ML20078H457
| ML20078H457 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 11/10/1994 |
| From: | Roe J Office of Nuclear Reactor Regulation |
| To: | COMMONWEALTH EDISON CO. |
| Shared Package | |
| ML20078H460 | List: |
| References | |
| NUDOCS 9411170289 | |
| Download: ML20078H457 (8) | |
Text
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UNITED STATES OF AMERICA NUCLEAR REAULATORY COMMISSION In the matter of
)
)
COMMONWEALTH EDISON COMPAE.'
)
Docket No. 50-237
)
(Dresden Nuclear Pomr Station,
)
Unit 2)
)
EXEMPTION 1.
Common'realth Edison Company (Comed, the licensee) is the holder of Facility 0parating License No. DPR-19, which authorizes operation of the Dresden Nuclear Power Station, Unit 2 (the facility), at a steady-state power level not in excess of 2527 megawatts thermal. The facility is a boiling water reactor located at the licensee's site in Grundy County, Illinois. This liceme provides, among other things, that the facility is subject to all rules, regulations, and Orders of the Nuclear Regulatory Commission (the Commission) now or hereafter in effect.
II.
By letter dated October 28, 1994, pursuant to 10 CFR 50.12(a), Comed requested a schedular exemption for Dresden, Unit 2, from the 18-month test interval for a Type A Integrated Leak Rate Test (ILRT) as required by 10 CFR Part 50, Appendix J, Section III.A.6.(b). The exemption is requested to avoid a potential reactor shut down to perform the Type A test.
Due to two forced outages, Comed has had to reschedule the Dresden, Unit 2, refueling outage from September 1994 to July 1995.
Subsequently, Comed requested a maximum extension of up to an additional 242 days for the 18-month Appendix J test interval for a Type A test. The Type A test can not be performed during power operation.
9411170289 941110 DR ADOCK 05000237 PDR
' III.
In its letter dated October 28, 1994, Comed requested a one-time exemption from the 18-month Type A test interval requirement of Appendix J.
Comed has provided leakage test results and maintenance information for the past two outage testing programs. The two consecutive Type A ILRT failures that placed Dresden, Unit 2, on the accelerated test schedule were because of the addition of the Type B and C test leakage results to the Type A leakage rate - not problems with the Type A boundaries.
The minimum pathway data from the last two Unit 2 refueling outages (D2R12 and D2R13) indicate that, on a minimum pathway basis, the quality of primary containment does not degrade excessively through the course of the fuel cycle. The total containment leakage rate minus the Type B and C leakages for the last two Type A test failures during D2R12 and D2R13 are 285.5 standard cubic feet per hour (scfh) and 302.62 scfh, respectively. These values are 47 percent and 50 percent of the Type A ILRT acceptance criteria of 610.56 scfh (0.75L,). The acceptance criteria are from the Dresden, Unit 2, Technical Specification (TS) Section 3.7.A.2.b.(1).
During the D2R12 refueling outage, the Type A ILRT failed due to a leak of the inboard flange of the reactor building to suppression chamber vacuum breaker valve (2-1601-20A). This leakage was quantified to be 12720.05 scfh.
If this did not occur, the Type A ILRT results would have been 543.40 scfh, which is less than the TS limit of 610.56 scfh (0.75L,).
During the D2R13 refueling outage, the Type A test failed due to the as-found minimum pathway leakage of primary containment isolation valves found during Type B i
and C testing.
The volumes that were the major contributors to this failure are as follows:
The "B" feedwater line isolation check valves (2-220-588 and
2-220-62B), shutdown cooling isolation valves (2-1001-1A, 2-1001-18, 2-1001-2A, 2-1001-2B and 2-1001-20), reactor water clean-up isolation valves (2-1201, 2-1201-1A, 2-1201-3, 2-1299-004 and 2-1299-005), low pressure coolant injection containment spray isolation valves (2-1501-27B and 2-1501-288), high pressure coolant injection drain pot to suppression chamber valves (2-2301-34 and 2-2301-71), traversing incore probe purge check valve (2-4799-514),
electrical penetration X-202W, and drywell bellow X-113. The total minimum pathway leakage for these volumes was 685.75 scfh.
Each of the above valves and volumes were repaired during the refueling outage and subsequently passed post-maintenance Type B and C tests prior to restart of Unit 2 for the current operating cycle.
At the time the pertinent requirements of Appendix J were established (1973), the typical nuclear power plant fuel cycle lasted 12 months.
Section III.A.6.(b) may have been written to require a Type A test at every refueling outage - specifying a numerical cap on the interval to prevent extreme cases of very long intervals (caused by extended shutdowns or operations at reduced power) between tests. An 18-month cap was reasonable for 12-month fuel cycles, but with the current 18-and 24-month fuel cycles, it clearly is not sufficient. The intent of Section III.A.6.(b) is to increase the testing frequency for a containment that exhibits leakage problems, but not to increase it so much that special shutdowns are required. Refueling outages are the only reasonable time to perform Type A test, since most plants do not have extended shutdowns at any other time.
In order to add an additional margin of safety and to account for the possible increase in the leakage of a containment penetration, the licensee
j
' has imposed an administrative limit for Dresden, Unit 2, on the total maximum j
allowable containment leakage rate until the completion of the current operating cycle. This limit will be 519.0 scfh, which is 85 percent of the TS limit of 610.56 scfh (0.75L,). All additional minimum pathway leakage will be added to the current total as operational Type B and C leak rate tests are performed during the current operating cycle.
These corrective measures taken should reduce the chances of D2R14 failing the "As Found" Type A ILRT test.
IV.
l The staff has reviewed Comed's submittal regarding the Appendix J test interval exemption request.
Based on the above, the staff concludes that the licensee's corrective action and administrative leakage limit have reduced the 1
likelihood of excessive leakage during the proposed extension of the Type A test interval.
Further, considering the intent of the 18-month interval cap and its relation to longer fuel cycles, the staff finds that the safety J
benefit to be derived from performing a Type A test at 18 months rather than 26 months does not justify the hardship of a forced plant shutdown.
Therefore, the staff finds that the requested Type A interval extension should be granted.
This is a one-time exemption from the 18-month Type A test interval requirements as prescribed in 10 CFR Part 50, Appendix J, and is intended to be in effect until July 14, 1995.
In its October 28, 1994, letter, Comed also identified special circumstances. As discussed above, the exemption request is for a short duration relative to the 18-month requirement. This meets a criterion for a special circumstance per 10 CFR 50.12(a)(2)(v),
i.e., "The exemption would
... s provide only temporary relief from the applicable regulation and the licensee or applicant has made good faith efforts to comply with the regulation."
V.
Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12(a), that (1) this exemption is authorized by law and will not endanger r
life or property or the common defense and security, and is otherwise in the public interest, and (2) the Exemption would provide only temporary relief from the applicable regulation and the, licensee has made good faith efforts to comply with the regulation. Therefore, the Commission hereby grants an exemption as described in Section III above from 10 CFR Part 50, Appendix J, Section III. A.6.(b), to the extent that the 18-month interval for performing the Type A test may be extended for 242 days until July 14, 1995, on a one-time only basis, for Dresden, Unit 2.
Pursuant to 10 CFR 51.32 the Commission has determined that the granting of this Exemption will have no significant impact on the environment (59 FR 56095).
This exemption is effective upon issuance.
FOR THE NUCLEAR REGULATORY COMMISSION Onginal Signed By:
Jack W. Roe, Director Division of Reactor Projects - III/IV Office of Nuclear Reactor Regulation Dated at Rockville, Maryland this 10th day of November 1994 DDCUMENTNAME:G:\\DRESDEN\\DR90723.LhR
- See previous concurrence To riesive e c6py of this document, indicate in the tlot:
'C' = Copy it.
losures *E* = Copy with enclosures *N* = No copy 0FFICE L AiPDlII-2 l ---
PM: PDilA471 BC3CW
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l D:PDIII-2 l m NAME U Moore J. St4V:lm R. Bhhett MZobler R. Capra teet DATE 11/ V 94 11/
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. provide only temporary relief from the applicable regulation and the licensee or applicant has made good faith efforts to comply with the regulation."
V.
Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12(a), that (1) this exemption is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest, and (2) the Exemption would provide only temporary relief from the applicable regulation and the licensee has made good faith efforts to comply with the regulation. Therefore, the Commission hereby grants an exemption as described in Section l'I above from 10 CFR Part 50, Appendix J, Section III. A.6.(b), to the extent ti:at the 18-month interval for performing the Type A test may be extended for 242 days until July 14, 1995, on a one-time only basis, for Dresden, Unit 2.
Pursuant to 10 CFR 51.32 the Commission has determined that the granting of this Exemption will have no significant impact on the environment (59 FR 56095).
This exemption is effective upon issuance.
FOR THE NUCLEAR REGULATORY COMMISSION Original Signed By:
Jack W. Roe, Director Division of Reactor Projects - III/IV Office of Nuclear Reactor Regulation Dated at Rockville, Maryland this 10th day of November 1994 DOCUMENTNAME:G:\\DRESDEN\\DR90723.LkjR
- See previous concurrence To r2ceive a oopy of this document. Indicate in the dbt:
'C' = Copy it t _7dosures *E* = Copy with enclosures "N"
= No copy 0FFICE L A iPI.)lI I-2 l6 PM: PDf Dl47'l BC3CW
'l OGC*
l D:PDIII-2 l E NAME U Moore J.
StMt(: 1m R. Bltthett MZobler R. Capra qe t DATE ll/ P/94 11/Of94 ll/}h/94 11/10/94 11/to/94 0FFICE ADR:PDIV-5 #
D:DRPF l t l
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NAME E. Adens #
J.t IW fu DATE 11/ A4 111(c/94 11/ /94 11/ /94 11/ /94 0FFICIAL RECORD COPY
. provide only temporary relief from the applicable regulation and the licensee or applicant has made good faith efforts to comply with the regulation."
V.
Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12(a), that (1) this exemption is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest, and (2) the Exemption would provide only temporary relief from the applicable regulation and the licensee has made good faith efforts to comply with the regulation. Therefore, the Commission hereby grants an exemption as described in Section III above from 10 CFR Part 50, Appendix J, Section III. A.6.(b), to the extent that the 18-month interval for performing the Type A test may be extended for 242 days until July 14, 1995, on a one-time only basis, for Dresden, Unit 2.
Pursuant to 10 CFR 51.32 the Commission has determined that the granting of this Exemption will have no significant impact on the environment (59 FR
).
This exemption is effective upon issuance.
FOR THE NUCLEAR REGULATORY COMMISSION Jack W. Roe, Director Division of Reactor Projects - III/IV Office of Nuclear Reactor Regulation Dated at Rockville, Maryland
'M this day of November 1994 bd 1A DOCUMENT NAME:G:\\DRESDEN\\DR90723.LTR To receive a chyof this document, indicate in the box: "C" = Copy without enclosures *E" = Copy with fnclosures *N" = No copy 0FFICE L A:PDII!I-2 l&
PM:PDIII-2 i BC:SCSB l
t # '24 W 4, L D:PDIII-2 l NAME Om. Moore J. Stang:lm R. Barrett OGC Nu N///
R. Capra DATE 11/1/94 11/ /94 11/ /94 11/ /0/94" //
11/ /94 0FFICE ADR:PDIV-5 l D:DRPW l
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NAME E. Adensam J. Roe DATE 11/ /94 11/ /94 11/
/94 11/ /94 11/ /94 0FFICIAL RECORD COPY
DISTRIBUTION Docket File PDIll-2 r/f l
CMoore JStang i
Hovember 10, 1994 OGC DOCKET NO.
50-237 MEMORANDUM TO:
Rules Review and Directives Branch Division of Freedom of Information and Publications Services Office of Administration FROM:
Office of Nuclear Reactor Segulation
}
SUBJECT:
CorJonwealth Edison Con.pany - Dresden, Jnit 2 One signed original of the FederalRegister Notice identified below is attached f( r your transmittal to the Office of the Federal Register for publication. Additional conformed copits (
5 ) of the Notice are enclosed for your use.
i Notice of Receipt of Application for Construction Permit (s) and Operating License (s).
Notice of Receipt of Partial Application for Construction Permit (s) and Facility License (s!-
Time for submission of Views on Antitrust matters.
Notice of Consideration of issuance of Amendment to Facility Operating License. (Call with 30-day insert date).
Notice of Receipt of Application for Facility License (s); Notice of Availability of Applicant's i
Environmental Report; and Notice of Consideration of issuance of Facility License (s) and Notice of Opportunity for Hearing.
Notice of Availability of NRC Draft / Final Environmental Statement.
Notice of Limited Work Authorization.
Notice of Availability of Safety Evaluation Report.
Notice of Issuance of Construction Permit (s).
Notice of issuance of Facility Operating License (s) or Amendment (s).
Order.
Exemption.
l Notice of Granting Exemption.
Environmental Assessment.
Notice of Preparation of Environmental Assessment.
Receipt of Petition for Director's Decision Under 10 CFR 2.206.
Issuance of Final Director's Decision Under 10 CFR 2.206.
[ Other:
t i
Office of Nuclear Reactor Regulation l
l" Attachment (s): As stated
Contact:
John F. Stang Telephone: 504-1345 DOCUMENT NAME:
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To receive a cop of this document. hdecate in the box:
"C" = Copy without attachment! enclosure "E" = Copy with attachment / enclosure
- N* = No copy i
OFFICE TLA:PD3-21" i
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DATE 11/10/94 OFFICIAL RECORD COPY