ML102660345
| ML102660345 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 10/25/2010 |
| From: | Lyon C Plant Licensing Branch IV |
| To: | Reddeman M Energy Northwest |
| Lyon C Fred, NRR/DORL/LPL4, 301-415-2296 | |
| References | |
| TAC ME3863 | |
| Download: ML102660345 (16) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 October 25, 2010 Mr. Mark E. Reddeman Chief Executive Officer Energy Northwest P.O. Box 968 (Mail Drop 1023)
Richland, WA 99352-0968 SUB,JECT:
COLUMBIA GENERATING STATION -ISSUANCE OF AMENDMENT RE:
CHANGE TO FINAL SAFETY ANALYSIS REPORT FOR U.S. DEPARTMENT OF ENERGY 618-11 HIGH-LEVEL WASTE BURIAL GROUND REMEDIATION (TAC NO. ME3863)
Dear Mr. Reddeman:
The U.S. Nuclear Regulatory Commission (NRC) has issued the enclosed Amendment No. 217 to Facility Operating License No. NPF-21 for the Columbia Generating Station. The amendment consists of changes to the licensing basis as described in the Final Safety Analysis Report (FSAR) in response to your application dated April 28, 2010, as supplemented by letter dated August 9, 2010.
The amendment revises the FSAR to reflect U.S. Department of Energy non-intrusive surveillance and characterization activities within the 618-11 High-Level Waste Burial Ground.
Your application also requested related changes to the Emergency Plan. The NRC staff's determination regarding the proposed changes to the Emergency Plan will be provided by separate correspondence.
A copy of the related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commission's next biweekly Federal Register notice.
Sincerely, Carl F. Lyon, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-397
Enclosures:
- 1. Amendment No. 217 to NPF-21
- 2. Safety Evaluation cc w/encls: Distribution via Listserv
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 ENERGY NORTHWEST DOCKET NO. 50-397 COLUMBIA GENERATING STATION AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 217 License No. NPF-21
- 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Energy Northwest (licensee), dated April 28, 2010, as supplemented by letter dated August 9, 2010, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) and the Commission's regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D.
The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
- 2
- 2.
Accordingly, the license is amended by changes to the Final Safety Analysis Report as indicated in the attachment to this license amendment, and Paragraph 2.C.(2) of Facility Operating License No. NPF-21 is hereby amended to read as follows:
(2)
Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A, as revised through Amendment No. 217 and the Environmental Protection Plan contained in Appendix B, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
- 3.
The license amendment is effective as of its date of issuance and shall be implemented within 60 days from the date of issuance. In addition, the licensee shall include the revised information in the Final Safety Analysis Report submitted to the NRC, pursuant to 10 CFR 50.71(e), as described in the licensee's application dated April 28, 2010, as supplemented by letter dated August 9, 2010, and evaluated in the staff's safety evaluation for this amendment.
FOR THE NUCLEAR REGULATORY COMMISSION Michael T. Markley, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to the Facility Operating License No. NPF-21 Date of Issuance:
October 25, 2010
ATTACHMENT TO LICENSE AMENDMENT NO. 217 FACILITY OPERATING LICENSE NO. NPF-21 DOCKET NO. 50-397 Replace the following page of the Facility Operating License No. NPF-21 with the attached revised page.
Facility Operating License REMOVE INSERT -3
- 3 (3)
Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use at any time any byproduct, source and special nuclear material as sealed neutron sources for reactor startup, sealed sources for reactor instrumentation and radiation monitoring equipment calibration, and as fission detectors in amounts as required; (4)
Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use in amounts as required any byproduct, source of special nuclear material without restriction to chemical or physical form, for sample analysis or instrument calibration or associated with radioactive apparatus or components; and (5)
Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to possess, but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.
(6)
Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to store byproduct, source and special nuclear materials not intended for use at Columbia Generating Station. The materials shall be no more than 9 sealed neutron radiation sources designed for insertion into pressurized water reactors and no more than 40 sealed beta radiation sources designed for use in area radiation monitors. The total inventory shall not exceed 24 microcuries of strontium-90, 20 microcuries of uranium-235, 30 curies of plutonium-238, and 3 curies of americium-241.
C.
This license shall be deemed to contain and is subject to the conditions specified in the Commission's regulations set forth in 10 CFR Chapter I and is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:
(1)
Maximum Power Level The licensee is authorized to operate the facility at reactor core power levels not in excess of full power (3486 megawatts thermal). Items in shall be completed as specified. Attachment 1 is hereby incorporated into this license.
(2)
Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A, as revised through Amendment No. 217 and the Environmental Protection Plan contained in Appendix S, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
(a)
For Surveillance Requirements (SRs) not previously performed by existing SRs or other plant tests, the requirement will be considered met on the implementation date and the next required test will be at the interval specified in the Technical Specifications as revised in Amendment No. 149.
Amendment No. 217
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 217 TO FACILITY OPERATING LICENSE NO. NPF-21 ENERGY NORTHWEST COLUMBIA GENERATING STATION DOCKET NO. 50-397
1.0 INTRODUCTION
By application dated April 28, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101250340), as supplemented by letter dated August 9, 2010 (ADAMS Accession No. ML102300537), Energy Northwest (EN, the licensee) requested changes to the Facility Operating License No. NPF-21 for the Columbia Generating Station (CGS). The requested change would revise the licensing basis as described in the Final Safety Analysis Report (FSAR) to reflect U.S. Department of Energy (DOE) non-intrusive surveillance and characterization activities within the 618-11 High-Level Waste Burial Ground (618-11).
The licensee also requested related changes to the Emergency Plan. The U.S. Nuclear Regulatory Commission (NRC) staff's determination regarding the proposed changes to the Emergency Plan will be provided by separate correspondence.
The supplemental letter dated August 9, 2010, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the staffs original proposed no significant hazards consideration determination as published in the Federal Register on June 29, 2010 (75 FR 37473).
The licensee proposed changes to the CGS FSAR to reflect the intentions of DOE through its contractor, Washington Closure Hanford (WCH), to perform non-intrusive surveillance and characterization activities within the 618-11 site. DOE intends to remediate the 618-11 site, among others at the Hanford Site. The non-intrusive characterization and surveillance activities are also called Phase 1 of the total 618-11 remediation project. This site is an 8-acre parcel located directly adjacent to land leased from the DOE by EN and is wholly within CGS's exclusion area. The site contains low-to-high-activity waste, fission products, some plutonium contaminated waste, and toxicological waste (bounded by beryllium). The DOE non-intrusive surveillance and characterization activities will obtain data and information necessary for planning future intrusive activities and remediation strategies (also called Phase 2 and Phase 3, respectively, of the total 618-11 remediation project).
- 2 Specifically, the proposed changes would modify the FSAR to discuss the non-intrusive surveillance and characterization activities at the 618-11 site, to delineate DOE authority and control for the non-intrusive activities, including lead responsibility for abnormal events at the 618-11 site, to summarize the potential hazards, and to describe the design-basis event (DBE) and its impact to CGS.
1.1 Background
As stated by the licensee in its application dated April 28, 2010, the 618-11 site is located 1100 ft west of the CGS Reactor Building, adjacent to property leased by EN from the DOE, and is entirely within CGS's exclusion area and security barrier. The site is approximately 375 feet north-to-south by 1,000 feet east-to-west and consists of 3 slope sided trenches, 50 vertical pipe units (VPUs), and 3 to 5 large caissons. The trenches are 900-foot long by 50-foot wide and 25 foot deep. The 50 VPUs are 22-inch diameter, 15-foot-long waste receptacles constructed by welding five 55-gallon bottomless drums together and burying them vertically with approximately 1a-foot spacing between the units. The units are open to the soil at the bottom. The large diameter caissons are constructed of 8-foot diameter corrugated metal pipe, 1a-foot long, with the top of the caissons being 15 feet below grade and connected to the surface by an offset 36 inch diameter pipe with a domed cap lid. These units were buried with approximately 15 feet of space between them. The caisson bottoms are open to the soil. The number of caissons is uncertain due to discrepancies in site documentation.
The 618-11 site has a number of aliases, including Wye Burial Ground, "yn Burial Ground, 300 Wye Burial Ground, and 318-11. This site received low-to-high-activity radioactive waste from the Hanford 300 Area laboratories and fuels development facilities from March 1962 to December 1967. The waste includes fission products, byproduct material (thorium and uranium), plutonium, and numerous known or suspected toxicologically hazardous materials.
Low-to-moderate-activity dry solid wastes were disposed in the trenches and moderate-to-high activity wastes were disposed in the VPUs and caissons. The estimated radionuclide inventory at the site is 1,000 curies (Ci) of strontium (Sr)-90, 1000 Ci of cesium (Cs)-137, and 10 kilograms (622 Ci) of plutonium (Pu)-239, and the estimated non-radiological hazardous material inventory is 91.4 kilograms of beryllium per caisson. These inventories are based on available information and are bounding for the purposes of hazard categorization and determination of potential radiological and toxicological dose consequences.
The 618-11 site was permanently closed on December 31,1967. Final site closure occurred in 1968 and the burial ground was covered with a minimum of 2 feet of soil. All metal storage units that were used are capped with a concrete plug. Perimeter concrete posts fitted with stamped brass radiation hazard markers were installed. Due to unauthorized entries and contamination spread by plants and wind, the site was enclosed with an 8-foot chain-link fence in 1974. The site continued to be plagued by plant and wind erosion contamination problems, which led to a final stabilization effort completed in 1982. An additional 2 feet of topsoil was added and seeded with crested wheat grass. Subsequent surveys indicate the soil overburden is intact with no detectable radiation levels above background, and the crested wheat grass has adapted well.
- 3 1.2 DOE Schedule The Atomic Energy Act of 1954, as amended, Chapter 9, Section 91, gives DOE the authority to provide for safe storage, processing, transportation, and disposal of hazardous waste (including radioactive waste) resulting from nuclear materials production, weapons production, and surveillance programs. DOE is responsible for assuring that efforts under this authority are compliant with the regulations set forth in 10 CFR Chapter III.
As stated by the licensee in its application dated April 28, 2010, the Hanford Federal Facility Agreement and Consent Order, or Tri-Party Agreement, between the DOE, U.S. Environmental Protection Agency (EPA), and the State of Washington Department of Ecology is the legal document that binds DOE to actions to comply with the Resource Conservation and Recovery Act (RCRA), the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), and the State of Washington Hazardous Waste Management Act (HWMA) (see References 4 through 7 of the Enclosure to the licensee's application dated April 28, 2010).
This agreement:
Defines and ranks CERCLA and RCRA cleanup commitments.
Establishes responsibilities.
Provides a basis for budgeting.
Reflects a concerted goal of achieving full regulatory compliance and remediation, with enforceable milestones.
The milestones represent the actions necessary to ensure acceptable progress toward Hanford Site compliance with RCRA, CERCLA, and HWMA. The schedule for the proposed 618-11 site non-intrusive surveillance and characterization activity is from February 2011 through February 2012 in order to support the final remediation milestone on or before September 2018.
The DOE has requested EN provide a notice to proceed by December 29,2010, to facilitate mobilization at the 618-11 site.
2.0 REGULATORY EVALUATION
The NRC staff applied the following regulatory requirements in its review.
Section 100.3, "Definitions," of 10 CFR Part 100, "Reactor Site Criteria," state, in part, that, Exclusion area means that area surrounding the reactor, in which the reactor licensee has the authority to determine all activities including exclusion or removal of personnel and property from the area....Activities unrelated to operation of the reactor may be permitted in an exclusion area under appropriate limitations, provided that no significant hazards to the public health and safety will result.
- 4 Paragraph 50.59(c)(2) of 10 CFR Part 50 states, in part, that, A licensee shall obtain a license amendment pursuant to §50.90 prior to implementing a proposed change, test, or experiment if the change, test, or experiment would... (v) Create a possibility for an accident of a different type than any previously evaluated in the final safety analysis report (as updated).
Paragraph 50.71 (e) of 10 CFR Part 50 states, in part, that, Each person licensed to operate a nuclear power reactor...shall update periodically...the final safety analysis report (FSAR) originally submitted...to assure that the information included in the report contains the latest information developed. This submittal shall contain all the changes necessary to reflect information and analyses submitted to the Commission by the applicant or licensee or prepared by the applicant or licensee pursuant to Commission requirement since the submittal of the original FSAR, or as appropriate, the last update to the FSAR.
Paragraph 50.9(b) of 10 CFR Part 50 states, in part, that, Each applicant or licensee shall notify the Commission of information identified by the applicant or licensee as having for the regulated activity a significant implication for public health and safety or common defense and security.
The NRC staff used the following documents for guidance in its review.
NRC Regulatory Guide 1.181, "Content of the Updated Final Safety Analysis Report in accordance with 10 CFR 50.71 (e)," September 1999 (ADAMS Accession No. ML003740112),
endorses Revision 1 of Nuclear Energy Institute (NEI) 98-03, "Guidelines for Updating Final Safety Analysis Reports," June 1999. NEI 98-03, Appendix A3, "Reformatting of Updated FSAR
[UFSAR] Information," states, in part,.....licensees should evaluate potentially significant changes in the site environs...to determine if notification of NRC and appropriate update of the UFSAR are required."
NUREG-0800, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR [Light-Water Reactor] Edition [SRP]," Section 2.2.1-2.2.2, "Identification of Potential Hazards in Site Vicinity," and Section 2.2.3, "Evaluation of Potential Accidents," were used for guidance in the review of man-made hazards.
NRC Generic Letter 81-06, "Periodic Updating of Final Safety Analysis Reports (FSARs)," dated February 26, 1981 (ADAMS Accession No. ML031080517), states, in part, that "Analyses should be revised if safety (Le., 10 CFR § 50.59) or other considerations require such revision."
- 5
3.0 TECHNICAL EVALUATION
3.1 Proposed Changes to the FSAR The phases for reaching compliance with the Tri-Party Agreement are identified in three parts:
Non-intrusive Surveillance and Characterization Activities Intrusive Sampling Activities Final Cleanup/Removal Activities The licensee's amendment request dated April 28, 2010, as supplemented by letter dated August 9, 2010, addresses only the non-intrusive surveillance and characterization activities.
The licensee determined that the following FSAR sections required revision.
(1) Section 2.1, "Geography and Demography" The licensee proposes to revise Section 2.1.2.2, "Control of Activities Unrelated to Plant Operation," to identify the planned DOE 618-11 site non-intrusive surveillance and characterization activities within the CGS exclusion area and to delineate DOE authority and control for the non-intrusive activities, including lead responsibility for abnormal events at the 618-11 site.
(2) Section 2.2, "Nearby Industrial, Transportation, and Military Facilities" The licensee proposes to revise Section 2.2.2.1, "Description of Facilities," to expand the discussion of the activities of the DOE facilities within a 5-mile radius of the CGS site, including the 618-11 site. Table 2.2-1, "Hanford Site Nuclear Facilities," is being revised to update the status of DOE facilities within a 5-mile radius of the CGS site. For the 618-11 site, significant revisions to the table are provided to describe the new activity, identify the hazard, provide the DBE, and describe the impact on CGS as follows:
Reference to the WCH Basis for Interim Operation (BID) has been added to the facility description (the BID is similar to an NRC safety analysis).
The hazard now identifies radioactive waste hazards bounded by Cs-137, Sr-90, and Pu-239, and non-radiological hazards bounded by beryllium.
The DBE is listed as caisson penetration with fire.
The impact is discussed as particulate release effectively mitigated by soil overburden and project controls. No missiles are postulated.
- 6 (3) Section 3.5, "Missile Protection" The licensee proposes to revise Section 3.5.1.5, "Missiles Generated by Events Near the Site,"
to account for consideration of missiles generated from the 618-11 site activities. No missile hazards have been postulated for the non-intrusive characterization and surveillance activities at the 618-11 site. Missiles from other DOE facilities on the Hanford Site are currently discounted due to their distance from CGS.
3.2 Licensee Evaluation The licensee stated in its application that it conducted an evaluation to determine if any gaps existed at a regulation or implementation level for the non-intrusive characterization and surveillance activities as described in the DOE-approved documented safety analysis (DSA)
(WCH-183, Rev.1, "618-10 and 618-11 Waste Burial Grounds Basis for Interim Operation,"
August 2009) and controlled by the DOE-approved Technical Safety Requirements (TSRs)
(WCH-184, Rev.1, "Technical Safety Requirements for 618-10 and 618-11 Burial Sites," August 2009). The licensee stated that its evaluation was done by functional area in order to ensure a comprehensive review by functional area experts in the process. The gap analysis included the following functional areas to provide enveloping coverage: Licensing, Legal, Emergency Preparedness, Security, Radiation Protection, OperationslWork Control, Nuclear Safety, Engineering/Analysis, Fire Protection, Training, Industrial Safety, and Environmental.
Regulations, processes, and implementing procedures between WCH and EN were compared within each functional area to determine the degree of reliance EN could place on WCH procedures in support of 618-11 activities.
The licensee stated that WCH prepared the BID using DOE standards DOE-STD-3011-2002, "Guidance for the Preparation of Basis for Interim Operation (BID) Documents," in accordance with 10 CFR 830, "Nuclear Safety Management," requirements for a DSA and DOE-STD-1027 92," Hazard Categorization and Accident Analysis Techniques for Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports." The BID was developed from a hazards evaluation matrix. Known hazards were identified based on the best historical documentation available.
Strontium (Sr-90), cesium (Cs-137), and plutonium (Pu-239) were determined to be the bounding radionuclides for determination of potential dose consequences, while beryllium was determined to be the bounding element for determination of potential toxicological consequences. Hazard egress and dispersion methodologies were used in accordance with DOE guidance to determine on-site (at 100 meters) and off-site (at the Columbia River) doses.
The soil overburden was credited and included in the TSRs as a passive safety feature. The TSRs specifically prohibit removal of existing soil overburden.
3.2.1 Analysis of the 618-11 Site Design Basis Event The licensee stated in its application that the DOE determined that the 618-11 site DBE for the non-intrusive activities is a caisson penetration with fire accident (the same DBE is already included in CGS FSAR Table 2.2-1 for the 618-10 site, which is currently under remediation). A cone penetrometer inadvertently penetrates into a caisson and is assumed to induce an explosion in a waste package can located within the caisson. This explosion is assumed to pressurize the caisson and cause a release of radioactive material. The material remaining in
- 7 the caisson is assumed to be exposed to a fire and produce an additional release. The overall release is a combination of an explosion and fire.
The DOE calculated radiological dose consequences are 4.45 x 10-2 roentgen equivalent man (rem) (44.5 mrem) on-site (at 100 meters) and 5.10 x 10-5 rem off-site (at the Columbia River).
The dose consequences credit the soil overburden and consider the torturous path presented by the penetrometer within the puncture hole in the caisson.
DOE determined the bounding toxicological consequences for the 618-11 site DBE by evaluating potential beryllium concentrations. Of the non-radiological hazardous materials potentially disposed in the 618-11 site, beryllium has the lowest exposure limits by a significant margin. The calculated beryllium oxide release concentration (4.6 x 10-3 mg/m3) is lower than its DOE Protective Action Criteria (PAC-1) concentration (1.39 x 10-2 mg/m 3) and requires no controls.
The licensee stated in its application that it conducted a top-down review of the proposed DOE activities. The activities are dealing with materials under the responsibility and control of DOE, not NRC. Accident Analyses per FSAR Chapter 15 are not applicable because these activities are not internal, light-water reactor, NRC-regulated processes. This is an external event evaluated in accordance with 10 CFR 100.10 to assure that no safety-related or important-to safety structures, systems, or components (SSCs) are impacted, and that no credited operator actions are affected. In this manner, no new accident is postulated, and the mitigation of an analyzed event remains unaffected.
The DOE BID radiological dose consequence calculation for the 618-11 site DBE did not use CGS meteorological data to compute dispersions. The licensee performed a calculation (Calculation No. NE-02-09-06, "Accident Analysis for Phase 1 of Burial Ground 618-11 Remediation Activities," Rev. 0, dated October 28,2009) utilizing CGS meteorological data and FSAR dispersion methodology which results in a calculated radiological dose consequence of less than 0.1 rem at the exclusion area boundary (EAB) and at the closest control room intake, 300 meters from the source. This dose consequence does not pose challenges to any CGS SSCs, their operation, control room habitability, or any credited operator actions.
The DOE BID toxicological dose consequence for the 618-11 site DBE (4.6 x 10-3 mg/m3) is significantly less than the NRC toxicity limits for beryllium and its compounds (4 mg/m 3) specified in NRC Regulatory Guide (RG) 1.78, "Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated HazardOUS Chemical Release," December 2010 (ADAMS Accession No. ML013100014), and NUREG/CR-6624, "Recommendations for Revision of Regulatory Guide 1.78," July 1999 (ADAMS Accession No. ML003726870). The consequences were calculated at 100 meters from the source and will be further reduced by the distance to the closest control room intake, which is 300 meters from the source. The postulated chemical release will not result in any significant concentration in the control room and does not pose challenges to any CGS SSCs, their operations, control room habitability, or any credited operator actions.
- 8 3.3
NRC Staff Evaluation
The NRC staff reviewed the licensee's analysis and evaluation of the non-intrusive characterization and surveillance activities proposed by DOE at the 618-11 site as provided in the licensee's application dated April 28, 2010, as supplemented by letter dated August 9, 2010, and in the licensee's calculation NE-02-09-06, "Accident Analysis for Phase 1 of Burial Ground 618-11 Remediation Activities" (calculation not publicly available). The staff's review primarily focused on confirming that the proposed activities comply with 10 CFR 100.3 and that the licensee complied with the requirement of 10 CFR 50.71(e) to maintain a current and accurate FSAR. As noted in NRC-endorsed Nuclear Energy Institute (NEI) 98-03, Rev. 1, "Guidelines for Updating [FSARs]," this includes evaluating potentially significant changes in the site environs and determining if notification of the NRC and updating of the FSAR are required.
The NRC staff reviewed the following DOE documents to confirm the licensee's analysis and evaluation:
WCH-183, Rev.1, "618-10 and 618-11 Waste Burial Grounds Basis for Interim Operation," August 2009 (Official Use Only; not publicly available)
WCH-184, Rev.1, "Technical Safety Requirements for 618-10 and 618-11 Burial Sites," August 2009 (Official Use Only; not publicly available)
HNF-EP-0649, Rev. 0, "Characterization of the 618-11 Solid Waste Burial Ground, Disposed Waste, and Description of the Waste-Generating Facilities,"
October 1997 (ADAMS Accession No. ML102650079)
Letter from D. Brockman and J. Short (DOE) to C. Spencer (WCH), "Contract No.
DE-AC06-05RL14655 - Approval of Revision 1 to the 618-10 and 618-11 Waste Burial Grounds Basis for Interim Operation and Technical Safety Requirements Documents," July 17, 2009 (ADAMS Accession No. ML102650173)
The non-intrusive activities proposed by DOE at the 618-11 site include radiation surveys, scans using ground penetrating radar, mapping using electromagnetic induction, geophysical delineation of VPUs and caissons, use of a multi-detector probe inserted into GeoProbes TM or cone penetrometers that have been inserted using the direct push method, and soil samples taken in proximity to disposed waste to judge the potential spread of contamination.
DOE assessed the possibility for interaction with waste from these proposed activities and determined that two potential scenarios were apparent. Use of cone penetrometers along the centerline of the trenches could hit buried waste, and use of cone penetrometers adjacent to a VPU or caisson could conceivably bend or otherwise be diverted and hit the side of one of these underground structures. Precautions are in place in the WCH operating procedures to preclude this from happening. However, the potential for a cone penetrometer to be misdirected and pierce the side of a caisson bounds the consequences from interception of waste within a trench. Therefore, DOE conducted further analysis of this event.
In its evaluation of a caisson penetration by a misdirected penetrometer, DOE assumed a resultant fire and explosion. No specific initiator was identified based on the known contents of
- 9 a caisson, but DOE made a general assumption that the contents included flammable liquid or hydrogen gas trapped within a sealed container in the caisson. DOE assumed penetration of the caisson by the penetrometer induced an explosion within a container in the caisson, pressurized the caisson, and caused a release of radioactive material. Subsequently, DOE assumed a fire starts and adds to the release.
DOE determined the material at risk (assumed to be the total inventory of the waste site) based upon the entire 618-11 site source term. The site is comprised of 3 trenches, approximately 30,000 cubic meters each, with 3 to 5 large caissons measuring 2.4 meters in diameter by 3 meters long, and 50 VPUs measuring 0.56 meters in diameter by 4.6 meters long. The tops of the caissons are 4.6 meters below grade, they are not sealed, and the structure is open at the bottom. An offset pipe with a cap connected the caisson to the surface 4.6 meters above during burial site operations; however, since closure of the burial site, there is a minimum of 1.2 meters of soil overburden on top of the pipe cap. The caisson, being the most likely source for the largest concentration of radioactive material in a small location, was conservatively used by DOE for the event. The source term of a single caisson is conservatively considered by DOE to comprise 15 percent of the total radioactive material in the waste site.
Based on historical waste handling processes, DOE assumed 50 percent of the waste to be combustible. Airborne release fractions and respirable fractions were based on DOE-approved guidance. DOE assumed an explosion to affect 5 percent of the contents, and the fire to consume the top 0.3 meters of the container waste, or 10 percent.
DOE performed both unmitigated and mitigated analyses, the difference being that the mitigated release accounted for the soil overburden and the physical reality of the penetrometer being in the puncture hole and thus obstructing releases through that pathway. Two release paths were considered, either up through the offset pipe and its soil overburden, or past the penetrometer and up through the soil o"verburden. DOE concluded that the energy of the explosion and subsequent 'fire are not sufficient to displace the soil overburden and result in any release through the soil column. Based on the mitigation provided by the soil overburden, DOE applied a leak path factor of 0.005. This is comparable to the leak path factors credited for buildings with active ventilation systems or to the efficiency of a sand filter.
DOE calculated the resultant dose consequences for the mitigated analysis to be 5.1 x 10-5 rem at the Hanford Site boundary and 4.45 x 10-2 rem at 100 meters. These results are well below levels where additional controls are required for public or worker safety.
Crediting mitigation by the soil overburden is a design feature necessary to protect the assumptions of the DOE analysis. Therefore, the TSRs (WCH-184, Rev.1) include the soil overburden covering the caissons and VPUs as a design feature for the 618-11 site. Removal of the existing soil overburden is prohibited by the TSRs.
The NRC staff also noted that only the non-intrusive activities listed in section 2.4.3.1 of WCH-183, Rev.1, are approved by DOE for the 618-11 site. Intrusive activities are not approved by DOE for the 618-11 site.
In its calculation NE-02-09-06, Rev. 0, the licensee confirmed the DOE's analysis that the resultant dose consequences for the mitigated release are well below regUlatory limits. In
- 10 particular, the dose at the closest control room intake is 0.003 rem, as compared to the regulatory limit of 5 rem. The licensee confirmed that the beryllium concentration at 100 m from the source is well below the NRC toxicity limits specified in RG 1.78 and NUREG/CR-6624.
Based on its review of the licensee's evaluation as presented in its application dated April 28, 2010, as supplemented by letter dated August 9, 2010, and the licensee's calculation NE-02-09-06, and comparison with the DOE-approved BIO and TSRs, the NRC staff concludes that appropriate limitations have been established to conduct non-intrusive characterization and surveillance activities at the 618-11 site with due regard to the public health and safety, and that the licensee has appropriately evaluated the proposed change to the CGS site environs.
Therefore, the NRC staff concludes that the proposed changes to the FSAR comply with 10 CFR 100.3 and 10 CFR 50.71 (e) and are acceptable for the DOE non-intrusive characterization and surveillance activities at the 618-11 site.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Washington State official was notified of the proposed issuance of the amendment. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding published in the Federal Register on June 29,2010 (75 FR 37473). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: F. Lyon Date:
October 25 t 2010
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