ML17252B505

LER 77-050/03L-0 for Dresden, Unit 2 Re Local Leak Rate Test of Drywell Personnel Air Lock During Refueling

ML17252B505
Person / Time
Site:	Dresden
Issue date:	11/03/2017
From:	Stephenson B Commonwealth Edison Co
To:	James Keppler NRC/RGN-III
References
BBS LTR 1030-77 LER 77-050/03L-0
Download: ML17252B505 (3)

Text

{{#Wiki_filter:Commonw. Edison Dresden Nuclear Power Station R.R. #1 Morris, Illinois 60450 Telephone 815/942-2920

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Novembe}'." i ~'~); 1977 BBS LTR t/1030- 77

                                                                                                 ~j J
                                                                                                 -: i James G. Keppler, Regional Director Directorate of Regulatory Operations - Region III U.S. Nuclear Regulatory Connnission 799 Roosevelt Road Glen Ellyn, IL           60i37
            . Reportable Occurr~nce Report #77-050/031~0, _Docket #050-0237 is

• hereby submit~ed to yotir off ic~ in a~cordance with Dresden Nuclear Power Station Technical Specifications 6,6,B,2,d., abnormai degra-dation of systems designed to contain radioactive material result-.:-

ing from: :the f.ission process,

                                                     ~.B. Stephenson i-  ~tation Superintendent Dresden Nuclear Power Station*

BBS:dlz Enclosure cc: Director of Inspection & Enforcement Director of Management Information & Program Control File/NRC

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1 \911 I

N"Ftc~~ 17-77) e 'LICENSEE EVENT REPORT e CONTROL BLOCK:

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I ' I I 610' (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

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7 . 8 r1 1 L 1n1R 1s 9 LICENSEE CODE 1 2 101 14 15 o 1 o 1 *. 1 o 1 o 1 o 1 o 1 o 1 LICENSE NUMBER

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25. 26 LICENSE TYPE ;JO I I G) 57_ CAT 58 CON'T .

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• 8 60 61 DOCKET NUMBER 68 69 EVENT DATE 74 75 . REPORT DATE 80*

EVENT DESCRIPTION AND PROBABLE CONSEQUENCES (,0) . [Q:ITI I. During local leak rate test of Drywill personnel,;.~ir lock during refueling, measured leakage was 40.207 SCFH. Leakage :was found through the inner door equalizing valve [QTIJ (ie, Drywell to airlock). Assuming all leakage was through this valve. T.S.4,7.A.2,f, [2TIJ (2),(b) single valve leakage limit (5%'.Cto

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                                                                                                                        = 29,3 SCFH) was exceeded.                             This event had little safety significance since the penetration through leakage was less than the
  ~

T.S. limit, This is the first event involving excessive leakage through an air lock

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   ~ L-~v_e_n_t_v_a_l_v_e_.__________~-~~------------~---~-----~~-~

7 8 9 80 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE [ill] 15 IA I@ L!J@ ~@) vi Al LI VI El x1@ ~@) ~@ 7 8' 9 10 11 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT REVISION

                 ~         LER/RO LVENT YEAR                                         REPORT NO.                           _              CODE              TYPE                           NO.
                 ~ REPORT NUMBER I I I7 7                 I I            1°151°1                           1.....-1          I Ol   31           ~              l.=J           ~

21 22 23 24 26 27 28 29 30 31. 32 ACTION FUTURE EFFECT SHUTDOWN (.:;::;\ ATTACHMENT NPRD-4 PRIME C.OMP. COMPONENT TAKEN ACTION ON PLANT METHOD HOURS ~ SUBMITTED FORM SUB. SUPPLIER MANUFACTURER

                 ~@~@)                                ~@                 ~                I    01 01 01 01                       L!!J@          LIU@              ~              I JI o 1*1 I q@

33 34 35 36 37 40 41 42 43 44 ' 47, CAUSE DESCRIPTION AND CORRECTIVE ACTIONS @ o::I]] I The leaking valve was disassembled, The valve seating surfaces were found to be dirty;j Also, outer seats were loose. The valve was cleaned and reassembled. The personnel air lock wa~ retested with a measured leak rate of 15,912 SCFH which is within the T.s.1 ITITI [ill] L.I_1_i_m_i_t_.__N_o_f_u_r_t_h_e_r_a_c_t_i_on __i_s_r_e..:q..:u_i_r_e_d_.__T_h_e_v_e_n_t_v_a_l_v_e_i_s_a_3_i_n_c_h--']::i_a_1_1_*v_a_lv_e_m_o_d_e_l_ __. 113 D22NN. ITill 7 8 9 80 FACILITY METHOD OF A STATUS  % POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION ~ Em 8 L!J@ I 0 I 0 I 9 10 ' 0 l@) I.....___N_A_ __, 12 13 L.!J~~l ___L_o_c_a_l_._L_e_a_k_R_a_t_e_T_e_s_t_in_g;;__*_ _ _-'-___. 7 44 45 46 80 AC.TIVITY CONTENT ~ RELEASED OF RELEASE AMOUNT OF ACTIVITY~ LOCATION .OF RELEASE@ [2li] ~ @) ~@I NA ,___________________N_A________________,I 7 8 9 10 11 44 45 80 PERSONNEL EXPOSURES Q\ NUMBER A TYPE DESCRIPTION [iI2J I 0 ., 0 I 9J6LJJ@L.,.-______________NA_ _ _...,.-_ _ _ _ ____, 7 8 9 11 12 13 80 PERSONNEL INJURIES (,;:;\ NUMBER DESCRIPTION~ ITfil I o I ol ' 7 8 9 o l @ " - - - - - - - - - - - - - - - - - _ , ; ; , ; N = A_ _ _ _ _ _ _ _ ___. 11 12 80 LOSS OF OR DAMAGE TO FACILITY t4J\ TYPE . DESCRIPTION . ~

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