ML021060357
| ML021060357 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 04/11/2002 |
| From: | NRC/NRR/DLPM/LPD2 |
| To: | Southern Nuclear Operating Co |
| References | |
| TAC MB2976, TAC MB2977 | |
| Download: ML021060357 (4) | |
Text
PCIVs 3.6.1.3 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE SR 3.6.1.3.6 Verify the isolation time of each MSIV is
Ž 3 seconds and : 5 seconds.
1*
SR 3.6.1.3.7 SR 3.6.1.3.8 SR 3.6.1.3.9 Verify each automatic PCIV, excluding EFCVs, actuates to the isolation position on an actual or simulated isolation signal.
Verify each reactor instrumentation line EFCV (of a representative sample) actuates to restrict flow to within limits.
Remove and test the explosive squib from each shear isolation valve of the TIP System.
7r SR 3.6.1.3.10 Verify the combined leakage rate for all secondary containment bypass leakage paths is - 0.009 La when pressurized to SPa.
FREQUENCY In accordance with the Inservice Testing Program 18 months 18 months 18 months on a STAGGERED TEST BASIS In accordance with the Primary Containment Leakage Rate Testing Program (continued)
Amendment No.
171 HATCH UNIT 2 I
i I
I 3.6-14
PCIVs B 3.6.1.3 BASES SURVEILLANCE REQUIREMENTS (continued)
HATCH UNIT 2 SR 3.6.1.3.8 This SR requires a demonstration that each reactor instrumentation line excess flow check valve (EFCV)
(of a representative sample) is OPERABLE by verifying that the valve reduces flow to within limits on an actual or simulated instrument line break condition.
(The representative sample consists of an approximately equal number of EFCVs, such that each EFCV is tested at least once every 10 years [nominal].
In addition, the EFCVs in the sample are representative of the various plant configurations, models, sizes, and operating environments.
This ensures that any potentially common problem with a specific type of application of EFCV is detected at the earliest possible time.)
This SR provides assurance that the instrumentation line EFCVs will perform as designed.
The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power.
Operating experience has shown that these components usually pass this Surveillance when performed at the 18 month Frequency.
Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.
(The nominal 10 year interval is based on performance testing as discussed in NEDO-32977-A, "Excess Flow Check Valve Testing Relaxation" (Ref.
8).
Furthermore, any EFCV failures will be evaluated to determine if additional testing in that test interval is warranted to ensure overall reliability is maintained.
Operating experience has demonstrated that these components are highly reliable and that failures to isolate are very infrequent.
Therefore, testing of a representative sample was concluded to be acceptable from a reliability standpoint.)
Any excess flow check valve that fails to check flow during its surveillance test will be documented in the Hatch corrective action program as a surveillance test failure.
The failure will be evaluated and corrected and, if the valve is repaired and not replaced, it will be added to the next cycle's surveillance.
SR 3.6.1.3.9 The TIP shear isolation valves are actuated by explosive charges.
An in place functional test is not possible with this design.
The explosive squib is removed and tested to (continued)
_REVISION 31 D
O.
U--f=.I
PCIVs B 3.6.1.3 BASES SURVEILLANCE SR 3.6.1.3.9 (continued)
REQUIREMENTS provide assurance that the valves will actuate when required.
The replacement charge for the explosive squib shall be from the same manufactured batch as the one fired or from another batch that has been certified by having one of the batch successfully fired.
The Frequency of 18 months on a STAGGERED TEST BASIS is considered adequate given the administrative controls on replacement charges and the frequent checks of circuit continuity (SR 3.6.1.3.4).
SR 3.6.1.3.10 This SR ensures that the leakage rate of secondary containment bypass leakage paths is less than the specified leakage rate.
This provides assurance that the assumptions in the radiological evaluations that form the basis of the FSAR (Ref.
- 3) are met.
The secondary containment bypass leakage paths are: 1) main steam condensate drain, penetration 8; 2) reactor water cleanup, penetration 14; 3) equipment drain sump discharge, penetration 18; 4) floor drain sump discharge, penetration 19; and 5) chemical drain sump discharge, penetration 55.
The leakage rate of each bypass leakage path is assumed to be the maximum pathway leakage (leakage through the worse of the two isolation valves) unless the penetration is isolated by use of one closed and de-activated automatic valve, closed manual valve, or blind flange.
In this case, the leakage rate of the isolated bypass leakage path is assumed to be the actual pathway leakage through the isolation device.
If both isolation valves in the penetration are closed, the actual leakage rate is the lesser leakage rate of the two valves.
The Frequency is required by the Primary Containment Leakage Rate Testing Program (Ref.
7).
SR 3.6.1.3.11 The analyses in References I and 4 are based on leakage that is less than the specified leakage rate.
Leakage through each MSIV must be
- 100 scfh, and a combined maximum pathway leakage : 250 scfh for all four main steam lines when tested at Ž 28.8 psig.
In addition, if any MSIV exceeds the 100 scfh limit, the as left leakage shall be < 11.5 scfh for that MSIV.
(continued)
HATCH UNIT 2 B 3.6-28 REVISION 31
PCIVs B 3.6.1.3 BASES SURVEILLANCE SR 3.6.1.3.11 (continued)
REQU IREM ENTS The Frequency is required by the Primary Containment Leakage Rate Testing Program.
SR 3.6.1.3.12 The valve seats of each 18 inch purge valve (supply and exhaust) having resilient material seats must be replaced every 18 months.
This will allow the opportunity for repair before gross leakage failure develops.
The 18 month Frequency is based on engineering judgment and operational experience which shows that gross leakage normally does not occur when the valve seats are replaced on an 18 month Frequency.
SR 3.6.1.3.13 The Surveillance Requirement provides assurance that the excess flow isolation dampers can close following an isolation signal.
The 18 month Frequency is based on vendor recommendations and engineering judgment.
Operating experience has shown that these dampers usually pass the Surveillance when performed at the 18 month Frequency.
Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.
REFERENCES
- 1.
FSAR, Chapter 15.
- 2.
Technical Requirements Manual.
- 3.
FSAR, Section 15.1.39.
- 4.
FSAR, Section 6.2.
- 5.
10 CFR 50, Appendix J, Option B.
- 6.
NRC No.93-102, "Final Policy Statement on Technical Specification Improvements," July 23, 1993.
- 7.
Primary Containment Leakge Rate Testing Program.
- 8.
NEDO-32977-A, "Excess Flow Check Valve Testing Relaxation."
I REVISION 31 HATCH UNIT 2 B 3.6-29