ML20141L882

Safety Evaluation Supporting Amend 101 to License DPR-21

ML20141L882
Person / Time
Site:	Millstone
Issue date:	05/28/1997
From:	NRC (Affiliation Not Assigned)
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ML20141L878	List: ML20141L876 ML20141L879 ML20141L882
References
NUDOCS 9706030092
Download: ML20141L882 (5)

Text

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. a UNITED STATES j Ow) e S NUCLEAR REGULATORY COMMISSION

@/ ..,g f WASHINGTON, D.C. 00565-0001 SAFETY EyalHATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.101 i TO FACILITY OPERATING LICENSE NO. DPR-21 NORTHEAST NUCLEAR ENERGY COMPANY MILLSTONE NUCLEAR POWER STATION. UNIT 1 4

DOCKET NO. 50-245 i

1.0 INTRODUCTION

l By letter dated March 6, 1997, the Northeast Nuclear Energy Company (the 4

licensee) submitted a request for changes to the Millstone Nuclear Power Station, Unit 1 Technical Specifications (TS). The requested changes would revise the TS for (1) allowable outage times (A0T) for specified protective

instrumentation, and (2) reactor building access control.

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2.0 BACKGROUND

A licensee self-assessment determined that performance of certain 4

surveillances would result in short periods when protective instrumentation is inoperable and the TS require tripping of the initiation logic associated with

! the instrumentation to be tested. To correct this TS wording weakness, the licensee proposed changes to its TS using the NRC guidance provided in Standard TS, NUREG-0123, " Standard Technical Specifications for General Electric Boiling Water Reactors (BWR/5)," Revision 3 (NUREG-0123) and improved Standard TS, NUREG-1433, " Standard Technical Specifications General Electric Plants BWR/4," Revision 1 (NUREG-1433).

i Additionally, other testing and maintenance may result in the secondary d

containment not being in compliance with the TS. The Containment Systems

, Limiting Condition for Operation (LCO) does not specify an A0T for restoration i of secondary containment. Also, no surveillance requirement exists to

, periodically confirm that at least one door in each of the double-doored

accesses to the secondary containment is closed.

The licensee's proposed amendment is designed to eliminate the above 4

identified weaknesses by adopting appropriate guidelines pertaining to protective instrumentation from NUREG-0123 and NUREG-1433, and reactor i

building access control from NUREG-1433.

3.0 EVALUATION 3.1 Instrumentation Allowable Outage Times i The licensee is proposing to insert "A channel may be placed in an inoperable

, status for up to two hours during periods of required surveillance without placing the Trip System in the tripped condition provided the associated Trip 9706030092 970528 l PDR ADOCK 05000245 P PDR .

i Function [or function) maintains trip capability. Otherwise, ..." in Note 1 of Table 3.1.1, " Reactor Protection System (SCRAM) Instrumentation Requirements;" Table 3.2.1, " Instrumentation that Initiates Primary Containment Isolation Functions;" Table 3.2.2, " Instrumentation that Initiates and Controls the Emergency Core Cooling Systems;" and Table 3.2.3,

" Instrumentation that Initiates Rod Block." This TS change will allow the licensee to perform surveillance tests without placing the applicable trip system in the trtpped condition.

The licensee's current TS are nonstandard and contain weaknesses that were addressed by the staff in the standardized TS (e.g., NUREG-0123 and NUREG-1433). The licensee plans to more completely address these weaknesses in the future by fully converting to the TS recommended in NUREG-1433.

However, the licensee does not plan on submitting this request until 1998. In this case, literal corpliance with the current TS wording would cause the licensee to place protective instrumentation undergoing a surveillance in the tripped condition. However, an instrument in a tripped condition cannot be fully tested. Also, placing the instrument in a tripped condition during a surveillance increases the chance of spurious plant transients (since a false trip signal on the remaining channel will cause a safety system initiation).

The staff determined that the licensee's proposed TS wording is consistent with the applicable portions of NUREG-0123 and is therefore acceptable. The staff also notes that its subsequent guidance (i.e., NUREG-1433) allows a 6-hour time period for conducting these types of surveillances.

Additionally, the licensee is proposing to insert "One air ejector off-gas system radiation monitor may be placed in an inoperable status for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> during periods of required surveillance without placing the Trip System in the tripped condition. Otherwise, from..." in TS 3.2.D.2. The basis for this change is the same as that for the change discussed above.

However, for the instrumentation discussed above, NUREG-0123 recommends a 2-hour A0T for conducting the surveillances and the licensee is requesting a 2-hour A0T. In this case, as noted by the licensee, NUREG-0123 recommends a 1-hour A0T. The licensee provided the following justification for a 2-hour A0T for this instrument:

These radiation monitors are arranged in a two-out-of-two logic; therefore, both must trip to initiate the required action (closure of the off-gas isolation valve to the main stack). This action, however, is automatically delayed by 15 minutes. A high radiation condition sensed by the monitor in service would provide sufficient time to take corrective actions. Since a two-hour A0T is deemed acceptable for instrumentation in systems such as the Reactor Protection System and Emergency Core Cooling System, it is appropriate to apply a two-hour A0T to these radiation monitors.

The licensee also stated that:

Additionally, the NUREG-0123 A0T of one hour does not allow sufficient time to perform required surveillance testing without placing undue stress on the test performer.

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l' The staff reviewed the licensee's proposal and agrees that due to the >

15-minute actuation delay, the plant operators will have adequate time to take j

the appropriate action if a real actuation signal occurs. Also, testing the 15-minute actuation delay would by itself take up a significant portion of the 1-hour test period recommended in NUREG-0123. Additionally, the 2-hour period is consistent with the testing period allowed for the other instrumentation A0Ts in the licensee's request. Therefore, the licensee's proposal to deviate from the recommendation in NUREG-0123 and instead allow a 2-hour period to l conduct the surveillance test is acceptable. '

The licensee also proposed to substitute "shall" for "may" in existing Note 1

of TS Table 3.2.2. Currently, the note reads "If the first column cannot be 1 met for one of the trip systems, that system may be tripped." The use of the

, word "shall" instead of "may" makes it clear _to the operators that this action t

is a requirement and not an option. Therefore, the licensee's proposed wording revision for Note 1 of TS Table 3.2.2 is an acceptable TS clarification.

4 Additionally, the licensee made changes to the TS Bases to reflect the above

TS changes.

3.2 Secondary Containment Integrity

The licensee is proposing to change the required corrective action if the TS's containment integrity requirements cannot be met. Specifically, paragraph j 3.7.C.2. will be changed as follows:

Current wording:

If the above [i.e., the 3.7.C.1 operability requirements] cannot j be met, immediately suspend the activities listed in 3.7.C.I.a and 3.7.C.1.b and establish, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, conditions where secondary containment integrity is not required [e.g., cold l shutdown].

Proposed wording:

} If the above [again, the 3.7.C.1 operability requirements] cannot l be met:

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, a. immediately suspend the activities listed in 3.7.C.I.a and 3.7.C l.b; and 1

l b. when in RUN, STARTUP/H0T STANDBY, or H0T SHUTDOWN, restore i secondary containment to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or establish, within the succeeding 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, conditions where secondary containment integrity is not required (e.g., cold shutdown].

i The licensee's proposed wording clarification is consistent with the intent of the current wording with the exception that the licensee's proposal would add a 4-hour time period to allow plant operators to restore secondary containment to operable status if it is found inoperable while the plant is in run, 4

4

s startup/ hot standby, or hot shutdown. Although the licensee's proposed i 4

wording differs from the current TS, the licensee's proposal is consistent ,

with the staff's applicable TS wording in NUREG-1433. The NUREG-1433 l justification for this 4-hour time period is-  !

~

The 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Completion Time provides for a period of time to correct the problem that is commensurate with the importance of maintaining secondary containment during [run, startup/ hot standby, or hot shutdown). This time period also ensures that the probability of an accident (requiring secondary containment operability) occurring during periods where secondary containment is inoperable is minimal.

Since the licensee's proposed wording is consistent with the NUREG-1433 guidance, it is acceptable.

The licensee also proposed to add a new secondary containment . surveillance

requirement, that would read:

b. At least once a month, verify at least one door in each j secondary containment access opening is closed.

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This proposed surveillance requirement is a new requirement that would help ensure that infiltration of outside air of such a magnitude as to prevent

maintaining the desired negative pressure does not occur. The licensee's I j proposed surveillance requirement wording is less restrictive than the staff's recommending wording in NUREG-1433 which requires, in part, that "all" i secondary containment equipment hatches and access doors be verified closed.

However, the licensee's proposal is acceptable because: (1) it is consistent with the current plant design basis as noted in the TS definition of secondary

containment integrity (which states, in part, "At least one door in each access opening is closed."), and (2) it is a conservative improvement over the

current TS surveillance requirement which only requires a test once per operating cycle and prior to fuel movement (the licensee's proposed monthly testing frequency is consistent with the 31-day testing frequency recommended in NUREG-1433).

Additionally, the licensee made changes to the TS Bases to reflect the above TS changes.

4.0 STATE CONSULTATION

. In accordance with the Commission's regulations, the Connecticut State official was notified of the proposed issuance of the amendment. The State official had no comments.

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5.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. The NRC staff has determined

i. that the amendment involves no significant increase in the amounts, and no l significant change in the types, of any effluents that may be released

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l offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a i

proposed finding that the amendment involves no significant hazards i consideration, and there has been no public comment on such finding (62 FR 14462 dated March 26,1997). Accordingly, the amendment meets the l eligibility criteria for categorical exclusion set forth in 10 CFR '

51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or

environmental assessment need be prepared in connection with the issuance of i the amendment.

6.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: S. Dembek Date: May 28, 1997

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