Text

North Carolina State University, License Amendment Request
	ML23212A973
Person / Time
Site:	North Carolina State University
Issue date:	07/31/2023
From:	Hawari A; North Carolina State University
To:	; Office of Nuclear Reactor Regulation, Document Control Desk
References
	Download: ML23212A973 (1)
	v • d • e

bv Nuclear Reactor Program Campus Box 7909 Department of Nuclear Engineering 2500 Stinson Drive https://nrp.ne.ncsu.edu/ Raleigh, NC 27695-7909 919.515.7294 (voice) 919-513-1276 (fax)

July 31, 2023 U.S. Nuclear Regulatory Commission Document Control Desk Washington,DC SUBJECT License Amendment Request License No. R-120 Docket No. 50-297 A license amendment for Technical Specification (TS) changes regarding reportable events is being requested.

Reportable event number 55747 occurring on February 17, 2022 and reportable event number 56553 occurring on June 2, 2023 at this facility were made since the current definition given in TS for a reportable event does not allow credit for prompt remedial action as permitted in Section 3 (Limiting Conditions for Operation) of the TS. Both the TS definition and TS Section 3 are changed to be based on the definition of special reports given in ANSI 15.1-2007.

If you have any questions regarding this report or require additional information, please contact Gerald Wicks, Acting Manager of Engineering and Operations, at (919) 515-4601 or wicks@ncsu.edu.

I declare under penalty of perjury that the forgoing is true and correct. Executed on 31 July 2023.

Sincerely, Ayman I. Hawari, Ph.D.

Director, Nuclear Reactor Program

Enclosures:

Attachment 1: Technical Specification Amendment 21 Line Changes and Justification Attachment 2: Technical Specifications Amendment 21 (affected pages with change bars)

Attachment 3: Technical Specifications Amendment 21 (affected pages clean copy)

Technical Specification Amendment 21 Line Changes and Justification Technical Specification Amendment 21 Line Changes and Justification 31 July 2023 Changes to the Technical Specifications for the North Carolina State University PULSTAR Reactor are described below. Each change is noted along with justification of the change.

1. Cover sheet 1 revised.

2. Headers on revised pages are changed to Amendment 21 and the submittal date.

3. Page 4 TS definitions Definition for Specification 1.2.24 d is revised based on Section 6.7.2.(1)(c)(ii) from ANSI 15.1-2007 . Additional text is added for prompt remedial action to TS 1.2.24 d.

1.2.24 Reportable Event: A Reportable Event is any of the following:

a. Violation of a Safety Limit.

b. Release of radioactivity from the site above allowed limits.

c. Operation with actual Safety System Settings (SSS) for required systems less conservative than the Limiting Safety System Settings (LSSS) specified in these specifications.

d. Operation in violation of Limiting Conditions for Operation (LCO) established in these Technical Specifications, unless prompt remedial action is taken as permitted in Section 3.

e. A reactor safety system component malfunction which renders or could render the reactor safety system incapable of performing its intended safety function unless the malfunction or condition is discovered during maintenance tests or periods of reactor shutdown. (For components or systems other than those required by these Technical Specifications, the failure of the extra component or systems is not considered reportable provided that the minimum number of components or systems specified or required perform their intended reactor safety function.)

This change is based on ANSI 15.1-2007 Section 6.7.2(1)(c)(ii) which states the following for special reports:

operation in violation of limiting conditions for operation established in the technical specifications unless prompt remedial action is taken as permitted in Sec. 3 In reportable events 55747 and 56553 for the PULSTAR reactor no credit for prompt remedial action was able to be taken because of the current wording used in TS 1.2.24 d. In both reportable events the appropriate and safe response to shutdown the reactor immediately occurred since a required channel for reactor operation became inoperable. Having this revised wording for TS 1.2.24 d will prevent reporting similar events in the future where the correct response was taken.

4. Page 16 TS 3.3 Immediate reactor shutdown from an inoperable channel is added.

3.3 Reactor Safety System Applicability This specification applies to the reactor safety system channels.

Objective The objective is to require the minimum number of reactor safety system channels which must be operable in order to assure that the Safety Limits are not exceeded.

Specification The reactor shall not be operated unless the reactor safety system channels described in Table 3.3-1 are operable. If any required channel listed in Table 3.3-1 becomes inoperable while the reactor is operating, then the reactor shall be immediately shutdown.

TS 1.2.24 d with the requested change to TS 3.3 would not require reporting provided that TS 1.2.24 e does not apply. TS 1.2.24 e states the following:

A reactor safety system component malfunction which renders or could render the reactor safety system incapable of performing its intended safety function unless the malfunction or condition is discovered during maintenance tests or periods of reactor shutdown. (For components or systems other than those required by these Technical Specifications, the failure of the extra components or systems is not considered reportable provided that the minimum number of components or systems specified or required perform their intended reactor safety function)

An immediate reactor shutdown of the reactor in the specification statement is given in the proposed change to TS 3.3 for an inoperable channel with no time period allowed for prompt remedial action to restore the channel to operation. The circumstances for the channel becoming inoperable would need to be investigated to determine if the occurrence is reportable or not per TS 1.2.24 e regarding the capability of the channel performing its intended safety function.

With this change Reportable Event Number 56553 from the PULSTAR Reactor for the Safety Power Level channel would not have been reportable since the reactor was immediately shutdown and reactor power nction was not needed for the reactor power level at the time the channel was inoperable.

5. Page 18 TS 3.4 Reactor Instrumentation An additional statement is made in the specification regarding response time and reactor shutdown. A five minute limit is added to restore operation for an inoperable channel. This is taken as meeting the prompt remedial action statement from ANSI 15.1-2007. Five minutes allows for sufficient time to determine if the channel is inoperable from a condition that can be immediately fixed. These channels provide monitor and indicate conditions and have no reactor safety system function. None of these three channels being inoperable, either separately or together, would cause an accident or release of radioactive material or unacceptable radiation levels. If the channel is not restored, or instead of the five minute response, immediate shutdown of the reactor is required since TS 3.4 is no longer being met. In so doing, a reportable event is not required.

TS 3.4 a provides power indication by measurement of N-16 in the primary coolant in the reactor outlet piping. It is used to compare indications given by the reactor power monitor channels listed in TS 3.3. The power monitoring channels in TS 3.3 retain the ability to initiate a reactor SCRAM regardless of N-16 power measuring channel status.

TS 3.4 b. provides control rod positions. There are three control rods used to control reactor power. The shim rod is not in use. Lost of all three control rod position indications is unlikely. Reactor power is constantly monitored as required by TS 3.3. The power monitoring channels in TS 3.3 retain the ability to initiate a reactor SCRAM regardless of the status of control rod indication.

TS 3.4 c applies to differential pressure (dp) gauge operation. dp and main HVAC operation can be checked within five minutes. TS 3.6 footnote (3) allows for 30 minutes to investigate and correct loss of dp while the main HAVC is operating.

3.4 Reactor Instrumentation Applicability This specification applies to the instrumentation that shall be available to the reactor operator to support the safe operation of the reactor, but are not considered reactor safety systems.

Objective The objective is to require that sufficient information be available to the operator to assure safe operation of the reactor.

Specification The reactor shall not be operated unless the following are operable:

a. N-16 Power Measuring Channel when reactor power is greater than 500 kW

b. Control Rod Position Indications for each control rod and the Shim Rod

c. Differential pressure gauge for "Bay with Respect to Atmosphere" If any required reactor instrument listed in Specification 3.4 becomes inoperable while the reactor is operating, then the channel shall be restored to operation within 5 minutes or the reactor shall be immediately shutdown.

6. Pages 19 and 20 TS 3.5 Radiation Monitoring Equipment An additional statement is made in the specification regarding response time and reactor shutdown. A five minute limit is added to restore operation for an inoperable channel. This is taken as meeting the prompt remedial action statement from ANSI 15.1-2007. Five minutes allows for sufficient time to determine if the channel is inoperable from a condition that can be immediately fixed. These channels provide indication of conditions and have no reactor safety system function. If the channel is not restored, or instead of the five minute response, immediate shutdown of the reactor is required since TS 3.5 is no longer being met. In so doing, a reportable event is not required.

TS 3.5 footnote(1) applies if a monitor is inoperable. Potentially, a replacement monitor for those listed in TS 3.5 can be installed within five minutes. A replacement monitor is already in operation with indication and audible alarms in the control room for either the stack gas or stack particulate monitor. Stack sampling of particulates is not affected by the stack particulate monitor being inoperable since it has a separate sampling pump.

3.5 Radiation Monitoring Equipment Applicability This specification applies to the availability of radiation monitoring equipment which must be operating during reactor operation.

Objective To assure that radiation monitoring equipment is available for evaluation of radiation conditions in restricted and unrestricted areas.

Specification The reactor or vented fueled experiment shall not be operated nor shall irradiated fuel or irradiated fueled experiments that are not contained in a properly sealed and approved shipping container be moved within the reactor building unless the radiation monitoring equipment listed below and in Table 3.5-1 is operating.(1)(2)(3)(7)

If any required radiation area monitor in Table 3.5-1 becomes inoperable while the reactor is operating, then the channel shall be restored to operation within 5 minutes or the reactor shall be immediately shutdown.

Because of the added wording, footnotes (1) and (2) were moved from page 19 to page 20. No text changes were made to footnotes (1) and (2).

7. Page 22 TS 3.6 Confinement and Main HVAC Systems footnote (5)

An additional statement is made in the specification regarding response time and reactor shutdown. A statement for reactor shutdonwn within five minutes if the standby confinement is inoperable was added.

This is taken as meeting the prompt remedial action statement from ANSI 15.1-2007. Normally both filter trains are available during reactor operation. Therefore this change only applies if one filter train is out of service for maintenance or repair. If the channel is not restored, or instead of the five minute response, immediate shutdown of the reactor is required since TS 3.6 is no longer being met. In so doing, a reportable event is not required. The confinement system is activated on exceeding the alarm setpoints of the radiation monitors listed in Table 3.5-1. During this five minutes, radiation monitor readings are available in the control room and the reactor operator may activate the confinement system manually if there is any concern.

Other operations personnel are available during the five minutes to respond to determine if the confinement system is operable.

(5)

One filter train may be out of service for the purpose of maintenance, repair, and/or surveillance for a period of time not to exceed 45 days. During the period of time in which one filter train is out of service, the standby filter train shall be verified to be operable every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months if the reactor is operating with the Reactor Building in normal ventilation. If the standby filter train becomes inoperable, it shall be restored to operation within 5 minutes or the reactor shall be immediately shutdown.

8. TS pages 4, 16, 18, 19, 22 Line spacing adjustment were made to fit the text to the page.

Summary:

The requested changes to TS are consistent with acceptable standards and guidelines for Research and Test Reactors as given in ANSI 15.1-2007. The requested changes fulfill the corrective action given in Reportable Event Numbers 55747 and 56553 for the PULSTAR reactor regarding reportable events.

Technical Specifications Amendment 20 (Affected pages with change bars)

Appendix A Technical Specifications for the North Carolina State University PULSTAR Reactor Facility License No. R-120 Docket No. 50-297 Amendment No. 21 Date: July 31, 2023 Appendix A Amendment 21 Technical Specifications July 31, 2023 1.2.22 Reactor Secured: The reactor is secured when:

a. Either there is insufficient moderator available in the reactor to attain criticality or there is insufficient fissile material present in the reactor to attain criticality under optimum available conditions of moderation and reflection, or

b. The following conditions exist:

i. All scrammable neutron absorbing control rods are fully inserted, and ii. The reactor key switch is in the OFF position and the key is removed from the lock, and iii. No work is in progress involving core fuel, core structure, installed control rods, or control rod drives unless they are physically decoupled from the control rods, and iv. No experiments are being moved or serviced that have, on movement, a reactivity worth exceeding one dollar (730 pcm).

1.2.23 Reactor Shutdown: That subcritical condition of the reactor where the absolute value of the negative reactivity of the core is equal to or greater than the shutdown margin.

1.2.24 Reportable Event: A Reportable Event is any of the following:

a. Violation of a Safety Limit.

b. Release of radioactivity from the site above allowed limits.

c. Operation with actual Safety System Settings (SSS) for required systems less conservative than the Limiting Safety System Settings (LSSS) specified in these specifications.

d. Operation in violation of Limiting Conditions for Operation (LCO) established in these Technical Specifications, unless prompt remedial action is taken as permitted in Section 3.

e. A reactor safety system component malfunction which renders or could render the reactor safety system incapable of performing its intended safety function unless the malfunction or condition is discovered during maintenance tests or periods of reactor shutdown.

(For components or systems other than those required by these Technical Specifications, the failure of the extra component or systems is not considered reportable provided that the minimum number of components or systems specified or required perform their intended reactor safety function.)

Appendix A Amendment 21 Technical Specifications July 31, 2023 3.3 Reactor Safety System Applicability This specification applies to the reactor safety system channels.

Objective The objective is to require the minimum number of reactor safety system channels which must be operable in order to assure that the Safety Limits are not exceeded.

Specification The reactor shall not be operated unless the reactor safety system channels described in Table 3.3-1 are operable. If any required channel listed in Table 3.3-1 becomes inoperable while the reactor is operating, then the reactor shall be immediately shutdown.

Table 3.3-1: Required Safety and Safety Related Channels Measuring Channel Function Inhibits Control Rod withdrawal when

a. Startup Power Level(1) neutron count is 2 cps SCRAM at 1.3 MW (LSSS)

b. Safety Power Level Enable for Flow/Flapper SCRAMs at 250 kW (LSSS)

c. Linear Power Level SCRAM at 1.3 MW (LSSS)

Enable for Flow/Flapper SCRAMs at

d. Log N Power Level 250 kW (LSSS)

SCRAM when flapper not closed and

e. Flow Monitoring(2)

Flow/Flapper SCRAMs are enabled SCRAM at 450 gpm (LSSS) when

f. Primary Coolant Flow(2)

Flow/Flapper SCRAMs are enabled Pool Water Temperature

g. ALARM at 117 F Monitoring Switch Pool Water Temperature Measuring

h. SCRAM at 117 F (LSSS)

Channel

i. Pool Water Level SCRAM at 14 feet 2 inches

j. Manual SCRAM Button SCRAM

k. Reactor Key Switch SCRAM

l. Over-the-Pool Radiation Monitor(3) Alarm (100 mR/hr)

Appendix A Amendment 21 Technical Specifications July 31, 2023 3.4 Reactor Instrumentation Applicability This specification applies to the instrumentation that shall be available to the reactor operator to support the safe operation of the reactor, but are not considered reactor safety systems.

Objective The objective is to require that sufficient information be available to the operator to assure safe operation of the reactor.

Specification The reactor shall not be operated unless the following are operable:

a. N-16 Power Measuring Channel when reactor power is greater than 500 kW

b. Control Rod Position Indications for each control rod and the Shim Rod

c. Differential pressure gauge for "Bay with Respect to Atmosphere" If any required reactor instrument listed in Specification 3.4 a., b., or c. becomes inoperable while the reactor is operating, then the channel shall be restored to operation within 5 minutes or the reactor shall be immediately shutdown.

Bases The N-16 Channel provides the necessary power level information to allow adjustment of Safety and Linear Power Channels.

Control rod position indications give the operator information on rod height necessary to verify shutdown margin.

The differential pressure gauge provides the pressure difference between the Reactor Bay and the outside ambient and confirms air flow in the ventilation stream for both normal and confinement modes.

Appendix A Amendment 21 Technical Specifications July 31, 2023 3.5 Radiation Monitoring Equipment Applicability This specification applies to the availability of radiation monitoring equipment which must be operating during reactor operation.

Objective To assure that radiation monitoring equipment is available for evaluation of radiation conditions in restricted and unrestricted areas.

Specification The reactor or vented fueled experiment shall not be operated nor shall irradiated fuel or irradiated fueled experiments that are not contained in a properly sealed and approved shipping container be moved within the reactor building unless the radiation monitoring equipment listed below and in Table 3.5-1 is operating.(1)(2)(3)(7)

If any required radiation area monitor in Table 3.5-1 becomes inoperable while the reactor is operating, then the channel shall be restored to operation within 5 minutes or the reactor shall be immediately shutdown.

a. Three fixed area monitors operating in the Reactor Building with their setpoints as listed in Table 3.5-1.(1)(3)(4)

b. Stack particulate and stack gas building exhaust monitors continuously sampling air in the facility exhaust stack with their setpoints as listed in Table 3.5-1.(1)(3)(4)

c. The Radiation Rack Recorder.(5)

d. Vented fueled experiment exhaust gas radiation monitor continuously monitoring the experiment exhaust gas.(7)

e. Vented fueled experiment flow rate monitor continuously monitoring the experiment exhaust gas flow.(7)

Table 3.5-1: Required Radiation Area Monitors Monitor Alert Setpoint Alarm Setpoint Control Room 2 mR/hr 5 mR/hr Over-the-Pool 5 mR/hr 100 mR/hr West Wall 5 mR/hr 100 mR/hr Stack Gas 1000 Ar-41 AEC(6) 5,000 Ar-41AEC(6)

Stack Particulate 1000 Co-60 AEC(6) 5,000 Co-60 AEC(6)

Appendix A Amendment 21 Technical Specifications July 31, 2023 (1)

For periods of time, not to exceed ninety days, for maintenance to the radiation monitoring channel, the intent of this specification will be satisfied if one of the installed channels is replaced with a gamma-sensitive instrument which has its own alarm audible or observable in the control room. Refer to SAR Section 5.

(2)

The Over-the-Pool Monitor may be bypassed for less than two minutes during return of a pneumatic capsule from the core to the unloading station or five minutes during removal of experiments from the reactor pool. Refer to SAR Section 5.

(3)

Stack Gas and Particulate are based on the AEC quantities present in the ventilation flow stream as it exits the stack. Refer to SAR Section 10 for setpoint bases for the radiation monitoring equipment.

(4)

May be bypassed for less than one minute immediately after starting the pneumatic blower system.

(5)

During repair and/or maintenance of the recorder not to exceed 90 days, the specified area and effluent monitor readings shall be recorded manually at a nominal interval of 30 minutes when the reactor is not shutdown. Refer to SAR Section 5.

(6)

Airborne Effluent Concentrations (AEC) values from 10 CFR Part 20 Appendix B, Table 2.

(7)

Monitors for vented fueled experiments are only required to be operating while the experiment is in operation.

Bases A continued evaluation of the radiation levels within the Reactor Building will be made to assure the safety of personnel. This is accomplished by the area monitoring system of the type described in Section 5 of the Safety Analysis Report (SAR). Evaluation of the continued discharge air to the environment will be made using the information recorded from the stack particulate and stack gas monitors.

When the radiation levels reach the alarm setpoint on any single area, or stack exhaust monitor, the building will be automatically placed in confinement as described in SAR Section 5.

To prevent unnecessary initiation of the evacuation confinement system during the return of a pneumatic capsule from the core to the unloading station or during removal of experiments from the reactor pool, the Over-the-Pool Monitor may be bypassed during the specified time interval. Refer to SAR Section 5.

Stack gas and stack particulate setpoints are based on the Notification of Unusual Event Emergency Action Level (EAL) for potential released nuclides including Ar-41, Co-60, and fission products. Fission product AEC values are higher than those for Ar-41 and Co-60. Therefore, using Ar-41 and Co-60 AEC for the setpoints is conservative.

Appendix A Amendment 21 Technical Specifications July 31, 2023 (3)

During an interval not to exceed 30 minutes after a loss of dp is identified with Main HVAC operating, reactor operation may continue while the loss of dp is investigated and corrected. Refer to SAR Section 5.

(4)

Operability also demonstrated with an auxiliary power source.

(5)

One filter train may be out of service for the purpose of maintenance, repair, and/or surveillance for a period of time not to exceed 45 days. During the period of time in which one filter train is out of service, the standby filter train shall be verified to be operable every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months if the reactor is operating with the Reactor Building in normal ventilation. If the standby filter train becomes inoperable, it shall be restored to operation within 5 minutes or the reactor shall be immediately shutdown.

(6)

The public address system can serve temporarily for the Reactor Building evacuation system during short periods of maintenance.

(7)

When the radiation levels reach the alarm setpoint on any single area, or stack exhaust monitor, listed in Table 3.5-1, the building will be automatically placed in confinement as described in SAR Section 5.

Bases In the event of a fission product release, the confinement initiation system will secure the normal ventilation fans and close the normal inlet and exhaust dampers.

In confinement mode, a confinement system fan will: maintain a negative pressure in the Reactor Building and insure in-leakage only; purge the air from the building at a greatly reduced and controlled flow through charcoal and absolute filters; and control the discharge of all air through a 100 foot stack on site.

Section 5 of the SAR describes the confinement system sequence of operation.

The allowance for operation under a temporary loss of dp when in normal ventilation is based on the requirement of having the confinement system operable and therefore ready to respond in the unlikely event of an airborne release.

Appendix A Amendment 21 Technical Specifications July 31, 2023 :

Technical Specifications Amendment 20 (affected pages clean copy)

Appendix A Amendment 21 Technical Specifications July 31, 2023 Appendix A Technical Specifications for the North Carolina State University PULSTAR Reactor Facility License No. R-120 Docket No. 50-297 Amendment No. 21 Date: July 31, 2023

Appendix A Amendment 21 Technical Specifications July 31, 2023 1.2.22 Reactor Secured: The reactor is secured when:

a. Either there is insufficient moderator available in the reactor to attain criticality or there is insufficient fissile material present in the reactor to attain criticality under optimum available conditions of moderation and reflection, or

b. The following conditions exist:

i. All scrammable neutron absorbing control rods are fully inserted, and ii. The reactor key switch is in the OFF position and the key is removed from the lock, and iii. No work is in progress involving core fuel, core structure, installed control rods, or control rod drives unless they are physically decoupled from the control rods, and iv. No experiments are being moved or serviced that have, on movement, a reactivity worth exceeding one dollar (730 pcm).

1.2.23 Reactor Shutdown: That subcritical condition of the reactor where the absolute value of the negative reactivity of the core is equal to or greater than the shutdown margin.

1.2.24 Reportable Event: A Reportable Event is any of the following:

a. Violation of a Safety Limit.

b. Release of radioactivity from the site above allowed limits.

c. Operation with actual Safety System Settings (SSS) for required systems less conservative than the Limiting Safety System Settings (LSSS) specified in these specifications.

d. Operation in violation of Limiting Conditions for Operation (LCO) established in these Technical Specifications, unless prompt remedial action is taken as permitted in Section 3.

e. A reactor safety system component malfunction which renders or could render the reactor safety system incapable of performing its intended safety function unless the malfunction or condition is discovered during maintenance tests or periods of reactor shutdown.

(For components or systems other than those required by these Technical Specifications, the failure of the extra component or systems is not considered reportable provided that the minimum number of components or systems specified or required perform their intended reactor safety function.