ML20235L685
| ML20235L685 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 02/15/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20235L675 | List: |
| References | |
| NUDOCS 8902270628 | |
| Download: ML20235L685 (5) | |
Text
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"og UNITED STATES f+*9 NUCLEAR REGULATORY COlWMISSION o
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fg WASMiKiTON, D. C. 20555 A._./
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REALTOR REGtlLATION AflATED TO AMENDMENT N05,115 AhD 98 10 j
FACILITY OPERATIM LICENSE NOS. NPF-4 AN'O NPF-7 VIRGINIAELEgRICANLP0llERCOMPANY OLD DOMINION ELECTRIC COOPERATIVE RORTH ANi;A F0WER STATION, UNITS NO.1 AND 30, 2 D_0CKET N05. 50-338 AND 50-339
,1NTROMfTICE
'By htter dated January 13, 1989, the Virginia Electric and Power Company (the licensee) requested a change to the Technical Specifications (TS) for the North l
Anna Power Station, Units No. I and No. 2 (NA-1&2). The licensee requested that the p opocad change be treated as an exigent request in accordance with 10CFR50.91(a)(6).
The proposed amendments revise the NA-182 TS 3/4.9.10, Refueling Operations Vater Level - Reactor Yessel, to albu control rod movcment with the requirenant i
of 23 feet of water above the irradiated fuel assemblies,:ithin the reactor pressure vessel. This proposed change removes the ambiguity associated with control rod latching and unlatching operations where control rods are raised (with the upper icternals package installed) for weight or drag testing.
DISCUS 310N By letter dated May 23, 1988, the NRC issued License Amendments 102 and 89 for j
NA-182, rrTectively, which revised, in part, the applicability qf TS 3 9.10, Refuel?.ng Operations Water Level - Reactor Vessel. The specification requires 1
23 feet of water be mintained above the reactor pressure vessel flange during movement of fuel assemblies or control rods while in Mode 6.
These amendments were to have removed ; ambiguities associated with t he lowered water level during 3
movement of the upper internals package.
Based on subsequent conversations i
with the NRC, the licensee reviewed these amendments and concluded that further clarification was necessary.
As discussed in the NRC Safety Evaluation for License Artendants 102 and 39, the ainendments were to clarify that the refueling water leveh could be lowered in Order to install the upper internals lifting rig. By lowering the water level, l
contamination of the upper internals lif ting rig is prevented.
As the upper internals are remove 6/ installed, the refueling water level is adjusted to
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maintain shielding. At no time is the water level less than 23 feet above the j
irradiated fuel within the reactor vessel while the upper internals are removed.
The purpose of this prpposed TS change is to clari!fy that latching / unlatching of
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the control rods is part of the upper internals installation / removal process.
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During the in',tallation/ removal of the upper internels4 the control rod drive chafts must be latened/ unlatched to the r'od cluster control asce*1y. Tids operation is performed with the use of a pneumatic tool under water.
The unlatching operation must be performed before the upper internals are rsmcVed and hefore the lifting rig is in place. Tbc latching operation likewise must be (performed with the upper interr.als installed but af ter ths lifting rig has been removed.
in both.cp rations the refueling water levtl is i Wered to 23 feet above the top of the fuel within the reactor vessel to prevent contaminatMa of the lifting rig platform.
In both cases, the latching / unlatching operation is performed with the upper internals in place.
During t,oth latCning and unlatching operation $, the control rods are raised to test the connection between the control rod drive shtft and the rod.-cluster control assembly.. This proposed T5 change clarities that cor. trol r6d "mveent"
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within the reactor vessel with at least 23 feet of water at,ove the top of the irradiated fuell is acceptable.
The weight of the apper internals prevents movement of fuel asseMolies during this operation.
Therefors, the licensee wo9ld chrify the existing TS 3.9.10 l'y breaking it into two ports: TS 3.9.10.1 would address fuel asstrblies and assure that at least 23 feet of water wocid be maintained over the top of the reactor pressure vessel flange in Mode 6 during mcVement of fuel assenblies within containment._ References to control rod evolutions would be deleted. A new TS, 3.9.10.2, would be added to address control rod evoiations ir Mode 6 cnd require at least 23 feet of water be maintained w r the top of irradiated feel assemblies within the reactor pressure vessel. Tba is censistent with the existing basos for the specification.
As stated in the NA-162 TS bases, the restrictions on minimur water leve? ensure that sufficient water depth is available to remove 99% of the assumed 10% iodine j
gap activity released from the rupture of an irradiated fuel assembly. Tne l
minimum water depth iii consistent with the.asswetiens of the accident analysis.
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We have determined that the bases is technically unaffected by the proposed change in that the required minimum water levels are maintained throughout the upper internals installation /remeval prcress, including the control rod latching /
urlatching evolution described above.
However, to further clarify the specifi-cation, a partgraph would be added to the bases describing the minimum watar level for movement of fuel assemblies and control rods.
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FINDINGS The modification; to the NA-1&2 TS proposed by the licensee are judged by the NRC staff to be adequate and acceptable. The proposed change to the NA-1&2 TS has previously been upproved by the NRC for other facilities.
Fuel handling operations during refueling are unchanged end the refueling water level require-
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ment remains tonsistent with the accident analysis assumptions in the NA-1&2 l
Updated Final Safety Anulysis Report concerning the minimum required water level.
I Also, the margin of 10 CFR Port 100 dose limits is not reduced. Therefore, the NRC staff finds the proposed TS changes to be acceptable.
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EX1 GENT CIRCUMSTANCES I
L The Comission's regulations,10 CFR 50.91, centain provisions for issuance of Mfcudsente wier: the usual 304ty,nutlic nci, ice period cannot te met. One type of special etception is an exigency. An exiger.cy is a case where the str.ff and licensee need to act cromptly, but failure to act promptly does not involve a j
plant shutdown, derating, or delay in startup.
In the instant cese, plant startup could or could not be affected depending oa numerous factors which <ould affect refueling scheddes.
Also, ti.e edgency case usually represents an.
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amendment involvir.g a safety enhancement to the plant.
In the insta.nt case, the requested am:indment is an administrative clarification to the TS in support of scheduled reifueling operations.
l The forthcoming 1989 refueliag outane fcr NA-2, currently scheduie6 to commence February 10, 1989, is the first refueling outage which will be conducted under the revised fS 3.9.10.
The.licenree, in preparation for this refueling outage, determined in discussions with the NRC staff that the wording of the revised TS appeared to preclude the NA-1&2 refueling operations previously considved by the licen n e to be routine.
Current and forthcomir.g refueling procedures and equipmsnt design are based on this evolution.
Specifically, the wording could be interpreted to mean i. hat weight / drag testing of controls rods during unlatching / latching operations (i.e., movement) would require 23 feet of water above the reactor pressure vessel flange. As discussed abcVe, the licensee's interpretation is that these control rod unlatching / latching evolutions directly support ano are part of the reactor vessel upp:!r internals removal / installation evolutichs.
Until now, the licensee's normal refueling sequence has required the water level to be lowered to 23 feet above the top of the fuel assemblies within the reactor vessel for removal / installation of the upper internals package and maist 61ned at that level during control rod unlatching / latching.
Once the above concern on interpr9tation was identified, the licensee had-discussions with the NRC staff in the fourth quarter of 1983 to determine the appropriate mechanism for correctly interpreting or clarifying TS 349.10.
After ongoing discussions, the licensee submitted a letter to the NRC dated December 23,1988, recue2 ting concurrence with the licensee's interpretation of TS 3.9.10 discussed above.
On January 4,1989 the licensee was ii1 formed by the NRC staff that the appropriate rechanism for resolution would be to submit an appropriate TS change. By letter dated January 13, 1989 the licensee responded to the NRC with a proposed TS change as discussed above. Because the NRC guidance to submit a TS change was received on January 4,1989, and the NA-2 refueling cutage is r,cheduled to begin February 10,19P9, insufficient time remains to peimit the normal 20-day notice in the Federal Register.
Therefore, the licensee has requested that the change be processed in an exigent manner.
The licensee considered alternatives to the exigent request. These were changing procedure m.1/g equipment and rescheduling the NAo2 refueiing outage.
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1 Changing procedures and/or. equipment is not.a viable alternative since a soeci&1 tool would be requi! red for installation and removal of the upper internalc rig. Such a tool does not exist snd would have to be fabricated and tested and considerable delay could possibly impact restart. Finally, rescheduling the refueling outage to accommodate a 30-day period for the Federal lejLster Notice is not a viable option siince the NA-.2 refueling outage i
EuTLve tit 6 extended until at least the end of February 1989.
Based on all of the above, the Cocmission has determined that the licensee has not abused the exigency previsions of 10 CFR 50.91(a)(6)(vi). Failure of the Comission to act on the licensee request would result in a high probability of restart celay; and therefore the request should be processed under the exigency provisions of.10 CFR E0.91(a)(6)(viL FINAL NO SIGNIFICANT HAZARDS CONMDERATION DETERMINATION The Comission's regulations in 10 CFR 50.92 state that the Commission may make I
a final determination that a license amendment involves no significant hazards considerations if operation cf the facility in accordance with the amendment would not:
(1) involve a signiff. cant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant rseduction in a margin of safety.
The proposed change to Technical Specification 3/4.9.10 has been reviewed with respect to the criteria defined in 10 CFR 50.92.
The proposed change will not:
(1) involve an ibcrease in the probability or consequences of an accident i
previously evaluated. This change does not alter the conditions or J
assumptions of the accident analysis or the basis of the current TS.
Fuel handling operations during refueling are unchanged and the refueling water level requirement remains consistent with the accident analysis assumptions in the UFSAR concerning the minimum required water level. Therefore, the probability and the consequences of tne fuel handling accident are not inc-sed.
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(ii) create the possibility of a new or different kind of accident from any accident previously identified. This change does not. alter the conditions or assumptions of the accident analysis or the basis of the current TS.
Fuel handling operations during refueling are unchanged, and therefore, the fuel handling accident evaluated in the UFSAR remains bounding in terms of the type of accidents that may occur and a new and Ciifferent kind of accident is not created.
(iii) involve a reduction in a margin of safety. This change does not alter the conditions or assumptions of the accident analysis or the basis I
of the current TS.
Fuel handling operations during refueling are unchanged and the refueling water level requirement remains consistent with the assumptions of the accident analysis.
Consequently, the margin of 10 CFR Part 100 dose limits is not reduced.
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Based upon' the.above considerations; the staff concludes that the ' amendment meets j
the three criteria of 10 CFR 50.92. Therefore, the staff has made'a final:
determination that the proposed amendments do not involve a significant hazards y
consideration.
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ENVIRONMENTAL CONSIDERAT10N
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These amendments involve' a change in the installation or use-of. a? facility-1 ti -
component located within the restricted area as defined in 10 CFR Part 20 and j
]T changes to surveillance : requirements. The staff has determined that the amend-ments involve no significant increase in the amounts, and no significant change f' I.
in the types, of ary effluents that may;be released offsite,-and that there is l
no significant increase in individual or cumulative occupational' radiation-
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exposure. The Conunission has previously ' published a proposed finding that' the y
4 amendments' involve no significant hazards consideration and there has been no
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, public coninent on such finding. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 951.22(c)(9).' Pursuant -
l to 10 CFR 651.22(b), no environmental-impact statement or environmental assessment i
need be prepared in connection with the'1:ssuance of the amendments.
dp CONCLUSION We.h' ave concluded, based on the considerations discussed above, that (1) because the amendments do. not involve-a.signif fr. tnt increase in the probability or -
consequences of' an accident prev'iously evaluated, do not create the possibility of an accident:of a type different from any evaluated previously, and do'not l
' involve a significant reduction sin a margin of safety, the amendments do not involve a significant hazards consideration, (2) there is reasonable assurance that the-health and safety of the public will not be endungsied by operation in the proposed manner, and (3) such activities will be conducted in conpliance with the Counission's regulations, and the issuance of the amendrents will not be
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inimical to the common defense and security or to the health ard safety of the 1
public.
Date:
February 15, 1989 Principal Contributor:
Leon Engle 1
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