ML18066A627

LER 98-011-01:on 981217,inadequate Lube Oil Collection Sys for Primary Coolant Pumps Was Noted.Caused by Design Change Not Containing Appropriate Level of Rigor.Exemption from 10CFR50,App R Was Requested.With 990902 Ltr

ML18066A627
Person / Time
Site:	Palisades
Issue date:	09/02/1999
From:	Dotson B, Thomas J. Palmisano CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-98-011, NUDOCS 9909080074
Download: ML18066A627 (5)

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A CMS Energy Com~ny Palisades Nuclear Plant Tel: 616 764 2296 27780 Blue Star Memorial Highway Fax:.616 764 2425 Covert, Ml 49043 September 2, 1999 U.S. Nuclear Regulatory Commission ATTN: Document Control De$k Washington, DC 20555

. DOCKET 50-255 - LICENSE PPR PALISADES PLANT REVISED LICENSEE EVENT REPORT 98-011-01, INADEQUATE LUBE OIL COLLECTION SYSTEM FOR PRIMARY COOL.ANT PUMPS Revised Licensee Event Report (LER) 98-011-01 is attached. The LER describes a eondition in which the oil colledion system for the primary coolant pump motors required by 10 CFR 50, Appendix R, Sedion 111.0, is inadequate. This condition is reportable to the.NRC in acccirdance with 10 CFR 50.73(a)(2)(ii)(B) as a condition outside the design basis of the plant

SUMMARY

OF.COMMITMENTS This letter contains no new commitments and no revisions to existing commitments .

• ~/?~

.Thomas J. Palmisano

":;_;Site Vice, President

. CC AdministratQr, Region Ill, USNRC Projed Manager, NRR, USNRC NBC Resident Inspector - _Palisades Attachment

NRCFORM388 U.S. NUCLEAR REGULA TORY COMMISSION APPROVED BY OMB NO. 315~104 (4195) EXPIRES 4130/98 ESTIMATEO BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INF~TION cou.ECllOH REQUEST: 50.0 ~S. REPORTED LESSONS LEARNED ARE INCORPORATEO INTO THE LICENSING PROCESS ANO FED BACK TO INDUSTRY.

LICENSEE EVENT REPORT (LERi FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION ANO RECORDS MANAGEMENT BRANCH (T_. F33). U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON. DC ~1. ANO TO THE PAPERWORK REDUCTION (See reverse for required number of digits/characters for each block) PROJECT(31~10<. OFFICE OF MANAGEMENT ANO BUDGET. WASHINGTON. DC 20503 FACILITY NAME (1) CONSUMERS ENERGY COMPANY DOCKET NUMBER (2) Page (3)

PALISADES NUCLEAR PLANT 05000255 1of4 TITLE (4)

LICENSEE EVENT REPORT 98-011-01, INADEQUATE LUBE OIL COLLECTION SYSTEM FOR PRIMARY COOLANT PUMPS EVENT DATE l5\ LER NUMBER l6\ REPORT DATE m OTHER FACILITIES INVOLVED l8)

MONTH DAY YEAR YEAR I SEQUENTIAL NUMBER REVISION NUMBER MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 05000 FACILITY NAME DOCKET NUMBER 12 17 98 98 011 01 09 02 99 05000 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check one or more) (11)

MODE(9) N 20.2201(b) 20.2203(a)(2)(v) 50. 73(8)(2)(1) 50. 73(8)(2)(iii)

POWER

• 20.2203(8)(1) *20.2203(8)(3)(1) x 50. 73(8)(2)(11) 50. 73(8)(2)(x)

LEVEL.(10) 0 20.2203(1)(2)(1) 20.2203(8)(3)(0) 50. 73(8)(2)(111) 73.71

50. 73(8)(2)(1v) OTHER 20.2203(1)(2)(0) 20.2203(8)(4) 20.2203(1)(2)(111) 50.38(c)(1) 50. 73(8)(2)(v) Specify In Abstract below 20 ~8\~\llv\ 50.38lclt2l 50.73l8\1'2\tvll\ or In NRC Fonn 366A ...

LICENSEE CONTACT FOR THIS LER (12)

NAME Barbara E. Dotson, General Technical Analyst TELEPHONE NUMBER (Include Area Code)

(616) 764-2265 COMPLETE ONE UNE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT t13l CAUSE 8VSTEM COMPONENT. MANUFACTURER REPORTABLE . CAUSE SYSTEM COMPONENT MANUl'ACTURER REPORTABLE TONPRDS TONPRDS B LL RVR N SUPPLEMENTAL REPORT EXPECTED t14) MONTH DAY YEAR I YES If WIS, COMPLETE EXPECTED COMPLETION DATE

• x I NO EXPECTED SUBMISSION DATE (15\

ABSTRACT (Limit to 1400 spaces, Le., approximately 15 linglHpaced typewritten lines) (16) 10 CFR 50 Appendix R, Section 111.0, requires that each of the primary coolant pump (PCP) motors be provided with a lube oil collection system and that Its associated collection tank be sized to contain the entire lube oil system Inventory of the PCP motor. Contrary to the above, on December 17, 1998, with 1:t1e plant in cold shutdown, the PCP motor lube oil collection tanks were discovered to be undersized with respect to their ability to hold a PCP motor's entire lube oil system inventory. The discrepancy applies to the lube oil collection tank for each of the four PCPs.

This condition is reportable in accordance with 10 CFR 50.73(a)(2)(ii)(B) as a condition outside the de8ign basis of the plant* -

This condition has low safety significance. The collection tank is large enough to collect any random leakage associated with normal operation. For a single catastrophic lube oil system failure, a relatively small amount of oil would overflow from the collection tank and be directed to the floor area in the *vicinity of the collection tank away from any potential ignition source. Therefore, any overflow would not create a fire hazard.

NRC FORM 366a - -* . -. U.S.-NUCLEAR REGULATORY COMMISSION 4/95 LICENSEE EVENT REPORT (LER) g TEXT CONTINUATION FACILITY NAME 11\ DOCKET!21 LER NUMBER 6l CONSUMERS ENERGY COMPANY 05000255 YEAR I SEQUENTIAL NUMBER REVISION NUMBER 4

PALISADES NUCLEAR PLANT 98 011 01 TEXT (If more space 1s required, use add1t1onal copies of NRC Form 366A) (17)

EVENT DESCRIPTION 10 CFR 50 Appendix R, Section 111.0, requires that each of the primary coolant [AB] pump [P]

motors [MO] be provided with a lube oil collection system and that its associated collection tank

[TK] be sized to contain the entire lube oil system [LL] inventory of the primary coolant pump (PCP) motor. Contrary to the above, on December 17, 1998, with the plant in cold shutdown, the PCP motor lube oil collection tanks were discovered to be undersized with respect to their ability to hold a PCP mbtor's entire lube oil system inventory. The discrepancy applies to the lube oil collection tank for each of the four PCPs.

• This condition is reportable in accordance with 10 CFR 50.73(a)(2)(ii)(B) as a condition outside the design basis of the. plant.

ANALYSIS OF EVENJ

• -- in December 1998, it was identified that the oil collection.tanks could not hold the combined contents of,the PCP upper and lower motor lube oil reservoirs. In May 1999, it was identified that the installed hand pump suction lines for removing oil from the coll~ction tanks do not extend to the tank bottom, thus further reducing the usable volum~ of the oil collection tanks due to the

• volume of oil which would remain in the tanks. Tank dimensions field verified at this time also resulted in a slight further reduction in usable tank volume. The primary result of this additional information was the discov~ry that the usable volume of an oil collection tank is not sufficient to*

contain the entire volume of oil stored in a PCP upper oil reservoir.

The lube oil* system for a PCP motor consists of independent upper and lower reservoirs, lube oil coolers and associated pipi"g. As a result, the maximum lube oil volume from any single failure wou.ld be the entire contents of either the upper reservoir or the lower reservoir, but not both.

• The upper PCP motor oil reservoir, cooler and associated piping can contain up to;approximately 87 gallons of oil. The lower PCP motor oil reservoir, cooler and associated piping can contain up to approximately 18 gallons*of . oil. The total motor lube oil inventory is 105 gallons.

Each collection tank is sized to hold approximately 84. gallon$ of lube oil. A collection tank that has been emptied by its hand pump, will retain approximately five gallons of oil in the bottom of

• the tank since, as stated above, the pump suctio_n line for removing oil does not extend to the

• bottom of the tank. Therefore, the usable collection tank volume is appr<?ximately 79 gallons. -

Consequently, each lube oil collection tank is undersized by approximately 26 gallons (105 - 79) with respect to its ability to hold a PCP motor's entire lube oil inventory. For a singl~ worst case

NRC FORM 366a U.S. NUCLEAR REGULA TORY COMMISSION 4/95 LICENSEE EVENT REPORT (LER) g TEXT CONTINUATION FACILITY NAME (1) DOCKET<2\ LER NUMBER 6\

CONSUMERS ENERGY COMPANY YEAR I SEQUENTIAL NUMBER REVISION NUMBER PALISADES NUCLEAR .PLANT 05000255 4 98 011 01 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) leak of the upper reservoir system, the collection tanks are undersized by approximately 8 gallons (87 - 79). The collection tanks have sufficient usable volume to accommodate a single worst case leak in the lower reservoir (18 gallons vice usable volume of 79 gallons).*

PCP motor lube oil level in each reservoir is monitored closely during operation. The quantity of oil in the upper reservoir between the fill level and the low level alarm is approximately 20 gallons.

The quantity of oil in the lower reservoir between the fill level and the low level alarm is

• .approximately fi~e gallons. Procedure controls for lube oil levels below these normal operating ranges require the PCP.:to be shut down. Therefore, despite a collection tank's inability to contain the entire lube oil Inventory of the combined upper and lower reservoirs of a PCP, or even the entire upper reservoir alone, the collection tank is able to meet its design function which is to collect random oil leakage and prevent it from becoming a fire hazard.

SAFETY SIGNIFICANCE This condition has low safety significance. The size of each collection tank is large enough to collect any random leakage associated with normal operation. Since the upper and lower lube oil systems for a PCP are separate, it is not considered credible that both systems would catastrophically fail simultaneously. Therefore, the worst case scenario is failure of an upper

• • .reservoir oil system with an entire loss of its oil inventory. Any oil that would overflow the collection tank in this instance, would be directed to the floor in the vicinity of the collection tank,

• -- -where no source of ignition exists (the floor surface is relatively cool, approximately 100 degrees F, c;ompared to *the 400 degrees F lube oil flash point). Therefore, a fire hazard eould not result from a .P~t*:mtiiil overflow of the collection tank. -

The design change process in place at the*time of the original installation (early 1980s) did not contain an appropriate level of rigor. Consequently, the design information was no~ appropriately validated and the erroneous assumptions were carried forward.

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• • coRRECTIYE ACTIONS An exemption from the 10 CFR 50 Appendix R requirements is being pursued for the existing collection tank design. *

• The design change process has evolved significantly since the early 1980s including implementation of multi-disciplinary design reviews, more rigorous technical reviews and

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NRC FORM 36Sa U.S. NUCLEAR REGULATORY COMMISSION 4/95 LICENSEE EVENT REPORT (LER) g TEXT CONTINUATION FACILITY NAME 11\ DOCKET12l LER NUMBER (6\

CONSUMERS ENERGY COMPANY 05000255 YEAR I SEQUENTIAL NUMBER I REVISION NUMBER 4

PALISADES NUCLEAR PLANT 98 011 01 TEXT (If more space 1s required, use additional copies of NRC Form 366A) (17) increased emphasis on post-modification testing. Therefore, no further corrective actions are prescribed for the design change process as the result of this occurrence.

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