05000133/LER-2004-001-01, Three Missing Fuel Rod Segments

Three Missing Fuel Rod Segments

ML043340386
Person / Time
Site:	Humboldt Bay
Issue date:	11/19/2004
From:	Rueger G Pacific Gas & Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
HBL-04-026 LER 04-001-01
Download: ML043340386 (16)

LER-2004-001, Three Missing Fuel Rod Segments

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(v), Loss of Safety Function
1332004001R01 - NRC Website

text

Pacific Gas and Electric Company..

Gregory M. Rueger US Mail:

Senior Vice President-Mail Code B32 Generation and Pacific Gas and Electric Company Chief Nuclear Officer PO Box 770000 November 19, 2004 San Francisco, CA 94177-0001 Overnight Mail:

Mail Code B32 PG&E Letter HBL-04-026 Pacific Gas and Electric Company 77 Beale Street. 32nd Floor San Francisco, CA 94105-1814 U.S. Nuclear Regulatory Commission 415.973.4684 ATTN: Document Control Desk Fax: 415.973.2313 Washington, DC 20555-0001 Docket No. 50-133, OL-DPR-7 Humboldt Bay Power Plant, Unit 3 Licensee Event Report 2004-001-01 Three Missing Fuel Rod Seaments

Dear Commissioners and Staff:

In accordance with 10 CFR 20.2201 (b)(2)(i), PG&E is submitting the enclosed Revision 1 to Licensee Event Report (LER) 2004-001, regarding three missing 18-inch fuel rod segments. This LER revision supercedes LER 2004-001-00, submitted via HBL-04-20, dated August 16, 2004. This LER revision provides a status update to the investigation regarding the missing fuel rod segments and commits to submittal of a subsequent revision when the investigation and causal analysis are completed. Revision bars in the left hand margin note the changes.

This event did not adversely affect the health and safety of the public.

Sincerely, Gregory M. Rueger Enclosure cc:

Emilio M. Garcia John B. Hickman Bruce S. Mallett PG Fossil Gen HBPP Humboldt Distribution

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/30/2007 16-2004)

Estimated burden per response to comply with this mandatory collection request: 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br />. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the Records and FOIA/Privacy Service Branch (T-5 F52) U.S. Nuclear Regulatory Commission, LICENSEE EVENT REPORT (LER)

Washington, DC 20555-01, or by intenmet e-mail to infocollectswnrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104) Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control (See reverse for required number of number, the NRC may not conduct or sponsor, and a person is not required to respond digits/characters for each block) to, the information collection.

3. PAGE Humboldt Bay Power Plant Unit 3 05000133 1 OF 15

4. TITLE Three Missing Fuel Rod Segments

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMB REV MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 06 30 2004 2004 - 001 -

01 11 19 2004

9. OPERATING MODE 11.THIS REPORT IS SUBMITTED PURSUANT TOTHE REQUIREMENTS OF 10 CFR§: (Checkallthatapply) 0 20.2201(b) 0 20.2203(aX3Xi) 0 50.73(aX2Xi)(C) 0 50.73(aX2Xvii)

N/A 0 202201(d) 0 20.2203(aX3)(ii) 0 50.73(aX2Xii)(A) 0 50.73(aX2)(viii)(A) 0 20.2203(aXI) 0 20.2203(a)(4) 0 S0.73(aX2Xii)(B) 0 50.73(aX2)(viii)(B) l0 20.2203(aX2Xi) 0 50.36(c)(I)(i)(A)

E 50.73(a)(2Xiii) 0 50.73(a)(2)(ix)(A)

10. POWER LEVEL 0 20.2203(a)(2Xii) 0 50.36(c)(l)(iiXA) 0 50.73(a)(2)(iv)(A) 0 50.73(a)(2)(x) o 20.2203(a)(2)(iii) 0 50.36(c)(2) 0 50.73(a)(2)(v)(A) 0 73.71(a)(4) 0 20.2203(a)(2)(iv) 0 50.46(a)(3)ii) 0 50.73(a)(2)(v)(B) 0 73.71(a)(5) 0 0 20.2203(a)(2)(v) 0 50.73(a)(2)(i)(A) 0 50.73(a)(2)(vXC) 0 OTHER o 20.2203(a)(2)(vi) 0 50.73(aX2Xi)(B) 0 50.73(a)(2)(v)(D)

Specify in Abstract below or in NRC Form 366A

12. LICENSEE CONTACT FOR THIS LER FACILITY NAME TELEPHONE NUMBER (Include Area Code)

David Sokolsky - Senior Regulatory Services Engineer (707) 444-0801CAUSE SYSTEM COMPONENT MFATNUR ER TO l

l

CAUSE

SYSTEM COMPONENT MANU RERTA1PIE FACURR T EIXFACTURER TO EPIX N/A

14. SUPPLEMENTAL REPORT EXPECTED

15. EXPECTED MONTH DAY YEAR SUBMISSION [X

YES (Ifyes, complete 15. EXPECTED SUBMISSION DA TE)

NO DATE 04 29 2005 ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)

This Revision I to LER 2004-001 provides a status update to the investigation regarding three missing 18-inch fuel rod segments. Search efforts for the missing segments are continuing. A subsequent revision to this LER will be submitted when the investigation and causal analysis are completed.

I I

On June 23 through 25, 2004, Humboldt Bay Power Plant (HBPP) personnel identified documents containing conflicting information regarding the location of segments cut from a single fuel rod from spent fuel assembly A-49. One document indicated that the segments were placed in a shipping container and then returned to the spent fuel pool (SFP), while another document indicated the entire A-49 assembly was shipped to Nuclear Fuel Services, Inc., in West Valley, New York, for reprocessing.

The NRC was notified on July 16, 2004, pursuant to 10 CFR 20.2201(a)(1)(ii) and 10 CFR 50.72(b)(2)(xi). Reference NRC Event Notification 40877.

As of November 19, 2004, HBPP personnel have searched much of the SFP, but the segments have not been located. It is believed that the segments are either safely stored in the SFP or were shipped in a shielded cask to a facility licensed to accept radioactive material. Therefore, there is no undue risk to the health and safety of the public and licensed facility workers.

The apparent event cause is lack of attention to detail regarding documentation of fuel movements.

NRC FORMU 366 (6-2004)

PRINTED ON RECYCLED PAPER

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Plant Unit 3 TEXT I.

Plant Conditions

Humboldt Bay Power Plant (HBPP), Unit 3, was shut down in 1976, and has been maintained in SAFSTOR since 1988.

II.

Description of Problem A.

Background

During 2003, PG&E plant personnel initiated a complete review and cataloging of the contents of the Spent Fuel Pool (SFP) in preparation for the planned decommissioning of the plant, including the transfer of spent fuel into an onsite Independent Spent Fuel Storage Installation. As a result of the comprehensive documentation search and review conducted as part of the process, PG&E identified a discrepancy in plant records that calls into question the location of three 18-inch segments of a single spent fuel rod removed from assembly A-49 in 1968. Based on the review of available records and interviews with employees from this period that have been conducted to-date, there is no firm evidence the three segments were shipped offsite. However, as of November 19, 2004, the search of the SFP's storage containers, and all readily accessible SFP spaces, has not located the three segments.

B.

Event Description

On June 23, 2004, plant personnel identified Onsite Review Committee (OSRC) meeting minutes dated October 2, 1968, that describe cutting three 18-inch segments from one fuel rod located in spent fuel assembly A-49.

These segments were placed into a small container (1-1/2-inch diameter, schedule 40 pipe) in preparation for shipment to the Battelle Memorial Institute in Columbus, Ohio, for analysis. The meeting minutes further state that the shipment to Battelle was subsequently cancelled and the small container with the three 18-inch fuel rod segments was returned to the SFP.

The specific location of this container in the SFP was not identified.

Subsequent interviews with both the engineer who developed the plan used to perform the cuts of A-49 and the technician who performed the actual cuts support that the cuts were made but indicate that each segment may have been closer to 12 inches in length rather than the 18 inches in length specified in the OSRC meeting minutes.

On June 25, 2004, after further research, plant personnel found shipping records indicating that on August 7, 1969, the A-49 fuel assembly was

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(NFS) in West Valley, New York, for reprocessing. No mention was made in the shipping record that the A-49 assembly had been shipped with portions of one of it's rods left behind in the SFP. This potentially contradicts the October 2, 1968, OSRC meeting minutes. No records were found that indicated that the removed portions of the fuel rod were subsequently placed into the canister later used to ship the rest of A-49 to NFS.

Further review of records did not resolve the discrepancy, so on June 29, 2004, PG&E verbally notified the NRC Region IV of the discrepancy in records and the uncertainty regarding the specific location of the fuel rod segments removed from A-49. PG&E personnel developed a plan to search the SFP for the segments.

On July 7, 2004, PG&E began a physical search of the central storage container (CSC), a high probability location for the remnant portions of the A-49 rod, as well as the three 12 to 18-inch segments. On July 9-11, 2004, PG&E recovered several fuel rod fragments from the CSC, some of which PG&E originally believes are probably remnants from the cut A-49 rod.

However, the three 12 to 18-inch segments were not found in the CSC.

On July 16, 2004, HBPP notified the NRC of the potentially lost or missing licensed material in accordance with 10 CFR 20.2201(a)(1)(ii) and 10 CFR 50.72(b)(2)(xi) regarding a planned press release (NRC Event Notification 40877).

A total of 10 fuel fragments ranging in length from 2-1/2 inches to 11 inches (total length of the 10 fragments is approximately 50 inches) have been found in the CSC that appear to have cuts on one or both ends.

Independent analyses of these fragments were done in August and October 2004, with differing results. The earlier analysis, conducted by a PG&E metallurgist from the Diablo Canyon Power Plant, concluded that these segments had fractured, and not cut, ends. The latter analysis, conducted by two outside metallurgical experts and a fuels expert previously with General Electric, concluded just the opposite - that the fragments were cut and are quite possibly remnants from the cut A-49 fuel rod (original length 84 inches). All of the A-49 remnants may not be included in these fragments, because the procedure used for the cutting called for remnants held firm in the A-49 grid spacers after the cutting were to be left in A-49.

This issue is continuing to be researched, and the conclusions will be reported in Revision 2 to this LER.

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Plant Unit 3 TEXT From early July to November 19, 2004, PG&E continued with an expanded physical search of the SFP. All storage containers within the SFP have been emptied and reviewed, and all accessible spaces within the SFP have been searched with video probes. The three, approximately 12 to 18-inch, fuel rod segments have not yet been found.

In parallel with the search of the SFP, HBPP personnel continued their review of historical documents and interviewed former employees who were associated with SFP and radioactive waste operations at HBPP. In addition, HBPP personnel asked companies such as NFS and Battelle to review their records to determine if the three 12 to 18-inch-segments were received at their location. Though much information has been uncovered that sheds light on what transpired in 1968 and beyond that will be helpful in PG&E's search, to-date none of this information has definitively identified the location of the unaccounted for fuel segments.

The status of PG&E's investigation into the missing fuel rod segments was discussed in a public meeting in Eureka, California, on September 29, 2004.

The meeting was attended by representatives from the NRC and PG&E, the public, and the media.

10 CFR 20.2201 (b) requires a written report within 30 days after the initial notification for the occurrence of any lost, stolen, or missing licensed material that was reported under 10 CFR 20.2201 (a)(1 )(ii) for licensed material in a quantity greater than 10 times the quantity specified in Appendix C to Part 20. The written report must contain responses to six specific items listed in 10 CFR 20.2201 (b). The six items are identified below, along with PG&E's responses:

(i) A description of the licensed material involved, including kind, quantity.

and chemical and physical form Assembly A-49 was removed from the core in the fall of 1965. The amount of fuel in question consists of three approximately 1/2-inch-diameter by 18-inch-long segments, weighing a total of about 4 pounds, which were cut from a single, seven-foot fuel rod. The three segments come from a fuel rod that is clad in type 304 stainless steel. For purposes of analysis, PG&E conservatively assumes the segments were 18-inches long each, though interview evidence suggests they were probably shorter. Table I contains a detailed physical description, Table 2 contains the isotopic inventory of each missing fuel rod segment and total for the

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three segments, and Table 3 contains the estimated dose rate summary, unshielded, for each segment, assuming they were all 18 inches in length.

(ii) A description of the circumstances under which the loss or theft occurred According to the October 2, 1968, OSRC meeting minutes, the three approximately 18-inch segments from assembly A-49 were placed in a pipe for shipment to Battelle Memorial Institute in Columbus, Ohio, for analysis. The shipment was cancelled and the pipe containing the fuel segments was returned to the SFP. PG&E interviewed available OSRC members who attended this October 2, 1968 meeting, and they recall that the pipe with the fuel segments was placed in the SFP, and that a lanyard was used to attach the pipe to the SFP railing.

In 1968 HBPP received a license from the Atomic Energy Commission (AEC) to ship spent fuel to NFS for reprocessing in a water-filled (for cooling) cask designed to hold 18 fuel assemblies. The license specified coolant radioactivity limits and specified that failed fuel was to be encapsulated before placement into the cask and shipment.

Encapsulation was interpreted to mean that each failed fuel assembly was to be enclosed in its own container, and sealed by welding, an expensive process that HBPP and Battelle believed was unnecessary. Battelle's calculations showed that the coolant radioactivity limits could be met without failed fuel "encapsulation." HBPP submitted an application to the AEC for a license amendment that would allow it to ship failed spent fuel assemblies in special containers designed by Battelle laboratories that would be individually sealed (bolted lid, not welded) and loaded into the 18 fuel assembly shipping cask.

The AEC was reviewing the license amendment application when HBPP and Battelle decided to perform some experiments on segments of an actual fuel rod to provide additional evidence to the AEC that supported licensing of the Battelle canister. It is for this purpose that the A-49 fuel rod was cut and the three segments prepared for shipment to Battelle.

Though documentation has not been found that indicates why the experiment at Battelle was cancelled, both HBPP and Battelle records verify that the fuel segments were never sent to Battelle. In December of 1968 the AEC approved HBPP's license amendment to ship failed fuel to NFS in the Battelle-designed canister. The Battelle-designed canister was used for the NFS shipment in 1969 that contained assembly A-49.

Though no one interviewed recalled adding individual rods or segments to shipments of spent fuel assemblies and no records have been found

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Plant Unit 3 TEXT indicating that this took place, doing so would have been possible and consistent with the motivation behind the experiment for which the fuel rod was initially cut.

Between 1971 and 1974, HBPP made 11 shipments containing 66 fuel rods to General Electric's (GE) Vallecitos facility in Livermore, California, for analysis and final storage. PG&E allowed GE to remove fuel rods to assist GE in improving the design of the fuel they provided to plants using their reactor design. Though it is not likely the A-49 fuel rod segments were sent to GE (they would have rejected the receipt of any fuel rods not expected in a shipment), GE was requested to search their fuel receipt records to ensure they did not receive and store the unaccounted for A-49 fuel segments. PG&E has received the review results from GE, which indicate they did not receive or store the A-49 fuel segments. PG&E is presently reviewing the GE results to ensure they are complete.

From 1968 to 1986, HBPP made over 400 shipments of low-level radioactive waste (LLRW) to facilities licensed to receive such materials located in Beatty, Nevada; Richland, Washington; and Bamwell, South Carolina. The majority of these shipments did not contain material that was taken from the SFP.

In 1985, in preparation for entering SAFSTOR, plant personnel removed all items that were attached to the SFP railing. Each item was either shipped to the Barnwell LLRW facility or was returned to another location in the SFP. Recent visual observation has confirmed that no containers are currently attached to the SFP railing. No documentation has been found describing the movement of the three 18-inch segments in the container, hanging on the SFP railing, to any other location in the SFP.

Though PG&E's review of detailed LLRW shipping records is not yet complete, none of the shipping records indicate that the three 18-inch segments (or a 20-inch-long 1-1/2-inch-diameter pipe that could contain the segments) were sent to an LLRW offsite location.

No evidence has been uncovered to support the possibility of theft or diversion of the unaccounted for fuel segments. Due to the high radioactivity of the material, in order to be handled safely, the segments would have to be encased in a heavy-shielded container that would have to be moved with special handling equipment designed for this purpose, precluding an abrupt loss. Since plant startup, HBPP has been equipped with a system of radiation monitors for the refueling building (where the SFP is located), with alarm setpoints that are capable of alerting plant

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TEXT personnel of the movement of highly radioactive material should the fuel segments have been removed from the SFP without being in a shielded container. This could not have occurred casually without plant staff or security personnel observing the movement.

(iii) A statement of disposition. or probable disposition, of the licensed material involved Because the three approximately 18-inch segments are not readily identifiable in the SFP, the following probable dispositions exist: (a) the fuel segments are in the SFP but can no longer be uniquely identified, or are in a SFP area that is not readily accessible; (b) the fuel segments were shipped offsite to an appropriately controlled and restricted facility for either analysis or reprocessing, e.g., NFS or GE; (c) the fuel segments were inadvertently included in a shipment to a licensed, monitored, and restricted LLRW facility, e.g., Barnwell, SC, or Richland, WA.

(iv) Exposures of individuals to radiation, circumstances under which the exposures occurred, and the possible total effective dose equivalent to persons in unrestricted areas No specific exposures to plant personnel or the public have been identified as a result of this event. Table 3 contains the estimated dose rate summary, unshielded, for each segment, conservatively assumed to be 18-inches in length.

(v) Actions that have been taken, or will be taken, to recover the material PG&E has implemented an aggressive action plan with three major elements: (1) perform a detailed physical inspection of the SFP, (2) collect and perform document reviews onsite and at NFS, Battelle, and GE Vallcecitos, and (3) conduct interviews with present and former employees and contractors who have been associated with SFP and radioactive waste operations at HBPP.

(1) SFP Inspection - On July 7, 2004, plant personnel began a physical search of the SFP to locate the three 12 to 18-inch segmented fuel rods from assembly A-49, as well as any remnants of the rod. The pool, which is from 26 to 36-feet deep and 22-feet wide by 28-feet long, must be searched slowly and methodically, using underwater cameras and remote-controlled tools. There are 390 used fuel assemblies stored in the SFP, with

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8 OF Plant Unit 3 TEXT numerous spaces between and around them. In addition, there are six storage containers, five of which were filled with various irradiated hardware and components. The sixth storage container holds fuel rods from assembly UD-6N that was damaged in 1975. Each of these storage containers was emptied piece-by-piece to conduct a complete search for the fuel segments. These storage containers are approximately 8-feet long and range in dimension from approximately 4 to 7-inches square.

PG&E has completed its search of the readily accessible areas of the SFP. The following is a detailed account of the items and areas searched in the SFP.

1. Storage Containers 1 through 4

2. Central Storage Container (CSC)

3. Storage Container for UD-6N

4. All open spaces in the SFP

5. Accessible areas under the racks

6. On top of the fuel assemblies

7. All open cell locations

8. Visible areas under the energy absorber

9. Other storage cans in the SFP used to store irradiated hardware Search of these areas has not located the three 18-inch segments.

Additionally, PG&E has reviewed the video records taken earlier this year of each fuel assembly and the space under each fuel assembly (except for two assemblies, that cannot easily be moved). An examination of the fuel fragments found in the SFP indicate that it is quite possible that some of the fragments are from the A-49 fuel rod. This issue is continuing to be researched, and the conclusions will be reported in Revision 2 to this LER.

PG&E is planning to search non-readily accessible areas of the SFP to complete the full SFP search for the 12 to 18-inch fuel rod segments and other fuel fragments by early 2005. These areas are as follows:

1. SFP sump

2. In and under the SFP resin pile

3. Under the fuel racks using crawler-camera (2) Document Reviews - A document review was performed to determine the source of the fuel fragments that have been found in the SFP since November 2003, and to attempt to resolve the discrepancy between the October 2, 1968, OSRC meeting minutes and the conflicting shipping

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0 1 l-9 Plant Unit 3 TEXT record dated August 7, 1969, regarding the one rod in A-49. As of November 19, 2004, the documentation review has not resolved the discrepancy.

Additional documents continue to be reviewed onsite and offsite. PG&E requested NFS, Battelle, and GE Vallecitos to search their records. The status of these record searches is as follows: NFS stated that they could not locate any records pertaining to the A-49 shipment and available personnel do not recall a separate shipment. Battelle records indicate that the shipping cask they sent to HBPP for transport of the three 12 to 18-inch segments was received back at Battelle empty (as intended, since the experiment had been cancelled). PG&E has received the review results from GE, which indicate they did not receive or store the A-49 fuel segments. PG&E is presently reviewing the GE results to ensure they are complete. Upon completion of the document reviews and causal analysis, Revision 2 to this LER will be issued.

(3) Interview Personnel - PG&E interviewed available OSRC members who attended the October 2, 1968, meeting, and they provided useful information concerning the location of the three 12 to 18-inch fuel segments when they were initially returned to the SFP. PG&E has contacted other personnel believed to have been directly or indirectly involved with the A-49 activities, as well as other pool cleanup projects.

PG&E has also prepared a list of names of additional former employees and contractors who may have been associated with SFP and radioactive waste operations at HBPP. The results of personnel interviews will be included in Revision 2 to this LER.

(vi) Procedures or measures that have been, or will be. adopted to ensure against a recurrence of the loss or theft of licensed material Prior to the discovery of fuel fragments in the SFP in November 2003, the scope of the HBPP material control and accountability program only included fuel assemblies, not fuel fragments. Currently, PG&E is in the process of modifying the program to include the documentation and inventory of fuel fragments, segments, and any other portions of a fuel rod that are not contained in a complete fuel assembly. The results of the inventory reconciliation will be included in the final report for this event.

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Status of Inoperable Structures, Systems, or Components that Contributed to the Event Although assembly A-49 was originally selected for analysis partially based upon noted fuel damage, this selection did not materially affect the proper tracking of the three 18-inch fuel segments once they were removed. The location, identification, and possible disposition of all of the remnants of A-49 are made more difficult by the fuel cladding damage known to affect a portion of the subject A-49 rod.

D.

Other Systems or Secondary Functions Affected

None E.

Method of Discovery

On June 23 through 25, 2004, while in the process of reviewing records and verifying the contents of the SFP in preparation for loading materials into dry cask storage, PG&E personnel identified documents containing conflicting information regarding the location of segments cut from a single fuel rod from spent fuel assembly A-49. One document indicated that three approximately 18-inch segments were removed from one fuel rod, placed in a shipping container and then returned to the SFP, while another document indicated the entire A-49 assembly was shipped offsite to NFS for reprocessing.

F.

Operator Actions

None G.

Safety System Responses None Ill.

Cause of the Problem A.

Immediate (apparent) Cause Lack of attention to detail regarding documentation of the movement and location of fuel components, specifically A-49 fuel segments, stored in the SFP by various licensed plant personnel and supervised contract personnel. HBPP personnel, programs, and procedures for fuel

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20 TeaT component movements, during the 1968 to 1986 period, were not specific enough to ensure traceability of fuel segments once separated from an assembly.

B.

Root Cause A causal analysis is continuing and will be reported in Revision 2 to this LER.

IV.

Assessment of Safety Consequences

It is unlikely that the three 18-inch fuel segments were taken from HBPP in an unauthorized manner. HBPP has a system of radiation monitors inside and outside the refueling building (where the SFP is located) with alarm set points that are capable of alerting plant personnel of the movement of highly radioactive material. Due to the radioactive nature of the material, in order to be handled safely, the segments would have to be encased in a heavy-shielded container that would have to be moved with special handling equipment designed for this purpose, thereby precluding an abrupt loss. This could not have occurred without plant staff or security personnel observing the movement.

The administrative, radiological, and security barriers in-place at HBPP, add to the belief that the three 12 to 18-inch fuel segments either remain in a currently unsearched area of the SFP or were shipped offsite in an appropriate manner.

The fuel segments may have been shipped to an appropriately controlled and restricted facility such as NFS, Battelle, or GE Vallecitos for either analysis or reprocessing. This would have been done using a licensed shipping cask that was properly (safely) transported. If the fuel segments were inadvertently included in a shipment to a LLRW disposal site, the segments also would have been placed in a licensed shipping container that was properly (safely) transported to a licensed, restricted, and monitored storage facility.

Therefore, there is reasonable assurance that the public health and safety was not, and is not, adversely affected by this event.

Table 3 provides the estimated dose rates that would be encountered when handling the fuel segments outside of the SFP and not in a shielded cask.

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0 1 12 OF 15 Plant Unit 3 TEXT V.

Corrective Actions

A.

Immediate Corrective Actions

HBPP programs, procedures, and personnel training have been revised to require specific detail(s) regarding the documentation of location of fuel components as they are identified in the SFP. A full cataloging and characterization of the contents of the SFP is being performed to ensure a complete and accurate accounting of all SNM in PG&E's possession at HBPP, down to the fragment level.

B.

Corrective Actions to Prevent Recurrence Additional cause investigations will be performed, and any further actions identified will be reported in a supplement to this report.

VI.

Additional Information

A.

Failed Components None B.

Previous Similar Events

None

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0 1 13 OF 15 Plant Unit 3 TEXT TABLE 1 DESCRIPTION OF 18-INCH SEGMENTS FROM A-49 Type of Special Nuclear Material Spent Fuel Rods, GE Bundle Material Uranium Dioxide, initially enriched to 2.578 percent, encased in 304 stainless steel cladding Physical Form Solid Each Fuel Segment Total of three Fuel from A-49 Segments Length of Spent Fuel Rod Segments 18 inches 54 inches Spent Fuel Rod Diameter 0.420 inches OD fuel Same 0.423 inches ID rod 0.464 inches OD rod Burnup MWD/IMT 12,980 MWD/MTU Same Weight of Special Nuclear Material 4.7 grams 14.1 grams Note: Weights and activities presented in this table have been developed for the year 2004.

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Plant Unit 3 TEXT TABLE 2 ISOTOPIC INVENTORY OF THE THREE 18-INCH SEGMENTS FROM A-49 Nuclide Each 18-inch Se ment Total of three 18-inch Segments Mass (grams)

Activity Mass (grams)

Activity (Curies)

(Curies)

U-235 1.37E+00 2.97E-06 4.11 E+00 8.91 E-06 U-238 3.62E+02 1.22E-04 1.09E+03 3.66E-04 Pu-239 1.86E+00 1.15E-01 5.58E+00 3.45E-01 Pu-240 9.83E-01 2.23E-01 2.95E+00 6.69E-01 Pu-241 9.41 E-02 9.74E+00 2.82E-01 2.92E+01 Pu-242 3.51 E-01 1.39E-03 1.05+00 4.17E-03 Am-241 5.16E-01 1.77E+00 1.55E+00 5.31 E+00 Cm-242 5.24E-07 1.73E-03 1.57E-06 5.19E-03 Sr-90 8.42E-02 1.19E+01 2.53E-01 3.57E-01 Cs-1 37 2.29E-01 2.OOE+01 6.87E-01 6.00E+01 Co-60 2.30E-06 2.60E-03 6.90E-06 7.80E-03 Ni-63 8.02E-03 4.55E-01 2.41 E-02 1.37E+00 Ni-59 5.07E-02 4.1 OE-03 1.52E-01 1.23E-02 Nb-94 2.33E-07 4.36E-08 6.99E-07 1.31 E-07 Tc-99 3.41 E-01 5.84E-03 1.02E+00 1.75E-02 1-129 8.41 E-02 1.49E-05 2.52E-01 4.47E-05 Notes:

1. Weights and activities presented in this table have been corrected for the year 2004.

2. The isotopic inventory for the 18-inch fuel rod piece was calculated by ORIGEN

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0 1 15 OF 15 Plant Unit 3 TEXT TABLE 3 ESTIMATED DOSE RATE SUMMARY - UNSHIELDED OF ONE 18-INCH SEGMENTS FROM A-49 Each 18-inch Fuel Rod Segrment (radlhr in air)

Years of Dose Rate on Dose Rate at 1 ft Dose Rate at 3 ft Decay*

Contact 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> 1.94E+06 2.79E+04 3.66E+03 1

9.25E+04 1.31 E+03 1.71 E+02 2

5.25E+04 7.38E+02 9.67E+01 5

2.24E+04 3.05E+02 4.OOE+01 10 1.1 5E+04 1.55E+02 2.03E+01 15 8.68E+03 1.1 7E+02 1.54E+01 20 7.37E+03 9.97E+01 1.30E+01 25 6.44E+03 8.72E+01 1.14E+01 35 5.03E+03 6.81 E+01 8.91 E+00 50 3.52E+03 4.77E+01 6.24E+00

• The A-49 assembly was removed from the core during the fall of 1965 refueling outage that began September 20, 1965.

Note:

The calculated dose rates in air at contact (25 years of decay) are 16 to 35 times higher than those recently measured in water (approximately at contact for fuel fragments in the HBPP SFP). The reasons for these differences are a combination of the following:

• The calculated dose rates in air include radiation contributions along the entire 18-inch fuel rod segment. Water reduces the contribution from axial locations above and below the measurement point.

• The calculated value is a true contact reading on the SNM, whereas the measured value is about 1-inch from the active fuel due to the size of the GM tube and the fuel rod cladding.

• Conservatisms are included in the calculated value.