05000271/LER-2004-002, Regarding Revision to LER 2004-002-00 That Provides the Results of the Special Nuclear Material Inventory Discrepancy Discovered on April 04, 2004
| ML042810221 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 09/29/2004 |
| From: | Bronson K Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BVY 04-103 LER 04-002-01 | |
| Download: ML042810221 (12) | |
| Event date: | |
|---|---|
| Report date: | |
| 2712004002R00 - NRC Website | |
text
- -Entergy Entergy Nuclear Northeast Entergy Nuclear Operations, Inc.
Vermont Yankee 185 Old Ferry Rd.
RO. Box 500 Brattleboro, VT 05302 Tel 802-257-5271 September 29, 2004 BVY 04-103 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
Subject:
Vermont Yankee Nuclear Power Station License No. DPR-28, Docket No. 50-271 Reportable Occurrence No. LER 2004-002-01 As defined by 10 CFR 20.2201(d), we are submitting the attached reportable occurrence is LER 2004-002-01. This document is a revision to LER 2004-002-00 that provides the results of the special nuclear material inventory discrepancy discovered on April 04, 2004.
Sincerely, ENTERGY NUCLEAR OPERATIONS, INC.
VERMONT YANKEE Kevin Bronson General Manager cc:
USNRC Region I Administrator USNRC Resident Inspector - VYNPS USNRC Project Manager - VYNPS Vermont Department of Public Service
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Abstract
On 04/20/04, with the reactor shutdown for a refuel outage, an inventory of Special Nuclear Material (SNM) in the Spent Fuel Pool (SFP) revealed that two fuel rod pieces were not in the designated storage location. This condition was reported to the NRC on 04/21/04 pursuant to 10 CFR 50.72 (b)(2)(xi) as NRC Event 40694 for a news release, amended on 05/19/04 to address additional reporting regulations. The two fuel rod pieces were the product of a fuel reconstitution performed in 1979 due to Crud Induced Localized Corrosion (CILC) fuel rod failures identified at Vermont Yankee and elsewhere within the nuclear industry. An investigation team was formed to complete a root cause analysis of the event and to search for the fuel rod pieces. The investigation was accomplished primarily by completing an inspection of the SFP, document reviews, interviews with VY employees (past and present) and interviews with contractors that had been associated with SFP activities and radioactive waste operations at Vermont Yankee. On 07/13/04 the two fuel rod pieces were located in the SFP on top of the channel rack in a cylindrical liner specifically designed by General Electric for storing fuel rod pieces.
On 07/13/04, the NRC was notified of this development in the investigation, and was documented as NRC Event 40867.
NRC FORM 366 (6-2004)
(If more space is required, use additional copies of NRC Forn 366A)
DESCRIPTION
On 04/20/04, with the reactor shutdown for a refuel outage, an inventory of Special Nuclear Material (SNM) in the Spent Fuel Pool (SFP) revealed that two fuel rod pieces, approximately 0.493 inches in diameter by approximately 9 inches and 17.75 inches in length were not in their designated storage location. This event was initially reported as NRC Event 40694 pursuant to 10 CFR 50.72 (b)(2)(xi) on 04/21/04 in connection with a planned press release. An update to this notification was completed on 05/19/04 pursuant to 10 CFR 20.2201 (a)(1)(ii), for missing radioactive material" and under 10 CFR 74.11 for lost SNM".
The two fuel rod pieces were the result of a fuel inspection, sipping, and reconstitution campaign that was performed in 1979 due to Crud Induced Localized Corrosion (CILC) fuel rod failures identified at Vermont Yankee (VY) and elsewhere within the nuclear industry. The two fuel rod pieces were believed to have been placed in narrow pipes that are an integral part of a larger stainless steel container and stored at the bottom of the SFP that is approximately 40 feet in depth. This container was only designed for storing the fuel rod pieces in the SFP and did not have the necessary shielding to allow for safe removal from the underwater environment.
The Special Nuclear Material Investigation Team (SNMIT) was formed to complete a root cause analysis of the event and to search for the two fuel rod pieces. The investigation was accomplished primarily by completing an inspection of the SFP, document reviews, interviews with VY employees (past and present) and interviews with contractors who have been associated with SFP activities and radioactive waste operations.
On 07/08/04, a forty-five inch by five inch, aluminum cylinder (liner) with a screw cap on one end and a one and a half inch hex nut on the opposite end was identified as potentially containing the two fuel rod pieces.
This item was purchased from GE Vallecitos Nuclear Center in Pleasanton, CA and received at VY on 08/07/79. A review of the recently generated SFP video tapes established the location of the liner, situated horizontally on top of the fuel channel storage rack against the south wall of the SFP. A recovery plan was developed and on 07/13/04 the liner was opened and inspected, revealing the two fuel rod pieces. Verification measurements were performed and documented with underwater video equipment. To provide assurance that the fuel rod pieces found in the liner were those in question, GE Vallecitos Nuclear Center was contacted to determine if any fuel rod pieces, previously sent to them for examination had been returned. The response to this inquiry stated that; due to the destructive nature of post irradiation examination, GE Vallecitos Nuclear Center does not return spent fuel received for examination to the utilities. After examination, spent nuclear fuel is stored on site at their facility until disposal. Additionally, it should be noted that the measured radiation levels of the liner's exterior and the fuel rod pieces is in agreement with the calculated dose rates. On 07/13/04, the NRC was notified that the two fuel rod pieces had been located. This notification was listed as NRC Event 40867.
REGULATORY REPORTING REQUIREMENTS OF 10 CFR 20.2201:
10 CFR 20.2201(b) requires a written report within 30 days after an initial verbal notification is performed in accordance with 10 CFR 20.2201 (a)(1)(ii), for the occurrence of any lost, stolen, or missing licensed material in a quantity 10 times greater than the quantity specified in Appendix C to Part 20. The initial written report (LER 2004-002-00) was submitted on 06/17/04. This report is a revision to the initial written report to communicate the results of the SNM investigation pursuant to 10 CFR 20.2201 (d). The following topics listed below that were previously required to be addressed by 10 CFR 20.2201 (b), have been addressed within this report.
(i)
A description of the licensed material involved, including kind, quantity, and chemical and physical form; and (If more space is required, use additional copies of (if more space is required, use additional copies of (If more space is required, use additionalcopies of (If more space is required, use additional copies of NRC Forrn 366A) c. A verification that the remaining portions of partial fuel rods were in their documeted locations.
No discrepancies noted.
- 2. Performed SFP inspections as described in the response to Topic (v).
- 3. Verified that all spent fuel assemblies stored in the SFP are in their correct locations.
- 4. Performed a methodical review of pertinent documents to gather information used to create timelines of significant events, to identify the current location of the two fuel rod pieces and to analyze potential exit scenarios from the plant.
- 5. Conducted interviews with key personnel who were involved with SNM control. Information obtained from the interviews was successfully used to identify the location of the two fuel rod pieces.
- 6. Provided a preliminary Licensee Event Report [LER 2004-002-00] on 06/17/04 to communicate the status of the investigation, describe the missing radioactive material, provide a public safety assessment and to comply with the reporting requirements of 10 CFR 20.2201 (b).
Interim Corrective Actions:
- 1. SNM accountability forms have been revised to be in compliance with station procedural requirements of OP 0400, "Special Nuclear Material Inventory and Accountability Procedure".
- 2. Re-inventoried SNM in the skimmer pump room, LPRM Box, dunking chambers on the refuel floor, and placed tamper evident tape on SNM containers.
- 4. Station procedures were revised to include the appropriate regulatory reporting requirements for a Loss, Theft or Attempted Theft of SNM.
- 5. Reactor Engineering oversight and assessment of the SNM Process has been increased as demonstrated by the following programmatic and process improvements; a. The SNM inventory was reviewed.
b. A detailed video taped record of fuel assembly serial number verification of the SFP was completed.
c. A re-inventory of non-fuel inventory that was accessible was performed with an independent peer check of both the fuel and non fuel inventories.
d. SNM inventory that could be made tamper evident was done correctly with new standards that meet the current regulation.
e. The two fuel pieces stored in a GE liner were inspected, made tamper evident, and stored in an engineered canister holder so that when performing future SNM physical inventories, the fuel pieces will now be inventoried by verifying the container is sealed and the tamper device is intact.
f. Records for the two fuel pieces were updated and verified.
g. RE Management performed discussions and coaching with the RE Department that covered the causes of the missing fuel pieces that included current regulatory requirements and event precursors.
(If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A)
Table 3: Spent Fuel Rod Estimated Dose Rate Summary - Unshielded 17.75" Fuel Rod Piece (rad/hr in air) 9" Fuel Rod Piece (rad/hr in air)
Years Dose Rate Dose Rate Dose Rate Dose Rate Dose Rate Dose Rate Decay Contact at 1 ft at 3 ft Contact at 1 ft at 3 ft o
3.52E+06 5.55E+04 7.12E+03 3.40E+06 3.24E+04 3.66E+03 1
1.12E+04 1.84E+02 2.37E+01 1.08E+04 1.07E+02 1.22E+01 2
5.48E+03 9.05E+01 1.17E+01 5.28E+03 5.30E+01 6.03E+OO 4
3.25E+03 5.40E+01 6.98E+00 3.12E+03 3.16E+01 3.60E+OO 10 1.60E+03 2.69E+01 3.49E+00 1.54E+03 1.59E+01 1.81 E+00 15 1.28E+03 2.15E+01 2.79E+00 1.23E+03 1.27E+01 1.43E+00 20 1.1 OE+03 1.86E+01 2.41 E+0O 1.06E+03 1.09E+01 1.24E+00 25 9.65E+02 1.63E+01 2.11 E+00 9.27E+02 9.59E+00 1.09E+00