ML021100001
| ML021100001 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 04/19/2002 |
| From: | Wang A NRC/NRR/DLPM/LPD4 |
| To: | Ridenoure R Omaha Public Power District |
| References | |
| TAC MB4664 | |
| Download: ML021100001 (19) | |
Text
April 19, 2002 Mr. R. T. Ridenoure Division Manager - Nuclear Operations Omaha Public Power District Fort Calhoun Station FC-2-4 Adm.
Post Office Box 550 Fort Calhoun, NE 68023-0550
SUBJECT:
FORT CALHOUN STATION, UNIT NO. 1 - ISSUANCE OF AMENDMENT (TAC NO. MB4664)
Dear Mr. Ridenoure:
The Commission has issued the enclosed Amendment No. 206 to Facility Operating License No. DPR-40 for the Fort Calhoun Station, Unit No. 1. The amendment consists of changes to the Technical Specifications (TS) in response to your application dated April 1, 2002, as supplemented by letters dated April 10 and April 15, 2002. Pursuant to 10 CFR 50.91(a)(6), the licensee requested the proposed amendment on an exigent basis.
The amendment adds an exception to the technical specifications to perform the surveillance test of Table 3-2, Item 20 (Recirculation Actuation Logic Channel Functional Test) under administrative controls while components in excess of those allowed by Conditions a, b, d, and e of TS 2.3(2) are maintained operable by dedicated operator action and are required to be returned to operable status within one hour. This exception will apply only to the remainder of Cycle 20 and the entirety of Cycle 21. In addition, the licensee has committed to submit a permanent resolution no later than January 31, 2003. The staff processed this amendment on an exigent basis.
A copy of the related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commissions next biweekly Federal Register notice.
Sincerely,
/RA/
Alan B. Wang, Project Manager, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-285
Enclosures:
- 1. Amendment No. 206 to DPR-40
- 2. Safety Evaluation cc w/encls: See next page
April 19, 2002 Mr. R. T. Ridenoure Division Manager - Nuclear Operations Omaha Public Power District Fort Calhoun Station FC-2-4 Adm.
Post Office Box 550 Fort Calhoun, NE 68023-0550
SUBJECT:
FORT CALHOUN STATION, UNIT NO. 1 - ISSUANCE OF AMENDMENT (TAC NO. MB4664)
Dear Mr. Ridenoure:
The Commission has issued the enclosed Amendment No. 206 to Facility Operating License No. DPR-40 for the Fort Calhoun Station, Unit No. 1. The amendment consists of changes to the Technical Specifications (TS) in response to your application dated April 1, 2002, as supplemented by letters dated April 10 and April 15, 2002. Pursuant to 10 CFR 50.91(a)(6), the licensee requested the proposed amendment on an exigent basis.
The amendment adds an exception to the technical specifications to perform the surveillance test of Table 3-2, Item 20 (Recirculation Actuation Logic Channel Functional Test) under administrative controls while components in excess of those allowed by Conditions a, b, d, and e of TS 2.3(2) are maintained operable by dedicated operator action and are required to be returned to operable status within one hour. This exception will apply only to the remainder of Cycle 20 and the entirety of Cycle 21. In addition, the licensee has committed to submit a permanent resolution no later than January 31, 2003. The staff processed this amendment on an exigent basis.
A copy of the related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commissions next biweekly Federal Register notice.
Sincerely,
/RA/
Alan B. Wang, Project Manager, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-285 DISTRIBUTION:
PUBLIC GHill (2)
Enclosures:
- 1. Amendment No. 206 to DPR-40 PDIV-2 Reading LHurley, RIV
- 2. Safety Evaluation RidsNrrDlpmPdiv (SRichards)DBujol, RIV RidsNrrPMAWang DTrimble cc w/encls: See next page RidsNrrLAEPeyton MJohnson RidsOgcRp
- For previous concurrences see RidsACRSACNWMailCenter attached ORC CMarschall, RIV WBeckner ACCESSION NO.: ML021100001 OFFICE PDIV-2/PM PDIV-2/LA IOLB/SC*
SPSB*
OGC*
PDIV-2/SC NAME AWang EPeyton DTrimble MJohnson/
M. Rubin for SBrock SDembek DATE 04/15/02 04/15/02 4/17/02 4/17/02 4/17/02 04/18/02 OFFICIAL RECORD COPY
Ft. Calhoun Station, Unit 1 cc:
Winston & Strawn ATTN: James R. Curtiss, Esq.
1400 L Street, N.W.
Washington, DC 20005-3502 Mr. Jack Jensen, Chairman Washington County Board of Supervisors Blair, NE 68008 Mr. Wayne Walker, Resident Inspector U.S. Nuclear Regulatory Commission Post Office Box 309 Fort Calhoun, NE 68023 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011 Ms. Julia Schmitt, Section Administrator Nebraska Health and Human Services Systems Division of Public Health Assurance Consumer Services Section 301 Cententiall Mall, South P. O. Box 95007 Lincoln, Nebraska 68509-5007 Mr. David J. Bannister Manager - Fort Calhoun Station Omaha Public Power District Fort Calhoun Station FC-1-1 Plant Post Office Box 550 Fort Calhoun, NE 68023-0550 Mr. Mark T. Frans Manager - Nuclear Licensing Omaha Public Power District Fort Calhoun Station FC-2-4 Adm.
Post Office Box 550 Fort Calhoun, NE 68023-0550 Mr. Daniel K. McGhee Bureau of Radiological Health Iowa Department of Public Health 401 SW 7th Street Suite D Des Moines, IA 50309
OMAHA PUBLIC POWER DISTRICT DOCKET NO. 50-285 FORT CALHOUN STATION, UNIT NO. 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 206 License No. DPR-40 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by the Omaha Public Power District (the licensee) dated April 1, 2002, as supplemented by letters dated April 10 and April 15, 2002, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.
The issuance of this license amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.
2.
Accordingly, Facility Operating License No. DPR-40 is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 3.B. of Facility Operating License No. DPR-40 is hereby amended to read as follows:
B.
Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 206, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.
3.
The license amendment is effective as of its date of issuance and shall be implemented with 30 days of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION
/RA/
Stephen Dembek, Chief, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications Date of Issuance: April 19, 2002
ATTACHMENT TO LICENSE AMENDMENT NO. 206 FACILITY OPERATING LICENSE NO. DPR-40 DOCKET NO. 50-285 Replace the following pages of Appendix A Technical Specifications with the attached revised pages. The revised pages are identified by amendment number and contain vertical lines indicating the areas of change.
REMOVE INSERT 2-21 2-21 2-23b 2-23b
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 206 TO FACILITY OPERATING LICENSE NO. DPR-40 OMAHA PUBLIC POWER DISTRICT FORT CALHOUN STATION, UNIT NO. 1 DOCKET NO. 50-285
1.0 INTRODUCTION
By application dated April 1, 2002, as supplemented by letters dated April 10 and April 15, 2002, Omaha Public Power District (OPPD) requested changes to the Technical Specifications (Appendix A to Facility Operating License No. DPR-40) for the Fort Calhoun Station, Unit No. 1 (FCS). Pursuant to 10 CFR 50.91(a)(6), the licensee requested the proposed amendment on an exigent basis. The requested changes would add an exception to the technical specifications (TS) to perform the surveillance test of Table 3-2, Item 20 (Recirculation Actuation Logic Channel Functional [RALCF] Test) under administrative controls while components in excess of those allowed by Conditions a, b, d, and e of TS 2.3(2) are maintained operable by dedicated operator action and are required to be returned to operable status within one hour. This exception will apply only to the remainder of Cycle 20 and the entirety of Cycle
- 21. The supplemental letters dated April 10 and April 15, 2002, provided additional information that clarified the application, did not expand the scope of the application as originally noticed or revise the proposed TS changes, but did modify the staffs original proposed no significant hazards consideration determination as published in the Federal Register on April 4, 2002 (67 FR 16130). The staffs final no significant hazards consideration determination is provided below.
2.0 BACKGROUND
FCS was licensed for full power operation in 1973 by the NRC. The emergency core cooling system (ECCS) was designed with three high pressure safety injection (HPSI) pumps and two low pressure safety injection (LPSI) pumps that have a common recirculation minimum flow header to the safety injection refueling water tank (SIRWT). During a loss-of-coolant accident (LOCA), or other accidents which generate a safety injection actuation signal (SIAS), the HPSI and LPSI pumps start and pressurize their injection headers. If the reactor coolant system (RCS) pressure is higher than the shutoff head of these pumps, a single recirculation minimum flow line provides sufficient flow to allow all five pumps to operate without damage to the pumps.
After an accident that allows injection into the RCS, the recirculation actuation signal (RAS) automatically switches the HPSI and containment spray (CS) pump suction to the containment sump when the water level in the SIRWT falls to a preset level. At this time, the flow path from the containment sump is opened, the SIRWT flow path is closed, the LPSI pumps are stopped automatically, and water is recirculated from the containment sump by the HPSI and CS pumps.
The recirculation minimum flow line to the SIRWT is isolated by two valves in series to prevent depositing potentially contaminated water into a tank outside of the reactor containment building. These valves are normally open and fail open on loss of air or loss of 125 VDC power.
These valves perform a passive safety function in the OPEN position. The valves are designed to provide a recirculation minimum flow path from the SI and CS pumps to the SIRWT to prevent deadheading the pumps during SI and CS. These valves also perform an active safety function in the closed position to isolate the SIRWT on a RAS signal. This effectively prevents depositing potentially radioactive water into a tank outside the containment building. At this stage of the accident, isolation of the recirculation minimum flow path is not a concern with respect to pump operability since reactor coolant pressure would be well below the pumps discharge head and a minimum flow rate would be achieved.
During the RALCF test, a RAS signal is generated and one of the recirculation minimum flow valves closes. Until a recent NRC inspection, FCS had previously credited the use of dedicated operators to allow the tested equipment to remain operable. OPPD assumed that an operator could be used during the test to ensure that in the event of an engineered safeguards features (ESF) actuation, the test could be rapidly terminated and the recirculation minimum flow valve opened to allow a minimum flow path for the HPSI and LPSI pumps. The actions required to be performed to allow the recirculation minimum flow valve to open can be rapidly performed by one dedicated operator in less than one minute. During the NRC Safety System Design and Performance Capability (SSDPC) inspection in February 2002, FCS personnel were informed that manual actions could not be used in lieu of automatic actions to maintain equipment operable without prior NRC approval. A comprehensive review was conducted of plant procedures that used manual actions in place of automatic actions in order to allow equipment to remain operable. The quarterly RALCF test is the only test identified to date in this review requiring credit for operator action during the test. In attempting to upgrade this procedure to eliminate this practice, OPPD determined that this procedure could not be performed without seeking NRC approval for some change to the testing methodology. OPPD had considered a number of possible solutions, but in the short term OPPD has determined a TS change is necessary, to allow careful consideration of the appropriate approach to any permanent changes to the TSs or the plant.
The proposed license amendment is needed to maintain compliance with TS 2.3(2) during surveillance testing. TS 2.3(2) only permits one of its listed conditions to be true at any one time. A test of one of the two channels was due to be performed on March 21, 2002, and will exceed its surveillance interval and extension on April 21, 2002. Current performance of the surveillance test of Table 3-2, Item 20 requires entry into TS 2.0.1(1) since components in excess of those allowed by Conditions a, b, d, and e of TS 2.3(2) would be inoperable. With the proposed testing methodology, if the RALCF test cannot be performed, per TS 2.15, FCS would ultimately be shutdown in 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br />.
The proposed amendment adds an exception to perform the surveillance test of Table 3-2, Item 20 (Recirculation Actuation Logic Channel Functional Test) under administrative controls while components in excess of those allowed by Conditions a, b, d, and e of TS 2.3(2) are maintained operable by dedicated operator action and are required to be returned to operable status within one hour. OPPD requests that this exception to be in place for the remainder of Cycle 20 and all of Cycle 21.
OPPD has stated that a modification to the plant may not be the most desirable solution. A permanent change to the TS may be the best solution. OPPD is investigating a permanent change but that will require additional technical work. OPPD expects that this review and comment period would take several months. OPPD plans to advise the NRC of the permanent resolution and/or submit an appropriate license amendment request no later than January 31, 2003.
3.0 EVALUATION The April 1, 2002, submittal proposed to credit operator action to restore ECCS function should a LOCA occur during the RALCF test. After several discussions with the staff, OPPD revised this request by letter dated April 10, 2002. This revision would allow the continued testing of the logic channels using an improved methodology (i.e., one that does not isolate the recirculation minimum flow path) for a limited time. The licensee has proposed to have one dedicated operator to hold the recirculation flow line and one dedicated operator to hold the sump valves in position during the RALCF test. This will assure that the safety injection (SI) pumps will not be deadheaded at any time. Should a RAS occur during any accident, the signal from the train not being tested will initiate closure of the other recirculation valve and thus perform the necessary safety function. Failure to perform the actions or to reset the RAS would only result in the unnecessary continued opening of the recirculation and pump suction valves.
The one-hour completion time is considered sufficient time to perform the quarterly RALCF test.
Additionally, the one-hour completion time ensures that prompt action is taken to restore the required ECCS capacity. The one-hour completion time allowed to satisfy ECCS requirements is acceptable based on the small probability of an event occurring during this time interval that the test is performed and the desire to minimize plant shutdown transients.
The proposed TS changes are as follows:
(1)
Add the following item "i" to TS 2.3(2), page 2-21:
"Components in excess of those allowed by Conditions a, b, d, and e may be inoperable provided they are returned to operable status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> when performing the quarterly recirculation actuation logic channel functional test (Table 3-2 item 20) under administrative controls. This allowance applies only to the remaining portion of Cycle 20 and all of Cycle 21."
(2)
Revise the Bases text describing the actions to be taken due to the need for dedicated operator action to maintain the system components operable during the test.
The April 10 and April 15, 2002, letters provided changes to the proposed administrative controls only. OPPD did not request revisions to the April 1, 2002, proposed TS changes. The new administrative controls did not change the intent of the April 1, 2002, request to credit operator action but redefined the operator actions to maintain ECCS availability throughout the test and simplified the required actions.
3.1 Human Factors Assessment To perform its review for crediting operator actions, the staff used the following as guidance and acceptance criteria for this review:
(1)
U.S. NRC Information Notice 97-78, "Crediting of Operator Actions in Place of Automatic Actions and Modification of Operator Actions, Including Response Times."
(2)
NUREG/CR-6689, "Proposed Approach for Reviewing Changes to Risk-important Human Actions," October, 2000.
(3)
ANSI/ANS-58.8 (1984, 1994), "Time Response Design Criteria for Safety-related Operator Actions."
As previously stated, the change is being proposed to allow the performance of the RALCF test without violating TSs or necessitating a unit shutdown because the test cannot be performed.
The proposed administrative controls "consist of stationing three dedicated operators at the ESF panel controls in the control room." In this way, the following conditions are maintained and actions can be rapidly performed should a valid ESF actuation occur:
the appropriate SIRWT to SI and CS pumps suction valve control switch is maintained in the OPEN position (spring-return switch),
the appropriate SI and CS pumps to SIRWT recirculation minimum flow valve control switch is maintained in the OPEN position (spring-return switch),
the appropriate RAS lockout relays and initiating signal can be rapidly reset, the appropriate SI and CS pumps to SIRWT recirculation minimum flow valve control switch can be rapidly returned to the AUTO position, the appropriate SIRWT to SI and CS pumps suction valve control switch can be rapidly returned to the AUTO position, and the appropriate containment sump to SI and CS pumps suction valve control switch can be rapidly returned to the AUTO position.
The licensee further states that appropriate SI and CS pumps to SIRWT recirculation minimum flow valve control switch and the appropriate SIRWT to SI and CS pumps suction valve control switch are held in the OPEN position during the test to enhance the reliability of the SI and CS pumps by maintaining the associated valves open to prevent deadheading the pumps or isolating the pumps from the SIRWT, respectively.
The test procedure proposed by the licensee requires using two dedicated operators who are briefed on the actions required to maintain recirculation minimum flow and SIRWT suction alignment to the SI and CS pumps during the RAS testing. A third dedicated operator (the operator who is assigned the responsibility for performing the RAS test) is also assigned and briefed on the actions to implement the appropriate restorative actions if a valid ESF actuation occurs. The appropriate steps within the RALCF test procedure provide directions for this operator to reset three lockout relays to return the tested train to its normal condition. The licensee indicates that if a recirculation minimum flow valve or SIRWT to SI and CS pumps suction valve control switch is inadvertently released, the switch can be rapidly returned to the OPEN position, thus reopening the affected valve and returning it to the open position.
In response to the staffs request for additional information, on April 15, 2002, the licensee provided a detailed description of the significant procedural steps of the RAS Test which is part of the draft revision to their Surveillance Test Procedure OP-ST-ESF-0010. In addition, the licensee submitted a color photograph, correlated to the procedural steps, that identified the six control devices important to performing the RAS test. In the description, the licensee indicates that the RAS test takes "normally 4 to 6 minutes and not more than 15 minutes to perform."
The operator performing the RAS test is the dedicated operator who returns the affected equipment to its automatic alignment if an ESF actuation occurs during the test. A second dedicated operator is stationed at the ESF control panel to hold the spring-return control switch to maintain the pump suction valve open and the third dedicated operator is stationed at the same panel to hold the spring-return control switch to maintain the recirculation valve open.
The licensee notes that the test is written to allow for a fourth operator to return the affected equipment to its automatic alignment if an ESF actuation occurs during the test but, "it is customary to have the operator performing the test serve this function." The licensee states that using four operators does not cause overcrowding at the ESF control panel because the fourth operator could "observe the relays from several feet away then step forward, in the event of an ESF actuation," to perform the required equipment alignments.
In its April 15, 2002, submittal, the licensee included a description of simulator sessions that were used to demonstrate performance of "the changes being made to the existing and long standing surveillance test OP-ST-ESF-0010 to incorporate dedicated operators as a means of maintaining system capability." Two simulator sessions were conducted. During the first session, using one dedicated operator to perform the test and a second dedicated operator to manipulate valve controls, three test simulations were performed: (1) OP-ST-ESF-0010 was conducted during normal power operations, (2) OP-ST-ESF-0010 was conducted with large break loss-of-coolant accident, and (3) repeat of (2). The first simulation test demonstrated that the testing would require the operators to hold the SI tank pump inlet valves open for 4 minutes to complete signal testing under normal conditions. The second two exercises demonstrated that pump inlet and mini recirculation valves could be returned to automatic control functions, using the required Attachment 4 of OP-ST-ESF-0010, within one minute after actuation of the pressurizer pressure low signal (PPLS). Other minor procedural enhancements, such as streamlining the restoration of components following testing, were also incorporated.
The second simulation session was conducted using one dedicated operator to perform the test and two additional dedicated operators each to hold open the mini-flow recirculation valve or safety injection tank pump inlet header valve respectively. No accident was simulated because the purpose of this session was to test operator positioning and operability of the controls with three operators at the ESF control panel. This session demonstrated: (1) operator placement, although in closer than normal separation, did not interfere with or impede the operators ability to perform assigned functions; (2) the effectiveness of procedural enhancements to minimize operator interactions and panel view obstructions; (3) the capability of each of the two dedicated valve switch operators to indefinitely maintain the switches in the OPEN position; (4) the ability of the operators to change hands on a switch handle to avoid hand fatigue and; (5) the control systems capability to immediately return valves to the OPEN position in the event of an inadvertent release of the valve control switch handle.
As part of its analysis, the licensee states in its April 10, 2002, submittal that, "if either operator fails to maintain his valve open, the single action of returning the switch to the OPEN position is sufficient to immediately recover and restore the valve to the open position. These two operators perform no active restoration functions..."
In comparing the proposed actions with their USAR Chapter 14 safety analysis in its April 10, 2002 submittal, the licensee indicates that performance of the RALCF test uses a dedicated operator to hold open the SIRWT to SI and CS pumps suction valve control switch until the RAS relays have been reset. If it is postulated the operator fails to hold the valve open, then one train of HPSI, LPSI, and CS is rendered inoperable. Loss of one train of HPSI, LPSI, and CS is equivalent to loss of off-site power and the failure of one diesel to start. This scenario has been previously evaluated and meets the ECCS design basis. One train of HPSI, LPSI, and CS will remain available and satisfy their design function. USAR Chapter 14 safety analyses, in the most limiting cases, only assumes one train of HPSI, LPSI, and CS. A second dedicated operators responsibility is to maintain recirculation minimum flow to the SIRWT. A third dedicated operator is also assigned and briefed on the actions to implement the appropriate restorative actions if a valid ESF actuation occurs.
The staff believes that OPPD has demonstrated that the proposed operator actions are reliable and can be performed in a safe and timely manner. The actions will assure that ECCS function is not lost during the RALCF/RAS test. In addition, the consequences of not performing the actions to reset the RAS should an ESF signal occur, would only result in the unnecessary continued opening of the recirculation and pump suction valves. Based on the results of the licensees analysis as evaluated using the guidance and acceptance criteria identified at the beginning of this section, the staff concludes that crediting operator action, as proposed in the license amendment request is acceptable because there is reasonable assurance that the proposed credit for operator action will maintain the ECCS in operable condition during the RALCF test.
3.2 Probabilistic Safety Assessment (PSA) Insights The April 1, 2002, submittal proposed to credit operator action to restore ECCS function should a LOCA occur during the RALCF test. After several discussions with the staff, OPPD revised this request by letter dated April 10, 2002. This revision would allow the continued testing of the logic channels using an improved methodology (i.e., one that does not isolate the recirculation minimum flow path) for a limited time. The licensee has proposed to have one dedicated operator to hold the recirculation flow line and one dedicated operator to hold the sump valves in position during the RALCF test. This will assure that the SI pumps will not be deadheaded at any time. Should a RAS occur during any accident, the signal from the train not being tested will initiate closure of the other recirculation valve and thus perform the necessary safety function. Failure to perform the actions or to reset the RAS would only result in the unnecessary continued opening of the recirculation and pump suction valves. Therefore, OPPD states that since the operators perform no active restoration functions, the revised approach is highly reliable and the risk is less than that previously evaluated in the April 1, 2002, submittal. The staff has provided the following analysis as a bounding estimate for operator error inclusion.
3.2.1 Tier 1 For the TS change to allow surveillance testing for the RAS to be performed with a dedicated operator, the licensee computed the annualized delta core damage frequency (CDF) for FCS to be 1.6 E-07/yr, which is very small compared to the guidelines of Regulatory Guide (RG) 1.174, "An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis." The annualized delta large early release frequency, which is a fraction of the annualized delta core damage frequency, would also be very small according to the guidelines of RG 1.174 (less than 1.0 E-07/yr).
The licensee computed the incremental conditional core damage probability (ICCDP) to be 1.2 E-08, which is significantly smaller than the RG 1.177, "An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications," guideline of 5.0 E-07, indicating a very small quantitative risk impact. The incremental large early release probability (ICLERP) is a fraction of the ICCDP, and is therefore small compared with or comparable to the RG 1.177 guideline of 5.0 E-08.
The above licensee-computed values of delta CDF, ICCDP, and inferences of the acceptably small values of delta LERF and ICLERP are reasonable and acceptable to the staff. There is also an unquantified risk reduction due to non-testing at shutdown.
3.2.2 Tier 2 There are no specific Tier 2 requirements for this surveillance testing activity.
3.2.3 Tier 3 In accordance with 10 CFR 50.65(a)(4), the licensee performed a risk evaluation for performing the RALCF test with the dedicated operators manual actions in lieu of automatic actions.
A failure probability of 0.01 was assigned by the licensee for the dedicated operators to perform the steps necessary to open the appropriate recirculation minimum flow valve upon the initiating prompt signal of a LPSI or HPSI pump starting. The licensee judged the actions of resetting the relays and opening the valve to be simple tasks with all indications and controls grouped together in the same area in which the test is performed.
The licensee allowed no credit for the dedicated operators holding the safety injection suction isolation valve open (i.e., one train of CS, HPSI, and LPSI are assumed to be available).
3.2.4 PSA Quality FCS was the pilot plant for the Combustion Engineering Owners Group (CEOG) peer review process. The peer review, performed in 1999, found the FCS PSA to be effective for assessing planned maintenance and operations configurations and evaluating future plant design changes. The PSA was also found to be adequate for other applications where supported by deterministic insights and plant expert panel input. The review did identify areas for improvement to be explicitly considered in any future application. The majority of the improvements have been made, including all high importance issues. Work is still in progress in the following generally important areas:
Human reliability analysis: The CEOG peer review recommended better supporting documentation for HRA, as well as re-analysis of selected human failure events (HFEs).
Improvement of documentation consistent with current industry standards has been started. HFEs with high risk importance have been re-analyzed. The licensee believes that the HRA is of sufficiently high quality to support the application of the PSA.
Documentation: Upgrades were recommended for a number of the licensees PSA areas. While some of these documentation upgrades have yet to be completed, the licensee expects that the impact on the PSA model itself will be minimal.
The licensee has considered the areas of improvement identified by the peer review and has concluded that changes in these areas would not affect the PSA results.
3.2.5 External Events ESF testing is only significant for accident sequences that start the high pressure SI pumps, but result in RCS pressures greater than the pump shutoff head. These sequences include small-break LOCAs, steam generator tube ruptures, and reactor coolant pump (RCP) seal LOCAs.
The majority of accident sequences initiated by external events or internal floods do not require SI. Those that do are either medium LOCAs (e.g., once-through-cooling or stuck-open power-operated relief valve [PORV]) that rapidly lower RCS pressure below the HPSI pump shutoff head, or RCP seal LOCAs that develop over a course of hours. An accident sequence that develops slowly allows ample time to terminate the ESF testing and realign the ESF system.
The staff concludes that the impact on plant risk of allowing the FCS to perform the surveillance test for the RAS with the dedicated operators is very small for both internal and external events.
The staff has also concluded that crediting operator action for the remaining of Cycle 20 and Cycle 21, will provide assurance that ECCS function is not lost during the RALCF test.
Therefore, the staff has found the proposed TS change to be acceptable.
3.3 Change to the Bases Section Bases Section 2.3, "Emergency Core Cooling System," has been revised to reflect the proposed TS changes. The staff has reviewed these Bases changes and has no objections to them.
4.0 EXIGENT CIRCUMSTANCES
The Commissions regulations, 10 CFR 50.91, contain provisions for issuance of amendments when the usual 30-day public notice period cannot be met. One type of special exception is an exigency. An exigency is a case where the staff and licensee need to act promptly. The exigency case usually represents an amendment involving a safety enhancement to the plant.
Pursuant to 10 CFR 50.91(a)(6), the licensee requested the proposed amendment on an exigent basis.
Under such circumstances, the Commission notifies the public in one of two ways: by issuing a Federal Register notice providing an opportunity for hearing and allowing at least two weeks for prior public comments, or by issuing a press release discussing the proposed changes, using local media. In this case, the Commission used the first approach.
During the NRC SSDPC inspection in February 2002, FCS personnel were informed that manual operator actions could not be used in lieu of automatic actions to maintain equipment operable without prior NRC approval. The licensee conducted a comprehensive review of plant procedures that used manual actions in place of automatic actions in order to allow equipment to remain operable. The quarterly RALCF test was identified as one of the tests affected. The licensee determined on March 26, 2002, that the RALCF surveillance test was the only surveillance that could not be performed without taking credit for manual operator action. The licensee stated that there is insufficient time to make a modification to allow the performance of the RALCF surveillance test before the test interval expires. This test was due to be performed on March 21, 2002, and will exceed its surveillance frequency and extension on April 21, 2002.
The plant would be required to shut down within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> if this test is not performed by April 21, 2002. Therefore, OPPD has requested an exigent TS change to allow this surveillance to be performed to avoid shutting down the plant.
There were no public comments in response to the notice published in the Federal Register.
5.0 FINAL NO SIGNIFICANT HAZARDS CONSIDERATION
DETERMINATION The Commissions regulations in 10 CFR 50.92 state that the Commission may make a final determination that a license amendment involves no significant hazards considerations if operation of the facility in accordance with the amendment would not: (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in margin of safety.
Operation of the facility in accordance with the proposed amendment will not involve a significant increase in the probability or consequences of an accident evaluated. Performance of the quarterly surveillance test of Table 3-2, Item 20 (Recirculation Actuation Logic Channel Functional Test) under administrative controls while components in excess of those allowed by Conditions a, b, d, and e of TS 2.3(2) are maintained operable by dedicated operator action and are required to be returned to operable status within one hour, will not affect the probability of any accident since the performance of the RALCF test is not identified as the initiator of any analyzed event. This exception applies only to the remaining portion of Cycle 20 and all of Cycle 21. The proposed change will still require that the surveillance test be performed and the required ECCS systems to be available. The one-hour completion time is considered sufficient time to perform the quarterly RALCF test. Additionally, the one-hour completion time ensures that prompt action is taken to restore the required ECCS capacity. The administrative controls in place will ensure that all required ECCS components remain available with compensatory dedicated operators. This change will not alter assumptions relative to the mitigation of an accident or transient event. The performance of this activity has no effect on any accident scenario. Therefore, the proposed change does not involve a significant increase in the consequences of an accident previously evaluated.
Operation of the facility in accordance with the proposed amendment will not create the possibility of a new or different kind of accident from any accident previously evaluated. The proposed changes do not involve a physical alteration of the plant (no new or different type of equipment will be installed) or change the methods governing plant operation. The proposed change does not involve any physical changes to plant systems, structures or components (SSCs) or the manner in which these SSCs are operated, maintained, modified or inspected.
Therefore, these changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.
Operation of the facility in accordance with the amendment will not involve a significant reduction in the margin of safety. The operator actions to hold the appropriate SIRWT to SI and CS pumps suction valve control switch and the appropriate SI and CS pumps to SIRWT recirculation minimum flow valve control switch in the OPEN position, thus maintaining the recirculation minimum flow path open, are judged to be highly reliable. Additionally, if the either operator fails to maintain his valve open, the single action of returning the switch to the OPEN position is sufficient to immediately recover and restore the valve to the open position.
Therefore, the conclusion of the qualitative risk assessment is that the performance of the RALCF test is a low risk evolution. The proposed change does not affect the frequency of the RALCF test. The administrative controls in place will ensure that all required ECCS components remain available. The minimum number of ECCS components required by the FCS accident analyses remain available with compensatory dedicated operators. The proposed change will not significantly impact the availability or reliability of the plants systems or their ability to respond to plant transients and accidents. The one-hour completion time allowed to satisfy ECCS requirements is acceptable based on the small probability of an event occurring during this time interval that the test is performed and the desire to minimize plant shutdown transients. The performance of this activity has no affect on any accident scenario.
Therefore, the proposed changes do not involve a significant reduction in a margin of safety.
Based upon the above considerations, the staff concludes that the amendment meets the three criteria of 10 CFR 50.92. Therefore, the staff has made a final determination that the proposed amendment does not involve a significant hazards consideration.
6.0 STATE CONSULTATION
In accordance with the Commissions regulations, the Nebraska State official was notified of the proposed issuance of the amendment. The State official had no comments.
7.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has made a final finding that the amendment involves no significant hazards consideration. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
8.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: M. Wohl J. Bongarra A. Wang Date: April 19, 2002