ML12300A121
| ML12300A121 | |
| Person / Time | |
|---|---|
| Issue date: | 06/07/2013 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| Orr M | |
| Shared Package | |
| ML12300A089 | List: |
| References | |
| DG-1282 RG-1.137, Rev 2 | |
| Download: ML12300A121 (6) | |
Text
Response to Public Comments on Draft Regulatory Guide (DG) -1282 Fuel Oil Systems for Emergency Power Supplies Proposed Revision 2 of Regulatory Guide (RG) 1.137 A notice that Draft Regulatory Guide, DG-1282 (Proposed Revision 2 of RG 1.137) was available for public comment was published in the Federal Register on July 5, 2012 on page 77 FR 39745. On August 13, 2012, the public comment period was extended from August 31, 2012 until September 28, 2012 by 77 FR 48177. Comments were received from the organizations listed below. The NRC has combined the comments and NRC staff disposition in the following table.
Comments were received from the following:
John C. Butler (NEI-1) Mark Richter (NEI-2) David P. Helker, Manager, (Exelon)
Nuclear Energy Institute (NEI) Nuclear Energy Institute (NEI) Licensing and Regulatory Affairs 1776 I Street NW, Suite 400 1776 I Street NW, Suite 400 Exelon Generation Co., LLC Washington DC 20006 Washington, DC 20006 200 Exelon Way ADAMS Accession No. ML12214A372 ADAMS Accession No. ML12277A342 Kenneth Square, PA 19348 ADAMS Accession No. ML12286A385 Comment Section of Comment NRC Response From DG-1282 NEI-1 All NEI requests a 30-day extension of comment period. The NRC agreed to a 30-day extension to the comment period. In a Federal Register notice (77 FR 48177), the NRC extended the deadline for submitting comments on DG-1282 to September 28, 2012.
Exelon General American oil refiners supply diesel fuel to the commercial market in Do not agree - ASTM D-975 prescribes the required accordance with the latest version of ASTM D-975. properties of diesel fuels at the time and place of delivery.
Licensees need to ensure that selected properties of fuel oil Therefore, Exelon recommends removing citations to specific years meet the requirements of the onsite emergency diesel of this standard throughout the draft RG standard since the citations generators (EDGs). Future revisions to ASTM standards may might rapidly become obsolete. make changes to the acceptance criteria that may impact reliable operation of EDGs. It is therefore imperative for licensees to evaluate the changes for plant specific applications prior to accepting the fuel for onsite EDGs.
Hence the specific vintages of standards that have been reviewed and found acceptable need to be maintained in the RG.
Exelon Paragraph Exelon considers that the discussion in this paragraph related to Do not agree - This RG provides recommendations for C.4 severe natural event or major disaster causing interruption of onsite immediate and short term fuel oil requirements. Many Singh diesel fuel replenishment might be premature, given that the nuclear licensees have established agreements with fuel oil suppliers November 2012June 2013
Comment Section of Comment NRC Response From DG-1282 energy industry is currently developing a comprehensive strategy to for emergency replenishment as a defense-in- depth measure.
implement the lessons learned from the Fukushima event in Japan. These agreements facilitate delivery of fuel oil required for This strategy, known as "FLEX," is being developed by the Nuclear site specific application and ensure reliable EDG operation.
Energy Institute (NEI) to deliver a diverse and flexible coping These recommendations may supplement long term actions capability in these events. also.
Exelon believes that the prescriptive instruction in this paragraph for Part of the NRCs response to the Fukushima event in Japan establishing pre-disaster fuel replenishment agreements and onsite was the issuance of the Mitigating Strategies Order, EA temporary storage tanks is not necessary given this comprehensive 049, which does not require the use of diesel driven industry initiative, and recommends that this discussion be equipment. While certain synergies would be obtained reconsidered. through the use of diesel driven equipment, should a licensee choose to use a different form of engine for the portable equipment responsive to EA-12-049, the arrangements that are made for consumables for that equipment might be incompatible with emergency diesel generators.
Exelon Paragraph Appendix B of ANSI/ANS-59.51 - 1997, "Alternate Calculation of Do not agree - Licensees using time dependent method C.5 Usable Fuel Oil Storage Capacity," contains a provision for the typically assume worst case accident loading of the EDG Singh calculation to include: 1) an allowance for an operator to supply (such as during a large break LOCA) for first few hours of power to equipment other than the minimum required for the plant EDG operation and assume load shedding can be condition, 2) an explicit allowance for periodic testing, and 3) an accomplished based on engineering judgment for the balance additional 10% margin to account for remaining uncertainties. of hours. Depending on the size of break postulated in the Exelon believes that the justification for the NRC to not accept the primary or secondary systems, the worst case EDG loading time-dependent method for calculating fuel storage requirements that from fuel oil consumption perspective may not be a large is discussed in the second to last sentence of the introductory break LOCA. In addition, symptom based emergency paragraph to Section C.5 is unwarranted. operating procedures may dictate operators to connect additional loads that may not have been considered in the Therefore, Exelon suggests that the NRC consider deleting this EDG fuel oil consumption calculations. Hence, for bounding sentence from the final revision. analyses, the 7-day operation at rated capacity is recommended in this RG. Licensees of operating plants can continue using RG 1.137, Revision 1, and have the option to use Revision 2 of RG 1.137.
Exelon Paragraph Exelon believes that it is common practice to include the volume of Do not agree - The intent of section 5.4 of ANSI/ANS-59.51-C.5.1 fuel in day or integral tanks, piping, etc., in the usable fuel storage 1997 is to provide guidance on sizing of storage tanks. There Singh calculations, since this fuel meets all specification requirements and is are specific requirements for supply tanks and day tanks.
viable fuel for operation of the machine. There is no guidance on storing fuel in piping. Licensees who have used up the available margin in the original design Therefore, Exelon suggests that the NRC consider deleting this basis of the plant tank sizing criteria have credited fuel discussion since there appears to be no reasonable technical basis for available in the system piping or day tanks to comply with its inclusion. their existing licensing basis. Licensees of operating plants can continue using RG 1.137, Revision 1, and have the option June 2013 2
Comment Section of Comment NRC Response From DG-1282 to use Revision 2 of RG 1.137.
NEI-2 Paragraph This section precludes facilities from taking credit for the useable Do not agree - The intent of section 5.4 of ANSI/ANS-59.51-C.5.1 volume within the day (or integral) tanks on the emergency diesel 1997 is to provide guidance on sizing of storage tanks. There generators (EDG) when calculating the 7-day useable volume. Some are specific requirements for supply tanks and day tanks.
Singh plants currently take credit for their day tank volumes, and There is no guidance on storing fuel in piping. Licensees disallowing this practice could potentially require a facility to install who have used up the available margin in the original design additional storage volume in order to meet the requirements of the basis of the plant tank sizing criteria have credited fuel draft RG. Given the lower heat content of ultra-low sulfur diesel available in the system piping or day tanks to comply with (ULSD) fuel, all nuclear facility storage volume margins were their existing licensing basis. As indicated in the comment, reduced by transitioning to ULSD. As a result, some facilities the previous version of RG 1.137 did not explicitly clarify the included the day tank storage volume to avoid adding additional requirements of each tank. The intent of Revision 2 is to storage tank capacity. The previous revision of RG 1.137 did not clarify the separate and conservative design criteria for preclude use of day tanks in the 7-day useable volume calculation. supply and day tanks. Licensees of operating plants have the option to use Revision 2 of RG 1.137.
Revise C5.1 so that it does not preclude use of day (or integral) tank volumes in the 7-day useable volume calculation, or provide a basis for this additional requirement.
Exelon Paragraphs Exelon believes that the example of a 2% or more capacity change Agree - The example given, [e.g., a 2% or more capacity C.5.3 and due to use of Ultra-Low Sulfur Diesel (ULSD) fuel oil seems change (as applicable) for use of ultra low sulfur diesel Bob C.5.4 excessive and might be without practical technical basis. Exelon has (ULSD) fuels], has been deleted.
analyzed and trended information of tests of ULSD fuel oil samples.
The tests indicate that the heat content on a volumetric basis, and The NRC staff has not endorsed a specific test method to thereby the tank capacity to achieve the 7-day storage goal, follows establish heat content in fuel oil. The test method is the correlation established in ASTM D-4868, "Standard Test Method determined by the licensee.
for Estimation of Net and Gross Heat of Combustion of Burner and Diesel Fuels," to within 1%. Figure 1 is being provided for information and reference purposes and helps to depict the test result trending data.
Exelon suggests that licensees be afforded the option to perform actual heat content testing to establish limiting values. ASTM D-4809, "Standard Test Method for Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter (Precision Method),"
provides a state-of-the-art method for determining this value.
Exelon Paragraph Emergency Diesel Generator (EDG) manufacturers typically utilize The NRC staff agrees with the comment. This paragraph has 6.1 positive-displacement engine-driven fuel pumps to transfer the fuel been modified to read, Net positive suction head Bob from the day tank to feed the engine fuel rail. These pumps have self- requirement of the pump fed from the day tank, if priming suction lift capability and Net Positive Suction Head (NPSH) applicable, requirements would not necessarily apply.
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Comment Section of Comment NRC Response From DG-1282 Therefore, under these circumstances, Exelon suggests that this paragraph be removed or modified accordingly.
NEI-2 Paragraph This section addresses protection against internal and external The NRC staff believes the wording in the draft RG is C.9.1 corrosion by use of coatings and/or cathodic protection, as adequate as is. No changes are necessary.
appropriate. Guidance is provided for internal coating performance.
Burke The section does not provide guidance for needed actions for Internal tank coatings, whether they are classified as Coating internally coated tanks that may not meet the recommended coating Service Level III in accordance with RG 1.54 Rev 2, or not, performance criteria. that are not qualified for the service conditions or are degraded such that detachment of the coating from the tank Revise C.9.1 to include guidance for addressing internally coated wall is considered likely before the next inspection should tanks that may not meet the recommended coating performance have a failure mode analysis performed. The failure mode criteria. analysis is to include an evaluation of whether failed, or detached coatings, or resultant corrosion products, block fuel oil filters downstream of the tank, thus affecting diesel generator reliability or performance.
Exelon Paragraph Substituting the standards of ASTM D-4057, "Practice for Manual Agree - Paragraph C13.1 has been changed to reflect these C.13.1 Sampling of Petroleum and Petroleum Products," for ASTM D-2276, comments. ASTM D-6217 is a better standard to use than Emma "Standard Test Method for Particulate Contaminant in Aviation Fuel ASTM D-2276, therefore the NRC staff has included this by Line Sampling," appears inconsistent with the Bases of Improved standard. ASTM D-4057 is still cited as a good way to obtain Technical Specifications Surveillance Requirement (SR) 3.8.3.3 of the samples.
NUREG-1431 and NUREG-1433. As applied in nuclear plants, ASTM D-4057 is used to obtain "grab" samples from the delivery tankers in order to perform fuel acceptance testing. Flowing samples per ASTM D-2276 are obtained for the periodic storage testing for particulates in order to provide a sample of the fuel that is representative of that which is going to the engine. An alternative to ASTM D-2276 successfully used by many operating nuclear plants is ASTM D-6217, "Standard Test Method for Particulate Contamination in Middle Distillate Fuels by Laboratory Filtration."
Therefore, Exelon recommends that this paragraph cite ASTM D-6217 as an alternative to ASTM D-2276, and not cite ASTM D-4057 as currently proposed.
Exelon Paragraph The range for American Petroleum Institute (API) gravity (or specific Agree - Paragraph C13.2 has been changed to reflect this C.13.2 gravity) cited in Appendix C of ANSI/ANS 59.51-1997, comment. Since the specific gravity of ULSD and other fuels Emma "Recommended Fuel Oil Practices," was developed prior to the may not be within the range cited in ANSI/ANS 59.51-1997 advent of ULSD and may need to be modified by individual plants in and the important attributes are the energy content and that order to reflect the properties of locally-available diesel fuel and/or in the fuel would accommodate the 7-day requirement, the NRC June 2013 4
Comment Section of Comment NRC Response From DG-1282 order to accommodate the 7-day volumetric storage criterion. staff has deleted the last sentence.
Therefore, Exelon recommends that the last sentence of this paragraph be deleted for this draft RG.
Exelon Paragraph The Bases for SR 3.8.3.3 of Improved Technical Specifications Agree - Paragraph C13.3.2 has been changed to reflect this C.13.3.2 NUREG-1431 and NUREG-1433, allows for the determination of a comment. In the Improved Technical Specifications the Emma clear and bright appearance with proper color per ASTM D-4176, alternative of clear and bright with proper color is "Standard Test Method for Free Water and Particulate available. Therefore to have consistent guidance, the NRC Contamination in Distillate Fuels (Visual Inspection Procedures)" as staff has added these words to the RG.
a choice in place of specific water and sediment testing per ASTM D-2709, "Standard Test Method for Water and Sediment in Middle Distillate Fuels by Centrifuge." By contemporary standards, diesel fuel should be clean and dry.
Therefore, Exelon suggests that this paragraph be revised to include the phrase "clear and bright with proper color" as an alternative to
'water and sediment" to reflect contemporary state-of-the-art practice for fuel delivery acceptance.
Exelon Paragraph This paragraph is intended to check for and remove any water that Do not agree - Water in the day tanks and the integral tanks C.13.5 may have been transferred from the storage tank and may have settled may also come from other sources besides the storage Emma out in the day and integral tanks. The requirement to laboratory (supply) tank. Therefore, the NRC staff believes that centrifuge the sample per ASTM D-2709 is not necessary because checking for water should be performed in the day and water in the storage tanks has been removed in the monthly checks integral tanks and no changes are necessary.
per Paragraph 13.4 of this draft Regulatory Guide. Only minimal amounts of water could appear at the bottom of the day tank which is easily removed by draining a sufficient volume of oil from the tank bottom. Operating experience has shown that little-to-no water appears at this location in the system. Exelon believes that the use of ASTM D-2709 standards for this practice imposes an unnecessary burden on licensees.
Therefore, Exelon suggests that the wording of this paragraph remain as currently discussed in Revision 1 of RG 1.137 (1979).
NEI-2 Paragraph This section addresses monitoring of the on-hand fuel supply to Agree - Paragraph C13.8 has been changed to reflect this C13.8 ensure reliability and availability of the fuel oil system. Included is a comment. The staff has reviewed ASTM D6469-11 and has Emma recommendation for taking biological cultures to assess the presence found it to be good guidance for microbiological of fungus and bacteria. No standard or technique is specified for contamination. Therefore, the NRC staff has added this taking the cultures. This section also does not provide guidance for standard. Also the NRC staff has added ASTM D6217-11 for particulate contamination testing, which may be an indicator of particulate testing.
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Comment Section of Comment NRC Response From DG-1282 oxidation in aging fuel.
Revise C13.8 to include a reference or standard for performing fungus and bacteria cultures. Include a recommendation to perform visual inspection for evidence of fungus and bacteria during maintenance evolutions. Guidance should also be provided for actions if fungus and/or bacteria are detected in the fuel oil. Include a recommendation for periodic particulate contamination testing.
Exelon Paragraph The specification for ULSD (15 ppm sulfur maximum) first appeared Agree - Paragraph C.13.10 has been changed to reflect this C.13.10 in the 2006 version of ASTM D-975, "Standard Specification for comment. The NRC staff has changed the year on the Emma Diesel Fuel Oils," not in the 1992 version as stated in this paragraph. standard to -06 for clarification.
Use of versions of ASTM D-975 prior to 2006 will not address ULSD fuel. Use of versions of ASTM D-975 from 1993 until 2005 address Low Sulfur Fuel which has a maximum sulfur content of 0.05% or 500 ppm, but do not address ULSD. Use of 1992 version and earlier editions of ASTM D-975 address only 5000 ppm sulfur fuel, which is now known as "high sulfur fuel."
Exelon recommends that the NRC consider providing the appropriate clarification concerning this aspect.
NEI-2 Paragraph This draft revision of RG 1.137 endorses use of ASTM D975-11 Do not agree - Paragraph C.13.11 was intended to be for C 13.11 "Standard Specification for Diesel Fuel Oils." ASTM D975-11 awareness of biodiesel and that it could be present in ASTM Emma considers blends containing up to 5% biodiesel not to be a biodiesel D975-11 diesel fuel. Since this section was for awareness, grade fuel. There is the potential that fuel purchased to this standard allowing a provision for another standard is not needed.
may not be free of biodiesel products. This imposes the need for Therefore, the wording in this paragraph does not need to be independent supplier verification of biodiesel content. Biodiesel fuels changed.
have the potential to adversely affect the performance of diesel engines.
Include a provision in RG 1.137, C13.11 that allows use of an alternative fuel standard (such as Jet A specification fuel which conforms to ASTM Standard D1655) that addresses the concerns regarding biodiesel content and complies with existing licensee requirements for EDG operation and long-term fuel storage.
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