ML19210B082
| ML19210B082 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 01/07/1978 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19210B079 | List: |
| References | |
| NUDOCS 7911040029 | |
| Download: ML19210B082 (4) | |
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UNITED STATES
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t NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 y
p SAFETY EVALUATION BY THE OFFICE OF ?!UCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 36 TO FACILITY OPERATIt:G LICENSE NO. OPR-50 METROPOLITAN EDISON COMPANY
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JERSEY CENTRAL POWER AND LIGHT CC'iPANY pet!NSYLVANIA ELECTRIC C0l#EY THREE MILE ISLAND NUCLEAR STATION, UNIT NO. I DOCKET N0. 56 J9, Introduction By letter dated October 28, 197.7, Metropolitan Edison Company (Met Ed),
requested anendment of the Appendix A Technical Specifications appended to facility Operating License No. DPR-50 for Three Mile Island f!uclear Station, Unit No. 1 (Till-1).
The amendment would revise the def;nition of containment integrity given in the Technical Specifications to permit one door of either the personnel hatch or energency hatch to be open during reactor operation for a period of up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to allow maintenance, repair, or modification, provided the other door of the hatch is leak tested nd found to meet the local leak rate criteria for door seals within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to the raintenance, repair, or modifi-cation.
Bac kground On September 20, 1977, Met Ed discovered that both doors of the personnel access hatch (airlock) to the containment had been left open for approxi-rrately 10 minutes.
This condition was a violation of the facility's Technical Specifications.
A contributing reason for the occurrence of this condition was deterioration of the mechanical interlock system which was designed to prevent such occurrences.
In order to correct this condition, Met Ed has comitted to n.cdify the door hardware to reduce the probability of future deterioration.
These modifications will be made in two phases:
Phase I is a minor modification (modification of the latching bar interlock arm) which will correct the present deterioration; Phase II is a rnore complex modification involving 3 r;7 G p@
e the strut bearinc, that is designed to reduce the Drebability of future deterioration of the interlock system.
Met Ed has proposed to implemn:
the. Phase Il modification during the 1978 refueling outage.
As for the Phase I modification, Pet Ed is prepared to make this chance at this tire.
The TMI-l Technical Specifications, as presently written, do not permit cne of the doors to be open during reactor cre ation except for passage of personnel.
Eccause of this requirement and be-cau n each door rust we open during a portion of the tire it is being repaired, Met Ed cannot effect the Phase ! modification withcut shutting down the reactor.
Met Ed, however, does nct believe that safety considerations recuire shutdown of the reactor to effect these repairs, and to support his position cites Section 4.4.1.2.4b of the TMI-l Technical Specifications which allows reactor operation for up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> while repairing localized excessive leakage.
Accordingly, Met Ed has requested that the definition of containrent integrity aiven in the TMI-l Technical Specifications be modified to allow one door of a cer-sonnel or energency hatch to be_open for up to.a8 hours provided the other door is tested and found 'to meet the local leak rate criteria for door seals prior to maintenance.
Evaluation As noted above, Met Ed supports the request for revision of the TM!-l Technical Specifications with respect to the definition of containment integrity, by noting that the Technicai 5;ecifications presently allo..
reactor operation for up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> while excessive localized leakage of a containment penetration is being recaired.
Met Ed, however, is not requesting an analogous provision which would allow them to make repairs to the containnent hatch doors while there was excessive lealace of.the door seals.
Rather, they are only asking for permission to keep one of the doors open fcr repair, maintenance, or modification after they have closed the other door of the hatch and deronstrated that the seals on the other door meet th?ir leakage rate criteria.
In other words, in this case leakage is within specification for the exception period, rather than out of specification.
It is noted that Met Ed's request would provide the flexibility of opera, tion normally granted in facility licenses currently being issued to new plants.
That is, current licenses normally grant permission for an airlock to be inoperable for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> during reactor operation. provided 'one door is maintained clo4ed.
This type of pro-vision is comon to many redundant safety systens.
Basically, it permits short-term inoperability of one of the redundant units during repair or maintenance provided the other unit rerains operable.
Such provisions are judged acceptable if the redundant unit alone is cacable of performing the intended safety function.
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. We find that such is the case with Met Ed's proposed revision to the THI-l Technical Specifications. That is, either door is capable of providing the intended safety function provided it is closed and has an acceptable leakage rate.
We have discussed with Met Ed the fact that they have requested a 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> exception period while the exception period normally granted is 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. They acreed that the necessary Phase I repairs should be capable of being completed in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and agreed to modification of their proposed revision accordingly.
Certain clarifying editorial changes in the proposed revision were also discussed with and agreed to by Met Ed.
Because the event which prompted the proposed re<ision of the Technital Specifications arose as a result of deterioration of an interlock system, we are adding a Technical Specification provision which will require periodic testing of interlock operability and appropriate corrective action if the interlock is found to not be operable.
This addition has also been discussed with and agreed to by Met Ed.
Based on the foregoing, we find that Met Ed's proposed revision would not increase the probability or consequences of an accident or malfunctio.1 considered in the Final Safaty Analysis Report (FSAR) because at least one of the hatch doors will still be required to be closed at all times and, further, will Fsve been demonstrated to meet the door seal leakage criteria within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to the exception period.
Further, the proposed revision will permit improvement of a condition which has allowed a significant malfunction in the past, without requiring a costly temporary shutdown of the facility.
We find that the proposed revision will not create a new type of accident not considered in the FSAR because, as is presently the case, at least one door will always be required to be closed and the modification to the door mechanism will help improve the assurance that this is the case.
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o 4-We further find that the proposed revision will not decrease the margin of safety as stated in the basis for any technical specification because it will still be required that at least one door be closed and it will additionally be required that the leak tightness of its seals be verified within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to the exceptien period.
Environmental Consideration We have determined that the amendment does not authorize a change in ef fluent types or total amounts nor an increase in po..>er level and will not result in any significant environmsntal iroact.
Having made this determination, we have further concluded that the amendment involves an action which is insignificant frcn the stand-point of environmental impact and, pursuant to 10 CFR ;51.5(d)(4),
that an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in conr.ection with the issuance of tnis amendment, Conclusion We have concluded, based on the considerations discussed above, tha t:
(1) because the amendment does not involve a significant in-crease in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consider-ation, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposeo manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the cocon defense and security or to the health and safety of the public.
Dated: January 7,1978 h
. 1557 G7
UNITEDSTATESNUCLEARREGULdORYCOMMISSION DOCKET NO. 50-289 METROPOLITAN EDISON COMPANY JERSEY CENTRAL POWER AND LIGH_T COMPANY PEN'lSYLVANIA ELECTRIC COMPANY NOTICE OF ISSUANCE OF AMENDMENT TO FACILITY OPERATING LICENSE The U. S. Nuclear Regulatory Commission (the Commission) has issued Amendment No. 36 to Facility Operating License No. DPR-50, issued to Metropolitan Edison. Company, Jersey Central Power and Light Company and Pennsylvania Electric Company (the licensees), which revised Technical Specifications for operation of the Three Mile Island Nuclear Station, Unit No.1 (the facility) located in Dauphin County, Pennsylvania. The amendment is effective as of its date of issuance.
The amendment revises the definition of containment integrity with respect to airlock maintenance, repair or modification and adds surveillance requirements for the interlock systems of airlocks.
The application for the amendment complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations. The Commission has made appropriate findings as required by-the Act and the-Commission's rules and regulations in 10 CFR Chapter I, which are set forth in the license amendment.
Prior public notice of this amendment was not required since the amendment does not involve a significant hazards considaration.
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. The Commission has detemined that the issuance of this amendment will not result in any significant environmental impact and that pursuant to 10 CFR 651.5(d)(4) an environmental impact statement, or negative declaration and environmental impact appraisal need not be prepared in connection with issuance of this amendment.
For further details with respect to this action, see (1) the application for amendment dated October 28, 1977, (2) Mendment No. 36 to License No. DPR-50, and (3) the Commission's related Safety Evaluation. All of these items are available for public inspection at the Commission's Public Document Room, 1717 H Street, N. W., Washington, D. C. and at the Government Publications Section, State Library of Pennsylvania, Box 1601 (Education Building),
Harrisburg, Pennsylvania. A copy of items (2) and (3) may be obtained upon request addresse,d to the U. S. Nuclear Regulatory Commission, Washington, D. C.
20555, Attention:
Director, Division of Operating Reactors.
Dated at Bethesda, Maryland, this 7th day of January 1978.
FOR THE NUCLEAR REGULATORY COP. MISSION n
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'a Robert W. Reid, Chief Operating Peactors Branch #4
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