ML050130230
| ML050130230 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 01/12/2005 |
| From: | Grecheck E Dominion, Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 04-697 | |
| Download: ML050130230 (6) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY
- RICHMOND, VIRGINIA 23261 January 12, 2005 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Serial No.04-697 NL&OS/ETS RO Docket Nos. 50-338 License Nos. NPF-4 50-339 N PF-7 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)
NORTH ANNA POWER STATION UNITS 1 AND 2 CLARIFICATION OF SAFETY EVALUATION REPORTS FOR TECHNICAL SPECIFICATIONS CHANGE REQUEST TO PERMIT USE OF FRAMATOME FUEL In letters dated April 1 and August 20, 2004, the NRC issued license amendments that approved the use of Framatome Advanced Mark-BW fuel. Dominion has reviewed both comprehensive Safety Evaluation Reports (SERs) and identified several areas within the reports that warrant further clarification. Each item involves language or numerical values within the SERs that could be subject to differing interpretations. The enclosed clarifications are proposed in order to minimize future uncertainty regarding implementation of the commitments associated with the license amendments. The areas of concern were discussed in telephone conference calls with the NRC staff on October 13 and November 3, 2004. The attachment to this letter provides a description of the areas of concern and the proposed resolution.
Should you have any questions or require additional information, please contact Mr. Thomas Shaub at (804) 273-2763.
Very truly yours, Eugene S. Grecheck Vice President - Nuclear Support Services Attach men t Commitments made in this letter: None
cc:
U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23T85 Atlanta, Georgia 30303 Mr. J. E. Reasor, Jr.
Old Dominion Electric Cooperative lnnsbrook Corporate Center 4201 Dominion Blvd.
Suite 300 Glen Allen, Virginia 23060 Mr. M. S. King NRC Senior Resident Inspector North Anna Power Station Mr. S. R. Monarque NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North 1 1555 Rockville Pike Mail Stop 8-H12 Rockville, Maryland 20852 SN: 04-697 Docket Nos. : 50-338/339 Page 2 of 2
Attachment Serial No.04-697 Clarification of NRC Safety Evaluation Reports Technical Specifications Change Requests Use of Framatome Advanced Mark-BW Fuel Virginia Electric and Power Company (Dominion)
North Anna Power Station Units 1 and 2
Serial No.: 04-697 Docket Nos. : 50-338/339 Attachment Page 1 of 3 Areas of Concern Identified in the Framatome Fuel Transition SERs North Anna Units 1 and 2 Area of Concern 1 In Safety Evaluation Report (SER) Section 3.6.4.2.8, (Units 1 and 2) the intent of the second paragraph is unclear. Framatome design basis DNB analysis for Advanced Mark BW fuel supports an FAH limit value greater than the 1.49 that applies to the current fuel. The last sentence states: If in the future the higher nuclear enthalpy rise hot-channel factor is desired, the licensee will need to request a TS change and submit the associated justification. This constraint is inconsistent with the intent and NRC guidance for COLR use, which allows licensees to use the listed approved methods to revise COLR limits without NRC approval.
Dominion Clarification In the October 13, 2004 phone call, the NRC stated that this constraint was based on a statement in Section 4.2.1 1 of the attachment to Dominions letter dated March 28, 2002 (Serial No.02-167). The statement is as follows: The design value F A H ~
for normal operation is defined in the plant Technical Specifications and is evaluated for its impact on thermal and hydraulic design criteria for each reload core.
The intent of this statement was to establish that F A H ~
is a core operating limit that is among those listed in the Technical Specifications (TS 5.6.5, item 8) and is required to be established/evaluated each reload.
The text of Section 4.2.1 1 (following the statement above) presents the limit expression for FAH~ in symbolic form, with the notation that the applicable limit is specified in the Core Operating Limits Report. Only the approved methodologies for establishing F A H ~
are included in Technical Specifications. The actual F A H ~
limit is contained in the COLR and reported to the NRC for every operating cycle. Dominion will continue to evaluate F A ~ N in accordance with Technical Specifications for each operating cycle and retain the ability to revise COLR limits using the listed methodologies without prior NRC approval.
It is recommended that the second paragraph to SER Section 3.6.4.2.8 be revised to read as follows, to reflect the relationship between the North Anna COLR and Technical Specifications Section 5.6.5:
The nuclear enthalpy rise hot-channel factor is defined as the ratio of the integral of linear power along the rod with the highest integrated power to the average rod power.
The current limit is 1.49, as specified in the cycle-specific Core Operating Limits Reports for both North Anna Units 1 and 2. Eventually, the licensee would like to increase the nuclear enthalpy rise hot-channel factor. Future increases in the nuclear enthalpy rise hot-channel factor limit can be made, providing the revised limit is established using the listed methodologies in Section 5.6.5 of the North Anna Technical Specifications.
Serial No.: 04-697 Docket Nos. : 50-338/339 Attachment Page 2 of 3 Area of Concern 2 In Safety Evaluation Report (SER) Section 3.6.4.4.2 (Units 1 and 2), the last paragraph states that SDL values are defined in NAPS UFSAR Rev. 39 Section 4.4.1.2. The existing UFSAR does not contain information regarding SDL values for Advanced Mark-BW fuel.
Dominion Clarification The cited UFSAR section applies only to Westinghouse fuel and discusses fuel temperature and fuel melting design data. The correct reference for the SDL values is located in Section 4.4.2, page 51 of Dominion letter dated March 28, 2002 (Serial No.
02-1 67).
Area of Concern 3 In the NRC Safety Evaluation, Section 3.3.4, (Unit 1 only), the NRC SER states, "In its November 10, 2003 letter, the licensee committed to include this Forslund-Rohsenow penalty assessment in the North Anna-specific LBLOCA models, calculate the penalty with each application of the methodologies, and document this PCT penalty in the North Anna UFSAR."
This statement introduces a feature that is not in the written commitment, namely, the clause "calculate the penalty with each application of the methodologies." Dominion letter (Serial No. 03-31 3G) dated November 10, 2003, states the commitment as follows: "Add a penalty (currently 64°F) to the peak cladding temperature for both North Anna units, calculated by disabling the Forslund-Rohsenow correlation for rod-to-droplet heat transfer (on the hot rod) when Twa1l > Tmin. This departure from the methodology in the approved RLBLOCA topical, EMF-21 03(P)(A),
will be documented in the North Anna UFSAR." The commitment statement did not specifically address future recalculation of the PCT penalty.
The intent of the commitment was to initially apply the 64°F penalty calculated for the limiting unit's transient to both units, but for future applications of the RLBLOCA methodology, one of two possible actions would be taken: 1) assess and apply the 64°F penalty or 2) recalculate a revised penalty, if desired.
Dominion Clarification The description in Section 3.3.4 of the Unit 1 SER is consistent with Dominion's interpretation and application of the original commitment, except in two specific areas.
The following changes are recommended to reflect this understanding and to make the language consistent with the actions that NRC has approved in the Unit 1 SER.
- 1) In Section 3.3.4, revise the sixth sentence to read: "In its November 10, 2003, letter, the licensee committed to include this Forslund-Rohsenow penalty assessment in the North Anna-specific LBLOCA models, and document this PCT penalty in the North Anna UFSAR."
Serial No.: 04-697 Docket Nos.: 50-338/339 Attachment Page 3 of 3
- 2) In Section 3.3.4, revise the last sentence to read: As such, the NRC staff concurs with this implementation of the commitment and finds the licensees actions acceptable.
Area of Concern 4 The first sentence in the second paragraph of Section 3.3.6 (Units 1 and 2) of the NRC SER states, the licensee provided sensitivity studies justifying the omission of fuel pellet relocation....I1 This statement is inaccurate.
Dominion Clarification Revise the subject sentence to read: By letter dated September 5, 2003, the licensee referred to previous Framatome ANP sensitivity studies justifying the omission of fuel pellet relocation from the LBLOCA methodology, and provided confirmation that these studies assumed a peak linear heat rate that bounds North Anna.