ML20065B086
| ML20065B086 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 02/17/1983 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE, YANKEE ATOMIC ELECTRIC CO. |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| SBN-469, NUDOCS 8302220388 | |
| Download: ML20065B086 (13) | |
Text
.
SEMON STATION IPUEBLIC SERVICE Engineedng Office:
Companyof New W 1671 Worcester Road Framingham, Massachusetts 01701 (617) - 872 - 8100 February 17, 1983 SBN-469 T.F.B 7.1.2 United States Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Mr. George W. Knighton, Chief Licensing Branch 3 Division of Licensing
Reference:
(a) Construction Permits CPPR-135 and CPPR-136, Docket Nos.
50-443 and 50-444
Subject:
Open Item Response (SRP 5.2.5; Auxiliary Systems Branch)
Dear Sir:
In response to the open item regarding detection of leakage from the reactor coolant pressure boundary, we have enclosed a revised version of the following FSAR pages:
1.8-17, 5.2-24, 5.2-25, 5.2-26, 5.2-27, 5.2-28, 5.2-29, 5.2-30, 5.2-31 The enclosed revised FSAR pages will be incorporated in OL Application Amendment 49.
Very truly yours YANKEE ATOMIC ELECTRIC COMPANY b
.w John DeVincentis Project Manager JDeV/smh cc: Atomic Safety and Licensing Board Service List l
goOI 8302220388 830217 PDR ADOCK 05000443 A
ASLB SERVICE LIST Philip Ahrens, Esquire Assistant Attorney General Department of the Attorney General Augusta, ME 04333 Representative Beverly Hollingworth Coastal Chamber of Commerce 209 Winnacunnet Road Hampton, NH 03842 William S. Jordan, III, Esquire Harmon & Weiss 1725 I Street, N.W.
Suite 506 Washington, DC 20006 E. Tupper Kinder, Esquire Assistant Attorney General Office of the Attorney General 208 State House Annex Concord, NH 03301 Robert A. Backus, Esquire 116 Lowell Street P.O. Box 516 Manchester, NH 03105 Edward J. McDermott, Esquire Sanders and McDermott Professional Association 408 Lafayette Road Hampton, NH 03842 Jo Ann Shotwell, Esquire Assistant Attorney General Environmental Protection Bureau Department of the Attorney General One Ashburton Place, 19th Floor Boston, MA 02108 i
Amendment 44 SB 1 & 2 February 1982 FSAR e'
Regulatory Guide 1.45 Reactor Coolant Pressure Boundary (Rev. O, S/73)
Leakage Detection System oi=
The design criterie for the reactor coolant pressure boundary leakage detection system :;rrly with Regulatory Guide 1.45.
The regulatory position taken in the guide has been considered and incorporated into the design of the leakage puds detection system.
Lomptta e wit EEE-27 71 i limit to p vidin the apabirtty fo test'ng and c beati of th leak etect' n ins ument only Lea detect'on i stru-men, sitch s tem ratur, flows and h idity have apab* icy fo per* dic t sting d ing r uelin outage The irborn rad
- activ'ty det ctor as ility or pe odic t ting uring wer perat n.
f
/the cap Re rding ection
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DE The r ponse t' e of c tai nt air rne artic ate r ios ivity onit ring
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f devi es to d ect a eg leakag rate y va from he iven r uir nt de nding equili riu conditio s in ontai ent a th incepti n of the
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For additional discussion on this subject, see Subsection 5.2.5.
4 Regulatory Guide 1.46 Protection Against Pipe Whip Inside (Rev. O, 5/73)
Containment The design.against pipe whip is in full compliance with Regulatory Guide 1.46, as discussed in Section 3.6.
- j Regulatory Guide 1.47 Bypassed and Inoperable-Status Indication (Rev. O, 5/73)
'for Nuclear Power Plant Safety Systems Provisions have been made in the design of the plant safety _ systems to meet the intent of Regulatory Guide 1.47.
Automatic indication, at the system level, of bypassed and inoperable status i
Once of the protection systems has been provided in the control room.
activated, the systec-level indicator will remain on until the activating condition is cleared.
Each system-level indicator is also capable of being manually activated in the control room.
Additional discussion on this subject is presented in Section 7.1 Regulatory Guide 1.48 Design Limits and Loading Combinations for Seismic Category I Fluid System Components (Rev. O, 5/73)
NSSS components are designed using the stress limits and loading combinations presented in Sections 3.9(N).1 and 5.2 for Code class I components and in k
I 1.8-17 9
b.
Pressurizer Relief Tank (PRT)
The PRT condenses and cools the discharge' from the pressurize'r '
safety and relief valves. Discharge t' rom the smaller relief. valves located inside the containment is also piped to the PRT.
~~ - -
ShideiEifieif T.eikage to containment - -
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The majority of leakage from sources within the reactor containment is ulti-mately collected in the containment drainage sumps. Drainage trenches on the floor of the containment channel leakages and condensation to the sump.
The leakage rates can be established and monitored during plant operation.
Unidentified leakage to the containment atmosphere is kept to a minimum to permit the leakage detection systems to detect positively and rapidly a small increase in the leakage.
Identified and unidentified leakages are-separated so that a small unidentified leakage will not be masked by a comparatively larger identified leakage.
DW 5.2.5.3 Leakage Detection Methods ijyfte[o1Jwigga ntg*[*id d
t r g g msg e
B en ge te to s
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od so ha on nu s nit ri of om i nMfi(d dd u t ea ge s ma e p ssi e d Figure 5.2-2 identifies the various monttoring instruments employed for this purpose.
a.
Design Bases -
The following design bases were established to satisfy the require-ments of General Design Criterion 30 for design diversity and redun-dancy for the RCPB leak detection systems.
Leakage to the atmosphere from systems containing radioactive 1.
fluid, which would result in an increase in overall containment radioactivity levels, are detected by the use of airborne radioactivity monitors.
~~
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2.
Indications of an increase in local humidity and temperature from any source releasing hot liquid to the atmosphere is provided by the humidity and air temperature monitors.
3.
Temperature monitors are provided to indicate temperature flux vs. flow of leakage in drainage and relief lines and
- tanks, e.g., reactor vessel flange, pump seal and primary valve leakof fs which discharge to the RCDT and the PRT.
4.
Liquid level monitors are provided for drainage sumps and tanks to monitor the leakage.
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The RCPB leakage detection is implemented by using continuous monitoring methods and/or a periodic RCS water inventory balance method. These methods provide a means f5r detection of both identified and unidentified leakage.
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5.
The systems are designed to reliably annunciate increasing leakages.
The. radiation monitors are provided with failure
-alarms that will indicate any instrument troubles.
6.-- The monitors provided shall_sppply. sufficient information to enable deduction of leakage rates, differentiaElon, identifi-
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cation and general location of leaks.
b.
Monitoring System s+bAured/AK-The reactor coolant leakage'Je*retice systems consist of the following cet:;scles of :
- c:; and detector.
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Containment Drainage Sump Liquid Inventory Monitor As indicated in Subsection 5.2.5.2g leakage-is collected in containment drainage sumps. Sump level monitoring is provided to-inventory the drainage handled. Level switches are used to maintain the' sump level between pre-determined levels, by cycling the sump pump. Leaks are indicated by the computer log and trend of the sump level and pump operation.
Continuous sump level monitoring is available in the main control room.
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2.
Containment Airborne Radioactivity Monitor l
This channel monitors a sample drawn from the containment atmosphere for particulate and gaseous radioactivity.
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monitoring is done in batch mode by analyzing the charcoal cartridge periodically in the laboratory. A sample which is representative of the containment atmosphere is drawn by an integral pumping system, from containment to a moving paper particulate filter, an iodine cartridge and a noble gas chamber. The air sample is then discharged back to the containment. One radiation detector is used to monitor the particulate filter.and the second radiation detector monitors the noble g'As. The detectors are of Beta 'Scintillatohtype.
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CZ The detector outputs are converted into microcuries per cubic centimeter by the microprocessor. During maintenance, portable monitors will be utilized.
3.
Containment Humidity Monitors The humidity detector system of fers another means of i
detecting leakage into the containment. Six humidity sensors are located in various areas of the containment structure.
As there is no leakage of moisture from the outside, any increase of humidity is a== = ="ra of Icakage inside the containment.
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5.2-25
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4.
Reactor Vessel Flange Leakoff The reactor flange and head are sec. led by two metallic 0-rings. Leakoff connections are provided between the
.0-rings and beyond the outer _0-ring.
The leakage is piped to ~
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the RCDT. A high temperature measurement by an RTD mounted in the piping indicates the reactor coolant lea age.
5.
Reactor Coolant Drain Tank The various sources of leakage to the RCDT are identified in Subsection 5.2.5.1.a.
The RCDT is provided with temperature, pressure and level indications by which leakage is determined.
6.
Reactor Coolant Pump Seal Leakoff Refer to Subsection 5.4.1.3 for a complete discussion of the reactor coolant pump shaft seal leakage. Seal water enters the pumps through a connection on the thermal barrier flange, and is directed to a plenum between the thermal barrier housing and the shaft. Here the flow splits: a portion flows down the shaft to cool the bearing and enters the RCS; the remainder flows up the shaft through the No. I seal, a controlled leakage seal. After passing through the seal, most of the flow leaves the pump via the No. I seal leakoff
~
line. Minor flow passes through the No. 2 seal and leakoff
- i line. This flow is monitored by a flow switch. A back flush injection from a head tank flows into the No. 3 seal between its " double dam" seal area. At this point, the flow divides -
with half flushing through one side of the seal and out the No. 2 seal leakoff while the remaining half flushes through l.
the other side and out the No. 3 seal leakoff which uses a l
standpipe. Excessive leakage backs up in the standpipe until it overflows out the top, with the overflow directed to con-j tainment sump A.
A high level of the upper standpipe is alarmed, indicating excess leakage. _
7.
Pressurizer Relief Tank (PRT)
The leakages directed to PRT are identified in Subsection 5.2.5.1.b.
During normal operation, the leakage to the PRT is expected to be negligible, since all the valves are designed to minimize leakage at the normal system operating pressure. Temperature detectors are provided in the discharge piping of each valve to indicate possibit leakage.
I PRT level, temperature and pressure indications and alarms l
are provided to indicate the Icakage.
s 5.2-26 L
Containment Ambient Temperature Monitors Platinum resistance temperature detectors are strategically located throughout the containment to detect local temperature changes and will assist in laa.lizine a leak.
C.
RCS Water Inventory Balance The periodic RCS water inventory balance is designed to be conducted during steady state conditions with minimal T-AVG variance.
In the course of this inventory the following parameters are monitored:
1.
Time 2.
T-Avg 3.
Pressurizer Level 4.
VCT Level 5.
PRT Level I
6.
RCDT Level 7.
BAB Flow Totalizer Changes in inventory due to sampling, draining, and steam generator tube leakage are accounted for separately. During the conduct of this inventory every effort is made to avoid additions to the RCS, pump down of the RCDT, or diversion from letdown to the VCT.
Changes in the parameters are calculated over a convenient time period (the longer the period the more accurate the results). The inventory change rate is determined by summing the volume change associated with each parameter and dividing this value by the time interval. The difference between the containment sump leakage rate and the inventory change rate will indicate leakage from sources other than the primary system.
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5.2.5.4 Intersystem Leakage Detection The following three types of detection methods are employed to monitor systems connected with the RCPB for signs of intersystem leakage:
Primary Component Cooling Water System Radiation Monitors a.
These are gamma sensitive scintillation detectors. Liquid sample is drawn from the discharge side of the primary component cooling water pumps and returned back to the suction side. This system monitors primary component cooling water for radioactivity indica-tive of a leak from the reactor coolant system or from one of the radioactive systems which exchanges heat with the primary component cooling system. These detectors are provided with the flow information, so as to get the radioactivity in terms relevant of microcuries per cubic centimeter.
b.
Condenser Air Evacuation Monitors MVh This method is employed for detection of steam generator tube leaks. Noble gases present in the steam generator tube or tube sheet coolant leakage leave solution in the steam generator and This are ultimately vented along with other non-condensables.
detector is a gross beta scintillator. The detector is directly mounted in the discharge line of the three air evacuation pumps.
Steam Generator Blowdown Sample Monitors c.
These monitors provide indications of primary to secondary leaks in the steam generators by analyzing the liquid phases of the four
~~ ~~
steam generator secondary sides. - These-are-of - the -gamma-sensitive'- -
scintillation type. Pressures and temperatures are reduced for i
detection purposes.
5.2.5.5 Sensitivity and Response Time of Detectors (24ttWs0 70 LO Mf// W/TY 5 The sensitivity and response time of each leakage detection methogesployed 6 -nnitariag the lenkage te th: cent s in;;:nt it dicen:::d belv.,
The.
= thada enoable of detecting n lanbg= *ete (cc it; equi::1:nt) te ;hm ov..tein A*c-t=A r i _ :
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5.2-27
SB 1 & 2 rVe &ce3 so-9 udro w.b b
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FSAR sys b hos et 5ensivW3y of gn and on oewacy o( t6%
j $
11 Containment Drainage Sump Inventory Monitoring J
a.
3U y(
Normal leakage from all the unidentified sources within the containment is estimated to be in the range of 20 to 40 gallons
{*,S per day.
RCPB leaks on the order of 1 gpm are very large in comparison hnd are easily detected by log and trend of containment 2
4 sump level. Additionally, the level transmitters have sufficient Uj0 resolutions to detect change in level due to a flow of as little ti as 1 gpm.
Leakages of the order of 0.05 gpm are detected in a few
)$$
I.;
hours with the expected background leakage. % (eakage of 1 gpm can be detected in-eppr =*=:tely (12ter) minutes.
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b.
Containment Air Particulate Monitor f
The containment air particulate monitor is one of the most sensitive
. hjO instruments available for detection of reactor coolant leakage into the containment.% The g asuring range is 10-10 to 10-6 p Ci/cm3 I
The saae-tt-wity-is '~Eh'e N;m$i where the base line leakage is The base line airborne activity is kept low by adjusting the
' low.
valve packings and pump seals properly. The air particulate monitor b[4 is capable of detecting leakage of I gpm.in-(12tgr) minutes, if
~less u " 50 the reactor is operating with 0.12% fuel defects (reference Subsection 11.1.7.1) and a coolant corrosion product level of 2.3 x 10-2 p Ci/gm (reference Table 11.1-1), assuming % base line leakage activh However, during the initial period of operation, and following refueling when the coolant activity is dr % TW low, response time will be longer than those of other types of monitors which do not rely on coolant activity for detection.
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Containment Radioactive Gas Monitor s
Caseous activity in the containment atmosphere results from
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fission gases (various Kr and Xe isotopes) in coolant leakage and 1
- k (/cc from Ar-41 produced by activation of air around the reactor I
+ cecirt
- hc_ mmlLI.li, e5 The gas monitor 49 ands nn ob /0., c vessel.
The range of the monitor is 10-6 to 10-2 The gas monitor l's71sli"t'o'detedt a Leakage of-l gpm-in--- and,
.act'v'ty level.
j 3
b F Ci/cm.(letud minutes if the reactor is operated with 0.12% fuel defects of d4@%
TCuracif M
(reference Subsection 11.1.7.1).
'This prc ef dc useful-baekup-co athcr "C"3 icahag: ac tac t==.
ontdinmeit Humidity / Monitors J
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ity,,of the/umi' ity
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ari s wi contjfnmen h
ety tors
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no'n-radi'oac ti6e 'd'is chb e. The umi 'ty j tectp has sensit'ivity'(of/0. loF dew p n
m rature.
e res onse tme
/ app'rbximatel'y( (lat r) min t [ fo a (1 ter) pm le age.
The
-helek f
of caka to th cont inme t.
system is an i'ndir ct-jddi atio If the/ um'idity onitgrUd,tects an 'ncreheincntainment h
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5.2-28 i
l
t SB 1 & 2 Amendmene. 46 FSAR August 1982 moisture without a corresponding increase in activity level, y e indicated source of leakage would be judg'ed to be a non-
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radioactive system.
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e._
Cohainment Temperature Monitors The t perature sensors have an accuracy of + (lat r) 0F.
Their sensiti icy and response time is dependent on the distance of the sensor f m the leak and the amount of mixing o the containment atmosphere The temperature sensors are an a in determining the location of leak from a high temperature s stem.
f.
Primary Compone t Cooling LTiiuid Radiatio. Monitor 3
The detector range is 10-7 to 10-3 C'
m.
The monitor response time is dependent up n the leakage ra e and the amount of fission product and corrosion roduct activ' y in the primary coolant.
With 0.12% failed fuel reference bsection 11.1.7.1), and a coolant activity of 3.8 100 C /gm excluding H-3 and N-16, (reference Table 11.1-1) a leak e rate of 1 gpm is detected in 60 minutes. Sequential iso t'on of various components af ter l
detection of leakage can be ed to identify the point of leakage o
within a relatively short t' e.
Even in the absence of failed h,
fuel, the monitors provide an ef etive means of detection and identification of the so ce of 1 pm leak.
g.
Condenser Air Evacuat* n Gas Monitor 1 to 106 e unts/ minute (which is The range of the mo itor is 10 ge of 10-6 to 10-2 Ct em3, assuming 0.5%
equivalent to a r failed fuel).
S nsitivity varies with the actor coolant l
activity. Thu for a coolant activity of 3.
x 100 gCi/gm l
excluding H-3 and N-16 (reference Table 11.1-1 and 0.12% clad I
defects (re rence Subsection 11.1.7.1), a leaka e of 1 gpm can be detected i 60 minutes.
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l h.
Steam G erator Blowdown Monitors I
eam generator blowdown monitors have a range of 1 -6 to 10-2 l
TheC'/cm. Design basis steam generator tube leakage is e pected 3
t be approximately 12 gpd.
The monitor response time is ependent upon mixing time in the steam generator secondary ide water volume, steam generator blowdown rate, abnormal leakage rate and the amount of fission product and corrosion product activi in the primary coolant. Thus, for 0.12% failed fuel (reference Subsection 11.1.7.1) and a coolant activity of 3.8 x 100 Ci/gm excluding H-3 and N-16 (reference Table 11.1-1) and assuming no base line leakage activity, this monitoring system will respond to a sudden occurrence of a 20 gpm primary-to-secondary leak in about
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20 minutes.
5.2-29 l
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SB 1 & 2 i
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Re ctor Coolant'De n Tdk
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-The reactor coolant pump eal (No.j/2) leakage of /.gp acc nts for the'majo'rity of no alJeaka t the f(CDT. Valvd stem
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,' leakage contribute's a ra tion f a' gall n per our /whil'e the e9 age. The 1 ka e lea ing C6 the d
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ot)dr son'rces h ve n li tble
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sofdCDT 3CDT fr$m the V
CPB s d tec d tre emp atur,
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presso're and evej
-p 5.2.5.6 Seismic Capability ord confcJ t d g 3,% levd Nh A
The_ containment airborne radioactivity monitor is classified seismic Catgory I, i
_and_ satisfies the requirement of NRC Regulatory Guide 1.45, for seismic quali-fication.
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5.2.5.7 Indicators and Alarms Positive indication of RCPB leakage is provided in the main control room by the instruments located there, in association with the RCPB leakage detection subsystems. All indicators, recorders, annunciators and computer logs are readily available to the main control room operators. The operators are provided with the procedures for interpreting tihe indic~ations to identify
~~
the leakage source, and with criteria for plant. operation under leakage.
conditions.
l Continuous sump level monitor is available to the plant computer. The computer monitors the sump level as well as the running of the sump pump in l
order to determine the leakage. Sump level high and low level alarms are also available.
1 For the humidity monitors, absolute humidity indications at various locations i
in the containment with high alarm points are provided at the main control j-room via the Main Plant Computer System (MPCS).
For PRT and RCDT, temperature and level detectors are provided so that high and low level indications and high temperatures are alarmed. Temperature detectors are provided in the discharge piping of each safety and relief j.
valve, reactor vessel flange, leakoff piping pressurizer vent, and reactor j
vessel head vent, to indicate possible leakage. Temperature detectors at various areas of containment monitor any high ambient temperature, aiding in locating the leakage source. A high temperature of reactor vessel flange leak at the main control room will indicate inner and outer seal leaks.
High flow indication in Seal No. 2 leakoff and high level indication in stand pipe connected to Seal No. 3 will alert the control room operator to I
reactor coolant pump seal leaks.
I For all radiation monitoring systems, local indication of activity and high level alarm are provided locally at the monitor. By means of the RDMS, indication and alarms are provided at the main control room. Equipment i
failure alarms are also available.
i 5.2-30
_. _ _ _ _.... ~.,.. _.,, _. _... _ _ _ _,..._ _..._.___ _.. _ _ _. _
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SB 1 & 2 Amendment 44 FSAR February 1982 5.2.5.8 Testing Calibration and functional testing of the leak detection systems, i.e., M
_r,eL.
c.: WM ty detecti=, sump level detection, containment air and partic-ulate monitoring,--ete. will be performed prior to initial plant start-up.
During normal plant operation, periodic readings of leakage detection system - -
instrumentation will indicate Icakage trends. Periodic inspection and calibra-tien of leak detection instruments will ensure accuracy and dependability.
&& BE MfMMP hfp& d'M UMAiW AM For all radiation monitors, a primary calibration is performed on a one-time basis, utilizing typical isotopes of interest to determine proper detector Secondary standard calibrations are performed with multiple radi-response.
ation sources to confirm the channel sensitivity obtained on primary calibra-tion. This single point calibration confirms the channel sensitivity. Each monitor has a diagnostic program built into its microprocessor. This program continuously conducts a diagnostic routine within the monitor and provides an alarm input to the RDMS when a failure is detected. Each monitor is equipped with a " check source" that is inserted upon the consnand of the RDMS.
Each time the check source is inserted, the microprocessor measures and stores the effect of the check source and compares it to the previous reading to obtain an indication of calibration trends. A circuit calibration test is accomplished by inputting a precalibrated pulse signal to the channel.
Proper indication at the meter will verify the calibration of the circuitry.
c.f,if 5.2.5.9 Technical Specification The technical specification is provided in Chapter 16, Section 3/4.4.7.
5.2.6 Reactor Coolant Vent System 5.2.6.1 Design Basis i
L l
l The reactor coolant vent system is designed to allow venting the large quan-l tities of non -condensible gases that can be generated within the reactor following core damage.
It provides,a vent path to the containment atmosphere
- - - via the pressurizer relief tank to insure that non-condensible gases cannot accumulate in the core to the point where core cooling would be interrupted and further core damage occur.
5.2.6.2
System Description
This system (see Figure 5.1-1, Sheets I and 6*) provides the capability to l
vent the reactor coolant system from two locations:
the reactor vessel head and the pressurizer steam space. The vent valves will be manually operated from the control room. The function of these vents is to vent any non-condensible gases that may collect in the reactor vessel head and in the pressurizer following core damage.
(
- Undergoing revision 44 l
5.2-31 i
_ _ _ _ _ _