ML20083A128
| ML20083A128 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 05/02/1995 |
| From: | Horn G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20083A131 | List: |
| References | |
| NLS950075, NUDOCS 9505100050 | |
| Download: ML20083A128 (8) | |
Text
{{#Wiki_filter:r ? a J GENERAL OFFICE g P O. box 499. COLUMBUS. NEBRASKA 686024499 Nebraska Public Power District TAxiMSF GUY R. HORN Vice-President. Nuclear (402) 563-5518 NLS950075 May 2,1995 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555
Subject:
Proposed Change No.156 to Technical Specifications Surveillance Interval Extension; Drywell Head and Manport Cooper Nuclear Station NRC Docket No. 50-298, DPR-46
Reference:
Letter (No. NLS940133) to the U.S. NRC Docmnent Control Desk from Nebraska Public Power District dated December 27,1994;
Subject:
Exemption Request - 10 CFR 50 Appendix J, Paragraph III.D.2(a) Gentlemen: In accordance with the applicable provisions specified in 10 CFR 50, the Nebraska Public Power District (District) requests that the Cooper Nuclear Station (CNS) Technical Specifications be revised as specified in the attachment. This proposed change temporarily revises Surveillance Requirement (SR) 4.7.A.2.f.1 to extend the two year Local Leak Rate Test (LLRT) interval requirement, as it pertains to both the Drywell Head and Manport, from the current due date of July 17, 1995, to the completion of refueling outage (RE-16), currently scheduled to commence October 1995. Because the two year LLRT interval is a requirement of 10 CFR 50 Appendix J, a one-time schedular exemption request has been submitted per the above reference. In order to avoid a plant shutdown to perform this testing, the District requests Nuclear Regulatory Commission (NRC) approval of the referenced exemption request and the subject pioposed change prior to July 17,1995. The atteuco contacas a description of the proposed change, the attendant 10 CFR 50.92 evaluation, and the CNS applicable Technical Specification page in both fimal and marked up forms. This proposed change has been reviewed by the necessary District safety review committees and incorporates all amendments to the CNS Facility Operating License through Amendment 168, issued February 3,1995. By copy of this letter and attachment, the appropriate State of Nebraska official is being notified in accordance with 10 CFR 50.91(b)(1). Copies to the NRC Region IV Office and the CNS Resident inspector are also being sent in accordance with 10 CFR 50.4(b)(2). / v/jf / 9505100050 950502 PDR ADDCK 05000298 P PDR L yl U$$bkhk kW$$0N$$$N$$0$U$$$ $.N [W c =
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- May 2,~ 1995
+ -:. ;. ? Page 2 of 3 '{ If yoh have any questions or require any additional information, please contact ~ 7 - me. ' Sincerely,' 0~ orn v. . Vi resident - Nuclear .GRH/ dam 1-Attachment cc: H. R. Borchert Department of Health State of Nebraska Regional Administrator USNRC Region IV Arlington, TX NRC Resident Inspector Cooper Nuclear Station NPG Distribution L. L'. l l l' _ _ _ _____ _ _____ _ ___.________.____ _ ___ _ ____._i____ _.____ _ ____
3 l 'U.S. Nuclear Regulatory Commission May 2,1995 Page 3 of 3 STATE OF NEBRASKA) )ss PLATTE COUNTY ) G. R. Horn, being first duly sworn, deposes and says that he is an authorized representative of the Nebraska Public Power District, a public corporation and political subdivision of the State of Nebraska; that he is duly authorized to submit this request on behalf of Nebraska Public Power District; and that the statements contained herein are true to the best of his knowle ge and belief. (viu ln_ orn Vice-President, Nuclear Subscribed in my presence and sworn to before me this Mrd day of h , 1995. J OEE NOTARY PUBLIC I
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' Attachment ' to. 7 h., ? NLS950075 j Page.1; of 5'- l l REVISED TECHNICAL SPECIFICATIONS y ~ Proposed Change No.156 4 Surveillance Interval Extension Drywell Head and Manport ' Revised Panes 162 L INTRODUCTION ) The Nebraska Public Power District (District) requests that the Nuclear Regulatory. Commission (NRC) approve Proposed Change No.156 to the Cooper Nuclear Station. (CNS) Technical. Specifications described'below. The proposed change temporarily. revises Surveillance Requirement (SR) 4.7.A.2.f.1 in order to extend the.two year TypeL r: . B Local Leak Rate Test (LLRT) interval requirement for both the Drywell. Head and' Manport (Penetrations DWH and X-4 respectively) until the. completion of Refueling 1 Outage No.16 (RE-16), currently scheduled to commence October 1995. Because the. two year interval is a requirement of 10 CFR 50 Appendix J, an exemption'is also r i required to support the Technical Specification change. The District' submitted a one-- l time' schedular exemption request on December 27, 1994L'. ' Both the schedular- -j exemption and Proposed Change _ No.156 require. Nuclear Regulatory Commission-l (NRC) approval prior to July 17,1995, which is the current due date for the Type B - j LLRT on Penetrations DWH and X-42'. j iii II.- BACKGROUND j l Cooper Nuclear Station (CNS) Technical Specification Surveillance Requirement (SR) 4.7.A.2.f.1 requires that Local Leak Rate Tests' (LLRTs) be pbrformed on the primary containment testable penetrations and isolation valves during each reactor shutdown for j refueling, or during other convenient intervals, but in no case at intervals gr. eater than'
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Letter (No. NLS940133) to the U.S. NRC Document Control Desk from Nebraska ~ -l ~ Public Power District dated December 27,1994i
Subject:
Exemption Request - 10 CFR' y 50 Appendix J, Paragraph III.D.2(a) j j - 2/ .The letter referenced in Footnote 1/ inappropriately referred to the Drywell. Head and 1 Manport as Penetration X-4 when, in reality, they ~ represent two ' penstrations ] (Penetration DWH and X-4) which are closely related. Both Penetrations are Type B j tested at about the same time, with the last tests having been performed July 17,1993. j The bases supporting the exemption request referenced in Footnote 1/ is unaffected by the clarification that the Drywell Head and Manport constitutes two penetrations. a i 5
s T f. LAttachment to- 'in /e NLS950075 a . Page 2 0f 5. g B ' two years. However, CNS has, experienced 'a longer than expected 1993 refueling-outage (March 5 through-August 1,~ 1993), coupled with the more recent unplanned outage (May 25, 1994 through February 21,~ 1995).: zThese factors, along.'with; the . anticipated load demand and fuel capacity, have resulted in the rescheduling of the next refueling outage to October 1995. ~ During the May' 25,1994 - February 21,1995 unplanned outage, the District evaluated. < the schedule for performing the required Type B and C tests to ensure that all of these " tests are performed within the Technical Specification and 10 CFR 50 Appendix J two . year - maximum : surveillance interval. As a result of this evaluation,. the. District determined that only two.LLRTs will come due when anticipated plant conditions will: prohibit performance.of the test. These'are the Type B LLRTs required for.both.the.. c Drywell Head and_ Manport (Penetrations!DWH and X respectively),1 which are
- currently due July 17, 1995.'- CNS anticipates being at reactor po_wer operation during.
July 1995. During reactor power operation, the extreme radiation environment prohibits personnel from ' performing the subject LLRTs or any of the activities (removal. and replacement of the shield blocks on the refueling floor) associated.with these tests. The ; subject LLRTs are normally performed during refueling outages. For' the above. reasons, the District proposes that the two year Type B LLRT interval requirement for Penetrations DWH and X-4 be extended to coincide with RE-16.' Because the two year interval is a requirement of 10 CFR 50 Appendix J, Section III.D.2(a), the District submitted a one-time schedular exemption request December 27,1994, (referenced on Page 1 of this attachment). The District requests NRC approval of Proposed Change. 156 along with approval-of the exemption request no later than July 17, 1995. Otherwise,:CNS will be forced to shutdown solely for the purpose of performing.the - subject tests. As demonstrated in the referenced exemption request and the following 10 CFR 50.92 evaluation, the District has concluded that an extension of the two year test interval by approximately six months for Penetrations DWH and X-4 will not present an undue risk to the public health and safety. This conclusion is based on the fact that-these penetrations have not failed an LLRT in the last 19 yearsl'. This surveillance history _- demonstrates that these penetrations are not subject to leak related failures. Additionally, the drywell head seal is made from a 45 ' 5 durometerf silicone rubber 1/. The letter referenced in Footnote 1/ stated that the Drywell Head had never failed an as-found LLRT. In 1975, Penetration DWH was found to be leaking in excess of the arbitrary administrative limit established in CNS Operations Procedure 6.3.1.1. However, the leakage recorded,. 0.41 standard cubic feet per hour, provided an insignificant contribution to the Technical Specification limit of 0.60 La and was not indicative of a seal or penetration failure. 4/ The letter referenced in Footnote 1/ identified this value as "+45 to -5 durometer" which is a typographical error. The correct value is "4515 durometer".
~ ' S. Attachment"to v ~ NLS950075-Page 3 of 5 ) compound.- While environmental conditions such as - heat and radiationH cause degradation in silicone compounds, it is reasonable to conclude that less degradation can be expected 'due to the extended shutdown and subsequent lower temperature' and. radiation levels experienced by the seals. The Drywell Head and Manport penetrations ~ le 'are not active components, and therefore, are not subject to active' failure criteria.- II.' DESCRIPTION OF CHANGES The change to the CNS Technical Specifications consist of adding a footnote'to SR 4.7.A.2.f.1 in order to provide a one-time extension of the two ' year test interval. required for Type B local leak rate testing on Penetrations DWH and-X-4 (Drywell-Head and Manport respectively). The footno*e allows these tests to'be performed during the next refueling outage (RE-16),' curr:ntly scheduled for October 1995, as opposed to the current date of July 17,1995. ~ The appendix to this submittal contains both the marked-up and revised: Technical. Specification page affected by this proposed change. The District-requests NRC - approval of this proposed change along with the referenced exemption request prior to - July 17,1995. Otherwise, CNS will be forced to shutdown solely for the purpose of performing the subject tests. Due to the nature of Proposed Change No.156, the District requests that this change become effective immediately upon approval. III. SIGNIFICANT HAZARDS DETERMINATION 10 CFR 50.91(a)(1) requires that licensee requests for operating license amendments be accompanied by an evaluation of significant hazards posed by the-issuance of the amendment. This evaluation is to be performed with respect to the criteria given in 10 CFR 50.92(c). The following analysis meets these requirements. Evaluation of this Amendment with Respect TO 10 CFR 50.92-The enclosed Technical Specifications change is judged to involve no significant
- hazards based on the following:
1. Does the proposed change involve a significant increase in the probability or : consequences of an accident previotisly evaluated? ' Evaluation This license amendment request revises Surveillance Requirement (SR) 4.7.A.2.f.1 to allow the one-time schedular extension of the two year Type B Local Leak Rate Test (LLRT) interval required for the Drywell Head and Manport (Penetrations DWH and X-4 respectively). This extension will allow Penetrations DWH and X-4 to be Type B tested during Refueling Outage No.
n e W- ' Attachment. to? [ve
- NLS950075 '
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_16 (RE-16), which1is ' currently scheduled ? to commence" October 1995. p " Currently, the two year maximum interval for these penetrations comes:duc July 17,.1995.L The District has concluded that a one-time extension of ~ approximatelyJsix months' beyond. the two year limit will. not result 'in a significant increase in the probWlity of these; penetrations failing to perform - L their. safety function. This conslusion-is. based i on the previous i LLRT surveillance history of Penetrations DWH and X-4, which have not failed lan LLRT in the last 19 years.:1 The surveillance. history demonstrates that these'. - penetrations are not subject to leak related failures.- m Additionally, the seals associated with these~ penetrations will.'not have ' experienced significantly more radiation and heat exposure by the conclusion of the proposed' extension than they.would have during; the current;two year u interval. ' Although some radiation and heat is present during plant shutdowns,- the seal degradation resulting from these conditions 'is significantly slower. Because seal degradation is a function of heat and radiation, and is generally not = a function of time, the District has concluded that the one-time extension will not result in a significant increase of seal degradation. Because seal failure for these penetrations is largely based on the rate of seal degradation, the probability y of the failure of these penetrations'is not significantly increased. Therefore, a significant increase in the probability or consequences..of an accident is not created. This proposed change does not introduce any new modes.of plant operation, make any physical changes, or alter any operational setpoints. - The change does - not degrade the performance of any safety system assumed to function in'the - accident analysis. Therefore, this proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated. 2. Does the proposed change create the possibility for a new or different kind of accident from any accident previously evaluated? Evaluation This license amendment request involves the one-time schedular extension of the LLRT interval requirement for Penetrations DWH'and X-4. SR 4.7.A.2.f.1 is being revised to extend the surveillance test interval for Penetrations DWH and' X-4 to coincide with RE-16, currently scheduled to commence October 1995. A one-time extension of the subject surveillance interval does not involve the creation, deletion, or modification of the function of any structure, system, or component, nor does this change introduce or change any mode of plant operation. This proposed change does not create the possibility for a new or different kind of accident from any accident previously evaluated.
Pi. n dr- ' Attachment 'to .NLS950075 ?' +- Page.5 of 5: /3. 'Does the proposed change create a significant. reduction in the margin 'of safety?.
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. Evaluation This license amendment request involves the one-time _ extension of the two year. maximum surveillance test interval for Penetrations DWH and X-4 from the : s: current due date of July 17,'1995, to instead coincide, with' RE-16, which'is. scheduled to commence October,1995.: By the time these tests are performed,1 1. Lthe penetratioa seals will not have experienced significantly more radiation and j ' heat than they would have during the previous test intervals. Therefore,~ the i ~ penetration seals will not have experienced significant degradation as a result of. the extended interval.' Furthermore, Penetrations DWH and X-4 have not failed an LLRT in the last 19 years. The surveillance history demonstrates that these penetrations are not subject to leak related failure. This proposed change 'does. 'l not involve any change. to plant design, equipment instrument-setpoints,' or. operation. Therefore,. this proposed change does not' create L a' significant reduction in the margin'of safety.' q ' IV.' CONCLUSION' The. District has evaluated the proposed change described above against the criteria j given in 10 CFR 50.92(c) in accordance with the requirements of 10 CFR 50.91(a)(1).' This~ evaluation has determined that this proposed change will apt 1) involve a significant increase in the_ probability or consequences.of an ~ accident. previously evaluated, 2) create the possibility for a new or different kind of accident from any accident previously evaluated, or 3) create a significant reduction in the margin of a of Proposed Change No.156. j safety. Therefore, for the reasons detailed above, the District requests NRC approval-l l 'i -{ e f -i P ~t i ,}}