ML20197J586

Application for Amend to License NPF-3,revising TS Surveillance Requirements for ISI Requirements of Internal Auxiliary Feedwater Header,Header to Shroud Attachment Welds & External Header Thermal Sleeves

ML20197J586
Person / Time
Site:	Davis Besse
Issue date:	12/23/1997
From:	Jeffery Wood CENTERIOR ENERGY
To:
Shared Package
ML20197J579	List: ML20197J576 ML20197J586 ML20197J597
References
NUDOCS 9801050031
Download: ML20197J586 (9)

Text

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Docket Number 30 346 License Number NPF-3 SerialNumber 2471 3'

Eiiclosure PageI r

i APPLICATION FOR AMENDMENT i

TO FACILITY OPERATING LICENSE NUMBER NPF-3

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DAVIS BESSE NUCLEAR POWER STATION UNIT NUMBER 1 Attached are the requested changes to the Davis Besse Nuclear Power Station, Unit Number 1 Facility Operating License Number NPF 3. Also included is the Safety Assessment and Significant flazard. C isideration.

The proposed changes (submitted under cover letter Serial Number 2471) concern:

Appendix A, Technical Specifications (TS):

f 3/4.4.5 Reactor Coolant System - Steam Generators By:

(

J.K. good Vice President -huclear Sworn to and subscribed before me this 23rd day of December, )997 ArW)

Notary Public, State of Ohio L.AUltA A ANN 15 w c -,,% s. 0N e

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Docket Number 50 346 License Number NPF 3 SerialNumber 2471

- Enclosure Paf;c 2 The following information is provided to support issuance of the requested changes to the Davis-liesse Nuclear Power Station (DIINPS), Unit Number 1, Facility Operating License Number NPP 3, Appendix A, Technical Specifications. The change involves Technical Specification (TS) 3/4.4.5, Reactor Coolant System - Steam Generators.

A.

Time Required to implement: This change is m be implemented within 90 days after the NRC issuance of the License Amendment.

11.

Reason for Change (License Amendment Request Number 95-0015) :

This application proposes to revise the TS Surveillance Requirement (SR) 4.4.5.8 to state:

"These inspections of the secured internal auxiliary feedwater header, header to shroud attachment welds, and external header thermal sleeves shall be perfonned during the third period of each ten ycar Inservice Inspection Interval (ISI)." The present SR wording specifies that the visual inspections be performed "at the ten year 1S1."

This change is proposed considering the guidance of Section XI of the ASME Iloiler and Pressure Vessel Code. Article IWC 2412 divides the inservice inspection interval into three inspection periods. Article IWC-2420(a) requires that the sequence of component examinations established in the first inspection interval be repeated during each inspection interval to the extent practical. The required visual inspections were perfonned during the third and fourth refueling outages, and during the Sixth Refueling Outage, which occurred during the third period of the first ISI. Under current TS wording, the visual inspections of the internal auxiliary feedwater header, header to shroud attachment welds, and external header thermal sleeves must be performed during the second ten year Inservice inspection which occurs in 12 RFO. This proposed change will allow the visual inspection to be performed any time within the third period of the second ISI interval (See attached Figure). The visual inspection will be performed again in the third period cf the third and fourth ten year ISI intervals.

C.

Safety Assessment and Significant llazards Consideration: See Attachment

i Docket Number 50 346

- License Number NPF 3 SerialNumber 2471 i

Aitachment I

i SAFETY ASSESSMENT AND SIGNIFICANT HAZARDS CONSIDERATION FOR LICENSE AMENDMENT REQUEST NO. 95-0015 (18 pages follow) j E'

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LAR 95 0015 Page 1 SAFETY ASSESShiENT AND SIGNIFICANTliAZARDS CONSIDERATION FOR LICENSB AhiENDhiENT REQUEST NUMBER 95-0015 TITLE:

Proposed Revision of Technical Specification (TS) 3/4.4.5, Reactor Coolant System. Steam Generators, Surveillance Requirement (SR) 4.4.5.8, Visual Inspection of the Secured Internal Auxiliary Feedwater llender, licader to Shroud Attachment Welds, and External lieader Thermal Sleeves DESCRilrrlON:

The purpose of the proposw change is to modify the Davis Besse Nuclear Power Station (DBNPS), Unit Number 1, Operating License NPF-3, Appendix A Technical Specifications.

This License Amendment Request (LAR) proposes that TS 3/4.4.5, Reactor Coolant System -

Steam Generators, Surveillance Requirement (SR) 4.4.5.8 (see attached marked-up Technical Specifications) be revised to state: "These inspections of the seceted internal auxiliary feedwater header, header to shroud attachment welds, and the external header thermal sleeves shall be perfonned during the third period of each ten year Inservice Inspection (ISI) Interval." The present SR wording specifies that the visual insiv :tions be performed during the third and fourth refueling outages and "at the ten year ISI."

This proposed change will allow the visual inspection to be performed anytime within the third period of the second ISIinterval, thus allowing added flexibility in scheduling the perfonnance of the inspections. Refer to the attached figure for a depiction of the Inservice Inspection timeline under the proposed SR change. Under the proposed change, the required visual inspections will be performed again in the third period of the third and fourth ten-year ISI intervals.

Also, the proposed change deletes the surveillance requirement reference to the third and fourth refueling outages. These requirements were completed and are no longer applicable.

SYSTEMS. COMPONENTS. AND ACTIVITIES AFFECTED:

Designated time for visual inspection of the secured internal auxiliary feedwater header, header to shroud attachment welds, and the external header thennal sleeves.

FUNCTIONS OFTilE AFFECTED SYSTEMS. COMPONENTS AND ACTIVITIES:

The original DBNPS Auxiliary Feedwater (AFW) design included torus shaped headers positioned inside both steam generators at the upper end of the upper vertical cylindrical baffic.

During the 2RFO (April,1982), Toledo Edison discovered that the AFW header in each steam generator had become partially dislodged and severely deformed. This event was reported to the

- NRC as Licensee Event Report (LER)82-019. It was determined that the original design of the

LAR 954)015 Page 2 hehder was faulty. A new design, providing auxiliary feedwater distribution via an external header arrangement was later installed to perfonn the function of the internal header. The damaged internal headers were stabilized in place with welds and gunet plates, rather than being removed, because the construction features of the steam generator made their removal extremely difficult. The NRC issued a Srtfety Evaluation Report (SER) which accepted these modifica-tions in August,1982 (TE lag Number 1064).

The function of the visualinspection of the secured internal auxiliary feedwater header, the header to shroud attachment welds, and the external header ther, ial sleeves is to confinn that no deterioration of the header stmetural welds or attachment welds has occurred and that the thennal sleeves have not developed cracks. These inspections were established to ensure that there are no new failure mechanisms resulting from these components. The requirement to perfonn these inspections was added by Amendment Number 62 to the DBNPS Operating License Technical Specifications.

There are no hardware modifications associated with the proposed TS changes.

EFFECTS ON SAFETY:

The proposed revision c,f TS SR 4.4.5.8 would allow the visual inspection of the secured internal auxiliary feedwater header, heeder to shroud attachment welds, and external header thennal sleeves to be perfonned during any refueling outage that falls in the third period of the ten year inservice inspection interval (see attached figure). Under the current TS SR 4.4.5.8, the visual inspections in both Steam Generators must be completed during the refueling outage at the ten -

year ISI, which is normally defined as the outage when the reactor is disassembled for the examination of the reactor vessel welds. The next such outage at the DBNPS will be the 12RFO, scheduled for the yea: 2000.

The NRC SER for Amendment Number 62 (TE Log Number 1376 dated September 30,1983) stated that inservice inspections would be perfonned during each ten year Inservice inspection interval to confirm that no deterioration had occurred. Although the visual inspections of the secured internal auxiliary feedwater header, header to shroud attachment welds, and the external header thermal sleeves are not Code examinations,Section XI of the American Society of Mechanical Engineers (ASME) Boller and Pressure Vessel Code can be consulted for scheduling guidance for SR 4.4.5.8 since its performance is tied by TS to the Inservice Inspection interval.

Anicle IWC-2412, inspection Program B, divides the ten year Inservice inspection interval into three inspection periods. Article IWC 2420(a), Successive inspections, requires that the sequence of component examinations established in the first 10-year inspection interval be repeated during each subsequent ten year inspection interval to the extent practical.

Since the visual inspection of these components was perfonned during the third period of the first ten year Inservice Inspection interval, it is appropriate that the subsequent inspections be perfonned during the third period of each subsequent ten-year Inservice Inspection interval.

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LAR 95-0015 Page 3 This proposed change will allow the visual inspection to be perfonned any time within the third period of the second ISI interval, thus allowing added flexibility in performing the inspections.

Under the proposed change, the required visual inspections will be perfonned again in the third meiod of the third and fourth ten year ISIint, rvals.

No damage or degradation was found during the visual inspections of these components during the third refueling outage, fourth refueling outage or first ten year ISI.

Since, under the proposed change, the required inspections will continue to be performed on a regular basis, v/hich is determined by the method accepted for scheduling inspections of ASME Code Section XI components, there will be no adverse effect on plant safety.

The proposed revision of TS SR 4.4.5.8 also removes the obsolete statement referrint. to the performance of the inspections which were completed during the third and fourth refueling outages. This is an administrative change and will have no adverse effect on plant safety.

SIGNIFICANT ll AZARDS CONSIDER ATION:

The Nuclear Regulatory Commission has provided standards in 10 CFR 50.92(c) for detennining whether a significant hazard exists due to a proposed amendment to an Operating License for a facility. A proposed amendment involves no significant hazards consideration if operation of the facility in accordance with the proposed changes would: (1) No', involve a significant increase in the probability or consequences of an accident previously evaluated;(2) Not create tne possibility of a new or different kind of accident from any accident previously evaluated; or (3) Not involve a significant reduction in a margin of safety. The Davis Ilesse Nuclear Power Strtion has reviewed the proposed changes and detennined that a significant hazards consideution does not exist because operation of the Davis llesse Nuclear Power Station, Unit No.1, in accordance with these changes would:

la Not involve a significant increase in the probability of an accident previously evaluated because no change is being made to any accident initiator. No presiously analyzed accident scenario is changed, and initiating conditions and assumptions remain as previously analyzed. The proposed change to Technical Specification (TS) Surveillance Requirement (SR) 4.4.5.8, to allow performance of required visual inspections of the secured internal auxiliary feedwater header, header to shroud attachment welds, and the external header thennal sleeves during the third penod of the ten year Inservice Inspection Interval, does not affect any Updated Safety Analysis Report (USAR) accident initiators. These inspections will continue to take place at a prescribed time interval scheduled similar to American Society of Mechanical Engineers (ASME) lloiler and Pressuir Vessel Code Section XI components. Therefore,it can be concluded that the proposed change does not involve a significant increase in the probability of an accident previously evaluated.

LAR 954X)l5 Page 4

' lb. Not involve a significant increase in the consequences of an accident previously evaluated because the proposed change does not affect accident conditions or assumptions used in evaluating the radiological consequences of an accident. The proposed change does not aher the source term, containment isolation or allowable radiological releases.

2. Not create the possibility of a new or different kind of accident from any accident previously evaluated because the proposed change does not alter the way the plant is operated, and no new or different failure modes have been defined for any plant system or component important to safety, nor has any limiting single failure been identified as a result of the proposed changes.

These inspections were established to ensure that there are no new failure mechanisms resulting from these components. These inspections will continue to take place in the third period of each inservice inspection interval. No new or different types of failures or accident initiators are introduced by the proposed changes.

3. Not involve a significant reduction in a margin of safety because visual inspections will be performed on a prescribed frequency that is consistent with the schedules established for ASME Code components in accordance with the ASME Code Section XI.

CONCl,USION:

On the basis of the above, the Davis Desse Nuclear Power Station has determined that the License Amendment Request does not constitute a significant hazards consideration.

Furthermore, as this License Amendment Request concerns a proposed change to the Technical Specifications that must be reviewed by the Nuclear Regulatory Commission, this License Amendment Request does not constitute an unreviewed safety question.

ATTACllMENT:

Attached is the proposed marked-up change to the Operating License.

REFERENCES:

1. DBNPS Operating License NPF-3, Appendix A Technical Specifications through Amendment No. 215.

2. DBNpS Updated Safety Analysis Report through Revision 20.

3. Licensee Event Report 82-019 dated April 30,1982, and revised May 28,1982.

4. NRC Safety Evaluation Report dated August 20,1982,"Once Through Steam Generator Repair and Auxiliary Feedwater Sy tem Modifications"(Toledo Edison Log Number 1064).

LAR 95-0015 Page 5 5.' NRC License Amendment No. 62 to Facility Operating License No. NPF-3, dated Septembcr 30,1983 (Toledo Edison Log Number 1376).

6. ASME Boiler and Pressure Vessel Code,Section XI,1986 Edition "No Addenda."

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7. Toledo Edisor, letter Serial Number 845, dated August 6,1982 to Division of Operating Reactors, United States Nuclear Regulatory Commission.

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