ML051860390
| ML051860390 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 07/09/2005 |
| From: | Pickett D NRC/NRR/DLPM/LPD2 |
| To: | Office of Nuclear Reactor Regulation |
| Pickett D, NRR/DLPM, 415-1364 | |
| References | |
| TAC MC7340, TAC MC7341 | |
| Download: ML051860390 (4) | |
Text
July 9, 2005 MEMORANDUM TO: FILE FROM:
Douglas V. Pickett, Senior Project Manager, Section 2
/RA/
Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation
SUBJECT:
SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 CLOSURE OF TAC NOS. MC7340 AND MC7341 The purpose of this memorandum is to document closure of TAC Nos. MC7340 and MC7341 for the Sequoyah Nuclear Plant, Units 1 and 2.
By letter dated June 17, 2005 (ML051810267), the Tennessee Valley Authority (the licensee) submitted a one-time emergency technical specification change to extend the allowed outage time for the 1B-B emergency diesel generator for the Sequoyah Nuclear Plant, Units 1 and 2.
TAC Nos. MC7340 and MC7341 were opened to track the staffs activities for this licensing action.
By letter dated June 21, 2005 (ML051810255), the licensee withdrew the above request.
Therefore, TAC Nos. MC7340 and MC7341 are closed.
Following the withdrawal, the licensee requested feedback from the staff regarding the technical adequacy of their submittal. The attachment, which includes staff feedback, was shared via e-mail with the licensee.
Docket Nos. 50-327 and 50-328
Attachment:
As stated
ML051860390 NRR-106 OFFICE PM:LPDII-2 LA:LPDII-2 SC:LPDII-2 NAME DPickett BClayton BMozafari for MMarshall DATE 7 / 07 /05 7 / 07 /05 7 / 09 /05
Sequoyah Emergency Technical Specification Change 05-05 NRR Feedback
1.0 BACKGROUND
By letter dated June 17, 2005, TVA submitted an emergency technical specification application (05-05) extending the allowed outage time (AOT) for the 1B-B emergency diesel generator (EDG) for the Sequoyah Nuclear Plant, Units 1 & 2. After the amendment application was withdrawn by letter dated June 21, 2005, the licensee requested feedback from the staff in support of lessons learned.
2.0
SUMMARY
The staff review was not complete when the licensee requested that the review effort be terminated. However, the staff was able to conclude that additional documentation would have been required in the following areas:
Documentation of Emergency Basis 10 CFR 50.91(a)(5) states:
Whenever an emergency situation exists, a licensee requesting an amendment must explain why this emergency situation occurred and why it could not avoid this situation....
From a legal perspective, it would have been difficult to evaluate the "emergency" aspect of the request. The application focused on why the emergency situation occurred but was silent on why the situation could not be avoided. The staff was looking for justification to combat the argument that too much work had been scheduled for the 7-day limiting condition for operation (i.e., the licensee created the emergency situation).
Compensatory Measures The application lacked compensatory measures. The staff has approved several EDG AOT extension requests ranging from 7 to 14 days. In each of our safety evaluations for those extension requests, we identified a number of compensatory measures that the licensee committed to take. NRC's Safety Evaluations supporting the Watts Bar's License Amendment Request (LAR) Re: EDG AOT Extension from 3 to 14 days (ML021840589) and Diablo Canyons LAR Re: EDG AOT Extension from 7 to 14 days (ML041120264) include a number of compensatory measures that the staff was hoping to see.
Reliability of Offsite Power The application included a detailed discussion of the availability and reliability of the emergency diesel generators. A similar discussion of the availability and reliability of Sequoyah's offsite power supplies would have been useful.
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Risk Analysis The licensee did not discuss the risk model employed, including uncertainty (as a minimum, the licensee should have discussed Error Factor or spread data points),
truncation level, quantification tool and potential common cause failure.
Clarification of the quantification baseline values and zero maintenance model. (It appears that the licensee did not use a zero maintenance model.)
Discussion on risk insights based on the risk numbers.
Elaboration of compensatory measures, both quantifiable and non-quantifiable.
Descriptions of the licensees configuration risk management program (i.e., the three-tier approach as related to risk-information).
Clean Technical Specification Pages The application only included marked-up copies of the technical specification pages.
The staff does not have an electronic version of the Sequoyah Technical Specifications and would have needed clean, corrected pages for issuance.