element by applying low voltage.
Other element will read different if element is covered or uncovered.
SP3B-TE 162 SG-B 164 339
. Primary Source Alternate Source Reference Backup Parameter of Measurement of Measurar Sheet SG Wide Range SPIB-LTl SG-B Sample line as Level level indication SPIA-LTl SG-A Pressurizer RCl-LT1,2&3 MU14-LT 1&2 Level (MU Tank Level)
MU7-DFT 1,2,3,4 (Scal injection flov) 1 MU4-DFT (Let-down flow)
Pressurizer Level Alter-nate Calcula-t iot. Procedure Procedure:
Sten 1 - Record let-devn flow at incurements using MU4-DFI Step 2 - Record RC pump seal injection flow at increments using MU7-DPT 1,2,3 & 4 Step 3 - Record MU tank level at increment using MU14-LT 1&2 Steo 4 - MU tank volume is 4388 gallons.
MU tank galls per inch - 31.
Pressurizer volume 11,230 gallons.
Pressurizer gallons per inch - 24.
Steo 5 - Determine volume of 1' :-down.
Item 1 x ::me increment = volume in gallons.
Step 6 - Determines volume of RC pump injection.
Item 2 x time increment Ste:p Z - Subtract result of Step 6 from result of Step 5.
Step 8 - S ibt: act previous MU tank level froa level determined at Step 3.
I64 340.
e.
Steo 9 - Multiply result of Step 8 by MU tank volume per inch given in Step 4.
S_tep 10 - Add or subtract the results of Step 9 to the results of Step 7.
Sinp 11 - Divide the result of Step 10 by pressurizer gallons / inch to obtain the change in pressurizer level.
Assumotions:
~
1.
Only source of make up is to RC pump seal.
2.
No nC leakage other than let down.
3.
Constant RC pressure (Procedure can be modified to accommodate varying RC pressur e) 164 34,
.