ML20202J091

Safety Evaluation Accepting Proposed Exemption,Which Meets Special Circumstance Given in 10CFR50.12(a)(2)(ii)

ML20202J091
Person / Time
Site:	Millstone
Issue date:	12/02/1997
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20202J084	List: ML20202J079 ML20202J085 ML20202J091
References
NUDOCS 9712110039
Download: ML20202J091 (4)

Text

-- - _ __ __ .- . . - - _ - - - -. -- -

r

, per:g y UNITED STATES

,j g NUCLEAR REGULATORY COMMISSION  !

o 2 WASHINGTON, D.C. 2004H001

%...../ i SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION TEMPORARY EXEMPTION FROM 10 CFR PART 50. APPENDIX J. TYPE B AND TYPE C LOCAL LEAK RATE TESTING OF CONTAINMENT PENETRATI0f6 NORTHEAST NilCLEAR ENERGY COMPANY MILLSTONE NUCLEAR POWER STATION. UNIT NO. 1 QQRET NO. 50-245

1.0 INTRODUCTION

By letter dated October 16, 1997, the Northeast Nuclear Energy Company (NNECO or the licensee) requested a one-tirro scheduler exemption from the requirements of 10 CFR Part 50, Appendix J, Option A, Sections Ill.D.2.(a) and Ill.D.3. Appendix J requires these tests to be performed at every refueling outage with the interval not to exceed 2 years. -The temporary scheduler exemption would extent the interval for Type B and Type C local leak rate testing (LLRT) of containment penetrations at the Millstone Nuclear Power Station, Unit No.1 (MNPSI) beyond the 2-year limit of 10 CFR Part 50, Appendix J until containment integrity is required for startup from the current refueling outage (i.e., Refueling Outage Cycle 15 (RF015)).

The last Type B and Type C tests were performed shortly after MNPSI was shut down for RF015 on November 4, 1995. Therefore, the 2-year maximum interval between tests specified in 10 CFR Part 50, Appendix J require an additional test in November 1997. However, MNPSI has not operated since the November 1995 tests and is not anticipated to return to operation until June 1998 at the earliest. Therefore, the licensee requested a one-time scheduler exemption to allow for exceeding the 2-year maximum interval specified in the regulations and insteari perform the Type B and Type C testing prior to the plant's restart.

Section 50.12 of Title 10 of the Code of Federal Reaulations states that the Commission may grant exemptions from the requirements of 10 CFR Part 50 provided certain conditions are met. As stated in 10 CFR 50.12(a)(1),

exemptions may be granted which are authorized by law, will not present an undue risk to the public health and safety, and are consistent with the common defense and security. In addition to these general requirements, the proposed exemptions must meet at least one of the special circumstances given in 10 CFR 50.12(a)(2).

~

9712110039 971202 PDR ADOCK 05000245 P PDR Ehclosure 2

2.0 BCKGR0VND l1 NNECO provided the following justification for the requested exemptions l 1.  !

i Type 0 and C tests began and were completed in the '

beginning months of the current outage [RF015). Primary containment intenrity has not been requsred since that time.

Commencing the tests again in November 1997 rather than to just prior to the ILRT [ integrated leak rate test) would not benefit public health and safety because the penetrations and containment isolation valves have not seen nor been challenged by operating conditions during the 2-year interval.

2. Since all three units at Hillstone Station are currently in a shutdown mode, with on-going work, NNECO's personnel resources needed to fully implement a revised and expanded Appendix J program for Millstone Unit No. I are being strained. We believe it would be more appropriate to spend l the additional time that a scheduler exemption would provide to focus those resources on improving the Appendix J program, and completing all Appendix J-related modifications and procedure changes prior to testing, rather than performing testing that will be required again prior to startup.

3. In order to avoid exceeding this 2-year interval, outage work may need to be scheduled around the testing schedule without regard for the impact on other outage work. As an example, a system in wet lay-up may have to l'e drained down to perform Ap)endix J testing to meet the scheduler limit and impact worc being done on the system or systems it supports.

Rescheduling the test to a more suitable time later in the outage would allow work to proceed without inipacting'the overall outage schedule.

4. Testing must be performed close to startup so that the LLRTs required in RF016 do not require initiation prior to'the scheduled RF016 start date. It is probable that a shutdown would be required prior to completing Cycle 16 burnup to perform testing. This is a personnel radiation exposure concern as well as a cost concern. Upon completion of burnup, testing would begin anew during RF016 to avoid a similar situation during operating Cycle 17.

5. Without an exemption, a second testing of many of the containment isolation valves and penetrations would have to be performed as close as practical to startup in RF015. This would cause some increase in exposure and add cost and expense in terms of manpower resources.

i

. 1

6. ANSI recognize that when primary containm/ANS ent integrity standards" *8Has in this case, the test is not required, ,

interval may be extended provided all deferral testing is ,

successfully completed prior to the time containment integrity l is required. What the standard recognizes is there is no benef.it to public health and safety by performing tests earlier than needed since primary containment is not needed and the

)enetratione and containment isolation valves will not see nor ao challenged by operating conditions during that period.

In conclusion, granting this exemption request would postpone testing to maximize the use of limited resources during the current outage to improve the Millstone Unit No. 1 Appendix J program. This postponement would allow NNECO to avoid any additional radiation exposure and expense in testing a number of penetrations and valves more than once during this current outage. Primary containment integrity has not been required since the last LLRT and, consequently, the penetrations and containment isolation valves have not seen nor been challenged by operating conditions. Testing the penetrations and containment isolation valves more than once before containment integrity is required will not enhance protection of public health and safety.

3.0 EVALUATION The 2-year interval requirement for testing Type B and Type C components is intended to be frequent enough to prevent significant deterioration from occurring and long enough to permit the tests to be performed during the plant outages. Leak rate testing of the penetrations during plant shutdown is preferable because of the lower radiation exposures to plant personnel.

The underlying purpose of the requirement to perform Type B and Type C testing at intervals not to exceed 2 years is to protect the public by assuring that leakage through the primary reactor containment does not exceed allowable leakage rate values. The primary containment was designed to limit the off-site doses to values less than those specified in 10 CFR Part 100 in the event of a break in the primary system piping. Thus, containment integrity is required whenever the potential for loss of the primary reactor system integrity could result in significant offsite doses. Concern about such a condition exists whenever the reactor is critical and above atmospheric pressure. Tha licensee's facility is currently in an extended outage (i.e.,

the reactor is subtritical and at atmospheric pressure). During this outage, primary containment integrity is not required to be maintained. Primary containment integrity will not be requi ed until MNPSI restarts (currently U) ANSI /ANS-56.8 - 1987, " Containment System Leakage Testing Requirements."

cr> ANSI /ANS-56.8 - 1994, " Containment System Leakage Testing Requirements."

l!

scheduled for June 1998). 1herefore, the public will continue to be adequately protected from containment releases as long as MNPSI remains shut i

down.

The licensee will be required to perform the Type B and Ty)e C testing prior to restarting from the current refueling outage (RF015). Tierefore, l consistent with 10 CFR 50.12(a)(2)(ii), application of the regulations in this l particular circumstance would not serve, nor is it necessary to achieve, the underlying purpose of the rule. i 4.0 CONCLUSIOP On t'n e basis of i.he above discussion, the staff finds that the licensee's request for exem) tion is authorized by law, will not present an undue risk to the public healti and safety, ar.d is consistent with the common defense and security as specified in 50.12(a)(1). Additionally the proposed exemption meets the special circumstance given in 10 CFR 50.12(a)(2)(ii). Therefore, the staff has determined that the proposed exemption is acceptable, j Principal Contributor: S. Dembek Date: December 2, 1997 ,

l

+