ML13310A816
| ML13310A816 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/07/1983 |
| From: | Baskin K Southern California Edison Co |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TAC-44128, TASK-2.F.1, TASK-TM NUDOCS 8307110232 | |
| Download: ML13310A816 (13) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER OF NUCLEAR ENGINEERING, (213) 572-1401 SAFETY, AND LICENSING July 7, 1983 Director, Office of Nuclear Reactor Regulation Attention:
Mr. D. M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 NUREG-0737, Items II.F.1.4, II.F.1.5, II.F.1.6 Post-Implementation Review San Onofre Nuclear Generating Station Unit I
References:
- 1. Letter, D. M. Crutchfield, NRC, to R. Dietch, SCE, NUREG-0737, Item II.F.1.4 Containment Pressure Monitor, Item II.F.1.5 Containment Water Level Monitor, Item II.F.1.6 Containment Hydrogen Monitor, January 6, 1983
- 2. Letter, R. W. Krieger, SCE, to D. M. Crutchfield, NRC, NUREG-0737, Items II.F.1.4, II.F.1.5, II.F.1.6, Post-Implementation Review, May 10, 1983 Reference 1 provided us with a request for additional information on the subject post-TMI requirements to enable you to complete your review.
Submittal of this information to you, as established by Reference 2, is scheduled for July 1, 1983. Accordingly, the purpose of this correspondence is to provide you with the requested information.
Provided as an enclosure to this letter is the information requested in Enclosures 1 and 2 of Reference 1. As indicated in Item (2e) of 8307110232 830707 PDR ADOCK 05000206 P
Mr. D.
July 7, 1983 Enclosure I to Reference 1, you will compute the overall system time response. The information in the enclosure to this letter should satisfy your request.
If you have any additional questions regarding this subject, please let me know.
Very truly yours, Enclosure
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ON NUREG-0737 ITEMS II.F.1.4 Containment Pressure Monitor II.F.1.5 Containment Water Level Monitor II.F.1.6 Contaiment Hydrogen Monitor
Reference:
Letter and Enclosures 1 and 2, D. M. Crutchfield, NRC, to Robert Dietch, SCE, NUREG 0737 Items II.F.1.4, 5 & 6, dated January 6, 1983 The following information and data is submitted in response to the NRC's request made in the referenced letter.
The format of this response corresponds to that of "Enclosure 1" of the referenced letter.
(1) Exceptions Being Taken to NUREG-0737 Requirements At this time we do not plan to take any exceptions to NUREG-0737 requirements. However, the environmental qualification requirements are being addressed on a schedule indicated to you by letter dated May 6, 1983.
(2a) Explanation of Pressure Monitoring System (PMS) Block Diagram The block diagram shows one PMS instrument loop. Recording capability is provided via the Technical Support Center (TSC) Accident Monitoring Systems (AMS) computer.
There is a second identical independent PMS instrument loop which provides continuous indication in the control room. However, the second loop does not provide an input to the AMS computer for providing recording capability.
F~~LP rl-COMP-0tL. FMMorc mo2~-:fl-t~o1 MOVF-L: rl?.AI-It2V move&L: 9210 16L'E-A-foPA AadOI0rlf rrfli:
OXtSofjo rrli f~rife mTO 091'MA V f1U M Pte)(F4
- Yrv51frrn (IAr1-)
mf~rA* riox~orio COMPuiV3 MOM'. S-tJMrA mPA: P0000rM HA~itComtlE'O Oz2 a)
LoCV, UIAC-rArr1
-3 (2b)
Uncertainties in Containment Pressure Indication NUREG-0737, Item II.F.1, Attachment 4 Uncertainties are expressed as One Standard Deviation and as a
percentage of full range.
Transmitter Random Bias (+ 0.5% of Span)
+ 0.17%
(This figure envelopes the uncertainties due to repeatability, hysteresis, deadband, reproducibility and drift).
Transmitter Supply Voltage Effect (+ 0.1% of Span
+ 0.033%1 for 10% change in voltage)
Transmitter Ambient Temperature Effect
+ 0.33%
(+ 1.0% of Span)
Transmitter Output Shif due to Accident
+ 2.0%
Radiation Dose TID.2 x10 rad (gamma) (+ 6%)
Transmitter Output Shift due to Extreme
+ 0.33%
Services Conditions (+ 1%)
Transmitter Output Shift After Seismic
+ 0.33%
Transmitter Output Shift due to Thermal
+ 0.67%
Aging (i.e., at End of Life) (+ 2%)
Current to Voltage Converter Random Bias
+ 0.083%
(Accuracy + 0.25% of Span)
Current to Voltage Converter
+ 0.0671 Supply Voltage Effect (less than + 0.2% of span for
+ 5% voltage variation)
Current to Voltage Converter
+ 0.17%
Ambient Temperature Effect (less than 0.5% of span for 250 C change)
Isolator Random Bias (Accuracy + 0.5% of Span)
+ 0.17%
Isolator Supply Voltage Effect
+ 0.17%1
(+ 0.5% for + 5% change in dc supply)
Isolator Ambient Temperature Effect (+ 0.5% of Span
+ 0.17%
for 250C change)
Indicator Random Bias (Accuracy + 1.0% of Span)
+ 0.33%
Supply Voltage expected to vary less than + 0.5%
-4 Indicator Ambient Temperature Effect (+ 0.03% per oC;
+ 0.25%
250 C Change)
Indicator Supply Voltage Effect (+ 0.05% per 1% of
+ 0.17%
line change; 10% line change)
Indicator Uncertainty due to Reading
+ 0.17%
by Operator (+ 25% of Smallest Division)
Universal Field Multiplexer (UFM) Accuracy
+ 0.033%
(+ 0.1%)
UFM Linearity
+ 0.017%
(+ 0.05%)
UFM Repeatability
+ 0.0083%
(+ 0.025%)
(2 c) Overall System Uncertainty Containment Pressure Indication
- 1. Indicator Uncertainty S (total system, bias, etc.) = S (s,b)
S (s,b) = [4(.17)2 + (.033)2 + 4(.33)2 + (2)2 + (.67)2 + (.083)2 + (.067)2 + (.25)2] 1/2
= [5.075] 1/2
= 2.25%
- 2. Accident Monitoring System Computer Printout of Containment Pressure S (s,b) = [5(.17)2 + 2(.033)2 + 3(.33)2 + (2)2 + (.67)2 + (.083)2 + (.067)2 + (.017)2 + (.0083) 2] 1/2
= [4.934] 1/2
= 2.22%
(2d) Module Time Responses Containment Pressure Indication Pressure Transmitter Time Constant
=.48 Current to Voltage Converter Time Constant
=.026 Isolator Time Constant
=
.069 Indicator Time Constant
'=
.125 Universal Field Multiplexer (UFM) input signals are scanned, linearized and stored in the UFM Random Access Memory (RA4) on a once per second basis.
(2 e) NRC will compute Overall System Time Response
-5 (3 a) Explanation of Water Level Monitoring System (WLMS) Block Diagram The block diagram is representative of one WLMS instrument loop.
Recording capability is provided for one narrow range and one wide range WLMS instrument loop via the TSC AMS computer.
A second identical independent narrow range and wide range WLMS instrument loop provide continuous indication in the main control room; however, no recording capability is provided for the second loops.
The level element for the two wide range WLMS instrument loops each consist of these separate level elements which are electrically interconnected to cover the wide range requirement.
Each narrow range WLMS loops utilizes only one level element to monitor the contaiment sump.
~LP {uuuIrl cioJ1ML Aoott 3IP IIl LMVAt (Lgm Mnf,
Or TN U1Q I CAfO r
~MF:
fwf5 iR crl~ rii: roxoo C:, 16 A MOR'rfAOM t TL WA rflrif ~ilm Copig~orA OcoPpu~or4i (sa)c-sAoc i
WA-g~3Le'JL-otlI-ro~at-c 5yo-fir (wLmn)
-7 (3b) Uncertainties in Containment Water Level Indication NUREG 0737, Item II.F.1, Attachment 5 Uncertainties are expressed as one standard deviation and as a
percentage of full range.
Level Element Non-Accumulative Accuracy (Q 1/2 inch)
Narrow Range
+ 0.23%
Wide Range
+ 0.067%
Level Element Installation Tolerance (+ 1/4 inch)
Narrow Range
+ 0.12%
Wide Range
+ 0.032%
Level Transmitter Random Bias
+ 0.083%
(Accuracy + 0.25%)
Current to Voltage Converter Random Bias
+ 0.083%
(Accuracy + 0.25% of Span)
Current to Voltage Converter Supply
+ 0.067%1 Voltage Effect (less than + 0.2%
of span for + 5% voltage variation)
Current to Voltage Converter
+ 0.17%
Ambient Temperature Effect (less than 0.5% of span for 250 C change)
Isolator Random Bias (Accuracy + 0.5% of span)
+ 0.17%
Isolator Supply Voltage Effect
+ 0.17% 1
(+ 0.5% for + 5% change in dc supply)
Isolator Ambient Temperature Effect
+ 0.17%
(+ 0.5% for 250 C change)
Indicator Random Bias
+ 0.33%
(Accuracy + 1.0% of span)
Indicator Ambient Temperature Effect
+ 0.25%
(+ 0.03% per oC; 250C change)
Indicator Supply Voltage Effect
+ 0.17%
(+ 0.05% per 1% line change; 10% line change)
Indicator Uncertainty due to Reading
+ 0.17%
by Operator (+ 25% of Smallest Division)
-8 Universal Field Multiplexer (UFM) Random Bias,
+ 0.033%
(Accuracy + 0.1%)
UFM Linearity (+ 0.05%)
+ 0.017%
UFM Repeatability (+ 0.025%)
+ 0.0083%
(3 c) Overall System Uncertainty Containment Water Level Indication
- 1. Narrow Range Indicator S (s,b) = [(.23)2 + (.12)2 + 2(.083)2 + (.067)2 + 3(.17)2 + (.33)2 + (.25)2] 1/2
= [.3437] 1/2
=.59%
- 2. Narrow Range Water Level Accident Monitoring System Computer Printout S (s,b) = [(.23)2 + (.032)2 + 2(.083)2 + (.067)2 + 4(.17)2 + (.033)2 + (.017)2 + (.0083)2]
1/2
=
[.1892] 1/2
=
.43%
- 3. Wide Range Water Level Indicator S (s,b) = [(.067)2 + (.12)2 + 2(.083)2 + (.067)2 + 3(.17)2 + (.33)2 + (.25)2] 1/2 S (s,b) = [.2953] 1/2 S (s,b) =
.54%
- 4. Wide Range Water Level Accident Monitoring System Computer Printout S (s,b) = [(.067)2 + (.032)2 + 2(.083)2 + (.067)2 + 4(.17)2 + (.033)2 + (.017)2 + (.0083)2]
1/2 S (s,b) = [.1408] 1/2 S (s,b) =.38%
(4 a) Explanation of Hydrogen Monitor System (HMS) Block Diagram The block diagram represents one -HMS channel.
Recording capability for this channel is provided via the TSC AMS computer.
A second indentical independent channel also provides continuous indication in the main control room;
- however, the second channel does not include recording capability.
The hydrogen sensor is located inside containment, i.e.,
it is an in-situ device, and monitors the containment atmosphere directly without the use of sample probes, lines, or pumps.
COr~fA'Inrrf
-IQ corl 3oL. 01,0.
M~tin cor11WJL Moom
-~
I1OI2~L.
0110 LIr
____M~:
r0MpO A1eL m orI
- tic, PO~~~OVILf AcItWI AI &ArroilrZA0-VAI mULTI PLUCAce-fa Mpg: 5xo
- rlopir;,
rnOM:'31M ~u ~MP:
rMOxROv HAAD (MU6 Core A COP-10N (4-a)
OLOCJ< OIAGAM Hi-Mom6ler1 mor1I-roiln6 r:cy'3-rcr-I (t-Irr*c)
-10 (4b) Uncertainties in Containment Hydrogen Indication NUREG 0737, Item II.F.1, Attachment 6 Uncertanties are expressed as one standard deviation and as a percentage of full range.
Hydrogen Analyzer Accuracy (+ 4%)
+ 1.33%
Note:
Hydrogen Analyzer includes a temperature transmitter, pressure transmitter, hydrogen partial pressure transmitter and analyzer electronics.
The uncertainty stated envelopes the entire system during post accident conditions.
Indicator Random Bias 0.33%
(Accuracy + 1.0% of Span)
Indicator Ambient Temperature Effect 0.25%
(+ 0.03% per oC; 250C change)
Indicator Supply Voltage Effect 0.17%
(+ 0.05% per 1% of line change; 10% line change)
Indicator Uncertainty due to Reading by 0.17%
Operator (+ 25% of Smallest Division)
Isolator Random Bias (Accuracy + 0.5% of Span)
+ 0.17%
Isolator Supply Voltage Effect
+ 0.17% 1
(+ 0.5% for + 5% change in dc supply)
Isolator Ambient Temperature Effect
+ 0.17%
(+ 0.5% of span for 250 C change)
Universal Field Multiplexer (UFM)
+ 0.033%
Random Bias (Accuracy + 0.1%)
UFM Linearity (+ 0.05%)
+ 0.017%
UFM Repeatability (+ 0.025%)
+ 0.0083%
(4 c) Overall System Uncertainty Containment Hydrogen Indication
- 1. Indicator Uncertainty S (s,b) = [(1.33)2 + (.33)2 + (.25)2 + 2(.17)2] 1/2
= [1.998] 1/2
= 1.41%
w
-11
- 2. Accident Monitoring System Computer Printout S (s,b) = [(1.33)2 + 3(.17)2 + (.033)2 + (.017)2 + (.0083)2] 1/2
= [1.857] 1/2
= 1.36%
(4d)
Placement and Number of Hydrogen Monitors There are two hydrogen sensors located inside containment.
One is located near the top of the northeast exterior wall of Steam Generator E-1A Enclosure Building at elevation 64 feet.
A second hydrogen sensor is located near the top of the south wall of Steam Generator E-1C Enclosure Building at elevation 64 feet.
Our study for mixing of containment hydrogen after a large break LOCA at San Onofre 1, concluded that blowdown and the containment spray system provide for excellent mixing of the containment atmosphere.
Turbulent convective currents and strong air movement due to containment spray will achieve good mixing of air, steam and H2 by the end of core reflooding (t= 100 seconds).
Assuming a small break LOCA scenario, most of the hydrogen will collect in the high point pockets within the Reactor Coolant System (RCS).
The removal of the hydrogen is accomplished with the RCS vent system (See NUREG-0737, Item II.B.1).
(4 e) As explained in 4d above, the air, steam and H2 in the containment atmosphere are well mixed by the end of core reflooding after a large break LOCA.
Therefore, the containment hydrogen sensors would be exposed to a hydrogen concentration representative of that existing inside the containment atmosphere.
AHernandez:nphl