ML20080Q406
| ML20080Q406 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 10/05/1983 |
| From: | Kemper J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8310120392 | |
| Download: ML20080Q406 (25) | |
Text
.
, p.,
PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 1881 -1981 PHILADELPHI A. PA.19101 (215)841-4 5o 2 JOHN S. MEMPER
... = ::=.:_
00T 051983 Mr. A. Schwencer, Chief Licensing Branch No. 2 Divison of Licensing U. S. Nuclear Regulatory Commission Washington, D.C. 20555
Subject:
Limerick Generating Station, Units 1 and 2 Safety Evaluation Report Open Issue #8 Airborne Particulate Radioactivity Monitoring System
Reference:
Meeting Between PECO & NRC Auxiliary Systems Branch on September 22, 1983 File:
GOVT l-1 (NRC)
Dear Mr. Schwencer:
The referenced meeting was held to discuss the subject open item.
In the discussion, PECO described the Limerick Reactor Coolant Pressure Boundary Leak Detection System (RCPBLDS) in detail. Included in PECO's description were information on the system's method of operation and details on the system's compliance with Regulatory Guide 1.45 and ANSI /ISA Standard.S67.03.
At the conclusion of the meeting, it was agreed that the design of the RCPBLDS is acceptable. It was further agreed that PECO would document additional information presented at the meeting on operating experience with leak detection systems and provide FSAR changes associated with clarifications which had been discussed.
With regard to operating experiences, the drywell leak detection systems which comprise the RCBPLDS provided for Limerick were selected based on PECO operating experience with leak detection equipment at PECO's Peach Bottom Atomic Power Station (PBAPS), other industry operating experience and the work of ISA Subcommittee S67.03. Relevant PBAPS operating experience and practice is described in the following letters:
S. L. Daltroff (PECO) letter to J. F. Stolz (NRC) dated 12/15/82.
R. W. Starostecki (NRC) letter to S. L. Daltroff (PECO) dated 5/24/83, Combined Inspection Report 50-277/83-09 and 50-278/83-09.
800l 8310120392 831005
/!/
PDR ADOCK 05000352 f1 E
pyg
. w..., -
J. S. Kemper (PECO) letter to T. E. Murley (NRC) dated 9/15/83.
Our consultants have confirmed that our operating experience at PBAPS is typical of that of all other BWR's.
The equipment and systems provided at LGS for detection of RCPB leakage in the drywell (i.e. the RCPBLDS) meet or exceed the requirements and recommendations of ISA Standard S67.03 - 1982, Standard for Light Water Reactor Coolant Pressure Boundary Leakage Detection.
Attached are draf t revisions to FSAR Sections 1.8, 5.2 and 7.7 as well as a draft revised response to FSAR Question 410.23. The attached draf t FSAR revisions will be incorporated into the FSAR exactly as they appear on the attachments in the revision scheduled for November 1983.
Sincerely,
(?_
JTR/gra/I-2 Copy to: See Attached Service List
cc: Judge Lawrence Brenner (w/o enclosure)
Judge Peter A. Morris (w/o enclosure)
Judge Richard F. Cole (w/o enclosure)
Troy B. Conner, Jr., Esq.
(w/o enclosure)
-Ann P. Hodgdon, Esq.
(w/o enclosure)
Mr. Frank R. Romano (w/o enclosure)
Mr. Robert L. Anthony (w/o enclosure)
Mr. Marvin I. Lewis (w/o enclosure)
Judith A. Dorsey, Esq.
(w/o enclosure)
Charles W. Elliott, Esq.
(w/o enclosure)
Jacqueline I. Ruttenberg (w/o enclosure)
Thomas Y. Au, Esq.
(w/o enclosure)
Mr. Thomas Gerusky (w/o enclosure)
Director, Pennsylvania Emergency Management Agency (w/o enclosure)
Mr. Steven P. Hershey (w/o enclosure)-
Angus Love, Esq.
(w/o enclosure)
Mr. Joseph H. White, III (w/o enclosure)
David Wersan, Esq.
(w/o enclosure)
Robert J. Sugarman, Esq.
(w/o enclosure)
Martha W. Bush, Esq.
(w/o enclosure) i Spence W. Perry, Esq.
(w/o enclosure)
Jay M. Gutierrez, Esq.
(w/o enclosure)
Atomic Safety and Licensing Appeal Board (w/o enclosure)
Atomic Safety and Licensing Board Panel (w/o enclosure)
Docket and Service Section (w/o enclosure) 1
(
REGULATORY GUIDE 1,43 Control of Stainless Steel Weld Cladding of Low-Alloy Steel Components Rev 0, May 1973 This guide applies to welding of cladding to low alloy steels mode to coarse grain practice.
Limerick vessel plate and nozzle forgings are made to Line grain practice and a low heat input process is used.
Other components are not clad.
Therefore, the guide is not applicable.
(Category 1)
REGULATORY GUIDE 1.44 Control of the Use of Sensitized Stainless Steel Rev 0, May 1973 For GE scope of supply, this guide is not used as a design basis for Limerick and in some instances alternate approaches are used which, however, conform to the intent of this guide.
For the Bechtel scope of supply, there is conformance with the guide except for alternate approaches taken for non-sensitization and intergranular corrosion testing.
Details are discussed in Section 5.2.3.3.
REGULATORY GUI 4 { ~
Reactor Coolant Pressure Boundary
- g Leakage Detection Systems Rev 0, May 1973 l
The Limerick design complies with the intent of this Regulatory Guide.
Three diverse methods of detection have been provided.
The design bases, limitations, and operation of these systems are discussed in Sections 5.2.5.2.1.3 through. 5.2.5.2.1.5. -[Asg fru v()InJ neefor & 1$e. m d fm.g (Cotegory 1)
. of jtNSf/,I3/) SQu) $67.03, k
Rev. 17, 02/83 1.8-14
.5.2.4.7 System Leakace and Hydrostatic Pressure Tests The Class 1 leakage and hydrostatic pressure test p' System Leakage rogram meets the requirements of Section XI, Article IWB-5000, and Hydrostatic Pressure Tests." The technical specification requirements for operating limitations for heatup, cooldown, and system hydrostatic pressure testing will be met during such testing.
5.2.5 REACTOR COOLANT PRESSURE BOUNDARY LEAK DETECTION SYSTEM 5.2.5.1 Desion Bases The leak detection system is designed to Detect the occurrence of and alert operating personnel a.
to abnormal leakage from the reactor coolant pressure boundary (RCPB).
b.
Detect leakage from selected portions of systems located outside the primary containment, and not a part of the RCPB.
Remain functional following a safe shutdewn earthquake l
c.
(SSE), except as discussed in Sections 5.2.5.2.1.4 and 5.2.5.2.1.5 5.2.5.2 Description The RCPB leak detection system consists of temperature, pressure, flow, and radiation sensors, and associated instrumentation and clarms.
The system detects, annunciate's, and, in certain cases, isolates abnormal leakage in the following systems:
j a.
b.
Reactor water cleanup (RWCU) system i
Residual heat removal (RHR) system c.
d.
Reactor core isolation cooling (RCIC) system e.
Feedwater system f.
High pressure coolant injection (HPCI) system g.
Reactor recirculation ' system h.
Core spray (CS) system A summary of isolation and/or alarms of affected systems and the methods used appears in Table 5.2-7.
The table shows that those 5.2-31 Rev. 19, 04/83
.h4,
\\
i I
leak detection methods which detect gross leakage and initiate immediate automatic isolation.
Those methods which are capable of detecting small leaks initiate an alarm in the control room, at which time the operator can either manually isolate the leaking system or take other appropriate action.
5.2.5.2.1 Detection of Abnormal Leakage Within the Primary Containment Laaks within the primary containment are detected by continuously monitoring for a.
Abnormally high pressure and temperature within the primary containment l
b.
Rapid level increase in drywell equipment and floor drain sumps c.
A decrease in the reactor vessel water level d.
High gaseous radiation level in the primary containment atmosphere e.
High containment air cooler condensate flow.
In addition to these leak detection methods, selected RCPB components within the primary containment are provided with their own leak detection devices.
While some of the methods provided for detecting leakage within the primary containment are not redundant in themselves, it is not postulated that any one event could render all means of leak detection inoperable.
Each leak de e tion methods are discussed below. Tkg ( (76*f ded,of the iX LG5 mm :p
.wM. L a Q w,Q S.
.5.2.1.1 Drywell Tefnperature Monitor ng gpff/pg Drywell temperature monitoring provides an indirect method of Q
detecting RCPB leakage.
The drywell area unit coolers circulate and cool the drywell otmosphere to maintain the drywell at its design operating i
temperature.
Cooling water is supplied to the unit coolers by the Drywell Chiller Water System (FSAR Section 9.2.10).
A temperature rise in the drywell will indicate the presence of rocctor coolant or steam leakage and is detected by the drywell ter.perature monitors located at various elevations and at the inlet and outlet of the air coolers.
A discussion of indications j
cnd alarms for drywell temperature is given in Section 7.5.
O.
Rev. 17, 02/83 5.2-32
w.'
N LGS FSAR 5.2.5.2.1.2 Drywell Pressure Monitoring Drywell pressure monitoring provides an indirect method of detecting RCPB leakage.
The drywell normally ranges from slightly below to slightly above atmospheric pressure during reactor operation.
.The pressure typically fluctuates slightly as a result of barometric pressure changes and/or outleakage.
A pressure rise above the normally indicated value indicates leakage within'the drywell.
Drywell pressure monitoring is shown in Figures 5.1-4 and 9.4-5.
A discussion of indications, alarms, and protective functions for drywell pressure is (iven in Sections 7.2, 7.3, 7.4, and 7.5.
5.2.5.2.1.3 Drywell Sump Level Monitoring All leakage from RCPB components inside the drywell, with the exception of leakage from the main steam safety / relief valves (Section 5.2.5.2.1.8), flows directly to either the dr equipment drain sump or the drywell floor drain sump. ywell There are no other reservoirs in the drywell of sufficient capacity to prevent leakage from draining directly to either of these sumps.
Both drain sumps are identically-sized, horizontal cylindrical tanks located inside the reactor vessel pedestal below the diaphragm slab and vented to the drywell atmosphere.
The liquid radwaste collection system piping and instrumentation diagram is given in Figure 9.3-4.
These drain sumps are discussed below:
Drywell equipment drain sump - Certain RCPB components a.
within the drywell are, by the nature of their design, normally subject to a limited amount of leakage.
Thece components include pump seals, valve stem packings, and other equipment that cannot practicably be made to be completely leaktight.
These leakages are piped directly to the drywell equipment drain sump.
All of the various drains are open only to the equipment they serve, thereby receiving leakage only from identified sources.
Background leakage to this sump is determined during initial plant operation.
Rates of leakage collection in
(
excess of background indicates abnormal RCPB leakage.
b.
Drywell floor drain sump - Leakage from RCpa components
(
inside the primary containment which 'are not normally subject to leakage is collected by the drywell floor l
drain sump.
This leakage, which may originate from any number of sources within the drywell, is transported to the sump via the floor drain network within the drywell.
Thus, separation of unidentified leakage from the identifiable leakage routed to the equipment drain sump ensures that a small unidentified leakage that is of concern will not be mashed by a larger, acceptable, identified leakage.
5.2-33 Rev. 19, 04/83 l
d C
c.
Each sump tank has its own level transmitter which is monitored by a dedicated processing unit.
Normally closed drain valves are provided, enabling the level in l
each tank to increase as leakage drains into them.
The processing unit calculates an average leak rate for a given measurement period by establishing the amount of increase in level that occurred during the period, and converting that value into volumetric terms (gpm).
The processing units provide alarms in the main control room l
if the average increase in leakage for any given measurement period exceeds I gpm," - --^ '^"-
The alarm setpoint can be adjusted at the processing unit, l
which is located in the main control room, as the amount of acceptable identified leakage changes during operation.
Indication of the leakage rates is provided in the main control room on panel-mounted indicators and on CRT displays from the ERFDS system.
Level switches, which are independent of the level transmitters, open the sump tank drain valves when the level increases to'an upper setpoint value and keeps them open until the level decreases to an lower setpoint value.
The level switches then close the drain valves and reset the p:focessing units in order to start a new measurement period.
The measurement period must be long enough to ensure that the level transmitter loop can adequately detect the increase in level that would correspond to a 1 gpm increase in leakage and yet short enough to ensure that such a leak rate will be detected wit.hin an hour.
TM fuenhemur t'h wm W L n M,uvJ ovu. h ow.
The calibration interval for the level transmitters and processing units is every six months in accordance with the manufacturer's recommendation.
The transmitters which are located in the reactor enclosure and the processing units which are located in the main control room, are accessible during normal plant operation for calibration.
The transmitters can be isolated from the sump tanks by existing bypass manifolds.
Zero and span adjustments can be made using portable test equipment.
The processing unit functions can be calibrated by applying known input levels at the unit and observing the response.
The processing units and the level transmitters are qualified to withstand'an SSE.
'The system is energized by Class 1E power.
However, the system will be automatically isolated in the event of a LOCA.
Figure 9.3-4 shows the piping and instrument diagram for this system.
9 IEERT A
Rev. 20, 05/83 5.2-34
S lsA 62A T t
e-w e&ge g e
.se 6,eN=
m G W
8" AndJ ave A y'# -
e..._
- h A. m_2 m.
1 plt.a.
oAA m.g As M
. J
.42 M...-
JT...aMc w.kxA nn a.&.~%.
tenemm e me ese w a emme eh e.66e6 e
m e.o 4
- ge e sp.h m we M6 NM gaeme o pg-eep m emme ah eewe-N w. e e enga em 5
- -+==
.-e e -..e e.
_ m e-.-.am.
-e r.
essa -
v$4@6e w 6 644 Gemme em M
y, h
eg he e-h 8'*-6 66
++6 ON e6
g S
emme annemme.
mum. hee e mga he4 m
enamenknaen ea==m e=6 9 me em e 6
em
-mmeem.emeee-e amm>
- seom gN96
- Dum9th
-.=69a ps*
- h
- D 5 em Me
@=
SEmm6=
e 6 ag emee g ee
--wg me
.m G
sm=
M ggy,e, - - _
me e mim a h = Nh 6
e 9
m N
h*
We ed 9 m
4w 4
> Daw %ek en em e +e se mhe m enshe dum ses 4 M
5.2.5.2.1.4 Drywell Air Cooler Condensate Drain Flow Monitoring The drywell air cooler condensate drain flow monitoring system consists of six flow sensors and their associated flow transmitters that provide inputs to a separate flow monitoring device.
The flow sensors are mounted in the drywell air cooler drain lines located in the drywell.
There are a total of eight coolers.
Two flow sensors measure the flow from two air cooler drain line headers.
Four additional flow sensors measure the drain flow from each of the remaining coolers which are piped separately to the drywell floor drain sump tank.
The outputs from the six flow transmitters which receive their input from the flow sensors are added to provide a total continuous drain flow rate by the use of two summing units.
The continuous drain flow rate is monitored by a flow switch, located in the main control room, which will alarm if the rate exceeds 1 gpm over the preset identified leak rate.
The plant operator establishes the acceptable identified drain flow rate and adjusts the setpoint of this flow switch accordingly (i.e.,
if the identified flow rate is established at 5 gpm, the system will be set to alarm at 6 gpm).
The requirement to detect a 1 gpm increase in unidentified leakage within an hour is met by monitoring the continuous flow rate.
Indication of the total continuous drain flow rate is provided in the main control room on panel-mounted indicators and CRT displays from the ERFDS system.
The calibration interval for the flow transmitters and processing units is every six months in accordance with the manufacturer's recommendation.
The operability of the sensor can be verified remotely at the transmitter.
The transmitters and processing units, which are located in the reactor enclosure and the main control room, respectively, are accessible during normal plant operation for calibration.
The transmitters and the processing units can be calibrated by supplying known input levels and observing the response.
The proper operation of the flow sensors ehould be checked every six months by performing continuit'y and resistance tests for the RTDs and the 7 eater elements.
The flow I
sensors must be removed for cleaning, inspection, and calibration during each refueling outage.
l The drywell air cooler condensate drain flow monitoring system is l
qualified to withstand an OBE.
The system is energized by l
Class 1E power.
Figure'9.2-27 shows the piping and instrument l
diagram for this system.
l 5.2.5.2.1.5 Containment Airborne Radioactivity Monitoring The primary centainment is continuously monitored for airborne gaseous radioactivity.
A drywell air sample is extracted via sample line through containment penetration X-117B at El. 292 ft, l
area 16.
Air flow through the monitoring system is assured by 5.2-34a Rev. 23, 08/83 l
lu
=-
1 Tw/
the suction created by a vacuum pump.
The air sample is surveyed by the Geiger-Mueller tubes in the sampling chamber for its radioactivity content.
The air sample is returned to the drywell through the same containment penetration.
The level of radioactivity is recorded in the main control room in counts per minute.
The range is from 10 cpm to 10* cpm.
The corresponding concentration is 10-* to 10-8,Ci/cc.
Particulate and iodine monitors are not provided due to the substantial limitations of their usefulness as described below.
The noble gas monitoring equipment is shown in Figure 11.5-1.
It is not designed to be operable following an SSE.
Radioactivity level indication and alarms for loss of sample flow, high radiation, and downscale are provided locally and in the main control room.
Activity level indication in the control room is provided on a strip-chart recorder to provide
- 6. rend information.
The operability of the sensor and the electronic circuitry can be verified during operations from the auxiliary equipment roam.
A check source is supplied with the monitor.
Sample connections are also provided to facilitate additional sampling for laboratory analysis.
8 The radiation monitor is capable of being calibrated during power operation and will be calibrated in accordance with Technical Specifications requirements (Chapter 16).
The reliability, sensitivity, and response times of radiation monitors to detect 1 gpm in one hour of reactor coolant pressure boundary (RCPB) leakage will depend on many complex factors.
The major limiting factors are discussed below.
5.2.5.2.1.5.1 Source of Leakage Location of Leakage -- The amount of activity that would a.
become airborne following a 1 gpm leak from the RCPB will vary depending on the leak location and the coolant temperature and pressure.
For example, a feedwater pipe leax may have concentration factors of 100 to 1000 lower than a recirculation line leak.
A steam line leak may be a factor of 50 to 100 lower in iodine and particulate concentrations than the recirculation line leak, but the noble gas concentrations may be comparable.
An RWCU leak upstream of the demineralizers and heat exchangers may be a factor of 10 to 100 higher than downstream, except for noble cases.
Differing coolant temperatures and pressures will affect the flashing fraction and partition factor for lodines and particulates.
Thus, an airborne concentration cannot be directly correlated to j g, Rov. 23, 08/83 5.2-34b a
hD E
a quantity of leakage without knowing the source of the
- leakage, b.
-Coolant Concentrations -- Var.iations in coolant concentrations during operation can be as much as two orders of magnitude within a time frame of several hours.
These effects are mainly due to spiking during power transients or changes in the use of the RWCU system.
Examples of these transignts for 1-131 are given in Reference 5.2-6.
An increase in the coolant concentrations could give increased containment concentrations when no increase in unidentified leakage occurs.
c.
Other Sources of Leakage -- Because the unidentified leakage is not the sole source of activity in the containment, changes in other. sources will result in changes in the containment airborne concentrations.
For
. example, identified leakage is piped to the equipment drain tank in the drywell, but the tank is vented to the drywell atmosphere allowing the release of noble gases and some small quantities of iodines ased particulates from the drain tank.
5.2.5.2.1.5.2 Drywell Conditions Affecting Monitor Performance
'l Equilibrium Activity Levels -- During normal operation, a.
the activity release from acceptable quantities of identified and unidentified leakage will build up to significant amounts in the drywell air.
Due to these high equilibrium activity levels, the activity increase due to a small increase in leakage may be difficult to detect within a short period of time, b.
Purge and Pressure Release Effects -- Changes in the detected activity levels have occurred during containment venting operations.
These changes are of the same order of magnitude as approximately a 1 gpm leak and are sufficient to invalidate the results from iodine and particulate monitors, Plateo't, Mixing, Condensation, Fan Coolant Depletion --
c.
u Plateout effects on measured iodine and particulate levels will vary with the distance from the coolant release point to the detector.
Larger travel distances would result in more plateout.
In addition, the pathway of the leakage will influence the plateout effects.
For j
example, a leak from a pipe with insulation will have greater plateout than a leak from an uninsulated pipe.
Although the drywell air will be mixed by the fan coolers, it may be possible for a leak to develop in the vicinity of the radiation detector sample lines.
In 5.2-34c Rev. 17, 02/83
i' J
addition, condensation in the coolers and sample lines l
will remove iodines and particulates from the air.
Variations in flow, temperature, and number of coolers will affect the plateout fractions.
Plateout within the t
detector sample chamber will also add to the reduction of the iodine and particulate activity levels.
The i
uncertaintities in any estimate of plateout effects could be as much as one or two orders of magnitude.
j l
l 5.2.5.2.1.5.3 Physical Properties and Capabilities of the Detector a.
Detector Range -- The detector.was chosen to ensure that l
the operating range covered the concentrations expected in the drywell.
The operating range of the noble gas monitor is: 10-6 to 10-8,Ci/cc.
b.
Sensitivity -- In the absence of background radiation and equilibrium drywell activity levels, the detector has the following minimum sensitivity: 10-6,Ci/cc for Xe-133.
t c.
Counting Statistics and Monitor Uncertainties -- In theory, this radioactivity monitor is statistically able to detect increases in concentration as small as 2 or 3 times the square root of the count rate, i.e.,
at 1E+6 I
cpm an increase of 2E+3, or 0.2% is detectable; at 100 cpm an increase of 20, or 20% is detectable.
In addition, at high count rates the monitors have dead-time uncertainties and the potential for saturating the monitor or the electrc~.ics.
Uncertainties in calibration (plus or minus 5%), sample flow (plus or l
minus 10%), and other instrument design parameters tend to make the uncertainty in a count rate closer to 20 to l
40% of the equilibrium drywell activity.
d.
Monitor Setpoints -- Due to the uncertainity and extreme variability of the radioactivity concentrations to be measured in the containment, the use of tight alarm setpoints on the radioactivity monitor would not be practical or useful.
The setpoint, which would be required to alarm at 1 gpm, would be well within the bounds of uncertainty of the measurements.,
The use of such setpoints would result in many unnecessary alarms and the frequent resetting of setpoints.
The alarm setpoints for the radiation monitors are set t
significantly above normal readings to prevent nuisance l
alarms.-
1 O
Re,v. 17, 02/83 5.2-34d l
l l
'S-(klo c j
Operator Action -- There is no direct correlation or known relationship between the detector count rate and the leakage rate because the coolant activity levels, source of leakage, and background radiation levels (from leakage alone) are not known and cannot be cost-effectively determined in existing reactors.
There are also several other sources of containment airborne activity (e.g.,
safety relief valve leakage) that further complicate the correlation.
Thus, the procedure for the control room operator is to set an alarm setpoint at 1 gpm in one hour on the sump level monitor (measuring water collected in the sump that may not exactly correspond to water leaking from an unidentified source).
When the alarm is actuated, the operator will review all other monitors (e.g.,
noble gas, containment temperature.and prescure, air cooler condensate flow, etc) to determine if the leakage is from the primary coolant pressure boundary and not from an SRV or cooling water system, etc.
Appropriate actions will then be taken in accordance with Technical Specifications.
The review of other monitors will consist of comparisons of the increases and rates of increase in the values previously recorded.
Increases in all parameters except sump level will not be correlated to a RCPB leakage rate.
Instead, the increases will be compared to normal operating limits and limitations, and abnormal increases will be investigated.
Because the Technical Specification limit for leakage is allowed to be averaged over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, quick and accurate responses are not necessary unless the leakage is large and indicative of a pipe break.
In this case, the containment pressure and reactor vessel water level monitors will alarm within seconds, and the sump level monitor would alarm within minutes.or tens of minutes.
Radiation monitor alarms are not set to levels that are intended to corresp nd to the RCPB leakage levels because such correlations are not valid.
Because the l
contai'nment airborne activity levels vary by orders of magnitude during operation due to power transients, spiking, steam lea (s, and outgasing from sumps, an appropriate alarm setpoint is determined by the operator based on experience with the specific plant.
A setpoint level of 10 times the level during full power steady state operation may be useful for alarming large leaks and pipe breaks, but it would not always alarm for 1 gpm in one hour and therefore could not be considered as any more than a qualitative indication of the presence of abnormal leakage.
5.2-34e Rev. 17, 02/83
~
Due to the sum total of the uncertainties identified in the previous paragraphs, DML iodine and particulate monitors are not relied upon for immediate leak detection purposes, " --'"
~ ~ ' "
i..;t..T. = tzti ^ t The noble gas monitor is used to give supporting information to that supplied by the sump discharge monitoring, and it would be able to give En early warning of a major leak, especially if equilibrium containment activity levels are low.
However, the uncertainties and variations in noble gas leaks and concentrations would pre'clude the setting of a meaningful alarm setpoint. S b $
Igg M labv er 0itbW fdtI(EC4 a$C nc4$$
ID6EM pd SFS e tN;h ead T> Mck'e*, ley} d, &
e detected
,9 y, o%c
- ens.
Rev. 17, 02/83 5.2-34f
^
F 7
b.C LGS-FSAR L
7.7.1.9.7.8 AEDE-RMS Operational Considerations 7.7.1.9.7.8.1 General Annunciator outputs and control trip outputs are provided by this monitoring system.
Controls are both local and located in the auxiliary equipment room.
Gross radioactivity readings can be further diagnosed using grab samples.
7.7.1.9.7.8.2 AEOE-RMS Reactor Operator Information Inputs to the control room apprise the operator of concentrations of radioactivity an the air ejector effluents, including indications of fuel element deterioration.
Control trip capability is provided to prevent release of contamination to the environment.
Diagnostic capability is available.
7.7.1.9.8 Primary Containment Leak Detection Radiation Monitor (PCLD-RMS) 7.7.1.9.8.1 System Identification The objective of the PCLD-RMS is to indicate and record radiation levels of the primary containment atmosphere.
The instrument provides alarm capability in response to a rapid increase in this radiation level.
Alarm setpoints are d3caised k Sea %.
S. z.S. 2. I. T.3..
7.7.1.9.8.2 PCLD-RMS Classification The PCLD-RMS is a power generation system and is not related to cafety.
7.7.1.9.8.3 PCLD-RMS Reference Design Table 7.1-2 lists reference design information.
The PCLD-RMS 4+=
? oiwneu ww olo.e in 5.yvues ts :::11 g:r;;;; nr ata== leaks in th: pr it:r-, centei. ent 2nd does not have a safety function.
7.7.1.9.8.4 PCLD-RMS Power Sources Power is supplied by a 120 Vac instrument bus.
Safety-related power is not required for this application.
7.7.1.9.8.5 PCLD-RMS Equipment Design
/
7.7-75
1 F
pd l
LGS-FSAR l
(
(
7.7.1.9.8.5.1 PCLD-RMS General A gas sample is drawn from the primary containment and is passed through the PCLD-RMS to measure the concentration of noble cases.
'i Alpts capability is Outputs are transmitted to a control module in the.. pu cuxiliary equipment room, and to a recorder in the control room.
7.7.1.9.8.5.2 PCLD-RMS Circuit Descriptien The monitor channel has an upscale trip that indicates a rate of increase of radioactivity in the primary containment. equi"?!?nt l
6:
I;;kege seie of On.,.iion pas minui,. L s.. the naria++y exp--*=d id:ntifi:d I::ht;:.
to indicate instrument trouble.A downscale trip is also provided These trips annunciate, but l
provide no control action.
The trip.ci cuits are set so that loss of power causes an alarm.
Th'e five-decade range is selected to cover both normal and maximum radiation levels (short of an occident resulting in shutdown) in the primary containment.
If l
on accident occurs, the PCLD-RMS will be isolated, and its functions will cease.
I The PCLD-RMS monitoring rack is adjacent to the primary i
containment.
Outputs of this instrument are transmitted to the auxiliary equipment room and the control room.
Remote controls purge the noble gas chamber, reset'the alarm set points, and check the calibrations.
7.7.1.9.8.5.3 PCLD-RMS Testability Test signals are fed into the monitor via the control module in the auxiliary equipment room.
Check sources are provided for secondary calibration of each channel.
'7.7.1.9.8.6 PCLD-RMS Environmental Considerations l
p ee. sdsWo. %
l The monitoring rack is designed to meeb the environmental conditions adjacent to the primary containment.
Control modules and recorders are subjected to the environment of the auxiliary equipment room and' control room.
See Section 3.11 for the environmental conditions of the equipment locations.
1-7 '.0.0.7 ICLD-EMS Opes.L6vuol Considw& alivns 7 7.1.0.-S.'
canar=! Information Annwned:ter cutput: te PCLO-EMS eIera sign:10 ::: provided in the eentrol re:
Th; tu: !"darandent br:nch:2 Of th: cy: tem-provide emp2 rate criteria fnr lenk detecti:n.
Ti d f!!ter continwodsly accu.;eim..J.e.cti"e p:rticulete:-:nd iodin:: th.i cou we er !y::d in th; ce.ntin; reor for diagne; tic ps yvoe;.
u ^ w a v a r_
7.7-76 s
T r
- )
l LGS-TSAR L
4t i; n;; ;ap;;ted that + ha=a part i cul a t a/i ndi n= re p::s wilt be l
Opr;;;;t 54vv.
l 7.'.1.0.0.'.2 PCLD-?"S Rcerter Oper ter :nferastica
?npute ta th; svnts;: re:
provid; the s;;;t:r 0;:r;ter aith e c;cning; cf :nemelema ;Lang.=
o pc.m.cy containment radi5t.wo Irvwle.
Th.= infoEmoclon can ce word ss s Qwid; fOr et-^di:1 ::ti:n.
7.7.1.9.9 Hot Maintenance Shop Radiation Monitor (HMS-RMS) 7.7.1.9.9.1 Systek. Identification The objective of the HMS-RMS is to indicate and record the quantity of radioactive material.that eocapes from the hot maintenance shop ventilation exhaust duct.
Filters are provided in this duct,.and sample air is drawn from a station downstream of the filters.
Consequently, the quantity of radioactive material in the sample is normally negligible.
7.7.1.9.9.2 HMS-RMS Classification This system is a power generation system and is not related to safety.
7.7.1.9.9.3 HMS-RMS Reference Design Table 7.1-2 lists reference design information.
7.7.1.9.9.4 HMS-RMS Power Sources The power source of the HMS-RMS is the 120 Vac instrument bus.
7.7.1.9.9.5 HMS-RMS Equipment Design 7.7.1.9.9.5.1 HMS-RMS General The system consists of two channels:
one for monitoring particulate effluents, and the other for monitoring iodine effluents.
Radioactive material in the gas sample is accumulated on filters where it is sensed by scintillator-type detectors.
Output signals are transmitted to a microprocessor and then to a recorder.
Output signals from the control module are available for transmission to a centralized minicomputer for the purpose of insertion into Regulatory Guide 1.21 reports.
7.7.1.9.9.5.2 HMS-RMS Circuit Description Each channel has an upscale trip that indicates high radiation and a downscale trip that indicates instrument trouble.
These trips sound alarms, but cause no control action.
The trip 7.7-77
j}
LGS-FSAR L
The AEOE-RMS monitors have characteristics sufficient to provide accurate indication of radioactivity in the air ejector offgas.
The system provides the operator with sufficient information to control the activity release rate.
Sufficient redundancy is provided to allow maintenance on one channel without losing the system indications.
7.7.2.9.7.2 AEOE-RMS Conformance to Specific Regulatory Requirements No specific. regulatory guides or IEEE standards apply to this system.
7.7.2.9.7.2.1 AEOE-RMS Conformance to 10 CFR, Part 50, Appendix A, General Design Criteria (GDC) 7.7.2.9.7.2.1.1 Conformance to GDC 13, Instrumentation and Controls The system conforms to GDC 13 in that the instruments used cover the anticipated range of radiation under normal operating conditions with enough margin to include postulated accident conditions.
7.7.2.9.7.2.1.2 Conformance to GDC 60, Control of Release of Radioactive Materials to the Environment The system conforms to GDC 60 in that it controls the release of radioactive materials to the environment.
7.7.2.9.7.2.1.3 Conformance to GDC 64, Monitoring Radioactivity Releases The system conforms to GDC 64 in that it monitors radioactive releases resulting from normal operations including anticipated operational occurrences.
7.7.2.9.8 Primary Containment Leak Detection Radiation Monitoring System (PCLD-RMS) -- Instrumentation and Controls 7.7.2.9.8.1 PCLD-RMS Conformance to General Functional Requirements The PCLD-RMS supplements the leak detection instrumentation for the primary containment.
This monitoring system continually samples the containment (drywell) atmosphere for radioactive noble gases.
It is designed to respond to increases in the concentration of radioactivity in the containment atmosphere.
$ is ry.sY n Thc.j;t cr 15 ysolifi d for e scismic Cate; ry i securscncc, but 4t is not intended for use during or after a LOCA.
In this eventuality, the PCLD-RMS will be automatically isolated from the 7.7-131
0 LGS-FSAR i
(
J containment.
The PCLD-RMS is a power generation system, and is not safety related.
7.7.2.9.8.2 PCLD-RMS Conformance to Specific. Regulatory Requirements i
7.7.2.9.B.2.1 PCLD-RMS Conformance to Regulatory Guides l.45 7.7.2.9.8.2.1.1 Conformance to Regulatory Guidg 1973 Reactor Coolant Pressure Boundary Leakage Detection Systems yddc8y~ RCf8 e,
The PCLD-RMS is desigred to provide one of the thrVe independent means off
~
w -3e e tn detect a leak nf cee ;::: r p:; mingt M ;th.o cre
&ee r Thi: ::n r edily b; Ochiev:d chile th; cent inment
..imve her; i: rc :t.v 2y ;;;e; ef ;;fic;ctivity.
Ecw;v:. ehen r
- di;ect.ve
- terie! ;*edre!!y ercu u'et r in tha nc-tri sat Ftmos he re, th: percente; change required to detect ; ::;' vi e
ene ;;- fr ena hmr n
harn+=r nee;r-rei"ely ;mellir.
C nsequent;=/,
th: pr:bability of u.atow....in; this danvaa nf rencit.vaty will grade:22y da-!ine.
Th:r fere, thic nyetam eggt bg gred in Ke$eArnet!ce oe with atFer feet detectier ~e f;ffa^ gpYw pmy,$n i ' es to ma i 4 mk'bS' af S*f
'ST/
l& %- ir S.
l* O tai.ucy luid;
~
M meet:
e e n c engl k (6'e m m & nis t M.t
- f A W 7.7.2.9.B.2.2 PCLD-RMS 10 CFR50, Appendix A, General Design SG 7 03. fA Criteria (GDC) 7.7.2.9.8.2.2.1 Conformance to GDC 2, Design Bases for PrgectionAgainstNaturalPhenomena The PCLD-RMS is[ designed to continue its leak detection 8000 co ability af ter ahaf e shutdown earth uake (SSE)).11e e4(de#/#*$
de[atn syden a-ro jned 't. wiMh J an $SE(s4 e~oI l
ov-n c6E(q.0 eUlle,~ kQ, 7.7.2.9.B.2.2.2 Conformance to GDC 13, Instrumentation and Control The PCLD-RMS is designed to monitor for containment internal leakage over normal operation and anticipated occurrences, but not for accidents that result in containment isolation.
7.7.2.9.8.2.2.3 Conformance to GDC 64, Monitoring Radioactivity Releases 77,,gggg The PCLD-RMS provides a means of monitorin the containment atmosphere for radioactivity released from normal operations and anticipated operational occurrences.
(
7.7-132
I LGS-FSAR Lj 7.7.2.15.2 RI Conformance to Specific Regulatory Requirements
(
No specific regulatory requirements apply to refueling interlocks.
The refueling interlocks are designed to be normally onsrgized (fail-safe) and single-failure tolerant of equipment failures.
IEEE standards do not apply because the refueling interlocks are not required for any postulated design basis accident or for safe shutdown.
The interlocks are required only for the refueling mode of plant operation.
The requirements of 10 CFR, Part 50, Appendix B, are met in the manner set forth in Chapter 17.
No specific GDC requirements apply to this system.
7.7.2.16 Leak Detection System (LDS) -- Instrumentation and f'
Controls 7.7.2.16.1 LDS Confermance to General Functional Requirements
~
Following are the analyses to demonstrate how various general function requirements listed under the leak detection system (S2ction 7.7.1.16) are satisfied.
7.7.2.16.2 LDS Specific Regulatory Requirements
(
7.7.2.16.2.1 Conformance to Regulatory Guides 6.Y 7.7.2.16.2.1.1 LDS Conformance to Regulatory Guide f.
1973),
Reactor Coolant Pressure Boundary Leakage Detection. Systems Leakage into the primary reactor containment from identified cour uch as valve stem packing, recirculation pump seal, head
'et separated so that flow rates are monitored
-Cs cparatesly rom unidentified leakaoes and total flow rates can established >nd monitored eakage rom the main stfam line
[sefe F re11
~
r v
ve is an acen - ied eakage bec se pf the/
/ lo tion t
sens s
at e;ect his l but th /leakige ident'f eakag,o u r,c'e s.
i not mp tely p
te rom ified sparp to of t 's 3 ka is n required cau e an leak' f rom tf thef.ain steam in sa ty/re 'tjf varves
- fro a e ack 'r bre ifthe ine nd ces. itates
]>1 a shu own or r pa" ffhorefore, her is o ide ifi ed eaka e fr th sa ty/re lef V velyf 11 es du in plant rat n th nec ssi es secar ion
- fr4m u dent' le leaka A
y q g,yc,, Q ( g f-
)
4_
g, Similarily, the flow rate for unidentified leakage is monitored to detect a pipe break in the primary containment. 4;dietio.
men % crir.s of tha conteitemt eta,, sphere :!r retief!:::
R+g& torr C;id: Q :qu i
- g
,g 3 C,.Amdia~ % %i is mi0rN To
\\
y~.L.ra %.6 enen,,9 JAt RcPB led e.
3 y
% Ah frevW h dex.seJz. Sedu 5. 2 r.z.t. +.
fau) i
m L-a
_o
.g v;U poa 0., m d u. a % t is also
% st.d % [b n%
Yd
/
af ndL ne we
- a. r. w, p.>,w u a-a.s
,% SedL s.z. r. z. i. g.
t go 11e + /e<A de'%fw sj& ncl me,$ y'X lded u
Dt Ltmccit nef de ded J LbL 4 aed a easd k am sf Awsr/zss SY M sc1.a3 Q)?
\\
9 e
f J
%lh~m.-
.)
\\
LGS-rSxR
(
7.7.2.16.2.2 LDS Conformance to 10 CFR, Part 50, Appendix A, General Design Criteria (GDC) 7.7.2.16.2.2.1 Conformance to GDC 13, Instrumentation and Controls The leak detection sensors and associated electronics are designed to monitor reactor coolant leakage over all expected ranges required for the safety of the plant.
7.7.2.16.2.2.2 Conformance to GDC 19, Control Room Controls and instrumentation are provided in the control room.
7.7.2.16.2.2.3 Conformance to GDC 30, Quality of Reactor Coolant Pressure Boundary The system provides the means for detecting and locating the source of the reactor coolant leakage.
This also applies to the sump drywell, recirculating pump, and safety relief valve leak detection equipment.
7.7.2.16.2.2.4 Conformance to GDC 34, Residual Heat Removal Leak detection is provided for the RHR shutdown cooling lines penetrating the drywell.
7.7.2.16.2.2.5 Conformance to GDC 54, Piping Systems Penetrating Containment Leak detection is provided for the RHR shutdown cooling lines penetrating the containment.
Sump fill rate monitoring provides leak detection for other pipes penetrating the containment and reactor enclosures.
7.7.2.16.2.3 LDS Conformance to Industry Codes and Standards 7.7.2.16.2.3.1 Conformance to IEEE 344, (1971) Seismic Qualification of Class 1 Electrical Equipment l
l 1
The RHR and the drywell leak detection systems comply with this standard.
l 7.7.2.17 RodSequenceControlbystem (RSCS) -- Instrumentation and Controls 7.7.2.17.1 RSCS Conformance to General Functional Requirements The RSCS provides restraints on a rod drop accident assuming that the drop of the highest worth rod that can be developed at any time by one inadvertent error by the operator.
The quality level
~
~._
- v. zy. z. 3. z
\\
g yg Id her'tN rpMdffWN
\\
a
- -re J M M 2.
~ra enJ*e
,+
l.,
s LGS TSAR OUESTION 410.23 (Section 5.2.5)
(a) Provide drawings of the leakage detecting systems for-both the identified and unidentified collection systems.
drawings should indicate placement of instrumentation.The (b) Verify that each of the leakage detection systems has a Regulatory Guide 1.45, Position C.7. readout and alarm in'the co (c) Verify'that the airborne particulate monitoring system remains functional following an SSE.
j (d) Verify that the airborne radiation monitoring system is during operation. equipped with provisions to permit testing and calibration continuously.
Verify that the monitor operates-(e) Provide a discussion of the provisions to test and ae flow system.
As part of the discussion, s the frequency of testing and calibration. pecify and justify (f) Verify that the unidentified leakage detection system (drywell floor drainage system) is seismic Category I supported and specify the frequency of the periodic testing to ensure operability.
RESPONSE
(a) drawings of the leakage detection systems.Section 5.2.5.2.1 Figure 9.3-4 for drywell sump level mon'itoring and.
been changed.
(b) Each of the three systems provided for leak detection has with Regulatory Guide 1.45, readouts and alarms in the main control ro s
(c) Airborne particulate radioactivity monitoring equipment is j
not provided for the reasons described in Section.
5.2.5.2.1.5.1.
The drywell sump level monitoring system'is qualified to withstand an SSE.
The drywell air cooler condensate flow monitoring system is qualified to withstand an OBE.
seismic noble gas monitoring system is provided to supplement A non-the other two systems.
Therefor Guide 1.45 has been met M %A. e the intyd n~ of Regulatory % ).d 4
6 703 LM been ws% e. woo hd. gm e _
Q g Awspir4 5 (d) Testing and calibration of the airborne radiation monitoring system is discussed in Section 5.2.5.2.1.5.
410.23-1 Rev. 20, 05/83
LGS FSAR (e) Testing and calibration of the drywell sump level and air I
cooler condensate flow monitors is discussed'in Sections 5.2.5.2.1 3 and 5.2.5.2.1.4, roepactively.
7 (f) The drywell sump level monitoring sysfem is designed to withstand an SSE as described in Section 5.2.5.2.1.3. Periodic testing is also described in this section.
9 s
Rev. 17, 02/83 410.23-2 A