ML20072C761
| ML20072C761 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 08/12/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20072C757 | List: |
| References | |
| NUDOCS 9408180085 | |
| Download: ML20072C761 (7) | |
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E UNITED STATES l'
NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 2055M001
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 161 TO FACILITY OPERATING LICENSE NO. DPR-20 CONSUMERS POWER COMPANY PALISADES PLANT DOCKET NO. 50-255
1.0 INTRODUCTION
By letter dated June 28, 1989, as supplemented by letters dated May I and September 26, 1991, March 18, August 24, and August 28, 1992, May 19, 1993, May 5 and July 7,1994, Consumers Power Company (the licensee) requested an amendment to the Technical Specifications (TS) appended to Facility Operating License No. DPR-20 for the Palisades Plant.
The proposed amendment would add new operational requirements, action statements, and surveillance requirements to assure the availability of shutdown cooling (SDC) to the primary coolant system (PCS) during certain operational conditions.
Specifically, the proposed amendment would add new TS Section 3.1.9 and 3.7.3, and would add Item 14 to Table 4.2.2.
Also, as a result of a recent review of the SDC system piping stress analysis, additional TS changes are made restricting operability of the SDC system to s 300*F (instead of 325"F).
The May 5 and July 7, 1994-submittals provided clarifying information which did not change the initial proposed determination of no significant hazards consideration published in the Federal Reaister dated August 18, 1993 (58FR43924).
These proposed changes integrate various requirements from the Combustion Engineering Standard Technical Specifications (CESTS), Combustion Engineering Restructured Standard Technical Specifications (CERSTS), NRC Generic Letter (GL) 88-17, " Loss of Decay Heat Removal," and specifics of the Palisades SDC system design configuration.
The proposed change does not permanently resolve the high pressure safety injection (HPSI) pump operability issue as proposed in GL 88-17. The Generic l
Letter recommends a HPSI pump be available within 30 minutes for inventory additions to the PCS whenever the PCS water level is in reduced inventory operating conditions.
The licensee has committed to providing a permanent resolution for this recommendation in the form of a TS Change Request.
Current plant equipment design, support analysis, and TS require both HPSI pumps to be rendered inoperable whenever PCS temperature.is <300*F to meet 10 CFR Part 50, Appendix G, low temperature overpressure protection requirements.
At this point in time, no specific and consistent method is either available or proposed by the Combustion Engineering Owners Group for potential incorporation in the CERSTS on how to properly integrate these two requirements.
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9408180005 940812 DR ADOCK 050002 5
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! Consumers Power Company has requested that permanent resolution of HPSI pump operability be delayed until submittal of the Palisades Restructured STS.
t 2.0 EVALUATION i
New Section 3.1.9, " Shutdown Cooling," is being added to the PCS section of the Palisades TS.
This section contains operability requirements for systems and equipment which perform the SDC functions whenever PCS temperature is
<300"F and fuel is in the reactor.
The current TS do not contain provisions for SDC system operations with PCS temperature in this range.
The licensee has been operating the plant with administrative controls in place, identical i
to the proposed license amendment.
1 The proposed changes integrate various requirements From:
(a) Combustion Engineering Standard Technical Specifications (NUREG-0212, Revision 3, draft),
(b) Combustion Engineering Restructured Standard Technical Specifications (May 1989), (c) Generic Letter (GL) 88-17, " Loss of Decay Heat Removal," and (d) the unique design of the SDC system.
The Palisades SDC system design is unlike newer plants in that some piping and other components are common to both SDC trains; however, the degree of redundancy which exists is adequate. The SDC system has a common suction line from the PCS to two SDC pumps which also function as the low pressure safety injection (LPSI) pumps.
The discharge of the pumps is directed to a common header which in turn splits to each of two heat exchangers and then returns to a common header before again dividing into the four LPSI piping headers to the PCS cold legs.
Proposed TS Section 3.1.9 provides SDC operability requirements for three plant conditions.
(1)
PCS Temperature > 200*F and < 300*F (2)
PCS Temperature 1 200*F - Loops filled (3)
PCS Temperature 5 200"F - Loops not filled Section 3.1.9.1 Section 3.1.9.1 is almost identical to the STS for Mode 4 operation (the Palisades plant has " custom" TS which do not utilize the common " Mode" designations for.TS applicability).
Two minor differences were identified.
(1) With no SDC loops operable, the plant is not required to cool down to
< 200*F.
(2) With no PCS loops operable, the time to cooldown to < 200*F is 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (versus 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />).
A requirement for plant cooldown to < 200*F with no SDC trains operable would be impractical.
Normally, in this condition, a PCS loop would be operating to
. remove decay heat via a steam generator with the PCS loop temperature greater than 200*F.
Since the PCS normally operates above 200*F, this is acceptable.
The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> action statement requirement for cooling down the plant with no PCS loops operable is consistent with action times in other Palisades " custom" TS, and STS action requirement. Therefore, these changes are considered acceptable.
Section 3.1.9.2 Section 3.1.9.2 is a combination of the CE STS 3.4.1.4 (NUREG-0212) and 3.4.7 (NUREG-1432) for Mode 5 operation.
The licensee has " custom" TS for the Palisades plant which do not utilize the common " Mode" designations. Two differences were identified.
(1) The licensee has included a provision to allow both the operating and operable SDC loop to be inoperable for the purpose of performing necessary testing and maintenance on valves or piping which are common to both SDC trains.
This provision maintains the SDC flow path while permitting testing and maintenance on shared systems.
The plant was licensed with a common set of heat exchangers for the emergency core cooling system (SDC is a subsystem) and containment spray system.
The licensee has included sufficient controls to manage this type of evolution.
The temperature limitation of 200*F normally would prohibit use of this provision after an extended operating cycle.
In order to use this provision, the licensee closely monitors / trends the core heat output, to project the time to exceed 200*F.
Comparisons of the duration for the planned activity and projected time to 200*F is made to confirm that the test or maintenance activity can safely be performed.
By letter dated August 24, 1992, the licensee provided examples and clarifications of typical situations during testing and maintenance when this provision would need to be exercised. The licensee has demonstrated that the inoperable condition is of short duration and relatively infrequent.
The temperature rise is well below the 200*F limit (and usually below 150*F) and adequate administrative controls are in place to assure proper management of the evolutions. The July 7, 1994, letter limited the inoperable condition to two hours.
Because of the unique design features of Palisades and the attendant administrative controls, we find the provisions in Section 3.1.9.2 acceptable.
(2) The licensee did not include the limitations stated in the CE STS 3.4.1.4 (NUREG-0212) and 3.4.7 (NUREG-1432) pertaining to starting a primary coolant pump.
These limitations are included in Palisades TS Section 3.1.1.h - Amendment Number 131.
Section 3.1.9.3 Section 3.1.9.3 is a combination of the CE STS 3.9.8.1 and 3.9.8.2 (NUREG-0212) and 3.9.4 & 3.9.5 (NUREG-1432) for Mode 6 of operation. Two differences were identified.
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(1)
Paragraph 1 of Section 3.1.9.2 applies to the section.
In addition, Region III inspection report 50-255/91-18 at paragraph 5.b reviewed a surveillance test that secured the heat exchanger from the SDC system.
Sufficient administrative controls were in effect to maintain flow and prevent an inadvertent loss of SDC.
(2) The licensee did not provide a provision to stop all activities that increase core heat load when all SDC flow is lost.
However, the Action statement of Section 3.1.9.3 accomplishes the same function.
The provisions in Section 3.1.9.3, therefore, are acceptable.
Section 3.7.3 Section 3.7.3, " Electrical Systems - Shutdown Cooling Electrical Requirements," and its basis was proposed to be added to the TS to ensure the operability of at least the minimum specified power sources and associated distribution system in support of shutdown operation. With zero or one SDC train required operable, the appropriate engineered safeguards bus shall be operable and capable of being supplied by its normal and emergency power source (diesel generator).
With two trains of SDC required operable, both trains will be powered primarily by normal power source, with the added requirement of an operable emergency power source available.
These electrical system requirements provide some necessary redundancy to maintain one SDC train operable, in the event of the loss of a normal or emergency power source, thereby providing the necessary heat removal function.
Therefore, these changes are considered acceptable.
Several additional changes to existing TS are necessary to establish new SDC operability requirements. The licensee performed a review of SDC piping stresses analyses and determined that the system has only been analyzed up to 300*F.
Accordingly, the licensee modified its original SDC license amendment (by letter dated May 1, 1991) to restrict operation of the SDC system to PCS temperatures less than or equal to 300*F.
Also, changes were proposed to existing steam generator operability requirements to ensure the PCS can be
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cooled down to 300*F (that temperature which the decay heat removal function could be transferred to the SDC system).
The following TS changes are necessary to correct those specifications that refer to the previous 325*F SK '.emperature limit:
Change Section 3.1.1.d to read "Both steam generators shall be capable of performing their heat transfer function whenever the average temperature of the primary coolant is above 300*F."
Change the first line of Section 3.1.1.1 to read "The PCS shall not be j
heated or maintained above 300*F...."
Change the first line of Section 3.5.1 to read "The primary coolant shall not be heated above 300*F unless the...."
. Change the first line of Section 3.5.2 to read "With the Primary Coolant System at a temperature greater than 300*F,...."
Change the first line of Section 3.5.3 to read "With the Primary Coolant System at a temperature greater than 300*F,...."
Change the first paragraph of Section 3.7.1 to read "The primary coolant system shall not be heated or maintained at temperatures above 300*F if the following electrical systems are not operable:"
On Table 3.17.4, Items Nos. 9, 12, 13, 14, 15, and 18, change the Permissible Bypass Conditions columns to read "Not required below 300*F."
Change Table 3.24-2, Item 5.a, in the Applicability column to read, "Above 300*F."
In Section 3.25.1, change the end of the sentence of the Limiting Condition for Operation to read "in accordance with Section 4.21."
- Also, change the applicability statement to read:
" Reactor coolant temperature
> 300*F."
Change Note (1) at tne end of Table 4.21.1 to read:
"(1) Quarterly checks are not required when the PCS temperature is 300*F."
Change Table 4.24-2, Item Sa, in the Modes in Which Surveillance Required column to read "Above 300*F."
The above changes correct the TS to match actual plant design.
The current operating procedures restrict SDC operation to less than or equal to 300*F.
The original operating procedures restricted SDC operation to less than or equal to 325'F.
Per telephone conversation with the licensee on June 17, 1992, the operating procedures were changed during the 1970's for conservatism to ensure the 325*F limit was not violated.
The system analysis / stress calculations performed per IE Bulletin 79-14 were based on the 300*F requirement in the (at that time) existing operating procedures. Therefore, t h r -vo r has been reanalyzed to 300*F; however, for some time prior to and t.T te 9 t aalysis was required and performed, the system has been operated with". @ oo-eating limit of 300*F.
6be, tM capW1ity of the plant to adequately cool down to 300*F using the v.am cenerat: s was discussed and verified.
Maintaining the decay heat removal car t tity with the steam generators to 300*F is acceptable.
STS l
recognized that the decay heat removal can be performed by either of the primary loops (operable primary coolant pump and steam generator).
Therefore, the changes to the TS restricting SDC operations to less than or equal to 300*F, and imposing requirements to ensure the PCS can be cooled by the steam generator at temperatures greater than 300*F are considered acceptable.
Table 4.2.2, " Minimum Frequencies for Equipment Tests" has been expanded to include surveillance requirements to verify SDC operability.
If reactor coolant pumps are required to be operable, and are not in operation, a weekly 1
breaker alignment and power availability surveillance is required.
Also, when the steam generators are required operable (as part of an operable PCS loop),
the associated secondary water level is required to be verified once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> above the required setpoint of -84%.
, Finally, coolant loop or train flow shall be verified at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
These surveillance requirements are consistent with those required by STS and are considered acceptable.
Editorial Corrections The following two editorial corrections have also been made:
The title to Figure 3.0 on page i, Table of Contents, has been corrected to reflect the actual figure title as changed in Amendment 143; and the notation "(Next page is 4-90)" has been deleted from page 4-88 to reflect pages deleted in Amendment 154.
Palisades' commitment to formal industry position In response to our March 12, 1993, letter requiring written verification of Palisades' commitment to the formal industry position related to shutdown plant issues, the licensee provided the following commitment in its letter dated May 19, 1993:
(1) Palisades has assessed current practices, using NUMARC 91-06,
" Guidelines for Industry Action to Assess Shutdown Management," to plan outages, and (2) Palisades has implemented improvements adopted as a result of the assessment.
We find the submitted verification acceptable.
3.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Michigan State official was notified of the proposed issuance of the amendment.
The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes requirements with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements.
The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding (58 FR 43924).
Accordingly, this 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 this amendment.
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5.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: J. Heller, A. H. Hsia Date: August 12, 1994 i
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