ML20217K212
| ML20217K212 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 10/17/1997 |
| From: | Muench R WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20217K215 | List: |
| References | |
| ET-97-0126, ET-97-126, NUDOCS 9710240063 | |
| Download: ML20217K212 (13) | |
Text
.. ___
I 6
Rchard A. Muench WQLF CREEK NUCLEAR OPERATING CORPORATIOrJ Vce President Engineering October 17, 1997 ET 97-0126 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station F1-137 Washington, D. C. 20555
Reference:
Letter ET 97-0050, dated May 15, 1997, from R. A. Muench,.
WCNOC to NRC
Subject:
Docket No. 50-482: Application for Exigent Amendment to Technical Specification 3/4.5.2, Emergency Core Cooling System Venting Gentlemen:
This letter transmits an application for amendment to Facility Operating License No. NPF 42 for Wolf Creek Generating Station (WCGS). Wolf Creek Nuclear Operating Corporation (WCNOC) proposes to revise Technical Specification Surveillance Requirement 4.5.2b and associated Bases as they relate to the requirement to vent the Emergency Core Cooling System (ECCS) pump casings.
WCNOC requests that this proposed license amendment request be processed under the exigent situation provisions of 10 CFR 50. 91 (a) (6) . WCGS shut down on October 4, 1997 for a refueling outage and is currently in MODE 6. This exigent situation occurred when it was identified on October 14, 1997, after discussions with another utility and further reviews, that WCGS would not be in literal compliance with the wording of Surveillance Requirement 4.5.2b.1).
The surveillance requirement states that the ECCS subsystem is demonstrated OPERABLE once per 31 days by "1) Verifying that the ECCS piping is full of water by venting the ECCS pump casings and accessible discharge piping high 6
points." Upon review, it was identified that the Centrifugal Charging pump casing did not have an installed casing vent. Instead of the installed casing vent, the suction and discharge piping are installed as vertical runs of piping attached to the top of the pump. Information provided by the pump manufacturer has verified that the vertical configuration of the piping is sufficient to prevent the accumulation of noncondensible gases and as such the system has remained OPERABLE and able to perform its safety function.
However, to be in literal compliance with the _ specifications, WCNOC is requesting this amendment to remove the reference to the Centrifugal Charging pump casing vent. Since this issue was identified on October 14, 1997 and the expected date for entry into MODE 4 is November 4, 1997, WCNOC requests this e amendment be handled on an exigent basis.
A Safety Evaluation is provided in Attachment I; a No Significant Hazards Consideration Determination, in Attachment II. Attachment III is the related J Environmental Impact Determination. Marked up pages are provided in Attachment IV (for current Technical Specifications and Bases) and in Attachment V (for Improved Technical Specification Bases submitted by th (
q Reference). h) 9710240063 971017 PDR ADOCK 05000482 P PDR P.O. Box 411/ Burtington, KS 66839 / Phone- (316) 364-8831 llllllllll[lllllllllhll{
- * * ' 3 ' -
An Equal Opportunity Employe, M F HC VET
- ___--a
ET 97-0126 Page 2 of 2 Ip accar, dance with 10 CFR 50.91, a copy of this application, with attachments, is' being provided to the designated Kansas State Official. This proposed revision to the WCGS T3chnical Specifications will be made effective upon i issuance of the amendment.
l l If you have any questions concerning this ratter, please contact me at (316) l 364-8831, extension 4034, or Mr. Richard D. Flannigan, at extension 4500.
Very truly yours, Rich rd A. Muench RAM /jad Attachments: I -
Safety Evaluation II - No Significant Hazards Consideration Determination III - Environmental Impact Determination IV -
Proposed Current Technical Specification Change V - Proposed Improved Technical Specification Change cc: V. L. Cooper (KDHE), w/a W. D. Johnson (NRC), w/a E. W. Merschoff (NRC), w/a J. F. Ringwald (NRC), w/a K. M. Tbsmas (NRC), w/a 1
(..
- l l.*
4 s.
k s ,
4 STATE OF KANSAS '
)'
. )- ss COUNTY OF COFFEY )'
Richard'A.[Muench,~of lawful age,-being first duly sworn upon oath says that he is Vice. President Engineering of Wolf Creek Nuclear Operating corporation;-
that he has ' read the foregoing document and knows the . content thereof; -that he has- executed that same for and on behalf . of-. said Corporation with full power.and authority:to do so; and that the facts therein stated are true and
. correct to the best of his knowledge, information and belief.
By Richardf.Muench.
Vice President Engineering
' SUBSCRIBED and' sworn to before me this /N3 . day of det , , 1997.
r
~
vila bl e $i Notary h blic
- ANGELA E.WESSEL g Notary PubEc. State of Kansas A Appt. Empires 67/c5/9 9 ,
Expiration Date:
- E /d d, /999 r
Attachm0nt I to ET 97-0126 Page 1 of 4 e
ATTACHMENT I SAFETY EVALUATION 4
l' I
L ;--
Attachmtnt'I to:ET 97-0126 Page 2 of,4
+'
~
. Safety Evaluation-ProposedChanges,f Thisilicense- amendment: request proposes to revise Wolf _ Creek Generating Station - (WCGS) Technical Specification - Surveillance Requirement 4.5.2b and1
-associated. Bases'as.they relate'to the requirement?to vent the Emergency Core Cooling System-(ECCS) pump casings. Surveillance _ Requirement 4.5.2b.1) would be revised-to state: ,
4 "l) _ Verifying that-the ECCS piping is full of water by venting the
__RHR-and SI pump casings and_: accessiblo ECCS '. discharge- piping - high points,.and..."
The proposed change to vent only the_ Residual Heat Removal (RHR) and Safety Injection'(SI)-pump casings ~is-necessary since the Centrifugal Charging pumps
+
- are not _ provided with ; a vent ' connection (or line) because they -have top '
- mounted - suction : and discharge- - nozzles ande noncondensable: gases o can - escape -
through the' nozzles.. This change - will better align the venting requirements with the. installed-piping and vent. valve configuration.
Backuround
. Technical l Specification Surveillance Requirement 4.5.2b.1) requires verifying
_ : that : the ECCS piping --is- full of water by -venting the ECCS - pump. casing . and
~
~ accessible : discharge piping -: high points at - least once per 31 days.- The Technical _ Specification Bases states _ that this _ surveillance' requirement ensures against inoperable pumps. caused by gas binding or water hammer in ECCS-piping.
The:ECCS is-designed-to-supply-core cooling and negative reacticity to ensure the reactor is cooled and shutdown following a postulated accident. .The ECCS
< pumps - include the -: high 1 head safety injection - pumps (Centrifugal- Charging
, pumps), ;the intermediate head safety injection pumps _ (SI pumps), and the low
- head': safety injection pumps -- (RHR pumps) . The SI pumps and RHR pumpsLdesigns-
- include?i nstalled. pump casing vents.- The: Centrifugal Charging pumps are an 11
= stage,n multi-diffuser 4 type pump manufactured by Pacific Pumps- with no
- installed pump casing ; vent. . g The design of the' pump does ' not Linclude casing
~
vents,1 ; since the - pump - hasi top: mounted suction and discharge nozzles which
. allow noncondensable gases in the pump to escape through the nozzles.-
On.- October-^14, 1997 after discussions with - another utility and- further
- reviews, _WCNOC personnel determined that WCGS would not be in -'. iteral
- compliance with the wording - of Surveillance Requirement-- 4.5.2b.1) . A review
,'of j procedure 'STS BG-002, "ECCS Valve Check and System Vent," determined that
- the Centrifugal Charging pump casings were not being vented as required by-the surveillance requirement. 1 Additionally,- WCNOC personnel determined that the surveillance -procedure- was deficient in providingE the appropriate discharge piping,high points. This issue 'will' be the subject of a subsequent Licensee
= Event Report. WCNOC had. considered ourselves in: compliance with the requirement toivent the ECCS pump casings since the Centrifugal Charging pumps are : not provided- with : a vent connection (or line) because they have ~ top-mounted. suction and ' discharge nozzles and noncondensible gases can escape through the nozzles.
. Evaluation The.ECCS pumps are normally in-a standby, non-operating mode.
- As such, flow path piping has the potential =to devel y voids and pockets of entrained gases.
Maintaining the piping fromithe ECCS pumps to the reactor coolant system full 1
Attachment I to ET 97-0126 Page 3 of 4 of watpr by venting pump casings and accessible discharge piping high point vents ensures that the system will perform properly, injecting its full capacity into the RCS upon demand. Venting of the non-operating subsystems ensures that the piping is full of water and provides confidence that a potential water hammer. event which could result from voiding would not result in unacceptable dynamic loads.
The Centrifugal Charging pumps are designed and installed to be self-venting, and are not provided with casing vent valves. The design of the pump p. aces the suction and discharge piping at the top of the pump casing. The Centrifugal Charging pump suction piping is in communication with either the Refueling Water Storage Tank or the Volume Control Tank. Both of these sources provide a net positive suction pressure for the pumps. The design of the Centrifugal Charging pumps is such that significant noncondensible gases do not collect in the pumps, whether they are running or not. The suction and discharge lines are on the top of the pumps and the internal cavities in the pump that do not communicate with the nozzles are small enough that significant gas accumulation in the pump casings will not occur.
Noncondensible gases that may collect in the discharge piping will be vented at the discharging piping high points every 31 days per Surveil'ance Requirement 4.5.2b.1).
Operating experience has shown that no significant voiding has occurred in the affected piping which will continue to be vented at a high point every 31 days per Surveillance Requirement 4.5.2b.1). Discussions with the pump vendor has indicated that small amounts of gases can be swept through the pump without causing damage to the pump. WCGS has had the pumps disassembled and inspected by the vendor. Only normal signs of marking and wear were observed on the pump impeller.
The change proposed in this request will provide continued confidence that unacceptable accumulations of gases will not occur, and will align the surveillance requirements with the design configuration of the ECCS piping.
Schedule Requirements WCNOC requests that the proposed change be approved on an exigent basis.
Approval of this umendment is necessary to support startup from the current refueling outage. WCGS shutdown on October 4, 1997 for a refueling outage and is currently in MODE 6. Technical Specification LCO 3.5.3 requires one OPERABLE Centrifugal Charging pump in MODE 4. Surveillance Requirement 4.5.3.2 requires the Centrifugal Charging pump be demonstrated OPERABLE per the requirements of Specification 4.5.2. Therefore, it is necessary to have the requested change in place to satisfy the surveillance requirement, of 4.5.3.1 prior to entry into MODE 4. The refueling outage schedule shows entry into MODE 4 occurring on November 4, 1997. As provided in 10 CFR 50.91, an exigent situation exists when the licensee and Commission must act quickly and time does not permit the Commission to publish a Federal Register notice allowing 30 days for prior public comment. The circumstances could not have been foreseen and timely application made because WCGS considered ourselves in compliance with the requirement by crediting the design that any gas accumulation would be vented through the discharge piping of the pump as meeting the requirement to vent the pump casing. It was identified on October 14, 1997 that this position with respect to meeting the surveillance requirement was not in literal compliance with the Technical Specification wording. As such, the opportunity to make timely application did not exist.
WCNOC requests that these changes be made effective upon issuance to support the WCNOC schedule for entry into MODE 4.
Attachment I to ET 97-0126 Page 4 of 4
- Conclusion
- Ba' sed on the above discussions and the No Significant lia rards Consideration Determination presented in Attachment II, the proposed changes do not increase the orebability of occurrence or -the consequences of an accident or malfunction of equipment Artportant to safety previously evaluated in the Updated Safety Analysic Report; or create a possibility for an accident or malfunction of a different type than any previously evaluated in the safety analyses reports or reduce the margin of safety as defined in the basis for any technical specification. Therefore, the proposed changes do not adversely affect.or-endanger the health or safety of the general public or involve a significant safety hazard.
I
_ q .
Attechm2nt 11 to ET 97-0126 Pa9m 1 of 3 4
ATTACID4ENT II NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION
-Attachment II to ET 97-0126
-Page 2 of 3
, No Significant Hasards Consideration Determination Proposed Changes This license - amendment- request proposes to revise Wolf Creek Generating Station (WCGS) Technical Specification Surveillance Requirement 4.5.2b and associated Bases as they relate to the requirement to vent the Emergency Core
-Cooling System (ECCS) pump casings. Surveillance Requirement 4.5.2b.1) would
-be rovised to state "1) - Verifying that the_ECCS piping is full of water by venting the RHR and SI pump casings and accessible ECCS discharge piping high points, and..."
The proposed change to vent only the Residual Heat Removal (RHR) and Safety Injection (SI) pump casings is necessary since the Centrifugal Charging pumps are not provided with a vent connection (or line) because they have top-mounted suction and discharge nozzles and noncondensable gases can escape through the nozzles. This change will better align the venting requirements with the installed-pip!ng and vent valve configuration.
Application of Standards The following Standards identifiwd in 10 CFR 50.92 have beea used to determine whether the proposed changes involve a Significant Hazards Consideration.
Each of the identified proposed changes is evaluated against the three Standards.
Standard I - Involve a Significant Increase in the ProbaMlity or Consequences of an Accident Previously Evaluated The. proposed chan9.- will- elign the surveillance requirements with the installed system design and normal operating conditions. The conduct of surveillances required by Technical Specifications is not postm 4ted to initiate an accident. The intent of the surveillance ensures OPERABILITY - of the Centrifugal Charging pumps by verifying that the ECCS piping is full of water.and not subjected to gas binding or water hammer. The design of the Centrifugal Charging pumps is such that significant noncondensible gases do not collect in the pumps, whether:they are running or not. Therefore, it is
!unne.:essary to require periodic pump casing venting to ensure the equipment
'will remain OPERABLE. In addition, operating experience has-shown that no significant voiding has occurred in the affected piping which will continue to be. vented at fa' high point every 31 days per Surveillance Requirement 4.5.2b.1). Therefore, no increase in the probability or consequences of an accident will occur as a result of this change.
Standard II - Create the Possibility of a New or Different Kind of Accide.at fl from any Previously Evaluated The proposed change will not result in new failure modes because no new equipment - is installed and installed equipment is not operated in a new or different manner. The design of the Centrifugal- Charging pumps is such that significant noncondensible gases do not collect in the pumps, whether they are running or not. .Therefore, it is unnecessary to require periodic pump casing venting to ensure the equipment will remain OPERABLE. Manual venting operations have been performed which minimizes - the potential for voids i.1 syrtem piping. Accordingly, this change will not create the possibility of a new or different kind of accident.
-.m MNr .M
Attachment II to ET 97-0126 Page 3 of 3 Standard III - Involve a Significant Reduction in the Margin of Safety Th'e margin of safety is not significantly reduced because the proposed change provides assurance that locations where noncondensible gases can collect will be vented. Eliminating the requirement to vent the Centrifugal Charging pump casings where gases cannot collect has no functional effect on the system.
This assures proper system functioning. Additionally, operating experience has shown that no significant voiding has occurred in the affected piping which will continue to be vented at a high point every 31 days per Surveillance Requirement 4.5.2b.1). Therefore, this change will not involve a significant reduction in the margin ci safety.
Conclusions Based- on the above discussions, it has been determined that the requested technical specification revisions do not involve a significant increase in the probability of consequences of an accident or other adverse conditions over previous evaluations; or create the possibility of a new or differant kind of accident or condition over previous evaluations; or involve a significant reduction in a margin of safety. Therefore, the requested license amendment does nut involve a significant hazards consideration.
I 1
Attechm2nt III to ET 97-0126 Paga 1 of 2 e
ATTACHMENT III ENVIRONMENTAL IMPACT DETERMINATION
_- 1
Attachment III to ET 97-0126 Page 2 of 2
. Environmental Impact Determination 10 CFR 51.22(b) specifies the criteria for categorical exclusions frem the requirement for a specific environmental asressment per 10 CFR 51.21. This amendment request meets the criteria specified in 10 CFR 51. 22 (c) ( 9) as specified belows (i) the amendment involves no significant hazards consideration As demonstrated in Attachment II, the proposed change does not involve any significant hazards consideration.
(ii) there is no significant change in the types or significant increase in the amounts of any effluents that may be released offsite The proposed change does not involve a change to the facility or operating procedures that would cause en increase in the amounts of effluents or create 1ew types of effluents.
(iii) there is no significant increase in individual or cumulative occupational radiation exposure l The proposed change relates to venting of the ECCS piping to minimize voiding.
- This change will not increase any oc
- :upational rt.diation exposure, either individual or cumulative.
Based on the above, it is concluded that there will be no impact on the environment resulting from this change and the change meets the criteria specified in 10 CFR 51.22 for a categorical exclusion from the requirements of 10 rR 51.21 relative to requiring a r.pecific environmer.tal assessment by the Coma 'sion.
I Attachm:nt IV to ET 97-0126 Pags 1 of 3 ATTACHMENT IV PROPOSED TECHNICAL SPECIFICATION CHANGES CURRENT TECHNICAL SPECIFICATIONS
\) h a
' '