ML20002C408
| ML20002C408 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 05/10/1976 |
| From: | Bilby C CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| Shared Package | |
| ML20002C404 | List: |
| References | |
| NUDOCS 8101100264 | |
| Download: ML20002C408 (17) | |
Text
--
c.
.~
),,
' N Limiting Conditions for Operation Surveillance Requirewent D
11.3.1.4 EMERGENCY CORE COOLINC SYSTEM l
ll.h.l.h EMERGENCY CORE C' 0 LING SYSTEM l
Applicability:
Applicability:
D Applies to the operating status of the emer-Applies to periodic testing requirements for gency core cooling system.
the emergency core cooling systems.
Objective:
Objective:
A To assure the capability of the emergency To verify operability of the emergency core core cooling system to cool reactor fuel in cooling systems.
r' "
the event of a Loss of Coolant Accident.
Specification:
Specification:
A.
Each month the following shall be performed:
A.
The two core spray systems (original and Verify the operability of MO-7051, redundant) shall be operable whenever
-7061, -7066, -7073 and -707h by remote l
the plant is in a power operation con-manual actuation.
dition except as specified in Specifi-
_l w
cation B below. The original core spray Leak testing of the core spray heat system shall also be operable during exchanger, refueling operations.
Automatic actuation of both fire pumps.
l B.
If the redundant core spray system be-B.
At each shutdown the following shall be comes inoperable and the valves in the 7
other core spray system are aemonstrated to be operable by manual actuation in Verify the operability of MO-7070 and 1
accordance with 11.h.1.h.E, the reactor
-7071 by remote manual actuation.
l
' ~
may remain in operation for a period not to exceed seven (7) days.
C.
At least once every six (6) months of peration other than shutdown the fol-l C.
The core spray recirculation system ng shan M perfomed:
shall be operable whenever the plant is in a power operation condition Automatic actuatian of the core spray except as specified in D below.
sysh Mm vM Me fhv mmW blocked (M0-7051, -7061, -7070 and t
-7071).
t 4
~.
3 Limiting Conditions for Operation Surveillance Requirement 11.3.1.h EMERGENCY CORE COOLING SYSTEM (Contd) l 11.4.1.h EMERGENCY CORE COOLING SYSTEM (Contd) l D.
One core spray recirculation pump may D.
At each major refueling outage, the fol-be inoperable for a period not to exceed loving shall be performed:
seven (7) days when the reactor is in operation.
Calibration of core spray system actua-tion and flow instrumentation.
E.
The core spray recirculation heat ex-changer shall not be taken.out of ser-Flow testing of the two core spray system vice during power operation for periods containment isolation check valves.
exceeding four (4) hours. The heat exchanger shall be considered inoperable Operability of the check valves between and out of service if tube bundle leah.
M0-7051 and M0-7061 and :40-7070 and MO-7071.
age exceeds 1.h gpm.
Calibration of fire system basket strainer F.
Both fire pumps (electric and diesel) differential pressure switches.
and the piping system to the core spray system tie-ins shall be operable when.
Operability of the core spray recirculation ever the plant is in s power operation system.
condition and refueling except as specified in Specification G below.
E.
When a system becomes inoperable, its l
redundant system shall be demenstrated G.
If a fire pump becomes inoperable and to be operable within four (h) hours and the other fire pump is operable, the every 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> thereafter. It is not reactor may remain in operation for a necessary to demonstrate the operability period not to exceed seven (7) days.
of initiation sensors or circuitry for
~'
core spray valves.
H.
If Specifications A, B, C, D, E, F and l
G are not met, a normal orderly shutdown F.
Instruments shall be checked, tested and shall be initiated within one (1) hour calibrated at least as frequently as and the reactor shall be shut down as listed in Table 11.h l.h(a).
described in Section 1.2.5(a) within twelve (12) hours and shut down as described in Section 1.2 5(a) and (b) within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. No work shall be performed on the reactor on its connected systems which could result in lowering the reactor water level below elevation 607'9".
a Limiting Conditions for Operation Survei,11ance Requirement 11.3.1.h EMERGENCY CORE COOLING SYSTEM (Contd) l I.
Until such time as the effectiveness of redundant core spray nozzle has been
+
proven,'the fire water makeup system to
".he condenser hot well shall be operable and ready for service during power oper-1 ation. If the fire water makeup system becomes inoperable and not corrected, a l normal orderly shutdown shall be initi-p-
ated within one (1) hour and the reactor shall be shut down as described in Sec-tion 1.2.5(a) within twelve (12) hours and shut down as described in Section 1.2.5(a) and (b) within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
J.
Instrument set points shall be as speci-fled in Table 11.3.1.h(a).
sn Bases:
The core spray system consists of two automatically actuated independent double capacity piping headera capable of cooling reactor fuel for a range of Loss of Coolant Accidents. Either system by itself is capable oi' pro-
^
viding adequate cooling for postulated large breaks in all locations. When adequate depressurization 1ates are achieved in the postulated small-break situation, either core spray system provides adequate cooling. For the largest possible pipe break, a flow rate of approximately 400 gpm is required after about 20 seconds.
Each core spray system has 100% cooling capacity from each spray header and each pump set. Thus, specifying both systems to be fully operational will assure to a high degree core cooling if the core spray system is required.
In addition, the original core spray is required to be operable during refueling orerations to'9rovide fuel cooling in the unlikely event of an inadvertent draining of the reactor vessel.
The coro spray systems receive their water supply from the plant fire system. The plant fire system supply is from Lake Michigan via two redundant 1,000 gpm fire pumps, one electric and one diesel driven.
These pumps start automatically on decaying fire system pressure.
The core spray recirculation system is provided to prevent excessive water buildup in the containment sphere and-to provide for long-term, post-accident cooling.
The system consists of two pumps- (h00.gpm each) and a heat ex-changer. The pumps take a suction from the lower levels of containment and disciarge to the core spray headers.
The system is actuated manually when the water level in the containment rises to elevation 587 feet. The.587-foot elevation will be achieved between 6 to 2h hours operation of one core spray and one containment spray system.
~
Bases:
(Contd)
A. test tank and app' rL te valving is provided in the core spray recirculation system so the pump suction conditions and the ni characteristics of the system can be periodically tested.
One core spray recirculation pump has adequate capacity to provide fuel cooling at anytime following a Loss of Coolant. Accident. Continuous containment spray operation is not required during the post-accident recirculation 5
phase if only one recirculation pump is available.
The operable status of the various systems and components in to be demonstrated by periodic tests. Some of these tests will be performed while the reactor is operating in the power range. If a component is found to be inoper-r*
able, it will be possible in most caces to effect repairs and restore the system to full operability within a relatively short time. For a single component to be inoperable does not negate the ability of the system to per-form its function, but it reduces the redundancy provided in the reactor design and thereby limits the ability to tolerate additional equipment failures. To provide maximum assurance that the redundant component (s) will operate if required to do so, the redundant component (s) is to be tested prior to initiating repair of the inoperable component.
If it develops that (a) the inoperable component is not repaired within the specified allowable time period; or (b) a second component in the same or related system is found to be inoperable, the reactor will initially be removed from service which will provide for a reduction of the decay heat from the fuel and conse-quential reduction of cooling requirements after a postulated Loss of Coolant Accident.
If the malfunction cannot be rapidly corrected, the reactor will be cooled to the shutdown condition using normal cooldown procedures.
In this condition, release of fission products or damage of the fuel elements is not considered possible.
The plant operating procedures will require immediate action to effect repairs of an inoperable component and, therefore, in most cases, repairs will be completed in less than the specified allowable' repair times. The limiting times to repair are intended to:
(1) Assure that operability of the component will be restored promptly and yet, (2) allow sufficient time to effect repairs using safe and proper procedures.
The leakage rate limit for the core spray recirculation system heat exchanger was based on the consideration that the only time the heat exchanger would be used would be if a Loss of Coolant Accident were to occur.
Therefore,10 CFR Part 100 limits were usad.
The calculation was made as follows:
Allowable Water Activity =
7 DCF x x DR x t x 1.5 inh 4
r.
~
m m
Bases:
(Contd) where:
Water Activity = Drinking Water Activity at Charlevoix Resident Intake Dose (Rem) = 10 CFR 100 Dose Limits to Thyroid Reduced by a Factor of 10 To Allow for Other Dose Vectors =
30 Rem DCF = 1.h8 x 10 Rem /Ci Inhaled 4,
DR = Drinking Rate = 2,200 ml/ Day 1.5 = The Contribution Factor of I-33 to Inhaled Dose i
f
= Ingestion Uptake Factor for Iodine = 0.30 f
f Inhalation U.ptake Factor for Iodine = 0.23 h
-d t = Time = 30 Days (Assumed That Heat Exchanger Could Be Repaired Within 30 Days)
The resultant water activity = 1.57 x lo-pCi/ml.
Using this activity, the maximum allowable leakage rate can be calculated as follows:
Allowable Water Activity x Dilution in Rate = Lake Mich x Dilution Flow in Heat Exchanger a
Activity of Water That Leaks where:
Dilutio'n in Lake Michigan = 800 Dilution Flow in Heat Exchanger = h00 Gpm I
Activity of-Water That Leaks = 37 pCi/ml Based on 10% Core Melt Case and 360,000 Gallons of Water in Containment at Start' of Recirculation Phase Leakage Rate = 1.36 Gallons per Minute
m m
p E
Bases:
(Contd)
As a result of an evaluation of the effect testing frequency on emergency core cooling system reliability ("
and because a lack of test data to prove the effectiveness of the redundant (nozzle) core spray system spray distribution the surveillance requirements for the original core spray system have been increased.
In addition, time periods allowed for operation with the original. (ring) core spray system out of service have been reduced significantly. Further changes in surveillance and operability requirements will be requested prior the refuelir.g outage presently scheduled for Spring 1977 based on modifications to make the core spray systems more testable and following proof of nozzle spray effectiveness.
The fire water makeup system to the condenser hot well was provided as a temporary means of reducing peak fuel
(-
clad temperature under postulated small and intermediate sized pipe breaks until the Reactor Depressurization i
System could be completed.
It is still required until nozzle spray distribution patterns are demonstrated.
l
References:
1.
Consumers Power Company letter to Directorate of Licensing, USAEC, dated May 18, 1972.
2.
Technical Specifications Change No 26 dated July 27, 1971.
3 FHSR, Section 12.
h.
FHSR, Section 3 5
FHSR, Section 5 6.
Consumers Power Company letter to Directorate of Licensing, USAEC, dated September 22, 1972.
7 FHSR, Section 13
~
8.
" Big Rock Point Plant Hydrological Survey," Great Lakes Research Division, Special Report No 9, Ayqr, J.
C., et al, Nov 1961.
9 Consumers Power Company letter to the Secretary of the Commission, USNBC dated March 26, 1976.
10.-
Comments by the Director, Nuclear Reactor Regulation Relating to the Request for Exemption of the Big Rock Point Nuclear Power Plant From the Requirements of 10 CFR $0.h6 dated April 19, 1976.
i 4
.4, i
TABLES 11 3.1.ha AND ll.h.1.ha l'
t Instrumentation That Initiates Cores Spray ll.h.l.ha Surveillance Requirement l
ll.3.1.ha Limiting Conditions for Operation Instrument Trip 1
Trip System Limiting Conditions for Test Including Instrument Parameter Log,1c Set Point Operability Valve Initiation Calibration
~Open Core Spray e,
Valves Low Reactor Water One of Two for 2610'5" Elev Power Operation Once Every Six Months Each Major
'l-Level (b)
Each of Two (22'8" Above and Refueling, of Operation Refueling Valves in Series Core)
Operations (a)
Other Than Cold Shut-down e
Steam Drum Pressure One of Two for
>200 Psig Power Operation Once Every Six Months Each Major Low (b)
Each of Two and Refueling of Operation Refueling Valves in Series Operations (a)
Other Than Cold Shut-l down
?
notes for Tables ll.3.1.ha and 11.h.1.ha l
(a) Initiation of valve operation requires both low reactor water level coincident-with low steam drum pressure.
(b) The primary core spray system shall be available for use during refueling operations and the backup system
~
shall be closed and operation of the backup core spray valves shall be blocked or otherwise defeated while the piping section from the valves to the reactor head is dismantled.
i L
Ii I
?
P.
Add a new Section 11 3.3.h as follows:
l l
(
/
10 e
m
~
m Limiting Conditions for Operation Surveillance Requirement 11.3.3.h CONTAIm4ENT SPRAY SYSTH4 11.h.3.h CONTAINMENT SPRAY SYSTH4 Applicability:
Applicability:
Applies to the operating status of the con-Applies to the testing of the containment 1
tainment spray system.
spray system.
Objective:
Objective:
^
To assure the capability of the containment To verify the operability of the containment spray system to reduce containment pressure spray system.
in the event of a Loss of Coolant Accident.
~
Specification :
Specification:
A.
Once each operating cycle, the following A.
During power operation each of the two shall be performed:
s containment spray systems shall be operable.
1.
Automatic actuation of the contain-ment spray valve MO-706h (with water flow manually blocked).
2.
Calibration of flow instrumentation.
B.
If the condition specified in A above l
is not met, a normal orderly shutdown 3
The operability of power-operated shall be initiated within one hour and valves required for proper system the reactor shall be shut down as des-actuation shall be checkel.
~
cribed in Section 1.2 5(a) within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and shutdown as described in Section 1.2 5(a) & (b) within the fol-loving 2h hours.
B.
Surveillance of fire water supply and l
recirculation systems is governed by C.
Operability of the fire water supply l
Specification h.l.h.
and recirculation systems is governed by Specification ll.3 1.h.
l C.
Instrument channels shall te tested and calibrated as listed in Table 11.h.3.h(a).
m Bases:
The contaltiment spray systems are provided to reduce pressure in the containment following a Loss of Coolant Accident. They are initially supplied from the fire water system and later by the core spray recirculation sy stem. They are not required to be in service at reactor coolant temperatures of 212 F or below because the resultant Loss of Coolant Accident pr essere is not sufficient to pressurize the containment.
Operation of only one system is sufficient to provide the required containment spray flow. The specified flow of approximately h00 gpm is sufficient to remove post-accident core energy releases including a substan-tial chemical reaction involving hydrogen generation to below design values.
The operable status of these systems and components is demonstrated by periodic tests.
If a component is found to be inoperable, it will be possible in most cases to effect repairs and restore the system to full operability within a relatively short time.
If a single system becomes inoperable, a redundant system has been provided with the ability to perform the spray function., but it reduces the redundancy provided by plant design and limits the ability to tolerate additional equipment failures.
s 5
Initiation of the containment spray system assures that containment design pressure vill not be exceeded due to hydrogen generation assuming the core spray systems do not function.
It has been conservatively calcu-l lated that the energy release following a complete core meltdown (accuming no containment spray systems or core spray systems operate) would bring the containment pressure to approximately the design value (27 psig) about 15 minutes after the postulated accident had occurred, Subsequent LOCA analysis system modifications and regulations have limited H2 generation such that it is no longer significant and calculations show that containment spraya are not required to prevent containment design pressures from being exceeded. Thus, the automatic actuation time of the primary containment spray system has been established at 15 minutes so as to allow the operator adequate time to evaluate and block actuation, if system operation is not required.
References:
1.
FHSR, Section 3 2.
Additional information in support of Proposed Technical Specification Change No 8 dated March 17, 1966.
3 Safety Evaluation by the Research and Power Reactor Safety Branch, Division of Reactor Licensing, Consumers Power Company, Proposed Change No 8 dated April lk, 1966.
m TABLE 11.h.3.h Instrumentation That Initiates Enclosure Spray 11.h.3.h Surveillance Requirement 11.3 3.h Limiting conditions for operation Instrument Trip Trip System Conditions for Test Including Instrument 1
Parameter Logic Set M nt Operability Valve Actuation Calibration Enclosure High 1 of 2
~ $2.2 Psig (a)
Power Operation Once Every Six Months Each Major Fressure and Refueling of Operations Other Refueling Operation Than Shutdovu Time Delay (b) 1 of 1 213 Min, Power Operation Once Every Six Months Each Major sl5 Min (a) and Refueling of Operations Other Refueling Operation Than Shutdown w
(a) Primary enclosure spray setting.
(b) The time delay device requires power to perform the tripping function. This sup dy is provided by the valve control circuit.
(
i l
Q.
Add a new Section 11.h.5 3 as follows:
t
(
t li
.._ ~.-
m Limiting C3n5'iticys for Operntion Surveillance Requirement 11 3 5 3 B4ERGENCY POWFR SOURCES 11.h.5 3 E4ERGENCY POWER SOURCES Applicability:
Applicability:
Applies to the operational status of the Applies to the periodic testing requirements emergency power sources.
for the emergency power sources.
Obj ective :
Objective:
To assure the capability of the emergency To assure the operability of the emergency power sources to provide power required foi power sources to provide emergency power in emergency equipment in the event of a Loss the event of a Loss of Coolant AcciGent.
of Ceolant Accident.
Specification:
3.
Specification:
A.
The emergency power system surveillance A.
For all reactor operating conditions ex-will be performed as indicated below. In g
cept cold shutdown, there shall normally addition, components on which maintenance
\\"
be available one 138 kV line, one 46 kV has been performed will be tested.
line, one diesel generation system and one station battery system, except as fur-1.
During each operating cycle -
ther specified in 1, 2 and 3 below.
(a) Test of automatic initiation 1.
Refueling operations and related sensors and load test the emer-testing may be conducted with the gency diesel to 180-200 kW 138 kV line de-energized.
generator output.
2.
The h6 kV line or the diesel gener-(b) Test and calibrate the following ator may be out of service for repair instruments and controls associ-ated with diesel generator:
for periods up to seven days during reactor operation and for extended periods during refueling or shutdown (1) Fuel oil level.
operations.
(2) Oil.~.7ssure tripping.
(3) Water temperature tripping.
m
~
Limiting Conditions for Operation Surveillance Requirement
- 11.3.5.3 EMERGENCY POWER SOURCES (Contd) ll.h.5.3 EMERGENCY POWER SOURCES-(Contd) 3 The diesel generator fuel supply shall (h) Overspeed tripping.
be adequate for one-day operation.
(5) Battery undervoltage alaim.
h.
If the conditions specified in 2 or 3 f
above are not met, a normal orderly (c) Test tue automatic transfer of shutdown shall be initiated within station power from the 138 kV-one (1) hour and the reactor shall be line to the h6 kV line.
,~s
.i shut down as described in Section l.2 5(a) within twelve (12) hours (d) Test the automatic transfer of and shut down as described in Section power sources for the lY and 2Y 1.2.5(a) and (b) within the folleving instrument and control panels.
2h hours.
" 17 -
5 The station battery syste.n shall be i
ys operable under all conditions except a) Teststartdi;selgeneratorand for uniquely authorized periods during supply load to h80 V Bus 2B for cold shutdown. If the station battery 20 minutes' duration.
is inoperable, no actions shall be taken which result in a reactivity (b) Determine the cell voltage and addition except cooldown or might re-f p
sult in the primary coolant system being drained.
diesel generator start-up battery.
6.
An orderly hot shutdown of the reactor shall be initiated within Sh minutes (c) Test operate the rod position and the reactor shall be shut dowr; as motor generator set.
described in Section 1.2.5(a) within twelve (12) hours and shut down as de-3 Weekly -. Test start the diesel gener-scribed in Section 1.2.5(a) and (b) ator and run for warm-up period.
within the following 2h hours if the conditions of operation as specified in 5 above are exceeded.
Bases:
Normal station power can be provided by the station turbine generator, the 138 kV transmission line or the h6 kV line. These sources are adequate to provide emergency a-c power. When none of these sources is avail-able, a single emergency diesel generator rated at 200 kW starts automatically to provide emergency a-c pover i
n m
~
~
w Bases:.(Contd) to h80 V Bus 2B.
The weekly starting test is based on Manufacturer's Bulletin 33743-l' for reiubrication pro-Section of moving parts. Diesel generator initiation and output circuit breaker closure is accomplished by two voltage sensors; one to detect loss of normal power on Bus lA and the other to provide assurance of generater
. output prior to automatic closure of the generator output breaker. Additional breaker interlocks e.provided This to assure that the normal Buses lA and 2A are isolated prior to closing the generator output break,..
prevents overloading of the generator at the switching period.
s The diesel fuel oil tank is sized for two-day full load operation. One-day supply is considered adequate to provide fuel makeup.
m A single station battery supplies power for normal station services and is sized for emergency uses including valves and controls for Loss of Coolant Accidents. The battery can.be charged from the emergency diesel generator output if normal station power sources are not available.
The primary core spray valves and the primary containment spray valve are operated and controlled by power from the station battery. The backup core spray valves an,i backup containment spray valves are operatei by power frca normal station power sources or the emergency diesel generator.
U The station battery will be considered operable if it is essentially fully charged and the battery charger is The station battery has ahequate capacity to carry normal loads for 54 minutes without the be.ttery in service.
charger and still provide sufficient power for equipment required to operate during a LOCA.
If steps are taken to reduce nonessential loads during a loss of off-site power (such as part of the emergency lights) additional time (up to five hours) can be gained from the time of the loss of the charger until the battery would no longer 1.
have sufficient power for equipment required to operate during a LOCA.
+
e 4
3 i
4 9
1 1
II.
DISCUSSIONS These proposed changes are submitted to maximize the reliability of emergency core cooling performance at the Big Rock Point Plant. They are based upon the results-of the reviews performed by Consumers Power Company and the NRC These reviews are documented in the " Report on Evaluation of Adequacy staff.
of Emergency Core Cooling System" dated February 27, 1976, the additional information submitted by Consumers Power Company March 26, 1976 and the
" Comments _by the Director, Nuclear Reactor Regulation Relating to the Request for Exemption of the Big Rock Point Nuclear Power Plant from the Requirements of 10 CFR 50.L6" dated April 1976.
The primary purpose of the changes with respect to core spray system oper-ability surveillance is to increase the surveillance to the maximum extent practical, consistent with the reviews performed.
Tne deletion of the interlock between MO-706h and MO-7068 and thus automatic The first
. actuation of M0-7068 is based primarily on three considerations.
is that this interlock has some potential for tying together vital redundant power supplies. The second is, as described in the proposed Technical-Specifications Change submitted February 27, 1976, that containment sprays are not rtquired during the short term to preclude containment design pres-sure being exceeded during a Loss of Coolant Accident and adequate time is available for operator action. The third is that far greater separation 1
can be achieved by elimination of the interlock rather than installation of more complex electrical circuitry. Thus, it is proposed that the inter-lock be removed and that the backup containment spray valve (MO-7068) be remote manually actuated in the unlikely event that the automatic contain-s ment spray valve (MO-706h) does not open as designed.
The third area of change involves reduction of the nominal steady state operating pressure from lh85 psig to 1335 psig. This reduction is proposed based on a request of the staff because the analysis performed pursuant to 10 CFR 50.46 assumed a nominal operating pressure of 1335 psig. Further analysis vill be required if it is desired to increase the nominal operating pressure above 1335 psig.
l 1
l 1
18 v.
_a.
I-1 4
(-
III. CONCLUSIONS'
+
The Plant Review Committee has concluded that these proposed changes do not~ involve an unreviewed safety question. The Safety and Audit Review Board has not had an opportunity to review these changes. This review
~
.will be completed in the near future and the NRC staff vill be informed
~
of the results if they differ from those of the Plant Revlev Committee.
CONSUMERS POWER COMPANY
/
/
By C. R. Bilby, Vice Pre ent Sworn and. subscribed to before me this 10th day of May.1976.
O bbdhb it Sylvia 8. Ball, Hotary Public Jackson County, Michigan My commission expires May 18, 1976.
L I
E s
i 4
i l
i 19
~~
--.r.
..,...... ~