ML19338C965
| ML19338C965 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 08/03/1977 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19338C964 | List: |
| References | |
| NUDOCS 8009100998 | |
| Download: ML19338C965 (7) | |
Text
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O REACT 07. COOLANT SYSTEM 3 /4.4.2 SAFETY VALVES LIMITING CONDITION FOR OPERATION 3.4.2 At lear, the following reactor coolant system code safety valves and safety-relief valves shall be operable with lift settings within + 1% of the indicated pressures, i
I (2)* Safety valves 0 (1240) psig (3) Safety-relief valves 0 (1100) psig I
(3) Safety-relief valves 0 (1090) psig (3) Safety-relief valves 0 (1080) psig j
APPLICABILITY:
With Average Coolant Temperature > 212*F or the Mode Switch in Run, or Startup/ Hot Standby.
ACTION:
With one or more reactor coolant system code safety valve (s) or a safety-relief valve (s) inoperable either restore the valve (s) to operable status within 15 minutes or be shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and reduce Average Coolant Temperature to 5 212 F within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
SURVEILLANCE RE0VIREMENTS 4.4.2.1 In addition to the applicable ASME Boiler and Pressure Vessel Code,Section XI requirements, each safety-relief valve shall be demonstrated operable:
a.
At least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, by verifying bellows integrity
.through instrument indication.
b.
Until March 1,1979, at least once per 18 months by:
1.
Manually opening each remotely operated safety-relief valve with the reactor at or below 5% rated power and at nominal operating pressure, and verifying that either:
a.
The turbine bypass valve (s) indicate a compensating valve movement, or b.
The reactor coolant system pressure decreases by an amount equivalent to the valve pressure relieving capacity for the test conditions.
l ';ces not include installed spare safety valves.
,8009100 f
REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued) 2.
Conducting a visual inspection of the safety-relief valve line restraints in the torus to verify structural integrity for continued operation.
c.
After March 1,1979, by performance of the following test program:
1.
Manually opening each remotely operated safety-relief valve in accordance with the test schedule of Table 4.4-10 with the reactor at or below 5% rated power and a steam at nominal operating pressure and verifying that either:
a.
The turbine bypass valve (s) indicate a compensating valve movement, or b.
The reactor coolant system pressure decreases by an amount equivalent to the valve pressure relieving capacity for the test conditions.
2.
The initial Next Required Test Interval of Table 4.4-10 shall be determined by the number of remotely operated relief and safety-relief valves found inoperable from September 1,1977 to March 1,1979.
3.
The initial valve tests of Table 4.4-10 shall be completed by, the earlier of:
a.
The completion of the next refueling outage occurring after March 1,1979, or b.
The time period defined by March 1,1979 plus the initial test interval, determined above.
4.
At least once per 18 month's, by conducting a visual inspection of the safety-relief valve line restraints in the torus to verify structural integrity for continued operation.
4.4.2.2 Each safety valve and the safety valve function of each safety-relief valve shall be demonstrated operable per the requirements of the ASME Boiler and Pressure Vessel Code (
) Edition and Addenda through
(
).
l
i.
TABLE 4.4-10 REMOTELY OPERATED RELIEF AND SAFETY-RELIEF VALVE TEST SCilEDULE NUMBER OF REMOTELY OPERATED RELIEF AND SAFETY-RELIEF VALVES NEXT REQUIRED FOUND INOPERABLE DURING TESTING OR TEST INTERVAL **
TEST INTERVAL
- 0 18 months + 25%
1 184 days T 25%
2 92 days 125%
>3 31 days
+ 25%
e
- The required test interval shall not be lengthened more than one step at a time.
Early tests may be performed prior to entering the "next required test interval" (i.e., in advance of the nominal time less the negative 25% tolerance band).
Early tests may be used as a new reference point for tests of the same interval, however, they are not acceptable for lengthening the test interval.
- Setpoint drif t is not considered to be a valve failure for the purposes of this test schedule.
b
4 3 /4.4 REACTOR COOLANT SYSTEM BASES 3 /4.4.2 SAFETY VALVES The reactor coolant system safety valves operate to prevent the reactor coolant system from being pressurized above the Safety Limit of psig.
Each safety valve is designed to relieve lbs per hour at the valve set point.
The system is designed to meet the ASME Boiler. and Pressure Vessel Code requirements that the nuclear system relief valves shall function to prevent opening of the safety valves.
Although the safety valve function is not expected to be required under the most limiting transient, an inoperable valve requires shutdonn in order to comply with ASME Code requirements.
The testing frequency applicable to the relief valve function of the safety-relief. valves is provided to ensure operability and demonstrate reliability of the valves. The required testing interval varies with observed valve failures. The number of inoperable valves found during both operation and testing of these valves determines the time interval for the next required test of these valves.
Early tests may be performed prior to entering the next required test interval (i.e., in advance of the nominal time less the negative 25% tolerance band).
Early tests may be used as a new reference point for tests of the same time interval, however, they are not acceptable for lengthening the test interval since they were not performed witnin the +25% tolerance band as required by Table 4.4-10.
Demonstration of the safety valves' lift settings will occur only during shutdown and will be performed in accordance with the provisions of Section XI of the ASME Boiler and Pressure Yessel Code.
i He MP
EMERGENCY CORE COOLING SYSTEMS i
AUTOMATIC DEPRESSURIZATION SYSTEM LIMITING CONDITION FOR OPERATION 3.5.2 The Automatic Depressurization System ( ADS) shall be OPERABLE with at least (6)* OPERABLE ADS valves.
I APPLICABILITY:
With Average Coolant Temperature > 212*F or the Mode Switch in Run, or Startup/ Hot Standby.
ACTION:
)
a.
With one of the above required ADS valves inoperable, operation may centinue provided the actuation logic of the remaining ADS valves is operable and the CSS and LPCI systems are operable,
+
and the HPCI system is demonstrated operable within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />; restore the inoperable ADS valve to operable status within 14 days or be shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and reduce the Average Coolant Temperature to 3 212*F within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
b.
With two or more of the above required ADS valves inoperable, i
be shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and reduce the Average Coolant Temperature to 1212*F within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
SURVEILLANCE RE0'JIREMENTS
)
4.5.2 In addition to the applicable ASME Boiler and Pressure Yessel Code, j
Section XI requirements, the ADS shall be demonstrated cperable:
l l
a.
At least once per 18 months by performance of a system i
functional test which includes simulated automatic actuation t
througn the automatic depressurization sequence, but excluding valve actuation.
b.
Until March 1,1979, at least once per 18 months by:
l.
Manually opening each ADS valve with the reactor at or below 57, rated power and at ncminal operating pressure and verifying that either:
i a.
The turbine bypass valve (s) indicate a compensating valve movement, or b.
The reactor coolant system pressure decreases by an amount equivalent to the v'alve pressure relieving capacity for the test conditions.
i ' Number of Aus valves to be consistent with ECCS analysis.
j l
EMERGENCY CORE COOLING SYSTEMS AUTOMATIC DEPRESSURIZATION SYSTEM SURVEILLANCE RE0UIREMENTS (Continued) i 2.
Conducting a visual inspection of the safety-relief and relief valve line restraints in the torus to verify structural integrity for continued operation.
c.
Af ter March 1,1979, by performance of the following test program:
i 1.
Manually opening each ADS valve in accordance with the test schedule of Table 4.4-10 with the reactor at or below 5% rated power and at nominal operating pressure and verifying that either:
a.
T,he turbine bypass valve (s) indicate a compensating valve movement, or b.
The reactor coolant system pressure decreases by an amount equivalent to the valve pressure relieving capacity for the test conditions.
2.
The initial Next Required Test Interval of Table 4.4-10 1
shall be determined by the number of remotely operated relief and safety-relief valves found inoperable from September 1,1977 to March 1,1979.
3.
The initial valve tests of Table 4.4-10 shall be completed by, the earlier of:
i a.
The completion of the next refueling outage occurring after March 1,1979, or b.
The time period defined by March 1,1979 plus the initial test interval,. determined above.
4.
At least once per 18 months by conducting a visual insoet, tion of tne safety-relief and relief valve line restraint; in the j
torus to verify structural integrity for continued operation.
I e
g vv
3 /4.5 EMERGENCY CORE COOLING SYSTEM i
BASES 3 /4. 5.2 AUTOMATIC DEPRESSURIZATION SYSTEM (ADS)
Upon failure of the HPCIS to function properly after a small i
break loss-of-coolant accident, the ADS automatically causes the safety-relief valves to open, depressurizing the reactor so that flow from the low pressure cooling systems can enter the core in time to limit fuel cladding temperature to less than 2200*F.
ADI is conservatively required to be operable whenever reactor vessel
~
pressure exceeds (150) psig even though low pressure cooling systems provide adequate core cooling up to (350) psig.
ADS automatically controls (7) safety-relief valves although the safety analysis only takes credit for (6).
Therefore it is appropriate to permit (one) valve to be out-of-service without materially a
i reducing system reliability.
The testing frequency applicable to ADS valves is provided to 1
ensure operability and demonstrate reliability of the valves.
Tne required testing interval varies with observed valve failures. The number of inoperable valves found during both operation and testing of these valves determines the time interval for tne next requirec test of these valves.
Early tests may-be performed prior to enterir; the next required test interval (i.e., in advance of the ncminal ti e less the negative 25% tolerance band).
Early tests may be usea as a ne-reference point for tests of the same time interval, however, tney are not acceptable for lengthening the test interval since they were not performed within the +25% tolerance band as required by Table 4.4-10.
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