ML030910459

TS Bases Control Program

ML030910459
Person / Time
Site:	Monticello
Issue date:	03/31/2003
From:	NRC/NRR/DLPM
To:
References
TAC MB4919
Download: ML030910459 (2)

Text

Bases 4.7 (Continued):

On September 26, 1995, Regulatory Guide 1.163 became effective providing requirements of 10 CFR 50, Appendix J, Option B. Monticello has adopted guidance on performance based testing to the Primary Containment Leakage Rate Testing Program. This program is modified 10 CFR Part 50, Appendix J, Option B, and a Section 9.2.3: The first Type A test performed after March 1993 Type A test by the following exception: NEI 94-01, Rev. 0, shall be performed no later than March 2008.

Maintaining primary containment integrity requires compliance with the visual examinations and leakage rate test requirements of the Primary Containment Leakage Rate Testing Program. Failure to meet valve resilient seal leakage testing or main steam isolation valve leakage air lock leakage testing, primary containment purge does not necessarily result in a failure of this SR. The impact of the failure to meet these SRs must be evaluated against the Type A, B and C acceptance criteria of the Primary Containment Leakage Rate Testing Program.

Maintaining primary containment air locks requires compliance with the leakage rate testing requirements of the Primary Containment Leakage Rate Testing Program. This SR reflects the leakage leakage (Type B leakage tests). The periodic testing requirements verify rate testing requirements with respect to air lock fraction of the overall primary containment leakage rate. The frequency that the air lock leakage does not exceed the allowed is required by the Primary Containment Leakage Rate Testing Program.

The SR has been modified by two footnotes. Note

• states that an inoperable successful performance of the overall air lock leakage test. This is considered air lock door does not invalidate the previous reasonable since either air lock door is capable of providing a fission barrier in the event of a DBA. Note **has been added to the acceptance criteria which is applicable to Primary Containment Integrity. this SR requiring the results to be evaluated against This ensures that the air lock leakage is properly accounted for in determining the combined Type B and C primary containment leakage.

The air lock interlock mechanism is designed to prevent simultaneous opening of both doors in the air lock. Since both the inner and outer doors of an air lock are designed to withstand the maximum expected post closure of either door will support primary containment integrity. Thus, the interlock accident primary containment pressure, integrity while the air lock is being used for personnel transit in and out of the feature supports primary containment containment. Periodic testing of the interlock demonstrates that the interlock will function as designed and that the simultaneous inadvertently occur. Due to the purely mechanical nature of this interlock, and inner and outer door opening will not given that the interlock mechanism is not normally challenged when primary containment air lock door is used for entry and exit (procedures require strict adherence to single door opening), this test is only required to be performed every 24 months. The 24 month frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage, and the potential for loss of primary containment integrity if the Surveillance were performed with the reactor at power. The 24 month frequency is based on engineering judgment and is considered adequate given that the interlock is not challenged during the use of the air lock.

4.7 BASES NEXT PAGE IS PAGE 188 185 Amendment No. 950a,4 32, 134

6.8.J - RESERVED K. Technical Specifications (TS) Bases Control Program This program provides a means for processing changes to the Bases of these Technical Specifications.

1. Changes to the Bases of the TS shall be made under appropriate administrative controls and reviews.

2. Changes to Bases may be made without prior NRC approval provided the changes do not involve either of the following:

a. a change in the TS incorporated in the license; or

b. a change to the USAR or Bases that requires NRC approval pursuant to 10 CFR 50.59.

3. The Bases Control Program shall contain provisions to ensure that the Bases are maintained consistent with the USAR.

4. Proposed changes to the Bases that involve changes as described reviewed and approved by the NRC prior to implementation. Changes in a. or b. of Specification 6.8.K.2 above shall be, approval shall be provided to the NRC on a frequency consistent with to the Bases implemented without prior NRC 10 CFR 50.71 (e).

6.8.L - RESERVED M. Primary Containment Leakage Rate Testing Program

1. This program shall establish the leakage rate testing of the containment as required by 10 CFR 50.54(o) and 10 CFR Part 50, Appendix J, Option B, as modified by approved exemptions.

guidelines contained in Regulatory Guide 1.163, "Performance-Based This program shall be in accordance with the Containment 1995, as modified by the following exception: NEI 94-01, Rev. 0, "Industry Leak-Test Program," dated September Option of 10 CFR 50, Appendix J." Guideline for Implementing Performance-Based J Section 9.2.3: The first Type A test after the March 1993 Type A test shall be performed no later than March 2008. J

2. The calculated peak containment internal pressure for the design basis loss of coolant accident, Pa, is 42 psig. The containment design pressure is 56 psig.

6.8 258 Amendment No. 120; 22-32, 134