ML15083A094

Columbia Generating Station, TIA XXXX-XX, Tower Makeup System Unresolved Issue

ML15083A094
Person / Time
Site:	Columbia
Issue date:	03/06/2015
From:	Gregoire D W Energy Northwest
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GO2-15-039, IR 2014002
Download: ML15083A094 (44)

Text

ENERGY NORTHWEST Donald W. Gregoire P.O. Box 968, PE20 Richland, WA 99352-0968 Ph. 509-377-8616 1 F. 509-377-4317 dwgregoire@energy-northwest.corn March 6, 2015 G02-15-039 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001

Subject:

COLUMBIA GENERATING STATION, DOCKET NO. 50-397;TIA XXXX-XX, TOWER MAKEUP SYSTEM UNRESOLVED ISSUE

Reference:

Letter GI2-14-067 from NH Taylor (NRC) to ME Reddemann (Energy Northwest) dated May 7, 2014, "Columbia Generating Station -NRC Integrated Inspection Report 05000397/2014002."

Dear Sir or Madam:

The Nuclear Regulatory Commission (NRC) has identified unresolved issue (URI)05000397/2014002-02 (Reference), related to potential discrepancies noted when reviewing Columbia Generating Station's licensing basis documents.

This involved the support role of the Tower Makeup System (TMU) to the Ultimate Heat Sink (UHS)System and the TMU's safety classification.

Energy Northwest (EN) has performed an extensive research of the licensing basis and support documentation, and has prepared the attached white paper report. The white paper summarizes findings from the research which support EN's proposed position with respect to URI 05000397/2014002-02.

EN respectfully requests consideration of the position presented in the white paper as part of the TIA process for resolution of the URI.There are no commitments contained in this letter or the enclosure.

Should you have any questions, please call JR Trautvetter at (509) 377-4337.Respectf ully DW Gregoire Manager, Regulatory Affairs

Attachment:

As stated Cc: NRC RIV Regional Administrator NRC NRR Project Manager NRC Sr. Resident Inspector

-988C AS Mohseni, Deputy Director, NRC Division of Policy and Rulemaking C Sonoda -BPA/1 399 w/o WA Horin -Winston & Strawn TIA XXXX-XX, TOWER MAKEUP SYSTEM UNRESOLVED ISSUE Attachment License Basis Evaluation of Columbia Generating Station's Tower Makeup System White Paper March 2015 TABLE OF CONTENTS SECTION TITLE PAGE 1.0 P U R P O S E .............................................................................................

.2 2.0 BACKGROUND

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3 2.1 Safety Assessment

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3 2.2 TMU Design, Operation, and Maintenance

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3 2.3 Dates of Significance

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4 2.4 Changes of Company and Plant Names .........................................

5 2.5 Historical License Basis for the TMU System ..................................

5 3.0 DEFINITION OF ULTIMATE HEAT SINK .............................................

9 3.1 Response to NRC Position .............................................................

9 3.2 NRC Provided References

...........................................................

10 3.3 Additional Supporting Information

...............................................

21 4.0 SAFETY CLASSIFICATION OF THE TMU SYSTEM ..........................

26 4.1 Response to NRC Position ...........................................................

26 4.2 NRC Provided References

...........................................................

26 4.3 Additional Supporting Information

...............................................

37 5.0

SUMMARY

AND CONCLUSION

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37

6.0 REFERENCES

....................................................................................

38 License Basis Evaluation

-CGS TMU System 1.0 PURPOSE The purpose of this license basis evaluation is to provide an Energy Northwest (EN) position paper that responds to specific concerns raised by the NRC Resident staff related to the license basis of the Columbia Generating Station Tower Makeup (TMU) and Ultimate Heat Sink (UHS) systems.It was identified that there were apparent inconsistencies in Columbia's license basis for the TMU System. These inconsistencies have led to confusion about the role of the TMU system in support of the UHS. The areas of confusion have led to the following questions:

1. Is Columbia's TMU system considered part of the Ultimate Heat Sink and therefore subject to the operability requirements of the UHS in LCO 3.7.1 or is it a support system for the Ultimate Heat Sink?There are two parts to this question that need to be addressed.

a) Is the TMU system an SSC included within the definition of the UHS?b) If the TMU system is considered within the definition of the UHS, then must it meet single failure criterion to support operability of the UHS?2. Should the TMU system be considered "safety related" and should 10 CFR 50 Appendix B quality requirements apply?The position provided by the NRC and the Energy Northwest Evaluation of each of the questions is addressed in sections 3.0 and 4.0 of this report.Section 2.0 provides background information important to a complete understanding of this subject.2 License Basis Evaluation

-CGS TMU System 2.0 BACKGROUND

-NRC IDENTIFIED CONCERN During the course of inspection in the first quarter of 2014, the Resident NRC Inspector identified concerns with work that had previously been performed on Tower Makeup (TMU) pump power supplies (4.16KV non-safety related buses SM-75 and SM-85) in 2012 and 2013 in which the buses were de-energized for maintenance.

While the work was conducted, the NRC noted that the Ultimate Heat Sink (UHS) was not considered inoperable by Energy Northwest staff during the time that the buses'were de-energized when they believed it should have been declared inoperable due to loss of single failure protection.

It was shared by the resident inspector that initial discussions with the Technical Specification Branch in NRR suggested that operability should have been considered however, more information was needed to finalize that conclusion.

After conducting further research the resident inspector identified inconsistencies in Columbia's Licensing Basis documents which led to further concerns about how the TMU system was classified (safety related or non-safety related).

This has led to two major concerns expressed by the resident inspectors as discussed in section 3.0 and 4.0 of this report.2.1 Safety Assessment The Columbia Generating Station TMU system continues to meet all applicable regulatory requirements.

It has been operated and maintained in a manner to ensure availability for the UHS in the event of a tornado.The probability of a smart tornado with sufficient magnitude impacting both ponds of the UHS and thereby impacting its ability to perform its safety function is very low. Columbia's FSAR Section 2.3.1.2.1.3 provides the probability of a tornado at the site of 6 x 10-6 events/year.

The probability of a tornado causing a missile to destroy both spray rings or to travel over both spray ponds and remove substantial volume is obviously much less.Although the TMU system may be classified by Energy Northwest as not safety related, it has been treated as "important to safety." This is reflected in the system design, operation and maintenance.

Based on this, there is no impact on the health and safety of the public while resolving the issues presented in by the NRC for resolution in the Task Interface Agreement (TIA).2.2 TMU Design, Operation and Maintenance System Design: The TMU system provides makeup water to the plant from the Columbia River.The system consists of three 50% capacity pumps (for Circ Water makeup)located in a pumphouse at the river which pump water through approximately 3.5 3 License Basis Evaluation

-CGS TMU System miles of buried piping to Columbia at a design flow up to 25,000 gpm to maintain level in the spray ponds and cooling tower basins.The system is designed with two divisions of power from safety related buses which are capable of being powered by the emergency diesel generators in case of a loss of off-site power. TMU pump A and B are powered respectively from Division 1 and 2 buses. TMU pump C may be powered from either division.

The entire system has been designed to be protected from tornado missiles.System Operation:

During normal operation, the TMU System supports the UHS with makeup for normal losses due to evaporation and drift. The TMU system is used primarily to provide makeup to the circulating water (CW) system to replace water lost via the cooling towers.In the event that all TMU capability to supply makeup water to the CW system is lost during normal plant operation, abnormal procedure ABN-TMU requires a rapid power reduction followed by a reactor scram.The 2 spray ponds provide for a minimum of 30-day cooling without makeup. In the event that both sets of spray headers become damaged (e.g., from a tornado missile), abnormal procedure ABN-WIND provides guidance on how to provide cooling for the spray ponds using a feed and bleed method with the TMU (feed)and CW (bleed) systems.System Maintenance:

Maintenance on the system is scheduled divisionally, such that one division of power to the TMU system is always available and protected.

While a division of power is under maintenance, TMU pump C will typically be aligned to the unaffected division to ensure two pumps are available for makeup. The TMU System is in scope for Maintenance Rule (10 CFR 50.65). Corrective maintenance is prioritized based on the system being in scope for Maintenance Rule.2.3 Dates of Significance The following dates should be used as reference points throughout the discussions provided: August 10, 1971 -Submission of Application for Construction Permit March 19, 1973 -Construction Permit Issued for Hanford 2 March 15, 1977 -Initial Submittal of Final Safety Analysis Report (FSAR) for Application of Operating License for WNP-2 March 1982 -Safety Evaluation Report for WNP-2 (NUREG-0892)

Issued 4 License Basis Evaluation

-CGS TMU System August 1982 -Supplement 1 December 1982 -Supplement 2 May 1983 -Supplement 3 December 1983 -Supplement 4 April 1984 -Supplement 5 December 20, 1983- Operating License Issued for WNP-2 (Note: FSAR Amendment 33 was in effect at time of License issuance)2.4 Changes of Company and Plant Names As noted above, over 40 years has passed since the time of the original application for a construction permit. Since then both the company and plant have undergone name changes: Original Company Name: Washington Public Power Supply System (WPPSS)Current Company Name: Energy Northwest Original Plant Name: Hanford 2 Other Plant Name: Washington Nuclear Project 2 (WNP-2)Current Plant Name: Columbia 2.5 Historical License Basis for the TMU System Most, if not all, of the individuals involved in the early discussions surrounding the permitting and licensing of Columbia no longer work in the industry or with the NRC. Regardless, an effort was undertaken by EN staff to identify and evaluate the license basis for Columbia's TMU system. The results are summarized below. This effort involved looking into the following:

• Applicable regulatory requirements, associated regulatory guides, and endorsed industry documents* Regulatory correspondence (NRC, EN, and other utilities)

• Columbia's Preliminary Safety Analysis Reports (PSAR)* Numerous versions of Columbia's Final Safety Analysis Report (FSAR)* NRC safety evaluation report for Columbia's initial and renewed operating licenses NUREG-0892 and NUREG-2123

• Early TMU and UHS design drawings and system related documents* Internal memo's generated by construction contractor Burns and Roe* NRC positions (e.g., TIAs) on non-safety related systems and application of single failure protection requirements 5

License Basis Evaluation

-CGS TMU System This information was then used to capture the specific license basis for Columbia's TMU system. As specified in 10 CFR 54.3, the definition of "Current License Basis" consists of the following:

• The set of NRC requirements applicable to a specific plant, and* A licensee's written commitments for ensuring compliance with and operation within applicable NRC requirements, and* The plant-specific design basis (including all modifications and additions to such commitments over the life of the license) that are docketed and in effect.In looking into the first attribute of this definition (NRC requirements), the only regulations of considerations to the TMU system were 10 CFR 50 Appendix B, and 10 CFR 50 Appendix A, General Design Criteria (GDC) 2.10 CFR 50 Appendix B states in part: Nuclear power plants and fuel reprocessing plants include structures, systems, and components that prevent or mitigate the consequences of postulated accidents that could cause undue risk to the health and safety of the public. This appendix establishes quality assurance requirements for the design, manufacture, construction, and operation of those structures, systems, and components.

The pertinent requirements of this appendix apply to all activities affecting the safety-related functions of those structures, systems, and components; these activities include designing, purchasing, fabricating, handling, shipping, storing, cleaning, erecting, installing, inspecting, testing, operating, maintaining, repairing, refueling, and modifying.

A search through the license basis for the application of Appendix B to portions of the TMU system reveals that Appendix B (Quality Class 1) requirements were imposed only on "tornado protection" features of the TMU system. These include the TMU pumphouse and the soil covering TMU system buried piping and cabling. The safety classification for the TMU system as documented in Columbia's FSAR and accepted by the NRC in NUREG-0892 is class G (General) which is equivalent to non-safety related. (Reference NUREG-0892 section 3.2, FSAR Table 3.2-1, and WPPSS letter GC2-74-28 to NRC dated February 27, 1974)6 License Basis Evaluation

-CGS TMU System With regard to the application of 10 CFR 50 Appendix A GDC 2, it is only used in license basis documents in terms of the UHS design. 10 CFR 50 Appendix A GDC 2 states: Criterion 2-Design bases for protection against natural phenomena.

Structures, systems, and components important to safety shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss of capability to perform their safety functions.

The design bases for these structures, systems, and components shall reflect: (1) Appropriate consideration of the most severe of the natural phenomena that have been historically reported for the site and surrounding area, with sufficient margin for the limited accuracy, quantity, and period of time in which the historical data have been accumulated, (2)appropriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena and (3) the importance of the safety functions to be performed.

It was determined early on in the licensing process for Columbia Generating Station (then Hanford 2) that tornado events can impact the function of the spray rings in each of the two ponds (i.e., by tornado missiles) or else remove volume from the two ponds. Both of these postulated events impact the UHS' capability to perform its specified safety function under a design basis tornado. As stated previously, Columbia's FSAR Section 2.3.1.2.1.3 provides the probability of a tornado at the site of 6 x 10-6 events/year.

The probability of a tornado causing a missile to destroy both spray rings or to travel over both spray ponds and remove substantial volume would be much less.However, in order for the UHS to meet GDC-2 requirements for these very unlikely events, Energy Northwest proposed relying on the non-safety related TMU system to provide makeup if necessary as a source of cool water to the UHS ponds. The TMU system was provided with tornado protection (i.e., tornado resistant pumphouse and protection of underground power cables and piping).This position was accepted by the NRC staff. Thus the TMU system now becomes a support system to the UHS only in the event of a tornado. (Reference NUREG-0892 section 9.2.5 and 9.4.6, FSAR section 3.3.2.3, 9.2.5, and 9.4.12)It should be noted that GDC 2 requirements do not impose single failure protection criteria.

The TMU system was never required to meet "single failure" protection as defined in 10 CFR 50 Appendix A which requires both active and passive single failure protection.

In addition, nowhere in NUREG-0892, Columbia's FSAR, or regulatory correspondence was single failure protection of the TMU system credited for meeting any regulatory requirement.

It is recognized that the UHS must have single failure protection to meet GDC-44 requirements.

However, the NRC approved definition of the UHS does not include the TMU system (Reference Technical Specification Amendment 52).7 License Basis Evaluation

-CGS TMU System As will be shown in the responses described in Section 3.0 and 4.0 of this report, the TMU system license basis is simply as follows:* 10 CFR 50 Appendix B requirements were only imposed on the "tornado protection" features of the TMU supporting structures (pumphouse and soil).0 The TMU system is only needed to support the UHS during a design basis tornado. As a support system it allows the UHS to meet GDC-2 requirements.

• The TMU is not required to have single failure protection to meet any regulatory requirements.

Details of Columbia's TMU system can be found in all of the following sections of the initial Licensing Basis Documents:

Columbia FSAR (Amendment 33)Section 1.2, General Plant Description 2.2, Nearby Industrial Transportation and Military Facilities 2.4, Hydrology Engineering 3.1, Conformance with NRC General Design Criteria 3.2, Classification of Structures Components and Systems 3.3, Wind and Tornado Loading 3.5, Missile Protection 3.8, Design of Seismic Category I Structures 8.3, Onsite Power Systems 9.2, Water Systems 9.4, Heating, Ventilating, and Air Conditioning Systems 10.4, Other Features of Steam and Power Conversion System FSAR Appendix C, Compliance with Regulatory Guides NRC SER (NUREG-0892)

Section 1.2, General Plant Description 1.9, License Conditions 2.2, Nearby Industrial Transportation and Military Facilities 2.4, Hydrology Engineering 2.5, Geology, Seismology, and Geotechnical Engineering 3.2, Classification of Structures, Systems, and Components 3.5, Missile Protection 3.6, Protection Against Dynamic Effects Associated with the Postulated Rupture of Piping 3.10, Seismic and Dynamic Qualification of Seismic Category I Mechanical and Elect (NUREG-0892 Supplement 4)9.2, Water Systems 9.2, Water Systems (NUREG-0892 Supplement 1)9.4, Heating, Ventilating, and Air Conditioning Systems 10.4, Other Features of Steam and Power Conversion System I 8 License Basis Evaluation

-CGS TMU System 3.0 DEFINITION OF THE ULTIMATE HEAT SINK 3.1 Response to NRC Position With regard to the TMU system's role in the operability of the UHS, the question raised by the resident inspector is summarized as follows: "Is Columbia's TMU considered part of the Ultimate Heat Sink or is it a support system for the Ultimate Heat Sink and should the operability of the UHS in LCO 3.7.1 apply to it?" The position of the resident inspector with regard to this question that was communicated to Energy Northwest Licensing staff is summarized as follows: The TMU system is an SSC included within the definition of the UHS and therefore a loss of single failure protection of TMU results in the UHS being inoperable.

This position is based on references provided to Energy Northwest listed in section 4.2 below as well as the associated arguments.

Energy Northwest does not agree with this conclusion.

It is Energy Northwest's position that the TMU system is a support system for the UHS and only necessary to support UHS operability in the event of a tornado.A loss of single failure protection for this support system does not impact UHS operability for a tornado event and therefore does not require the UHS to be declared inoperable whenever the TMU is vulnerable to a single failure (e.g., a division of power removed for maintenance).

An Energy Northwest response is provided to each of the references provided to the Energy Northwest staff.9 License Basis Evaluation

-CGS TMU System 3.2 NRC Provided References 3.2.1 Washington Public Power Supply System (JJ Stein) letter to NRC (A. Giambusso), Ultimate Heat Sink, dated February 27, 1974 In the letter referenced above the following statement was made which reveals the TMU system as part of the UHS: The systems which act as an Ultimate Heat Sink on WNP-2 are shown on the attached sketch labeled Figure 1.Figure 1 from the letter is depicted below: 14AX0 Uri MPh1o'do 10 License Basis Evaluation

-CGS TMU System Energy Northwest Response to Reference 3.2.11: The figure provided in the above mentioned letter was an early simplified depiction of the UHS that also included the Standby Service Water (SW), Tower Makeup (TMU), and the Circulating Water (CW) systems.Since that time, the depiction of the UHS had changed. For example, in 1982 when NUREG-0892 was issued, the UHS and SW system was depicted differently.

Figure 2.6 on page 2-19 of NUREG-0892 was used to depict the UHS and SW systems below. Note that it does not include the TMU or CW systems.Figure 2.6 Simplified schematic of ultima te heat sink standby service water and spray systems Furthermore, as documented in section 9.2.5 of NUREG 0892, the UHS was more specifically defined as follows: The UHS consists of two separate and redundant spray ponds and standby service water systems and their associated piping. Each spray pond has a ring header for spray trees.In addition, Section 9.2.5.2 of FSAR Amendment 33 (initially licensed version)defined the UHS as follows: The ultimate heat sink consists of two concrete ponds with redundant pumping and spray facilities.

Lastly, on April 4, 1988, the NRC concurred with the Energy Northwest definition of the Ultimate Heat Sink in Technical Specification (TS) Amendment 52 (ML022060624) as documented in the NRC safety evaluation.

The change and the abstract from the safety evaluation are documented below: Amendment 52 revised the definition of the ultimate heat sink as stated in Limiting Condition for Operation (LCO) 3.7.1.3: 11 License Basis Evaluation

-CGS TMU System ULTIMATE HEAT SINK LIMITING CONDITION FOR OPERATION 3.7.1.3 The ultimate heat sink consisting of two separate spray ponds with redundant pumping and spray facilities shall be OPERABLE with: Amendment 52 safety evaluation:

The licensee also requested that the definition of the ultimate heat sink, as succinctly expressed in the lead sentence of Technical Specification 3.7.1.3, be revised to be consistent with the wording in the WNP-2 Final Safety Analysis Report Section 9.2.5.2. This change in wording does not result from a design change nor does it authorize a design change. Furthermore, it does not alter the staff's understanding of the configuration of the ultimate heat sink. The staff finds the wording change proposed by the licensee acceptable.

This language is consistent with the existing Columbia TS and can be found in the Technical Specifications Bases for TS 3.7.1.3.2.2. NRC letter (K Kniel) to Ecolaire Condenser, Inc. (WE Palmer), Oriented Spray Cooling System Topical Report, dated November 22, 1977 In the above letter, the NRC concluded that the Oriented Spray Cooling System (OSCS) alone was an insufficient design for the UHS. Reference the applicable text below: We cannot approve the OSCS as the only plant ultimate heat sink.However, the OSCS could be used as an alternate cooling source as part of an ultimate heat sink. The other part of the heat sink would have to be protected against tornado missiles, meet single failure criteria, and be designed to quality group "C". This other part need not be designed to seismic category I requirements.

As documented in Columbia safety evaluation report (NUREG-0892) section 2.4.5 and Columbia Final Safety Analysis Report (FSAR) Section 9.2.5.3, an Ecolaire oriented spray cooling system (OSCS) is utilized at Columbia for cooling the water inventory of the UHS.Energy Northwest Response to Reference 3.2.2 As stated previously in response to reference 3.2.1, the definition of the UHS was established in the initial FSAR (Amendment

33) and further supported by the NRC safety evaluation associated with Amendment 52 of the TS in 1988. The letter referenced in 3.2.2 was part of early dialogue by the NRC with a vendor on the design of the UHS but in of itself does not establish the definition of the Columbia UHS.12 License Basis Evaluation

-CGS TMU System The subject of these discussions was not Columbia's UHS but rather a proposed system to be used at Columbia.

NUREG-0892 documents conclusions that do not involve altering the definition of the UHS because of the OCSC. For example, NUREG-0892 Section 2.4.5 Safety-Related Water Supply -Ultimate Heat Sink (UHS) contains the following:

The safety-related water supply for the WNP-2 plant is provided by two seismic Category I spray ponds designed to contain a 30-day supply of cooling water for safe shutdown of the plant during accident conditions.

The two concrete ponds incorporate Ecolaire Condenser Inc. -oriented spray cooling systems. Each pond is 250 feet square and contains a useable volume of 6.25 x 10(6) gal...Based on its review of the information provided by the applicant and its own independent analyses using both conservative and reasonable parameters, the staff concludes that the WNP-2 ultimate heat sink meets the criteria of Regulatory Guide 1.27, and that its hydrologic and thermal performance meets the requirements of GDC 44.In addition, NUREG-0892 Section 9.2.5 Ultimate Heat Sink contains the following text which treats the plant makeup water system as a separate support system for the UHS in the event of a tornado (emphasis added): The ultimate heat sink (UHS) provides cooling water to the standby service water systems during accident conditions for cooling of essential plant auxiliary components.

The UHS consists of two separate and redundant spray ponds and standby service water systems and their associated piping.Each spray pond has a ring header for spray trees...The concrete spray ponds are designed to seismic Category I requirements and are designed to withstand the effects of floods and tornadoes.

The spray trees are not tornado resistant.

However, should a larme number of the spray units be damaged, cooling would still be available by way of the tornado-protected, plant makeup water system, which can be used to supply water to the ponds from the Columbia River. Thus, the requirements of GDC 2, and the guidelines of Regulatory Guide 1.29 are satisfied.

Based on the above, the staff concludes that UHS meets the requirements of GDC 2, 44, 45 and 46, with respect to protection against natural phenomena, cooling water, inservice inspection and functional testing, and the guidelines of Regulatory Guides 1.27 and 1.29, with respect to seismic classification and the capability to remove sufficient decay heat to maintain plant safety.The system is, therefore, acceptable.

13 License Basis Evaluation

-CGS TMU System 3.2.3 FSAR Amendment 33 Section 3.3.2.3 (December 1983)Amendment 33 of the FSAR was the version in effect at the time of initial licensing of Columbia (formerly WNP-2). In section 3.3.2.3 of this version the following definition for the ultimate heat sink was provided: The makeup water system and the standby service water system, including the spray ponds, act as the ultimate heat sink.This text was later modified by Licensing Document Change Notice (LDCN)94-058 approved on July 22, 1994 and then eliminated altogether in LDCN 97-121 approved on May 26,1998.Energy Northwest Response to Reference 3.2.3 Section 3.3.2.3 of FSAR Amendment 33 contained an incorrect and inconsistent statement that was later identified and corrected.

In 1994 it was identified as being inconsistent with the understanding of the UHS and SW systems as defined and treated in other regulatory documents (RG 1.27 and NUREG 0800). It was also recognized that it was inconsistent with the definition previously established in other sections of the FSAR and the Technical Specifications that didn't include the TMU system. Therefore, LDCN-94-058 simply corrected the inconsistency.

In 1997, it was deemed that the language in section 3.3.2.3 was repetitious to language in section 9.2.5.3 and therefore the language was deleted from this one location.3.2.4 WPPSS Response to NRC FSAR Review Question 10.24 (Amendment 5)In the WPPSS response to question 10.24, WPPSS declared that the UHS design provisions include continuous water make-up capability (see below).0. 010.24 RSP (9.2.5)We require that you protect the sprays in the ultimate heat sink from the effects of tornados and tornado missiles.Response: As discussed in 3.3.2.3, the WNP-2 UHS design provides for continuous water make-up to the spray ponds in the event that both the spray systems are rendered inoperable due to tornado missiles.

Therefore, the sprays are not required to be protected from the effects of tornado missiles since an 14 License Basis Evaluation

-CGS TMU System alternate UHS operating mode (continuous Make-up) is available which is protected from the effects of tornadoes and tornado missiles.Energy Northwest Response to Reference 3.2.4 Energy Northwest acknowledges that TMU is capable of providing continuous make-up to support the alternate UHS operating mode (feed and bleed as opposed to use of sprays) in the event that a tornado renders both pond spray systems inoperable due to tornado missiles.

Therefore, Energy Northwest acknowledges that the TMU system is required as a support system for the UHS in the event of a tornado in order for the UHS to meet General Design Criteria (GDC) 2 requirements.

3.2.5 WPPSS Response to NRC PSAR Review Question 10.8 (PSAR Amend 12)In the above referenced response, WPPSS indicated that TMU was designed to meet single active failure protection during a tornado (see below).QUESTION 10.8 (June 12, 1972)Discuss the ability of the spray pond to perform its safety function in the event of design basis tornado or earthquake.

Discuss the possibility of tornado missiles or tornado or earthquake caused obstructions rendering the ultimate heat sink unavailable.

ANSWER... The river water pump house is designed to withstand the design basis tornado and the pumps within are supplied power from the plant standby power system via underground cabling. A redundant power supply is provided to protect against single failure (as defined in AEC General Design Criteria).

No single active failure can prevent the river water pumping system from providing water to replace water lost during high wind conditions.

Energy Northwest Response to Reference 3.2.5 Energy Northwest acknowledges that TMU is required as a support system for the UHS in the event of a tornado. It was designed with single "active" failure protection features.

However, it is not designed to protect against single"passive" failures.

The implication from the NRC comments is that since the TMU system has a single active failure protection design, the TMU system must also be part of the UHS and thus subject to the single failure protection requirements of GDC-44.However, Energy Northwest disagrees.

Single active failure protection of the TMU system was a design feature that provided additional margin of safety 15 License Basis Evaluation

-CGS TMU System during the highly unlikely event of a tornado at the station and the equally unlikely probability that both spray header rings were destroyed by tornado missiles.The TMU system was never required to satisfy GDC-44 single failure protection requirements.

Note that GDC-44 does not make the distinction that protection should be for single "active" failures but rather uses the all-encompassing "single failure" protection requirement.

Also note that the definition from 10 CFR 50 Appendix A for the broader "single failure" term clearly includes the requirement for protection against both single "active" and single "passive" failures: Fluid and electric systems are considered to be designed against an assumed single failure if neither (1) a single failure of any active component (assuming passive components function properly) nor (2) a single failure of a passive component (assuming active components function properly), results in a loss of the capability of the system to perform its safety functions.

It is Energy Northwest's position that single failures (active or passive) in addition to the multiple failures assumed to occur during a tornado event do not need to be considered in supporting the operability of the UHS during a tornado event.Therefore, potential single failures that could result in the complete loss of the TMU system used as an emergency makeup source to the UHS during a tornado do not need to be considered in determining the operability of the ultimate heat sinks as it relates to tornado events.For example, should one division of power provided to the TMU system be taken out of service for maintenance leaving only one division of power to the TMU system, the UHS is not considered inoperable since no additional single failures are presumed in addition to a tornado, loss of offsite power, and loss of both pond spray headers.A more complete basis for why Energy Northwest does not assume single failure protection in TMU support of the UHS is provided below: Basis: " The Columbia FSAR does not assume an additional single failure occurring simultaneously with the assumed tornado event failures." NRC Regulatory Guide 1.27, Ultimate Heat Sink for Nuclear Power Plants, Revision 2 does not require that the Ultimate Heat Sink be designed to withstand a tornado event combined with a simultaneous single failure." GDC-2, Design Bases for Protection Against Natural Phenomena, does not require single failure protection along with the assumed natural phenomena." Previous NRC positions have concluded that an additional single failure does not have to be considered to occur simultaneously with external events.16 License Basis Evaluation

-CGS TMU System* Previous NRC positions have concluded that single failure proof design capability for non-Technical Specification related SSCs are not required for supporting operability of Technical Specification related SSCs.Supporting Information:

A. Columbia FSAR Tornado events are analyzed in the Columbia, FSAR section 3.3.2. In addition, as tornado events relates to the ultimate heat sink, more discussion is provided in FSAR section 9.2.5. Nowhere is it documented or assumed in the FSAR that a single failure occurs in addition to the multiple failures caused by the tornado itself (e.g., loss of offsite power, loss of all inventory in both spray ponds, etc.).As noted in FSAR Table 3.2-1 note 31, the TMU system is protected from tornado hazards such that the tornado will not have a direct impact of the capability of the TMU system to provide the necessary makeup.B. NRC Regulatory Guide 1.27, Ultimate Heat Sink for Nuclear Power Plants, Rev 2 Columbia FSAR section 1.8 states Columbia's compliance with revision 2 of NRC RG 1.27. This Reg Guide describes four separate events that the ultimate heat sink (UHS) must be able to withstand.

It does not require the UHS to be capable to withstand a single failure in addition to a severe natural phenomenon.

As noted in section C.2 of NRC RG 1.27, the following are the design requirements regarding the capability of the ultimate heat sink: 2. The ultimate heat sink complex, whether composed of single or multiple water sources, should be capable of withstanding, without loss of the sink safety functions specified, in regulatory position 1, the following events: a. The most severe natural phenomena expected at the site, with appropriate ambient conditions, but with no two or more such phenomena occurring simultaneously, b. The site-related events (e.g., transportation accident, river diversion) that historically have occurred or that may occur during the plant lifetime, c. Reasonably probable combinations of less severe natural phenomena and/or site-related events, d. A single failure of manmade structural features.17 License Basis Evaluation

-CGS TMU System This Reg Guide treats these as four separate events. Only item 2.c points to a combination of lesser versions of events 2.a and 2.b, but there are no other combinations considered in the list of events. Only 2.d specifies single failure protection; however it does not require it in addition to natural phenomena.

C. GDC-2, Desigqn Bases for Protection Against Natural Phenomena Unlike GDC-44, Cooling Water, which requires single failure protection during normal operation or design basis accidents, GDC-2 establishes no design requirement to consider single failure protection during a natural event.D. Previous NRC Position -Single Failure Criteria and Coincident External Event Prairie Island Nuclear Generating Plant, Unit 2 -Response to TIA-2001 "Design Basis Assumptions for Ability of Prairie Island, Unit 2, Emergency Diesel Generators to Meet Single Failure Criteria for External Events" September 4, 2003. (ML032040412)

Similar to GDC-44, GDC-1 7, Electric power systems, imposes single failure requirements on the design of the onsite electric power supplies (i.e., emergency AC power system). However, after reviewing Prairie Island's FSAR, the GDCs, and the Safety Evaluation Report for the station, the NRC made the following conclusion (emphasis added): In summary, neither the GDCs, the FSAR, or the staff's September 28, 1972, safety evaluation, specify that the emergency AC power system is required to meet single failure criteria coincident with an external event.Even knowing full well that GDC-1 7 imposes single failure criteria on emergency AC power systems, the NRC staff still concluded that for the purposes of an external event, the GDCs do not impose the requirement to meet a coincident single failure.E. Previous NRC Position -Single Failure Criteria for non-Tech Spec SSCs In NRC Letter from NRC (Douglas V. Pickett Senior Project Manager, Section 2) to Guy G. Campbell (Vice President

-Nuclear, Perry), "Application of Generic Letter 80-30 Guidance to an Inoperable Non-Technical Specification Support Subsystem" (ML020950074), the following NRC position was communicated (emphasis added): In some designs, the non- TS support system has two redundant 100 percent capacity subsystems, each capable of supporting both TS trains.Loss of one support subsystem does not result in a loss of support for either train of TS equipment.

Both TS trains remain operable, despite a loss of support function redundancy, because the TS definition of 18 License Basis Evaluation

-CGS TMU System operability does not require a TS subsystem's necessary support function to meet the single-failure design criterion.

3.2.6 NUREG-0892, WNP-2 Safety Evaluation Report (SER) Section 9.2.5 The NRC SER concludes that Columbia (formerly WNP-2) meets the requirements of GDC-44 for the UHS:..Based on the above, the staff concludes that UHS meets the requirements of GDC 2, 44, 45, and 46, with respect to protection against natural phenomena, cooling water, inservice inspection and functional testing, and the guidelines of Regulatory Guide 1.27 and 1.29, with respect to seismic classification and the capability to remove sufficient decay heat to maintain plant safety. The system is, therefore, acceptable.

Energy Northwest Response to Reference 3.2.6 Energy Northwest agrees that the design of Columbia's UHS meets the requirements of GDC-44 as documented and described in NUREG-0892.

However, it is EN's position that the TMU system is only used as a support system to allow the UHS to meet GDC-2 requirements and not GDC-44. Both the Columbia FSAR and NUREG-0892 only referred to the TMU system in terms of GDC-2 support. For example: In section 9.2.5 of NUREG-0892 The concrete spray ponds are designed to seismic Category I requirements and are designed to withstand the effects of floods and tornadoes.

The spray trees are not tornado resistant.

However, should a large number of the spray units be damaged, cooling would still be available by way of the tornado-protected, plant makeup water system, which can be used to supply water to the ponds from the Columbia River. Thus, the requirements of GDC 2, and the guidelines of Regulatory Guide 1.29 are satisfied.

In section 9.4.6 of NUREG-0892 the following text is found: The only natural design-basis event that would significantly reduce the water in the spray ponds is a tornado. Thus, the makeup water system is only required to operate durinq a tornado (refer to Section 9.2.5 of this SER for a discussion of the spray ponds). Therefore, the portion of the ventilation system providing air to the makeup water transformers is tornado and tornado-missile protected.

Thus, the requirements of GDC 2 and the guidelines of Position C.2 of Regulatory Guide 1.29 are met. No other GDC are applicable.

19 License Basis Evaluation

-CGS TMU System In Section 9.4.11 of NUREG-0892 the following text is found... The makeup water pumps are not needed in a seismic event but are needed during a tomado (refer to Section 9.2.5 of this SER). Therefore, the makeup water pump house HVAC is nonseismic Category I but is tornado protected.

Thus, the requirements of GDC 2 are met.It is evident from the language in NUREG-0892 that the TMU system is only recognized as being needed by the UHS to satisfy GDC 2 criteria.

GDC-44 is met through the use of the Standby Service Water (SW) System and the UHS as defined in the Columbia FSAR and approved in TS Amendment 52.3.2.7 General Design Criteria (GDC) 44, Cooling Water GDC-44 requires single failure protection for ensuring the safety function of the cooling water system can be accomplished.

See below: Criterion 44 -Cooling water. A system to transfer heat from structures, systems, and components important to safety, to an ultimate heat sink shall be provided.

The system safety function shall be to transfer the combined heat load of these structures, systems, and components under normal operating and accident conditions.

Suitable redundancy in components and features, and suitable interconnections, leak detection, and isolation capabilities shall be provided to assure that for onsite electric power system operation (assuming offsite power is not available) and for offsite electric power system operation (assuming onsite power is not available) the system safety function can be accomplished, assuming a single failure.Energy Northwest Response to Reference 3.2.7 Discussion on the application of GDC-44 and single failure protection to the TMU system is provided in response to references 3.2.5 and 3.2.6 of this position paper.3.2.8 FSAR Amendment 33 Section 9.4.12.3 (December 1983)Amendment 33 of the FSAR was the version in effect at the time of initial licensing of Columbia (formerly WNP-2). In section 9.4.12.3 of this version the following single failure protection design is discussed:

.. The heating and ventilating systems provided in the make-up water pump house incorporates the following safety features to ensure that a single component failure will not prevent the system from performing its operational function.20 License Basis Evaluation

-CGS TMU System a. Two full capacity air handling units are provided for the electrical equipment area and two full capacity fan coil units are provided for the make-up pump area; therefore, failure of any one unit will not effect system operation.

b. The redundant HVAC equipment is powered from different divisions of the emergency diesel generator buses; therefore, failure of any one bus will affect only one train of ventilating equipment.

This text still exists in the current version of the FSAR.Energy Northwest Response to Reference 3.2.8 FSAR section 9.4.12.3 provides details about the robust design of the heating and ventilating systems used to support cooling in the TMU pump house. It does not state nor imply that this design feature is present in order to meet any GDC requirements.

3.3 Additional Supporting Information In addition to the references already provided ion response to the NRC concerns in Section 3.2 of this position paper, Section 3.3.1 of this position paper provides other references regarding the definition of the UHS. Similarly, section 3.3.2 of this position paper provides additional references regarding the TMU as only a support system for the UHS during tornado events to support the UHS meeting GDC 2 design criteria alone.3.3.1 TMU Definition References 3.3.1.1 FSAR Amendment 33 The following references (emphasis added) were contained within the version of the FSAR that was in effect when the plant was licensed (Amendment 33).They demonstrate consistency with the Energy Northwest position on the definition of the UHS which treats the TMU system as a separate system:* FSAR Section 1.2.2.12.3 Ultimate Heat Sink Two sWray ponds that serve as the ultimate heat sink conservatively have a combined equivalent storage of thirty days, assuming no makeup and maximum evaporation and drift losses." FSAR Section 2.2.3.1 Determination of Design Basis Events The Seismic Category I spray ponds provide for 30 day cooling without makeup." FSAR Section 2.4.8 Cooling Water Canals and Reservoirs 21 License Basis Evaluation

-CGS TMU System The two spray ponds located southeast of the reactor building (see Figure 2.1-4), designed as Seismic Category I structures...

The spray ponds are the ultimate heat sink for normal reactor cool down and are the ultimate heat sink for emergency cooling." FSAR Section 2.4.11.5 Plant Requirements Makeup to the plant cooling towers and spray ponds comes from the Columbia River. Should this capability be lost, the cooling load is taken over by the spray ponds. These ponds have sufficient capacity to provide shutdown cooling water for thirty days without makeup.* FSAR 3.1.2.4.15.1 Evaluation Against Criterion 44 The safety related cooling water system is the standby service water system, which supplies the RHR System, HPCS System, and the HVAC essential systems.The redundant standby service water systems are open loop systems which transfer heat from structures, systems and safety related components to the ultimate heat sink.The ultimate heat sink consists of two man made Seismic Cateaory I spray ponds and is designed to withstand extreme natural phenomena* FSAR Section 9.2.5.1 (See Appendix A for additional details)The ultimate heat sink, a spray pond system, supplies cooling water to remove heat from all nuclear plant equipment that is essential for a safe and orderly shutdown of the reactor and to maintain it in a safe condition* FSAR Section 9.2.5.2 (UHS) System Description Following any event that would prevent the use of the plant cooling towers, the heat rejection duties are transferred to the spray ponds. The ultimate heat sink consists of two concrete ponds with redundant pumping and spray facilities.

The pond and pumphouse arrangements are shown on Figure 9.2-11. The ponds and pumphouses are designed to Seismic Category I requirements.

Standby service water (SW) loop A draws water from pond A, cools the Division I equipment required for safe shutdown, and discharges through the spray ring in pond B for heat dissipation.

Similarly, SW loop B draws water from pond B, cools Division II equipment, and discharges through the spray ring in pond A.The HPCS SW system draws water from pond A, cools Division Ill and discharges without spray into pond A. A syphon between the ponds allows for water flow from one pond to the other...22 License Basis Evaluation

-CGS TMU System The ultimate heat sink consists of two concrete ponds with redundant pumping and spray facilities...

Although the pond is not used for cooling during normal operation, some small losses are to be expected due to normal evaporation from the surface and occasional blowdown needed to maintain water chemistry.

The ponds can also be supplied directly from the plant makeup water pump s.3.3.1.2 NUREG-0892, Safety Evaluation The following references (emphasis added) were contained within NUREG-0892. They demonstrate consistency with the Energy Northwest position on the definition of the UHS which treats the TMU system as a separate system:* NUREG-0892 Section 2.5.4.1, General The seismic Category I UHS system consists of two concrete spray ponds, two standby service water (SSW) pumphouses, and pipelines and conduits between the pumphouses and the power block structures." NUREG-0892 Section 9.2.5, Ultimate Heat Sink The UHS consists of two separate spray ponds and two separate and redundant standby service water systems and their associated piping.* NUREG-0892 Section 9.2.7, Standby Service Water The standby service water system (SSWS) supplies cooling water to the plant from the two spray ponds which serve as the ultimate heat sink (refer to Section 9.2.5 of this SER).3.3.2 TMU Support to the UHS in the Event of a Tornado 3.3.2.1 FSAR Amendment 33 The following FSAR Amendment 33 references demonstrate consistency with the Energy Northwest position that TMU is a support system for the UHS only in the case of a tornado with additional failures.

The FSAR language treats the TMU as a "separate" but important system from the UHS (emphasis added):* FSAR Section 3.3.2.3, Effect of Failure of Structures or Components Not Designed for Tornado Loads The spray pond piping and supports are designed to withstand the effects of the design basis tornado. The piping system cannot be protected from the impact of tornado generated missiles.

In the event of 23 License Basis Evaluation

-CGS TMU System missile damage to one of the pond spray headers, the alternate spray system which is 100% redundant is placed in operation.

In the event that both spray systems are rendered inoperative, the cooling tower makeup water system is placed into operation to provide continuous makeup to the spray ponds with Columbia River water, the temperature of which never exceeds 70 OF. The cooling tower makeup water system is provided with sufficient protection to prevent its loss of function in the event of a design basis tornado passing over the project site.Since the makeup water flow rate exceeds that of the standby service water systems, and since the makeup water temperature is substantially lower than the standby service water system design temperature of 85 OF, the continuous availability of cooling water at a maximum temperature of 70 IF is assured. The method of detection of spray pond header failure and procedures for alternate spray pond usage is described in 9.6.* FSAR Section 3.5.2, Systems to be Protected The TMU system is required for safe shutdown only when both spray ring headers are lost to tornado missiles" FSAR Section 9.2.5.3, (UHS) Safety Evaluation The possibility of a tornado passing over the spray pond and removing a significant amount of water is considered a credible event. For this reason, the makeup water pumphouse is designed to be tornado proof, with all piping and electrical power supply between the plant and the pumphouse underground.

Since it is not credible to assume an earthquake coincident with a tornado, this system need not be Seismic Category I. Two 12,500 gpm plant makeup water pumps are provided, one powered from each emergency diesel generator.

Should pond water be lost due to a tornado, one of these pumps will be started to provide makeup. Makeup supply to the spray ponds is controlled by level switches that automatically open a supply valve to allow gravity drain from the circulating water pump basin to replenish spray pond level when it reaches the makeup setpoint.24 License Basis Evaluation

-CGS TMU System* FSAR Section 9.2.7.2, (Standby Service Water System) System Description The two spray ponds provided are sized to have a combined equivalent stora-ge for at least thirty days of operation, assuming no makeup and maximum evaporation and drift losses. (See 9.2.5).The makeup water system supplies Columbia River water to the cooling towers or spray pond to replace water lost during normal operation due to evaporation and drift." FSAR Section 9.4.12, (Makeup Water Pumphouse Ventilation)

Safety Evaluation In the event of the hypothesized dewaterinq of the standby service water spray ponds due to a tornado, the make-up water pumps may be operated to refill the spray ponds.25 License Basis Evaluation

-CGS TMU System 4.0 SAFETY CLASSIFICATION OF THE TMU SYSTEM 4.1 Response to NRC Position With regard to the safety classification of the TMU system, the question raised by the resident inspector is summarized as follows: "Should the TMU system be considered safety related and should 10 CFR 50 Appendix B quality requirements apply?" The position of the resident inspector with regard to this question that was communicated to Energy Northwest Licensing staff is summarized as follows: Those portions of the TMU system credited for the support of the UHS function during a tornado event should be characterized as safety related.This position is based on references provided to Energy Northwest listed in section 5.2 below as well as the associated arguments.

Energy Northwest does not agree with this conclusion.

It is Energy Northwest's position that the TMU system was always classified as non-safety related and only certain support structures (e.g., TMU pumphouse, soil covering the piping to the UHS, etc.) were loosely characterized as safety related.An Energy Northwest response is provided to each of the references provided to the Energy Northwest staff.4.2 NRC Provided References 4.2.1 10 CFR 50.2 Definitions The definition of "safety related" is found in 10 CFR 50.2: Safety-related structures, systems and components means those structures, systems and components that are relied upon to remain functional during and following design basis events to assure: (1) The integrity of the reactor coolant pressure boundary (2) The capability to shut down the reactor and maintain it in a safe shutdown condition; or (3) The capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to the applicable guideline exposures set forth in § 50.34(a)(1) or § 100.11 of this chapter, as applicable.

26 License Basis Evaluation

-CGS TMU System The TMU system is relied upon to remain functional during and following a tornado (i.e., a design basis event) to assure the capability to shut down the reactor and maintain it in a safe shutdown condition.

Energy Northwest Response to Reference 4.2.1 There are two fundamental concerns with the application of this definition to Columbia's TMU system: 1) the formal definition was established well after Columbia was licensed, and 2) the NRC approved the current safety classification of the TMU system in NUREG-0892 that is not consistent with this definition.

The formal definition for "safety related" was not established by the NRC until 1997, well after Columbia's license was issued in 1983. As documented in the Federal Register, Volume 61, No. 239, dated December 11, 1996, the formal definition of "safety related" was made effective January 10, 1997 when it was included in 10 CFR 50.2. The associated backfit analysis documented in the federal register states the following (emphasis added): XV. Backfit Analysis The NRC has determined that the backfit rule, 10 CFR 50.109, does not apply to this regulation, and, therefore, a backfit analysis is not required for this regulation because these amendments do not involve any provisions that would impose backfits as defined in 10 CFR 50.109(a)(1).

The regulation would apply only to applicants for future nuclear power plant construction permits, preliminary design approval, final design approval, manufacturing licenses, early site reviews, operating licenses, and combined operating licenses.At the time of construction and licensing of Columbia, a formal definition of the terms "important to safety" and "safety related" did not exist, usage of these terms by both the industry and the NRC was inconsistently applied and occasionally used interchangeably.

It was generally accepted that the term"safety related" had a much narrower scope than the term "important to safety".This was reinforced by the NRC's response to two industry related letters as documented by Harold Denton, Director of NRR, in Generic Letter 84-01: I agree that the use of these terms in a variety of contexts over the past several years has not been consistent.

In recognition of this problem /attempted in my 1981 memorandum to NRR personnel to set forth definitions of these terms for use in all future regulatory documents and staff testimony before the .adjudicatory boards. As you are aware, the position taken in that memorandum was that "important to safety" and "safety-related" are not synonymous terms as used in Commission regulations applicable to nuclear power reactors.27 License Basis Evaluation

-CGS TMU System The former encompasses the broad scope of equipment covered by Appendix A to 10 CFR Part 50, the General Design Criteria, while the latter refers to a narrower subset of this class of equipment defined in Appendix A to 10 CFR Part 100 Section VI(a)(1) and, more recently, in 10 CFR 50.49(b)(I).

Based on such a distinction between these terns, it generally has been staff practice to apply the quality assurance requirements of Appendix B to 10 CFR Part 50 only to the narrower class of "safety-related" equipment, absent a specific regulations directing otherwise.

Therefore, it is not reasonable to assume that today's definition for safety related found in 10 CFR 50.2 specifically applied to Columbia's TMU system. In addition, it would not be consistent with the NRC approval of the TMU system safety classification in NUREG-0892.

Section 3.2 of NUREG-0892, Classification of Structures, Systems, and Components, the following text is found (emphasis added)The systems and components important to safety of WNP-2 have been identified in an acceptable manner in FSAR Table 3.2-1. Table 3.2-1, in part, identifies the major components in fluid systems such as--pressure vessels, heat exchangers, storage tanks, pumps, piping, and valves--and mechanical systems--such as cranes, refueling platforms, and other miscellaneous handling equipment.

In addition, the piping and instrumentation diagrams in the FSAR identify the Quality Group classification boundaries of the interconnecting piping and valves. The staff has reviewed Table 3.2-1 and the fluid system piping and instrumentation diagrams and concludes that pressure-retaining components have been properly classified as Quality Group A, B, C, or D components in conformation with Regulatory Guide 1.26, Revision 3.The staff finds this summary list of codes and standards used in the construction of components to be acceptable.

The applicant has also utilized the American Nuclear Society (ANS) Safety Classes 1, 2, 3 and "GENERAL" as defined in ANS-22, "Nuclear Safety Criteria for the Design of Stationary Boiling Water Reactor Plants," in the classification of system components considered by the applicant to be beyond the scope of Regulatory Guide 1.26. Safety Classes 1, 2, 3, and "GENERAL" correspond to the Commission's Quality Group A, B, C and D in Regulatory Guide 1.26 and have been used by the applicant to supplement the Commission's Quality Group classification system. A summary of the relationship of the NRC Quality Group and ANS Safety Classes is shown in Table 3. 1.28 License Basis Evaluation

-CGS TMU System Table 3.1 Relationship between NRC Quality Group and ANS safety classes NRC Quality Group A B C D WNP-2 BWR Safety Class 1 2 3 GENERAL The staff has reviewed the use of ANS Safety Classes in Table 3.2-1 and finds the classification of components to be acceptable.

The staff concludes that construction of the components in fluid systems important to safety in conformance with the ASME Code, the Commission's regulations, and the guidance provided in Regulatory Guide 1.26 and ANS-22; provides assurance that component quality is commensurate with the importance of the safety function of these systems; and constitutes an acceptable basis for satisfying the requirements of GDC 1.With regard to the TMU system and the TMU pumphouse, Amendment 33 of FSAR Table 3.2-1, Equipment Classification, is provided below. Note that the safety class is G (i.e., General) applicable for both which is equivalent to a "non-safety related" system. However, only the TMU pumphouse is documented as meeting Quality Class I requirements.

Note 31 recognizes the TMU system as having tornado protection by virtue of the TMU pumphouse construction and soil covering various portions of the TMU system: Scope of Supply (2)Quality Group Safety Loca- Classifi-Class tion cation (3) (4) (5)Principal Component (1)Quality Seismic Com-Class Category ments (6) (7)44. Circulating Water and Cool-ing Tower Makeup Water Sys-tem(s)(See Figure 10.4-3).1 Piping and valves P G P D II II (31).2 Pumps P G P D II IT.3 Cooling tower fans P G P D II II 47. Buildings.8 Makeup Water Pumphouse N/A G 0 N/A I II (31)31. The makeup water pumphouse is designed to withstand the design basis tornado. The design also considers the possible effects of tornado generated missiles.

The tower makeup water piping, valves, and cabling located underground are provided with adequate earth cover to be resistant to tornado generated missiles or are protected by tornado resistant structures.

29 License Basis Evaluation

-CGS TMU System 4.2.2 Washington Public Power Supply System (JJ Stein) letter to NRC (A. Giambusso), Ultimate Heat Sink, dated February 27,1974 In the letter referenced above the following statement was made by WPPSS: In addition the Cooling Tower Makeup System will be constructed under 10 CFR 50 Appendix B, Quality Assurance Requirements to provide assurance that tornado protection is actually provided.

The Cooling Tower Makeup System is not a Seismic Category I system since seismic protection is provided by the standby Service Water System.Energy Northwest Response to Reference 4.2.2 The letter that is referenced is a summary of a meeting that took place between the NRC and WPPSS (now Energy Northwest) in October 1973. Energy Northwest understood that the Appendix B quality requirements applied to the"tornado protection" aspect of the TMU system (e.g., TMU Pumphouse, soil covering both the piping to the UHS and power cabling to the TMU pumphouse).

Note that the language in the letter points to the intent of the Appendix B application: "to provide assurance that tornado protection is actually provided'.

This was accomplished for the pumphouse and the soil used for covering the piping and cabling.This was further supported in an August 1974 letter from Burns and Roe, the primary architectural engineering firm for WNP-2 (now Columbia) to WPPSS, in which John J. Verdeber, Project Engineering Manager, an attendee at the October 1973 meeting with the NRC makes the following response to comments raised by WPPSS staff: WPPSS Comment Those portions of the makeup water pumphouse required for tornado protection and for operability in providing a source of makeup water should be Quality Class I. This would be consistent with the fact that the river water makeup pumps are provided with emergency power through the buried redundant feeders running from the reactor area to the river water pumphouse.

In addition, we have told the AEC in our letter GC2-74-28 dated February 27. 1974 that "The cooling tower makeup system will be constructed under 1 OCFR50 Appendix B, Quality Assurance requirements, to provide assurance that tornado protection is actually provided." The easiest way of meeting this requirement would be to require all construction in the makeup water pump house to be Quality Class I with no exceptions.

Lacking this, the drawings should be very specific in what work is required to be Quality Class I and what work does not have to meet these requirements.

30 License Basis Evaluation

-CGS TMU System Burns and Roe Response The application of the Q.A. I designation applies only to that portion of the work required to provide tornado protection.

Since this mainly refers to missile protection, only the structure has been classified Q.A. I. This position is consistant with the commitment to the A.E.C.This position communicated by Mr. Verdeber is consistent with the response provided by WPPSS to the NRC in the referenced letter. In addition this position has been further promulgated in the Columbia FSAR Table 3.2-1 (Amendment 33 to the current version).

As documented in response to reference 5.2.1 above, this position was accepted by the NRC in section 3.2 of NUREG-0892.

4.2.3 WPPSS Response to NRC FSAR Review Question 10.12 (Amendment 33)In the WPPSS response to question 10.12, WPPSS identified what items in the turbine building have safety related functions (see below).0. 010.012 Provide the results of your evaluation of the jet impingement forces and the environmental effects, including pressure, temperature, humidity, and flooding, resulting from a postulated failure of the main steam and main feedwater systems in the Turbine Building.

This evaluation should only address those safety-related components, systems and structures, if any, in (or immediately adjacent to) the Turbine Building (e.g., the walls of the Auxiliary Building)Response: It has been determined that the only items with safety-related functions in the Turbine Building are some RPS sensor inputs from the Main Steam System, MSIV isolation logic inputs from the Main Steam System, and the Tower Make-up Transformers located in the basement of the Turbine Building which are required to function only for the Design Basis Tornado event.Energy Northwest Response to Reference 4.2.3 This is an example of a misuse of the "safety-related" terminology.

As noted in GL 84-01, the subset of SSCs considered to be safety-related were those credited in 10 CFR 100 Appendix A Sections IV(a)(1) and IV(a)(2).

The requirements of 10 CFR 100 outlined what SSCs were required in the event of a safe shutdown earthquake (SSE) and operating basis earthquake (OBE). The TMU system is not now nor has it ever been credited for performing a safety function in the event of an SSE or OBE.31 License Basis Evaluation

-CGS TMU System The TMU system is and has always been a non-safety related system used to support the safety related UHS in the very unlikely probability that both ponds of the UHS (i.e., spray systems or water volume) are impacted by a tornado.This concept that a non-safety related system could support a safety related function is also presumed in 10 CFR 50.65(b)(2) (emphasis added): b) The scope of the monitoring program specified in paragraph (a)(1) of this section shall include safety related and nonsafety related structures, systems, and components, as follows: (2) Nonsafety related structures, systems, or components: (i) That are relied upon to mitigate accidents or transients or are used in plant emergency operating procedures (EOPs); or 4.2.4 WPPSS Response to NRC FSAR Review Question 10.40 (Amendment 21)In the WPPSS response to question 10.40, WPPSS calls the TMU system a safety-related piping system (see below).Q. 010.040 (3.5.1)The FSAR states that the water lines are "... tornado-hardened." State your criteria for protecting pipes located outside buildings from tornado missiles, including depth below grade requirements and provide drawings which show all pertinent tornado protection features as necessary.

Response:... The standby service water piping and the tower makeup water system from the river are the only safety-related water piping systems outside of tornado protected buildings.

Energy Northwest Response to Reference 4.2.4 Similarly to that described in response to reference 4.2.3, this statement is an imprecise use of the term "safety-related".

32 License Basis Evaluation

-CGS TMU System 4.2.5 WPPSS letter (GD Bouchey) to NRC (A Schwencer)

Submittal of Information Provided NRC Representatives During a Site Visit April 26-27, 1982, dated May 12, 1982 In attachment 3 of the above letter, WPPSS concluded that the safety function of the UHS was assured following a tornado because of the provisions of the TMU system. Reference the applicable text below: The Ultimate Heat Sink (UHS) spray piping networks are not considered tornado resistant and are assumed to be lost functionally following a tornado.The safety function of the UHS is assured by providing cooling water from the Columbia River via buried makeup water system piping. This system has three (3) pumps each capable of providing over 12,000 gpm to the spray ponds. The river water enters the pond near the standby service water intake, is pumped to the plant and back to the other pond where it overflows the pond weir and goes back to the river. The makeup pumps and pipe to the spray pond are protected from the effects of tornados, but the syphon is not protected since it is not required following a tornado.Energy Northwest Response to Reference 4.2.5 Refer to Energy Northwest response to references 4.2.3 and 4.2.4.4.2.6 FSAR Amendment 33 Sections 3.5.2, 3.8.4.1, 3.8.5.1.7, 9.2.5.3, 9.2.7, 9.4.12.3, and Appendix C (December 1983)Amendment 33 of the FSAR was the version in effect at the time of initial licensing of Columbia (formerly WNP-2). The connection with TMU being safety related was documented in the following sections:* Section 3.5.2, Systems To Be Protected.. The plant structures, systems, equipment, and components that are required to bring the plant to a safe shutdown condition, or whose failure could lead to offsite radiological consequences under accident conditions, are protected from external (outdoor) missiles by barrier structures or redundant systems as follows: b. The standby service water (SSW) and the tower makeup water (TMU)pipelines and electrical lines between the SSW pumphouses, the TMU pumphouse, the reactor building, and the diesel generator building are located below grade and are protected from external missiles by sufficient Quality Class 1 earth cover of high relative density (described in 3.5.3). The SSW and the TMU piping systems are the only safety-related water piping systems outside of tornado protected buildings.

The TMU system is required for safe shutdown only when both spray ring headers are lost to tornado missiles (see 3.3.2).33 License Basis Evaluation

-CGS TMU System* Section 3.8.4.1, Description of Structures (Other Non-Seismic Category I Safety Related Structures)

The following provides descriptive information of the various structures, other than the primary containment vessel and its internal structures, to define their primary structural aspects and elements relied on to perform their safety-related functions.

The relation between adjacent structures, including the separations provided, is also discussed.

Figures 1.2-1 through 1.2-24, 3.8-1, 3.8-2, 3.8-27 through 3.8-42, and 3.8-49 show arrangements and details of these structures.

The various plant structures discussed are the following:

f. Makeup water pump house and associated structures of the cooling tower makeup water system, such as valve box structures at points along the makeup water underground pipe line," Section 3.8.5.1.7, Non-Seismic Category I Safety Related Foundations The makeup water pumphouse is a non-Seismic Category I structure but is a safety related installation designed to withstand the Design Basis Tornado and tornado-generated missiles.* Appendix C, Conformance With NRC Regulatory Guides Regulatory Guide 1.27, Rev. 2, January 1976 Ultimate Heat Sink for Nuclear Power Plants Compliance or Alternate Approach Statement:

WNP-2 does not comply with the guidance set forth in Revision 2 of this regulatory guide.WNP-2 complies with the intent of the guidance set forth in Revision 1 of this regulatory guide by an alternate approach.General Compliance or Alternate Approach Assessment:

... Two Seismic Category I spray ponds are used, each with a capacity of 6.5 million gallons each. The makeup for these ponds is supplied from the pumphouse at the Columbia River. The makeup water piping is buried under a minimum of 5 feet of Quality Class I fill. The makeup water supply system is utilized only in the event of a design basis tornado, and therefore, it is not designed and constructed to withstand the effects of the OBE and water flow based on severe historical events in the region.34 License Basis Evaluation

-CGS TMU System The connection with TMU being safety related was documented in the following FSAR Amendment 33 sections: " Section 9.2.5.3, Safety Evaluation (Ultimate Heat Sink)... The possibility of a tornado passing over the spray pond and removing a significant amount of water is considered a credible event. For this reason, the makeup water pumphouse is designed to be tornado proof, with all piping and electrical power supply between the plant and the pumphouse underground.

Since it is not credible to assume an earthquake coincident with a tornado, this system need not be Seismic Category I. Two 12,500 gpm plant makeup water pumps are provided, one powered from each emergency diesel.generator.

Should pond water be lost due to a tornado, one of these pumps will be started to provide makeup. Makeup supply to the spray ponds is controlled by level switches that automatically open a supply valve to allow gravity drain from the circulating water pump basin to replenish spray pond level when it reaches the makeup setpoint." Section 9.2.7.2, System Description (Standby Service Water)The spray ponds are provided with makeup water by the circulating water system. The makeup water system supplies Columbia River water to the cooling towers or spray pond to replace water lost during normal operation due to evaporation and drift. In addition, the makeup system is designed to replace spray pond water lost during a tornado. To ensure system availability for this mode of operation, the makeup system is designed to withstand a design basis tornado coincident with a loss of offsite power.* Section 9.4.12.3, Safety Evaluation (HVAC Systems)The makeup water pumps are required to supply water to the SW spray ponds in the event a design basis tornado empties the ponds of their coolant (see Section 9.2.7).Energy Northwest Response to Reference 4.2.6 As noted in response to reference 4.2.1 and documented in GL 84-01, the use of phrase "safety related" was not always consistently applied. Energy Northwest acknowledges that the language in the referenced sections was not always consistently applied.In every case where the phrase was documented in terms of the characterization of structures, systems, or components (SSCs) associated with the TMU system or TMU pumphouse, it was used inconsistent with that established in FSAR Table 3.2-1 and section 3.2 of NUREG-0892 (e.g., FSAR sections 3.5.2 and 3.8.5.1.7).

It would be more consistent to state that although these SSCs are 35 License Basis Evaluation

-CGS TMU System non-safety related, they do provide an important to safety function associated with tornado events.In all other cases, where it was used to simply describe a "function" of the TMU system in the event of a tornado under the circumstances described in response to reference 5.2.3, Energy Northwest agrees that it was commonly mischaracterized as a "safety related" function.

This would also be true for any section that implies a safety related function but does not declare the function to be safety related in the text (e.g., FSAR Section 3.8.4.1, Appendix C, NUREG 0892 sections 9.2.5.3, 9.2.7.2, and 9.4.12.3).

4.2.7 NUREG-0892, WNP-2 Safety Evaluation Report Sections 3.5.2 and 9.4.6 In SER section 3.5.2, Structures, Systems, and Components to be Protected from Externally Generated Missiles, the NRC infers that the TMU system equipment in the TMU pumphouse is safety-related:

Except for the diesel generator exhausts, the fresh air intakes and exhausts for safety-related ventilation systems that service safety-related equipment are protected from tornado missiles by a concrete barrier or labyrinth, thereby protecting the safety-related equipment and areas from driving rains, snow, sleet, hail, and other natural phenomena.

The safety-related equipment is located in seismic Category I, tornado-missile-protected buildings, except for the makeup water pumphouse that is seismic Category II and is not required after an SSE. Therefore, the equipment inside this structure is protected from the effects of natural phenomena.

In SER section 9.4.6, the NRC concludes the following regarding the turbine building ventilation systems: The turbine building ventilation system provides the turbine building airflow requirements and is classified as nonsafety related (Quality Group D, nonseismic Category I) except for the makeup water transformer ventilation system. The ventilation system is capable of adequately maintaining an acceptable environment for personnel and the nonessential equipment served during normal plant operation.

Except for the makeup water transformer ventilation system, failure of the system does not compromise the operation of any essential systems and does not affect the capability to safely shut down the plant.Energy Northwest Response to Reference 4.2.7 Refer to the Energy Northwest response to reference 4.2.6.36 License Basis Evaluation

-CGS TMU System 4.3 Additional Supporting Information In addition to the references already provided in response to the NRC concerns in Section 4.2 of this position paper, Section 4.3.1 of this position paper provides other references regarding the non-safety classification of the TMU system.4.3.1 The TMU system was initially characterized as non-safety related as can be found in the following documents: " Figure 10.8-1 of the PSAR (submitted February 25, 1972) shows the Makeup Water from the river as Class UBC -Uniform Building Code.* Procurement Specification No. 225 purchased TMU valves as Quality Class II.* Procurement Specification No. 215 purchased TMU piping as Quality Class II (ANSI B31.1)." Construction Drawings for TMU (C536-C51 and C870) show all piping as Quality Class II 4.3.2 In response to a violation identified by the NRC in Inspection Report 84-007 in which a QC 1 system was not appropriately classified as QC 1 on work documents or the FSAR. WPPSS investigated the matter and noted in letter Lo2-84-007 a review of QC 1 components in QC 2 systems. This review identified the TMU as QC 2 system.5.0

SUMMARY

AND CONCLUSION Based on a thorough review of NRC requirements and early and current Licensing documentation it is Energy Northwest's position that the TMU system is a non-safety related support system for the Ultimate Heat Sink and does not require single failure protection to ensure the UHS remains operable.37 License Basis Evaluation

-CGS TMU System

6.0 REFERENCES

The following references were reviewed in the development of this position paper. Not all were referenced within the text of the report.6.1 Regulatory References

1. 10 CFR 50.2, Definitions

2. 10 CFR 100, Reactor Site Criteria 3. 10 CFR 50, Appendix A General Design Criteria for Nuclear Power Plants 4. 10 CFR 50, Appendix B, Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants 5. NRC Regulatory Guide 1.26, Quality Group Classifications and Standards for Water-, Steam-, and Radioactive-Waste-Containing Components of Nuclear Power Plants, Revision 3 (February 1976)6. NRC Regulatory Guide 1.27, Ultimate Heat Sink for Nuclear Power Plants, Revision 2 (January 1976)7. NRC Regulatory Guide 1.117, Tornado Design Classification, Revision 1 (April 1978)8. NUREG-0542 Evaluation of External Hazards to Nuclear Power Plants in the United States, December 1987 9. NUREG-0800, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants 10. NUREG-0892, Safety Evaluation Report Related to the Operation of WPPSS Nuclear Project No. 2, March 1982 11. NUREG-2123, Safety Evaluation Report Related to the License Renewal of Columbia Generating Station, May 2012 12. Federal Register, Volume 61, Number 239 (65157-65177)

13. Generic Letter 80-30, Clarification of the Term "Operable" As It Applies to Single Failure Criterion For Safety Systems Required by TS 14. Generic Letter 84-01 NRC use of the terms, "Important to Safety" and"Safety Related 38 License Basis Evaluation

-CGS TMU System 6.2 Correspondence (by date)1. Letter, Lo2-71-001, WPPSS (JJ Stein) to AEC (Dr. PA Morris), Application for Construction Permit and Facility License for Hanford No. 2 Nuclear Power Plant, dated August 10, 1971 2. Internal Memo, Burns & Roe (M. HroncichlWJ Ritsch to JJ Byrnes), W.O.2808, Washington Public Power Supply System, Hanford No. 2, Makeup Water System Safety Design Considerations, T.M. #200, dated April 25, 1972 3. Internal Memo, Burns & Roe (M. Hroncich to RT Richards), W.O. 2808-31, WPPSS, Hanford Project #2, River Water Pumps and Pump Structure, Technical Memorandum No. 525, dated June 7, 1973 4. Announcement, AEC, Forthcoming Meeting with Washington Public Power Supply System -Hanford No. 2, (Date unknown -prior to October 1973?)5. Letter, AEC (WR Butler) to WPPSS (JJ Stein), transmitting minutes of October 17-18, 1973 meeting, meeting agenda item No.6, dated November 20, 1973 6. Letter, AEC (VA Moore) to WPPSS (JJ Stein), no title (Construction Permit No. CPPR-93), dated March 19, 1973 7. Letter, GC2-74-28, WPPSS (JJ Stein) to AEC (A Giambusso), Ultimate Heat Sink, dated February 27, 1974 8. Letter, AEC (WR Butler) to WPPSS (JJ Stein), no title, dated July 26, 1974 9. Letter, BRWP-74-718, Burns & Roe (JJ Verderber) to WPPSS (JE Woolsey), W.O. 2808, Washington Public Power Supply System, Hanford No. 2, contract No. 225 Make Up water Pump House, dated August 14, 1974 10. Letter, Go2-74-30, WPPSS (JJ Stein) to AEC (A Giambusso), Ultimate Heat Sink Makeup Supply System Tornado Missile Protection, dated September 16,1974 11. Internal Memo, Burns & Roe (J Foreman to JJ Verderber), W.O. 2808 Washington Public Power Supply System, WPPSS Nuclear Project No. 2, Quality Assurance Classification of Piping and Fitting, to be Prepurchased, for the 225 Contractor by WPPSS, Technical Memorandum No. 705, dated October 8, 1974 12. Internal Memo, Burns & Roe (J Foreman to JJ Verderber), W.O. 2808, WPPSS, Nuclear Project No. 2, Ultimate Heat Sink Design, Technical Memorandum No. 770, dated February 14, 1975 39 License Basis Evaluation

-CGS TMU System 13. Internal Memo, Burns & Roe (J Foreman to JJ Verderber), W.O. 2808, WPPSS Nuclear Project No. 2, Plant Service Water Pumps and Other Non-Class 1 E 4160 Volt Switchgear Connections to Emergency Buses, Technical Memorandum No. 895, Rev. 1, dated May 26,1976 14. Letter, Go2-82-036, WPPSS (GD Bouchey) to NRC (A Schwencer), Nuclear Project No. 2 Submittal of Information Provided NRC Representatives During A Site Visit April 26-27, 1982, dated May 12, 1982 15. Letter Go2-82-523, WPPSS (RG Matlock) to NRC (RH Engelken), Supply System Nuclear Project No. 2 Tenth Progress Report -1OCFR50.54(f), dated June 10, 1982 16. Letter, NRC (DG Eisenhut) to WPPSS (DW Mazur), Issuance of Facility Operating License NPF-21 -WPPSS, Nuclear Project No. 2, dated December 20, 1983 17. NRC Inspection Report 84-07, dated April 18, 1984 18. Letter, WPPSS (J. D. Martin) to NRC (RA Scarano), Nuclear Plant No. 2, License No. NPF-21, NRC Inspection 84-07 March 19-23, 1984, dated June 15, 1984 19. Letter, Go2-86-243, WPPSS (GC Sorensen) to NRC (EG Adensam), Nuclear Plant No. 2 Operating License NPF-21, Request for Amendment to License -(Ultimate Heat Sink), dated March 21, 1986 20. Letter, NRC (RB Samworth) to WPPSS (GC Sorensen), Issuance Of Amendment No. 52 to Facility Operating License NPF-21 -WPPSS Nuclear Project No. 2 (Tac No 61014), dated April 4, 1988 21. NRC Inspection Report 93-201, Service Water System Operational Performance Inspection, dated April 1, 1993 22. NRC Memorandum, Response to Task Interface Agreement (TIA) Regarding Northern States Power Company (Monticello)

Definition of Non-Safety Related (AIT 97-018), dated February 2, 1999 23. NRC Memorandum, DC Cook -Task Interface Agreement (TIA)99-031 -Evaluation of the Acceptability of the Classification and Field Installation of Non-Safety-Related Control Cables Used in the Load Shedding Circuitry to Perform the Safety-Related Function of Shedding Loads off Safety-Related Buses, dated February 29, 2000 24. NRC Letter to Perry Nuclear Station, Application of Generic Letter 80-30 Guidance to an Inoperable Non-Technical Specification Support Subsystem, dated April 5, 2002 40 License Basis Evaluation

-CGS TMU System 25. NRC Inspection Report 2003-06, Columbia Generating Station -NRC Integrated Inspection Report dated November 5, 2003 26. NRC Memorandum, Final Response to Task Interface Agreement 2012-03, Regarding Plant Design and Licensing Basis on Diesel Fuel Oil Supply of the Emergency Diesel Generators at Monticello Nuclear Generating Plant, dated August 20, 2013 6.3 Columbia Specific Documents 1. Preliminary Safety Analysis, August 10, 1971 2. Final Safety Analysis Report, Amendment 33 (Initial Licensed version)3. Final Safety Analysis Report, Amendment 63 (current)4. Technical Specifications, Amendment 57 5. Technical Specifications, Amendment 230 (current)6. Operational Quality Assurance Description Program (OQAPD), Revision 47 (current)7. Design Basis Document 309, Standby Service Water System, Revision 8 41