ML20056C871
| ML20056C871 | |
| Person / Time | |
|---|---|
| Site: | Framatome ANP Richland |
| Issue date: | 07/07/1993 |
| From: | Bocanegra R, Hooker C, Reese J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML20056C870 | List: |
| References | |
| 70-1257-93-07, 70-1257-93-7, NUDOCS 9307260055 | |
| Download: ML20056C871 (9) | |
Text
[..
U.S. NUCLEAR REGULATORY COMMISSION REGION V Report No. 70-1257/93-07 Docket No. 70-1257 License No. SNM-1227 Licensee:
Siemens Power Corporation 2101 Horn Rapids Road Richland, Washington 99352-0130 Facility Name: Siemens Power Corporation Inspection at: Richland, Washington Inspection Conducted: June 14-18, 1993 ci U
Inspectors:
i C.
Hooker, Fu a lities Inspector Date Signed:
/
7h43 anegra,Radiat[onSpecialist Date' Signed
. Klaaky, Nuclea icality Safety Specialist, licensing
- Branch, 1 C cle and Safeguards Division NMSS Approved by:
/
7/7/93 Jamp( ll. Reese,' Chief.
Date $igned tilYties Radiological Protection Branch i
Summary:
Areas inspected: This was a routine inspection of environmental protection, radioactive waste management, onsite followup of licensee events, and followup on open items.
Inspection procedures 30703, 93702, 92701, 88015, 88020, 88035, and 88045 were addressed.
Results: Within the scope of this inspection, no violations or deviations were identified.
.9307260055 930707 PDR' ADOCK 07001257' C
PDR m
l-DETAILS 1.0 Persons Contacted 1.1 Siemens Power Corporation (SPC)
B. N. Femreite, Plant Manager,
- R. E. Vaughan, Manager, Safety, Security and Licensing
- R. L. Feuerbacher, Manager, Plant Operations M. K. Valentine, Manager, Manufacturing Engineering
- L. J. Maas, Manager, Regulatory Compliance
- J. B. Edgar, Staff Engineer, Licensing
- S. S. Koegler, Manager, Waste Management Engineering
- J. A. Shurts, Manager Materials and Scheduling
- L. D. Weaver, Supervisor, Traffic and Warehousing J. H. Phillips, General Supervisor, Chemical Operations T. C. Probasco, Safety Supervisor
- K. Tanaka, Environmental Engineer M. S. Stricker, Waste Management Engineer
- C. D. Manning, Criticality Safety Specialist
- R.
K. Burklin. Health Physicist
- D. L. Belt, Radiation Safety Specialist
- E. J. Hough, Technical Training Specialist 1.2 NRC Personnel C. N. Smith, Chief, Operations Branch, Fuel Cycle and Safeguards Division, NMSS
- Denotes those attending the open exit interview on June 18, 1993.
In addition to the individuals noted above, the inspectors met and held discussions with other members of the licensee's staff.
In the following sections of this report, the singular use of the word
" inspector" indicates that only one inspector was involved in the specific area and the plural use indicates that more that one inspector shared involvement in the specific area.
2.0 Onsite Review of Licensee Events (93702, 88015 and 88020)
Incinerator - Event No. 25458 The inspecticn of this event was to review the history of incinerator operations, and to verify that the licensee was taking appropriate actions to identify the cause of the event. The information provided in this Section provides a brief non-technical history of incinerator operations and actions being taken by the licensee.
On April 28, 1993, the licensee reported to the NRC Operations Officer that the U-235 criticality safety mass control limit had been exceeded L
P
,u m
4 2
t 1
in.the-incinerator which burns uranium bearing combustible waste. The report was made in accordante with the NRC Bulletin 91-01, reporting l
requirements, a
In response to NRC concerns related to:this event, by letter dated May 5, 1993, to the NRC, the' licensee agreed to not restart the incinerator-without the NRC's' review and approval of a revised criticality control-plan. By letter dated May 10, 1993, to'the NRC, the licensee provided.
followup report that provided a summary of the their assessment of the:
event and corrective actions taken.
During the onsite inspection, the inspector. discussed the event and details of the licensee's investigation with' cognizant licensee a
personnel, reviewed selected records related to the event, and performed a walk-down of the incineration system. Details of the licensee's; report, No. 25458 dated May-10, 1993, were' discussed with the licensee during the onsite inspection.
2.1 Criticality Safety Analysis (CSA)
On May 12, 1987, a process engineer.. submitted' a Criticality Safety l
Evaluation Request to the Criticality Safety Component (CSC) for.a CSA of the Solid Waste Uranium Recovery (SWUR) incineration facility.
The-request provided a summary of the waste handling operations,. and the incineration equipment and process. By. letter dated August 4, 1987,:to:.
the process engineer, the CSC stated that criticality safety of'the SWUR-facility may be assured by the use of existing analysesifor. 55-gallon waste: drums (CSA U-16.15) and safe batch work stations. (CSA. GEN-1.0). '
CSA GEN 1.0, " Safe Batch Work Stations," dated October 28, 1985,iwas a generic CSA that: covered safe batch containers and work stations which-were limited to not more than 4556cf a minimum critical mass 'at the enrichment of the contents.
2.2 Operations The majority of LEU combustible and non-comb' ustible waste is generated
~
a Building. LEU contaminated waste is also from operations within the UO2 generated at other onsite locations. The waste is collected in'55-gallon drums and sent to the Solid Waste Uranium Recovery (SWUR) 1 facility where the waste -is inspected, sorted, and segregated into combustible'and non-combustible waste for volume reduction and uranium.
1 recovery. The ash from the incineration process Lis1 stored in 35' gallon 1l drums for future ' uranium recovery. Although pilot. operations fo'r.
J
~
recovery.of the uranium from the ash;have been. completed, the licensee has not constructed 'a facility:to process'the'large volume of-ash generated by incineration. 'Non-combustible waste is packaged in reusable drums' for ultimate radioactive waste disposal. During normal.
June -1993, approximately 109,000 cubic' feet of combustible waste.has
- l operations, about 600 drums per month are processed-through SWUR. As of been processed through the incinerator.
All. drums of. waste-sent:to the' SWUR facility are assayed using' a nondestructive. assay -(NDA) system.:
j The NDA systems consist of lead shielded chambers equipped with a.
j q
5
-=
3 rotating platform where drums 'or other waste containers are placed and rotated, while being-assayed using a sodium iodide (Nal) gamma counting system that measures the U-235 content of each drum.
The incineration process is divided into four systems:
(1) feed preparation, (2) incineration, (3) off-gas treatment, and (4) ash ~
removal. The contents of pre-assayed drums of unsorted waste are dumped onto a rotating table in a glove box enclosure where the material is inspected, sorted and segregated by operators. Non-combustible waste is repackage into 55-gallon drums, assayed and transferred to designated outside storage areas for ultimate off-site disposal or future reprocessing for uranium recovery. Combustible waste is compacted in 3.5 cubic-foot cardboard boxes, sealed and bar coded for'the computerized (PC) automated incinerating process. The boxes are placed on an elevator where the bar code is read and entered into the box assay PC system. The boxes are transferred to a weighing station.where the weight of each box is automatically entered into the box assay PC system. After the box has been weighed, it is transferred to a queuing station. At the queuing-station the bar code is automatically read again for box identification and expected sequence.
Each box is automatically inserted into a lead shielded assay chamber equipped with three Nal detectors, rotated at 5 revolutions per minute and counted for 100 seconds for its U-235 content. The data from the box assay PC system (bar code number, weight and U-235'value) is sent to a main control PC for storage and computation of burn time.
The box is automatically. transferred from the.NDA chamber to an in'cinerator queuing station for burning. The box assay system automatically-performs a calibration test hourly with two standards (8 gram and 24 gram internally mounted standards for each detector).
During routine operations, the system performs.a background count for 100 seconds,-
counts a box for 100 seconds, removes the box, and rechecks.the counting-system with the 24 gram standard and sends the assay data to the main-computer. Failure of 24 gram source check discontinues operation and the box has to be manually removed from the assay chamber and a calibration check using the 8 gram and 24 gram standards is performed.
If the calibration check fails, plant engineering must be notified.
The assayed cardboard boxes are automatically fed through a sealed guillotine door into the primary burn chamber. The automated system can feed two boxes at a time into the incinerator. However, normal operations consists of feeding and incinerating one box at a time.
Combustion products and other constituents generated from burned materials are passed to a secondary chamber with a much higher temperature to completely burn all combustible gases.
Both chambers are lined with a high density refractory to minimize permeation of uranium.
Off-gas (particulates, vapors, and gases from burned materials) from the secondary chamber is processed through a scrubbing / treatment system for cooling and removal of acid gases and particulates. Uranium bearing' ash in the primary chamber is pushed along the burn hearth by:the incoming feed (boxes of waste). The ash pushed from hearth drops:to a lower i
section the primary chamber where the material is allowed to burn down.
The box assay PC system is programmed to lockout and stop.the automatic L
i
p, z-.
- 1 4
feeding of waste boxes to the incinerator at 90%'(about 715 grams U-235) of the incinerator's programmed mass limit of 15.9 kgU. (793 gramsLU-235 assuming an enrichment of 5.0 wt.% U-235). When the lockout occurs, as much ash as possible is pushed from the incinerator and collected in 35-gallon drums. Each drum is weighed, tumbled, and sampled to verify its uranium content (chemical analysis)' and enrichment (mass. spectrometry).
When the last drum has been removed from the ash drop hood, the box assay PC system is reset for another burn cycle.
It takes the laboratory about 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to prep and complete the analysis of. ash samples.
Incineration of LEU combustible waste commenced in August 1988.
Initial operations of the safe batch control of the-incinerator was based on the sum of the feed material assays minus the sum of the ash removal assays.
This accounting system was maintained on a main computerized.
accountability system for the facility.
Inputs to the main computer system were (1) data from the box assay PC system, (2) the percent uranium from daily samples of the liquid discharged from the scrubber system, (3) assay data from removed ash, and (4) NDA measurements of liEPA filters when they were changed.
In February 1989, after the first six months of operation with four runs of incinerating LEU waste completed (total of about 14 drums of uranium contaminated ash generated), the licensee established a committee to review the operation of the. SWUR facility. The Committee determined that the main computer system showed a negative balance of about 447 grams U-235 in the incinerator. The exact reason was not fully understood, but speculation centered around the computer' system. A detailed review of the computer system and material balance program was recommended. The Committee recommended that the review should address-the controls on programs and. data used in assuring criticality safety as well as improvements to the incinerator system material balance. The committee noted that confusing and inconsistent bases were being used:
"The result from the box assay is effectively the estimated contained grams U-235. This value is converted to grams U, based on an assumed 3.0 enrichment, for comparison to the waste barrel assay values and sent to the main computer where, presumably, it is converted to grams V, based on a 5.0% enrichment for criticality control. The system inventory was expressed as kg of 5.0% enriched uranium rather than as grams U-235.
Mass units are inconsistent with mixtures of pounds, kilograms,.
and grams being used."
Following changes to the accountability system, the licensee continued to experience accountability problems associated with the incinerator.
In November 1989, Plant Operations sent a memo to the Criticality Safety Component requesting a CSA for the SWUR incinerator, which was necessitated by Operations inability to run the ' incinerator in the manner for which it was designed at the current safe batch criticality.
L
e 4
5 control limit.
A Monthly Report for December 1989, from the Criticality Safety Component, stated that a CSA had been prepared to justify-an increase in the allowable U-235 inventory of the incinerator from about 800' grams to 1200 grams. However, a review of recent material balance data indicated that improvements (procedures, computer programs, etc.) were required before implementation of a higher limit. The CSA was never issued.
The licensee stated that in January 1990, the use of.the on-line balance was replaced by the use of a fixed heel (residual uranium bearing material from ash removal operations following burn campaigns) accounting system to control the safe batch limit of the incinerator.
The computer system added the assay value from each box of waste to an assumed programmed heel of ash. The assumed heel used was based on the uranium content of residual ash cleaned from the incinerator during previous operations. The assumed heel fluctuated with the uranium content of incinerated waste.
The incinerator was shut down in October 1992, for repairs and replacement of the quench column and other equipment in the off-gas treatment system. The HEPA filtering system was also replaced.
Prior to the shutdown of.the incinerator, the Criticality Safety Specialist (CSS) made arrangement for a routine six-month complete clean-out of the incinerator due to concerns with. slag buildup in the secondary chamber.
Normally no ash was observed in the secondary chamber during incinerator clean-outs. However, there was a continual buildup of tightly bonded slag on the inside surfaces of the chamber.
In late January 1993, the incinerator's secondary chamber was opened for a clean out. Although no ash was observed, the licensee observed more than normal buildup of slag on the inside surfaces of the chamber. The slag.was removed (chipped out) and placed in 35 gallon drums, inspected by the criticality safety specialist, tumbled and sampled for uranium content.
In'early February 1993, the sample results indicated that the slag contained about 230 grams of U-235.
Although the repairs and replacement of like equipment did not require a Start-up Council review, SPC's management directed such a review of the incinerator operations prior to' restart. This decision was based on (1) 4 NRC concerns'related to the lack of management controls of SPC's.
criticality safety program, (2) the licensee's review of operations relative to their Criticality Safety Analysis Update Program,' and (3) outstanding action items that needed to be completed prior-to restart.
During a Start-up Council meeting on March 29, 1993, the Criticality Safety Specialist discussed the need for criticality safety requirement changes from previous operations and a complete clean out of the incinerator. The changes were to incorporate an accurate mass in and mass out balance of the incinerator. A letter dated April 12, 1993-1 from a member of plant engineering to the CSS described a proposed method for tracking the U-235 in the incinerator.
J I
b I
6 The clean-out of the incinerator was completed on April 24, 1993. The removed ash was sampled and analyzed for uranium content. On April 27, 1993, the sample results were completed.
Based on a review of the sample results of the material cleaned from the incinerator and the analysis of the ash removed from the last burn run, the ' licensee determined that the safe mass limit (793 grams U-235 at an enrichment of-5.0%) of the incinerator had been exceeded by a factor of 1.6 i
(approximately 1650 grams U-235) based on-the enrichment (about 3.25 wt.% U-235) of the uranium contained in the ash and slag. The licensee.
reported this finding to the NRC on April 28, 1993.
2.3 Licensee's Investigation Based on discussions with cognizant licensee personnel, the review of selected licensee records, and facility tours,'it appeared that the licensee was conducting an in-depth and thorough investigation to-determine the cause of the event. The licensee's final investigation report and causes that led to the event will be reviewed in a subsequent inspection. This matter is considered as -an inspection followup item (70-17.57/93-07-01).
3.0 Inspection Followup Items (92701) 70-1257/93-03-07 (0 pen) CSA Update Program:
The status of the licensee's CSA Update Program was reviewed and discussed with cognizant licensee representatives. The review verified that the licensee was on schedule for the completion of Phase IB by-June 30, 1993, which included:
(1)
Validation of assumptions, equipment locations, and listed accident conditions of existing CSAs by Plant Engineering.
(2)
Review of Engineering validations for NRC Bulletin 91-01 reporting and license requirements.
(3)
Sort reviewed CSAs into three categories:
Category I CSAs that need urgent reanalysis due to unfounded assumptions or 1
incomplete accident analysis.
Category 11 CSAs that have some deficiencies, but can be corrected by addenda for an interim period.
Categor_y III i
CSAs that are adequate and will be not be revised as part of the update program.
b
w a
7 Phase 2 of the update program will commence in July 1593. This Phase includes reanalysis of Category -1 CSAs that will ~ be prioritized by the potential ~ safety impact and operational requirements. The licensee anticipates that this-phase will take about.seven months to complete.
Some of the elements in Phase 2 are: (1) verification of; systems with facility drawings and. design features, (2) establishment of ' integrated credible accident scenarios for systems grouped into one CSA, (3) complete a CSA for each _ integrated system, second party reviews will.
validate layout configurations, dimensions, assump(tions and. credible 4) incor accident scenarios for each system grouping, and limits and controls into operating procedures.
Selected Plant Engineering reviews performed to validate assumptions in existing CSAs for Phase 1 were examined. Of the reviews examined, no i
concerns were identified to indicate that the licensee's update plan was not being effective in^ identifying deficiencies in existing CSAs. The licensee's update program will be continually reviewed until its completion.
4.0 Radioactive Waste Management (88035)
The inspector evaluated the licensee's Radioactive Waste Management Program to determine if the licensee was complying with applicable NRC regulations and license requirements. The inspector reviewed selected records, procedures, and other documents, and additionally toured the facilities and interviewed personnel.
i-The records reviewed by the inspector did not reveal any instance where 10 CFR 20 release limits were exceeded. The inspector also determined that license effluent reporting requirements had been met. The inspector also verified that corrective actions for previously
[
identified problems with plugged sample flow lines were effective-in preventing reoccurrence. Flow measuring devices. observed by the inspector were operational and had current calibration stickers attached.
The inspector verified that radioactive waste stored on-site was properly accounted for, and inspections and surveys required by the license were being performed. The inspector noted that due to the large inventory of stored waste drums (approximately-14,000), it was difficult for the licensee to perform the periodic inspections and surveys in an effective manner.
Licensee representatives acknowledged the inspector's observation and stated that they expected their new: Waste Management Engineering Plan to correct the problem by reducing the inventory.
The Waste Management Engineering Plan (currently in draft) was developed due to planned facility expansions, more stringent environmental regulations, and reduction of generated and stored waste.
Individual tasks have been identified and assigned to engineers covering 'the period
. Fiscal Year 1994 (FY94) through FY96. The inspector reviewed a draft of the plan and interviewed personnel responsible for implementation, and-f noted that management support and commitment was evident.
E
7 8
Implementation of the Waste Management Engineering plan will be closely monitored during the routine inspection program.
5.0 Environmental Protection (88045)
The inspector assessed the licensee's environmental program to determine that the licensee was implementing its license commitments, and that inspector also evaluated the program to determine if the licensee _'s sampling methods and analysis procedures were consistent with industry standards.
The inspector reviewed a sampling of pertinent procedures, reports, and other documents, and toured the sampling stations identified in the license. The environmental monitoring program was documented'in written procedures and the required monthly audit of portions of the environmental program was being performed. The inspector verified that sampling devices were in place and functional, and discussed sampling methods with licensee personnel. The inspector reviewed selected analytical methods used to analyzed the environmental samples and did not identify any concerns. The inspector also verified that required samples were collected and analyzed and that Lower Level of Detection
~
(LLD) values stated in the license were being met.
The inspector'noted that-the licensee recently set up an environmental thermoluminescent dosimetry (TLD) network around the perimeter of the facility. The inspector performed confirmatory surveys around the perimeter fence using an NRC Eberline.PRM-7, S/N 10839, micro-R meter due for calibration on October 1,1993, to verify that exposure readings were within regulatory limits.
The inspector concluded that the licensee's environmental monitoring program was conducted in accordance with their license and met its safety objectives.
6.0 Inspection Exit Meetino (30703)
The scope and results of the inspection were summarized with the licensee representatives denoted in Section 1 on June 18, 1993, at the conclusion of the onsite inspection.
The licensee was informed that no violations or deviations were identi fied. The licensee was also informed that the incinerator event, described in Section 2.0, would be subject for further NRC review following the completion of the licensee's investigation, b