ML20216J908

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Forwards Revised Written Event Rept 99-10,rev 3,pertaining to Corroded Fire Sprinkler Heads Affecting Operability of high-pressure Fire Water (HPFW) Sprinkler Sys.No Commitment Contained in Rept
ML20216J908
Person / Time
Site: Paducah Gaseous Diffusion Plant
Issue date: 09/30/1999
From: Pulley H
UNITED STATES ENRICHMENT CORP. (USEC)
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GDP-99-1036, NUDOCS 9910060331
Download: ML20216J908 (5)


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dy USEC A Global Energy C September 30,1999 :

L GDP 99-1036 i

United States Nuclear Regulatory Commission

' Attention:. Document Control Desk.

Washington, D.C. 20555-0001

,i Paducah Gaseous Diffusion Plant (PGDP).

Docket No. 70-7001 Event Report ER-99-10, Rev. 3 l

Pursuant to 10CFR76.120(d)(2), enclosed is the revised written event report pertaining to corroded fire sprinkler heads affecting the operability of high-pressure fire water (HPFW) sprinkler systems.

The Nuclear Regulatory Commission (NRC) was notified of the initial event on June 3,1999 (NRC No. 35790)'and updated, as other notifications became necessary. At this time, the testing and analysis to determine the root cause and corrective actions necessary have not been completed.

Vertical bars in the right hand margin indicate changes to the last repor dated August 26,1999.

There are no commitments contained in this report.

Any questions regarding this matter should be directed to Larry Jackson at (502) 441-6796.

Sincerely, AI\\

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loward ley /

j General Manaper - -

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Paducah Gaseous Diffusion Plant

Enclosures:

As Stated :

cc: NRC Region III OfTice NRC Resident Inspector - PGDP i

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9910060331 990930 POR ADOCK 07007001 C

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P.O. Box 1410, Paducah, KY 42001 Telephone.502-441-5803 Fax 502 441-5801 http://www.us.:c. corn i

L Offices in Livermore, CA 1%ducah, KY Portsmouth, OH Washington, DC L -.

p Docket No. 70-700t GDP 99-1036 Page 1 of 4 EVENT REPORT ER-99-10, Rev. 3 l

DESCRIPTION OF EVENT On June 2,1999, at approximately 1630 hrs., Fires Services personnel notitled the Plant Superintendent (PSS) that during the annual Fire Services building high pressure fire wat (HPFW) sprinkler system re-appraisal,66 sprinkler heads in the C-337 process b 16 systems and 20 sprinkler heads in the C-333 process building affecting 1 system were have a build up ofsorrosion products around the body of the heads. The PSS consulted with plants fire protection engineer who could not provide reasonable assurance that the affected sprinkler heads could perform their design function. The PSS then declared the systems i and C-333 inoperable, and established roving fire patrols in the affected areas, as re Technical Safety Requirements (TSR) General Limiting Conditions For Operations (LC 2.4.4.5.

On June 3,1999, at 1330 hrs., the Nuclear Regulatory Commission Headquarter (NRC-HQ) operations office was notified of the event, as required by 10CFR76.120(c)(2)

NRC event 35790 was assigned.

Inspections of the remaining Cascade process building sprinkler systems were initiated to determine if other systems exhibited similar prob! cms. Th resulted in the discovery of-two sprinkler heads in the C-335 process building, which had similar corrosion deposits affecting the operability of one system. This system was declared inop and LCO actions to establish a roving fire watch were implemented. At 0922 hrs., on June 4, 1999, NRC-HQ operations office was notified, as required by 10CFR76.120 (c)(2) and NRC No 35790 was updated to provide this additional information.

Subsequent to these notifications, investigation team members on June l

16, 1999, identified corrosion on eight sprinkler heads in C-333. The effected systems were declared inoperabl fire watches were implemented. NRC-HQ was notified and the event report (NRC No. 3579

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was updated on June 17,1999.

On June 18,1999, this report was again updated and NRC-HQ notified to repon the discove

'I three sprinider heads in the C-333.

4 On June 25, 1999, the report was updated and NRC-HQ notified to report five additional sprinkler heads in C-337 with similar corrosion.

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Docket No. 70-7001 GDP 99-1036 Page 2 of 4 On July 30,~ 1999, this report 'was updated and NRC-HQ notified when five additional corroded sprinkler heads were discovered in C-337. On July 31,1999, two additional corroded sprinkler heads were discovered in C-337. NRC-HQ was notified and the report was again updated.- On

' August 10, 1999, two corroded sprinkler heads were discovered in C-337 and NRC was ' notified

~ and the report updated. On August 22,1999, four corroded ' sprinkler heads were discovered in C-333. On August 28,1999, two adjacent sprinkler heads were discovered in C-337 system D-

-11; August 29,1999, two adjacent heads were discovered in C-337 system D-15 and system D-7 10; and on September 30,1999, two adjacent sprinkler heads were discovered in C-333 in system x

iB-15. NRC-HQ was notified and this report updated. The total number of corroded heads below

- exceeds the numbefs stated above, because operability of the system may not depend on a single T head. l-A specific operability determination is conducted when a' corroded head is found and includes the number of corroded heads and location.

. For all of the above discoveries, the systems were declared inoperable, LCO actions initiated and actions were immediately initiated to replace the sprinkler heads affecting system ' operability and following completion of this work, the systems were declared operable and LCO actions were

- exited.

The HPFW sprinkler systems in the process buildings are wet-pipe systems installed in the 1954 timeframe. The total number of sprinkler heads with external' mineral deposits discovered to date in 1999 is 133. The breakdown by building is: (number of corroded heads / total heads) C-310

=.0/606; C-315 = 0/92; C-331 = 0/12,610; C-333 = 47/24,877; C-337== 118/24,7%; C-335

= 2/13,368.

~ The replacement of sprinkler heads with corrosion deposits, which may affect the HPFW systems operability, provides reasonable assurance that the system can perform its intended function.

' CAUSE OF EVENT -

Although thS analysis to determine the root cause of the event has not been completed,

. preliminary results indicate that the deposits discovered on the sprinkler heads are the results of water leakage and ' subsequent evaporation.. The' deposits appear to be salts associated with typical constituents of the sprinkler system water chemistry, e.g., calcium, chloride, and sodium. It appears that the leakage is caused by corrosion of the interior copper gasket,' which is designed to provide a' seal between the body of the sprinkler heaaand the sprinkler " cap" or " button" (see attached diagram). The analysis to determine the cause of the button deterioration and the effect of the resulting deposits on the heads operability has not been completed. The USEC plant at Portsmouth,. Ohio is. involved in the investigation and the issue has been discussed with a representative of the Factory Mutual (FM) Insurance Company and Grinnell Corporation.

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Docket No. 70-7001 1 -

GDP 99-1036 Page 3 of 4 1

j L In addition to the testing ongoing at Paducah and Portsmouth, FM has agreed to con]

at their laboratories to provide their expertise in this area. Several sprinkler heads have been L

removed from the HPFWS and 'sent to the FM metallurgy and hydraulics' laboratories for testin i

The.results of: FM's hydraulics test on'12 sprinkler heads submitted by PGDP have been

receivedc; FM tested each head in their air oven sensitivity testing apparatus. Each head was screwed into the air' o'ven's water tes' t connection. The water pressure was adjusted to 5 psi and
the air oven temperature rate-of-rise controller was then regulated to follow a temperature / time test prot 6 col to evaluate the sprinkler's operation sensitivity response. Six of the 12 sprinklers Lresponded satisfactorily, i.e. actuated at or below 212* F and expelled the cap flowing water, as.
designed. Two o'f these sprinklers did not have visible mineral deposits. The remaining l

sprinklers, all-of which exhibited external mineral deposits, actuated at approximately 212' F, but-failed to eject their cap and gaskets at the required 5 psi water pressure. They required L

. increasing' pressure of 15 psi (2 sprinklers),' 30 psi (1 sprinkler) 55 psi (1 sprinkler) and 120 psi (2' sprinklers) to dislodge their cap'and gasket.

From these tests FM considered these 6

. sprinklers unreliable for automatic fire protection service. Three other heads were sent to FM's i

metallurgy labs for testing. The results of their metallurgy lab tests have not been received.

LA statistically based sprinkler head-sampling plan has been completed and approved. This will' provide _a method by.which sprinkler heads will be endomly chosen and removed from the spstem for analysis and' testing. This will include the removal of heads exhibiting the external mineral deposits and heads that do not. A laboratory procedure has been created to provide the,

controls for the testing bf the heads'that are removed. The results of this testing will be used to L

determine the overall effect of this problem on the HPFWS.

/In. addition, representatives from the BetziDearborn Water Management Group have visited the j'

plant and have been requested to provide tiseir expertise to assist in determining the cause of the

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deterioration of the sprinkler heads copper gasket. They have agreed to assist in the development L

of a firewater-sampling plan and have made some recommendations. This water sampling and iy analysis will aid in determining the cause and scope of the water chemistry problem. Water -

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! samples have been drawn from various selected fire sprinkler systems, the cooling tower basins

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' and HPFW tank and'sent to Betz for analysis. The' results of this and the sprinkler head testing effort will be used to determine the cause,.the effect, and the corrective ' actions necessary to

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correct the problem. This report will be revised as the results of the testing and analysis becomes

' available. ~ A target'date for the next revision is November 5,1999.

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l Docket No. 70-7001 i

GDP 99-1036 Page 4 of 4

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EXTENT OF EXPOSURE OF INDIVIDUALS TO RADIATION OR TO RADIOACTIVE MATERIALS This event does not involve radioactive materials and no exposures have occurred.

l LESSONS LEARNED To'Be Determined l

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