Environmental statements; availability, etc.: Portland General Electric Co.,

 
CONTENT

[Federal Register: October 28, 1998 (Volume 63, Number 208)]

[Notices]

[Page 57713-57715]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr28oc98-111]

NUCLEAR REGULATORY COMMISSION

[Docket No.: 71-9271]

Portland General Electric Co.; Issuance of Environmental Assessment and Finding of No Significant Impact Regarding the Proposed Exemptions From Requirements of 10 CFR Part 71

Portland General Electric Company (PGE or applicant) has applied for a package approval from the U.S. Nuclear Regulatory Commission (NRC) for the one-time shipment of the Trojan Reactor Vessel Package (TRVP), with internals intact, from the Trojan Nuclear Plant site at Rainier, Oregon, to the US Ecology radioactive waste disposal facility near Richland, Washington. As part of its application, PGE has requested exemptions, pursuant to 10 CFR 71.8, from requirements 10 CFR 71.71(c)(7) and 10 CFR 71.73(c)(1). This Environmental Assessment (EA) was prepared to assess the potential environmental impacts of granting these exemptions as well as an exemption from 10 CFR 71.73(b) to the extent it is needed to grant an exemption from 10 CFR 71.73(c)(1).

Identification of Proposed Action

By letter dated March 31, 1997, PGE requested, in part, approval for the one-time shipment of the TRVP by means of two specific exemptions, under 10 CFR 71.8, from the requirements of 10 CFR 71.71(c)(7) and 71.73(c)(1), in the 10 CFR part 71 regulations governing the packaging and transportation of licensed materials.

The TRVP is the Trojan reactor vessel prepared for transport as a shipping package. The reactor vessel is a large, thick-walled, steel structure measuring approximately 13 m (42 feet, 6 inches) in length and 5.2 m (17 feet, 1 inch) in outside diameter. The reactor vessel void space, with internals installed and intact, will be filled with low-density cellular concrete, to prevent movement of radioactive material within the reactor vessel. The vessel will be sealed and shielded as necessary to meet the dose limit requirements of 10 CFR 71.47 and 10 CFR 71.51. Impact limiters will be installed to minimize reactor vessel stresses associated with the analyzed TRVP drops. The impact limiters are each approximately 1.5 m (4 feet, 10 inches) in width and 7.6 m (28 feet) in outside diameter. The maximum gross weight of the TRVP is conservatively 925 metric tons (2.04 million pounds).

The TRVP will be shipped approximately 482 km (300 miles) as a one- time, exclusive use, radioactive material transportation package for the purpose of disposal at the US Ecology low-level radioactive waste facility on the Hanford Nuclear Reservation near Richland, Washington. During the shipment, the TRVP is expected to be outside the Trojan Nuclear Plant site and US Ecology facility boundaries less than 72 hours.

Section 71.71(c)(7) requires an evaluation of the package design under normal conditions of transport and must include a determination of the effect, on that design, of a free drop of the specimen through a distance of 0.3 m (1 foot) [for a package weighing more than 15000 kg (33,100 pounds)] ``* * * onto a flat, essentially unyielding, horizontal surface in a position for which maximum damage is expected.''

Before shipment, the TRVP will be prepared as a shipping package and will be loaded and tied down onto a specially designed transporter. The loaded transporter will be moved onto

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a specially selected barge and secured using an engineered tie-down system. The barge will be grounded during this evolution. The TRVP loaded transporter will be barged up the Columbia River to the Port of Benton where a heavy-haul mover will connect to the transporter and move it off the barge and overland to the disposal facility. The TRVP will be off-loaded at the disposal facility.

The TRVP will be rotated to a horizontal position (i.e., the centerline longitudinal axis of the package will be horizontal) during preparation in the Trojan Nuclear Plant industrial area. During transport, the TRVP will remain oriented in the horizontal position. Because of the unique size and mass of the package and the method of support of the package, no other orientation is reasonable during TRVP transport. Once loaded onto the transporter, the TRVP will not be removed from the transporter at any time during transport.

Based on the above conditions and the special handling and operational controls to be exercised, PGE requested exemption from the requirement to consider the 0.3 m (1 foot) drop (in any orientation) as a normal condition of transport. PGE has, however, designed and analyzed the TRVP with impact limiters to withstand the effects of a 0.3 m (1 foot) horizontal orientation drop.

Section 71.73(c)(1) concerns tests for hypothetical accident conditions and requires: ``A free drop of the specimen through a distance of 9 m (30 feet) onto a flat, essentially unyielding, horizontal surface, striking the surface in a position for which maximum damage is expected.'' Based on the Safety Analysis Report (SAR) specified transportation route, method of shipment, and special controls [including 18.5 km/h (10 knots) and 8 km/h (5 mi/h) speed limits for river and road, respectively], the PGE contends the 9 m (30- foot) drop should not be considered a hypothetical accident condition for the TRVP shipment. PGE determined that the maximum postulated distance that the TRVP could drop during a hypothetical transport accident is 3.3 m (11 feet), based on the transportation system, route, and operational controls. This drop height and horizontal orientation were used as a design basis for the TRVP. Because the TRVP shipment is conditioned on a minimum initial TRVP temperature of 50 deg.F, and on a forecasted minimum daily low temperature during transport of 40 deg.F, the 11-foot drop and puncture were evaluated at 45 deg.F, rather than the -20 deg.F which otherwise would be required by 10 CFR 71.73(b).

PGE designed the TRVP and analyzed its performance under accident conditions that are not as rigorous as those specified in 10 CFR 71.73(c)(1), and therefore requested exemption from that requirement. To assure comparable shipment safety, PGE has committed to the use of stringent operational and administrative controls. The purpose of these controls is to ensure that the probability of the TRVP encountering accident conditions beyond those for which it has been analyzed is low.

Need for the Proposed Action

The Trojan Nuclear Plant was shut down in November 1992. On January 27, 1993, PGE notified the NRC of its decision to permanently cease power operations and subsequently defueled the reactor, storing the spent fuel in the Trojan spent fuel pool. Currently, PGE has a possession-only license under 10 CFR part 50, and on January 25, 1995, applied to terminate its license by submitting a decommissioning plan. PGE proposed to decommission the facility using a dismantlement or DECON approach as defined in the ``Final Generic Environmental Impact Statement on Decommissioning of Nuclear Facilities,'' NUREG-0586, dated August 1988.

In accordance with the NRC-approved decommissioning plan, PGE's plans for decommissioning the Trojan Nuclear Plant include decontamination and dismantlement of contaminated structures, systems, and components. The removal of the Trojan reactor vessel and the internals is an evolution that is discussed in the decommissioning plan, and is necessary for completion of decommissioning and release of the site for unrestricted use.

Certain normal- and accident-condition test requirements of 10 CFR 71 [i.e., 10 CFR 71.71(c)(7) and 71.73(c)(1)] are impractical for the proposed shipment of the TRVP. They would significantly increase the size and cost of impact limiters attached to the reactor vessel. Larger impact limiters would raise the center of gravity of the TRVP in its transport configuration, resulting in a larger actual drop height that could occur during the shipment. Larger impact limiters could also make the shipment by barge physically impossible because a slightly taller package would not fit under the minimum overhead clearance point for the shipment route. Furthermore, installation of larger impact limiters would result in an increase in occupational dose to the workers performing the installation, which is not in keeping with the as low as reasonably achievable (ALARA) concept. Thus, exemptions from the requirements of 10 CFR 71.71(c)(7), and 71.73(c)(1) and the related exemption from 71.73(b), are needed to approve use of the TRVP for transport.

Environmental Impacts of the Proposed Action

NRC has considered the impacts of radioactive material transportation in general in its ``Final Environmental Statement on the Transportation of Radioactive Material by Air and Other Modes,'' (NUREG-0170, December 1977). The one-time, short-duration shipment of the TRVP will be made along a well-defined, favorable transportation route to the U.S. Ecology licensed radioactive waste disposal facility. The staff has established, by evaluation of the revised SAR and transportation Probabilistic Safety Study (PSS) and by personal interviews with the U.S. Coast Guard and the U.S. Department of Transportation (DOT), that the operational and administrative controls provide reasonable assurance that the TRVP will not encounter accident conditions during the shipment beyond those for which it has been analyzed. Therefore, any stress to the TRVP from normal or credible accidents is not expected to have impacts that would lead to radiological releases.

The PSS shows that the most likely of the accident scenarios is a TRVP barge collision, with the TRVP lost overboard (probability of 10-\6\ for the shipment). PGE has developed a recovery plan for this scenario that indicates that the TRVP would be recovered in about 30 days. Since the probability of accidents that could damage the package and lead to potential health impacts is less than 10-\6\, these accidents were not evaluated by the staff. The staff concluded that the TRVP shipment will not significantly affect the public health and safety, or adversely impact the environment.

Alternative to the Proposed Action

The alternative to the proposed action is to not grant the exemptions from 10 CFR part 71, which would then require other approaches to disposition of the Trojan reactor vessel and evaluation of its environmental impacts. Three other disposition scenarios were considered for the disposal of the reactor vessel and internals from the Trojan Nuclear Plant:

  1. No Action

    Storage of the reactor vessel on site. On-site storage of the reactor vessel with its internals intact is not considered to be a viable alternative. Federal regulations (10 CFR 50.82(a)) provide for decommissioning within 60 years, unless a longer period is approved by

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    the Commission, in accordance with the regulations. Storing the vessel on-site for 50 years before removal is similar to the SAFSTOR decommissioning alternative, which was addressed in NUREG-0586, ``Final Generic Environmental Impact Statement on Decommissioning of Nuclear Facilities.'' On-site storage for 50 years is not consistent with the DECON decommissioning alternative that was selected by PGE and approved by NRC. The DECON decommissioning alternative has also been accepted and approved by the State of Oregon for the decommissioning of the Trojan Nuclear Plant. On-site storage of the reactor vessel would result in retaining the part 50 license and necessary staff to maintain radiological controls and other part 50 required programs. Other results include, but are not limited to, performance of required periodic surveys, increased exposure to workers, and increased cost. Although radioactive decay would reduce shielding requirements, the reactor vessel would still have to be disposed of using one of the alternatives described below. Since insignificant gain would be realized, this scenario was not evaluated further.

  2. Modified Reactor Vessel and Internals Removal (Modified TRVP)

    Disposal of the reactor vessel in one piece with only the non- greater than Class C (non-GTCC) internals left inside. The TRVP, with all internals included, is classified as Class C waste. Certain internals, if removed from the TRVP, would likely be classified as GTCC waste. The GTCC internals would have to be segmented underwater, placed into containers, and stored in the spent fuel pool or the independent spent fuel storage installation (ISFSI) at the Trojan Site. The vessel and remaining internals would be shipped via barge in a single package similar to the TRVP alternative. Depending on the package shipped, NRC and/or DOT exemptions might still be required. The GTCC internals would be shipped at an unknown date in the future when a suitable repository becomes available to accept the waste.

  3. Separate Disposal

    Separate disposal of the reactor vessel and internals. The reactor vessel internals would be segmented underwater. The non-GTCC internals would be placed in shielded casks and shipped to the US Ecology disposal facility via truck. The GTCC internals would be stored in the spent fuel pool or the ISFSI at the Trojan site. The reactor vessel would be disposed of separately from the internals and either shipped whole, via barge, or segmented and shipped, via truck, to the disposal facility. Depending on the package shipped, NRC and/or DOT exemptions might still be required. The GTCC internals would be shipped at an unknown date in the future when a suitable repository becomes available to accept the waste.

    Radiation exposures for the proposed action and the other disposition options were analyzed for on-site personnel, transportation personnel, general public, and disposal facility workers. The number of radioactive waste shipments for each scenario was based on the amount and configuration of the waste produced. Dose estimates do not include doses resulting from on-site storage and future shipment of GTCC waste to a waste repository (date and site unknown).

    The proposed TRVP action has one radioactive waste shipment and a total exposure of 0.674 person-Sv (67.4 person-rem) [0.671 person-Sv (67.1 person-rem) of occupational exposure to on-site personnel]. Alternative A is inconsistent with the NRC-approved decommissioning plan for the site, and the impacts do not differ significantly from the proposed action. Alternative B would entail three radioactive waste shipments and a total exposure of 0.881 person-Sv (88.1 person-rem)

    [0.878 person-Sv (87.8 person-rem) of occupational exposure to on-site personnel] . Alternative C would involve 47 radioactive waste shipments and a total exposure of 1.389 to 1.399 person-Sv (138.9 to 139.9 person-rem) (1.332 person-Sv (133.2 person-rem) of occupational exposure to on-site personnel).

    Agencies and Persons Contacted

    Officials from the DOT Office of Hazardous Materials Technology, and the U.S. Coast Guard, Marine Safety Office/Group Portland, were contacted regarding impacts of the proposed action and had no concerns.

    Finding of No Significant Impact

    The environmental impacts of the proposed action have been reviewed in accordance with the requirements of part 51. Based on the foregoing EA, the Commission finds that the proposed action of: (1) Granting an exemption from 10 CFR 71.71(c)(7), so that PGE need not evaluate a free drop of 0.3 m (1 foot) under normal conditions of transport; and (2) granting an exemption from 10 CFR 71.73(c)(1) and 71.73(b), so that PGE need not evaluate a free drop of 9 m (30 feet) under hypothetical accident conditions, will not significantly impact the quality of the human environment. Accordingly, the Commission has determined not to prepare an environmental impact statement for the proposed exemption.

    This application was docketed under part 71, Docket 71-9271. For further details about this action, see Dockets 50-344 and 72-017, which are available for public inspection at the Commission's Public Document Room, 2120 L Street, NW, Washington, DC 20555, and the Local Public Document Room at Portland State University Library, Science Library, 951 Southwest Hall Street, Portland, Oregon 97201.

    Dated at Rockville, MD, this 22nd day of October 1998.

    For the Nuclear Regulatory Commission. M. Wayne Hodges, Acting Director, Spent Fuel Project Office, Office of Nuclear Material Safety and Safeguards.

    [FR Doc. 98-28813Filed10-27-98; 8:45 am]

    BILLING CODE 7590-01-P