ML20237H070
| ML20237H070 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 08/14/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20237H057 | List: |
| References | |
| NUDOCS 8709030106 | |
| Download: ML20237H070 (4) | |
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UNITED STATES 1
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NUCLEAR REGULATORY COMMISSION I
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SAFETY EVALUATION BY TH5 0FFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 8 TO FACILITY OPERATING LICENSE NO. DPR-21 NORTHEAST NUCLEAR ENERGY COMPANY MILLSTONE NUCLEAR POWER STATION, UNIT NO. 1 DOCKET NO. 50-245
1.0 INTRODUCTION
By letter dated Au0ust 11, 1987, Northeast Nuclea: Energy Company (NNECO) submitted a request for a change to the Millstone Nuclear Power Station, Unit No. I technical specification (TS) regarding control red drive (CRD) removal and repair or replacement.
The amendment revises the TS to allow removal and repair or replacement of a CRD with the reactor vessel head on, the cavity not flooded and the spent fuel pool [:ates in place (required by TS 3.5.F.7(a), (b) and (c)).
This amendment is consistent with the requirements for CRD removal in the TS prior to issuance of Amendment 1 on January 29, 1987.
By letter dated August 12, 1987, the staff issued a temporary waiver of compliance to NNEC0 which allowed CRD removal without meeting the requirements of Specifications 3.5.F.7(a), (b) and (c), provided that the ECCS systems required by 3.5.F.7(e) are operable with the 4160 volt supply breaker (s) racked in.
This waiver is effective until the license amendment is is. sued or until 5:00 p.m. DST August 17, 1987, whichever is earlier.
2.0 EVALUATION In its August 11, 1987, request to amend the operating license for Millstone Unit No. 1, NNECO proposed to revise the TS to reflect the intent of the restrictions placed on the removal and repair or' replacement of a single CRD while irradiated fuel is in the reactor vessel that were in effect prior to the issuance of Amendment No. 1.
In letters dated October 7 and 15, 1986, NNEC0 proposed to consolidate the then existing TS 3.5.F.7 (CRD removal) and 3.5.F.8. (fuel movement) into a new TS 3.5.F.7 to eliminate redundant wording contained in the two specifications.
In addition to the elimination of redundant wording, NNEC0 requested the addition of TS 3.5.F.7(a), (b) and (c) to impose addi+'ional restrictions for fuel movement during refueling.
- However, as rewritten, these additional restrictions in 3.5.F.7 applied not only to fuel movement, but also to CRD removal.
8709030106 870814 PDR ADOCK 0500024S P
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The proposed amendment reviscs TS 3.5.F.7 by adding paragraph (k), which states that "For purposes of control rod drive mechanism removal and/or replacement, specification 3.5.F.7(a),'(b) and (c) do not apply provided ECCS systems identified in 3.5.F.7(e) are operable with.the_4160 volt supply breaker (s) racked in."
i The staff has reviewed the request for amendment change and concludes that the proposed amendment is acceptable, i
3.0 EMERGENCY CIRCUMSTANCES On August 9, 1987, while performing the reactor vessel hydrostatic pressure l
test, NNECO determined that one CRD mechanism was leaking and required removal and repair or replacement.
However, Techhical Specification 3.5.F.7 requires that when irradiated f uel is in the reactor vessel and the reactor is in the refuel condition (as was the situation at Millstone Unit 1), a t
single control rod may be withdrawn and the drive mechanism replaced provided that, among other things, (a) the reactor vessel head is removed, (b) the cavity is flooded and (c) the spent fuel pool gates are removed.
Since Millstone Unit 1 was near the end of its refueling outage, none of these three conditions could be met without significant delay in the restart that was scheduled for August 13, 1987, i
NNEC0 also noted that power demand in New England was approaching a peak such that there were predicted power shortages during the rest of this summer.
Thus, there is an acute need for Millstone Unit No. 1 to return to power as soon as possible.
The staff concluded that the licensee's request for an emergency TS change was appropriate and because of the time required to process the emergency TS change, the staff issued a temporary r: W r of compliance, by letter dated August 12, 1987, which allowed CRD removal without meeting the, he U
requirements of specifications 3.5.F.7(a), (b) and (c), provided that t ECCS systems required by 3.5.F.7(e) are operable with the 4160 volt supply breaker (s) racked in, until the license amendment is issued or until l
5:00 p.m. DST August 17, 1987, whichever is earlier.
3.1 No Significant Hazards Consideration Determination The Commission's regulations in 10 CFR 50.92 states that the Commission may make a final determination that a license amendment j
involves no significant hazards consideration if operation of the t
facility in accordance with the amendment would not:
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(1)
Involve a significant increase in the probability or consequences of an accident previously evaluated; or I
(2) Create the possibility of a new or different kind of j
accident from any accident previously evaluated; or (3)
Involve a significant reduction in a margin of safety.
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-1 The information in Section 2.0 above provides the basis for evaluating 1
this license amendment against these criteria.
Since the requested operational mode is acceptable and the plant operating conditions, the physical status of the plant, and dose consequences of potential g
accidents are the same as without the requested change, the staff concludes that:
(1) The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
Significantly, the Millstone Unit No. 1 operating i
license, through the technical specifications in effect prior J
to issuance of Amendment 1 on January 29, 1987, allowed removal.
of a single CRD with the reactor vessel-head on, the cavity not i
flooded and the spent fuel pool gates in place.
Nevertheless, as summarized below, NNEC0 reviewed previously analyzed accidents and determined that the results are not affected.
Loss-of-Coolant Accidents - Should a leak develop during CR0 removal and replacement, core uncovery could occur sooner without the cavity flooded if no ECCS injection is available.
However, the proposed change ensures operability of adequate ECCS injection.
Therefore, there is no impact on core cooling regardless of whether.the cavity is flooded or not.
Criticality - This concern is independent of the proposed changes.
The potential of inadvertent criticality when a CRD mechanism is removed is independent of cavity flooding.
Therefore, there is no impact on the inadvertent critically event.
(2) The amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed amendment does not introduce any new failure modes and the plant response to previously analyzed accidents is not changed.
(3) The amendment does not involve a significant reduction in safety margin.
The amendment restores the original intent of TS 3.5.F.7 with respect to CR0 removal and repair or replacement.
Accordingly, we conclude that this amendment to Facility Operating License No. DPR-21, concerning removal of a single CR0 mechanism, involves no significant hazards consideration.
3.2 State Consultation In accordance with the Commission's regulations, consultation was held with the State of Connecticut by telephone.
The state expressed no concern either from the standpoint of safety or of no significant hazards determination, in view of the administrative nature of the amendment.
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4.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change to'a requirement with ge,spect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20.
The staff has determined that the amendment involves no significant increase in the amounts,'and no signi-I ficant change in the types, of any effluents that may be released offsite j
l and that there is no significant increase'in individual.or cumulative occupational radiation exposure.
Accordingly,'this amendment meets'the l
eligibility criteria for. categorical exclusion set forth in 10 CFR 51.22(c)(9).
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Pursuant to 10 CFR 51.22(b) no environmental impact. statement or environ-1 l
mental assessment need be prepared in connection with the issuance of this amendment.
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5.0 CONCLUSION
The staff-has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public j
will not be endangered by operation in the proposed manner, and (2).such activities will be conducted in compliance with the. Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
l Principal Contributor:
M. L. Boyle Dated:
August 14, 1987 k
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