ML20196D468

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Rev 4 to Mechanical Sys Review Issues List
ML20196D468
Person / Time
Site: Comanche Peak  Luminant icon.png
Issue date: 02/09/1988
From:
CYGNA ENERGY SERVICES
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ML20196D457 List:
References
NUDOCS 8802170150
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2/9/88 Revision 4 Page 1 MECIIANICAL SYSTEMS Review Issues List L Component Cooling Water (CCW) System Maximum Temocrature

References:

1. Cygna Phase 4 Final Report, TR-84056-01, Revision 0, Observation MS-01-01 (not yet issued).
2. N.H. Williams (Cygna) letter to J.B. George (TUGCO),

84056.010, dated July 30, 1984.

3. LM. Poppelwell (TUGCO) letter to N.H. Williams (Cygna), l dated August 11, 1984.
4. N.H. Williams (Cygna) letter to J.B. George (TUGCO), l I

84056.023, dated August 21, 1984.

5. LM. Poppelwell (TUGCO) letter to N.H. Williams (Cygna), 1 dated September 11, 1984. l
6. LM. Poppelwell (TUGCO) letter to N.H. Williams (Cygna), l dated October 1,1984. j l
7. N.H. Williams (Cygna) Letter to . T.W. Beck (TUGCO), I 84056.060, Attachment E dated March 29, 1985. l
8. Iranscript of meeting between TU Electric and Cygna, at Glen Rose, Texas, on April 21,1987.

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9. Communication Reports from Cygna audit July 15-17,1987 at SWEC, Boston office.
10. Communication Reports from Cygna audit August 17 21, 1987 at SWEC, Boston office.

IL Communication Reports from Cygna audit October 19-23, 1987 at SWEC, Boston office. -

12. Communication Reports from Cygna audit Decemlbr 711, 1987 at SWEC, Boston office.

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2/9/88 Revision 4 Page 2 Summary: Cygna noted discrepancies between the Westinghouse stated maximum CCW system temperature of 1200F and

1) the CPSES FSAR;
2) Gibbs & Hill Calculation 233-16; and i
3) Gibbs & Hill Calculation 229-14. i These documents indicated maxima of 121.80F,1350F and 129.7 F, respectively. TU Electric provided documentation that showed the acceptability of the 1350F maximum temperature. Some of this i documentation is dated as late as September 28, 1984, indicating  !

that TU Electric may not have been aware of the problem prior to I the Cygna questions. In Revision 3 of the Review Issues List, l Cygna stated that TU Electric or Gibbs and Hill should demonstrate that, when design and operating data is revised, all existing system components are reviewed to ensure that they meet ,

the new operating conditions. l i

In Reference 8, TU ElecHe provided information that in general j i

described a process for reviewing the effects on systems and components due to changes in deaga or operating data. The j

process and provisions described have been discussed during both the July 15-17, 1987 and the August 17-21,1987- review sessions at j the Stone and Webster Engineering Company (SWEC) office in i Boston (References 9 and 10), i

~Although Cygna stated that the documentation provided by TU Electric, showing acceptability of the 1350F CCW HX outlet b temperature was sufficient to close out the observation, the new Design Basis Consolidation Program (DBCP) has necessitated a revisit of this issue. In particular, it is not clear that the heat exchangers were evaluated at system maximum temperature,1350F, for heat removal capacity and subsequent effects on interfacing systems. Design loads and performance envelopes for CCW Components had not as yet been confirmed (Reference 7, Attachment E, Item 2.1.)

Response: As part of the overall DBCP, SWEC is verifying the CCW temperatures. They performed their own analyses including new flow distribution calculations which affect the temperature calculations. SWEC inputted various system configurations into their flow and heat balance calculations which should be the bounding scenarios or modes of operation, including those expected Texas Utilities Electric Company Comanche Peak Steam Electric Station

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l 2/9/88 Revision 4 Page 3 to yield CCW system maximum heat loads and temperatures. They are using their own computer program HY-066.

Further, a fluid transient analysis on the CCW system was performed by SWEC. This generic CCW analysis showed that if valve operating times exceeded a certain value, then the induced loads would be acceptable. Those valves with unacceptable closure  :

times (less than 3 seconds) would be modified to increase the closure time (Reference 11).

Status: Open.

Cygna reviewed the preliminary heat and flow balance calculations in Reference 10. Then, during the October and December 1987  ;

review sessions (Reference Nos.11 and 12), enough progress had been made (i.e. calculations had reached the Rev. O status) by SWEC for Cygna to evaluate the methodology used and conclusions reached.

Cygna was satisfied that inputs had been selected from the best available source. Adequate cross-references between the heat A Lm load and flow balance results were documented. SWEC considered all major operating modes, using valid conservative assumptions, and had simulated specific system alignments to yield the "worst case" results, including CCW pump "run out" and "run back" conditions. Major conclusions indicated that the existing CCW .

system,. has excess heat removal capacity and that the maximum CCW. system temperature does not exceed FSAR/ design reqtiirements to perform its safety functions and achieve coohng i within the expected time.  ;

In the few cases that SWEC had determined certain components may receive less flow than original criteria required, SWEC provided documentation supporting their evaluation that the lower-than -design flow rates (i.e. specifically to the most remoti RCP thermal barrier) would not affect system performance or present any functional risk to the component itself. Cygna investigated SWEC's in-house computer program HY-066 (flow distribution) for conformance to quality assurance requirements, and found that proper documentation, tracking and reference records existed.

Although this issue appears to be almost resolved, reconciliation between the fluid flow calculation and the heat transfer i calculation needs to be reviewed for consistency.

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2. CCW Surce Tank Isolation on High Padiation Signal

References:

L Cygna Phase 4 Final Report, TR-84056-01, Revision 0, Observation MS-06-01 (not yet issued).

2. N.H. Williams (Cygna) letter to J .B. George (TUGCO),

84056.028, dated August 27, 1984.

3. LM. Poppelwell (TUGCO) letter to N.H. Williams (Cygna),

dated September 20, 1984.

4. N.H. Williams (Cygna) letter 84056.078, dated August 1,1985.

to J.W. Beck (TUGCO), A

5. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),

84056.088, dated October 16, 1985.

6. W.G. Counsil (TUGCO) letter to R.J. Stuart (Cygna), dated >

September 2,1986.

7. Transcript of meeting between TU Electric and Cygna at Glen Rose, Texas, on April 21, 1987.
8. Transcript of meeting between TU Electric and Cygna at Glen Rose, Texas, on May 19, 1987.
9. . Communications Reports from Cygna audit, July 15-17, 1987 at SWEC, Boston office.
10. Communications Reports from Cygna audit, August 17-21, 1987 at SWEC, Boston office.

l IL Communications Reports from Cygna audit, October 19-23, l 1987 at SWEC, Boston office.

12. Communications Reports from Cygna audit, December 7-11, 1987 at SWEC, Boston office.

Summary: The Westinghouse functional design requirements document-for the I CCW system required that the surge tank be isolated by closing l the vent valve on receipt of a high radiation signal. TU l Electric /Gibbs & Hill removed this control function from the system radiation monitors to prevent spurious actuation caused by rising system temperature during accidents. Since the change did Texas Utilities Electric Company Comanche Peak Steam Electric Station Independent Assessment Program - All Phases L Ji i TUE\23MS.lSSUE.04 llll111111111ll1ll1ll111111111 J b No. 84056

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2/9/88 Revision 4 Page 5 not address the radiation release effects of the vent remaining open, Cygna requested verification that the release would be acceptable. TU Electric performed a calculation which verified that the release was within the limits of 10 CFR 100.

Cygna Observation MS4)6-01 was closed based on the results of TU Electric calculation TNE-CA-094, dated September 19, 1984; however, Cygna requested additional information in Reference 5 to assess the design change control aspects of this finding.

g The additional information requested in Reference 5 was a copy of i OEI-T183. TU Electric, in Reference 6, informed Cygna that OEI-T183 is the Open Engineering Item tracking number and that the design change was implemented on ICD-2323-MI-2229-02, Revision 5. Cygna has reviewed this documentation and finds it acceptable. In Reference 7, Cygna was told that the tank venting arrangement had changed to two rupture disks and an open vent line. This design is also described in Reference 6, Item 3. The design was again changed and Cygna was informed in Reference 8.

The design change process and the new dose calculations needed to be reviewed, since the tank will be continuously vented rather than having the vent line isolated by operator action.

Response- As part of the SWEC Design Basis Consolidation Program concerning the design requirements for the CCW Surge Tank (see Reyiew Issue No. 7), the need to isolate the surge tank on a high g

j radiation signal has been eliminated. The surge tank will be permanently vented through pipes routed to the floor drain system which goes to the liquid radwaste system. The room atmosphere i

is vented to the stack via radiation monitors (Reference 12) l Status: Closed.

Cygna reviewed SWEC Design Basis Document (DBD)-ME-027, and a radiological calculation with its supporting documentation (Reference 10). For heat exchanger tube ruptures where one side is reactor coolant, the NRC typically requires that offsite , doses be less than 10% of the 10 CFR 100 allowable doses. SWEC used this criteria to evaluate the doses that could result from a Reactor Coolant Pump Thermal Barrier Rupture. The radiological doses calculated by SWEC are only about 10% of the 10% of 10 CFR 100 allowable doses. Credit was taken for operator action. This is acceptable to Cygna. The dose analysis was conservative by assuming that all of the reactor coolant that leaked into the m Texas Utilities Electric Company

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2/9/88 Revision 4 Page 6 atmosphere. The analysis and assumptions are acceptable to Cygna. In addition, since the tank is normally vented, to A potential exposure of operators to radiological doses /_4_\

mmimize (the ALARA concept), a design change was being pursued to vent gases directly to the plant stack HVAC system, not directly into the room (Reference 12).

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3. Class 5 Pining

References:

L Cygna Phase 4 Final Report, TR-84056-01, Revision 0, Observation MS-02-01 (not yet issued).

2. N.H. Williams (Cygna) letter to J.B. George (TUGCO),

84056.010, dated July 30, 1984.

3. Lhi. Poppelwell (TUGCO) letter to N.H. Williams (Cygna),

dated August 11, 1984.

4. NJL Williams (Cygna) letter to J.B. George (TUGCO),

84056.023, dated August 21, 1984.

5. Communications Report between D. Wade (TUGCO) and R.

Hess (Cygna), dated September 5,1984, 3.00 p.m.

6. Lhi. Poppelwell (TUGCO) letter to N.H. Williams (Cygna),

dated September 11, 1984.

7. Lhi. Poppelwell (TUGCO) letter to N.H. Williams (Cygna),

dated September 21, 1984.

8. Lhi Poppelwell (TUGCO) letter to N.It Williams (Cygna),

dated September 25, 1984.

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9. . Communications Report between D. Wade (TUGCO) and R.

Hess (Cygna), dated September 26,1984,11:00 a.m. g

10. Communications Report between D. Wade, J. Van Amorongen (TUGCO) and R. Hess, N. Williams (Cygna) dated October 1, 1984, 2.00 p.m.  !

IL N.H. Williams (Cygna) letter to V. Noonan (USNRC),"Open Items Associated with Walsh/Doyle Allegations," 84042.022, dated January 18, 1985.

12. N.H. Williams (Cygna) letter 84056.060, dated hfarch 29, 1985.

to J.W. Beck (TUGCO),

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13. N.H. Williams (Cygna) letter to W.G. Counsil (TkJGCO),

84056.088, dated October 16, 1985.

14. W.G. Couasil (TUGCO) letter to RJ. Stuart (Cygna), dated September 2,1986.

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Transcript of meeting between TU Electric and Cygna at  !

15.

Glen Rose, Texas, on May 19, 1987.

16. Communication Reports from Cygna audit, July 15-17,1987, at SWEC, Boston office.

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17. Communication Reports from Cygna audit, August 17-21, '

l 1987, at SWEC, Boston office.

18. Communication Reports from Cygna audit October 19-23, .

1987 at SWEC, Boston office. l 1

l Summary: Per Gibbs & Hill, Class 5 piping is not seismically designed; it is only seismically supported to prevent it from falling on safety-related equipment. TU Electric did provide documentation showing that the specific Class 5 CCW piping in Cygna's review scope was ,

seismically analyzed and, therefore, would remain functional as- l required. d j Observation MS-02-01 was closed for the CCW system based on the documentation and analyses provided. In Reference 13, Cygna jd requested information regarding the criteria to determine whether a Class 5 piping system should be seismically analyzed.

Response- In Reference 14, TU Electric provided a response that delineated ,

the criteria to determine if Class 5 piping is seismically analyzed l

, and cited three procedures by which the determination is made. .-

1 In Reference 15, SWEC provided information indicating that a coniplete review of all uses of Class 5 piping would in conducted, determination of functionality would be made, and any fixes or  ;

modifications required to ensure functionality would be implemented.

Status: Closed.

In References 16 and 17, Cygna reviewed applicable SWEC

.- b procedures and methodology to determine which segments of Class 5 piping must remain functional during a seismic event and what effects a rupture of Class 5 piping in other safety systems would have on the ability of these systems to grform their safety function. Since the review of the CCW system is not yet complete, there were no Design Modification Packages for Cygna to review as of August,1987 which specifically addressed this issue.

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l 2/9/88 i Revision 4 Page 9 i Cygna re-visited this issue at the SWEC Boston office (Reference 18), seeking confirmation that the SWEC review of safety-related systems for Class 5/ Class 3 pressure boundary integrity and functionality, is following a formalized procedure, and is being implemented properly.

As reported in Reference 18, Cygna reviewed SWEC Procedure PP-204, Rev. 2, entitled "Drawing / Diagram Validation Procedure" and dated September 9,1987. Paragraph 63.2.4 requires that each ,

nuclear safety related system be reviewed to determine if failure I of the Class 5 or Class O piping would result in the loss of its A I safety function. The procedure adequately addressed 4 11 i drawing / diagram validation, and, in particular, the Class 5 piping l issue.

SWEC concerns regarding some of the Class 5/ Class 3 interfaces in the CCW and SSW systems, originally discussed in a SWEC internal memorandum, had been transferred to the drawing / diagram validation record forms, and are, or will be, resolved via the DVP process. Cygna reviewed some of these records for the SSW system which addressed the review of Class 5 piping adequately.

For example, the records on the SSW Discharge Structure ECE MI-0233-A, identified that it had not been designed or built as a seismic Category I structure. The action en this identification was the generation of DCA-5480 Rev.0.

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4. Fire Doors

References:

L N.H. Williams (Cygna) . letter to J.B. George (TUGCO),

84056.010, dated July 30, 1984.

2. 1E. Poppelwell (TUGCO) letter to N.H. Williams (Cygna),

dated August 11, 1984.

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3. N.H. Williams (Cygna) letter to J.B. George (TUGCO),  !

84056.023, dated August 21,1984. l

4. L.hi. Poppelwell (TUGCO) letter to N.H. Williams (Cygna),

dated August 31, 1984.

5. Communications Report between J. Van Amorongen (TUGCO) and R. Hess (Cygna), dated September 11, 1984, ILOO a.m.

Communications Report between hiark Wells (TUGCO) and R. I 6.

Hess (Cygna), dated September 13,1984,11.00 a.m.

7. Lhi. Poppelwell (TUGCO) letter to N.H. Williams (Cygna), )

dated September 17, 1984.

8. N.H. Williams (Cygna) letter to J.W. Beck (TUGCO) 84056.060, dated hiarch 29, 1985.
9. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO), l

. 84056.088, dated October 16, 1985. l

10. Transcript of meeting between TU Electric and Cygna at Glen Rose, Texas, on hiay 19, 1987. 1
11. Communication Reports from Cygna audit, July 15-17,1987, at l SWEC, Boston office.
12. Communication Reports from Cygna audit, August 17-21, 1987, ]

at SWEC, Boston office.

13. Communication Reports from Cygna audit, November 1114, 1987, at Comanche Peak site.

Summary: Cygna noted that the double doors between the train A & B nuclear chillers did not have a U.L fire rating label. TU Electric stated that they had previously noted this and that the proper door was being installed. TU Electric could not provide Texas Utilities Electric Company Comanche Peak Steam Electric Station L JL i Independent Assessment Program - All Phases tilllilillitilll!!Ililllililli J b No. 84056 TUE\23MS-ISSUE.04

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documentation of how the error was noted but did supply copies l of a purchase order for the correct door. Subsequent reinspection l l

by Cygna verified that the proper door had been installed. TU Electric stated that an NCR or other paper work was not i initiated, since the door is not safety-related. The door is required l to meet Fire Protection requirements. 4 I

In Reference 3, Cygna requested documentation that showed how the incorrectly labeled doors were discovered by TU Electric.  !

Cygna had not received the requested information.

was to provide assurance that This nonconforming g j 1

information '

non-safety related items which are installed to protect safety-related items are identified, documented, tracked and corrected.

I In Reference 9, Cygna requested the procedures regarding the documentation, tracking, and corrective action for discrepancies in

[d the hazards protection area.

Response: Cygna has received the requested procedures. TU Electric '

Administrative Guideline 23 appears to adequately address the tracking and close out of nonconformances provided that the i I

nonconformances are identified and documented. The procedure for identifying and documenting nonconformances is given in  ;

procedure CP-QP-16.0, Revision 19, and appears to apply only to )

the identification of nonconformances associated with  !

safety-related items.

In Reference 10, TU Electric provided information on the Fire I Protection Corrective Action Plan and the programs that have  ;

been developed to provide assurance that CPSES meets the fire protection requirements or justifies any deviation from them. d !

Impell and SWEC, the contractors responsible for the fire protection program, have procedures and documents regarding the identification of problems and the closcout of problems (Reference 13). Impell is responsible for the fire hazards review I while SWEC is responsible for the design of the barriers. l, As part of the Design Basis Consolidation Program and corrective actions, SWEC is reviewing the fire barrier requirements-dictated  ;

by Impell. The Fire Hazards Analysis drawings are integral to i DBD-M-001. SWEC calculation 16345-CS(S)-227 is a review and qualification of structuralinterior construction elements identified on the Fire Hazards Analysis drawings for Unit 1 and common areas. Through the design change authorization process and Texas Utilities Electric Company M"4ElllE Comanche Peak Steam Electric Station

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2/9/88 Revision 4 Page 12 deficiency reports, the engineering / construction drawings are being revised to be in agreement with the fire barrier requirements.

Two deficiency reports (DRC-87-4214 and DRC-87-501-X), were written identifying that there were not appropriate quality assurance requirements imposed to meet FSAR Section 9.516.1 (Reference 13).

Status: Open.

Cygna needs to review revisions to the fire protection QA program to ensure that appropriate attributes of an effective fire barrier are inspected after the item is installed.

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5. Sincie Failure - Reactor Coolant Pumo Thermal Barrier

References:

1. Cygna Phase 4 Final Report, TR-84056-01, Revision 0, Observation MS-02-02 (not yet issued)L
2. Cygna Phase 4 Final Report, TR-84056-01, Revision 0, Potential Finding PFR-01 (not yet issued).
3. N.H. Williams (Cygna) letter to J.B. George (TUGCO),

84056.010, dated July 30, 1984.

4. Communications Report between D. Wade (TUGCO) and R.

Hess (Cygna), dated August 17,1984, 8:30 a.m.

5. 121. Poppelwell (TUGCO) letter to N.H. Williaras (Cygna),

dated August 24, 1984. l l

6. Communications Report between D. Wade (TUGCO) and N.

Williams (Cygna), dated August 30,1984, 3:30 p.m.

7. Communications Report between D. Wade (TUGCO) and R. l Hess (Cygna), dated September 5,1984, 3.00 p.m.
8. D.H. Wade (TUGCO) letter to N.H. Williams (Cygna),,

CPP A-40961, dated September 18, 1984.

9. Communications Report between D. Wade, J. Van Amorongyn A )

Q4

' (TUGCO) and R. Hess and N. Williams (Cygna) dated October

' 1,19o4, 2.00 p.m. ,

10. D.H. Wade (TUGCO) letter to N.H. Williams (Cygna),\

CPPA 41237, dated October 3,1984.

11. N.l t Williams (Cygna) letter to S. Burwell (USNRG), j 84056.032, dated October 9,1984. ,
12. Communications Report between D. Wade (TUGCO) and N. l Williams (Cygna), dated October 11,1984, 5:00 p.m.
13. N.H. Williams (Cygna) letter to S. Burwell (USNRC),

84056.035, dated October 22, 1984.

14. E.P. Rahe, Jr., (Westinghouse) letter to R.C. DeYoung (USNRC), NS-EPR-2938, dated July 13, 1984.

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15. T.R. Pu: year (Westinghouse) letter to J.T. Merritt, Jr.

(TUGCO) WPT-7436, dated July 23, 1984.

16. N.H. Williams (Cygna) letter to J.W. Beck (TUGCO) 84056.060, dated March 29, !985.
17. Communications Report between J. Marshall, J. Redding (TUGCO) and N. Williams, R. Hess (Cygna), dated May 10, 1985, 3:30 p.m.
18. N.H. Willizms (Cygna) letter to W.G. Counsil (TUGCO),

84056.088, dated October 16, 1985.

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19. W.G. Counsil (TUGCO) letter to RJ. Stuart (Cygna), dated a September 2,1986.
20. Transcript of meeting between TU Electric and Cygna at Glen Rose, Texas on May 19, 1967.

2L Communication Reports from Cygna audit, July 15-17,1987, et SWEC, Boston office.

22. W. G. Counsil (TU Electric) letter to NRC, TXX-6608, dated July 29,1987.
23. Communication Reports from Cygna audit August 17-21, 1987 at SWEC, Boston office.

( 24. -

Communication Reports from Cygna audit October 19-23, 1987 at SWEC, Boston office.

25. Communication Reports from Cygna audit December 7-11, 1987 at SWEC, Boston office.

Summary: Cygna expressed a concern that if the single temperature controlled isolation valve on the outlet of the reactor coolant pump thermal barrier should fail to close subsequent to a rupture of the thermal barrier, then low pressure portions of the CCW system would be over pressurized, and reacter coolant could be released outside containment. Westinghouse also notified the NRC and TU Electric of a similar problem with CCW systems they designed. TU Electric informed Cygna that they were filing a 50.55(e) report with the NRC on this issue and that they would investigate the generic implications of this finding. Cygna Texas Utilities Electric Company Comarche Peak Steam Electric Station 3, , IndepcM.ent Assessment Program - All Phases J

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2/9/88 Revirion 4 Page 15 submitted two letters on this subject to the NRC and TU Electric in accordance with our review procedures for a Definite Potential Finding. [

Observation MS-0202 was upgraded to Potential Finding PFR-01.

Subsequently, accordance w References 13 and 14 were sent to the NRC in ith Cygna's procedures for processing a Definite lh Potential Finding. Reference 16, Attachment E, item 1.1 specifically asks for demonstration that single failure criteria for valves has been satisfied. TU Electric was requested to provice Cygna with the 50.55(e) report addressing the design problems of this system.

Response: TU Electric responded to this item in Reference 19, by. stating that Cygna's sing'.e failure concern was based upon a misinterpretation of the CCW system design and that two safety-related isolation valves are provided downstream of the control grade valve, to isolate a thermal barrier rupture, thereby satisfying the single failure criteria. This position was subsequently changed by information provided to Cygna in Reference 20, wherein TU Electric stated that redundant '

instrumentation and thermal control valves would be installed to detect and isolate a thermal barrier rupture. TU Electric has identified this issue as a poten'lally reportable item under the provisions of 10 CFR 50.55(e) (Reference 23). /A Status: Closek -

Cygna reviewed the acceptability and implementation of the new design discussed in Reference 20. Cygna reviewed documents provided by SWEC, and SWEC addressed subsequent questions as -

detailed in References 21, 23, 24 and 25. Cygna noted that a SWEC calculation had demonstrated the pressure adequacy of flanges per ANSI B16.5,1968.

1 An additional concern was raised in References 21 and 23 ,

I regarding the design adequacy of orifices used in the upstream (of isolation valves) portions of the thermal barrier lines which would l be subjected to 2500 PSIG. (nominal) and high flows following a j thermal barrier rupture. In Reference 23, STEC provided

% formation that at least one orifice design inadequacy had been 4 und, and that results of SWEC Calculation No.16345-ME(8)494, i.evision 1 would be used to initiate a Design Modification to pgrade the orifice to withstand the calculated pressures and r .ows.

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6. hiissing Valve Sizing Calculations

Reference:

1. Telecopy from N.R Williams (Cygna) to R.E. Ballard (G&H) dated hiay 9,1985.
2. Transcript of CPRT/Cygna meeting dated hiay 21, 1985 (NRC/I & E hiecting).
3. Communications Report between D. Ghosh (G&H) and L hfaggio/ICZee (Cygna) dated June 28, 1985.
4. N.H. Williams (Cygna) letter to J.W. Beck (TUGCO),

84056.078, dated August 1,1985.

5. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),

84056.088, dated October 16, 1985.

6. W.G. Counsil letter te RJ. Stuart (TUGCO) dated September 2, 1986.
7. Transcript of meeting between TU Electric and Cygna at Glen Rose, Texas on April 21, 1987.
8. Transcript of meeting between TU Electric and Cygna at Glen Rose, Texas, on hiay 19,198'/.

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9. ' Coaimunication Reports from Cygna audit, July 15-17,1987, at SWEC, Boston office.
10. Communication Reports from Cygna audit, August 17 21, 1987, at SWEC, Boston office.

Summary: Cygna requested equipment and valve sizing calculations,. along with pressure drop and flow calculations for the CCW system, at the beginning of the review. Sizing calculations for the. CCW surge tank relief valve, vent valve, and vacuum breaker were not provided b; Gibbs & Hill. Cygna perfr med an assessment of the ,

adequacy of these components based on normal system operation (

and accepted the design based on Cygna's calculations. i Subscquent evaluation of various scenarios, such as in-leakage to the system, caused Cygna to again request the sizing calculations i and/or design bases from Gibbs & Hill. l Subsequent design changes, involving the removal of subject valves, made the question of valve sizing moot. The new design h

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2/9/88 Revision 4 Page 17 was to incorporate two rupture disks to provide relief capacity, while the vent line would remain open to atmosphere. Cygna was still concerned about surge tank sizing and design specifications for the rupture disks.

Response: In Reference 8, it was learned that the aforementioned rupture disks had been removed from the design. SWEC responded that Cygna's questions on vent line sizing were addressed in their response to Review Issue No. 7. Tnis response identified SWEC Calculation No.16345 ME(B)-130 concerning the prevention of tank overpressurization by open vent lines. SWEC stated that the vent line sizing would accommodate maximum in-and out-flows. Also, A SWEC stated that sufficient vent area is being added to the tank, Q4 and Referenced DM-84-197. In Reference 7, SWEC stated that pertinent calculations and design bases, relevr.nt to vent line sizing, will be incorporated into the consolidr ed Design Basis Document (part of Design Validation Package, DVP)

Status: Closed.

The permanently open vent system that has been incorporated as part of the design validation program for the CCW surge tank makes this issue moot. The cdequacy of the open vent system design was reviewed in association with Review Issue No. 7. .

Cygna considers the absence of Gibbs & Hill sizing calculations to be a moot point in view of subsequent reviews and redesign.

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7. CCW Surce Tank Sizine and Desien Basis  !

References:

1. Gibbs & Hill Calculation 229-12, Revision 1, "CCW Surge Tank," dated January 4,1979.
2. Transcript of CPRT/Cygna meeting, dated May 21, 1985 (NRUI&E Meeting).
3. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),

84056.088, dated October 16, 1985.

4. W.G. Council (TUGCO) letter to RJ. Stuurt (Cygna), dated September 2,1986.
5. Transcript of meetig between TU Electric and Cygna at Glen Rose, Texas on April 21, 1987.
6. Transcript of meeting between TU Electric and Cygna at Glen Rose, Texas on May 19, 1987.
7. Communication Reports from Cygna audit, July 15-17,1987, at SWEC, Boston office.
8. Communication Reports from Cygna audit, August 17-21, 1,987, at SWEC, Boston office. ,

Summary: The referenced Gibbs & Hill calculation does not address in-leakage to the CCW system caused by failures in systems cooled by *the CCW system. This calculation also does not address or justify the surge tank design pressure of 10 psig versus the higher design pressure of 150 psig of the CCW pipmg and components.

Cygna raised these issues m relation to the failure of the reactor  ;

coolant pump thermal barrier, but they also apply to postulated i failures of other heat exchanger tubes or leakage froci other l components served by the CCW system which aperate at, higher pressure than the CWW system. Smce the surge tank i common to both safeguards loops of the CCW system, its integrity is critical '.o the system meeting its safety function.

This iosue of in-leakage is coupled viith the resolution of-Review Issue No. 5. In Reference 3, Cygna requerv d the design basis for sizing the surge tank and for the design pressem j i

In Reference 4, 7 U Electric provided a response to Cygna's l request for the cud surge :ari sizing design basis. Subsequent _k l

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2/9/88 Revision 4 Page 19 to this response, in Reference 5, TU Electric described the Design Basis Consolidation Program and the development of a Design Basis Document (DBD hie-0229) for the CCW system. At the time of this meeting, the CCW Design Basis Document was in draft form.

In Reference 6, TU Electric provided additional information I regarding the surge tank sizing and pressure design basis.

The information provided in Reference 4 and at the meetings (References 5 and 6) did not address how the design of the CCW surge tank accommodates the effects associated with a tube rupture in any high temperature or high pressure heat exchanger, such as the excess letdown heat exchanger, the letdown heat exchanger, the RHR heat exchanger or the reactcr coolant pump thermal barrier. The design of the tank must consider this event or provide justification for not considering it.

Response: SWEC provided DBD-hie-0229, Revision 1A, Section 43.1.1 "CCW Surge Tank," which describes the design bases for the surge tank (Reference 7 The design bases and SWEC's responses (References 7 )and 8) are summarized below;

a. Allow for thermal expansion and contraction of the system.

4 SWEC provided calculations which address loss of water due ,

to normal leakage, other leaks and cracks and thermal expansion. Since preliminary information was used in these calcuhtions, the volume adequacy will be confirmed by SWEC

. (Reference 8)

b. Insure that the CCW pumps have sufficient NPSH.

SWEC has reviewed and accepted, with justifications, a previous Gibbs and Hill calculation. There is adequate margin to meet the required NPSH. (Reference 8.)

c. Provide a means to prevent system overpressure due to in leakage from reactor coolant system.

SWEC has completed Calculation No. 16345-hig(B).130, showing that the design pressure will not be exceeded.

d. Provide for supply of makeup water from Demineralized Water System or the Reactor hiakeup Water System.

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T 2/9/88 Revision 4 Page 20 SWEC has revise.1 the CCW System Flow Diagram which shows makeup water from both of these systems. One of these systems is seismic Category I, so the SRP 9.2.2 guideline is met (Reference 8).

As a fallout from the SWEC design validation effort, the level set A points on the surge tank need to be modified. Cygna reviewed /_4\

documentation related to this modification process and finds it acceptable (Reference 8).

Status: Closed.

The information and dacumentation, described above and in References 7 and 8, adequately addresses the surge tank design bases and how these are met.

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8. CCW Pumo Motor Sizing

References:

L Gibbs & Hill CCW Pump Specification 2323-MS-11, Revision 2, dated December 10, 1974.

2. Gibbs & Hill Electric Motors Specification 2323-ES 1D, Revision 4, dated November 10, 1976.
3. Communications Report, dated August 1,1985, between J.

Oszewski/R. Hess (Cygna) and J. Irons (G&H).

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4. N.H. Williams (Cygna) letter to J. Redding (TUGCO),

84056.081, dated August 13, 1985.

5. N.H. Williams (Cygna) letter to W.G. Counsit (TUGCO),

84056.090, dated October 16, 1985.

6. W.G. Council (TUGCO) letter to R.J. Stuart (Cygna) dated September 2,1986.
7. Communication Reports from Cygna audit, July 15-17,1987, at SWEC, Boston office. g
8. Communication Reports from Cygna audit, August 17-21, 1987, at SWEC, Boston office.

Summary: The ' pump motor data supplied to the motor vendor in 1 Specif,ication 2323-ES-1D listed the motor horsepower as 1000 hp l and provided a torque-speed curve for the pump with the  !

discharge valve closed. The pump is actually started with the l discharge valve open for most modes of operation. The valve l open condition is normally a more limiting design condition for l pump motor current draw and accelerating time. Therefore, Cygna l was concerned that the pump motor may not have been sized j correctly for all service condition.4. ,

Response: The CPRT response, as included in Reference 6, is that the motor acceleration time at 80% 280V) of rated voltage (6600V) is less than 23 seconds, well wit in the 5 second requirement specified.

g The motor torque at 80% of rated voltage is 6161 ft-lbs and the load torque is 43813 ft lbs at 1176 RPM. This Reference indicates that the CCW pump motor was sized, and the acceleration time determined, based upon an open discharge valve.

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Status: Closed.

While the CCW pump motor concerns were adequately addressed, l similar motor sizing concerns have arisen on the containment spray pump motors and are addressed in Electrical Review Issue g

No. 7. (References 7 and 8.)

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9. CCW Suge Tank Vent / Relief Single Failure L Transcript of TUGCO and Cygna meeting, dated May 21, 1985 j

References:

and May 22,1985 (NRC/I&E Meeting).

2. Cygna Phase 4 Final Report, TR-84056-01, Revision 0, Observation MS-02-01 (not yet issued), Mechanical Systems Review Issues List, Review Issue 3.
3. Cygna Phase 4 Final Report, TR-84056-01, Revision 0, Observation MS-0202 (not yet issued), Mechanical Systems Review Issues List, Review Issue 5.
4. N.H. Williams (Cygna) letter 84056.060. dated March 29, 1985.

to J.W. Beck (TUGCO), g

5. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),

84056.083, dated October 16, 1985.

6. W.G. Counsil (TUGCO) letter to RJ. Stuart (Cygna), dated September 2,1986.
7. Transcript of meeting between TU Electric and Cygna at Glen Rose, Texas on April 21, 1987. g
8. Communication Reports from Cygna audit July 15-17,1987 at

. SWEC, Boston office.

9.- ' Communication Reports from Cygna audit August 17 21, 1987 i at SWEC, Boston office.

Summary: During the technical review, Cygna assessed the capability of the .

surge tank vent-relief / vacuum breaker combination to meet single I failure criteria. 'Ihis assessment was based on the relief valve and f vacuum breaker being passive devices with no external operators.

Subsequent discussions with the project Senic,r Review Team and j the NRC led to a re-evaluation of this assessment. These components should now be considered active components, since~

mechanical movement is required for their proper operation.

Since both the power supply and position indication for the vent valve are not safety-related, it cannot be relied upon as a backup for the relief valve and vacuum breaker under accident conditions.

Based on this re< valuation, the vent and relief capability of the l CCW surge tank was not considered to meet the sins;1e failure critcria, d Texas Utilities Electric Company 1 Comanche Peak Steam Electric Station >

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2/9/88 Revision 4 Page 24 Reference 6 provided TU Electric's response to the Cygna concern regarding single failure criteria as related to the CCW surge tank relief valve, vent valve and vacuum breaker. This particular concern raised by ,Cygna is now moot since the design of the CCW surge tank ventmg and relief arrangement has changed as discussed in Reviev< Issue Nos. 2 and 7.

Status: Closed.

The ability of the CCW surge tank to meet the single failure l criteria was reviewed as part of Review Issue No. 7. l l

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10. RHR Heat Exchancer Discharce Valve Setooint References 1. Communications Report between B. Hess (Cygna) and J. Irons (Gibbs and Hill), dated June 20,1985 at 11:30 a.m.

I 2. Communications Report between J. Oszewski (Cygna) and J.

Irons (Gibbs and Hill), dated June 27, 1985.

3. Communications Report between J. Oszewski (Cygna) and J.

Irons (Gibbs and Hill), dated June 28, 1985, afternoon conference.

4. Communications Report between L Maggio, K. Zee (Cygna) and D. Ghosh (Gibbs and Hill), dated June 28, 1985, morning conference.

, 5. Communications Report between B. Hess, J. Oszewski l (Cygna) and J. Irons (Gibbs and Hilll dated August 1,1985.

f 6. N. IL Williams (Cygna) letter to J.W Beck (TUGCO),

84056.078, dated August 1,1985.

7. N. It Williams (Cygna) letter to W.G. Counsil (TUGCO),

84056.088, dated October 16, 1985. [

8. W. G. Counsil (TUGCO) letter to R. J. Stuart (Cygna), dated
  • September 2,1986. l
9. Transcript of meeting between TU Electric and Cygna et Glen Rose, Texas on April 21, 1987. ]
10. Communication Reports from Cygna audit, July 15-17,1987, at l SWEC, Boston office.

IL Communication Reports from Cygna audit, August 17 2.1, 1987, at SWEC, Boston office.

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12. Communication Reports from Cygna audit October 19-23, 1987 at SWEC, Boston office.
13. Communication Reports from Cygna audit December 711, l 1987 at SWEC, Boston office.

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2/9/88 Revision 4 Page 26 Summary: Cygna hiechanical Systems Checklist hts-06, Item 8b, determined that the CPSES satisfactorily met the BOP-FR-1 requirement that valves associated with the residual heat removal (RHR) cooling open simultaneously with Containment Pump isolation valves. The CCW System RHR Heat Exchanger discharge valves are motor-operated butterfly valves. Cygna was interested in the design basis used to determine the "partially" open position upon receipt of an T signal. In References 1, 2, 4 and 6, Cygna requested a copy of the setpoint calculation and/or any associated input criteria from Gibbs and Hill.

Response: The design basis for the partial open position of the CCW valve on the outlet of the RHR heat exchanger on receipt of an *S" signal, is a system require,nat that some flow through the heat exchanger be provided during "S" signal mode to compensate for the normal flow paths in the non-safeguards loop which are isolated by an "S" signal (e.g. ventilation chillers). The limitation on the maximum opening is to minimize pump runout during that mode.

During the August 17-21, 1987 review (Reference 11), SWEC l' provided Cygna with their setpoint calculation 16345-hie-(B)173.

Cygna concerns included the flow rates for single tram A ,

operation during "S" signal in the event of failure of the train B CCW pump. Also, during two train operation "S" signal mode, both trains A and B are still cross-connected, and with both CCW pumps running, one half of the flow through the non-safeguards  ;

loop would be supplied by each train. It was not clear that these  !

conditions had been analyzed consistently in the calculation, and i the scenario considered did not tabulate flows correctly. SWEC 1 responded that the calculation would be revised. l l

During the October 1987 review (Reference 12), SWEC stated that l I

this valve position would be analyzed as part of their overall CCW system flow balance calculation, and that calculation 16345-hie (BF173 would be retained only for its analfsis of cavitation / flashing potential in this type of valve.

Status: Closed.

During the December,1987 review, (Reference 13), Cygna reviewed a new SWEC calculation which analyzed the effects of the RHR l system and the Spent Fuel Pool (SFP) system operation on the CCW pump performance. His calculation, in conjunction with the overall CCW flow balance calculation (see RIL No. 1),

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2/9/88 Revision 4 Page 27 adequately analyzed the RHR bcat exchanger discharge valve position as it relates to flow allowances which maintain the functional integrity of the CCW heat removal system. Adequate system alignments corresponding to relevant operating modes had been considered postulating single failure and valve degradation scenarios. Appropriate conservative assumptions had been applied. A As part of the flow analysis discussed in RIL No.1, various computer runs were made assuming the valve position was between 36 and 44 percent open. These departures from the 40 percent value did not detrimentally affect the flow requirements of the overall system.

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