ML20245A312

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Proposed Tech Specs Re Containment Purge & Vent Valves
ML20245A312
Person / Time
Site: Cooper Entergy icon.png
Issue date: 04/19/1989
From:
NEBRASKA PUBLIC POWER DISTRICT
To:
Shared Package
ML20245A309 List:
References
NUDOCS 8904250139
Download: ML20245A312 (6)
v • d • e


Text

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LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.7.A.1 (cont'd) 4.7.A (cont'd)

f. During reactor isolation conditions, 2. Leak Rate Testinn the reactor pressure vessel shall be depressurized to less than 200 psig at a. Integrated leak rate test (ILRT's) normal cooldown rates if the pool shall be performed to verify primary temperature reaches 120*F. containment integrity. Primary containment integrity is confirmed if
2. Containment Integrity the leakage rate does not exceed the equivalent of 0.635 percent of the l a. Primary containment integrity shall be primary containment volume per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> maintained at all times when the at 58 psig.

reactor is critical or when the

  • reactor water temperature is above b. Integrated leak rate tests may be 212*F and fuel is in the reactor performed at either 58 psig or 29 psig, vessel except while performing "open the leakage rate test period, extending vessel" physics tests at power levels to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of retained internal 4

not to exceed 5 MW(t). pressure. If it can be demonstrated to  ?

the satisfaction of those responsible

b. When Coolant Temperature is above for the' acceptance of the containment 1

212*F, the drywell and suppression structure that the leakage rate can be chamber purge and vent system may be accurately determined during a shorter in operation for up to 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> per test period, the agreed upon shorter calendar year with the supply and period may be used.

exhaust 24-inch isolation valves in one supply.line and one exhaust line Prior to initial operation, integrated open for containment inerting, leak rate tests must be performed at 58 deinerting, or pressure control. and 29 psig (with the 29 psig test being performed prior to the 58 psig If venting or purging is through test) to establish the allowabla leak Standby Cas for such operations, then rate, 4 (in percent of containment both Standby Gas Treatment Systems volume per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />) at 29 psig as the I shall be operable and only one Standby lesser of the following values.

Gas Treatment System is to be used.*

( La is 0.635. percent)

  • Not applicable to valves open during venting or purging provided such Ic0.635 ,*

venting or purging utilizes the 2-inch Lom bypass line(s) around the applicable inboard purge exhaust isolation for h* s 0.7 valve (s) with the inboard valve (s) in -

b^*

a closed condition.

where km - measured ILR at 29 psig Lom - measured ILR at 58 psig, and i Lm r 1.0 1

l Lom L, - 0 . 6 3 5 P, 1/ 2 Po

-160-8904250139 DR 890419 p ADOCK 05000298 PDC

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[ TABLE 3.7.4

. PRIMARY. CONTAINMENT TESTABLE ISOLATION VALVES TEST PEN. NO. VALVE NUMBERS MEDIA X-7A MS-AO-80A'and MS-AO-86A, Main Steam Isolation Valves Air

_[ X-7B MS-A0 80B and MS-AO-86B, Main Steam Isolation Valves Air X-7C _MS-AO-80C and MS-AO-86C, Main Steam Isolation Valves Air X 7D MS-AO-80D and MS-AO 86D, Main Steam Isolation valves Air.

X-8. MS-MO-74 and MS MO-77 Main Steam Line Drain Air X-9A- RF-15CV and RF-16CV, Feedwater Check Valves Air X-9A- RCIC AO-22, RCIC-MO-17, and RWCU-15CV, RCIC/RWCU Connection to Feedwater Air X-9B RF-13CV and RF-14CV, Feedwater Check Valves Air

-X-9B HPCI-AO-18 and HPCI.MO-57, HPCI Connection to Feedwater Air X-10 RCIC-MO-15 and RCIC-MO-16, RCIC Steam Line Air

.X-ll HPCI-MO-15 and HPCI-MO-16, HPCI Steam Line Air

'X 12' RHR-MO-17'and RHR-MO-18, RHR Suction Cooling Air X-13A RHR-M0-25A and RHR-MO-27A, RHR Supply to RPV Air X-13B RHR-MO-25B and RHR-MO-27B, RHR Supply to RPV Air X-14 RUCU-MO-15 and RWCU MO-18, Inlet to RWCU System Air X 16A CS-MO-11A and CS-MO-12A, Core Spray to RPV Air X-16B CS-MO-llB and CS-MO 12B, Core Spray to RPV Air X 18 RW-732AV and RW-733AV, Drywell Equipment Sump Discharge Air X-19 RW-765AV and RW-766AV, Drywell Floor Drain Sump Discharge Air X-25 (Note 1) PC-232MV and PC 238AV, Purge and Vent Supply to Drywell Air X-25 ACAD-1305MV and ACAD-1306MV, Supply to Drywell Air X-26 (Note 1) PC-231MV, PC-246AV, and PC-306 MV Purge and Vent Exhaust from Drywell Air X-26 ACAD-1310MV, Bleed from Drywell Air

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TABLE 3.7.4 (page 2) h PRIMARY CONTAINMENT TESTABLE ISOLATION VALVES TEST PEN. NO. VALVE NUMBERS MEDIA X-39A RRR-MO-26A and RHR-MO-31A, Drywell Spray Header Supply Air X-39B RHR-MO-26B and RHR-MO-31B, Drywell Spray Header Supply Air X-39B ACAD-1311MV and ACAD 1312MV, Supply to Drywell Air X-41 RRV-740AV and RRV-741AV, Reactor Water Sample Line Air X-42 SLC-12CV and SLC-13CV, Standby Liquid Control Air X-205 (Note 1) PC-233MV and PC-237AV, Purge and Vent Supply to Torus Air X-205 PC-13CV and PC-243AV, Torus Vacuum Relief Air X-205

  • PC-14CV and PC-244.GV, Torus Vacuum Relief Air X-205 ACAD-1303MV and ACAD-1304MV, Supply to Torus Air X-210A RCIC-MO-27 and RCIC-13CV, RCIC Minimum Flow Line Air X-210A RER-MO-21A, RHR to Torus Air X-210A RER-MO-16A, RHR-10CV, and PWR-12CV, RHR Minimum Flow Line Air X-210B RHR-M0-21B, RHR to Torus Air X-210B HPCI-17CV and HPCI-M0-25, HPCI Minimum Flow Line Air X-210B RHR-MO-16B, RHR-llCV, and RHR-13CV, RHR Minimum Flow Line Air X-210A and 211A .RHR-MO-34A, RHR-M0-38A, and RHR-MO-39A, RHR to Torus Air X-210B and 211B RHR-MO-34B, RHR-MO-38B, and RHR-MO-39B, PJiR to Torus Air X 211B ACAD-130lMV and ACAD-1302MV, Supply to Torus Air X-212 RCIC-15CV and RCIC-37, RCIC Turbine Exhaust Air X-214 HPCI-15CV and HPCI-44, HPCI Turbine Exhaust Air X-214 HPCI AO-70 and HPCI-AO-71, HPCI Turbine Exhaust Drain Air X 214 RHR-MO-166A and RHR-M0-167A RHR Heat Exch. Vent Air X 214 RHR-MO-166B and RHR-MO-167B RHR Heat Exch. Vent Air X-220 (Note 1) PC-230MV, PC-245AV, and PC-30SMV Purge and Vent Exhaust from Torus Air X-220 ACAD-1308MV, Bleed from Torus Air X-221 RCIC-12CV and RCIC-42, RCIC Vacuum Line Air X-222 HPCI-50 and HPCI-16CV, HPCI Turbine Drain Air

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TABLE 3.7.4 (page 3)

PRIMARY CONTAINMENT TESTABLE ISOLATION VALVES

, TEST PEN. NO. VALVE NUMBERS MEDIA X-223A CS-MO-26A and CS-MO-5A, Core Spray Test and Minimum Flow Air X-223B CS-MO-26B and CS-MO-5B, Core Spray Test and Minimum Flow ' Air X-225A-D RHR-MO-13A, RHR-MO-13C, RHR-MO-13B, RHR-M0-13D, RHR Suction From Torus Air X-224 RCIC-MO-41, RCIC Suction From Torus Air X-226 HPCI-MO-58, HPCI Suction From Torus Air X,227A, B CS-MO-7A.and CS-MO-7B, Core Spray Suction From Torus Air Notes'to Table 3.7.4

1. Once per operating cycle, while shutdown, the devices which limit the maximum-opening angle to 60* shall*be verified functional for the following valves:

PC-230MV PC-231MV PC-23.2MV PC-233MV .

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'" -3.7;A'& ,.7,.A BASES.(cont'd)

!: check of the' temperature and volume is adequate to assure that adequate heat removal capability is present.

The interiors of the drywell.and suppression chamber are painted to prevent rusting.

The inspection of the paint during each major refueling outage, approximately once per year, assures the paint is intact. Experience with this type of paint at fossil fueled generating stations indicates that the, inspection interval is adequate.

The intent of Specification 3.7. A.2.b is to reduce the probability of a LOCA occurrence when the 24-inch purge and vent valves. are open in series. These valves are normally closed during power operation to minimize reliance on the valve operators to ensure containment integrity. The requirements for Standby Gas is due to the damage the filters would experience from excessive difference pressure caused by a LOCA with the -

24-inch exhaust valves open in series from the drywell or suppression chamber. This specification does allow venting with the inboard exhaust bypass valve and the outboard exhaust valve both open in series and the time does not count against the yearly limit. '

.The NRC has accepted the determination that due to the small size of the bypass valve, there is no chance of damage to the filters if a LOCA . occurs while venting the containment through the bypass with a SBGT system on line. The term " calendar year" is a period of time beginning on January 1 and ending on December 31 for each numbered year.

3.7.A.3 & 4 and 4.7.A.3 & 4 VACUUM BREAKERS The purpose of the vacuum relief valves is to equalize the pressure between the drywell and suppression chamber and reactor building so that the structural integrity of the. .

containment is maintained. The vacuum relief system from the pressure suppression chamber to reactor building consists of two 100% vacuum relief breakers (2 parallel sets of 2 valves in series). Operation of either system will maintain a pressure i+J differential of less than 2 psi, the external design pressure. One valve may be out of service for repairs for a period of 7 days. If repairs cannot be completed within 7 days the reactor coolant system is brought to a condition where vacuum relief is no longer required.

The capacity of the 12 drywell vacuum relief valves are sized to limit the pressure differential between the suppression chamber and drywell during post-accident dry-well cooling operations to well under the design limit of 2 psi. They are sized on the basis of the Bodega Bay pressure suppression system tests. The ASME Boiler and Pressure Vessel Code,Section III, Subsection B, for this vessel allows a 2 psi differential; therefore, with three vacuum relief valves secured in the closed position and 9 operable valves, containment integrity is not impaired.

3.7.A.5 and 4.7.A.5 OXYGEN CONCENTRATION Safety Guide 7 assumptions for Metal-Water reaction result in hydrogen concentration in excess of the Safety Guide 7 flammability limit. By keeping the oxygen concentration less than 4% by volume the requirements of Safety Guide 7 are satisfied.

The occurrence of primary system leakage following a major refueling outage or other scheduled shutdown is much more probable than the occurrence of the loss-of-coolant accident upon which the specified oxygen concentration limit is based. Permitting access to the drywell for leak inspections during a startup is judged prudent in terms

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of the added plant safety offered without significantly reducing the margin of safety.

Thus, to preclude the possibility of starting the reactor and operating for extended period of time with significant leaks in the primary system is at or near rated operating temperature and pressure. The 24-hour period to provide inerting is judged to be sufficient to perform the leak inspection and establish the required oxygen concentration.

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4 3.7.D & 4.7.D BASES (cont'd) "

l results in a failure probability of 1.1 x 10~7 that a line will not isolate.

.More frequent testing for valve operability results in a greater assurance that the valve will be operable when needed.

In order to assure that the doses that may result from a steam line break do not exceed the 10CFR100 guidelines, it is necessary that no fuel rod perforation resulting from I the accident occur prior to closure of the main steam line isolation valves. Analyses indicate that fuel rod cladding perforations would be avoided for main steam valve closure times, including instrument delay, as long as 10.5 seconds. The primary containment is penetrated by several small diameter instrument lines connected to the reactor coolant system. Each instrument line contains a 0.25 inch restricting orifice inside the primary containment and an excess flow check valve outside the primary containment. A program for periodic testing and examination of the excess flow check valves is performed as follows:

, 1. Vessel at pressure sufficient to actuate valves. This could be at time of vessel hydro following a refueling outage.

2. Isolate sensing line from its instrument at the instrument manifold.
3. Provide means for observing and collecting the instrument drain or vent valve flow.
4. Open vent or drain valve.
a. Observe flow cessation and any leakage rate.
b. Reset valve after test completion.
5. The head seal leak detection line cannot be tested in this manner. This valve will not be exposed to primary system pressure except under unlikely conditions of seal failure where it could be partially pressurized to reactor pressure. i Any leakage path is restricted at the source and therefore this valve need not be tested. This valve is in a sensing line that is not safety related.
6. Valves will be accepted if a marked decrease in flow rate is observed and the letkage rate is acceptable.

The operators for containment vent / purge valves PC-230MV, PC-231MV, PC-232MV, and PC-233MV have devices in place to limit the maximum opening angle to 60 degrees. This has been done to ensure these valves are able to close against the maximum differential pressure expected to occur during a design basis LOCA.

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